Journal articles: 'Ozone removal'

1

Chang, T. C., Y. W. Pan, S. S. Chen, and C. K. Chen. "Removal of natural organic matter (NOM) using ozonation and ultrafiltration." Water Supply 1, no. 5-6 (June 1, 2001): 49–54. http://dx.doi.org/10.2166/ws.2001.0099.

Full text

Abstract:

Pilot studies were conducted at Liu-Du water treatment located in Keelung, Taiwan. Raw water was first treated by conventional coagulation- sedimentation-filtration (CSF) processes, and then pumped into the pilot plants. For the pilot plants, both ozone/GAC and ozone/UF processes were operated simultaneously for NOM removal comparisons. Both systems were controlled at the same operating conditions with ozone dosing of 4.5, 6.0 and 9.0 mg/L. The results demonstrate that both ozone/UF and ozone/GAC processes can enhance NOM removal after the CSF process. More NOM was removed by the Ozone/GAC process because ozone broke the large molecules into smaller molecules, which increases the GAC adsorption potential. However, the ozone/UF process provides higher removal capacity in turbidity. In both processes, ozone dosing was not proportional to NOM removal of each process and 6.0 mg/L is found to be the optimal dosing. Owing to increasing adsorbability by ozonation, the ozone/GAC process is a very competitive process in NOM removal when associated with the CSF process.

APA, Harvard, Vancouver, ISO, and other styles

2

Kye, Homin, Heegun Oh, Youmi Jung, Minhwan Kwon, Yeojoon Yoon, Joon-Wun Kang, and Tae-Mun Hwang. "Oxidation of Florfenicol and Oxolinic Acid in Seawater by Ozonation." Applied Sciences 10, no. 14 (July 18, 2020): 4944. http://dx.doi.org/10.3390/app10144944.

Full text

Abstract:

There has been an increase in the use of antibiotics by the aquaculture industry in marine aquaculture for the prevention of diseases in fish. Antibiotics in the water discharged into the sea without treatment can cause disturbances to the marine ecosystem. Therefore, there is a need for research on how the removal of antibiotics used in aquaculture can be achieved. In this study, the removal of two types of antibiotics (florfenicol, FF, and oxolinic acid, OA) used in the aquaculture industry, by ozonation, was evaluated. Currently, there is a lack of research studies on FF and OA removal from seawater by ozonation. Seawater ozonation shows a significantly different oxidation mechanism as compared to that of freshwater. The high amount of Br− in seawater (60 mg/L) allows for a rapid reaction with ozone to produce bromine (HOBr/OBr−) at a rate of 160 M−1s−1. To predict the removal efficiency of antibiotics by ozone and bromine, the species-specific rate constants for the reaction of FF and OA with ozone and bromine were determined. The predicted removal efficiencies of FF and OA using measured rate constants were verified by the ozonation process in water containing bromide ions in similar concentrations as in seawater. The result for FF indicated less than 10% removal during 20 min, with the rate constants of FF with ozone and bromine being 3.2 M−1s−1 and 3.5 M−1s−1, respectively. However, the removal of OA using ozonation was approximately 99% or higher within 90 s. In the presence of bromide ions, approximately 60% of OA was removed by trace ozone within 15 s, and approximately 30% of OA was removed by the generated bromine after 15 s. Comparing the removability of FF and OA used in aquaculture by ozone, it was observed that FF was more difficult to remove because of its low reaction rate constant. Meanwhile, the reaction rates of OA with ozone and bromine were 2.4 × 103 M−1s−1 and 4.0 × 102 M−1s−1, respectively. At the beginning of the reaction, OA was removed by the trace ozone. Subsequently, OA was removed by the generated bromine after the ozone was decomposed.

APA, Harvard, Vancouver, ISO, and other styles

3

Riadi, Lieke, Ali Altway, Sasmita Mirifica Vania, and Andy Widyasayogo. "Study on kinetic parameter in real yarn dyed wastewater treatment using electrocoagulation-ozonation process." Water Practice and Technology 12, no. 3 (August 1, 2017): 690–97. http://dx.doi.org/10.2166/wpt.2017.073.

Full text

Abstract:

Treatment of real yarn dyed wastewater using hybrid electrocoagulation (EC)-ozonation process has been carried out to solve the non biodegradable wastewater. The work aimed to treat the real yarn dyed wastewater under different ozone concentration and agitation speed and to estimate the kinetic parameter of ozonation. The effect of ozone concentration, agitation speed were studied to give the best performance of color and chemical oxygen demand (COD) removal. The result indicated 38.12% of COD removal and 92.53% of color removal using EC with Al/Al electrodes for 10 minutes. The effluent was pumped to ozonation process for further COD removal. The result showed that 1 mg/L ozon was needed to destroy 4.73 mg/L COD. At ozonation process, the COD removal was 87.4% using 5.8% mol ozone at 400 rpm for 60 minutes. The kinetic parameter was estimated based on the experimental data. The reaction rate constant was 173.5 cm3/(g sec).

APA, Harvard, Vancouver, ISO, and other styles

4

Wu, Fan, Yuanwei Lu, Mingyuan Wang, Xingyuan Zhang, and Chunxin Yang. "Catalytic Removal of Ozone by Pd/ACFs and Optimal Design of Ozone Converter for Air Purification in Aircraft Cabin." Civil Engineering Journal 5, no. 8 (August 21, 2019): 1656–71. http://dx.doi.org/10.28991/cej-2019-03091361.

Full text

Abstract:

Ozone in aircraft cabin can bring obvious adverse impact on indoor air quality and occupant health. The objective of this study is to experimentally explore the ozone removal performance of flat-type catalyst film by loading nanometer palladium on the activated carbon fibers (Pd/ACFs), and optimize the configuration of ozone converter to make it meet the design requirements. A one-through ozone removal unit with three different Pd/ACFs space was used to test the ozone removal performance and the flow resistance characteristic under various temperature and flow velocity. The results show that the ozone removal rate of the ozone removal unit with the Pd/ACFs space of 1.5 mm can reach 99% and the maximum pressure drop is only 1.9 kPa at the reaction temperature of 200℃. The relationship between pressure drop and flow velocity in the ozone removal unit has a good fit to the Darcy-Forchheimer model. An ozone converter with flat-type reactor was designed and processed based on the one-through ozone removal experiment, its ozone removal rate and maximum pressure drop were 97% and 7.51 kPa, separately, with the condition of 150℃ and 10.63 m/s. It can meet the design requirements of ozone converter for air purification and develop a healthier aircraft cabin environment.

APA, Harvard, Vancouver, ISO, and other styles

5

Zhao, P., J. A. Siegel, and R. L. Corsi. "Ozone removal by HVAC filters." Atmospheric Environment 41, no. 15 (May 2007): 3151–60. http://dx.doi.org/10.1016/j.atmosenv.2006.06.059.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Su, Jia Quan, Yi-Chun Chang, and Jeffrey C. S. Wu. "Visible-Light Photocatalyst to Remove Indoor Ozone under Ambient Condition." Catalysts 11, no. 3 (March 16, 2021): 383. http://dx.doi.org/10.3390/catal11030383.

Full text

Abstract:

Ozone is a kind of hazardous gas in indoor areas and needs to be removed in order to protect the human respiratory system. Previous methods include physical adsorption, thermal treatment, electromagnetic radiation removal, catalysis and photocatalysis. However, they all have limited effects. This research introduced a novel milestone to remove indoor ozone by utilizing visible light photocatalysis technique under ambient condition. The modified sol–gel method was applied to prepare photocatalysts, strontium titanate (SrTiO3) and rhodium-doped strontium titanate (SrTiO3:Rh). In addition, the SrTiO3:Rh was further immersed in N3 dye to improve its photocatalytic performance. Batch system and continuous-flow system were used to quantify the removal rate of ozone and to measure the conversions of ozone, respectively. The results showed that SrTiO3:Rh possessed a higher ozone removal rate under a visible light condition compared with a commercial P25 TiO2 catalyst. In addition, SrTiO3:Rh based catalysts can also successfully perform visible light ozone photodecomposition in the continuous ozone flow system. Note that current ozone converters in aircraft utilize thermal-catalysts, which can only be operated at high temperature. This research reveals a promising catalysts and photo process, which can possibly replace the current aircraft ozone converters with visible-light driven converters, and boast higher performance under ambient condition.

APA, Harvard, Vancouver, ISO, and other styles

7

Wang, Jian, Cong Du, Feng Qian, Yonghui Song, and Liancheng Xiang. "Enhanced Treatment of Pharmaceutical Wastewater by an Improved A2/O Process with Ozone Mixed Municipal Wastewater." Water 12, no. 10 (October 5, 2020): 2771. http://dx.doi.org/10.3390/w12102771.

Full text

Abstract:

A pilot-scale experiment is carried out for treating mixed wastewater containing pharmaceutical wastewater (PW) and domestic wastewater (DW), by a process that is a combination of hydrolysis acidification-ozone-modified anaerobic–anoxic–aerobic-ozone (A2/O) (pre-ozone) or hydrolysis acidification-modified A2/O-ozone (post-ozone). The effects of different mixing ratios of PW and DW and pre-ozone treatment or post-ozone treatment on the removal of nitrogen and phosphorus and chemical oxygen demand (COD) are compared and studied. The optimal ratio of PW in mixing wastewater is 30%, which has the optimal COD removal efficiency and minimum biotoxicity to biological treatment. The pre-ozone treatment shows more advantages in removing nitrogen and phosphate but the post-ozone treatment shows more advantages in COD removal. Analysis of dissolved organic matter (DOM) demonstrates that post-ozone treatment has a more significant effect on the removal of fulvic acid and humic acid than the effect from the pre-ozone treatment, so the COD removal is better. Overall DOM degradation efficiency by post-ozone treatment is 55%, which is much higher than the pre-ozone treatment efficiency of 38%. Microbial community analysis reveals that the genus Thauera and the genus Parasegetibacter take great responsibility for the degradation of phenolics in this process. All the results show that the post-ozone treatment is more efficient for the mixed wastewater treatment in refractory organics removal.

APA, Harvard, Vancouver, ISO, and other styles

8

Orhon, D., H. Dulkadiroğlu, S. Doğruel, I. Kabdaşli, S. Sozen, and F. Germirli Babuna. "Ozonation application in activated sludge systems for a textile mill effluent." Water Science and Technology 45, no. 12 (June 1, 2002): 305–13. http://dx.doi.org/10.2166/wst.2002.0439.

Full text

Abstract:

The study investigates the effect of partial ozonation of textile wastewater, both at the inlet (pre-ozonation) and the outlet (post-ozonation) of biological treatment, for the optimization of COD and color removals, both typical polluting parameters associated with the textile industry. Pre-ozonation provides at optimum contact time of 15 minutes 85% color removal, but only 19% COD reduction. Removal of the soluble inert COD fraction remains at 7%, indicating selective preference of ozone for simpler compounds. Post-ozonation is much more effective on the breakdown of refractory organic compounds and on color removal efficiency. Ozonation after biological treatment results in almost complete color removal and a 14% soluble inert COD reduction. The polishing effect of post-ozonation also proves quite attractive from an economical standpoint, involving approximately 50% of the ozone utilization at the same ozone flux rate and contact time, yet providing a lower soluble residual COD level.

APA, Harvard, Vancouver, ISO, and other styles

9

Tang, Xiao Bin, Jian Feng Zou, Kai Fan He, Jian Liu, Jian Jun Zhou, Fu Jin Wang, Yi Xing Yuan, and Jun Guo He. "Research on the Treatment of the Yellow River Micro-Polluted Water in Shanxi by Ozone-Activated Carbon Process." Advanced Materials Research 989-994 (July 2014): 803–8. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.803.

Full text

Abstract:

In this study, the micro-polluted water of a reservoir filled with Yellow River water in Shanxi was used as the raw water. The removals of chemical oxygen demand (CODMn), ammonia nitrogen, petroleum substances, and volatile phenol were investigated by ozone-activated carbon process. Results showed that ozone-activated carbon process had a good removal of the pollutants mentioned above. The optimum dosage of ozone for each pollutant was 2.0 mg/L, 2.5 mg/L, 3.0 mg/L, 3.0mg/L, with the corresponding removal efficiency of 59.36 %, 88.01%, 79.31%, and 88.16%, respectively. The treated water quality could meet the standards for Drinking Water Quality (GB5749-2006) in China.

APA, Harvard, Vancouver, ISO, and other styles

10

Lee, Byoung-Ho, Won-Chul Song, Jong-Gyu Ha, Hyeon-Ju Yang, and Young-Suk Kim. "Effects of ozone in treating drinking water by DAF system." Water Supply 9, no. 3 (August 1, 2009): 247–52. http://dx.doi.org/10.2166/ws.2009.320.

Full text

Abstract:

The Dissolved Air Flotation (DAF) process is very effective in removing low density floc particles for drinking water treatment. It is especially well known in removing turbidity and algae by flotation process. The micro-bubbles in the DAF process pick up small flocs, thereby turbidity materials and floated algae are removed efficiently. When air is substituted by ozone in the DAF process, the removal rates of water quality parameters are highly enhanced including turbidity and algae. The turbidity removal rate is enhanced by 1.1% while the removal rate of THMFP is increased by 11.7%. Other parameters such as TOC, and microbial agents are also removed greatly by using ozone instead of air in DAF system.

APA, Harvard, Vancouver, ISO, and other styles

11

Xiang, Ying Hong, Yang Yang Zhong, Xiang Dong Li, and Jun Ke Song. "Treatment of Organic Compounds in Radioactive Wastewater by Ozonation." Advanced Materials Research 726-731 (August 2013): 2604–8. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.2604.

Full text

Abstract:

The organic compounds in radioactive wastewater were treated using ozone oxidation technology. The influence of pH, ozone dosage, reaction time, initial COD, H2O2 on the removal of COD by ozone was investigated. The results showed that the removal efficiency of COD in the alkaline condition was higher than that of acidic condition, the COD removal rate increased with increasing ozone dosage, reaction time, H2O2 dosage, decreased with increasing initial COD. Under the conditions of COD 362 mg/L, pH value 9.0, ozone dosage 7.86 mg•L-1•min-1, reaction time 30 min , the removal rate of COD was 25.9%; the removal rate of COD increased to 37.8% when 0.2 ml H2O2 was added in addition.

APA, Harvard, Vancouver, ISO, and other styles

12

Lee, C. W., H. K. Yeom, S. W. Yoo, and L. S. Kang. "A study on the efficiency of the DAF (dissolved air flotation) process using ozone injection." Water Supply 9, no. 2 (June 1, 2009): 107–11. http://dx.doi.org/10.2166/ws.2009.238.

Full text

Abstract:

In this study, dissolved ozone flotation system with injecting ozone directly into a DAF pump developed was applied to remove turbidity and organic matter for water treatment. This ozone flotation system was evaluated on the basis of the efficiency of ozone transfer into water and the removal efficiency of turbidity and TOC in the Nakdong river water. The DAF pump system found to be more efficient than the conventional DAF system injecting ozone directly from a ozone generator. The ozone through the DAF pump process was dissolved in water much faster than through the general ozone generator due to the higher mixing efficiency through a pump impeller and high pressure inside the DAF pump. Also, the kinetics of ozone decay injected by the DAF pump was slower than injected by an ozone generator. The DAF pump flotation system shows that 30% difference of removal efficiencies is attained as the ozone dose increases from 1.2 mg/L to 8.2 mg/L. And the turbidity removal was increased with increasing ozone dose. Therefore it can be concluded that ozone in this flotation system facilitates improved removal of organic matter and turbidity due to enhanced destabilization of those.

APA, Harvard, Vancouver, ISO, and other styles

13

Chou, Chung-Yi, Chien-Pin Huang, Neng-Chou Shang, and Yue-Hwa Yu. "Treatment of local scrubber wastewater for semiconductor by using photo-catalytic ozonation." Water Science and Technology 59, no. 11 (June 1, 2009): 2281–86. http://dx.doi.org/10.2166/wst.2009.274.

Full text

Abstract:

This study investigates the oxidation of local scrubber wastewater (LSW) from semiconductor manufacture by using ozonation, catalytic ozonation (ozone/Al2O3 and ozone/TiO2–Al2O3), and photo-catalytic ozonation (UV/TiO2–Al2O3, ozone/UV and ozone/UV/TiO2–Al2O3). The results show that catalyst Al2O3 and TiO2–Al2O3 promotes the TOC removal under the condition of neutral or alkaline buffer solution during catalytic ozonation of LSW. The Al2O3 induces highest promotion in TOC removal efficiency, which is higher than ozone alone by 26% TOC removal under alkaline buffer solution. However, TiO2–Al2O3 and Al2O3 cannot display the promotion in TOC removal under acidic condition. In addition, a pre-treatment of anion ion-exchange is employed and the result indicates that decreasing the anion ions concentration before AOPs can imply higher TOC removal during AOPs of LSW. In this study, ozone/UV under raw LSW acidic condition and ozone/Al2O3 under alkaline buffer solution present 95% and 88% TOC removal rate respectively and show the higher TOC removal efficiency than other AOPs. Therefore, these two kinds of AOP can serve as the very viable AOP methods in the LSW reclamation for semiconductor.

APA, Harvard, Vancouver, ISO, and other styles

14

Wu, Dao Ji, Xiao Xiang Cheng, Xue Dong Zhai, and Yan Jie Wang. "The Combination Process of Ozone/Ultraviolet/Biological Activated Carbon Filter for Treatment of Huaihe Micro-Polluted Water." Applied Mechanics and Materials 295-298 (February 2013): 1384–88. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.1384.

Full text

Abstract:

Aim at experimenting the micro-polluted characteristic of Huaihe River water, a pilot-scale test by the combination process of ozone/ultraviolet (UV) /biological activated carbon (BAC) filter for advanced treatment of drinking water was applied. The removal efficiency of general pollution indexes by combined process with different ozone dosages (1.0~3.0 mg/L) was investigated. Along with the increase of ozone dosage, the removal efficiency of CODMn and UV254 generally increased in ozone/UV oxidation process; The removal effect of NO2--N by ozone/UV oxidation was obvious; The removal of turbidity and NH3-N was mainly in BAC filter phase; When the ozone dosage was 2.0~2.5 mg/L, the general pollution indexes had gotten satisfying results, thus it was not necessary to increase the ozone dosage.

APA, Harvard, Vancouver, ISO, and other styles

15

Wang, Xiao Dong, Yang Lv, Meng Meng Li, and Hong Ye Liu. "Removal of Nonylphenol from Water by Ozone." Advanced Materials Research 859 (December 2013): 357–60. http://dx.doi.org/10.4028/www.scientific.net/amr.859.357.

Full text

Abstract:

This study investigates the degradation of Nonylphenol. The degradation affecting factors including solution ozone dosage, initial concentration, pH, temperature and ultraviolet. The results indicated that when the ozone contents changes, the Nonylphenols degradation rate changes as well. The higher ozone concentration contribute to the faster degradation; With the increase of initial concentration of Nonylphenol, the removal rate of it decrease on the contrary, while with the initial concentration increases, the quality of unit ozone degradation of Nonylphenol is ascenting and then tend to a constant; The remove rate of Nonylphenol is improving when the pH value vary from 4.86~10.34. The effect of Nonylphenols ozonation in higher temperatures is better than it is in lower temperature; Ultraviolet radiation is also favorable for the removal of Nonylphenol as it can shorten the reaction time as well as reduce the amount of ozone.

APA, Harvard, Vancouver, ISO, and other styles

16

Duong, Huy Huu, Vui Thi Kim Tran, Chuong Thanh Nguyen, and Hien Thi To. "Ozone removal efficiency of the KI-denuder in the carbonyl sampling." Science and Technology Development Journal - Natural Sciences 2, no. 5 (July 2, 2019): 153–60. http://dx.doi.org/10.32508/stdjns.v2i5.791.

Full text

Abstract:

In the carbonyl sampling of 2, 4- dinitrophenylhydrazine (DNPH) impregnated cartridge, the ozone removal was necessary because ozone reacted with the DNPH derivatives. A commercial ozone scrubber was usually used to remove O3. However, high humidity leaded to carbonyl compounds being trapped on the ozone scrubber before passing through the DNPH cartridge. The purpose of this study was to assess the ozone removal by KI-denuder under the climatic conditions of Ho Chi Minh City. Several parameters including air sampling flow rate and denuder length were optimized to achieve the highest removal efficiency. The optimum parameters of the KI denuder were the sampling flow rate of less than 1 L/min, and the denuder length of 20 cm. The effect of the initial O3 concentration on the removal efficiency was also investigated. Finally, the ozone removal efficiency of KI-denuder was compared to that of ozone scrubber when two devices were applied for the carbonyl sampling during field measurement. The results show that KI-denuder could be used to replace the ozone scrubber with high removal efficiency, particularly in high humidity condition. In conclusion, KI-denuder was effective, simple, easy to use and cheap. Therefore, it was encouraged to use in carbonyl sampling.

APA, Harvard, Vancouver, ISO, and other styles

17

Alfafara, C. G., V. P. Migo, J. A. Amarante, R. F. Dallo, and M. Matsumura. "Ozone treatment of distillery slop waste." Water Science and Technology 42, no. 3-4 (August 1, 2000): 193–98. http://dx.doi.org/10.2166/wst.2000.0379.

Full text

Abstract:

Ozonation of distillery slop waste was done to evaluate the process in terms of organic matter removal and decolorization efficiencies. The chemical properties of melanoidins, which are known to harbor the chromophoric groups in the waste were also investigated. Ozone had primary effects on the decolorization of the slops and improvement in its biodegradability, compared to organic matter removal (as COD). A decolorization efficiency of 80% and a biodegradability improvement of 40% was obtained in 40 hours. Only 16% of the COD was removed. The melanoidins had a 10% decrease in molecular weight indicating slight depolymerization. UV spectral studies of melanoidins showed that olefinic linkages (which are said to be important in the structure of the chromophores) decreased.

APA, Harvard, Vancouver, ISO, and other styles

18

Horibe, Hideo, Masashi Yamamoto, Tomokazu Ichikawa, Tomosumi Kamimura, and Seiichi Tagawa. "Resist Removal by Using Wet Ozone." Journal of Photopolymer Science and Technology 2, no. 2 (2007): 315–18. http://dx.doi.org/10.2494/photopolymer.2.315.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Horibe, Hideo, Masashi Yamamoto, Tomokazu Ichikawa, Tomosumi Kamimura, and Seiichi Tagawa. "Resist Removal by using Wet Ozone." Journal of Photopolymer Science and Technology 20, no. 2 (2007): 315–18. http://dx.doi.org/10.2494/photopolymer.20.315.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Hoang, Chi P., Kerry A. Kinney, and Richard L. Corsi. "Ozone removal by green building materials." Building and Environment 44, no. 8 (August 2009): 1627–33. http://dx.doi.org/10.1016/j.buildenv.2008.10.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Drury, Douglas D., Shane A. Snyder, and Eric C. Wert. "Using Ozone Disinfection for EDC Removal." Proceedings of the Water Environment Federation 2006, no. 12 (January 1, 2006): 1249–58. http://dx.doi.org/10.2175/193864706783749792.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Derco, Jan, Michal Melicher, Angelika Kassai, Jozef Dudas, and Maria Valicková. "Removal of Benzothiazoles by Ozone Pretreatment." Environmental Engineering Science 28, no. 11 (November 2011): 781–85. http://dx.doi.org/10.1089/ees.2010.0399.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Baig, S., and P. A. Liechti. "Ozone treatment for biorefractory COD removal." Water Science and Technology 43, no. 2 (January 1, 2001): 197–204. http://dx.doi.org/10.2166/wst.2001.0090.

Full text

Abstract:

A two case study of industrial wastewater treatment is reported in order to prove the suitability of ozonation for biorefractory COD removal. The ozone application as an end treatment is shown to provide an excellent oxidation yield of organic matter in a landfill leachate. The combination of ozonation and fixed bed biofilm process appears quite effective for the post-treatment of two biological effluents from paper industry.

APA, Harvard, Vancouver, ISO, and other styles

24

METTS, T., S. BATTERMAN, G. FERNANDES, and P. KALLIOKOSKI. "Ozone removal by diesel particulate matter." Atmospheric Environment 39, no. 18 (June 2005): 3343–54. http://dx.doi.org/10.1016/j.atmosenv.2005.01.027.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Yang, Zhiyong, Penglei Wang, Yagang Zhang, Xingjie Zan, Wenjuan Zhu, Yingfang Jiang, Letao Zhang, and Akram Yasin. "Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors." Molecules 24, no. 24 (December 4, 2019): 4436. http://dx.doi.org/10.3390/molecules24244436.

Full text

Abstract:

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

APA, Harvard, Vancouver, ISO, and other styles

26

Collivignarelli, C., and S. Sorlini. "AOPs with ozone and UV radiation in drinking water: contaminants removal and effects on disinfection byproducts formation." Water Science and Technology 49, no. 4 (February 1, 2004): 51–56. http://dx.doi.org/10.2166/wst.2004.0218.

Full text

Abstract:

In this study, the advanced oxidation with ozone and UV radiation (with two low pressure UV lamps, at 254 and 185 nm wavelength) were experimented on a surface water in order to study the removal of two odorous compounds (geosmin and 2-methylisoborneol) and a pesticide (metolachlor), the influence on organic compounds (UV absorbance and THM precursors) and bromate formation. Different batch tests were performed with ozone concentration up to 10 mg/L, UV dose up to 14,000 J/m2 and a maximum contact time of 10 minutes. The main results show that metolachlor can be efficiently removed with ozone alone while for geosmin and MIB a complete removal can be obtained with the advanced oxidation of ozone (with concentration of 1.5-3 mg/L and contact time of 2Ð3 minutes) with UV radiation (with doses of 5,0000-6,000 J/m2). As concerns the influence on the organic precursors, all the experimented processes show a medium removal of about 20-40% for UV absorbance and 15-30% for THMFP (trihalomethanes formation potential). As concerns bromate formation, the advanced oxidation of ozone/UV 254 nm shows a bromate formation that is about 40% lower with respect to conventional oxidation with ozone.

APA, Harvard, Vancouver, ISO, and other styles

27

Valuntaitė, Vaida, Vaida Šerevičienė, Raselė Girgždienė, and Dainius Paliulis. "RELATIVE HUMIDITY AND TEMPERATURE IMPACT TO OZONE AND NITROGEN OXIDES REMOVAL RATE IN THE EXPERIMENTAL CHAMBER / SANTYKINIO ORO DRĖGNIO IR TEMPERATŪROS ĮTAKA OZONO IR AZOTO OKSIDŲ SUIRIMO GREIČIUI EKSPERIMENTINĖJE KAMEROJE / ВЛИЯНИЕ ОТНОСИТЕЛЬНОЙ ВЛАЖНОСТИ И ТЕМПЕРА ТУРЫ НАС КОРОСТЬ РАСПАДА ОЗОНА И ОКСИДОВ АЗОТА В ЭКСПЕРИМЕНТАЛЬНОЙ КАМЕРЕ." Journal of Environmental Engineering and Landscape Management 20, no. 1 (March 8, 2012): 35–41. http://dx.doi.org/10.3846/16486897.2011.633335.

Full text

Abstract:

The indoor ozone and nitrogen oxides concentration depends on their outdoor concentrations, indoor sources and their removal rates on the surfaces. The paper presents experimental data of the of ozone and nitrogen oxide removal in the chamber. The ambient conditions were simulated by four combination of different temperature and relative humidity levels. The impact of temperature (T = 20 °C and T = 30 °C) and relative humidity (RH = 24% and RH = 80%) on the deposition velocity was estimated. It was found that the ozone removal in the chamber was influenced more by temperature, and the nitrogen oxides removal was affected more by relative air humidity. The results showed that higher ambient temperature (T = 30 °C) increased the ozone removal rate in the chamber 3 times on an average, and high relative humidity (RH = 80%) increased the NOx removal rate 4.5 times in comparison with the initial conditions (T = 20 °C; RH = 24%). The obtained deposition velocities varied in the range (0.0045–0.0137) cm s−1 for ozone and in the range (0.002-0.0129) cm s −1 for nitrogen dioxide. Santrauka Ozono ir azoto oksidų koncentracija patalpose priklauso nuo šių teršalų koncentracijos lauke, jų šaltinių patalpose ir šių teršalų suirimo greičio ant skirtingų paviršių. Darbe nagrinėjamas ozono ir azoto oksidų suirimas eksperimentinėje kameroje. Skirtingos mikroklimatinės sąlygos buvo sukuriamos naudojant keturių skirtingų temperatūrų ir santykinių oro drėgnių lygių derinius. Vertinta temperatūros (T = 20 °C ir T = 30 °C) ir santykinio drėgnio (RH = 24 % ir RH = 80 %) įtaka tiriamų teršalų suirimui. Nustatyta, kad ozono suirimui daugiau įtakos turėjo temperatūra, o NOX irimui – santykinis oro drėgnis. Nustatyta, kad aukštesnė aplinkos temperatūra (T = 30 °C) paspartina ozono suirimą kameroje vidutiniškai tris kartus, o didelis santykinis drėgnis (RH = 80 %) paspartina NOX suirimą 4,5 karto, lyginant su pradinėmis sąlygomis (T = 20 °C; RH = 24 %). Eksperimento metu ozono suirimo greitis kito nuo 0,0045 iki 0,0137 cm s−1, o azoto oksidų – nuo 0,002 iki 0,0129 cm s−1. Резюме Концентрации озона и оксидов азота в помещениях зависят от их концентрации в открытом воздухе, источникахвнутри помещений и скорости их распада на поверхностях. В статье представлены экспериментальные данные по распаду озона и оксидов азота в камере при разных микроклиматических условиях, созданных с применением четырех комбинаций температур и относительной влажности. Оценивалось воздействие температуры (T = 20 °С и Т = 30 °С) и относительной влажности воздуха (RH = 24% и RH = 80%) на скорость осаждения. Было обнаружено,что на распад озона в камере большее влияние оказывает температура, а на распад оксидов азота – относительная влажность воздуха. Результаты показали, что при повышении температуры окружающей среды (T = 30 °С) увеличилась скорость распада озона в камере в 3 раза по сравнению со средней, а при высокой относительной влажности (RH = 80%) увеличилась скорость распада NOx в 4,5 раза по сравнению с начальными условиями (T = 20 °C; RH = 24%). Полученные для озона скорости осаждения варьировали в пределах (0,0045−0,0137) cм с-1, а для оксида азота – в пределах (0,002−0,0129) cм с-1.

APA, Harvard, Vancouver, ISO, and other styles

28

Boucherie, C., C. Lecarpentier, N. Fauchon, M. Djafer, and V. Heim. "“Ozone” and “GAC filtration” synergy for removal of emerging micropollutants in a drinking water treatment plant?" Water Supply 10, no. 5 (December 1, 2010): 860–68. http://dx.doi.org/10.2166/ws.2010.837.

Full text

Abstract:

Ozonation plays an essential role in water disinfection to inactivate viruses, bacteria and some parasites (Giardia). Ozone treatment rates to attain disinfection goals also result in oxidation reactions of emerging pollutants. Pharmaceuticals–except Ciprofloxacin–are very reactive to ozone: they are removed as early as the transfer compartment outlet even at an ozone treatment rate of less than 1 g/m3. Glyphosate, AMPA, Amitrole and Diuron–the four major pesticides in the Seine, Marne and Oise rivers–are reactive to ozone. Twenty-one pesticides are only partially reactive to ozone and an additional “GAC filtration” is needed to remove them. Further investigations have been planned to study the removal of Phthalates, Nonylphenols and Hormones by combining the “Ozone” and “GAC filtration” process units.

APA, Harvard, Vancouver, ISO, and other styles

29

Koch, B., J. T. Gramith, M. S. Dale, and D. W. Ferguson. "Control of 2-Methylisoborneol and Geosmin by Ozone and Peroxone: A Pilot Study." Water Science and Technology 25, no. 2 (January 1, 1992): 291–98. http://dx.doi.org/10.2166/wst.1992.0064.

Full text

Abstract:

A pilot-scale study of ozone and PEROXONE (ozone in combination with hydrogen peroxide) for the removal of the odorous compounds 2-methylisoborneol (MIB) and geosmin in drinking water has been conducted at the Metropolitan Water District of Southern California. The study investigated the effects of ozone dosage, ratio of hydrogen peroxide to ozone (H202/03), and contact time. It was found that MIB and geosmin removal increased with higher applied ozone doses, but longer contact times over the range of 6-12 min were not significant. It was determined that 80-90 percent removal could be achieved with an ozone dose of approximately 4.0 mg/l, as compared to an ozone dose of approximately 2.0 mg/l at a H202/03 ratio of 0.2. Also investigated were the effects of alternative contactor configurations, ferrous sulfate as an alternative coagulant, bromide and ammonia addition, and simulated turbidity on the removal efficiencies of the two odorous compounds.

APA, Harvard, Vancouver, ISO, and other styles

30

Mutseyekwa, Michael Emmanuel, Şifa Doğan, and Saltuk Pirgalıoğlu. "Ozonation for the removal of bisphenol A." Water Science and Technology 76, no. 10 (August 2, 2017): 2764–75. http://dx.doi.org/10.2166/wst.2017.446.

Full text

Abstract:

Abstract The mechanism of byproduct formation and oxidation pathway of bisphenol A (BPA) during ozonation process have been compared under acidic, neutral and alkaline conditions at an applied ozone dose of 5.3 mg·L−1 min−1. Alkaline conditions promoted the fastest removal and the pseudo first-order reaction rate constant was calculated as 0.15 min−1. Complete removal under alkaline conditions (after 30 minutes of reaction time) was achieved with 1.59 mg ozone per mg BPA and 52% mineralization was achieved at 6.04 mg ozone application per mg total organic carbon (after 90 minutes of reaction time). Hydroxyl radical dominated degradation pathway (pH 10) resulted with opening of ring-structured products into Heptanoic acid, methyl ester. Sixty per cent BPA removal occurred under acidic conditions where the ozone was dominant and formation of Cyclohexene-1-carboxylic acid, ethyl ester, Benzaldehyde, 4-hydroxy-3,5-dimethyl- and 2-Phenylbenzoquinone were evidenced. Despite the fact that complete removal was achieved under neutral conditions, mineralization was not remarkable and both hydroxyl radical and ozone-based degradation pattern was evidenced after the treatment.

APA, Harvard, Vancouver, ISO, and other styles

31

Rodríguez, A., R. Rosal, M. J. Gomez, E. García-Calvo, and A. R. Fernandez-Alba. "Ozone-based reclamation of an STP effluent." Water Science and Technology 63, no. 10 (May 1, 2011): 2123–30. http://dx.doi.org/10.2166/wst.2011.298.

Full text

Abstract:

The system ozone and hydrogen peroxide was used to reclaim wastewater from the secondary clarifier from a Sewage Treatment Plant (STP) of Alcalá de Henares (Madrid-Spain). The assays were performed by bubbling a gas mixture of oxygen and ozone, with ∼24 g Nm−3 of ozone concentration, through a volume of wastewater samples for 20 minutes at 25°C . The removal of dissolved micropollutants such as Pharmaceutical and Personal Care Products (PPCPs) and Organic Carbon (TOC) was enhanced by adding periodic pulses of hydrogen peroxide while keeping pH above 8.0 throughout the runs. Removal efficiency ratios in the range of 7–26 mg O3/mg TOC and 0.24 mg O3 /ng micropollutants at 5 minutes of ozonation were assessed as reference data to reclaim wastewater from STP. The relation between the extent of TOC removed and ozone doses used was related by a second-order kinetic model in which the time-integrated ozone-hydrogen peroxide concentration was included.

APA, Harvard, Vancouver, ISO, and other styles

32

Wang, Xiao Dong, Yang Lv, Hong Ye Liu, and Meng Meng Li. "Removal of Bisphenol A from Water by Ozone." Advanced Materials Research 864-867 (December 2013): 155–60. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.155.

Full text

Abstract:

This study investigates the degradation of bisphenol A (BPA). The degradation affecting factors including solution ozone dosage, initial concentration, pH, temperature and ultraviolet. The results indicated that when the ozone contents changes, the BPAs degradation rate changes as well. The higher ozone concentration contribute to the faster degradation; With the increase of initial concentration of BPA, the removal rate of it decrease on the contrary, while with the initial concentration increases, the quality of unit ozone degradation of BPA is ascenting and then tend to a constant; The remove rate of BPA is improving when the pH value vary from 4.86~10.34. The effect of BPAs ozonation in higher temperatures is better than it is in lower temperature; Ultraviolet radiation is also favorable for the removal of BPA as it can shorten the reaction time as well as reduce the amount of ozone.

APA, Harvard, Vancouver, ISO, and other styles

33

Phattarapattamawong, Songkeart, Andreas Marius Kaiser, Ernis Saracevic, Heidemarie Paula Schaar, and Jörg Krampe. "Optimization of ozonation and peroxone process for simultaneous control of micropollutants and bromate in wastewater." Water Science and Technology 2017, no. 2 (April 12, 2018): 404–11. http://dx.doi.org/10.2166/wst.2018.170.

Full text

Abstract:

Abstract The study aims to simultaneously control micropollutants and bromate formations by using ozonation and peroxone process. The batch experiments were run with variations in specific ozone dose (SOD) and hydrogen peroxide-to-ozone (H2O2/O3) ratio. Based on the removal by ozonation and peroxone, micropollutants were categorized into three groups: non-reactive compounds (i.e. amidotrizoate), moderately reactive compounds (i.e. metoprolol, acesulfame potassium, bezafibrate, and benzotriazole), and highly reactive compounds (i.e. carbamazepine and diclofenac). For ozonation and peroxone process, the removals for highly reactive compounds and moderately reactive compounds were 82–99% and 29–99%, respectively. The removal of amidotrizoate was not observed in this study. The effect of ozonation on micropollutant removals was similar to the peroxone process. However, differences in bromate formation were observed. Bromate formation depended on the SOD, while addition of hydrogen peroxide suppressed the bromate formation. The peroxone process at the H2O2/O3 ratio of 0.3 was recommended to bromide-containing water below 100 µg·L−1 for simultaneous control of micropollutants and bromate. Enhancement in micropollutant removals, except for the non-reactive groups, was achieved with either higher SOD or the addition of hydrogen peroxide to ozonation. The micropollutant removal predicted from the second-order kinetic reaction with ozone and •OH exposures was higher than the observed data.

APA, Harvard, Vancouver, ISO, and other styles

34

Inanc, B., F. Ciner, and I. Ozturk. "Colour removal from fermentation industry effluents." Water Science and Technology 40, no. 1 (July 1, 1999): 331–38. http://dx.doi.org/10.2166/wst.1999.0064.

Full text

Abstract:

Large amounts of effluents from the fermentation industry are characterized by high COD and colour. Although significant reduction in COD is achieved through biological treatment processes, a substantial amount of colour remains. Coagulation and flocculation with alum and iron salts are not effective for colour removal. This is due to the nature of colour causing compounds which are almost totally dissolved and resistant to biodegradation. Hence, fermentation industries face difficulties in discharging their coloured effluents into either sewers or surface waters. In this study, colour removal from biological treatment plant effluents of a fermentation industry with lime and ozone was investigated experimentally. Optimum lime dose for reducing the colour to values around 1000 Pt-Co was found as 10.0 g/l, while 0.9 g/l ozone was necessary to obtain the same residual colour. Economic evaluation has indicated that cost of lime treatment was 1.3 to 1.4 USD/m3 while it was 2.5 USD/m3 for ozone treatment. Annual total costs for lime and ozone treatment were also estimated as 2 million USD and 3.65 million USD, respectively.

APA, Harvard, Vancouver, ISO, and other styles

35

Cheek, J. M., R. J. McDonald, L. Rapalyea, B. K. Tarkington, and D. M. Hyde. "Neutrophils enhance removal of ozone-injured alveolar epithelial cells in vitro." American Journal of Physiology-Lung Cellular and Molecular Physiology 269, no. 4 (October 1, 1995): L527—L535. http://dx.doi.org/10.1152/ajplung.1995.269.4.l527.

Full text

Abstract:

After acute exposure to oxidant gases in vivo, migration and accumulation of inflammatory cells in pulmonary epithelium coincides with epithelial cell necrosis. The present study was designed to test quantitatively the hypothesis that quiescent neutrophils enhance the removal of oxidant-injured pulmonary epithelial cells after exposure to ozone in vitro. Primary isolated rat alveolar type II cells were cultured as monolayers, using serum-free medium. After exposure to 0.1-0.5 ppm ozone for 0.5 h, apical sides of monolayers were administered either fresh nutrient medium only or medium containing quiescent human neutrophils. Monolayer bioelectric properties and cellular uptake of vital dye were recorded from 5 to 48 h after ozone exposure. Ozone dose-dependent increases in monolayer permeability were associated with proportionally higher numbers of injured epithelial cells. However, the direction and magnitude of neutrophil effects on monolayer permeability after ozone exposure were dependent on ozone concentration. Furthermore, neutrophil-treated monolayers exposed to 0.1 ppm ozone had significantly fewer attached cells positive for uptake of vital dye relative to monolayers exposed to the low level of ozone only; this effect was ablated with increasing ozone concentration. These data suggest that at high levels of ozone neutrophils may exacerbate injury to oxidant-impaired epithelial cells, whereas the presence of neutrophils after exposure to ambient concentrations of ozone may expedite the restoration of epithelial barrier function. We conclude that, by enhancing the removal of injured cells, neutrophils may facilitate the repair of centriacinar epithelium after ozone exposure in vivo.

APA, Harvard, Vancouver, ISO, and other styles

36

Roche, P., and M. Prados. "Removal Of Pesticides By Use Of Ozone Or Hydrogen Peroxide/Ozone." Ozone: Science & Engineering 17, no. 6 (December 1995): 657–72. http://dx.doi.org/10.1080/01919512.1995.10555777.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Heleno, Fernanda F., Maria Eliana LR de Queiroz, Lêda RA Faroni, Antônio A. Neves, André F. de Oliveira, Luiz PL Costa, and Gustavo G. Pimenta. "Aqueous ozone solutions for pesticide removal from potatoes." Food Science and Technology International 22, no. 8 (July 9, 2016): 752–58. http://dx.doi.org/10.1177/1082013216651179.

Full text

Abstract:

The presence of pesticide residues in potatoes is of concern because of the potential impact to human health due to the high consumption of this vegetable. In this study, aqueous solutions with and without ozone saturation as postharvest wash treatment at pH 4.0, 7.0, and 9.0 were tested to remove chlorothalonil from potatoes. The method used for pesticide analysis has been validated, presenting recovery values of 94–103%, with variations in the repeatability coefficients of ≤10.6%, and a quantification limit of 0.05 mg kg−1. Regardless of pH, treatment with aqueous ozone solutions removed 70–76% of the pesticide present in the potato. In the no-ozone treatments, the percentage average removal of chlorothalonil residues in potatoes was only 36%. Over 24 days of storage, the quality of potatoes washed with aqueous ozone solutions was not significantly different from those washed with pure water.

APA, Harvard, Vancouver, ISO, and other styles

38

Horibe, Hideo, and Yousuke Goto. "Development of an Environmentally Friendly Resist-Removal Process Using Wet Ozone." International Journal of Polymer Science 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/937928.

Full text

Abstract:

We investigated the removal of polymers with various chemical structures and the removal of ion-implanted resists using wet ozone. The removal rates of polymers that have carbon-carbon (C–C) double bonds in the main chain were high. The main chain of these polymers may be decomposed. The removal rates of polymers that have C–C double bonds in the side chain were low. The benzene ring in the side chain changes into carboxylic acid, so their ability to dissolve in water increased. The polymers without C–C double bonds were not removed. Removal of B and P ion-implanted resists became difficult with increasing acceleration energy of ions at implantation. The resist with plastic-deformation hardness that was twice as hard as that of nonimplanted resist should be removed similarly to nonimplanted resist. Using TOF-SIMS, we clarified that the molecule of cresol novolak resin was destroyed and carbonized by ion implantation.

APA, Harvard, Vancouver, ISO, and other styles

39

Liu, Jian Guang, Qiu Yue Sun, Yan Hao Zhang, Cui Zhen Sun, Xiang Feng Jia, and Wu Chang Song. "Removal of Sulfamethoxazole and Erythromycin from Aqueous Solution by O₃/H₂O₂." Applied Mechanics and Materials 361-363 (August 2013): 716–21. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.716.

Full text

Abstract:

The performance of sulfonamide and macrolide antibiotics in a spiked water removed by O3and O3/H2O2was evaluated uder different conditions such as ozone dosage, pH and H2O2/O3mole ratio. The results showed that O3and O3/H2O2were proved to be effective to oxdize sulfamethoxazole of sulfonamides containing the aromatic ring and erythromycin of macrolides, which were built of mostly saturated hydrocarbon structure, and O3was preferentially to oxidize sulfamethoxazole. With the reaction time of 30 min, when the ozone cocentrations were 2mg/L and 3mg/L, sulfamethoxazole and erythromycin removal efficiency was 93% and 91%, respectively. The sulfamethoxazole and erythromycin were removed completely within 30 min with ozone 6 mg/L. Degradation of sulfamethoxazole containing unsaturated C-C bonds occured easier at low pH only by O3. Degradation of erythromycin with fully saturated structure was difficult, but the improved removal efficiency could be obtained at higher pH. The high concentratins of H2O2to ozonation was favor to remove those antibiotics. At the 0.5 mole ratio of H2O2/O3,the highest removal efficiency could be reached for all the antibiotics .

APA, Harvard, Vancouver, ISO, and other styles

40

Ponnusamy, Guhankumar, Lijo Francis, Kavithaa Loganathan, Oluwaseun O. Ogunbiyi, Saad Jasim, and Jayaprakash Saththasivam. "Removal of cyanotoxins in drinking water using ozone and ozone-hydrogen peroxide (peroxone)." Journal of Water Supply: Research and Technology-Aqua 68, no. 8 (September 19, 2019): 655–65. http://dx.doi.org/10.2166/aqua.2019.028.

Full text

Abstract:

Abstract Presence of cyanotoxins in drinking water poses a great risk to public health. Elevated levels of cyanotoxins in drinking water can lead to acute gastroenteritis, liver diseases, and neurotoxicity. In this study, drinking water samples were collected across the eastern part of Qatar and screened using a rapid assay to detect the presence of microcystins and nodularins. The results showed that the toxin concentrations in all the water samples were below the WHO prescribed limit of 1 μg/L. Considering a worst-case scenario, toxin removal efficiencies were evaluated using ozone and ozone-hydrogen peroxide by spiking drinking water samples with microcystin-LR (MC-LR) at different oxidant dosages, toxin concentrations, water temperatures, and total organic carbon. It was found that peroxone-treated water samples have better MC-LR removal efficiency than molecular ozone at lower oxidant dosages. Nevertheless, at higher oxidant dosages, both ozonation and peroxone oxidation methods showed a similar removal efficiency. The experimental results also clearly indicated that variation in water temperature between 22 °C and 35 °C has minimal effect on the removal efficiency in both the treatment methods. It was also confirmed that the presence of organic carbon has a more profound detrimental impact than water temperature for toxin removal.

APA, Harvard, Vancouver, ISO, and other styles

41

Chen, Siying, Bingzhi Dong, Kuo Gao, and Tian Li. "Pilot study on advanced treatment of geosmin and 2-MIB with O3/GAC." Water Supply 19, no. 4 (November 15, 2018): 1253–63. http://dx.doi.org/10.2166/ws.2018.184.

Full text

Abstract:

Abstract The removal efficiencies of geosmin/2-MIB by conventional treatment (flocculation, sedimentation and sand filtration) combined with advanced treatment (ozonation and granular activated carbon (GAC) filtration) in a pilot-scale experiment were investigated in a comprehensive manner. The objective of this study is to provide useful information for practical applications to solve the taste and odor problem during algal blooms in Lake Taihu. Results showed that the conventional treatment removed 38–59% and 36–64% of 2-MIB and geosmin, respectively, with ozone dosage from 0 to 1.0 mg/L. In particular, the increase in ozone concentration promoted the removal of 2-MIB/geosmin by sand filtration, meanwhile lowering the odorant removal efficiency by GAC filtration, with the key reason being the higher biomass produced in the sand filter through the strengthening effect of the ozonation. The organics with higher molecular weight (MW) showed the most significant decline in the pre-ozonation process with 1.0 mg/L ozone dosage, resulting in an enhanced removal efficiency of 2-MIB/geosmin by pre-ozonation. With ozone dosage of 1.0 mg/L, geosmin and 2-MIB in the treated water were 0.1 and 3.85 ng/L, respectively, which were below their odor threshold concentrations (OTCs) with the preliminary concentration of ∼200 ng/L of 2-MIB/geosmin.

APA, Harvard, Vancouver, ISO, and other styles

42

Abernethy, S., F. M. O'Connor, C. D. Jones, and R. B. Jackson. "Methane removal and the proportional reductions in surface temperature and ozone." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 379, no. 2210 (September 27, 2021): 20210104. http://dx.doi.org/10.1098/rsta.2021.0104.

Full text

Abstract:

Mitigating climate change requires a diverse portfolio of technologies and approaches, including negative emissions or removal of greenhouse gases. Previous literature focuses primarily on carbon dioxide removal, but methane removal may be an important complement to future efforts. Methane removal has at least two key benefits: reducing temperature more rapidly than carbon dioxide removal and improving air quality by reducing surface ozone concentration. While some removal technologies are being developed, modelling of their impacts is limited. Here, we conduct the first simulations using a methane emissions-driven Earth System Model to quantify the climate and air quality co-benefits of methane removal, including different rates and timings of removal. We define a novel metric, the effective cumulative removal, and use it to show that each effective petagram of methane removed causes a mean global surface temperature reduction of 0.21 ± 0.04°C and a mean global surface ozone reduction of 1.0 ± 0.2 parts per billion. Our results demonstrate the effectiveness of methane removal in delaying warming thresholds and reducing peak temperatures, and also allow for direct comparisons between the impacts of methane and carbon dioxide removal that could guide future research and climate policy. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.

APA, Harvard, Vancouver, ISO, and other styles

43

Stern, Marco, Elmar Heinzle, Oemer M. Kut, and Konrad Hungerbühler. "Removal of substituted pyridines by combined ozonation/fluidized bed biofilm treatment." Water Science and Technology 35, no. 4 (February 1, 1997): 329–35. http://dx.doi.org/10.2166/wst.1997.0148.

Full text

Abstract:

3-Methylpyridine (MP) and 5-ethyl-2-methylpyridine (EMP) were quantitatively removed in batch ozonation. Formate, acetate and oxalate where detected as ozonation products representing only about 10% of the total organic carbon after 90% removal of MP. Only 30% of the nitrogen was detected as nitrate. 5 moles of ozone were needed per mol of MP removed but at this time dissolved organic carbon (DOC) was only reduced by 10%. EMP was initially oxidised much faster but the reduction of DOC was only 5% when EMP was removed by 90%. Only 15% of the nitrogen was converted to nitrate. Small amounts of formate, acetate and oxalate were accumulated. 4 moles of ozone were required to remove one mole of EMP. In continuous combined experiments, wastewater was fed to a fluidised bed biofilm reactor with a mixed culture. The liquid was circulated through an ozonation bubble column. Ozone supply was controlled to keep the dissolved ozone concentration at a low level in the oxidation reactor. Complete mineralisation of MP and extensive mineralisation of EMP was observed during the whole experiment. During adaptation of biomass the ozone requirement decreased from 10 mol mol−1 of MP oxidised to 4 mol mol−1.

APA, Harvard, Vancouver, ISO, and other styles

44

Vahala, R., T. Ala-Peijari, J. Rintala, and R. Laukkanen. "Evaluating ozone dose for AOC removal in two-step GAC filters." Water Science and Technology 37, no. 9 (May 1, 1998): 113–20. http://dx.doi.org/10.2166/wst.1998.0347.

Full text

Abstract:

Upgrading an existing post-ozonation plant with two-step granular activated carbon (GAC) filtration for assimilable organic carbon (AOC) removal was studied. The effects of ozone dose on AOC formation and its removal in the subsequent two-step GAC filtration was studied using chemically pretreated 2 to 14° C humic lake water. Two parallel pilot-plant trains with different ozone doses (0 to 1.2 mgO3/mgTOC) and a short-term ozonation study were performed. The optimum ozone dose for maximum AOC formation was 0.4–0.5 mgO3/mgTOC. The AOC-P17 of ozonated water was three-fold higher and AOC-NOX over ten-fold higher than in non-ozonated water, while the following biofiltration (first step) removed 51% and 72% of AOC-P17 and AOC-NOX, respectively. The adsorber (second step) contributed to less than 10% of the overall AOC reduction. It appeared that biofiltration is a feasible method in upgrading water treatment plants for AOC removal even when treating cold humic waters, while the subsequent adsorber seems to have less significance for AOC removal.

APA, Harvard, Vancouver, ISO, and other styles

45

Wu, Hao, Zi Fu Li, Xin Jin, Xin Zhao, and Fu Rong Deng. "Lab Scale Study on Synergistic Disinfection of WWTPS Secondary Effluent by Ultrasonic and Ozone." Advanced Materials Research 433-440 (January 2012): 4751–56. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.4751.

Full text

Abstract:

Secondary effluent from WWTPS still contains a large number of microorganisms, therefore, disinfection is essential. There are many disadvantages in using traditional disinfection methods, so the combination of disinfection techniques is a new research direction. Ozone combined with ultrasound is one of them. In this experiment, the inactivation of the total coli forms, color removal and UV254 removal of secondary effluent by a combination of ultrasonic (frequency20 kHz; power100W) and ozone disinfection was investigated. The results show that the effect of the synergistic action of 30s US and ozone disinfection is superior to the effect of individual ozone disinfection. After 15min synergistic disinfection, the total coli forms inactivation rate is up to 99.9%, simultaneously color removal rate to 80% and UV254 removal rate to 52%. Compared with individual ozone disinfection, reaction time was reduced by 5 min.

APA, Harvard, Vancouver, ISO, and other styles

46

Lee, Shun-hwa, Yun-kyung Park, Miran Lee, and Byung-dae Lee. "Proposal of enhanced treatment process based on actual pilot plant for removal of micropharmaceuticals in sewage treatment plants." Environmental Engineering Research 25, no. 4 (September 4, 2019): 588–96. http://dx.doi.org/10.4491/eer.2019.240.

Full text

Abstract:

This study was carried out to increase the treatment efficiency through the improvement of the conventional biological process, and to propose the optimal treatment direction. The optimal treatment conditions were derived based on the results of the spike damage tests in each single process. The removal efficiency of micropharmaceuticals was further increased when an ozone treatment process was added to the biological process compared to the single process. The soil and activated carbon adsorption process was introduced in the post-treatment to remove the micropharmaceutical residues, and the removal efficiency of the pharmaceduticals in the final effluent was more than 85% in spike damage experiment. In particular, the continuous process of biological treatment-ozone-adsorption could ensure the stable treatment of micropharmaceuticals, which had not been efficiently removed in the single process, as it showed more than 80% removal efficiency. Therefore, it is expected that the addition of the ozone oxidation and activated carbon adsorption process to the existing sewage treatment facilities can contribute to the efficient removal of micropharmaceuticals.

APA, Harvard, Vancouver, ISO, and other styles

47

Yargeau, Viviane, and Félix Danylo. "Removal and transformation products of ibuprofen obtained during ozone- and ultrasound-based oxidative treatment." Water Science and Technology 72, no. 3 (May 19, 2015): 491–500. http://dx.doi.org/10.2166/wst.2015.234.

Full text

Abstract:

The oxidation of ibuprofen (IBP) in water was evaluated using oxidative treatments: ozonation, sonication, hydrogen peroxide addition and combinations of these processes. After 20 minutes of treatment, ozone coupled with hydrogen peroxide at pH 7, 15 °C, an ozone dose of 16 mg/L and a hydrogen peroxide concentration of 7.1 mg/L was found to have the highest IBP (95%) and chemical oxygen demand (COD) (41%) removals. A synergistic effect was observed for the combined ozonation/sonication process, which might be explained by an improved mass transfer of ozone in the solution due to the presence of ultrasonic pressure waves. Transformation products were detected in the treated solutions. The nature of five of these products was confirmed by liquid chromatography–mass spectrometry (LC-MS), including 4-isobutylacetophenone (4-IBAP), oxo-IBP, 4-acetylbenzoic acid, 4-ethybenzaldehyde and oxalic acid. In addition, COD analyses for each experiment showed that the ratio of %COD removal to %IBP removal was highest with sonication; suggesting that this oxidative process offers other mechanisms of removal which may lead to further degradation of products formed. This study presents the first data on removal of IBP by sonication coupled to ozonation and provides some insight into the potential of this combined treatment approach for the removal of contaminants of emerging concern.

APA, Harvard, Vancouver, ISO, and other styles

48

URANO, HIROMI, and SATOSHI FUKUZAKI. "Facilitation of Cleaning of Alumina Surfaces Fouled with Heat-Treated Bovine Serum Albumin by Ozone Treatment." Journal of Food Protection 64, no. 1 (January 1, 2001): 108–12. http://dx.doi.org/10.4315/0362-028x-64.1.108.

Full text

Abstract:

Facilitation of cleaning of alumina (Al2O3) particles fouled with heat-treated bovine serum albumin (BSA), which contains sulfhydryl groups on the molecule, by gaseous ozone was studied. With increasing temperature of heat treatment, the amount of adsorbed BSA onto Al2O3 surfaces increased, whereas the rate of BSA desorption during alkali cleaning decreased markedly, resulting in the larger amounts of BSA remaining on Al2O3 surfaces. No significant amounts of BSA were removed from Al2O3 surfaces by alkali cleaning alone when treated at temperatures above 120°C. Before alkali cleaning, the heat-treated, BSA-fouled Al2O3 at 150°C were treated with 0.05 to 0.30% (vol/vol) gaseous ozone at room temperature. Ozone pretreatment markedly accelerated the rate of BSA desorption during subsequent alkali cleaning. The effect of ozone pretreatment on BSA removal depended on the concentration of ozone and treatment time and hence on the total amount of ozone supplied. The molecular weight (MW) of desorbed BSA during alkali cleaning without ozone pretreatment coincided with the MW of the native BSA, whereas the MW of desorbed BSA during the combined ozone-alkali cleaning was lower than the MW of the native BSA. This indicated that the heat-treated BSA molecules adsorbed on Al2O3 were partially decomposed into some fragments by ozone pretreatment, resulting in the facilitation of the removal of BSA during alkali cleaning.

APA, Harvard, Vancouver, ISO, and other styles

49

Yazgan, M. S., and C. Kinaci. "β-endosulfan removal from water by ozone oxidation." Water Science and Technology 48, no. 11-12 (December 1, 2004): 511–17. http://dx.doi.org/10.2166/wst.2004.0901.

Full text

Abstract:

β-endosulfan solutions were ozonated in a lab scale semi-batch reactor in various experimental conditions. Ozonation kinetics of β-endosulfan and effects of some parameters such as pH, temperature, partial pressure and ozone dosage on oxidation were investigated. Increasing ozone dosage and decreasing of temperature and pH increased the oxidation rate of β-endosulfan. Maximum 97% of β-endosulfan could be removed at both 16-mg/min ozone dosages and pH = 4 for 60 minutes of ozonation. The order of the reaction is determined as pseudo first order. Although the rate of reaction was lower than other pesticide oxidation rates cited in the literature, β-endosulfan reaction to ozonation was achieved with almost 90% removal rate. The temperature dependent rate constant for β-endosulfan oxidation was determined as kd = 0.947 exp(-2.16 × 10-3/T).

APA, Harvard, Vancouver, ISO, and other styles

50

Choi, H., Y. Y. Kim, H. Lim, J. Cho, J. W. Kang, and K. S. Kim. "Oxidation of polycyclic aromatic hydrocarbons by ozone in the presence of sand." Water Science and Technology 43, no. 5 (March 1, 2001): 349–56. http://dx.doi.org/10.2166/wst.2001.0323.

Full text

Abstract:

A series of soil slurry experiments was performed to investigate the characteristics of PAHs removal by ozone in various conditions. Gaseous ozone was bottled into the aqueous phase in the presence of soil contaminated by PAHs. The effects of soil media, OH radical scavengers, ozone dosage, and humic acid were examined at the given experimental conditions. There exists a substantial difference in the removal of PAH according to the types of soil media tested. Baked sand showed the highest removal efficiency compared to the others. The descending order of removal rate was: BS>S>GB. This is considered to be due to the OH radical effect produced by catalytic reactions of ozone with the reactive site on the and. This is qualitatively proved by the experiment of scavenging OH radicals using tert-butanol. The comparison of half-lives of ozone in sand and glass bead columns further supports this hypothesis. It was found that about 22% of enhancement of phenanthrene destruction was accomplished by OH radicals produced by the catalytic ozone decomposition. The rate of ozone consumption for the phenanthrene oxidation was obtained as 1.88 mg/mgO3/min.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Ozone removal'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles