This thesis explains a method based on the homogenisation of zeta potential charges on carbon supports for the production of hierarchical structured zeolitic composites. The modification of carbons’ surface chemistry allowed zeolite particles to be fixed to the support by electrostatic interactions. In order to achieve this, the size reduction of zeolite particles was carried out by two different methods: a) ball milling and b) a synthetic route to produce zeolite colloidal dispersions. Also, the seeding method, based on hydrothermal growth was compared. The prepared materials in this work were designed to be used in the sorption of cations, and to allow vitrification and thereby reduce the final adsorbent volume. Results showed that a large pollutant amount can be trapped using a lower volume of material reducing costs and final waste disposal. The zeolites used in this work were selected based on their low density framework and low Si/Al ratio. Synthetic zeolites A, Y and clinoptilolite were successfully produced. Natural clinoptilolite was also utilised in this work. Also, zeolite A was produced at nanometre scale following the clear solutions method. All materials were successfully incorporated onto supports to produce multimodal porosity materials. The hierarchical modification of natural clinoptilolite, following a straightforward and nonexpensive methodology, is one the most significant contributions of this work. Carbons are used as supports due to their high surface area, they can be obtained from low-cost sources such as agroindustrial wastes and carbons allow volume reduction if materials are vitrified at high temperatures. In this work, carbons were produced from corn cob and husk, sugar cane bagasse, cherry stones, date stones and hazelnut shells. The prepared composite materials were tested in the removal of toxic ions from water solutions: cobalt, copper and caesium ions were effectively removed from aqueous media. Adsorption experiments showed that the distribution of supported zeolite particles improved their uptake efficiency and capacity. The kinetic studies revealed an enhanced rate constant for carbon-zeolites composites in comparison with pure zeolites. Diffusivity results suggested that mass transfer characteristics are modified by using hierarchical porous materials; results showed that particle size or support nature can modify diffusion resistances, reducing intraparticle diffusion and accelerating the overall kinetic processes. Adsorption equilibrium data was correlated using Langmuir and Freundlich models.

by Tsui Wai-chu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 161-171). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abbreviations --- p.vii / Contents --- p.ix / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Literature review --- p.1 / Chapter 1.1.1 --- Metal pollution in Hong Kong --- p.1 / Chapter 1.1.2 --- Methods for removal of metal ions from industrial effluent --- p.4 / Chapter A. --- Physico-chemical methods --- p.4 / Chapter B. --- Biosorption --- p.7 / Chapter 1.1.3 --- Chitin and chitosan --- p.11 / Chapter A. --- History of chitin and chitosan --- p.11 / Chapter B. --- Structures and sources of chitin and chitosan --- p.12 / Chapter C. --- Characterization of chitin and chitosan --- p.17 / Chapter D. --- Applications of chitin and chitosan --- p.19 / Chapter 1.1.4 --- Factors affecting biosorption --- p.22 / Chapter A. --- Solution pH --- p.22 / Chapter B. --- Concentration of biosorbent --- p.24 / Chapter C. --- Retention time --- p.25 / Chapter D. --- Initial metal ion concentration --- p.26 / Chapter E. --- Presence of other cations --- p.26 / Chapter F. --- Presence of anions --- p.28 / Chapter 1.1.5 --- Regeneration of metal ion-laden biosorbent --- p.28 / Chapter 1.1.6 --- Modeling of biosorption --- p.29 / Chapter A. --- Adsorption equilibria and adsorption isotherm --- p.29 / Chapter B. --- Langmuir isotherm --- p.33 / Chapter C. --- Freundlich isotherm --- p.34 / Chapter 1.2 --- Objectives of the present study --- p.36 / Chapter 2. --- Materials and methods --- p.37 / Chapter 2.1 --- Biosorbents --- p.37 / Chapter 2.1.1 --- Production of biosorbents --- p.37 / Chapter 2.1.2 --- Pretreatment of biosorbents --- p.39 / Chapter 2.2 --- Characterization of biosorbents --- p.39 / Chapter 2.2.1 --- Chitin assay --- p.39 / Chapter 2.2.2 --- Protein assay --- p.40 / Chapter 2.2.3 --- Metal analysis --- p.41 / Chapter 2.2.4 --- Degree of N-deacetylation analysis --- p.43 / Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.43 / Chapter B. --- Elemental analysis --- p.43 / Chapter 2.3 --- Batch biosorption experiment --- p.44 / Chapter 2.4 --- Selection of biosorbent for metal ion removal --- p.45 / Chapter 2.4.1 --- Effects of pretreatments of biosorbents on adsorption of Cu --- p.45 / Chapter A. --- Washing --- p.45 / Chapter B. --- Pre-swelling --- p.46 / Chapter 2.4.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.46 / Chapter 2.4.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.46 / Chapter 2.5 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.48 / Chapter 2.5.1 --- Solution pH and concentration of biosorbent --- p.48 / Chapter 2.5.2 --- Retention time --- p.48 / Chapter 2.5.3 --- Initial metal ion concentration --- p.49 / Chapter 2.5.4 --- Presence of other cations --- p.49 / Chapter 2.5.5 --- Presence of anions --- p.51 / Chapter 2.6 --- Optimization of Cu2+，Ni2+ and Zn2+ removal efficiencies --- p.53 / Chapter 2.7 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden chitin A" --- p.53 / Chapter 2.7.1 --- Performances of various eluents on metal ion recovery --- p.53 / Chapter 2.7.2 --- Multiple adsorption and desorption cycle of metal ions --- p.54 / Chapter 2.8 --- Treatment of electroplating effluent by chitin A --- p.54 / Chapter 2.8.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.54 / Chapter 2.8.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.55 / Chapter 2.9 --- Data analysis --- p.56 / Chapter 3. --- Results --- p.58 / Chapter 3.1 --- Characterization of biosorbents --- p.58 / Chapter 3.1.1 --- Chitin assay --- p.58 / Chapter 3.1.2 --- Protein assay --- p.58 / Chapter 3.1.3 --- Metal analysis --- p.58 / Chapter 3.1.4 --- Degree of N-deacetylation analysis --- p.62 / Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.62 / Chapter B. --- Elemental analysis --- p.62 / Chapter 3.2 --- Selection of biosorbent for metal ion removal --- p.67 / Chapter 3.2.1 --- Effects of pretreatments of biosorbents on adsorption of Cu2+ --- p.67 / Chapter A. --- Washing --- p.67 / Chapter B. --- Pre-swelling --- p.67 / Chapter 3.2.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.67 / Chapter 3.2.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.70 / Chapter 3.3 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.70 / Chapter 3.3.1 --- Solution pH and concentration of biosorbent --- p.70 / Chapter 3.3.2 --- Retention time --- p.78 / Chapter 3.3.3 --- Initial metal ion concentration --- p.80 / Chapter 3.3.4 --- Presence of other cations --- p.93 / Chapter 3.3.5 --- Presence of anions --- p.93 / Chapter 3.4 --- "Optimization of Cu2+, Ni2+ and Zn2+ removal efficiencies" --- p.104 / Chapter 3.5 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden chitin A" --- p.104 / Chapter 3.5.1 --- Performances of various eluents on metal ion recovery --- p.104 / Chapter 3.5.2 --- Multiple adsorption and desorption cycle of metal ions --- p.109 / Chapter 3.6 --- Treatment of electroplating effluent by chitin A --- p.117 / Chapter 3.6.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.117 / Chapter 3.6.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.121 / Chapter 4. --- Discussion --- p.128 / Chapter 4.1 --- Characterization of biosorbents --- p.128 / Chapter 4.1.1 --- Chitin assay --- p.128 / Chapter 4.1.2 --- Protein assay --- p.129 / Chapter 4.1.3 --- Metal analysis --- p.129 / Chapter 4.1.4 --- Degree of N-deacetylation analysis --- p.130 / Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.130 / Chapter B. --- Elemental analysis --- p.132 / Chapter 4.2 --- Selection of biosorbent for metal ion removal --- p.133 / Chapter 4.2.1 --- Effects of pretreatments of biosorbents on adsorption of Cu2+ --- p.133 / Chapter A. --- Washing --- p.133 / Chapter B. --- Pre-swelling --- p.133 / Chapter 4.2.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.134 / Chapter 4.2.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.136 / Chapter 4.3 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.137 / Chapter 4.3.1 --- Solution pH and concentration of biosorbent --- p.137 / Chapter 4.3.2 --- Retention time --- p.138 / Chapter 4.3.3 --- Initial metal ion concentration --- p.139 / Chapter 4.3.4 --- Presence of other cations --- p.141 / Chapter 4.3.5 --- Presence of anions --- p.143 / Chapter 4.4 --- "Optimization of Cu2+, Ni2+ and Zn2+ removal efficiencies" --- p.147 / Chapter 4.5 --- "Recovery of Cu2+, Ni2+and Zn2+ from metal ion-laden chitin A" --- p.148 / Chapter 4.5.1 --- Performances of various eluents on metal ion recovery --- p.148 / Chapter 4.5.2 --- Multiple adsorption and desorption cycle of metal ions --- p.149 / Chapter 4.6 --- Treatment of electroplating effluent by chitin A --- p.150 / Chapter 4.6.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.150 / Chapter 4.6.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.152 / Chapter 5. --- Conclusion --- p.154 / Chapter 6. --- Further studies --- p.156 / Chapter 7. --- Summary --- p.158 / Chapter 8. --- References --- p.161

by Sze Kwok Fung Calvin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 118-130). / Acknowledgement --- p.i / Abstract --- p.ii / Content --- p.iv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Literature review --- p.1 / Chapter 1.1.1 --- Heavy metals in the environment --- p.1 / Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.2 / Chapter 1.1.3 --- Electroplating industry in Hong Kong --- p.6 / Chapter 1.1.4 --- Chemistry and toxicity of copper in the environment --- p.7 / Chapter 1.1.5 --- Methods of removal of heavy metal from industrial effluent --- p.9 / Chapter A. --- Physico-chemical methods --- p.9 / Chapter B. --- Biological methods --- p.9 / Chapter 1.1.6 --- Methods of recovery of heavy metal from metal-loaded biosorbent --- p.17 / Chapter 1.1.7 --- The physico-chemical properties of magnetites --- p.18 / Chapter 1.1.8 --- Magnetites for water and wastewater treatment --- p.19 / Chapter 1.1.9 --- Immobilized cell technology --- p.24 / Chapter 1.1.10 --- Stirrer-tank bioreactor --- p.26 / Chapter 1.2 --- Objectives of the present study --- p.28 / Chapter 2. --- Materials and Methods --- p.30 / Chapter 2.1 --- Selection of copper-resistant bacteria --- p.30 / Chapter 2.2 --- Culture media and chemicals --- p.30 / Chapter 2.3 --- Growth of the bacterial cells --- p.32 / Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.32 / Chapter 2.4.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.34 / Chapter 2.4.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.34 / Chapter 2.5 --- Copper ion uptake experiments --- p.35 / Chapter 2.6 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.35 / Chapter 2.7 --- Transmission electron micrograph and scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.36 / Chapter 2.7.1 --- Transmission electron micrograph --- p.36 / Chapter 2.7.2 --- Scanning electron micrograph --- p.37 / Chapter 2.8 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.37 / Chapter 2.9 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.38 / Chapter 2.9.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.38 / Chapter 2.9.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.39 / Chapter 2.10 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.39 / Chapter 2.10.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.39 / Chapter 2.10.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.40 / Chapter 2.11 --- Statistical analysis of data --- p.43 / Chapter 3. --- Results --- p.44 / Chapter 3.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.44 / Chapter 3.1.1 --- Effects of cells to magnetites ratio --- p.44 / Chapter 3.1.2 --- Effects of pH --- p.44 / Chapter 3.1.3 --- Effects of temperature --- p.44 / Chapter 3.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.49 / Chapter 3.3 --- Copper ion uptake experiments --- p.49 / Chapter 3.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.49 / Chapter 3.4.1 --- Effects of pH --- p.49 / Chapter 3.4.2 --- Effects of temperature --- p.53 / Chapter 3.4.3 --- Effects of retention time --- p.53 / Chapter 3.4.4 --- Effects of cations --- p.53 / Chapter 3.4.5 --- Effects of anions --- p.57 / Chapter 3.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62 / Chapter 3.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62 / Chapter 3.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68 / Chapter 3.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68 / Chapter 3.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.68 / Chapter 3.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.74 / Chapter 3.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.74 / Chapter 3.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.74 / Chapter 3.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.81 / Chapter 4. --- Discussion --- p.89 / Chapter 4.1 --- Selection of copper-resistant bacteria --- p.89 / Chapter 4.2 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.89 / Chapter 4.2.1 --- Effects of cells to magnetites ratio --- p.89 / Chapter 4.2.2 --- Effects of pH --- p.90 / Chapter 4.2.3 --- Effects of temperature --- p.91 / Chapter 4.2.4 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.92 / Chapter 4.3 --- Copper ion uptake experiments --- p.93 / Chapter 4.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.94 / Chapter 4.4.1 --- Effects of pH --- p.95 / Chapter 4.4.2 --- Effects of temperature --- p.96 / Chapter 4.4.3 --- Effects of retention time --- p.97 / Chapter 4.4.4 --- Effects of cations --- p.98 / Chapter 4.4.5 --- Effects of anions --- p.101 / Chapter 4.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.101 / Chapter 4.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.102 / Chapter 4.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.103 / Chapter 4.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.104 / Chapter 4.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.104 / Chapter 4.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.105 / Chapter 4.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.107 / Chapter 4.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.107 / Chapter 4.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.108 / Chapter 5. --- Conclusion --- p.110 / Chapter 6. --- Summary --- p.112 / Chapter 7. --- References --- p.115

by Lau Tsz Chun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 134-143). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Contents --- p.vi / List of Figures --- p.xi / List of Tables --- p.xv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Reviews --- p.1 / Chapter 1.1.1 --- Heavy metals in the environment --- p.1 / Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.3 / Chapter 1.1.3 --- Electroplating industries in Hong Kong --- p.7 / Chapter 1.1.4 --- "Chemistry, biochemistry and toxicity of selected metal ions: copper, nickel and zinc" --- p.8 / Chapter a. --- Copper --- p.10 / Chapter b. --- Nickel --- p.11 / Chapter c. --- Zinc --- p.12 / Chapter 1.1.5 --- Conventional physico-chemical methods of metal ions removal from industrial effluent --- p.13 / Chapter a. --- Ion exchange --- p.14 / Chapter b. --- Precipitation --- p.14 / Chapter 1.1.6 --- Alternative for metal ions removal from industrial effluent: biosorption --- p.15 / Chapter a. --- Definition of biosorption --- p.15 / Chapter b. --- Mechanisms involved in biosorption of metal ions --- p.17 / Chapter c. --- Criteria for a good metal sorption process and advantages of biosorption for removal of heavy metal ions --- p.19 / Chapter d. --- Selection of potential biosorbent for metal ions removal --- p.20 / Chapter 1.1.7 --- Procedures of biosorption --- p.23 / Chapter a. --- Basic study --- p.23 / Chapter b. --- Pilot-scale study --- p.25 / Chapter c. --- Examples of commercial biosorbent --- p.27 / Chapter 1.1.8 --- Seaweed as a potential biosorbent for heavy metal ions --- p.27 / Chapter 1.2 --- Objectives of study --- p.30 / Chapter 2. --- Materials and Methods --- p.33 / Chapter 2.1 --- Collection of seaweed samples --- p.33 / Chapter 2.2 --- Processing of seaweed biomass --- p.33 / Chapter 2.3 --- Chemicals --- p.33 / Chapter 2.4 --- Characterization of seaweed biomass --- p.39 / Chapter 2.4.1 --- Moisture content of seaweed biomass --- p.39 / Chapter 2.4.2 --- Metal ions content of seaweed biomass --- p.39 / Chapter 2.5 --- Characterization of metal ions biosorption by seaweed --- p.39 / Chapter 2.5.1 --- Effect of biomass weight and selection of biomass --- p.39 / Chapter 2.5.2 --- Effect of pH --- p.40 / Chapter 2.5.3 --- Effect of retention time --- p.41 / Chapter 2.5.4 --- Effect of metal ions concentration --- p.41 / Chapter 2.5.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.43 / Chapter 2.5.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening for suitable desorbing agents --- p.44 / Chapter 2.5.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.45 / Chapter 2.5.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.45 / Chapter 2.6 --- Statistical analysis of data --- p.46 / Chapter 3. --- Results --- p.47 / Chapter 3.1 --- Effect of biomass weight and selection of biomass --- p.47 / Chapter 3.1.1 --- Effect of biomass weight --- p.47 / Chapter 3.1.2 --- Selection of biomass --- p.58 / Chapter 3.2 --- Effect of pH --- p.58 / Chapter 3.2.1 --- Cu2+ --- p.58 / Chapter 3.2.2 --- Ni2+ --- p.61 / Chapter 3.2.3 --- Zn2+ --- p.61 / Chapter 3.2.4 --- Determination of optimal condition for biosorption of Cu2+ ，Ni2+ and Zn2+ by Ulva lactuca --- p.67 / Chapter 3.3 --- Effect of retention time --- p.67 / Chapter 3.4 --- Effect of metal ions concentration --- p.73 / Chapter 3.4.1 --- Relationship of removal capacity with initial concentration of metal ions --- p.73 / Chapter 3.4.2 --- Langmuir adsorption isotherm --- p.73 / Chapter 3.4.3 --- Freundlich adsorption isotherm --- p.77 / Chapter 3.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.81 / Chapter 3.5.1 --- Effect of mix-cations --- p.81 / Chapter 3.5.2 --- Effect of mix-anions --- p.85 / Chapter 3.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening of suitable desorbing agents --- p.91 / Chapter 3.6.1 --- Cu2+ --- p.91 / Chapter 3.6.2 --- Ni2+ --- p.91 / Chapter 3.6.3 --- Zn2+ --- p.91 / Chapter 3.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.94 / Chapter 3.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.97 / Chapter 4. --- Discussion --- p.106 / Chapter 4.1 --- Effect of biomass weight and selection of biomass --- p.106 / Chapter 4.1.1 --- Effect of biomass weight --- p.106 / Chapter 4.1.2 --- Selection of biomass --- p.107 / Chapter 4.2 --- Effect of pH --- p.109 / Chapter 4.3 --- Effect of retention time --- p.112 / Chapter 4.4 --- Effect of metal ions concentration --- p.114 / Chapter 4.4.1 --- Relationship of removal capacity with initial concentration of metal ions --- p.114 / Chapter 4.4.2 --- Langmuir adsorption isotherm --- p.114 / Chapter 4.4.3 --- Freundlich adsorption isotherm --- p.115 / Chapter 4.4.4 --- Insights from isotherm study --- p.117 / Chapter 4.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.118 / Chapter 4.5.1 --- Effect of mix-cations --- p.118 / Chapter 4.5.2 --- Effect of mix-anions --- p.120 / Chapter 4.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening of suitable desorbing agents --- p.122 / Chapter 4.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.124 / Chapter 4.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.126 / Chapter 5. --- Conclusion --- p.131 / Chapter 6. --- Summary --- p.134 / Chapter 7. --- References --- p.134 / Chapter 8. --- Appendixes --- p.144

Submitted in partial fulfillment of the requirements for the degree in Masters of Technology: Chemistry, ML Sultan Technikon, Durban, 2003. / The pollution of water bodies by heavy metals is a serious threat to humanity. The technique known as phytoremediation is used to clean up these polluted water bodies. The accumulation of heavy metals by aquatic plants is a safer, . cheaper and friendlier manner of cleaning the environment. The aquatic plants -studied in this project are A.sessilis, P.stratiotes, R.steudelii and T.capensis. The accumulation of heavy metals in aquatic plants growing in waste water treatment ponds was investigated. The water, sludge and plants were collected from five maturation ponds at the Northern Waste Water Treatment Works, Sea Cow Lake, Durban. The samples were analysed for Zn, Mn, Cr, Ni, Pb and Cu using ICP-MS. In general it was found that the concentrations of the targeted metals were much lower in the water (0.002 to 0.109 mg/I) compared to sediment/sludge (44 to 1543mg/kg dry wt) and plants (0.4 to 2246 mg/kg dry wt). These results show that water released into the river from the final maturation pond has metal concentrations well below the maximum limits set by international environmental control bodies. It also shows that sediments act as good sinks for metals and that plants do uptake metals to a significant extent. Of the four plants investigated it was found that }t.sessi[ir (leaves, roots and stems) and }A.sessilis (roots and stems) are relatively good collectors of Mn and Cu respectively. These findings are described in the thesis. The concentration of heavy metals in the stems, leaves and roots of the three plants were compared to ascertain if there were differences in the ability of the plant at different parts of the plant to bioaccumulate the six heavy metals studied. / M

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / The aim of this research was to reduce heavy metal and sulfate content of acid mine drainage (AMD) through the methods of passive filtration by combining permeable concrete and organic materials. This was to achieve a low cost, yet effective temporary treatment method for rural/poor communities who are affected by AMD. The acids are filtered through layers of alternating pervious concrete and biological composting layers. The concrete layers target removal of heavy metals such as iron, manganese, potassium, and magnesium, etc. through precipitation as well as reduce sulfate content to a small degree along with total dissolved solids. The concrete layers also aid in raising the pH of the AMD to more acceptable levels. The biological layers achieve sulfate remediation through the metabolism of sulfatereducing- bacteria (SRB). This process however required time and the organic layers were thus thicker and less permeable than the concrete layers in order to allow seepage to take place at a reduced rate. A wide variation of composting layers were tested, including cow manure, chicken manure, sawdust, straw, zoo manure, and leaf compost to find an optimum mix of materials which allows for the greatest sulfate reduction through sulfate reducing bacteria in the shortest possible time. Short as well as Long-term testing of rigs was undertaken to establish effectiveness, limitations and lifespan of the filtration systems. AMD from a mine in the Mpumalanga coal fields with exceptionally high sulfate content was used to test effectiveness of the organic materials over a short period of time. With long term testing conducted with a synthetic AMD, due to limited supply from the mine. The short term testing yielded removal of sulfates in the order of 56% when using kraal manure as the biological reagent mixed with sawdust for added organic carbon. The mix percentages by volume were 80%Sawdust to 20%manure and this setup was able to achieve the 56% removal of sulfates within 14 days. The filter also successfully raised the pH to 8 while removing a significant portion of heavy metals. The long term tests showed complete (100%) remediation of sulfates after a period of approximately sixty days. The tests are continuing to determine their finite lifespan and limitations. The results show promise for using the technology as a low cost, temporary measure to protect locally impacted groundwater, especially for isolated and/or rural communities while a permanent long term solution is sought.

A research project submitted to the Faculty of Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Sciences (Coursework and Research Report). Johannesburg, 2016. / Paenibacillus castaneae isolated from acid mine decant (Gauteng, South Africa) was previously shown to tolerate high concentrations of lead (Pb). The ability of the bacterium to tolerate/resist other heavy metals is probable and suggests a role for P. castaneae as a biosorbent for their removal from contaminated wastewaters. The current study aimed at determining whether the bacterium is also resistant to other common metal contaminants specifically, zinc (Zn) and nickel (Ni), found in South African wastewaters for biosorption by P. castaneae. Additionally, the influence of the external factors pH and competing cations on the uptake of these metals by the bacterium was evaluated. Specific rates of metal uptake (Q) were calculated indirectly from quantifying (by spectroscopy) the residual ion concentrations post exposure to 3 mM metal after various treatments. P. castaneae was found to tolerate Zn but showed vulnerability towards Ni. In a binary metal system, the bacterium showed a preferential metal uptake in the order Zn>>Co> Mn with a highest Q of 26 mg Zn/g biosorbent biomass recorded in the presence of Mn at pH 7. On the contrary, in a multimetal complex solution, the order of preference shifted to Co>>Zn with no absorption of Mn at the same pH. The results indicate that both pH and the presence of cations have an effect on the uptake of Zn by P. castaneae that could favour or inhibit its biosorption. The present study confirms the ability of P. castaneae to remove additional metals such as Zn, Mn and Co. These findings further suggest the potential of P. castaneae as a biosorbent for greener clean-up strategies of contaminated water facilities around Gauteng in the way of bioremediation. Keywords: P. castaneae, biosorption, specific metal uptake, zinc, lead, nickel / LG2017

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2016 / The remediation of acid mine drainage (AMD) has received much attention over the years due to the environmental challenges associated with its toxic constituents. Although, the current methods are able to remediate AMD, they also result in the loss of valuable products which could be recovered and the financial benefits used to offset the treatment costs. Therefore, this research focused on the removal of toxic heavy metals as well as the recovery of acid using a low cost adsorbent and acid retardation process, respectively. In the first aspect of the study, three low cost adsorbents namely zeolite, bentonite clay and cassava peel biomass were evaluated for metal uptake. The adsorption efficiencies of zeolite and bentonite, was found to be less than 50% for most metal ions, which was lower compared to the 90% efficiency obtained with cassava peel biomass. Subsequently, cassava peel biomass was chosen for further tests. The metal removal efficiency using the cassava biomass was in the order Co2+> Ni2+> Ca2+> Mn2+> Fe3+> Mg2+. The highest metal removal was attained at 2% adsorbent loading and 30 ˚C solution temperature. Amongst the equilibrium models tested, the experimental data was found to fit well with the Langmuir isotherm model. Column studies using the immobilized cassava waste biomass suggested that the breakthrough curves of most metal ions did not resemble the ideal breakthrough curve, due to the competitive nature of the ions present in the AMD used in this study. However, the experimental data from the column tests was found to correlate well with the Adam-Bohart model. Sulphuric acid recovery from the metal barren solution was evaluated using Dowex MSA-1 ion exchange resins. The results showed that sulphuric acid can be recovered by the resins via the acid retardation process, and could subsequently be upgraded to near market values of up to 70% sulphuric acid using an evaporator. Water of re-usable quality could also be obtained in the acid upgrade process. An economic evaluation of the proposed process also showed that it is possible to obtain revenue from sulphuric acid which could be used to offset some of the operational costs. / M T 2016

by So Chi Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / Acknowledgement --- p.i / Abstract --- p.ii / Chapter 1. --- Objectives of the Study --- p.1 / Chapter 2. --- Literature Review --- p.2 / Chapter 2.1 --- Heavy Metals in the Environment --- p.2 / Chapter 2.2 --- Heavy Metal Pollution in Hong Kong --- p.3 / Chapter 2.3 --- Chemistry and Toxicity of Copper in the Environment --- p.6 / Chapter 2.4 --- Conventional and Alternative Methods for Heavy Metal Removal --- p.10 / Chapter 2.5 --- Heavy Metal Removal by Microorganisms --- p.14 / Chapter 2.6 --- Factors Affecting Biosorption of Heavy Metals --- p.27 / Chapter 2.7 --- Applicability of Biosorbent in Heavy Metal Removal --- p.31 / Chapter 3. --- Materials and Methods --- p.36 / Chapter 3.1 --- Screening of Bacteria for Copper Removal Capacity --- p.36 / Chapter 3.1.1 --- Isolation of Bacteria from Activated Sludge --- p.36 / Chapter 3.1.2 --- Selection of Copper Resistant Bacteria from Water Samples --- p.37 / Chapter 3.1.3 --- Pre-screening of Bacteria for Copper Uptake --- p.37 / Chapter 3.1.4 --- Determination of Copper Removal Capacity of Selected Bacteria --- p.37 / Chapter 3.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.39 / Chapter 3.2.1 --- Effect of Nutrient Limitation --- p.39 / Chapter 3.2.2 --- Effect of Incubation Temperature and Culture Age --- p.41 / Chapter 3.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.41 / Chapter 3.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.41 / Chapter 3.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.43 / Chapter 3.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.43 / Chapter 3.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.43 / Chapter 3.5.1 --- Determination of Copper Uptake Kinetics --- p.43 / Chapter 3.5.2 --- Determination of Freundlich Isotherm for Copper Uptake --- p.44 / Chapter 3.5.3 --- Effect of pH on Copper Removal Capacity --- p.44 / Chapter 3.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.44 / Chapter 3.5.5 --- Effect of Anions on Copper Removal Capacity --- p.45 / Chapter 3.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.45 / Chapter 3.6.1 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.47 / Chapter 3.6.2 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.47 / Chapter 3.6.3 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles --- p.48 / Chapter 3.6.4 --- Treatments of Effluent from an Electroplating Factory by Immobilized Cells --- p.48 / Chapter 4. --- Results --- p.49 / Chapter 4.1 --- Screening of Bacteria for Copper Removal Capacity --- p.49 / Chapter 4.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.49 / Chapter 4.2.1 --- Effect of Nutrient Limitation --- p.49 / Chapter 4.2.2 --- Effect of Incubation Temperature and Culture Age --- p.52 / Chapter 4.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.52 / Chapter 4.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.52 / Chapter 4.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.52 / Chapter 4.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.56 / Chapter 4.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.56 / Chapter 4.5.1. --- Determination of Copper Uptake Kinetics --- p.56 / Chapter 4.5.2 --- Determination of Freundlich Isotherm for Copper Uptake --- p.56 / Chapter 4.5.3 --- Effect of pH on Copper Removal Capacity --- p.60 / Chapter 4.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.60 / Chapter 4.5.5 --- Effect of Anions on Copper Removal Capacity --- p.60 / Chapter 4.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.60 / Chapter 4.6.1 --- Copper Removal Capacity of Immobilized Cells and Breakthrough Curve for Copper Removal --- p.60 / Chapter 4.6.2 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.65 / Chapter 4.6.3 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.65 / Chapter 4.6.4 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles --- p.65 / Chapter 4.6.5 --- Treatment of Effluent from an Electroplating Factory by Immobilized Cells --- p.65 / Chapter 5. --- Discussion --- p.72 / Chapter 5.1 --- Screening of Bacteria for Copper Removal Capacity --- p.72 / Chapter 5.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.73 / Chapter 5.2.1 --- Effect of Nutrient Limitation --- p.73 / Chapter 5.2.2 --- Effect of Incubation Temperature and Culture Age --- p.74 / Chapter 5.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.75 / Chapter 5.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.75 / Chapter 5.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.75 / Chapter 5.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.76 / Chapter 5.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.77 / Chapter 5.5.1 --- Copper Uptake Kinetics --- p.77 / Chapter 5.5.2 --- Freundlich Isotherm for Copper Uptake --- p.78 / Chapter 5.5.3 --- Effect of pH on Copper Removal Capacity --- p.78 / Chapter 5.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.79 / Chapter 5.5.5 --- Effect of Anions on Copper Removal Capacity --- p.80 / Chapter 5.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.80 / Chapter 5.6.1 --- Copper Removal Capacity of Immobilized Cells and Breakthrough Curve for Copper Removal --- p.80 / Chapter 5.6.2 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.82 / Chapter 5.6.3 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.82 / Chapter 5.6.4 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles 的 --- p.83 / Chapter 5.6.5 --- Treatment of Effluent from an Electroplating Factory by Immobilized Cells --- p.84 / Chapter 6. --- Conclusion --- p.85 / Chapter 7. --- Summary --- p.87 / Chapter 8. --- References --- p.89

Penicillium ochro-chloron (ATCC strain # 36741), a filamentous fungus with the capability for removing copper ions from aqueous solutions, was studied as a possible biological trap (biotrap) for remediation of heavy metal contaminants in industrial wastewaters. This research demonstrated that in shake flasks the fungus removed copper from surrogate wastewater with 100mg/L copper contamination by as much as 99%. These results did not translate to the bioreactor configuration of a packed bed column, as channeling occurred through the bed, shown by conductivity tracer studies. A fluidized bed configuration was studied and resulted in copper removal of 97%, with a capacity of 149 mg[Cu]/g dry weight biomass, under the conditions of 50% dissolved oxygen. For dissolved oxygen concentrations below the critical oxygen concentration for the fungus (20% saturation) there was minimal copper removal. Mixing studies in the fluidized bed reactor showed that the system was diffusion limited. Mathematical modeling using first order kinetics associated with diffusion limited reactions resulted in rate constants for Cu 2+ uptake of approximately 0.031 h -1 , which were dependent on the dissolved oxygen concentration. Modeling of the reaction with a second order kinetic equation showed that there are possibly factors regulating copper uptake besides oxygen. Electron microscopy showed that in some instances the copper removed was retained as large porous spherical extracellular precipitates. Energy Dispersive X-ray (EDX) analysis has shown similar complexes to be copper phosphate precipitates (Crusberg, 1994). Removal of heavy metal contaminants from wastewater discharge is a necessity for many industries, due to environmental concerns and federal regulations. The use of a biological system for the removal and recycling of heavy metals could prove more economical than currently used physio-chemical processes.