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

by Chan Hiu-wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 123-133). / Text in English; abstracts in English and Chinese. / by Chan Hiu-wai. / Acknowledgements --- p.i / Abstract --- p.ii / List of Figures --- p.x / List of Tables --- p.xiii / List of Abbreviations --- p.xv / Page / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The chemical class: Phthalate esters --- p.1 / Chapter 1.2 --- Di(2-ethylhexyl)phthalate --- p.2 / Chapter 1.2.1 --- Characteristics of DEHP --- p.5 / Chapter 1.2.2 --- Production and applications --- p.5 / Chapter 1.2.3 --- Environmental releases and environmental fate --- p.8 / Chapter 1.2.4 --- Toxicity of DEHP --- p.8 / Chapter 1.2.4.1 --- Mammalian toxicity --- p.9 / Chapter 1.2.4.2 --- Toxicity to aquatic organisms --- p.10 / Chapter 1.2.5 --- Regulations --- p.10 / Chapter 1.3 --- Conventional technologies for DEHP removal --- p.11 / Chapter 1.3.1 --- Biodegradation --- p.11 / Chapter 1.3.2 --- Coagulation --- p.11 / Chapter 1.3.3 --- Adsorption --- p.11 / Chapter 1.4 --- Innovative technologies for DEHP removal --- p.12 / Chapter 1.4.1 --- Biosorption --- p.13 / Chapter 1.4.1.1 --- Definition of biosorption --- p.13 / Chapter 1.4.1.2 --- Mechanisms --- p.13 / Chapter 1.4.1.3 --- Selection of biosorbents --- p.17 / Chapter 1.4.1.4 --- Assessment of biosorption performance --- p.21 / Chapter a. --- Batch adsorption experiments --- p.21 / Chapter b. --- Modeling of biosorption --- p.21 / Chapter 1.4.1.5 --- Recovery of biosorbents --- p.23 / Chapter 1.4.1.6 --- Development of biosorption process --- p.23 / Chapter 1.4.1.7 --- Seaweeds as biosorbents --- p.24 / Chapter 1.4.2 --- Advanced oxidation processes --- p.27 / Chapter 1.4.3 --- Heterogeneous photocatalytic oxidation --- p.30 / Chapter 1.4.3.1 --- Photocatalyst --- p.30 / Chapter 1.4.3.2 --- General mechanisms --- p.31 / Chapter 1.4.3.3 --- Influencing parameters in PCO --- p.33 / Chapter 1.4.3.4 --- Enhanced performance by addition of hydrogen peroxide --- p.33 / Chapter 2 --- Objectives --- p.36 / Chapter 3 --- Materials and Methods --- p.38 / Chapter 3.1 --- Chemical reagents --- p.38 / Chapter 3.2 --- Biosorption of DEHP by seaweed biomass --- p.39 / Chapter 3.2.1 --- Biosorbents --- p.39 / Chapter 3.2.2 --- Determination method of DEHP --- p.39 / Chapter 3.2.3 --- Batch adsorption experiments --- p.44 / Chapter 3.2.3.1 --- Screening of potential biomass --- p.44 / Chapter 3.2.3.2 --- Characterization of beached seaweed and S. siliquastrum --- p.44 / Chapter a. --- Total organic carbon (TOC) content --- p.44 / Chapter b. --- Leaching of biomass components --- p.45 / Chapter 3.2.3.3 --- Combined effect of pH and biomass concentration --- p.45 / Chapter 3.2.3.4 --- Effect of retention time --- p.45 / Chapter 3.2.3.5 --- Effect of agitation rate --- p.45 / Chapter 3.2.3.6 --- Effect of temperature --- p.46 / Chapter 3.2.3.7 --- Effect of particle size --- p.46 / Chapter 3.2.3.8 --- Effect of DEHP concentration --- p.46 / Chapter 3.2.4 --- Recovery of adsorbed DEHP from seaweed biomass --- p.47 / Chapter 3.2.4.1 --- Screening for suitable desorbing agents --- p.47 / Chapter 3.2.4.2 --- Multiple adsorption-desorption cycles --- p.47 / Chapter 3.2.5 --- Statistical analysis --- p.43 / Chapter 3.3 --- Photocatalytic oxidation --- p.48 / Chapter 3.3.1 --- Photocatalytic reactor --- p.48 / Chapter 3.3.2 --- Optimization of reaction conditions --- p.48 / Chapter 3.3.2.1 --- Effect of reaction time --- p.48 / Chapter 3.3.2.2 --- Effect of initial pH --- p.51 / Chapter 3.3.2.3 --- Effect of Ti02 concentration --- p.51 / Chapter 3.3.2.4 --- Effect of UV intensity --- p.52 / Chapter 3.3.2.5 --- Effect of H202 concentration --- p.52 / Chapter 3.3.2.6 --- Effect of initial DEHP concentration and irradiation time --- p.52 / Chapter 3.3.2.7 --- Statistical analysis --- p.52 / Chapter 3.3.4 --- Determination of mineralization of DEHP by analyzing total Organic carbon (TOC) content --- p.53 / Chapter 3.3.5 --- Identification of intermediate products of DEHP --- p.53 / Chapter 3.3.6 --- Evaluation for the toxicity of DEHP and intermediate products --- p.53 / Chapter 3.3.6.1 --- Microtox® test --- p.53 / Chapter 3.3.6.2 --- Amphipod survival test --- p.55 / Chapter 3.4 --- Feasibility of combining biosorption and photocatalyic oxidation as an Integrated treatment for DEHP --- p.57 / Chapter 3.4.1 --- Effect of algal extract on photocatalytic oxidation of DEHP --- p.57 / Chapter 3.4.2 --- Determination of mineralization of algal extract by analyzing total organic carbon (TOC) --- p.57 / Chapter 4 --- Results --- p.58 / Chapter 4.1 --- Determination method of DEHP --- p.58 / Chapter 4.2 --- Biosorption --- p.58 / Chapter 4.2.1 --- Batch adsorption experiments --- p.58 / Chapter 4.2.1.1 --- Screening of potential biomass --- p.58 / Chapter 4.2.1.2 --- Characterization of beached seaweed and S. siliquastrum --- p.61 / Chapter a. --- Total organic carbon (TOC) content --- p.61 / Chapter b. --- Leaching properties --- p.61 / Chapter 4.2.1.3 --- Combined effect of pH and biomass concentration --- p.61 / Chapter 4.2.1.4 --- Effect of retention time --- p.74 / Chapter 4.2.1.5 --- Effect of agitation rate --- p.74 / Chapter 4.2.1.6 --- Effect of temperature --- p.74 / Chapter 4.2.1.7 --- Effect of particle size --- p.74 / Chapter 4.2.1.8 --- Effect of initial DEHP concentration: Modeling by Langmuir and Freundlich adsorptin isotherm --- p.79 / Chapter 4.2.2 --- Recovery of adsorbed DEHP by seaweed biomass --- p.84 / Chapter 4.2.2.1 --- Screening for suitable desorbing agents --- p.84 / Chapter 4.2.2.2 --- Multiple adsorption-desorption cycles --- p.84 / Chapter 4.3 --- Photocatalytic oxidation --- p.90 / Chapter 4.3.1 --- Optimization of reaction conditions --- p.90 / Chapter 4.3.1.1 --- Effect of reaction time --- p.90 / Chapter 4.3.1.2 --- Effect of initial pH --- p.90 / Chapter 4.3.1.3 --- Effect of TiO2 concentration --- p.90 / Chapter 4.3.1.4 --- Effect of UV intensity --- p.90 / Chapter 4.3.1.5 --- Effect of H2O2 concentration --- p.95 / Chapter 4.3.1.6 --- Effect of initial DEHP and irradiation time --- p.95 / Chapter 4.3.2 --- Determination of mineralization of DEHP by analyzing total organic carbon (TOC) --- p.95 / Chapter 4.3.3 --- Identification of intermediate products of DEHP --- p.95 / Chapter 4.3.4 --- Evaluation for the toxicity of DEHP and the intermediate products --- p.102 / Chapter 4.3.4.1 --- Microtox® test --- p.102 / Chapter 4.3.4.2 --- Amphipod survival test --- p.102 / Chapter 4.4 --- Feasibility of combining biosorption and photocatalytic oxidation as an integrated treatment for DEHP --- p.102 / Chapter 4.4.1 --- Effect of algal extract on photocatalytic oxidation of DEHP --- p.102 / Chapter 4.4.2 --- Determination of mineralization of algal extract by analyzing total organic carbon (TOC) --- p.103 / Chapter 5 --- Discussion --- p.108 / Chapter 5.1 --- Determination method of DEHP --- p.108 / Chapter 5.2 --- Biosorption --- p.108 / Chapter 5.2.1 --- Batch adsorption experiments --- p.108 / Chapter 5.2.1.1 --- Screening of potential biomass --- p.108 / Chapter 5.2.1.2 --- Characteristic of S. siliquastrum and beached seaweed --- p.109 / Chapter 5.2.1.3 --- Combined effect of pH and biomass concentration --- p.109 / Chapter 5.2.1.4 --- Effect of retention time --- p.111 / Chapter 5.2.1.5 --- Effect of agitation rate --- p.111 / Chapter 5.2.1.6 --- Effect of temperature --- p.111 / Chapter 5.2.1.7 --- Effect of particle size --- p.112 / Chapter 5.2.1.8 --- Effect of initial DEHP concentration: Modeling of Langmuir and Freundlich adsorption isotherms --- p.112 / Chapter 5.2.2 --- Recovery of adsorbed DEHP by seaweed biomass --- p.114 / Chapter 5.2.2.1 --- Screening for suitable desorbing agents --- p.114 / Chapter 5.2.2.2 --- Multiple adsorption-desorption cycles --- p.115 / Chapter 5.3 --- Photocatalytic oxidation --- p.115 / Chapter 5.3.1 --- Optimization of reaction conditions --- p.115 / Chapter 5.3.1.1 --- Effect of reaction time --- p.115 / Chapter 5.3.1.2 --- Effect of pH --- p.116 / Chapter 5.3.1.3 --- Effect of TiO2 concentration --- p.116 / Chapter 5.3.1.4 --- Effect of UV intensity --- p.116 / Chapter 5.3.1.5 --- Effect of H2O2 concentration --- p.117 / Chapter 5.3.1.6 --- Effect of DEHP concentration and irradiation time --- p.117 / Chapter 5.3.2 --- Determination of mineralization of DEHP by analyzing total organic carbon (TOC) --- p.117 / Chapter 5.3.3 --- Identification of intermediate products of DEHP --- p.118 / Chapter 5.3.4 --- Evaluation for the toxicity of DEHP and the intermediate products --- p.119 / Chapter 5.4 --- Feasibility of combining biosorption and photocatalytic oxidation as an integrated treatment for DEHP --- p.119 / Chapter 6 --- Conclusions --- p.121 / Chapter 7 --- References --- p.123

M.Tech. Engineering: Chemical. / Aims at demonstrating the application of semi-continuous and continuous magnetic adsorption separation (MAS) techniques to extract Cr (VI) ions from wastewater streams using PPy-Fe3O4 nanocomposite. Specifically, the research aims to achieve the following objectives: to design, synthesize and characterize new generation PPy-Fe3O4 nanocomposite with varied magnetite composition for hexavalent chromium removal ; to generate batch adsorption kinetic data in a continuously stirred tank reactor (CSTR) and apply existing kinetic models to aid in water treatment system design.; to design and construct magnetic adsorption separation (MAS) device that can operate in a semi-continuous and continuous mode and explore their performances and to optimize the systems' performance.

Thesis (M. Tech.: Biotechnology)-Dept. of Biotechnology and Food Technology, Durban University of Technology, 2008. xiv, 103 leaves : ill. / Phytoremediation is an emerging technology where specially selected and engineered metal-accumulating plants are used for bioremediation. Amaranthus dubius (marog or wild spinach) is a popular nutritious leafy vegetable crop which is widespread especially in the continents of Africa, Asia and South America. Their rapid growth and great biomass makes them some of the highest yielding leafy crops which may be beneficial for phytoremediation. This study was undertaken to evaluate the potential of A. dubius for the phytoremediation of Chromium (Cr), Mercury (Hg), Arsenic (As), Lead (Pb), Copper (Cu) and Nickel (Ni). Locally gathered soil and plants of A. dubius were investigated for the metals from a regularly cultivated area, a landfill site and a sewage site. Metals were extracted from the samples using microwave-digestion and analyzed using Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS). Further experiments were conducted with plants from locally collected seeds of A. dubius, in a tunnel house under controlled conditions. The mode of phytoremediation, the effect of the metals on the plants, the ability of the plant to extract metals from soil (Bioconcentration Factor - BCF), and the ability of the plants to move the metals to the aerial parts of the plants (Translocation Factor - TF) were evaluated for the different metals. Finally, A. dubius was micro-propagated in a tissue culture system with and without exposure to the metal, and the effect was studied by electron microscopy.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Botany / Master / Master of Philosophy

published_or_final_version / Chemistry / Master / Master of Philosophy

published_or_final_version / abstract / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Civil Engineering / Master / Master of Philosophy

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy