Dissertations / Theses on the topic 'Adsorption, copper'

Thesis (Ph.D.)--Tufts University, 2001.<br>Adviser: Roger G. Tobin. Submitted to the Dept. of Physics. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

During the last few decades governments all around the world have increased concerns about water shortages and pollution. Consequently, they issued a multitude of environmental legislations and regulations, land and water-use planning measures, and other environmentally related procedures. The objective of this work was to contribute in developing efficient adsorbent for heavy metal ions from wastewater. Two different kinds of adsorbents were studied: MCM-41 (Mobil Catalytic Material number 41) mesoporous silica whose pores have been expanded by a post-synthesis hydrothermal treatment in the presence of N,N-dimethyldecylamine (DMDA), and 3-aminopropyltrimethoxysilane (AMP) grafted MCM-41 after being pore expanded and calcined. The pore-expanded MCM-41, (PE)MCM-41, (i.e., containing DMDA) has been tested as adsorbent for Cu2+ cations. Regeneration ability and factors affecting the stability of this material such as pH and stirring time have been investigated. The results showed that (PE)MCM-41 is fast, sensitive, and high capacity adsorbent. However, it is not an appropriate material for environmental applications due to its poor stability in aqueous solutions. Further studies using calcined and pore-expanded MCM-41, (CPE)MCM-41, silica as support for grafting AMP have been carried out. A systematic investigation of the amine loading as a function of the relative amount of AMP and water used during the grafting procedure was carried out. The surface characteristics, AMP loading, Cu2+ adsorption capacity, CO2 adsorption capacity, and rate of CO2 adsorption were determined for all materials. Surface area, pore size and pore volume decreased significantly from 950 m 2/g, 11.3 nm and 2.16 mL/g for unmodified (CPE)MCM-41 to 783 m 2/g, 7.4 nm and 1.54 mL/g for the materials grafted under dry conditions in the presence of 1.0 mL AMP/g silica, and to 730 m2/g, 6.34 nm and 0.77 mL/g for the materials grafted under wet conditions in the presence of 2.0 mL AMP/g silica and 0.4 mL water/g silica. The maximum amine loading, CO2 adsorption capacity and Cu2+ adsorption capacity suggested that the optimum grafting conditions are 2 mL AMP/g silica and 0.4 mL of water/g silica, and that any excess of water or amine added to the grafting mixture has negative effect on the adsorption performance of the material. Two approaches have been investigated to recycle the copper loaded adsorbent: treatment with acidic solution and treatment with complexing agent, ethylenediamine-tetra acetic acid tetra sodium salt (EDTA). The results showed a significant drop in the adsorption capacity after the first regeneration cycle. With further testing of the material, it was concluded that the (CPE)MCM-41 is not stable when being in contact with water and thus, even the material was still loaded with amine, structural changes of the material caused the amine to become inaccessible for Cu2+ or CO2 molecules. So, further work is still required to improve the stability of this material in water or to use more robust material.

The adsorption and interaction of HCN has been studied on (a) copper oxides on crystalline chromia, (b) mixtures of chromium (III) oxide and copper oxides on silica, and (c) mixtures of Cr(VI)O3 and CuO on silica. The adsorption and reaction of both HCN and C2N2 on Cr(VI)O3/SiO2 has also been studied. The work has involved gravimetric studies with a vacuum microbalance, infra-red spectroscopy of adsorbed species, and mass spectroscopic analysis of products. HCN contact at 293 K with both CuO/a-Cr2O3 and CuO-Cr2O3/SiO2 samples led to the slow release of cyanogen. The cyanogen reaction was shown to be occurring on the copper ions of the surface accompanied by reduction to cuprous hydroxide. Some HCN adsorption also occurred on this surface and on the chromia part of the surface without oxidation to cyanogen. On heating, some HCN was desorbed intact but most was oxidised to CO2 with some retention of nitrogen compounds on the surface. The infra-red work indicated that on the copper oxide part of the surface this oxidation occurred via an isocyanate, NCO, intermediate. On the chromia part of the surface HCN adsorption produced an amide species which decomposed to CO2 and N2. Pre-reduction of the surface suppressed cyanogen formation upon HCN adsorption, although considerable oxidation still occurred on heating. On Cr(VI)O3/Aerosil both HCN and C2N2 formed surface amides. On heating, there was some decomposition to CO2 and N2, as with Cr (III) oxide, but also in some cases sublimation of oxamide. With Cr(VI)O3-Cu(II)O/Aerosil, much less gaseous C2N2 was produced from HCN than on Cr2O3/CuO/Silica. This suggests that cyanogen was being preferentially adsorbed on the Cr(VI)O3. The results show the importance of the oxidation states of Cu and Cr in determining the surface reactions of HCN.

Adsorption takes place whenever a solid surface is exposed to a gas or liquid, and is characterized by an increase in fluid density near the interface. Adsorbents have attracted attention in the ongoing effort to engineer materials that can effectively remove various pollutants from wastewaters. Carbon adsorbents are a logical choice as an adsorption material due to their low costs and large surface areas. The adsorption of chromium(VI), aluminium and copper onto commercial activated carbon was studied in a series of batch, kinetic and column experiments. The adsorption of the three ions was studied separately followed by studies of the competition between the ions in binary and ternary systems. The experimental data was utilized to set up models for sorption of chromium(VI), aluminium and copper onto commercial activated carbon. This was done to enhance the understanding of the governing processes controlling adsorption as well as to develop a tool to predict the fate of chromium(VI), aluminium and copper in a calcareous environment. To avoid the precipitation of the ions, the binary and ternary experiments were conducted without pH adjustment. This thesis has used multiple analytical techniques in order to enhance the knowledge of Cr(VI), AI(III) and Cu(II) binding to the activated carbon adsorbent and thus attempts to interpret.the potential binding mechanisms. The changes in adsorbent functional groups and surface topography after chromium binding were monitored using FT-IR and SEM/EDX analysis. The experimental studies include: i) evaluation and characterisation of the commercial activated carbon; ii) evaluation and optimisation of commercial activated carbon removal capability, kinetics and mechanisms toward Cr(VI), AI (III) and Cu(II) via the batch, kinetic and continuous adsorption systems. From the pH studies, it was observed that pH 2 produced the highest removal of chromium. The ternary solution at pH 2 showed less removal of chromium than the other solutions suggesting that the combined -effect of Cu and AI metals was more considerable. Two common adsorption isotherms, i.e. the Freundlich and Langmuir models As well as Redlich-Peterson model were employed to describe the adsorptive characteristics of the activated carbon. The adsorptive kinetic studies revealed that the adsorption of activated carbon followed the pseudo-second order kinetic models, indicating the adsorption mechanism was dependent on the adsorbate and adsorbent interaction.

During the 1990s, shellfish hatcheries operating on the Eastern Shore of Virginia noticed an increase in mortalities of their clam larvae; it was suspected that this was a result of the deteriorating quality of the estuarine water used by aquaculture hatcheries. Many hatcheries obtain their facility process water directly from nearby streams and estuaries. During the same time period, there was also an increase in the use of plastic mulch on some of the vegetable fields on the Eastern Shore. The increased runoff commonly associated with these plastic-covered fields often contains copper-based bactericides that are used on the crops. The plasticulture fields were often located adjacent to the same estuaries from which the shellfish hatcheries draw their water. High levels of copper were measured in multiple surface water locations near these fields. Runoff associated with the plasticulture fields contained up to 238 ug/L dissolved copper, well in excess of the copper concentration of 16.4 ug/L dissolved copper known to affect the mortality of larval clams. Surface water samples collected from nearby unimpacted water bodies contained less than 4 ug/L dissolved copper. Sorption studies conducted with synthetic estuary water quantified the dissolved copper sorption capacities of eight sorbents, including GACs, zeolites, a greensand, and an ion exchange resin, Amberlite IRC-718. These isotherm studies showed that all sorbents removed soluble copper, and that increased salinity and a greater contact time were shown to increase sorption. Utilizing the Freundlich isotherm, the capacity of the eight sorbents studies ranged from 25 to 221 ug/g with a 24-hour contact time. Column studies with an influent concentration of 300 ug/L dissolved copper showed that using 10 grams of a GAC sorbent, a flow rate of 5 mL/min maintained the target effluent concentration of less than 16.4 ug/L for approximately 100 hours. A similar column using 10 g of resin sorbent at a flow rate of 12.5 mL/min maintained the target effluent concentration for approximately 300 hours. The high removal capacity of the resin makes it a desirable treatment for controlling copper in estuarine water used for aquaculture. Utilizing the sorbent capacities obtained from the Freundlich isotherm and a batch treatment, a typical 500 gallon tank used for clam aquaculture would require approximately four pounds of a GAC sorbent, or two pounds of the resin sorbent to reduce a source water that contains 300 ug/L of dissolved copper to below the larval clam toxicity level. Both sorbents would require a 24-hour contact time.<br>Master of Science

CO2 capture and conversion appears to be a prominent solution to mitigate greenhouse gas emissions (GHG) and global warming issue. Among different CO2 conversion approaches, CO2 hydrogenation via reverse water gas shift (RWGS) reaction is one of the most promising technology to convert CO2 to CO. Subsequently, CO is transformed to value added chemicals or liquid fuels. To improve the overall CO2 conversion for RWGS reaction, product separation and recycling is being proposed. In this research, adsorption separation technology has been explored to selectively separate CO from CO2 in RWGS using pressure swing adsorption (PSA) process. To investigate the adsorption capacity and selectivity of CO, different porous materials have been identified for CO separation. In this research, activated carbons, ordered mesoporous silica, and metal organic framework materials were studied. Equilibrium isotherms of CO and CO2 were measured in a gravimetric system at a temperature of 25 °C for pressures up to 20 bar. Preliminary adsorption isotherm results had shown an insufficient CO uptake and low selectivity level compared to CO2, thus not justifying their application for CO separation. Herein, to improve the CO adsorption capacity and selectivity, Cu-based adsorbents were developed using copper (II) chloride (CuCl2) as a precursor to synthesize six different adsorbents. The adsorbents were prepared using two different synthesis methods; the modified polyol method for reduction and nanoparticle deposition of Cu (I) ions, and thermal monolayer auto-dispersion method. Furthermore, different copper (II) loadings were investigated to determine the monolayer dispersion capacity of CuCl2 on the support. The modified adsorbents by copper salt exhibited significantly high CO uptake with large CO/CO2 selectivity, reversing the results obtained before adsorbent modification. Thus, Cubased adsorbents are promising materials for CO separation and recovery from a gaseous mixture containing CO2.

Azolla filiculoides has been evaluated for the adsorption of trace toxic metals from aqueous solution. The adsorption performance of the material was compared with commercial resins and fitted using the Langmuir and Freundlich models. The Freundlich model described the adsorption of copper and cadmium. Whilst the Langmuir isotherm had the better fit of the mercury data. The assumptions of the Freundlich model include multi-layer adsorption and different functional group binding. Conversely the Langmuir model suggests mono-layer adsorption and can infer single group reactivity. The pH effect on the uptake of the metals was investigated and an increase in removal was observed at higher pH with all the metals studied. The material has been thoroughly characterised using physical methods, such as, scanning electron microscopy X-ray photoelectron spectroscopy and electrophoretic mobility measurements. This enabled conclusions to be made regarding the surface functionality of the solid. Chemical characterisation included direct titrations, revealing a gradual dissociation of acidic groups as the pH increased within the experimental range. Kjeldahl nitrogen and amino acid analysis of several biological materials that have been used in metal sorption experiments showed A. filiculoides as having a large proportion of these cell constituents. The kinetics of metal ion uptake by the biosorbent was investigated and compared with commercially available resins. The kinetics are slower than conventional ion exchange resins and carbon adsorbents but entirely adequate for utilisation in a column process. The mechanism hypothesized for metal ion removal by the biosorbent is primarily attributed to ionogenic groups exchanging ions for copper and cadmium removal. Mercury on the other hand is said to be predominantly involved in a reduction-precipitation reaction on the surface of the adsorbent. Regeneration was successfully accomplished for copper and cadmium after minicolumn trials, with greater than 95 % elution of the metals using 0.1M HCI. The mini column trials showed a sharp breakthrough for these metals singularly and a dynamic equilibrium was observed during multi-metal processing. Mercury removal was much slower and more difficult with the same eluant, achieving a maximum of 50% removal. A method for a semi-continuous biosorbent process has been evaluated and proven to be successful in processing metal laden solution.

Plasma polymerization techniques were used to synthesize and deposit hydrogel on silicon (Si) substrate. Hydrogel is a network of polymer chains that are water-insoluble and has a high degree of flexibility. The various fields of applications of hydrogel include drug release, biosensors and tissue engineering etc. Hydrogel synthesized from different monomers possess a common property of moisture absorption. In this work two monomers were used namely 1-amino-2-propanol (1A2P) and 2(ethylamino)ethanol (2EAE) to produce polymer films deposited on Si ATR crystal. Their moisture uptake property was tested using FTIR-ATR technique. This was evident by the decrease in -OH band in increasing N2 purging time of the films. Secondly, two monomer compounds namely vinyl acetic acid and glycidyl methacrylate which have both amine and carboxylic groups are used as solid surface for the immobilization of bovine serum albumin (BSA). Pulsed plasma polymerization was used to polymerize these monomers with different duty cycles. Initial works in this field were all about protein surface adsorption. But more recently, the emphasis is on covalent bonding of protein on to the surface. This immobilization of protein on solid surface has a lot of applications in the field of biochemical studies. The polymerization of vinyl acetic acid and glycidyl methacrylate were shown as successful method to attach protein on them. Chemical mechanical polishing (CMP) of Cu is one of the processes in the integrated chips manufacturing industry. Benzotriazole is one of the constituents of this CMP slurry used as corrosion inhibitor for Cu. Benzotriazole (C6H5N3) is a nitrogen heterocyclic derivative having three nitrogen atoms, each with an unshared pair of electrons, forming five-membered ring structure. This molecule coordinates with Cu atoms by loosing a proton from one of its nitrogen atom and thereby forming a film which is polymeric in nature that prevents further oxidation of Cu. In this work, aqueous solution of BTA was used to study the adsorption characteristics on Cu when a Cu electrodeposited Si was immersed in to it. This study was performed using ATR-FTIR technique. The adsorption of BTA on Cu surface was evident by the presence of aryl C-H stretching band at 3061 cm-1.

During the last few decades, concerns about water shortages and pollution have increased. Consequently, environmental legislations and regulations for wastewater discharge have been issued. The objective of this work was to contribute in developing an efficient dsorbent for removing heavy metal ions from wastewater. The thesis focused on evaluating amine-modified SBA-15 as copper and other heavy metal ions adsorbent, by determining a variety of adsorptive properties with the aim of gaining a deep understanding of its behavior and to outline its advantages and limitations. The influence of synthesis conditions on the mesostructural stability of the resultant materials after different water treatments was systematically investigated. N2 adsorption results indicated that the material prepared via co-condensation and aged at 100 ºC was not stable and lost its ordered mesoporous structure after contacting water even at room temperature. Aging at 130 ºC and addition of inorganic salts resulted in materials that maintained their mesporous structure under different water treatments. The material synthesized in the presence of KCl was used as adsorbent for the rest of the thesis work. It was shown that the structural collapse observed in amine-modified SBA-15 prepared by conventional method when contacted with aqueous solutions is associated with the drying process, and not the treatment itself. This structural collapse was avoided by replacing water with more volatile liquids such as acetone, before drying. Amino-functionalized SBA-15 was tested for the removal of copper ions from aqueous solutions under different temperatures, pH, initial concentrations and agitation speeds. The obtained results indicated that the amino-functionalized SBA-15 was very efficient and equilibrium was achieved in less than 30 min at room temperature. The adsorption capacity increased dramatically with increasing temperature, initial copper concentration and pH. Under suitable conditions, the material exhibited high adsorption capacity even at very low copper concentration. To further investigate the effect of dsorption parameters, a 24 factorial design experiments were used to screen the factors affecting the copper removal efficiency. All the parameters main effects were significant within a 95 % confidence level. Surface composite design was used to develop a reliable model representing the adsorption process. The statistical tests used proved the adequacy of the second order model. Optimization of the factors levels was carried out and the recommended optimum conditions are: copper concentration of 20 mg/L, adsorbent/solution ratio of 1.57 g/L, pH of 6.5, and T = 294 K with 95% copper removal. The effect of regeneration conditions was investigated after three adsorption–desorption cycles, under different batchwise regeneration conditions. Using a composite surface design methodology, the effect of the regeneration conditions on the performance of the adsorbent was investigated. It was found that all the studied parameters have a statistically significant influence on the working dsorption capacity. With respect to structural properties and amine content, none of the factors was found to be significant. Regeneration using EDTA was found to be more efficient than acid treatment. Amino-functionalized SBA-15 was studied as potential absorbent for Cd2 +, Co2 +, Cu2 +, Zn2 +, Pb2 +, Ni2 +, Al3+ and Cr3 +. The adsorption capacity and selectivity of the material were investigated in single and multi-metal solutions. Using very dilute solutions, i.e., 10 ppm, more than 95% of cations were removed, except for Co2+ and Cr3 +, indicatingthe high sensitivity of the current adsorbent. The adsorption capacities in multi-metal solutions were lower than in single-metal ones because of competition between metallic elements for the amine groups. The adsorbent was not affected in the presence of sodium, potassium, and calcium, indicating that the ionic strength does not affect the adsorption properties. Application of this material to remove copper in tap water, river water, and electroplating wastewater was shown to be successful. Dynamic experiments were carried out on the adsorption of copper ions in a laboratory packed-bed of amine-modified SBA-15. Breakthrough curves were analyzed at different flowrates and after two adsorption-desorption cycles. Furthermore, a model based on mass balance was developed and tested for predicting the breakthrough curves under different experimental conditions used. The results suggested that the developed model was in good agreement with the experimental data. Bed regeneration was performed by circulating 0.2 M EDTA solution through the column for 30 min. Résumé Durant les quelques dernières décennies, les préoccupations concernant les pénuries d'eau et la pollution en général ont augmenté. Par conséquent, des législations et des réglementations environnementales pour les rejets d'eaux usées ont été introduites. L'objectif de ce travail était de contribuer au développement d'un adsorbant efficace pour éliminer les ions de métaux lourds des eaux usées. Cette thèse porte sur l'évaluation de SBA-15 modifiée avec des amines comme adsorbant pour le cuivre et d'autres ions de métaux lourds par la détermination d'une multitude de propriétés d'adsorption dans le but d'acquérir une profonde compréhension de son comportement et d’identifier ses avantages et ses limites. L'influence des conditions de synthèse sur la stabilité des matériaux mésoporeux obtenus après différents traitements a été étudié de façon systématique. Les résultats d'adsorption de N2 ont indiqué que le matériel préparé par co-condensation et vieilli à 100 °C n'était pas stable et a perdu sa structure mésoporeuse ordonnée après avoir été en contact avec l'eau même à température ambiante. Le vieillissement à 130 °C, avec ajout de sels inorganiques, a abouti à des matériaux qui ont maintenu leur structure mésoporeuse sous différents traitements en présence d'eau. Le matériau synthétisé en présence de KCl a été utilisé comme adsorbant pour le reste du travail de cette thèse. Il a été démontré que l'effondrement de la structure observé dans la SBA-15 modifiée aux amines, préparée par la méthode conventionnelle en contact avec des solutions aqueuses est associé avec le processus de séchage, et non le traitement lui-même. Cet effondrement de structure a été évité en remplaçant l'eau avec des liquides plus volatils tels que l'acétone, avant le séchage. La SBA-15 amino-fonctionnalisée a été testée pour l'élimination des ions de cuivre des solutions aqueuses à différentes températures, pH, concentrations initiales et vitesses d'agitation. Les résultats obtenus ont indiqué que la SBA-15 amino-fonctionnalisée était très efficace et l'équilibre a été atteint en moins de 30 min à température ambiante. La capacité d'adsorption a considérablement augmenté avec la température, la concentration initiale de cuivre et le pH. Sous des conditions appropriées, le matériau a manifesté une grande capacité d'adsorption, même à des concentrations très faibles en cuivre. Afin d’étudier l'effet des paramètres d'adsorption, un plan factoriel de 24 expériences a été utilisé pour dépister les facteurs affectant l'efficacité d'élimination du cuivre. Tous les effets principaux des paramètres étaient importants à 95% de niveau de confiance. La méthodologie de la surface composite a été utilisée pour développer un modèle fiable qui représente le processus d'adsorption. Les tests statistiques utilisés ont prouvé la pertinence du modèle de second ordre. L’optimisation des niveaux des facteurs a été effectuée et les conditions optimales recommandées sont: la concentration en cuivre de 20 mg/L, le rapport adsorbant/solution de 1.57 g/L, pH de 6.5 et T = 294 K pour l'élimination de 95% de cuivre. L'effet des conditions de régénération a été étudié après trois cycles d'adsorption-désorption, sous différentes conditions de régénération. En utilisant la méthodologie de la surface composite, l'effet des conditions de régénération sur la performance de l'adsorbant a été étudié. Il a été constaté que tous les paramètres étudiés ont une influence statistiquement significative sur la capacité de travail d'adsorption. En ce qui concerne les propriétés structurelles et la teneur en amine, aucun des facteurs n’a été jugé significatif. La régénération à l'aide d'EDTA a été jugée plus efficace que le traitement acide. La SBA-15 amino-fonctionnalisée a été étudiée comme absorbant potentiel de Cd2+, Co2+, Cu2+, Zn2+, Pb2+, Ni2+, Al3+ and Cr3+. La capacité d'adsorption et la sélectivité du matériau ont été étudiées dans des solutions mono- et multi-métalliques. En utilisant des solutions très diluées, soit 10 ppm, plus de 95% de cations ont été enlevés, sauf pour le Co2+ et Cr3+, indiquant la forte sensibilité de l'adsorbant. Les capacités d'adsorption dans les solutions multi-métalliques étaient inférieures à celles des solutions mono-métalliques en raison de la concurrence entre les éléments métalliques pour les groupes amine. L'adsorbant n'a pas été affecté par la présence de sodium, de potassium et de calcium, ce qui indique que la force ionique n'affecte pas les propriétés d'adsorption. L’usage avec succès de ce matériau pour éliminer le cuivre dans l'eau de robinet, l’eau de rivière et les eaux usées de galvanoplastie a été démontré. Des expériences dynamiques ont été réalisées sur l'adsorption des ions de cuivre par la SBA-15 amine-modifiée sur une colonne à lit fixe de laboratoire. Les courbes de perçage ont été analysées à des débits différents et après deux cycles d'adsorption-désorption. De plus, un modèle basé sur le bilan de matière a été développé et testé pour prédire les courbes de perçage sous les différentes conditions expérimentales utilisées. Les résultats suggèrent que le modèle développé est en bon accord avec les données expérimentales. La régénération du lit a été réalisée en faisant circuler une solution EDTA à 0.2 M à travers la colonne pendant 30 min.

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This study investigated the chemical modification method by citric acid and its enhancement effect on the adsorption capacity of sugarcane bagasse (SB) for copper removal from aqueous solution. Characterization studies were performed by using Fourier transform infra red (FTIR), which showed the introduction of carboxylic group in the structure the modified sugarcane bagasse (MSB). Batch study revealed the influence of pH, time, initial concentration of metal ion on adsorption capacity. The data showed an extremely good fit to Langmuir isotherm model from which the maximum adsorption capacity estimated reached 28.17 mg/g at optimum pH 5.5. Fixed bed column study using the adsorbent MSB confirmed that the breakthrough curves of the adsorption processes were dependent on bed height, initial concentration and flow rate. Linear regression analysis of the data demonstrated that Yoon-Nelson kinetic models were appropriate to explain the breakthrough curves.<br>Nghiên cứu đã thực hiện biến tính hóa học vật liệu bã mía bằng acid citric và đánh giá khả năng hấp phụ ion Cu(II) trong nước của bã mía (SB) trước và sau biến tính axit citric. Khảo sát cấu trúc vật liệu thông qua phổ hồng ngoại FTIR cho thấy các nhóm chức carboxylic có khả năng hấp phụ kim loại xuất hiện trong vật liệu biến tính. Thí nghiệm mẻ đánh giá sự ảnh hưởng của pH, thời gian và nồng độ của vật liệu tự nhiên và biến tính đến khả năng hấp phụ ion Cu(II). Kết quả của thí nghiệm mẻ phù hợp với mô hình Langmuir với khả năng hấp phụ cực đại đạt 28,17 mg/g tại nồng độ pH tối ưu là 5,5. Kết quả thí nghiệm trên mô hình cột cho thấy đường cong thoát của quá trình hấp phụ của vật liệu biến tính và chưa biến tính phụ thuộc và chiều cao lớp vật liệu, nồng độ ion Cu(II) ban đầu và vận tốc dòng chảy qua cột. Các dữ liệu thu nhận được từ thực nghiệm phù hợp với mô hình động học Yoon-Nelson.

Colloid-borne Heavy Metals in the Drainage Gallery of an Abandoned Zn-Pb-Ag Mine (in German). The colloid inventories and the colloid-borne heavy metals in the Rothschönberger Stolln adit, the main drainage gallery of the Freiberg, Germany, mining district, were investigated. This adit runs from Freiberg to the village of Rothschönberg, where it flows into the river Triebisch, a tributary of the river Elbe. The water of the adit is a typical mine water from a flooded ore mine. The main reason for choosing the Rothschönberger Stolln adit for colloid investigations was that ample knowledge concerning the origin of the water and the geology of its catchment area exists. The aim was to characterize the colloids at the mouth of the adit and to elucidate if important contaminants occur in a colloid-borne form. A colloid concentration of about 1 mg/L was found. The particles have a size of 50 to 150 nm. They primarily consist of iron and aluminum oxyhydroxide and carry trace elements such as Pb, As, Cu, Y, La. The contaminants Pb and As are almost entirely colloid-borne. Colloids can have both a retarding and a stimulating influence on the transport of contaminants. The existence of colloids should be taken into account if mine waters flow to the biosphere or if mine waters are to be purified by permeable reactive barriers.

Colloid-borne Heavy Metals in the Drainage Gallery of an Abandoned Zn-Pb-Ag Mine (in German). The colloid inventories and the colloid-borne heavy metals in the Rothschönberger Stolln adit, the main drainage gallery of the Freiberg, Germany, mining district, were investigated. This adit runs from Freiberg to the village of Rothschönberg, where it flows into the river Triebisch, a tributary of the river Elbe. The water of the adit is a typical mine water from a flooded ore mine. The main reason for choosing the Rothschönberger Stolln adit for colloid investigations was that ample knowledge concerning the origin of the water and the geology of its catchment area exists. The aim was to characterize the colloids at the mouth of the adit and to elucidate if important contaminants occur in a colloid-borne form. A colloid concentration of about 1 mg/L was found. The particles have a size of 50 to 150 nm. They primarily consist of iron and aluminum oxyhydroxide and carry trace elements such as Pb, As, Cu, Y, La. The contaminants Pb and As are almost entirely colloid-borne. Colloids can have both a retarding and a stimulating influence on the transport of contaminants. The existence of colloids should be taken into account if mine waters flow to the biosphere or if mine waters are to be purified by permeable reactive barriers.

The potential of non-viable Azalia filiculaides for the removal of Cu and Ni from aqueous solutions and the possibility of scaling up existing lab scale Azalia column systems was investigated. The effects of factors such as metal starting concentration, pH and two metals in solution on the removal of Ni and Cu from aqueous solution by dried and crushed Azalia biomass were studied in batch systems. Aqueous solutions of Ni with starting concentrations between 1000 and 2000J.lmolll gave the most efficient Ni removal by Azalla biomass. For Cu the optimum starting concentration for adsorption was 50J.lmol/l. The adsorption capacity of both eu and Ni increased as the starting pH of the sorption media increased. The optimum pH for Ni adsorption was found at pH 7 and for Cu, at pH 5. - Awlla biomass had a higher. maximum binding capacity (qrnax) for Cu than for Ni at pH 5. The removal of both Cu allct Ni showed little or no variation with the presence another metal in solution. Kinetic studies show that both Cu and Ni adsorbed rapidly onto the Azalia biomass. The removal of Cu and Ni from aqueous solutions using non-viable Azalia biomass was investigated in a lab scale fixed-bed column and an upscaled 4L column system. The nonviable Azalla filiculaides biomass when dried and used in a column for adsorption of Cu and Ni showed good physical stability under many different conditions. Preparation of the biomass before it could be used in the columns was very simple and did not involve any significant pretreatment steps. Prolonged exposure to UV light decreases Azalia biomass capacity for Ni and Cu adsorption. Column adsorption of Cu and Ni from aqueous solutions was successfully upscaled approximately 100 times. Relative to the lab scale column, the 4L column performed better for the uptake of Cu and Ni per gram of biomass. The larger column was also able to operate at relatively higher flow rates. The biomass showed good reusability with little change in the amount of Ni adsorbed in 10 consecutive cycles. Electron micrographs showecf little or no change in the physical structure and integrity of the Azolla biomass after exposure to mineral acids, Ni solution and high flow rates over 10 consecutive adsorption and desorption cycles. As much as 80% Ni and 70 % Cu was recovered when desorption profiles were generated using O.lMHCI as a desorption agent. The 4L column system was also tested using a highly concen~rat:~ Ni plating bath solution.(Nicrolyte 1). Only 18 % of the Ni could be removed from the expended Nicrolyte 1 pla~Jng solution after treating only 25L, indicating that Azolla biomass is more suited for removal of metals from more dilute industrial effluents.

Metals sorption in soils is influenced by several factors, including pH, ionic strength, the presence of ionic composition or organic ligands, total amount of metals, and adsorbent loading. These conditions should be considered when evaluating metal sorption capacity of soil material or when applying laboratory results to field conditions. Metal sorption experiments were conducted on Bertie sandy and Starr-Dyke clay loam soils from long-term field studies in which soils received annual applications of copper-rich pig manure for 16 years. Adsorption of Cd, Cu, Pb, and Zn as affected by different background electrolytes at various concentrations was investigated. Electrolytes were Na+, Ca2+, or Al3+ in perchlorate solution, and their concentrations ranged from 0.001 to 0.5 molc L-1. Increasing ionic strength decreased metal adsorption capacity. Electrolyte cation composition had a greater effect on adsorption than did electrolyte concentration. The order of sensitivity to cation composition of the electrolyte was Zn > Cd > Cu > Pb, and this effect was greater in Bertie sandy loam than Starr-Dyke clay loam soils. Little difference in Cu and Pb adsorption was observed between Na+ and Ca2+ in background solution. Most added Cu was adsorbed at low concentrations regardless of pH, but at high concentrations Cu sorption was strongly related to solution pH. Increases in pH resulted in greater Cu sorption due to pH-dependent negative charges and precipitation. The USEPA recommends that soil systems receiving high metal loading rates be maintained at pH 6.5 or above because of the increased metal adsorption. However, pig manure applications to the Bertie soil resulted in greater Cu in soil solution than in control (no manure) soil at pH > 6.5 due to soluble organic matter. Using the Langmuir equation to determine adsorption maxima for soil systems does not always give adequate estimates of adsorption and values from the equations are highly dependent upon soil environmental parameters. Given the limitations in prediction of adsorption maxima, and given that the amount of nonsorbed metal is as important as the adsorbed amount, the isolines of metal remaining in soil solution were provided with a given set of soil environmental factors.<br>Ph. D.

Abstract In this thesis oxidation of a pure and alloyed Cu surface was studied using density functional theory based calculations. The mechanism and energetics behind experimentally observed missing row reconstruction on a pure Cu(100) surface were studied. Examination of the formation of the missing row was approached by studying the profitableness of vacancy formation to the surface at oxygen coverages below and equal to 0.5 ML. However, an ideal surface was in all cases more favourable in energy than vacancy included structures. Therefore an additional Cu atom was added to the simulation cell to promote vacancy formation. A consequence of this on-surface Cu addition was the identifying of a new energetically favoured Cu-O-Cu chain formation. This newly identified structure is a possible transition state in the path from an ideal surface to a reconstructed one. Copper(I)oxide formation through sub-surface adsorption was examined on a reconstructed Cu(100) surface. At low O coverage on-surface adsorption was found to be much more favoured than adsorption on sub-surface sites. However, when coverage increased to 0.75 ML structures with both on-surface and sub-surface adsorbates possessed the lowest energy. Furthermore, the diffusion barriers to the sub-surface adsorption sites were low. Both these facts support the conclusion that the transition from the reconstructed missing row structure to the copper(I)oxide takes place without any large energy effort. The adsorption induced segregation of copper on a Ag/Cu(100) surface was studied by calculating the surface energies of slabs where the silver layer was positioned at different depths with varying O coverage. In addition, the segregation energies were also calculated with two Ag compositions. It was discovered that without oxygen adsorbates silver atoms lying on top of the surface were favoured but the surface segregation probability of Cu increases with increasing O coverage. The same calculation procedure was expanded to study the segregation probability of five additional alloy metals with a Cu surface. Without oxygen present Mg, Al and Zn possess a weak tendency to segregate to the surface, however, V and Cr prefer to stay in the bulk. The addition of oxygen adsorbates on the surface causes the segregation of all the dopants to the top of the surface. With the Al dopant the effect of the surface orientation and the oxygen coverage were also studied. The bonds between adsorbates and the surface were strongest with the densest surface, (111), and weakest with the most opened surface, (110). Furthermore, the enrichment probability was largest in the case of the (111) surface and lowest with the (110) surface. Probability increased with increasing oxygen coverage<br>Tiivistelmä Tässä väitöstyössä on tutkittu puhtaan ja seostetun kuparipinnan hapettumista tiheysfunktionaaliteoriaan perustuvilla laskuilla. Kokeellisesti Cu(100) pinnan on havaittu rekonstruoituvan hapen vaikutuksesta. Rekonstruoitumisen aikana ideaalisesta pinnasta irtoaa joka neljäs pintakuparirivi ja muodostuu niin kutsuttu missing row- rakenne. Tämän rakenteen muodostumismekanismia ja muodostumiseen kuluvaa energiaa tutkittiin vertaamalla pintavakansillisten rakenteiden pintaenergioita vastaaviin ideaalipinnan arvoihin vaihtelevalla happipeitolla. Koska ideaalipinta oli kaikilla peittoasteilla energeettisesti suotuisampi kuin vakanssirakenne, yksittäisiä kupariatomeja lisättiin pinnalle stabiloimaan vakanssirakenteita. Kuparilisäyksen seurauksena löydettiin uusi energeettisesti edullinen Cu-O-Cu ketjurakenne. Tämä rakenne on mahdollinen ideaalisen ja rekonstruoituneen pinnan välinen siirtymätila. Kupari(I)oksidin muodostumista pinnanalaisen happiadsorption kautta tutkittiin rekonstruoituneella Cu(100) pinnalla. Pienillä happi-peittoasteilla pinnanpäällisen adsorption havaittiin olevan huomattavasti suotuisampaa kuin pinnanalaisen adsorption. Kuitenkin happi peiton kasvaessa 0,75 ML:iin rakenteet, joissa oli adsorbaatteja sekä pinnan alla että päällä, tulivat muita suotuisimmiksi. Myös lasketut energiavallit hapen diffuusiolle pinnalta pinnan alle olivat hyvin pieniä. Kaikki tulokset viittaavat siihen, että rekonstruoitunut Cu(100) pinta hapettuu helposti kupari(I)oksidiksi. Happiadsorption aikaansaamaa kuparin rikastumista (segregaatio) hopeakupariseosmetallin pinnalle tutkittiin laskemalla vaihtelevilla happipeitoilla pintaenergiat kuparipinnoille, joissa ensimmäinen, toinen ja kolmas kuparikerros oli korvattu hopealla. Myös segregaatioenergiat laskettiin kahdella eri seoskoostumuksella. Saatujen tulosten mukaan ilman happiadsoptiota hopea segregoituu pinnalle, kun taas hapen peittoasteen kasvaessa kupari rikastuu pinnalle. Samaa tutkimustapaa käytettiin myös tarkasteltaessa viiden muun seosmetallin segregaatiotodennäköisyyttä kuparipinnalla. Ilman pintahappea magnesiumilla, alumiinilla ja sinkillä oli heikko taipumus rikastua pinnalle, kun taas vanadium ja kromi pysyivät syvemmällä metallissa. Sen sijaan happea lisättäessä kaikki tutkitut seosmetallit pyrkivät siirtymään kohti pintaa. Myös hapen peiton sekä pintaorientaation vaikutusta segregaatioon tutkittiin hopeakuparipinnalla. Sekä happiadsorbaattien ja pinnan välinen sidos että segregaatiotodennäköisyys oli sitä voimakkaampaa, mitä tiheämmästä pinnasta oli kyse. Segregaatiotodennäköisyys kasvoi pinta-adsorption lisääntyessä

Elevated levels of arsenic and other heavy metals like copper, aluminum, zinc, and selenium in drinking water are found to have deleterious effects on human health. Hence, finding methods for reducing their levels is critical. Iron-coated limestone is used as an adsorption material for the removal of heavy metals from drinking water. Removal of heavy metals by native or uncoated limestone was also observed and used for comparison to and evaluation of the improvement in removal efficiency from the ironcoated material. The removal efficiency with limestone was studied for different concentrations of heavy metals. Kinetic studies were done to determine the decrease in heavy metal concentration as a function of time using limestone. Inductively coupled plasma spectroscopy was used for metal analysis. The effective removal rate of copper and aluminum was found to be four hours and one hour, respectively. This method of removal by using limestone is cost effective, eco-friendly, and hence, of great potential importance for heavy metal removal. Iron-coated limestone is used as an adsorption material for the removal of heavy metals from drinking water. This project will investigate techniques to improve removal efficiency of heavy metals using limestone-based material through adsorption. This research will assist in the development of a granular adsorbent product that will remove metals and that can be manufactured and sold for use at the drinking water source, at point-of-use, or at point-of-entry. Limestone is readily available and its use for metals removal is relatively inexpensive. The technology can be adapted to small, rural water supply systems. Benefits of this research will include a low-cost treatment technology for source reduction that will reduce select metals to below drinking water standards.

The primary goal of the work discussed in this thesis was to assess the capability of cheap, readily available ligands, e.g. pyridines and amines, to produce new coordination compounds, primarily with copper, that could lead to the development of novel materials for gas adsorption. Chapters 1 and 2 introduce the topic and methods respectively, results are contained within chapters 3-6. Chapter 3 describes the synthesis, polymorphism and solid-gas reactions of [CuCl₂(RPy)₂] and (RPy-H)[CuCl₄] (RPy: R = 4-CO₂H, 4-CONH₂, 3-CONH₂). The polymeric [CuCl₂(RPy)₂] compounds appear blue, while the equivalent (RPy-H)[CuCl₄] salts appear yellow or green depending on the geometry of the [CuCl₄]²⁻ ion. Exchange between the two types of compound is possible through the gain and loss of HCl, although the exact mechanism and what causes the observed differences in reaction is uncertain. [CuCl₂(RPy)₂] compounds could be developed further into porous materials through the use of simple tris(pyridine) ligands. Chapter 4 discusses a facile synthetic method for [Cu₄(μ⁴-O)(μ²-Cl)6(RPy)₄] compounds via the oxidation of CuCl in the presence of [CuCl₂(RPy)₂]n (RPy: R = 4-Me, 4-NH₂, 4-NMe₂). The production of the [Cu₄(μ⁴-O)(μ²-Cl)6(RPy)₄] cluster only seems to occur for compounds where the [CuCl₂(RPy)₂] complex is non-polymeric or at least weakly polymeric. Only one porous [Cu₄(μ⁴-O)(μ²-Cl)6(RPy)₄] compound is known with 1,4-diazabicyclo[2.2.2]octane, but there is potential for others to be discovered. However, these compounds are not as stable as other compounds that might be used for gas adsorption and are better suited for catalysis applications. Chapter 5 focuses on the copper and zinc coordination chemistry of amino acids with general formula CO₂H-(CH₂)n-NH₂ (where n = 1-5 and 7). Amino acids are a good potential ligand for CO₂ capture given their similarity with monoethanolamine: the most common chemical used in industrial technologies. However, their flexibility and propensity to form zwitterions means that the majority of compounds produced were adducts of copper halides, and those which were not appeared too dense for application in CO₂ adsorption. The copper halide adducts showed similar HCl/HBr gas uptake as the [CuCl₂(RPy)₂] compounds in chapter 3, although the reverse reaction was much slower with very little change observed over several months. Lastly, chapter 6 details the novel coordination compounds created using Cu and a combination of various benzoic acid based and pyridine-based ligands. Most of the novel compounds have only been structurally characterised and no general conclusions can be made about their structures due to the lack of data. One compound made with 4-hydroxybenzoic acid and pyrazine in methanol showed promise for methanol adsorption, however the compound could not be made reliably or quantities large enough to study the phenomenon further.

The main objectives of this project are the synthesis and redox- or photo-active modification and CO2 adsorption studies of metal-organic frameworks (MOFs) based on Cu3-pyrazolate secondary building units (SBUs). Trinuclear copper(II) complexes of the formula [Cu3(µ3-O)(µ-4-R-pz)3X3]z have been studied extensively due to their redox, magnetic and catalytic properties. In earlier work, we have shown that trinuclear copper(II) complexes of the formula [Cu3(µ3-O)(µ-4-R-pz)3X3]z pz = pyrazolato anion; R = H, CH(O), Cl, Br and NO2; X = Cl, NCS, CH3COO, CF3COO and pyridine – can be oxidized to the corresponding z+1, formally CuII2CuIII, species. In this project, fourteen (14) new copper-pyrazolate complexes of varying nuclearities (Cu3, Cu6, Cu7 and Cu12), terminal ligands (-NO2, py, -N3, -Cl) and bridging ligands (4-Cl-pzH and 4-Ph-pzH) have been synthesized. Efforts have been made to prepare MOFs based on the Cu3(µ3-O)-SBUs. While attempting to design the most suitable SBU for redox-active MOF construction, it was found that the one-electron oxidation of the all-CuII complex [Cu3(µ3-O)(µ-pz)3(NO2)3]2–, [8]2-, was achieved at redox potential more cathodic than any other Cu3(µ3-O)-complexes studied in our laboratory. The mixed-valent compound, [Cu3(µ3-O)(µ-pz)3(NO2)3]–, [8]-, the easiest accessible CuII2CuIII species known to date, was characterized spectroscopically. Compound [8] and analogous [11] release NO almost quantitatively upon the addition of PhSH or acetic acid. The system is catalytic in the presence of excess nitrite. Before embarking on the study of photo-active MOFs, a simpler model compound – a dimer of trimer [{Cu3(µ3-OH)(µ-4-Cl-pz)3(py)2}2(µ-abp)](ClO4)4 [21], where abp = 4,4’-azopyridine, was synthesized and its photochemistry was studied. The absorption spectra recorded before and after irradiation indicated a structural change. Two dimensional (2D) and three dimensional (3D) materials with {[Cu3(µ3-OH)(µ-4-R-pz)3]2+}n SBUs where R = Ph or Cl , which can potentially undergo cis/trans-isomerization, have been prepared during this project. A Phenyl substituent at 4-position on the pyrazole ligand leads to the formation of new class of 2D sheets. Three new 3D porous MOFs based on {[Cu3(µ3-OH)(µ-4-Cl-pz)3]2+}n SBUs have interpenetrated- lattice structures and are capable of adsorbing CO2 selectively. Compounds FIU-1 and FIU-3 also exhibit hysteretic sorption-desorption profiles indicating the flexibility of the MOFs upon adsorption. Compound FIU-1 demonstrates the usefulness of a hexanuclear CuII -pyrazolate moiety as an SBU for generating 3-fold interpenetrated 3D polymeric network. Complexes FIU-2 and FIU-3 have novel 3-fold interpenetrating 3D hexagonal framework structures. Compound FIU-2 crystallizes in the monoclinic crystal system with the P21/c space group, whereas FIU-3 crystallizes in triclinic space group P . Both structures contain Cu3-SBUs connected by the linkers through the Cu-termini.

碩士<br>大葉大學<br>環境工程學系碩士班<br>98<br>This study employed coffee residues to remove copper ions from wastewater. The effects of copper concentration, coffee residues dosage, ionic strength and temperature on adsorption of copper ions by coffee residues were evaluated. Pseudo first-order, pseudo second-order, intraparticle diffusion and Bangham models were adopted to evaluate experimental data and thereby elucidate the kinetic adsorption process. Additionally, this study used the Langmuir, Freundlich, and Redlich-Paterson isotherms to describe equilibrium adsorption. The adsorption percentage of copper ions increased as coffee residues dosage and temperature increased. Conversely, the adsorption percentage of copper ions decreased as copper concentration increased. The pseudo second-order model best represented adsorption kinetics. Based on the regressions of intraparticle diffusion and Bangham models, experimental data suggest that the adsorption of copper ions onto coffee residues involved intraparticle diffusion, but that was not the only rate-controlling step. The equilibrium adsorption of copper ions is best fitted in the Redlich-Paterson isotherm. The capacity of coffee residues to adsorb copper ions was 7.9 mg/g (25℃). The enthalpy (ΔH0) and entropy (ΔS0) were 20.681 kJ/mol and 213.3 J/mol K, respectively. The values of enthalpy and entropy both indicate that the adsorption of copper ions onto coffee residues was a physisorption process. The exhausted coffee residues were regenerated by HNO3 extraction and the re-adsorption efficiency was approximately 50%.

碩士<br>國立臺灣科技大學<br>工程技術研究所<br>98<br>This research aims to study the absorption and conversion of ethanol on catalyst supported on SiO2- and CeO2- in order to understand ethanol reforming reaction. The CeO2 was loaded on the SiO2 via incipient wetness impregnation, and its properties was compared with the CeO2 prepared by homogeneous precipitation method. The catalysts were characterized and examined by N2 physisorption, X-ray powder diffraction, temperature programmed reduction, ethanol pulse chemisorption, temperature programmed desorption and ethanol pulse reaction. Higher ethanol absorption of CeO2(HSA) was achieved by loading 0.2wt% Cu. During the process of temperature programmed reduction, the incorporation of the Cu promoted the decomposition of the surface species of catalyst. The loading of Cu also enhanced the ethanol conversion as indicated in the ethanol pulse chemisorption experiments suggesting that the catalyst system is feasible to operate with lower temperature.

M.Sc.<br>Inorganic pollutants like heavy metals are some of the major water pollutants worldwide. They are toxic and in some cases carcinogenic even at low concentrations. Their removal from industrial aqueous solutions, wastewater and hydrometallurgical process solutions prior to their release to the environment is necessary for a healthy biosphere which includes human beings, aquatic life and plants. There are several technologies used to remove metals such as Cu, Co, Zn, Hg from water. These include among others, ion exchange, membrane filtration, activated carbon, electrochemical treatment, chemical precipitation, reverse osmosis, coagulation and flocculation. Although they have been used in the removal of metal pollutants from water, these technologies produce high quantities of sludge. They are also expensive to operate and need well trained personnel to operate large chemical plants. Since current metal removal techniques have limitations, a need exists for the development of environmentally friendly and cost effective techniques for the removal of metal ions from aqueous media. The focus of this research project is on the use of micro-organisms as biosorbents for copper and cobalt pollutants in aqueous solutions. The experimental work was carried out on a laboratory scale and a summary of our findings is presented as follows: Synthetic sulphate solutions of copper and cobalt were prepared using CuSO4. 7H2O and CoSO4. 5H2O powders. Concentrations of 0.002 M, 0.07 M and 0.2 M copper and cobalt ions in solution were used as test synthetic solutions for our experiments. Mixed strains of bioleaching bacteria were sourced from Mintek (Randburg, South Africa) to test the viability of this research project. This consortium contained Acidithiobacillus caldus, Leptospirillum spp, Ferroplasma spp and Sulphobacillus spp. These bacteria were able to remove up to 55% copper and 25% cobalt from low concentrated copper and cobalt sulphate solutions with 69% and 58% removal demonstrated in the case of mine effluents emanating from metallurgical operations. Different strains of micro-organisms (bacteria) were isolated from mine dumps and mine operation effluents and soil from the Palabora Mining Company in Limpopo, a northern province in South Africa and Nigel Town in the Gauteng Province. The isolated bacterial strains were then identified using PCR analysis and strains from the Bacillus genre were found to be predominant. Shewanella spp was also present. Pseudomonas spp was isolated using Pseudomonas agar base. These bacteria were then cultured at different species-specific culture conditions and their capabilities to remove copper and cobalt ions first from synthetic solutions and subsequently from mine effluents emanating from metallurgical operations were tested. In the first stage of biosorption experiments, factors that affect biosorption mechanisms which include, solution concentration, biomass concentration, pH, contact time and the presence of other metal co-ions were investigated. A decrease in the amount of metal sorbed as solution concentrations increased was observed with all the bacterial strains. An increase in metal sorption was also observed when biomass concentration was increased. The pH was found to be a species dependant parameter.

碩士<br>大葉大學<br>環境工程學系碩士班<br>99<br>This study employed the modified cellulose to adsorb copper ions from aqueous solution. The surface modified agents included citric acid, phosphate acid and sulfate acid. The effects of modified agent concentration (0.3, 0.6, 0.9 and 1.2 M), modified temperature (90, 120, 150 and 180℃), modified time (60, 120, 180 and 180 min) were evaluated for the adsorption of copper ions onto the surface of modified cellulose. Moreover, the influences of pH (3, 4 and 5), modified cellulose dosage (0.5, 1.0 and 2.5 g/L), copper ions concentration (10, 20 and 40 mg/L) and temperature (15, 25 and 35℃) were also investigated in this work. The surface characteristics of raw and modified cellulose were determined by SEM, BET, FTIR and zeta potential. The specific surface area of modified cellulose was greater than that of raw cellulose; additionally, the zeta potential of modified cellulose was lower than that of raw cellulose. Bangham's equation, pseudo- first -order kinetic model, pseudo-second-order kinetic model and intrapariticle diffusion model were used to simulate the kinetic adsorption; moreover, Langmuir, Freundlich, Redlich-Paterson, Dubinin-Radushkevich and Temkin isotherms were employed to simulate the equilibrium adsorption. The experimental results indicated the adsorption percentage of copper ions onto the surface of modified cellulose increased with pH and cellulose dose increasing. Experimental results reveal that the affinity of modified cellulose for copper ions increased as temperature increased, suggesting that adsorption of copper ions onto modified cellulose is endothermic. Based on analyses of thermodynamic parameters, adsorption of copper ions onto modified cellulose was driven by a physisorption process. The ΔH0 and ΔS0 were 11.85 kJ/mol and 130 J/mol.K, respectively. Activation energy (Ea), ΔH0, and ΔG0 suggested that adsorption of copper ions onto modified cellulose was via physisorption.

碩士<br>國立雲林科技大學<br>化學工程與材料工程系碩士班<br>100<br>In this study, poly-γ-glutamate-apatite (PGA-AP) particles were prepared for the adsorption of copper ions. They were synthesized by coprecipitation between calcium nitrate and diammonium phosphate in poly-γ-glutamate (PGA) solution with different feed ratios of PGA to calcium nitrate and diammonium phosphate. The theoretical weight ratios of poly γ-glutamate to apatite (PGA/AP) for PGA-AP particles are 1:20 (G1H20), 1:40 (G1H40) and 1:60 (G1H60). The PGA-AP particles were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS), thermo gravimetric analyzer (TGA) and particle analyzer. Adsorption experiments were carried out to investigate the effects of different adsorption parameters, such as different PGA/AP weight ratios, temperature and pH, on the adsorption capabilities of PGA-AP particles. The formation of PGA-AP particles were confirmed by the phosphate bands and amide bands at FTIR spectra. The XRD spectra of PGA-AP particles are similar to that of hydroxylapatite. The EDS shows that the Ca/P mole ratios of G1H20, G1H40 and G1H60 are 1.62, 1.54 and 1.72, respectively. The actual PGA/AP weight ratios of G1H20, G1H40 and G1H60 are 1:15, 1:24 and 1:44, respectively. The particle sizes of G1H20, G1H40 and G1H60 are 79.7±1.6、88.5±0.8 and 92.8±2.3 nm, respectively. The results of adsorption experiments show that initial adsorption rate is rapid and equilibrium is attained at 60 minutes. The adsorption capabilities increase with the increases of the PGA/AP weight ratios, temperature and pH. Kinetic data are well fitted by a pseudo second-order model and the equilibrium data are analyzed by Langmuir model very well with high correlation coefficient. From the kinetic data, G1H20 has the largest adsorption capability than those of G1H40 and G1H60. From the Langmuir isotherms, the maximum adsorption capacity of G1H20 towards copper ions is 85.47 mg/g when the experiments were carried out at 60℃ and pH 6. Thermodynamic parameters ΔH, ΔS and ΔG have been calculated. Positive value of ΔH and negative value of ΔG show endothermic and spontaneous nature of sorption, respectively.

碩士<br>大同工學院<br>化學工程研究所<br>87<br>The adsorption and desorption characteristics of CO on the activated carbon impregnated with Copper (I) Chloride in HCl solution were measured by fixed-bed runs. CuCl impregnated carbons were characterized by N2 adsorption, SEM, and X-ray. It was found that the impregnation of CuCl effectively increased CO adsorption. The effects of CO concentration, adsorption temperature, impregnant amount, impregnated HCl concentration, and particle sizes were also investigated on these carbons. The CO adsorbing capacity of impregnated activated carbon increased with the increase of CO concentration, impregnant amount, and impregnated HCl solution. The amounts of CuCl impregnated on the surface of activated carbon were affected by the impregnated HCl concentration, i.e., the solubility of CuCl in HCl solution. Reversible adsorption/desorption characteristics were elucidated in the experiment. Adsorption isotherms of CO were measured and correlated by four isotherm equations. It was found that Dubinin-Radushkevich equation can fit the equilibrium data within 25% under the operating ranges.

碩士<br>國立中央大學<br>環境工程研究所碩士在職專班<br>97<br>This study was to develop a high efficiency and low cost modified diatomite absorbent for copper removal from wastewater. The diatomite was modified and activated by three ways, which were acid etching, alkaline etching and iron hydroxide coating. According to the results of isotherm adsorption test, the efficiencies of copper adsorption by alkaline etching and iron hydroxide coating diatomite were better than those of acid etching and original diatomite. The adsorption capacity of copper by modified diatomite was fitted to Langmuir adsorption model. After the evaluation of removal efficiency and economic feasibility, alkaline modified diatomite was selected to run column and pilot scale adsorption tests. The results of kinetic adsorption test showed that the alkaline modified diatomite could enhance copper adsorption capacity and removal efficiency as compare to that of the original diatomite. The results of laboratory scale column tests revealed that the copper removal efficiency was greater than 98% before 1000 bed volumes of wastewater passed through. The copper removal efficiencies of 65~84% were achieved by pilot scale treatment facility for treating real wastewater containing 3 ppm of copper. Therefore, the utilization of alkaline modified diatomite could further reduce the copper concentration and was feasible to meet the more restricted discharge criteria.

碩士<br>國立臺北科技大學<br>化學工程與生物科技系化學工程碩士班<br>106<br>Epoxy gels were prepared from polyethylene glycol diglycidyl ether (PEGDE) cured with various amine compounds, such as diethylene triamine (DETA), 3,3-diaminodipropylamine (NSPD), and 2,4,6-tris-(dimethylaminomethyl) phenol (DMP-30). The adsorption of Cu (II) ions in aqueous sulfate solution dependent on the compositions and morphologies of the epoxy gels have been investigated. It was found that the water uptake was approximately 370%, and the adsorption capacity of Cu (II) ions was 45.4 mg/g of the epoxy gel synthesized from the mixture of PEGDE and DETA at equal molar ratio in water. The equilibrium adsorption capacity of Cu (II) was also dependent on the temperature and pH value of the solution, which increased to 55.5 mg/g at 25°C and pH=5.

碩士<br>國立陽明大學<br>環境與職業衛生研究所<br>107<br>Recently, much attention has been given to heavy metal soil pollution, much of which comes from wastewater. Over time, most pollution of agricultural land in Taiwan has come from industrial waste which came as a result of industrial development. Therefore, wastewater containing heavy metal contaminants has become a prominent environmental issue. These days, people tend to spend most of their time indoors. As a result, microbial contamination has become a more pressing issue. Due to copper’s lower cost than silver and its recyclability from wastewater, copper has become the most studied antibacterial material. In this study, we will focus on the adsorption of copper in wastewater by chitosan absorbent, and the antibacterial activity of chitosan composites after absorbing copper. We will also be comparing the different absorbent efficiency and antibacterial activity between the chitosan (CS) and chitosan-TiO2 (CST) composites. The CS and CST composites are characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), nitrogen adsorption/desorption isotherm at 77K, Fourier Transform Infrared Spectrometer (FT-IR), Thermogravimetric Analysis (TGA). The adsorption ability was tested by the spectrophotometry-Bis(cyclohexanone)oxaldihydrazone (BCO) method in the lab along with a series of copper nitrate solution of varying concentrations. Antimicrobial activity was evaluated by the zone of inhibition (ZOI) assay against E. coli (Gram-negative) and S. epidermidis (Gram-positive). The results show the best Qt was the condition CS with 3% glutaraldehyde and exchange with ammonia solution with 300 ppm initial concentration, which of the Qt is 30.73 mg/g. All of the samples had antimicrobial properties. Respectively, the antimicrobial efficacy was affected by the copper ion more than the TiO2 and glutaraldehyde. The Qt results of adsorbing the 17636 mg/L Cu2+ from industry were about 330 mg/g, the Qt after dilution 50 times were about 10 mg/g, and the ZOI area of these two concentration were 50 times difference. The cost-benefit analysis showed that the cost of our materials were about 70 times more expensive than the treatment the industry is using now. However, there may be lower costs possible in treating polluted sludge. The produced material cost every year was about 1.7 billion NTD. With the results from our experiments, we found that the composites showed a good removal efficiency on copper ions. This indicates that the CS/CST composites after absorption demonstrated excellent antimicrobial activity, and could solve the copper ion pollution problem in wastewater as well as improving the air quality as a result of killing microbes.

碩士<br>國立雲林科技大學<br>環境與安全工程系碩士班<br>94<br>In this study, commercial Multi-walled carbon nanotubes (MWCNTs) were modified with acids and oxidants like H2SO4, HNO3, KMnO4 and NaOCl and applied to aqueous copper (Ⅱ) and cadmium (Ⅱ) adsorption. Their physicochemical properties were investigated by Zeta-potential, TGA, FTIR, HR-TEM, and acid-base titration measurement. The results in the modified method demonstrate that oxidation steps can reduce tubes the diameter and length using HR-TEM to observe. Oxidized treatment method not only opens the nanotube tips but also promotes the formation of densely packed network. By measuring the zeta potential function by difference pH, while zeta potential equals to zero point, pH value decreased with oxidized and acidic treatment methods as follow the sequence of KMnO4, NaOCl, HNO3, and H2SO4. Moreover, the above results indicated the amounts of functional groups as the negatively charged surfaces increased when oxidized and acidic treatment methods were used. In FTIR observation, the modified MWCNTs with oxidation method showed many functional groups, such as hydroxyl (-OH) 3400~3200 cm-1, 1560 cm-1, 1200 cm-1, carboxyl (-COOH) 2400 cm-1, 1700 cm-1, 1200 cm-1 on the MWCNTs. These functional groups attached on the surfaces of the MWCNTs improve their adsorption capability of copper (Ⅱ) and cadmium (Ⅱ) in solution. The adsorption experimental results showed that copper (Ⅱ) and cadmium (Ⅱ) adsorption capacities increased due to the more adsorption functional groups when using KMnO4 or NaOCl as oxidants to treat MWNTs, especially in lower pH. It was found that the adsorption isotherm followed both Langmuir and Freundlich models. However, the Langmuir model gave a better fit to all adsorption isotherms than Freundlich model. The kinetics of adsorption of copper (Ⅱ) has been tested using pseudo-fist-order and pseudo-second-order models. Results showed that the adsorption of copper (Ⅱ) from aqueous solution onto MNCNTs proceeded according to the pseudo-second-order model. The adsorption of the copper (Ⅱ) from aqueous solution was ehdothermic (�寒0 = 5.12 to 28.28 kJ/mol) and was accompanied by an increase in ehtropy (�巽0 = 0.035 to 0.109 kJ/mol K) and a decrease of Gibbs energy (�孱0 = -12.916 to -2.406 kJ/mol) in the temperature range of 280 – 320 K as commercial and modified MWCNTs.

碩士<br>國立成功大學<br>地球科學系<br>103<br>Lead (Pb) has been used extensively for many industrial purposes since the 19th century industrial revolution. However, Pb pollution can be found in various aquatic systems due to improper management of Pb contained waste or waste water. Being one of the major toxic inorganic pollutants, Pb can pose serious threat to living creatures at rather low concentration of 26–100 μg L-1. Once the blood lead (PbB) level of children exceeds 100 μg L-1, the central nervous system would damage and the body function may exhibit anomalous. Therefore, development of Pb remediation for drinking waters is critical and required. In this study, copper ferrite nano–particles (CuFe2O4) manufactured from industrial sludge were employed to evaluate aqueous Pb adsorption–desorption under various pHs, duration, initial Pb concentrations and solution matrix. Furthermore, a prospective study will be evaluated for Pb pre–concentration through the adsorption and desorption procedure. Our results indicated that the function of pH in sorption capacity of CuFe2O4 nano–particles was insignificantly, and reached the value of up to 90% at pH of 4.5. The adsorption kinetics fit well with pseudo–second–order model which suggests that Pb adsorption is a fast kinetics. Furthermore, the sorption isotherm fits well with the Langmuir model, and the maximum adsorption capacity of Pb was estimated to be 17.83 mg per gram sorbent at pH of 4.5 and temperature of 298 K. On the other hand, the ionic strength and coexisting cation showed negligible effect on Pb adsorption under seawater–like matrix. In desorption experiments, 0.005N HNO3 was evaluated as the best condition for Pb desorption with recovery of 75% in average, which enables Pb recycled and regenerated. In addition, Pb contents in CuFe2O4 were estimated 0.314±0.003 mg g-1 by digestion, and we infer that approximately 339.34±2.99 ng of Pb contribute to solution during desorption process. Overall, the novel low–cost fabricated CuFe2O4 from industrial sludge waste can be applied effectively for Pb remediation in aqueous solutions, not only deal with the danger of sludge waste and waste water, but also be considered as a reusable and cost–effective technique. On the other hand, through adsorption–desorption process, it demonstrates a potential application in Pb enrichment through simple operation procedure of adsorption and desorption.

碩士<br>明新科技大學<br>土木工程與環境資源管理系碩士班<br>101<br>Heavy metal pollution in industrial wastewater many species this thesis PCB surface treatment industry, in the manufacturing process microetch washing waste water, this single liquid waste of valuable metals (copper) recovery for the study. Study selection chelating resin of the resin adsorption of heavy metal ions are selective, high adsorption capacity, the resin can be easily separated from the original solution and can be reused after regeneration characteristics. If these heavy metals can be recycled, not only can solve the thorny issue of hazardous waste, while recycling of precious metals to achieve the purpose of and solution supply pressure and cost of raw materials. The main contents of the batch tests using the Dynamic Model of chelating resin adsorption resins for copper ions and then get optimum adsorption conditions and parameters, concentration liquid desorption choice, competitive adsorption of interfering ions, chelating type and concentration disturbance, to borrow from the ion exchange column tests using a resin adsorption on copper adsorption chromatography to achieve the purpose of separation of copper ions At first, raw water of pH 3.5 is artificially made to establish the optimized condition for various operation parameters and interference factors. The results show that 99.3% of copper ions can be adsorbed in 30 minutes to a first-order reaction of kinetic model for IRC748. The maximum amount of 57.47mg /g (0.905mol /g) of copper adsorption can be calculated by means of Langmuir equation. We have found that IRC748 desorption is most effective in a regeneration solution of 5% sulfuric acid, which need only about 60 minutes to accomplish 96.4% of copper desorption. The copper desorption of IRC748 is interfered by the presence of lead and nickel ions in solution. In our experiments the initial adsorption amounts of 1.11mmol/g on lead, 0.95mmole/g on nickel and 0.88mmole/g on copper without interference can be reduced to 0.26mmol/g, 0.42mmol/g and 0.43mmol/g with interference, respectively. Chelating agents also interfere with copper adsorption of IRC748. The weak chelating agent such as citric acid is ineffective for copper adsorption of IRC748. The strong chelating agent such as EDTA will reduce the capability of copper adsorption of IRC748. In our experiments the maximum adsorption of IRC748 was reduced to 32.8 mg/g and 9.2 mg/g in the EDTA/Cu ratios of 1/2 and 1/1, respectively. The experiments also showed that the adsorption/desorption ratio of IRC is constant in sodium sulfite. Finally, by batch adsorption experiment on the best conditions for the ion exchange column separation of copper ions experiments to chelating resin packed column flow rate of 10ml/min conducted during adsorption, and then at a flow rate of 5% sulfuric acid 2ml/min desorption eluent up more than 95% of copper separation. Keywords: chelating resin, ion adsorption, regeneration, through