by Fung King-yuen Debera. / On t.p., "2+" is superscript. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 102-112). / Acknowledgement --- p.i / Abstract --- p.ii / Table of Content --- p.iv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Literature review --- p.1 / Chapter 1.1.1 --- Problems of heavy metals in the environment --- p.1 / Chapter 1.1.2 --- Methods of removal of heavy metal from industrial effluent --- p.5 / Chapter 1.1.3 --- The properties of magnetites --- p.10 / Chapter 1.1.4 --- Role of magnetites in water treatment --- p.12 / Chapter 1.1.5 --- The advantages of using magnetites and further application of magnetites --- p.16 / Chapter 1.2 --- Objectives of the study --- p.21 / Chapter 2. --- Materials and methods --- p.23 / Chapter 2.1 --- Selection of the organisms --- p.23 / Chapter 2.2 --- Culture media and chemicals --- p.23 / Chapter 2.3 --- Growth of the bacterial cells --- p.25 / Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.27 / Chapter 2.4.1 --- Effects of chemical and physical factors on the immobilization of the bacterial cells on magnetites --- p.27 / Chapter 2.4.2 --- Effect of pH on the desorption of cells from magnetites --- p.28 / Chapter 2.5 --- Nickel ion uptake experiments --- p.28 / Chapter 2.6 --- Effects of operational conditions on the nickel removal capacity of the magnetite-immobilized bacterial cells --- p.29 / Chapter 2 .6.1 --- Effect of physical factors --- p.29 / Chapter 2.6.2 --- Effect of chemical factors --- p.30 / Chapter 2.7 --- Optimization of the nickel removal efficiency --- p.30 / Chapter 2.8 --- Nickel adsorption isotherm of the magnetite- immobilized cells of Enterobacter sp4-2 --- p.30 / Chapter 2.9 --- Recovery of adsorbed Ni2+ from the magnetite- immobilized cells of Enterobacter sp4-2 --- p.31 / Chapter 2.9.1 --- Multiple adsorption-desorption cycles of Ni2+ by using citrate buffer --- p.32 / Chapter 2.9.2 --- Multiple adsorption-desorption cycles of Ni2+ by using ethylenediaminetetraacetic acid (EDTA) --- p.33 / Chapter 2.10 --- Effect of acidic treatment --- p.33 / Chapter 2.10.1 --- Effect of acidic treatment on the nickel removal capacity of the magnetites and the magnetite- immobilized cells of Enterobacter sp4-2 --- p.33 / Chapter 2.10.2 --- Effect of acidic treatment on the recovery of the adsorbed Ni2+ from magnetites and the magnetite- immobilized cells Enterobacter sp4-2 --- p.34 / Chapter 2.11 --- Removal and recovery of Ni2+ from the electroplating effluent --- p.34 / Chapter 3. --- Results --- p.36 / Chapter 3.1 --- Effects of chemical and physical factors on the immobilization of the bacterial cells on magnetites --- p.36 / Chapter 3.1.1 --- Effect of pH --- p.36 / Chapter 3.1.2 --- Effect of cells to magnetites ratio --- p.36 / Chapter 3.1.3 --- Effect of temperature --- p.39 / Chapter 3.2 --- Effect of pH on the desorption of cells from magnetites --- p.39 / Chapter 3.3 --- Nickel ion uptake experiments --- p.44 / Chapter 3.4 --- Effects of operational conditions on the nickel removal capacity of the magnetite-immobilized bacterial cells --- p.44 / Chapter 3.4.1 --- Effect of reaction temperature --- p.44 / Chapter 3.4.2 --- Effect of retention time --- p.44 / Chapter 3.4.3 --- Effect of pH --- p.47 / Chapter 3.4.4 --- Effect of the presence of cations --- p.50 / Chapter 3.4.5 --- Effect of the presence of anions --- p.50 / Chapter 3.5 --- Optimization of the nickel removal efficiency --- p.55 / Chapter 3.6 --- Nickel adsorption isotherm of the magnetite- immobilized cells of Enterobacter sp4-2 --- p.55 / Chapter 3.7 --- Recovery of adsorbed Ni2+ from the magnetite- immobilized cells of Enterobacter sp4-2 --- p.59 / Chapter 3.7.1 --- Multiple adsorption-desorption cycles of Ni2+ by using citrate buffer --- p.59 / Chapter 3.7.2 --- Multiple adsorption-desorption cycles of Ni2+ by using ethylenediaminetetraacetic acid (EDTA) --- p.63 / Chapter 3.8 --- Effect of acidic treatment --- p.63 / Chapter 3.8.1 --- Effect of acidic treatment on the nickel removal capacity of the magnetites and the magnetite-immobilized cells of Enterobacter sp4-2 --- p.63 / Chapter 3.8.2 --- Effect of acidic treatment on the recovery of the adsorbed Ni2+ from the magnetites and the magnetite-immobilized cells of Enterobacter sp4-2 --- p.66 / Chapter 3.9 --- Removal and recovery of Ni2+ from the electroplating effluent --- p.69 / Chapter 4. --- Discussion --- p.72 / Chapter 4.1 --- Selection of the organisms --- p.72 / Chapter 4.2 --- Effects of chemical and physical factors on the immobilization of the bacterial cells on magnetites --- p.72 / Chapter 4.2.1 --- Effect of pH --- p.72 / Chapter 4.2.2 --- Effect of cells to magnetites ratio --- p.74 / Chapter 4.2.3 --- Effect of temperature --- p.75 / Chapter 4.2.4 --- Effect of pH on the desorption of cells from magnetites --- p.76 / Chapter 4.3 --- Nickel ion uptake experiments --- p.78 / Chapter 4.4 --- Effects of operational conditions on the nickel removal capacity of the magnetite-immobilized bacterial cells --- p.80 / Chapter 4.4.1 --- Effect of reaction temperature --- p.80 / Chapter 4.4.2 --- Effect of retention time --- p.81 / Chapter 4.4.3 --- Effect of pH --- p.82 / Chapter 4.4.4 --- Effect of the presence of cations --- p.83 / Chapter 4.4.5 --- Effect of the presence of anions --- p.84 / Chapter 4.5 --- Optimization of the nickel removal efficiency --- p.85 / Chapter 4.6 --- Nickel adsorption isotherm of the magnetite- immobilized cells of Enterobacter sp4-2 --- p.86 / Chapter 4.7 --- Recovery of adsorbed Ni2+ from the magnetite- immobilized cells of Enterobacter sp4-2 --- p.87 / Chapter 4.7.1 --- Multiple adsorption-desorption of Ni2+ --- p.89 / Chapter 4.7.2 --- Effect of acidic treatment on the nickel removal capacity and recovery --- p.91 / Chapter 4.8 --- Removal and recovery of Ni2+ from the electroplating effluent --- p.93 / Chapter 5. --- Conclusion --- p.96 / Chapter 6. --- Summary --- p.99 / Chapter 7. --- References --- p.102