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1
Karlfeldt, Fedje Karin. "Metals in MSWI fly ash : problems or opportunities? /." Göteborg : Chalmers University of Technology, 2010. http://publications.lib.chalmers.se/cpl/record/index.xsql?pubid=120763.
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Larsson, Rasmus. "Energy recovery of metallic aluminium in MSWI bottom ash : Different approaches to hydrogen production from MSWI bottom ash: A case study." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-95064.
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Most of the wastes in Sweden end up in incinerator plants. These trashes are full of metals, especially aluminium, which will not oxidize, they can’t always be recycled and they will instead oxidize in water and leak hydrogen gas to its surrounding. Estimations calculate it could be an average potential of around 40-50 kWh/ton of burnt trash. Ignoring the imported trash, the national recovery potential of Sweden’s 4,3 million tonnes of trash would then be equal to 170-220 GWh/year due to non-recyclable metals, which are currently going to temporary landfills. The requirements to harness this potential are technically simple, and can be achieved by a quick separation of the recyclables and the non-recyclables. This report will review the factors which increase the rate of reaction and study different ways of extracting the energy, by electrolysis, thermal treatment and mechanical mixing. This was done by taking small samples from the MSWI, owned by Umeå Energi AB, and putting them in small containers. While using the different methods, electrolysis, thermal treatment and mechanichal mixing, the amount of developed H2 gas over time was measured. The result shows that the best methods are mechanical mixing together with thermal treatment, where mechanical mixing seems to give the biggest effect of them two. The electrolysis did not work as intended, where there could be issues with the conductivity of the ash-mixture.
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Brodin, MArcus. "Leach tests on MSWI bottomash from CHP Dåva to reduceCu, Pb and Zn." Thesis, Umeå universitet, Kemiska institutionen, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-144145.
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Kumpiene, Jurate. "Role of soil organic matter for immobilisation of metals : treatment of leachate from MSWI bottom ashes." Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16842.
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In this thesis, the focus is laid on the ability of natural organic matter (OM) to serve as a metal stabilising agent. The metal contaminants investigated arise from the MSWI bottom ash leachate. Besides the high content of metals, elevated pH and salinity are characteristic for ash leachate that, in turn, can alter the functionality of OM. Batch and column leaching tests were used to study the retention capacity of substrates with different amount of OM. Also, field observations were made of the influence of ash leachate on soil and plants. In this case, ash leachate was generated under field conditions from an experimental road built on municipal solid waste incineration (MSWI) bottom ashes. It has been shown that copper, chromium, and lead retention is proportional to OM content of the substrates. Zinc retention showed to have the least dependence on OM. The metals were not leached in proportion to dissolved OM. Most probably several mechanisms were responsible for the retention of metals: (i) high concentration of Ca in ash leachate could lead to the formation of Ca-dissolved organic carbon (DOC) complexes that have the ability to precipitate some metals (ionic strength effect) and prevent metal transport; (ii) high solution pH could favour hydroxide formation and counteract the metal complexation with dissolved OM, as well as (iii) surface adsorption could contribute to metal retention. Despite the good metal retention capacity of OM, a continuous metal load will occupy binding sites of OM and therefore reduce its retention capacity. Metal retention capacity of rich in OM substrate could be improved by additional soil amendments and vegetation. Tolerant plant species that are capable to grow at high soil metal concentrations and immobilize pollutants within the root zone have a potential to be used for phytostabilisation of metal contaminated soil. Such plants are also associated with a low risk of the translocation of contaminants from soil through plant roots to shoots, i.e. from one media to another. Immobilization is not a technology for the removal of contaminants from soil but for the stabilization (inactivation) of potentially toxic metals. The aim of soil remediation is to reduce the contaminant exposure and spread. Then the reduced leaching, bioavailability, as well as ecotoxicity of metals as a result of phytostabilisation might be a proper solution. Development of suitable soil and amendment mixtures capable to retain broad range of metals and interaction of plants with stabilised matrix are the questions to be answered in the future research.Godkänd; 2003; 20070109 (mlk)
5
Lin, Sung-Hui, and 林松輝. "Anaerobic Co-digestion of Real MSW and MSWI Ashes." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/46329288816032120015.
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碩士朝陽科技大學
環境工程與管理系碩士班
97
Sustainable development has been the core concept in the agenda of earth summit in Rio de Janeiro, Brazil in 1992. The core values have been used as the principal guidelines to resolve environmental and climate change problems at the moment in 21th century. Taiwan is a small island comprised of 26.36% plain and higher than two thirds of hill and mountain. Due to the enhancement of living standard and consumption, municipal solid waste (MSW) has increased and MSW incinerator (MSWI) has been the primary treat method for the MSW. However, the residues generated from the incineration still account for 15% of original MSW volume. They need to be treated carefully to prevent the secondary pollution. MSWI bottom ash (MSW BA) and fly ash (MSW FA) have been used as aggregate, soil amendment, back fill and co-composting. In this study, MSWI bottom ash and fly ash were co-digested with MSW to investigate their possibility as landfill cover. Anaerobic bioreactors of 30 cm height with 15 cm * 15 cm bottom area were used to simulate the landfill sites. One liter of real MSW was placed on the bottom of the anaerobic reactors. Then, 0.6 liter of anaerobic sludge seeding was placed on it. Then, the designated MSWI BA, MSW FA and soil were placed on the anaerobic sludge seeding. This arrangement accounted for one layer and four layer of placement were used to conduct the experiment. The total 22 anaerobic bioreactors were placed on the oven maintained at 35℃. Gas production was recorded by water replacement daily. pH, ORP, EC, Sal were measured after 80 ml of leachate taken and filtration weekly. TS, VS, and COD and metals in leachate were measured monthly. Through gas production and anaerobic parameters, the suitable ratios of MSWI BA and FA with MSW co-digestion can be obtained. Results showed that gas production was found to be beneficial in soil 1500 g l-1, MSWI FA 60 g l-1, MSWI FA 40 g l-1, control, and MSWI BA 600 g l-1 bioreactors. The gas production was found to be in the order of soil 1500 g l-1 > MSWI FA 60 g l-1 > MSWI FA 40 g l-1 > control ≧ MSWI BA 600 g l-1. Other anaerobic bioreactors were found to be strongly inhibitory in the MSW digestion. pHs in the range of 6-8 were found to be suitable for MSW anaerobic digestion. Released metals in suitable range were thought to enhance the gas production. However, exact beneficial levels may need to be tested for clarity in the future work by individual metal or mixed metals added on the designated MSW anaerobic digestion.
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Lin, Hsuen-chun, and 林雪君. "Anaerobic Co-digestion of Organic Fraction of MSW and MSWI Ashes." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/70675465127364988757.
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碩士朝陽科技大學
環境工程與管理系碩士班
98
Abstract This study aims at investigating the effects of different dosed ratios of bottom ash (BA), fly ash (FA) and soil on their anaerobic co-digestion with MSW in anaerobic bioreactors. Anaerobic bioreactors were 30 cm height and 15 cm square of bottom area. Anaerobic bioreactors of 22 sets (BA and MSW, FA and MSW, Soil and MSW, BA and soil and MSW, FA and soil and MSW and two controls) were employed for the experiment. One liter of MSW was placed on the bottom of the anaerobic reactors. Then, 0.6 liter of anaerobic sludge seeding was placed on it. Then, the designated MSWI BA, MSW FA and soil were placed on the anaerobic sludge seeding. This arrangement accounted for one layer and four layer of placement were used to conduct the experiment. Anaerobic bioreactors were maintained at 35℃ suitable for anaerobic digestion. Anaerobic parameters such as biogas, pH, ORP, EC, alkalinity, volatile acids, COD, TS, VS and metals were measured daily, weekly or monthly. Results showed that soil addition, particularly 1500 g/L, could enhance bacterial activity and biogas production. FA/MSW of 40 and 60 g/L could improve the MSW biodegradation and biogas production. FA dose higher 100 g/L was found to inhibit the MSW biodegradation and biogas production. BA/MSW dose of 1000 g/L showed to have the biogas enhancement potential. Results showed that biogas production was found to be beneficial in soil 1500 g/L, MSWI FA 60 g/L, MSWI FA 40 g/L, control, and MSWI BA 1000 g/L bioreactors. The biogas production was found to be in the order of soil 1500 g/L > MSWI BA 1000 g/L > MSWI FA 60 g/L > MSWI FA 40 g/L > control. Except anaerobic parameters, biogas production stimulation or inhibition was thought to be related to the released metals levels beneficial or detrimental to the anaerobic community resulting to the various MSW biodegradation and biogas production.
7
Yang, Chao-Chuan, and 楊朝全. "The Gas Prediction of Biodegradable MSW with MSWI Ashes Addition by Using Backpropagation Neural Network." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/49kt49.
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碩士朝陽科技大學
環境工程與管理系碩士班
94
Municipal solid waste (MSW) treatment has been transferred from landfill to incineration associated with composting and recovery and recycling due to the lesser available land for landfill in Taiwan. However, the residues such as bottom ash and fly ash generated still account for a volume and weight ratio by up to 10 and 25%, respectively. Thus, the treatment and disposal of MSW incinerator (MSWI) ashes become another environmental issue and needs further treatment to prevent secondary pollution. MSWI ashes have been practiced for landfill cover for many countries including Taiwan. However, the reaction mechanisms of co-disposal are not fully clear and needs a theoretical and experimental investigation for a better understanding of baseline information to meet the practice requirement. This study examined the possible utilization of MSWI ashes in anaerobic bioreactors. In particular, using the experimental results such as gas generation rate and metals release from bioreactors to train and predict the trend by backpropagation network (BPN) is the major focus of this study. Results showed that bottom ash added ratio of 100 g l-1 and fly ash added ratio of 10 and 20 g l-1 has the potential to enhance the gas generation rate. This phenomenon brings the advantage of MSW faster biostabilization and potential energy recovery. The input parameters chosen were pH, conductivity, salinity, total solid, volatile solids, chemical oxygen demand, alkalinity, volatile fatty acids, microbes etc. The outputs selected were gas generation rate, Ca, K, Mg and Na. In order to optimize the predicting results, gas accumulation in control bioreactor (blank1) was used to train the learning number and to analyze the values of root mean square (RMS). Results showed that the stability could be obtained after 3500 training times. Thus, the training number was chosen as 5000 for the following modelling. In addition, the addition of related coefficient (R) greater than 1.2 was another screen condition to eliminate the insufficient data from the training and verification bioreactors. These screening conditions thereby resulted in the generation of suitable hidden layers and learning speed for the predicting modelling of BPN. The results of modeling in gas accumulation and alkali metals release were in a good agreement with the experimental results. The R values exceeded 0.95 and showed a high linear relationship. RMSs fell below 100 except the accumulation of Ca ions in the 20 g l-1 bioreactor. In the modelling of gas production per week and Ca release, all average Rs were above 0.8 and all RMSs were below 35 except the medium-high relationship in the 100 g l-1 bottom ash added bioreactor, Ca release in verification set of blank1 bioreactor and in training set of blank 2 bioreactor and verification set in 20 g l-1 fly ash added bioreactor. From these results, it is noted that prediction modeling was found better in gas accumulation than in gas production per week. Particularly, the output values by BPN model were closed to that of the experimental bioreactors. These phenomena indicated that suitable Ca release could enhance the gas generation rate which has been found in the ashes added bioreactors than in the blank ones in the first stage of MSW digestion.
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Chang, Cheng-Yuan, and 張正源. "Physical and chemical characterization of MSWI residues." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/18598375605417265260.
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Chiu, Hsun-ying, and 邱薰瑩. "Modeling biogas production from organic fraction of MSW co-digested with MSWI ashes in anaerobic bioreactors." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/04734988970880362467.
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碩士朝陽科技大學
環境工程與管理系碩士班
98
This study aims at investigating the effects of MSW incinerator fly ash (FA) and bottom ash (BA) on the anaerobic co-digestion of OFMSW with FA or BA. It also simulates the biogas production from various dosed and control bioreactors. Results showed that suitable ashes addition (FA/MSW 10 and 20 g L-1 and BA/MSW 100 g L-1) could improve the MSW anaerobic digestion and enhance the biogas production rates. FA/MSW 20 g L-1 bioreactor had the higher biogas production and rate implying the potential option for MSW anaerobic co-digestion. Modeling studies showed that exponential plot simulated better for FA/MSW 10 g L-1 and control bioreactors while Gaussian plot was applicable for FA/MSW 20 g L-1 one. Linear and exponential plot of descending limb both simulated better for BA/MSW 100 g L-1 bioreactor. Modified Gompertz plot showed higher correlation of biogas accumulation than exponential rise to maximum plot for all bioreactors.
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Chang, Yan-Chung, and 張燕宗. "The Gas Prediction of Biodegradable MSW with MSWI Ashes Addition by Using ANN and Grey Theory." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/t964q4.
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碩士朝陽科技大學
環境工程與管理系碩士班
96
Abstract The process of the increase of the waste problem is overloaded the carrying capacity of the environment when the living standard is in advance in the limited spaces in Taiwan. There are several waste disposals being used: the incineration, the buried underground, the compost, and the recycling. The ashes caused by the incinerator needs to be taken care of. Statistically, the amount of the needed incinerated waste has been 568 tons until the year of 95. Then, the generated amount of the ashes caused by the incinerator is about 102 tons. Even though the incineration is able to reduce the weight and the capacity of the waste, there are still a considerable amount of the ashes of 1/10 and 1/4 out of the original weight and the capacity of the waste. Consequently, the ashes disposal is still one of the important issues from the perspective of the environmental protection. Presently, ashes are being disposed becoming the building materials, the backfill, and the buried underground. According to the lab testing results, the ashes buried underground has proved to be able to stabilize and improve the result of the gas production. This further promotes the re-used value of the land and the energy resources of the methane. This study utilizes so called “Back-propagation Neural Network, BNN”and the “Grey Theory”approach to settle the output variables for the amount of the decomposition of the waste, which products gas. The gas production analysis uses PH, total alkali, TS, VS, VA, Ca, Mg, K, Na, Cd, Cr, Cu, pb, Ni, Zn to be input variables. From the other side of the Neural Network, the heavy metal shows the best result, the value of the estimated gas production and the value from the lab MAPE (Mean Absolute Percent Error) is below 58.61%. The next is alkali. The anaerobic proves to be the worse result. From the Grey Theory standpoint, the MAPE of the RGM (1,1) model is below 3.91%, in terms of the estimated gas production and the lab testing result. The RGM (1,1) model’s predicted ability is better than the Neural Network by comparison. The factors thru GM(1,N)shows that gas production is influenced mainly by PH, TS, VA, Mg, K, Cd, Cr, Cu, Pb, and Ni. PH, TS, VS, Mg,K, Cd, Cr, Cu, Pb, Ni shows the same result with the Neural Network analysis. Therefore, PH, TS, VS, Mg, K, Cd, Cr, Cu, Pb, Ni have become an important data for gas production from the buried underground.
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Su, Yech-Hwang, and 蘇月熿. "Leaching of Heavy Metals and Volatile Organic Compounds from MSW co-disposed with MSWI in Anaerobic Bioreactors." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/66929477600687396723.
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碩士朝陽科技大學
環境工程與管理系碩士班
96
This study investigates the effects of different ratios addition of municipal solid waste (MSW) incinerator (MSWI) ashes on MSW biodegradation by anaerobic bioreactor simulating landfill site. Particularly, the gas production of MSW, heavy metals and volatile organic acids (VOCs) in leachate that might be affected by MSWI ashes addition are the major consideration. The size of anaerobic bioreactor is 1.2 m high and 0.2 m wide and the working volume is ~34 liter. Organic fraction of MSW (OFMSW) is mainly comprised of office paper (30%), newspaper (30%), carton paper (35%) and organic food (5%). They were shredded into pieces with diameter less than 1 cm and blended with deionized water to make a total solids (TS) of 6%. This OFMSW is similar to typical MSW with C/N ratio of around 30-40. Fly ash (0, 20, 40, 60, 100 g/L) or bottom ash (0, 100, 200, 400, 600 g/L) with different ratios were used as landfill cover by four layer arrangement. From the results, it is found that fly ash addition ratios of 20 and 40 g/L and bottom ash addition ratios of 100, 200, 400 and 600 g/L had the potential to increase the MSW biodegradation and gas production. Cd, Cr, Cu, Pb, Ni and Zn concentration in the leachate of control bioreactor, bottom ash added bioreactor and fly ash added bioreactor with different ashes ratios addition were found to be ND-0.184, 0.003-0.598, ND-0.984, ND-0.822, ND-0.140 and ND-1.587 mg L-1. Among them, Cd release was found to have the potential to exceed the environmental regulation standard. It indicates that subsequent leachate treatment of heavy metals needs to be carefully evaluated. Except heavy metals, VOCs can be detected in leachate of anaerobic bioreactors. Toluene and 2-Butanone in the control bioreactor were measured to be ND-9.00 and ND-92.44 μg L-1 respectively. Toluene, 2-Butanone, 2, 2-Dichloropropane, and chloromethane were analyzed to be ND-5.52, ND-726.96, ND-1.57 and ND-1.52 μg L-1 in the bottom ash added bioreactors respectively. In addition, six VOCs of Toluene, 2-Butanone, 2, 2-Dichloropropane, Chloromethane, Dichloromethane and Bromochloromethane was detected to be ND-318.32, ND-85.69, ND-178.63, ND-1.89, ND-290.44, ND-1.87 μg L-1 in the fly ash added bioreactors, respectively. Total VOCs in leachates of control bioreactor, bottom ash and fly ash added bioreactors were found to be ND-101.44, ND-735.57 and ND-876.84 μg L-1 respectively. Results showed that proper addition of MSWI bottom and fly ash co-disposed or co-digested with MSW could enhance the gas production. However, heavy metals, VOCs and other micro-pollutants released from bioreactor or landfill need to be thoroughly assessed and carefully treated to prevent secondary pollution. Through integrated assessment and treatment, the effects of released pollutants on human health and ecological environment can be reduced.
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Huang, Chin-Ming, and 黃錦明. "Decision-Making Process for MSWI Bottom Ash Utilization." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/91796145120323106905.
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博士國立臺灣大學
環境工程學研究所
95
The Taiwan Environmental Protection Administration has studied the treatment and reuse of MSWI ashes for many years and collected references on international experience accumulated by developed nations for establishing policies on treatment and reuse of MSWI ashes. The total number of incinerators is expected to increase to 27 with treatment capacity of 27,450 tons per day in service, operated daily to generate about 6,500 tons of incinerator bottom ash and 1,500 tons of incinerator fly ash, serving almost all cities in Taiwan by 2007. The citations were analyzed as the basis for current governmental decision making on policies and factors to be considered for establishing decisions on recycle and reuse of MSWI ashes. Feasible applications include utilization of ashes, which after sieving and separation of metal particles, produce secondary construction materials. When secondary construction materials comply with TCLP limitations, they can be utilized as cement additives, asphalt aggregate or road base. The decision making procedures of evaluation have been proposed in the performance criteria, health risk assessment, ecological risk assessment, to be included in the proposed process of ash utilization. This study was associated with the assessment of CLSM with bottom ash. The assessment method that combines engineering criteria and risk assessment, then be used to select the available substitution ratio for practice. The results were showed best condition was C/W 0.4, W/S 0.35∼0.40. Therefore, the achievements of the study could serve as the basis for the decision making and risk management related to reuse of bottom ash. The health risk assessment of CLSM with bottom ash were evaluated, the cancer risk of exposure route under construction and road service was lower than 10-6, and hazard quotient for noncancer was lower than 1. The physical and environmental properties of asphalt mixtures using various incinerator bottom ash as fine aggregate substitution were investigated. The Marshall mix design method was used to determine the asphalt content and evaluate the potential performance of IBA–asphalt mixtures. Leachates, from laboratory and outdoor leaching tests, were measured the concentration of heavy metals and daphnia toxicity. While with adequate Marshall stability, the IBA–asphalt mixtures were shown to have excessively high Marshall flow and excessively low VMA. The results of the wheel tracking tests indicated that the mixtures had low rutting resistance. The results of the water sensitivity test showed that the mixtures had a higher tensile strength ratio. Considering the environmental compatibility, the outdoor leachates showed that IBA had a high level of daphnia toxicity. From the ecological risk perspective, IBA could be identified as hazardous waste. However, after being mixed with asphalt, the concentration of heavy metals and the levels of daphnia toxicity were significantly reduced. The leachates of 10-day flat plate leaching tests indicated that the heavy metal were undetectable and the daphnia toxicity was ineffective. The IBA substitution rate would be suggested as less than 25% for surface course and less than 50% for base course To address public concerns, TEPA has adopted stringent regulations to reduce risk in bottom ash utilization and minimize the emission of pollutants in the flue gas from MSWI. In addition to providing technical guidelines for bottom ash utilization, TEPA has initiated the demonstration projects for obtaining field data to affirm the utilization policy and to revise the technical criteria, if needed. In this way, risk in the whole utilization process will be minimized, and the benefit and cost-effectiveness of the selected strategies on utilization will be maximized. The author offers the decision making process for the utilization of bottom ash with the engineering specification, environmental risk and ecological risk.
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Wu, Ming-Che, and 吳明哲. "Pretreatments on the Leaching Behaviour of MSWI Bottom Ash." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/45263431975497118026.
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碩士輔英科技大學
環境工程與科學系碩士班
99
Pretreatments on the Leaching Behaviour of MSWI Bottom Ash Abstract Toxicity characteristic leaching procedure (TCLP) has been the primary environmental validation protocol for reused MSWI bottom ash in Taiwan. Nevertheless, TCLP is originally developed for the identification of hazardous wastes; it is not suitable for the investigation of the leaching potential of recycled products. In order to evaluate long term leaching potential and environmental risk of heavy metals from reuse of MSWI bottom ash; percolation test (CEN 14405), pH dependent test (CEN 14429), availability leaching test (NEN 7341) were conducts on the MSWI bottom ash with pretreatments (water-washed and phosphate acid pretreated). Immissions of ashes were calculated and compared with Building Material Decree (BMD). Also leaching of heavy metals to the soil was simulated with LeachXS-Orchestra expert system for the risk assessment. Results show that MSWI bottom ash sampled (BAB) contain majorly silica, calcium, aluminum and iron elements. TCLP results show that BAB meets the Taiwan current regulation standard. Observation on the water-washed bottom ash (BAW) and phosphate acid treated bottom ash (BAP) shows that pretreatment with phosphate acid could effectively reduce the leaching concentration of Zn to 1.61 mg/L. Calculations from the percolation data indicate that immission could meet BMD category I and category II standard, though small amount of Mo and Sb might leach out from BAB and BAW, and tiny amount of Sb might leach out from BAP. Further comparison on the stabilization of heavy metal ability reveals that BAP>BAW>BAB. Simulation with LeachXS-Orchestra expert system indicates though Mo and Sb could penetrate the underneath soil layer, the concentrations are insignificant. Other element such as As,Cd,Ni,Pb and Zn are confined in the surface layer of soil ( 0 cm ~ 50 cm). In conclusion, stabilized MSWI bottom ash is environmental compatible, and it could be reused as recycled products. Key words: Pretreatments, MSWI bottom ash, Leaching behaviour, LeachXS-Orchestra.
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Tzeng, Bor-Yu, and 曾博榆. "Hydration Characteristics of MSWI Ashes Modified Slag Blended Cement." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/84616308271529480885.
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碩士國立中央大學
環境工程研究所
90
This study investigated the pozzolonic reactions and engineering properties of municipal solid waste incinerator (MSWI) ash modified slag blended cements (SBC) with various replacement ratios. The modified slags were characterized by melting the MSWI ash mixtures at 1,400℃ for 30 min. The mixtures were composed of different types of MSWI ash, including fly ash, scrubber ash and bottom ash, with various formulas. Bottom ash and scrubber ash, in general, have higher melting points, and are more energy intensive to melt than fly ash. Therefore, fly ash was used to modify the mixtures. The obtained slags were divided into three series based on the experimental ash mixtures. Following further pulverization, these slags were blended with cement at cement replacement ratios ranging from 10% to 40%. The slags thus obtained were quantified and the characteristics of their SBC pastes examined, including the pozzolanic activity, compressive strength, hydration activity, gel pores, crystal phases, species, and the microstructure at various ages. The results indicate that the slag contained 27∼34% CaO, 29∼39% SiO2, and 8∼23% Al2O3, and approximately 47∼67% non-calcium compounds, thus meeting the ASTM C grade for fly ash, which is similar to that of the blast furnace slag. The 90-day compressive strength developed by SBC pastes with a 10% and 20% cement replacement by slags generated from the modification of scrubber ash, outperformed that of ordinary Portland cement(OPC) by 1-7 MPa, whereas the slags generated from the modifications of bottom ash series were comparable to OPC with a difference of less than 0.5MPa. From the pore size distribution, as shown by the MIP results, it was found that, with increasing curing ages, the gel pores increased and the total porosity and capillary pores decreased ─ a result that shows that hydrates had filled the pores. XRD and DTA species analyses indicated that the hydrates in SBC pastes were mainly CH, the calcium silicate hydrate C-S-H(C-S-H) gel, and C-A-H salts, like those found in OPC paste. TG analysis also indicated that the slag reacted with CH to form C-S-H and C-A-H. The average length (in terms of the number of Si molecules) of linear polysilicate anions in C-S-H gel, as determined by NMR, indicated an increase in all SBC pastes with increasing curing age, which outperformed that of OPC at 90 days. The generation of C-S-H gel, with intersections forming a network structure, as observed by SEM from the surface reaction with CH, also indicated the later development of strength in SBC pastes enhanced by the slag. It can be concluded from the study results that MSWI ash can be modified and processed by melting to recover reactive pozzolanic slag, which may be used in SBC to partially replace cement.
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Tsai, Tsung-Hsun, and 蔡宗勳. "The study of sintering treatment of MSWI fly ash." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/06429439269148233515.
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碩士國立中興大學
環境工程學系
93
Abstract The quantities and varieties of solid wastes have increased rapidly, due to the growth in the industry and commerce. The incineration has become the major process to treat municipal solid waste due to the high volume reduction and energy recovery. About 20 municipal waste incinerators operate in Taiwan, and produce a large amount of the bottom ash and fly ash. Hazardous fly ash was generated from the incineration process due to the high proportion of heavy metal existing in input waste. Solidification of fly ash and subsequent landfill disposal has been widely applied to treat incinerator fly ash in Taiwan. However, the landfills have been applied for many years and the capacity approaches the upper limit gradually. Resource recycling is a promising concept for the solid waste treatment and receive more attention in the recent research. The sintering process seems to be a potential technology to handle the incineration ash, and has been used to the treatment of sewage sludge, sedimentary sludge and incineration ash in MSWI. The main purposes of sintering process are which effectively lower the dissipation rate of hazardous materials and hope to resource recycling. Most of research of sintering is focused on batch study. The main objective of this study is to investigate the continuous sintering behavior of fly ash with a rotary kiln. The operating conditions are as follows: (1) the different sintering temperatures and (2) operation time. The differences between the continuous and batch system will also be examined to provide an actual consultation in plants. The main purpose of the study focuses on finding a simple and economic process to treat MSWI fly ash.
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Liu, Chien-Chung, and 劉建中. "Microwave-assisted Acid Degradation Treatment of MSWI Fly Ash." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/zk2q46.
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博士國立臺北科技大學
工程科技研究所
101
The refuse disposal strategy of Taiwan has adoped incineration as the primary method of treatment with landfills as supplement. Fly ash discharged from municipal solid waste incinerators (MSWI) was classified as hazardous waste because the leashing of heavy metals (especially Pb) and the content of PCDDS/FS are usually over the regulation limits, so it was majorly treated by Solidifition/Stabilization method, after that sent to the landfills for final disposal. Such way will caused the serious loading of limited landfills capacity and also affected the implementation of Zero Waste Policy. This study fouced on using the microwave-assisted acid degradation treatment (MDT) to reduce the hazardous materials (Pb and PCDDS/FS) simultaneously. The fly ash after MDT will be harmless and easily be resused. Microwave-assisted acid degradation treatment has the advantages of uniform heating, quick reaction, low power consumption and effect reduction of hazardous materials. The fly ash (FA) and reaction ash (RA) used in this study were sampled separately from a domestic large-scale MSWI in northern Taiwan. They were tested by physical and chemical properties but only the RA was used for MDT test. The MDT method usesd an acid combination of H2SO4 (17.8M) for its high boling point and HNO3 (15.6M) for strong oxidation power, and tested with different reaction time and temperature in the same conditions of solid/liquid ratio (1/10) and 600W. It is found that the TCLP-extractable concentration of Pb will decrease with the increases of both treatment time and temperature, especially the reduction efficiency is significant in the early time of reaction. In the case of treatment temperature of 433°K, the reduction efficiency can reach 98.5％ after treatment time of 16 minutes. It is equivalent to the TCLP-extractable lead concentration of 46.2 mg/L in raw fly ash is down less than 0.69 mg/L, which is very lower than the hazardous regulation limit in Taiwan (5.0 mg/L). This work took the experimental data for correlation, and obtained the correlation equation between reduction efficiency and treatment time and temperature with a square correlation coefficient of 0.9401 as following: η(%)= 1-exp〔-30‧t‧exp (-2,210/T)〕. This equation can be used to estimate the reduction efficiency (η) for different temperature and time by the MDT in order to choose the effective operating conditions that make sure the fly ash after treatment is below the legal limits. The toxic equivalent concentration of PCDDS/FS has dropped to 0.00047 ng-I-TEQ/gdw (reduction efficiency is 99.94%) after MDT with the same test conditions above but higher solid/liquid ratio (1/20), which means that the MDT also get good reduction efficiency for PCDDS/FS in fly ash. In this study, on the basis of 100 tons / day for MDT plant scale, with a subsequent two-stage washing units, the treatment cost is 6,877 NTD / ton. The fee is higher than solidifition method (3,758 NTD / ton) and two-stage water washing method (3,939 NTD / ton), but lower than the melting technology (10,049 NTD / ton). The most important advantage of MDT is that the major hazardous substances of heavy metals and PCDDS/FS in fly ash could be reduced effectively so that the fly ash after treatment will be harmless and beneficial for recycling and utilization. It is worthing on the follow-up application.
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Tsai, Meng-Han, and 蔡孟翰. "Influence of sulphate on MSWI ash for cement sintering." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/71886735534303218690.
Full textAbstract:
碩士輔英科技大學
環境工程與科學系碩士班
94
MSWI ash is primarily composed of silicates, aluminum, calcium and iron oxides that are similar to the composition in cement raw materials. Utilization of MSWI ash as replacement of cement raw materials should be one possible strategy on waste reus. This research is aimed to study the application of bottom ash, fly ash and reaction ash to reuse for cement sintering. The inferferring factors for cement production by MSWI ash were also discussed. Experimental results show that sulphate and chlorine contained in the reaction ash and fly ash was so high that hindered the formation of C3S and β-C2S during the calcination of cement clinkers. Chlorine is belong to flux in clinkering, therefore too high content can cause clinkers melting. In this study, water wash pretreatment of reaction ash and fly ash was performed, and it was effective for the removal of chlorine. Then, the interference for cement sintering caused by chlorine can be reduced. Sulphate can response to produce γ-CaSO4 with calcium during the sintering, a too high coutent can influence the formation of C3S and β-C2S. Therefore, sulphate content should be a control factor for the reuse of MSWI ash for cement sintering, since it can hinder the formation of C3S and β-C2S during the calcination of cement clinkers.
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Hsu, Hsiao-Hsein, and 徐孝先. "Preparation and Characterization of Micro-nanoscale MSWI Ash and the Effects of Their Metal Release on MSW Anaerobic Digestion." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/38181463068967157032.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
96
This study investigates the preparation of micro-nano scale municipal solid waste (MSW) incinerator (MSWI) ashes and characterizes their metal content and metal compounds. In addition, MSWI ashes and micro-nano scale MSWI ashes are used to co-digest them with MSW in anaerobic bioreactors for comparison. Micro-nano scale MSWI ashes are ground with ball mill (PM 100) by physical grinding. Metal element, particle sizes and microstructure of MSWI ashes including micro-nano scale are measured by field emission scan electrical microscopy (FE-SEM) and X ray energy dispersive spectrometry (EDS). Metal compounds are analyzed by X ray powder diffractometry (XRPD). In addition, MSWI ashes including micro-nano scale are co-digested with MSW to observe the potential enhancement or inhibition of MSW biodegradation. Mixtures of 350 mL refuse substrate and 100 mL sludge seeding are added into the 500 mL anaerobic bioreactors. MSWI fly ash (including micro-nano scale) added ratios onto MSW are selected to be 0.12, 3, 6, 18 and 30 g g-1 VS respectively. Similarly, MSWI bottom ash (including micro-nano scale) added ratios onto MSW are selected to be 0.6, 12, 36, 60 and 120 g g-1 VS respectively. All anaerobic bioreactors are in duplicate and total bioreactors are 42 including 2 control ones. Gas production from bioreactors is recorded daily. Daily measurements also contain pH, ORP, EC, Salinity. Weekly analyses include COD, TS, TVS and metals. These measured parameters are used to evaluate the performance of anaerobic bioreactors with different ratios of MSWI ashes addition. At final stage of anaerobic digestion, solid digestate is taken out for parameters analyses such as C, N, H, P, K, pH, C/N, K2O, P2O5, TCLP and metals. These measured parameters will be used to assess the utilization possibility as organic fertilizer and as soil amendment in agricultural and forest. Results show that intensity of SiO2, CaCO3, PbO and ZnS increased after grinding. However, intensity of Al2O3 and CaMg(CO3)2 were found to decrease. Particle sizes less than 100 nm were found to increase. With regard to co-digestion of MSWI ashes and MSW, gas production of MSWI bottom ash/MSW ratios (BA/MSW ratios) of 12, 36 and 60 g g-1 VS (2177.5, 2492.5, 1970 mL) and MSWI fly ash/MSW ratios (FA/MSW ratios) of 6, 18 and 30 g g-1 VS (1917.5, 1985, 2047.5mL) were found to be higher than control one (852.5 mL). Gas production of similar ratios of MSWI micro-nano scale bottom ash/MSW (NBA/MSW ratios) and similar ratios of MSWI micro-nano scale fly ash/MSW (NFA/MSW ratios) were found have higher gas production than that in the BA and FA added bioreactors. NBA/MSW ratios of 12, 36 and 60 g g-1 VS and NFA/MSW ratios of 6, 18 and 30 g g-1 VS were found to have gas production of 2300, 2705 and 2465 mL and 2132.5, 2070 and 2170 mL respectively. Heavy metals released from the added ashes in the anaerobic bioreactors were found to have the order of Zn (0.0061-4.8661 mg l-1) > Cr (0.0048-2.8715 mg l-1) > Cu (0.0047-0.8867 mg l-1) > Ni (0.0057-0.2211 mg l-1) > Cd (0.0085-0.142 mg l-1) > Pb (0.0049-0.1368 mg l-1). Released levels of heavy metals from ground MSWI ashes were found to be higher than those of unground ones. It indicates that ground MSWI ashes have smaller particles than unground ones resulting in the higher adsorption of heavy metals on MSW. It is also thought that suitable levels of trace metals nutrients may be released from ground ashes resulting to a higher gas production than that of unground ones. For resource purpose, solid digestate of co-digestion mixture were measured to have suitable pH and C/N ratios indicating its suitability for organic fertilizer or soil amendment. It is therefore concluded that micro-nano scale MSWI ashes can be achieved by physical grinding. Suitable ratios of micro-nano scale ashes to MSW could enhance higher gas production than that of unground ashes. These results can be for reference to co-digestion or co-disposal of MSW and MSWI ashes.
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Fu, Tsu-Ying, and 傅祖營. "The Environmental Impact of MSWI Ashes Co-Disposed with MSW on Landfill -A Case Study on Taichung City Landfill." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/k2myhs.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
94
Municipal solid waste (MSW) has mostly been treated by incineration than by landfill in Taiwan due to the less suitable sites for landfill. However, the residues produced such as bottom ash and fly ash were another environmental concern due to the potential hazardous substance content which might cause human and environmental risk when improperly disposed. Thus, the management and disposal of MSW incinerator (MSWI) bottom ash and fly ash become emergent environmental issues in Taiwan, This study aims to collect the amount of MSWI ashes entering the landfill and survey the treatment methods by Taiwan and foreign countries. Particularly, the leachate parameter levels from experimental anaerobic bioreactors were analyzed to compare the landfill leachate, effluent, groundwater and soil of a selected Taichung city landfill co-disposed with MSW and MSWI ashes. Further assessment of human and environmental risk was discussed. From these results, several conclusions can be drawn: 1. Heavy metals content of Cd, Cr, Cu, Ni, Pb and Zn in the soils was found below the Taiwan regulatory standard. However, the long term accumulation and human and environmental risk need further long term monitoring and investigation. 2. COD, SS, Cd, Cr, Cu, Pb and Zn in leachate were found to have insignificant differences in raw MSW and MSW co-disposed with MSWI ashes landfills. These phenomena were also found similar as compared to a northern MSW landfill co-disposed with MSWI ashes. These results is worthy of further investigation. 3. Due to the less appropriate land for landfill and the effect of “not in my back yard”, MSWI ashes were treated toward the direction of recovery and recycling. Therefore, the screening plant for MSWI bottom ash recovery and reutilization might need to be developed and implemented for extension of landfill expectancy. 4. At pH 6.5~7.5, the heavy metal release was found slightly higher in bottom ash added bioreactors than in fly ash added ones. All released heavy metals in the ashes added bioreactors were found below Taiwan regulatory standard with the exception of Pb, This implied that MSWI ashes might show potential beneficial rather than detrimental effects on landfill co-disposal with MSW. 5. Heavy metals released levels from landfill bioreactors and real landfill site showed insignificant differences except Ni and Pb. This result might be attributed to be the potential similar functional groups in MSW and sludge components resulting to heavy metals of higher adsorption and lower release. 6. Volatile organic compounds in landfills particularly found in chlorinated compounds and polyaromatic hydrocarbons might exert hazardous and carcinogenic effects on human health and ecological environment. Thus, these potential human and environmental risks need further investigation.
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Chen, Cheng-Gang, and 陳政綱. "The Expansion Mechanism of Lightweight Aggregate Sinteringfrom MSWI Bottom Ash." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/35092861679758357404.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
95
Lightweight aggregate was produced by natural expansion material, e.g. pumice, shale, and clay. This study used a municipal solid waste incinerator (MSWI) bottom ash as the material to sinter an artificial lightweight aggregate.Comparing MSWI bottom ash with natural expansion material, we found that the compounds of MSWI bottom ash were complex and heterogeneous. Therefore adding SiO2 and Fe2O3 to the milling of MSWI bottom ash was necessary. And then we used different parameters of sintering to understand the quantity of the expansion gas during the sintering process. The experiment was divided into four parts. First experiment discussed the relation between the quantity of the expansion gas with Fe2O3 when fixed the quantity of MSWI bottom ash and specimens didn’t have deformed during the sintering process. Second experiment fixed the parameters of the sintering and comprehended the influence of adding SiO2. Third experiment, added 10% of fine grain MSWI bottom ash and Fe2O3 to coarse grain MSWI bottom ash, found the effect of adding the fine grain MSWI bottom ash. Final experiment discussed the effect of the form of the artificial lightweight aggregate in the different sintering atmospheres. The compounds of MSWI bottom ash for producing CO2 were more important than adding Fe2O3. In addition the reduction atmosphere was helpful to produce the high quality of the artificial lightweight aggregate.
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Liou, Chiung-Ling, and 劉瓊玲. "MSWI Reaction Ash Regeneration by Stabilization Accompany with Sintering Process." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/73617164545393128049.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
93
Municipal solid waste treatment method was treading toward incineration in Taiwan. A large amount of fly ash could be produced. The heavy metals concentration of fly ash failed to meet the EPA’s regulation of TCLP test thresholds. The de-toxicfication and stabilization for fly ash were necessary and the final aim is regeneration. This study was to develop a new process that could cheaply and stably treat the fly ash and regenerate the products. The process includes water-washing, phosphoric acid stabilization, and sintering. Washing could remove the soluble salts in the fly ash, which is harmful to the sintering process; the phosphoric acid could stabilize the heavy metals. The pretreated fly ash could be safely materialized by sintering technology. The study was found that fly ash after water washed twice, the soluble salt could remove 90%. After stabilized with proper dosage of phosphoric acid solution, the concentration of Pb were significantly reduced in the TCLP extract of the washed fly ash samples. Then the stabilized samples were mixed with designed percentage of water purification sludge and clay, and sintering at 1000 and 1100 0C. The sintered products could achieve the criteria for aggregate of construction that is possible to be regenerated.
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Wu, Kuan-Chung, and 吳冠中. "Study of MSWI Ashes as Coagulant on Landfill Leachate Treatment." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/20833896857181682480.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
97
Municipal solid waste (MSW) has been treated in major by incineration and in part by landfilling due to the scarce land in Taiwan. However, ashes such as bottom ash (BA) and fly ash (FA) generated from MSW incinerator (MSWI) still account for about 10-15% of original MSW. Thus, they need to be treated carefully to prevent the secondary pollution. In general, BA has been mostly used as aggregate, backfill, soil amendment and landfill cover. FA has also been used as additive aggregate or cement partly. However, it has been treated by solidification and stabilization in most case. Generally, BA and FA have been treated for utilization purpose. BA and FA contain large amount of Al and Fe oxide and have high specific surface. Therefore, they have the potential to be used as adsorbent and coagulant for landfill leachate treatment. In this study, jar test was used to test the suitability of FA and BA as a coagulant for leachate treatment. Water parameters analysis includes pH, ORP, EC, COD, NH4-N, PO4-3, color, SS and metals. Experimental operational conditions contained BA or FA/leachate ratios (0, 2, 4, 8, 16, 32, 64 g/0.1 L), pHs (1, 3, 5, 7, 9, 11, 13), agitation time (0, 5, 10, 20, 40, 60 min), and rotation speed (0, 20, 40, 80, 120, 200 rpm). After optimal test of operation parameters, BA was found to have the high treatment efficiency at the conditions of 2 g/0.1 L ratio, pH 7, 80 rpm, 25℃, 20 min. The removal efficiency was found to be in the order of COD (30%) > Color (24%) > SS (11%). Similarly, FA was found to have the high treatment efficiency at the conditions of 2 g/0.1 L ratio, pH 7, 40 rpm, 25℃, 5 min. The removal efficiency was found to be in the order of Color (70%) > COD (54%) > SS (42%). Using the optimal conditions of BA and FA, Al2(SO4)3 (700, 1400, 2800, 5600, 8000, 12000 mg l-1) and FeCl3 (30, 130, 430, 830, 1000, 2000 mg l-1) coagulants with different amounts were used to test their removal efficiency of leachate pollutants. In addition, pH adjusted to 7 and pH without adjustment after coagulants addition was conducted for comparison. Results showed that removal efficiency of PO4-3 and color could be reached as higher than 75% at the conditions of Al2(SO4)3 (1400 mg l-1) plus FA (16 g), FeCl3 (430 mg l-1) plus FA (16 g) and Al2(SO4)3 (1400 mg l-1) plus FA (4 g) plus FeCl3 (430 mg l-1) plus FA (4 g) without pH adjustment. It is also noted that removal efficiency of heavy metals higher than 65% was observed in most case. This phenomenon indicates that suitable amounts of combination of BA, FA, Al2(SO4)3 and FeCl3 can enhance the PO4-3, color and metals removal efficiency than any of them with only individual treatment test.
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鄭光志, Guang-Jhih Jheng, and 鄭光志. "Dechlorinate Pretreatment by Acid Washing for Recycling MSWI Bottom Ash." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/zb48ce.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
98
Because of the domestic incineration bottom ash reuse proportion elevates year by year and it’s reuse purpose also to be more and more extensively,therefore, before the incineration bottom ash uses again, processes also relative appears important, and how does this research mainly increase the acidic medicament by four section of continuous-type washing in elimination bottom ash water-soluble chloride ion in the type domestic laws and regulations stipulations (The bottom ash the water-soluble chloride ion to be lower than 0.024wt% according to the CNS1240 before bottom ash reusing) as well as reduces the cost to favor in the project effectively the utilization. This research by liquid solid ratio、time、and the increase acidic medicament''s quantity takes experiment''s three tremendous influence condition, finally discovered that the fore-mentioned three conditions the enhancement can increases the efficiency with the bottom ash the water-soluble chloride ion in elimination, namely time = 10 minutes、liquid solid ratio =1, and the increase the acidic medicament are the acid: water =1: 500, the bottom ash the water-soluble chloride ion density by 0.858% drop to 0.132% (to reduce the efficiency =84.6%); But when the condition enhances for time = 30 minutes、liquid solid ratio =3, the increase the acidic medicament is the acid: water =1: 100, the bottom ash the water-soluble chloride ion density drop to 0.021%, reduces the efficiency to reach as high as 97.4%. Base on this comprehensive judgment discover to increase weak acid medicament may promote the bottom ash the water soluble chloride ion elimination effect, and time = 30 minutes is the best process time by acid washing, but how much this micro weak acid medicament must increase suitable、and the work in the feature either process application still should still should regard the actual bottom ash application (or market) decide, according to this study initially estimate cost of this work is 505 dollars each ton, but its extends that the character changed of bottom ash、Wastewater disposal、and the process application stability all are the topics following discusses again
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Lin, Shiou-Yi, and 林修毅. "Resource of MSWI Fly Ash as Alternative of Cement Material." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/9xq4hs.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
101
MSWI fly ash is well known a hazardous industrial waste in the world, the characteristics of ash in cement slurry treated by promising technology - thermal degradation with salting precipitation are studied in this work , it can be efficient to reduce dioxin and Pb-metal to the legal limit. So we can not only accomplish “zero waste policy” but complete the “resources circulation.” Four characteristic of cement slurry were adopted to study the feasible of MSWI fly ash as alternative of cement material in this work. According to the results obtained, the detoxic ash addition increases the cement slurry initial and final setting time. Because of the hydration reduced ,more substitution of innoxious ash makes more drying shrinkage. Then we choose two mixture ratio: water cement ratio - substitution rate are 0.35-5 % and 0.37-10 % to compare their porosity, the total pore volume decrease 34.7 % and 47.6 % , the pore diameter decrease 28.4 % and 30.7 %. The compressive strength of cement slurry which substitution rate below 10% are 26.6 to 43.1 MPa. In this study, deduce this work that the slurry of low water cement ratio (0.30 to 0.37) and low substitution rate (5 % and 10 %) have more extension of application. Compare with the pre-treatment ways of MSWI fly ash, thermal degradation have higher cost than the solidification process with cement, but the beneficial from utilization also can keep the cost down, so this is worth of discussing in the future.
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Wei, Pei-Shou, and 魏培修. "Study on MSWI Fly Ash Solidified / Stabilized with Geopolymer Material." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/c8rk2g.
Full textAbstract:
碩士國立臺北科技大學
資源工程研究所
97
Because of amounts of heavy metals in municipal solid waste incinerator fly ash (MSWI fly ash), MSWI fly ash solidified/stabilized with cement and chelating agents was the major treatment technology of MSWI fly ash. However, even after solidification/stabilization, heavy metals in MSWI fly ash could be leached in the acidic condition. Therefore, it was utilized fly ash, metakaolinite, sodium silicate and alkaline solution to prepare fly ash geopolymerized solidification/stabilization matrices (FAGPSSM) in this study. The effects of curing time, SiO2/Al2O3 ratio and SiO2/Na2O ratio to compressive strength, heavy metals leachability and micro-structure of FAGPSSM would be investigated and long-term stability of heavy metals in FAGPSSM would be evaluated. The results indicated that the compressive strength and heavy metal leachability of FAGPSSM prepared with SiO2/Al2O3 and SiO2/Na2O ratio respectively 3.0 and 0.75 would be better. The leaching concentration of Pb in FAGPSSM cured after 28 days by TCLP method was lower than 0.1 mg/L and it showed that FAGPSSM could effectively immobilize Pb in MSWI fly ash. The spectra of 29Si and 27Al NMR implied that there were amorphous calcium silicate hydrate (CSH) gels and aluminosilicate gels both coexisting in FAGPSSM. The XRD patterns showed that the amount of crystallinity present was mainly caused by NaCl, Ca(OH)2, SiO2, CaCO3 and Ca2Al(OH)6Cl phases present in FAGPSSM. The spectra of FTIR indicated that the vibrational band at 941∼957 cm-1 was attributed to the Si-O-T (T=Si or Al) asymmetric stretching mode. The microstructures of FAGPSSM showed that the grain of FAGPSSM was compact and powder present on the surface of particle. The semi-dynamic leaching test (SDLT) was conducted to evaluate the long-term stability of Pb in FAGPSSM prepared with SiO2/Al2O3 and SiO2/Na2O ratio respectively 3.0 and 0.75 and cured after 28 days. The results carried out by SDLT showed that after 60 days extraction, the compressive strength of FAGPSSM would decrease from 14.6 MPa to 0.8 MPa, but the cumulative leaching percentage of the total Pb in FAGPSSM only reached to 40%. Therefore, it inferred that the long-term stability of Pb in FAGPSSM was better than in the cementitious solidified/stabilized matrix. The microstructures of FAGPSSM showed that the grain of FAGPSSM would become porous after 60 days extraction. The spectra of FTIR indicated that as extraction time increased, the vibrational band of Si-O-T (T=Si or Al) asymmetric stretching mode would shift to higher wavenumbers. After 60 days extraction, the structure of FAGPSSM would turn from the coexistence of the amorphous CSH gels and aluminosilicate gels to the aluminosilicate gels.
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Li, Yao-Hsin, and 李耀心. "Removal of Chlorides in MSWI Bottom Ash by Hydrothermal Treatement." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/29573333497261649865.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系所
104
Hydrothermal treatment is used water or solvents in a closed state as a liquid medium at high temperature and pressure conditions of a chemical reaction, which is low pollution, simple control method of pollution and simple operating conditions, is a treatment technology with great potential. Electrolysis can induce oxidative degradation, without adding additional chemicals. Which can be carried out at atmospheric pressure at room temperature and does not produce secondary pollution. In this study, using hydrothermal treatement combined with electrolysis technology to reduce bottom ash organic matter and other harmful substances, in order to achieve sound, reduction and other purposes. The research shows (1) after the hydrothermal treatment of bottom ash, sodium, aluminum, chloride content were decreased , wherein the chloride in residue was 4.1wt%, can be reduced 0.053wt%, but as the process temperature is further increased when the chloride content began to increase, which probably because chloride ions in solution leads to increased synthesis of KCl solid chlorine content. (2) bottom slag lead leaching will increase as the process temperature increases the dissolution hydrothermal treatment program may result in incineration bottom ash Pb mobility increases. Bottom Ash and all samples were less than the limit, so the bottom slag recycling is not part of lead leaching concerns. (3) bottom ash soluble chloride via the water after the heat treatment process, the chlorine content can be reduced up to 94%. Confirmed that the hydrothermal treatment could reduce the bottom ash soluble chloride.
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Tsai, Meng Chang, and 蔡孟昌. "Influence of Sulphates on MSWI Ashes as Cement Raw Material." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/07936908614601734540.
Full textAbstract:
碩士輔英科技大學
環境工程與科學系碩士班
97
CaO2, SiO2, Al2O3 and Fe2O3 are the major compositions of raw cement, during the high temperature to calcined as the cement materials. In Taiwan, municipal solid waste incinerator (MSWI) clinker’s chemical compositions are similar to cement raw materials, and can be the resource recycled. Nevertheless, sulphates in the MSWI ashes might affect the sintering process of cement crystalline. Further investigation is needed. Various forms of sulphates were added into the cement raw mixes, XRD analysis indicates that both the cement major crystalline phases (C3S and β-C2S) formations would be enhanced with CaSO4 addition is less than 2.76%. Nevertheless, with Na2SO4 and MgSO4 addition larger than 0.5% and 0.22%, the formation of C3S and β-C2S would be hindered. To exclude the influence of sulphates in the MSWI ashes on cement sintering, MSWI ashes are washes prior to mixed and sintered. XRD relative intensity to reference (RIR) analysis on the formation of C3S and β-C2S shows that washing procedure could effectively reduce the soluble sulphate content in MSWI ashes and enhance the formation of C3S and β-C2S.
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Kuo, Jung-Jen, and 郭容忍. "Recycling MSWI Ash as a Raw Material for Portland Cement." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/tj93pm.
Full textAbstract:
碩士國立交通大學
環境工程系所
92
In Taiwan, landfill disposal and solidification are two major strategies for MSWI ash disposal. However, MSWI ash is rich in heavy metals and salts, which may cause serious environmental problem if without proper treatment. Recently, cement industry has played an important role in the disposal of solid wastes because it can utilize various kinds of wastes as fuels or raw materials. In addition, the heavy metals can be safely captured in the cement clinker. In this study, the feasibility of incorporating MSWI fly ash and bottom ash into cement clinker was evaluated. Sintering process was attempted to simulate the cement making. The goal of this study is to find a practical way to dispose the MSWI ash. The chemical property of the incineration ash was analyzed. The MSWI ash was washed with water and acid to remove the chlorides in order to prevent the clogging and the rusting of the cement kiln. The greatest chloride removal was achieved by a 15 min water washing at L/S=10 followed by a 30 min wash with 0.1 M acetic acid at L/S=20. After the pre-treatment, various amount of the ash was added to replace the clay component of the cement raw material. The effect of its addition on sintering condition and the quality of the Portland cement were evaluated. The maximum percentage of fly ash and bottom ash could be added were 1.75﹪and 3.50﹪, respectively. The results showed that the compressive strength of the clinker with fly ash and bottom ash addition was similar to that of the blank sample. However, the setting time of the masonry was much longer. All cement products conformed to the Chinese National Standard of second degree Portland cement, with one exception that the setting time of the clinker was much longer.
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Lee, Chang-Sung, and 李昶松. "Calcium Recovery Technology for the Extraction Wastewater of MSWI Fly Ash." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33423522977395909890.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
97
MSWI fly ash contains a lot of chloride salt, if not be pre-treated properly, it will influence the feasibility of recovery as the construction materials. Water extraction is the most common operation, beside a lots of chloride salt could be removed; a large quantity of calcium ions will also be dissolute at the same time. In this study, CO2-sparging, lime softening and soda ash softening were exam in order to recovery the calcium carbonate from the extraction wastewater. Substitution, chemical precipitation and electro-aggregation method were discussed for the removal of heavy metals before the calcium recovery, in order to upgrading the characteristic of the product and satisfied the wastewater effluent standard. The results showed that, the effects of CO2-sparging and lime softening methods for Ca recovery were limited. When dosing the soda ash at 110% of theoretical quantity, the recovery of Ca was up to 98%. For heavy metals removal, substitution with alumni powder was ineffective, while the chemical precipitation at pH 10, the Pb in the water could be removed more than 99％, and electro-aggregation method at 125V, hydraulic retention time 60s, all of the heavy metals could reach the effluent standards. After the operation of chemical precipitation or electro-aggregation for pre-treatment, the soda ash dosing 100% of theoretical quantity, Ca recovery could reach more than 99.95%, and heavy metals were not detectable or far below the effluent standards. The XRD analysis showed that, pre-treatment of heavy metals could improve the purity of calcium carbonate product evidently.
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Chen, You-Ru, and 陳右儒. "Characterization of Micro-nanoscale MSWI Ash and reuse of lightweight aggregate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/86670113971321320886.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
99
Municipal solid waste (MSW) is mainly treated by incineration while part by recycling, anaerobic digestion and composting in Taiwan. Incinerator may reduce MSW volume and produce energy and electricity while it may also produce air pollution and bottom and fly ash problems. Bottom ash (BA) and fly ash (FA) contain metals such as cadmium, chromium, nickel, copper, zinc and lead that might cause risk to human health. Thus, the proper treatment of ashes and their potential reuse has become an important issue. This study aimed to investigate the incinerator ash preparation and characterization of micro-nano BA and FA and their potential reuse as lightweight aggregate. BA and FA were ground by ball mill (Retsch PM 100). They were further measured by high-performance laser particle path analyzer (HPPS) for particle size analysis. Five mixing ratios (BA:FA, 1:0, 3:1, 1:1, 1:3, 0:1) and three various sintering temperature (800℃, 1000℃, 1200℃) were adopted to conduct the experiment. The sintered BA and FA tested samples were further analyzed for toxicity (Toxicity characterisitic leaching procedure, TCLP) and Microtox test. Parameter analysis of sintered BA and FA (with various substitution rate of 0%, 20%, 40%, 60%, 80%, 100% of cement mortar by sand) included density, specific gravity, water absorption and compressive strength for potential light aggregate utilization. Results of this study can be drawn as following: 1. Cr dissolution in original BA and Cd dissolution in original FA exceeds the standard values (0.68 mg/L for Cr in BA and 0.1 mg/L for Cd respectively) while the dissolution of metals levels of sintered BA and FA met the regulatory standards. 2. Acute toxicity test (Microtox) of original ashes are shown below EC50 and EC20, however, micro-nano ground and non micro-nano ground sintered ashes showed minor toxicity and the toxicity was ground before > ground after. 3. Density and specific gravity were in the order of 1200℃ > 1000℃ > 800℃ while water absorption was 800℃ > 1000℃ > 1200℃. 4. Uniaxial compressive strength by sintering temperature showed the order of 1200℃ > 1000℃ > 800℃. Sintered non micro-nano ashes of FA:BA(3:1) showed the highest compressive strength while sintered micro-nano ashes of FA:BA(1:1) showed the highest compressive strength. In addition, replacement ratios of 20% and 40% by ashes showed the highest compressive strength.
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Guo, Tz-Hau, and 郭子豪. "Study on Pretreated MSWI Bottom Ash Utilized as Cement Raw Material." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/36864381491678991947.
Full textAbstract:
碩士國立成功大學
環境工程學系
89
In Taiwan, a large amount of municipal solid waste incinerator (MSWI) bottom ash (BA) is produced each year. MSWIBA is primarily composed of silicon, calcium, aluminum and iron oxides that are similar to cement raw materials. Utilization of MSWIBA as replacement of cement raw materials should be one possible strategy on waste reuses. However, bottom ash contains trace amount of interferences such as heavy metal, sulfate, and chloride. When cement raw material is replaced by MSWIBA, some of the interference might produce adverse effects on cement burning or hydration. In this research, three kinds of pretreatments (water-wash, EDTA-extraction, and heavy fluid separation) were taken on magnet-distracted (MD) MSWIBA to remove interferences indicated previously. Removal efficiency and best operating condition on burning were also investigated. Then, variant replacement percentage samples were burned with best operating condition separately. Finally, hydration characteristics of each burned sample were tested. Therefore, effectiveness of pretreatments and replacements with pretreated MSWIBA could be evaluated as suggestions for future engineering applications. The results are as follows, with 1% (by weight) BA addition to cement raw material, all samples with pretreated MDBA show higher compressive strength than samples with MDBA. It reveals that pretreatments have positive influence on burned material. Even though the BA addition percentage increased to 5%, samples could still meet CNS standard. But when the addition percentage rises up to 15%, the compressive strength of all samples drops dramatically. By crystal phase generation latency and LSF equations, it appears that when the BA addition percentage rises to more than 15%, the latency of C3S generation in clinker drops, and it is the major cause of decrease on the compressive strength of cement. To verify this inference, samples with 15% pretreated BA addition were tuned by substituting calcium oxide. All the tuned clinkers not only have strong strength on x-ray diffraction (XRD) spectrum but also have met CNS compressive strength criteria at 3 and 7 aging days. Therefore, pretreated MSWIBA with appropriate tuning is applicable to cement raw material replacement.
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Lo, Chen-Yu, and 羅振宇. "Study on Characteristics of Sintered MSWI Flyash with Microwave Digestion Treatment." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/wsf9z4.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
98
In all processing technologies for incineration flyash, the sintered processing is the most possible to turn incineration flyash into sources. However, the content of heavy metal and Dioxin in sintered MSWI flyash which generated in the sintering process is higher than incineration flyash by the evaporation of heavy metals and the synthesis of Dioxin in the sintered process. To understand the characteristics of sintered MSWI fly ash, so the object of this study is sintered MSWI flyash. This study explored the characteristics of sintered incineration flyash, and processed the sintered MSWI flyash by microwave digestion treatment (MDT). According to the results of experiments in this study, the sintered MSWI flyash was high alkaline substance. The average pH of sintered MSWI flyash was about 11.18. The water content of sintered MSWI flyash was about 5.12%. And the fixed carbon of sintered MSWI flyash was about 4.87. In chemical composition, CaO was the highest component of sintered MSWI flyash. The highest content of heavy metals in sintered MSWI flyash was lead, then zinc and copper. And the results of sintered MSWI flyash TCLP (toxicity characteristics leaching procedure) test showed that the highest heavy metal concentration was dissolved for lead than copper and zinc. When the MDT experimental conditions were 800 W, liquid-solid ratio 1/20, digested acids H2SO4 (8.9M) + HNO3 (7.8M), the efficiency of destroying Dioxin could reach 91.41%. The result showed that it was helpful to destroy Dioxin by MDT. Overall, when the concentration of acid increased, the weight-loss ratio of sintered MSWI flyash also increased. But whatever the concentration of acid was high or low, the weight-loss ratio of sintered MSWI fly ash was more than 91%.
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Yeh, Tai-liang, and 葉泰良. "Removal of Soluble Chlorinate by Acid Washing for MSWI Bottom Ash." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/j92u4j.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
99
Because of domestic incineration of concern, fly ash has become a follow-up question to be addressed. Bottom ash recycling products are mainly used in civil construction, road additires, it contains a high amount of water-soluble chloride ion will make the reuse restrictions before the incineration bottom ash uses again pretreatment for the bottom ash also appears important, and how does this research mainly increase the acidic medicament by four section of continuous-type washing in elimination bottom ash water-soluble chloride ion to meet domestic laws and regulations stipulations (The bottom ash the water-soluble chloride ion to be lower than 0.024wt% according to the CNS1240 before bottom ash reusing) as well as reduces the cost to favor in the project effectively the utilization. This research by liquid solid ratio、time、and the increase acidic medicament''s quantity takes experiment''s three tremendous influence condition, finally discovered that the fore-mentioned three conditions the enhancement can increases the efficiency with the bottom ash the water-soluble chloride ion in elimination, namely time = 10 minutes、liquid solid ratio =3, and the increase the acidic medicament are the acid: water , the bottom ash the water-soluble chloride ion density by 0.903% drop to 0.060% (to reduce the efficiency =93.36%); But when the condition enhances for time = 30 minutes、liquid solid ratio =3, the increase the acidic medicament is the acid: water =1: 100, the bottom ash the water-soluble chloride ion density drop to 0.020%, reduces the efficiency to reach as high as 97.75% and according to this study initially estimate cost of this work is 324 dollars each ton
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Ho, Chih-Chi, and 何志麒. "A Study on Recovery Treatment for MSWI Bottom Ash – Dechlorinate Performance." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4s6ye9.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
102
Currently the domestic incineration bottom ash reuse proportion elevates year after year, and the bottom ash resources to achieve the first type of EPA regulatory standards required to face the problem is high chloride content of bottom ash. This research focus on the chloride content in bottom ash. Investigate to increase the acidic medicament by washing in elimination bottom ash and reuse as feasibility of the first type of EPA regulatory.For removal efficiency of water-soluble chloride concentration. In addition to the retention time and liquid-solid ratio are the main factor, acid concentration is one of important factor. As acid concentration increases, effectiveness of the removal of chloride ions increases. By the experimental results showed that water-soluble chloride ion concentration for the removal efficiency, operating conditions for one in every 30 minutes retention time slot, liquid-solid ratio = 3, add the acid concentration is equivalent to the acid pH = 2.3, in four batches of test or continuous test Dosing washed, the residue at the end will enable the water-soluble chloride ion content of 0.893% from 0.020 %, achieve the first type of EPA regulatory standards, it can be used as gravel aggregate material in concrete applications, according to this study initially estimate cost of this work is 17,500 dollars / 500 ton, approximately 70 tons as gravel aggregates, the current price in the market is about 250 dollars each ton.Uunder equilibrium conditions,achieve the resource of MSWI Bottom ash as gravel aggregate material
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Chen, Cheng-Hung, and 陳政宏. "Preparation of Low Chlorine MSWI Bottom Ash Used As Secondary Materials." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/17920706189851192347.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系所
100
In Taiwan, the municipal solid waste are mainly treated by incineration and after the combustion residual bottom ash is a harmless waste, And it can be resued as natural aggregate. Coupled with these year the government to promote「zero waste, recycle」 policy. The bottom ash can be reused in many fields, but they have a serious problem that chloride ion in bottom ash is too high for using in reinforced concrete. Therefore,this paper tried to reuse the feasibility of the bottom ash, the bottom ash sub-screen using the hot water washing pre-treatment and with the electrolysis to comply with regulations and standards and the definition of a low-chlorine products for less than 100ppm. To explore the bottom before and after the residue washed chlorine balance analysis, the characteristics of the eluent and the sedimentation tank sludge leaching (wastewater sludge) utilization. The best chlorid removal percentage from bottom ash was found 95% by using solid-liquid 1:1.5, it is better than that of 1:06 and 1:1. If case of a combination using of electrolysis, the total removal percentage was near 97%. The goal for requsted low chlorine has been defined as 70 ppm. In the analysis of the chlorine balance, use the hot water for the error can reduced to 0.28% by using solid-liquid 1:1.5, eluent to explore the effluent standards for the number can be achieved with this. The wastewater sludge from bottom ash recycling plant is made into a drain cover, and is not broken after weighting test.
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Lin, Yu-Cheng, and 林育丞. "research the potential problem of MSWI bottom ash mixing with chment." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/55642657976881981910.
Full textAbstract:
碩士國立中央大學
土木工程研究所
91
Abtract The scope of this research are : (1) measure the basic properties of MSWI bottom ash; (2) study the solution to improve the expansion problem resulted from the gas production after mixing the bottom ash with cement; (3) investigate the methods to accelerate the setting time of bottom ash contained mortar due to the retardation of cement hydration induced from the organic matter in the ash. Test results show that the generation of hydrogen resulted from the reaction of the aluminum contained in the bottom ash with alkaline or acidic solution might be the source of gas production to induce mortar expansion. Spray sodium hydroxide or phosphoric acid on the bottom ash could reduce the gas production. However, immerse the bottom ash in sodium hydroxide or phosphoric acid solution would abtain better efficiency of gas reduction. Both reincinerate the bottom ash and washing the bottom ash by sodium hydroxide solution could accelerate the setting time and inicrease the strength development of the mortar contained ash due to the reduction of organic matter in the ash. Keywords: Bottom ash; expansion; Reincineration
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Liu, Hung-en, and 劉鴻恩. "Effect of Heavy Metals and MSWI Ashes on OFMSW Biodegradation by Earthworms." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/54762477255891887485.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
97
Earthworms have been used to assess the toxicity of heavy metals on the biological effects, such as cadmium, zinc, copper, chromium and nickel. The main purpose of this study was to add in the use of heavy metals and ash (bottom ash and fly ash) on earthworms affect decomposition of organic waste. Based on the results of this study, the conclusions obtained are as follows: 1. Earthworm growth and reproduction and diet are closely related to the pH value, add the heavy metals Cd, Cr, caused by decreased pH, earthworms do not like to become a living environment. 2.In addition the body of heavy metals in earthworms, there is obviously the case of accumulation of earthworms on the accumulation of heavy metals to the highest cadmium. Heavy metal concentration of 10 mg kg-1, earthworms have a high survival rate. And with increasing external concentration of heavy metals accumulated body concentration, the survival rate is also a downward trend, in which the concentration of earthworms on Zn tolerance, the highest survival rate.
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黃沐域. "Study of thermally immobilized Cu-contaminated soil mixing with MSWI fly ashes." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/57484502322443466469.
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Chen, Yu-Lun, and 陳佑倫. "The Study of the MSWI fly ash Recovery as a Cement Substitute." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/s42cq7.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
95
The major constituents of the MSWI fly ash are calcium, silicon, aluminum and iron etc; they are almost the same as the feedstock of cement. The MSWI fly ash recovery as a cement substitute not only to solve the cement raw materials using but also conform to the concept of sustainable use. In this study four aspects were discussed: (1) comprehend the characteristic of MSWI fly ash; (2)confer the influence of the parameters of hydration to milling fly ash replace cement; (3)confer the mechanism of the reaction of pozzolanic of milling fly ash replace cement; (4) confer the influence of leaching of heavy metal. The results indicated that：(1) The compressive strength of adding milling 96hr fly ash cement is higher than adding milling 0hr fly ash cement and ordinary portland cement of any W/C and age. (2) The TCLP leaching concentrations for the heavy metals (Cd, Pb, Zn, Cr, Cu) were all well below the regulatory thresholds. (3) The hole of adding milling fly ash is <0.01μm account compressive strength develop fast.(4) The C-S-H of adding milling fly ash is shorter than ordinary portland cement account have closeness space.
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Lin, Pei-Ying, and 林佩瑩. "A Study on Effects of MSWI Bottom Ash Properties after Accelerated Carbonation." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/7hj6wg.
Full textAbstract:
碩士國立臺北科技大學
資源工程研究所
99
In this study, the effects of accelerated carbonation on the chemical properties, mineral morphologies and microstructures of Bottom ash under various accelerated carbonation parameters are evaluated. Under optimum accelerated carbonation parameters, the results indicate that particle size 0.5 to 4.75mm and 0.5 to 25.4mm of Bottom ashs individually lowered their pH values from 12.29 and 10.87 to 10.88 and 9.87. The XRD patterns of accelerated carbonation Bottom ashs show that there were calcite on the surface of Bottom ash and the spectra of FTIR of accelerated carbonation Bottom ashs indicate that there were CO32- function groups presenting on surface of carbonated accelerated carbonation Bottom ashs. Other Water-soluble chloride ion dissolved a large decline with CO2 content increased. Therefore that accelerated carbonation can actually reduce Bottom ash leaching of water-soluble chloride ion. The results in accordance with TCLP and Column Leaching Test indicate that the leaching concentration of Cu, Pb, Zn in accelerated carbonation Bottom ash was obviously decreased. Further uses the MINTEQA2 software simulation of the dissolution behavior of heavy metal. By the simulation results show the dissolution of Ca had a large decrease at high pH (pH> 10), The Ca of the dissolution at pH 4-8, its dissolution behavior to gypsum. When the pH at 4-8, its dissolution behavior to calcite. Al, Ca and SO4 dissolves behavior to gibbsite (Al(OH)3(s))、gypsum (CaSO4 ．2H2O) and ettringite (Ca6Al2(SO4)3(OH)12 ‧26H2O(s)). Based on the above results, accelerated carbonation of Bottom ash not only reduces high alkalinity of Bottom ash and leachability of heavy metals in Bottom ash, but also promotes the utilization of Bottom ash and reaches the reduction of carbon dioxide.
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Lai, Chun-Wei, and 賴俊瑋. "Reduction of Chloride and Lead Metal in MSWI Fly ash recycling technology." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/7wud4u.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
100
MSWI fly ash reutilitation is an issue of concern in the world. Because landfill disposal or thermal malting treatment does not meeting the reguirement of low GHG and energy-saving. The thermal degradation with salting precipitation studied in this work will be a promising technology to reduce Pb-metal and chloride in the MSWI fly ash. According to this study, it shows that the reduction of hazardous substances from Fly ash and the content of Chlorine ： 1. After direct heating of the acid solution and salting processing, main chemical properties of fly ash has been significantly changed, such as SiO2 by 23.21wt % reduced 20.38 wt % , Fe2O3from 2.05wt % to 0.74wt % , Al2O3 from 4.70wt % to 1.86wt % , CaO from 25.95wt % to 8.34wt % , this substances probably formation the other hydroxide or loss in acid. 2. Found by experimental results, Pb-TCLP Reduction effectiveness between 63%~74%, the content of Chlorine Reduction effectiveness between 15%~45%, If TCLP value of the original fly ash under controlled 40mg / L, it can deal with regulation states 5mg / L
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Chen, Jian-Syun, and 陳建勳. "A Feasibility Study on Concrete Aggregate Replacement Material for MSWI Bottom Ash." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/nt67c9.
Full textAbstract:
碩士國立臺北科技大學
環境規劃與管理研究所
102
The re-utilization rate of municipal solid waste incineration bottom ash is increasing gradually in recent years, so as to reduce use rate of landfill site and prolong its life. Application of recycle is becoming wider and wider, which is mainly used for asphalt concrete and non-reinforced concrete replacing aggregate, so as to add domestic aggregate sources.This study aims at pretreatment and final treatment of bottom ash. In the bottom ash treated by aggregate screening (particle size, soundness and abrasion test), it is known that the bottom ash capable of being for subsequent elaboration processing accounts for about 62.4%, wherein coarse aggregate accounts for about 19.4%, fine aggregate accounts for about 43.0%, loss rate of soundness test aggregate is about 5%, coarse granular material accounts for about 8%, abrasion rate is about 40%, which all confirm to the specification of concrete aggregate. Furthermore, it uses a single tank four-time continuous method to conduct experiments respectively by different acid concentration, detention time and liquid-solid ratio. According to experimental results, under the best conditions that liquid-solid ratio is 3, single tank detention time is 30 minutes, added acid concentration pH is 2.40 (acid/water=0.01), water-soluble chloride ion concentration decrease from 0.893% (original bottom ash) to 0.020% (≦0.024%), which conforms to first category of recycle standard in domestic regulations and is able to make odor concentration index decreased from 1,000 to 10. Through comprehensive analysis, preliminary screening, fine separation and washing by acid liquid, it can really make bottom ash comply with first category of code standard and apply to replacing part of aggregate. If the cost for dealing with 500 (ton/day) bottom ash is about 35 TWD/ton and processed valuable products capable of replacing aggregate are about 70 tons, the overall processing cost benefit can reach balance between profit and loss based on the current market price of aggregate (250 TWD/ton in conservative estimate).
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Chan, Jia-Kai, and 詹家凱. "A Study on Dechlorinate of MSWI Bottom Ash by Reagent-Assisted Washing." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/pavq4p.
Full textAbstract:
碩士國立臺北科技大學
環境規劃與管理研究所
102
Domestic incinerator bottom ash recycling since 2003 to promote, in recent years, the domestic provisions for bottom ash recycling and reuse are increasingly stringent, bottom ash recycling based on different quality standards can be divided into three types, but most of the domestic processing vendor only conform to the provisions of the second type of re-use, resulting in bottom ash recycling purposes limited to provenance bottlenecks, Which, in order to reach the first type provides, One of the biggest problems facing the still required at the end of the water-soluble chloride content of the bottom ash, the study expected by way of reducing the washing of water soluble chloride content of bottom ash, reaching dechlorination of Objective, in order to enhance the level of re-use or re-utilization, and cost-effectiveness of the real plant be considered. In the study, liquid-solid ratio, residence time, and concentration of added acid lotion as a test of the three operating conditions, the study found the aforementioned operating parameters to improve the water-soluble chloride ions with a positive correlation between the reduction efficiency. According to the test results of the analysis showed that each wash tank using different operating parameters, Its best operating conditions for the retention time of 30min first slot, liquid-solid ratio = 3, add the acid concentration is equivalent to the acid pH =2.3, the second groove to Single residence time 30min , liquid-solid ratio = 3, add the acid concentration is equivalent to the acid pH = 2.9, the third slot to Single residence time 10min, liquid-solid ratio = 1, add the acid concentration is equivalent to the acid pH =2.3, the fourth slot to Single residence time 30min, liquid-solid ratio = 2, add the acid concentration is equivalent to the acid pH = 2.9, its water-soluble chloride was reduced rate of 98.74%; Another research results to practical engineering planning, such as the use of different operating conditions, costs about 489 dollar/ ton.
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Liu, Chen-Yi, and 劉真驛. "Developing Advanced Processes for Detoxification and Chloride Minimization of MSWI Fly Ash." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/73403370671472721992.
Full textAbstract:
碩士國立聯合大學
環境與安全衛生工程學系碩士班
103
Four municipal solid waste incineration (MSWI) fly ashes (M, N, Z, and H) were treated by existed and advanced technologies to explore each performance and conclude an optimal process in which both of detoxification (TCLP-heavy metals below regulatory limits) and chloride minimization (water-soluble chloride < 1.00%) targets for the treated MSWI fly ash could be obtained. N and Z fly ashes were treated by the existed technologies (water extraction and CO2 stripping & carbonation). The results show that both fly ashes can pass TCLP-heavy metal regulatory limits after low L/S water extraction process. In the next process of CO2 stripping & carbonation, CO2 stripping can easily form CO32− and further associate with heavy metals (e.g., PbCO3, CdCO3). Thus, most of heavy metals in fly ash were stabilized; nevertheless, some heavy metals were dissolved by the acidification of carbonation. Advanced technologies (grinding, classifying into different particle size group, submerged aging, and intermittent shaking) were applied to M fly ash. The results indicate that the leaching of both heavy metal and chloride increased with the reduction of fly ash particle size. The release of chloride and heavy metal in submerged aging was higher than that of natural dry aging. Therefore, grinding fly ash and submerged aging with intermittent shaking (i.e., enhanced aging) were selected as two of the advanced technologies. The results of advanced process including grinding and enhanced aging show that TCLP-Pb was below regulatory limit and water-soluble chloride was 0.36%. Another result of advanced process including grinding, advanced aging and stripping, called optimal process, reveals that TCLP-Pb detections were ND and 3.38 mg/L for CO2 and air stripping respectively, and water-soluble chloride was the same (0.71%). The removals of heavy metals and water-soluble chloride could be found in filtrate of each step. Finally, H fly ash was selected for verifying the feasibility of optimal process and the results show that both of TCLP-Pb below regulatory limit and water-soluble chloride < 1.00 % met the research goal.
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Huang, Tai-Yuan, and 黃泰元. "Analysis of MSWI Fly Ash Reuse in Property and Life Cycle Assessment." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/43771893706453919194.
Full textAbstract:
碩士國立臺灣大學
環境工程學研究所
103
As global population has increased, the generation of municipal solid waste has also increased and its treatment is a salient issue for many governments. Fly ash is a byproduct of solid waste incineration and is regarded as hazardous waste. Yet fly ash can be reused in cement, bricks, alkaline, aggregate sand other treatments. However, these fly ash reuse treatments might create higher environmental impacts. Therefore, the study aims to discuss the most common fly ash reuse and treatments and evaluate them by environmental impact and cost benefit analysis, to choose the better fly ash reuse treatment alternatives. This research discusses four kinds of fly ash treatments scenarios: 1) Landfill after solidification, 2) Reuse as cement, 3) Reuse as bricks, 4) Reuse as alkaline in Waelz process, and evaluates each in two parts. The first part experimental, which analyzed heavy metal composition before and after washing process. The second part is to evaluate fly ash reuse treatment by life cycle assessment. Inventory data were obtained from commercial operation factories and references, and LCA software SimaPro and environmental impact model IMPACT 2002+ were used to evaluate the outcome of LCA. It was found that although washed fly ash can stabilize toxic substances, it also can increase heavy metal concentration, In LCA portion, the highest impact scenario is scenario 2, second is scenario 1, third is scenario 3, the lowest impact is reusing as alkaline of the low impact of scenario 4 is due to the benefit from recycling zinc. Fly ash reuse treatment will be increasingly important and will require many considerations. In terms of environmental impact, this research aims to provide a holistic comparison between different fly ash reuse treatments to further recommendation of better fly ash reuse treatment.
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Ho, Yu Chen, and 何宇程. "Preparation of Eco-composites from MSWI Ash Wastes through Physical Stabilization Process." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/02827667342174343036.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系所
100
In responding to the zero-waste policy, the incineration treatment of municipal solid wastes has become an important issue; therefore, we hope to handle incineration ash wastes effectively in order to achieve zero-waste emissions. Heavy metals and other chlorinated organics are generated from the municipal solid wastes incineration process and they are part of the so called fly ashes, they are usually recognized as hazardous industrial wastes through the Toxicity Characteristic Leaching Procedure (TCLP) test. However, the present treatment of incineration fly ash by means of the solidification/stabilization process, the washing process to remove chloride prior to make cement and lightweight aggregate or to make environmental cement by the high-temperature sintering. These processes have several disadvantages of high technical level required, high initial set-up cost, operations and maintenance costs. The goal of international trends is to efficiently improve the recycling of the ash wastes. In order to break through the incineration fly ash, unable reused, what is one of the hazardous industrial wastes. In this study, the samples collected from two large incinerators in the southern part of Taiwan included unhandled semi-dry scrubber ash, heat-saving devices ash, super-heaters ash, boiler ash, bottom ash and treatment sediment ash, we used the physical treatment to treat the incineration ash wastes, to effectively decrease the concentration of heavy metals in order to fully fit the regulation levles of TCLP standards. Furthermore, our developed method also achieves the goals of low cost and high engineering feasibility. The results showed that the particle size of ash wastes were sieved over than 0.074 mm and mixed sample together. When the mixing ratio was controlled fewer than 33%, the indicators of the extracted concentrations of Pb, Cu, Cr, Cd, Ba and Se could be effectively reduced to less than TCLP regulatory standards. Therefore, MSWI ash wastes could be considered of reuse purposes.
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SU, YI-JU, and 蘇薏茹. "Developing advanced treatment and glass-materialization technologies for recycling MSWI fly ash." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/56965741621226187280.
Full textAbstract:
碩士國立聯合大學
環境與安全衛生工程學系碩士班
104
For developing non-Muzha municipal solid waste incineration (MSWI) fly ashes with the possibility of no more cement solidification/landfill treatment and increasing the value of reuse products, two similar M and H MSWI fly ashes (high Cl– content of 20.1–23.6% and TCLP-Pb of 10.30–11.12 mg/L, exceeding regulatory limit) were studied in the following two parts: (1) Detoxification of fly ash: detoxification by multi-treatment technologies and minimizing fly ash Cl– content < 1% using M fly ash. (2) Producing valuable fly ash products: fly ash mixed with some materials and firing at different temperature to produce inedible normal and lead-containing glasses using H fly ash. The results of detoxification of M fly ash showed that TCLP-heavy metals past the regulatory limits and Cl– content reduced to 0.36% at the operation conditions of low L/S (1.2 and 2), 2 days aging and 0.1 M H2SO4 treatment. The best treatment process was water extraction + 2 days aging + acid stabilization combined with aging, which not only shortened the processing time but also met the detoxification goal; furthermore, fly ash Cl– content was only 0.35% (< 1%) and Cl– removal in solid phase was 99.39% (liquid phase removal was 73.23%). The best production of inedible normal glass made from fly ash was R-9 (materials were 29% original fly ash +29% Na2CO3 + 42%SiO2 + 1% activated carbon, firing at 1,300 °C for 1 hr). Glass analysis of Na-Ca-Si structure, no porosity, and Cd and Pb below leaching regulatory limits were observed; moreover, density and refractive index were 2.67 g/cm3 and 1.561 respectively, better than that of market sold normal glass. In the best production of inedible lead-containing glass made from fly ash sludge was P-2 (materials were 26% fly ash extracted sludge +26% K2CO3 + 48%SiO2, firing at 1,300 °C for 1 hr). Glass analysis of K2O-PbO-SiO2 structure, no porosity, Cd below leaching regulatory limit, but Pb leaching of 12.50 mg/dm2 were observed; additionally, density and refractive index were 2.77 g/cm3 and 1.566 respectively, better than that of R-9 glass. All of the results can be further provided for non-Muzha MSWI plants in the fly ash detoxification and resources recovery.
48
Huang, Cheng-Lung, and 黃政隆. "A Study on the Stabilization of MSWI Bottom ash by Soaking Carbonation." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/65513820447448787610.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
102
Municipal solid waste incinerator (MSWI) bottom ash should be pretreated before reusing, which can reduce the risk of polluting the environment by leaching the heavy metals from bottom ash. It is significant scientific and engineering benefit of carbonization for stabilization of solid waste. Nevertheless, taking too much time is the defect of the carbonization. In this study, the retrieved water of washing bottom ash aerated carbon dioxide about 10% to become carbonated water. Let calcium from bottom ash and carbonate ion from carbonated water reacted to form calcium carbonate by dipping process to raise the stability rate of heavy metals. The experiment of this study has divided into two parts of batch and circulation. In the batch experiment, the bottom ash through two steps of five minutes stirred and then dipped in carbonated water for 3, 6 and 18h. The aim of this experiment is to observe the concentrations of TCLP for heavy metals and the remove rate of chlorine ion. In the circulation experiment, the dripped solution would be recycled to substitute the tap-water of the first step wash water. The bottom ash through two steps of five minutes stirred and then dipped in carbonated water for 0.5, 1 and 3h. In a circle, the process needs to repeat three times. The result of the batch experiment shows that the dripping process really can reduce the TCLP concentration of heavy metals. The concentrations of lead and cadmium do not decrease with the dripping time. Zinc and copper would increase the leaching rate with the dripping time increased. The leaching rates of the water-soluble chloride ion were 44.2%, 45.2% and 46.3% at dipping time of 3, 6 and 18 h respectively. The consummation of alkalinity in the water increases with the dripping time. The results of the circulation experiment indicate that the leaching concentration of Pb, Zn, Cu and Cd were 0.02, 8.23, 1.49 and 0.09 mg/L and would be restrained after dripping time of o.5h. Specially, the Cr concentration was not detectable. The leaching amount of the water-soluble chloride increased with the dripping time increased. The leaching rates were 74.3%, 76.2% and 85.7% after dripping time of o.5, 1 and 3h respectively. The dripping time of 0.5h and dry in 105 oC of oven could reach the aim of stabilization of heavy metals and increase the leaching rate of chloride.
49
林宜臻, Yi-Chen Lin, and 林宜臻. "An In-situ Case Stdy on Optimal Fixation Conditions for MSWI Fly Ash." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/eb7r64.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
101
Main strategy of waste treatment in Taiwan is combustion. Due to space for disposal is limited and hard to obtain, it is difficult to deal with such large amount of ash disposal. We proceeded this research for seeking efficient method of fly ash treatment in order to reduce pollution and environmental loading. In this research, we talk about relation between operating factors of solidification/ stabilization and lead leaching. We estimate best operating factors of minimizing lead leaching by determine the physical and chemical composition of fly ash, operating factors of solidification/stabilization (inclusive of weight of chelating agent, weight of cement, and stirring time), and the amount of lead leaching after solidification/ stabilization. The results show that different operating factors results in variation of TCLP. Furthermore, we find best operating ratio to make process stable, restrain lead leaching, and reduce amount of waste to extend life of landfill field. The best operating factors of solidification/stabilization are weight ratio of chelating agent: 3.19%, weight ratio of cement: 6.99%, and stirring time: 75 seconds. We find that under those operating factors, there is 99.58% reduction efficiency of lead leaching. It also demonstrates that as we adopt such factors in solidification/stabilization, we will reduce leaching and bad impact to our environment. It can be applied to real operation in the future.
50
Shen, Y.-Ming, and 沈奕銘. "A Feasibility Study on Cement Replacement Material for Non-Hazardous MSWI Fly Ash." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/ywvesy.
Full textAbstract:
碩士國立臺北科技大學
環境工程與管理研究所
101
The object of this thesis is to study destroying the hazardous and toxic of fly ash to obtain the non-hazardous fly ash, and to explore the properties of the MSWI fly ash slag to evaluate the feasibility of its reuse as a substitute for part of the cement required by thermal degradation with salting precipitation. The results obtained from this study indicate that thermal degradation pretreatment will reduce SiO2 from 25.97% to 18.77 %, Fe2O3 from 5.03% to 2.65 %, Al2O3 from 3.64% to 3.01 %, CaO from 26.46 % to 17.44 %, and the lead TCLP reduction rate of about 74 percent to 89 %, and the chloride reduction rate of about 15% to 45%, and the dioxin content to be reduced from 2.110 down to 0.055 (ng I-TEQ / g ‧ dw), the reduction efficiency of PCDDs/Fs could reach 98%. Fly ash reuse as a substitute for part of the cement matrix to improve its fluidity performance, including: (1) The fluidity value of fly ash slag substitution increases with a higher W/C ratio, and increases with the substitution percentages. (2) Setting time with an fly ash substitution increases. (3) When the W/C = 0.37 and the curing age = 28 days, with a 5% cement-replacement , the Fly Ash-Cement Paste(FC) compressive strength was similar to Ordinary Portland Cement Paste(OPC), and when the 10% cement-replacement at the age of 28 days, the compressive strength was higher than OPC, therefore when FC under the conditions of low cement-replacement(5% or 10%) there will having greater compressive strength than that without the substitution. Changes in the physical and chemical properties can be used as engineering of reference.