Researchers at Rhodes University conducted investigations into the anaerobic co-disposal of primary sewage sludge (PSS) and high sulphate acid mine drainage (AMD) resulting in the development of the Rhodes BioSURE Process® which forms the basis for the operation of a pilot recycling sludge bed reactor (RSBR). Further research has been conducted by researchers at the University of Cape Town (UCT), with the principle aim of determining the rate of hydrolysis of PSS under rnethanogenic, acidogenic and sulphate reducing conditions in laboratory-scale anaerobic digesters. The University of Cape Town's Anaerobic Digestion Model No.1 (UCTADMI) which integrates various biological anaerobic processes for the production of methane was extended with the development of a mathematical model incorporating the processes of biosulphidogenic reduction and the biology of sulphate reducing bacteria (SRB). Kinetic parameters used in the model were obtained from SOtemann et al. (2005b) and Kalyuzhnyi et al. (1998). The WEST® software was used as a platform in translation of the basic UCTADMI from AQUASIM, and subsequently applied to data sets from UCT laboratory experiments. Incomplete closure of mass balances was attributed to incorrect reaction stoichiometry inherited through translation of the AQUASIM model into WEST®. The WEST® implementation of the model to the experimental methanogenic systems gave fairly close correlations between predicted and measured data for a single set of stoichiometric and kinetic constants, with regressed hydrolysis rate constants. Application of the extended UCTADMI to experimental sulphidogenic systems demonstrated simulation results reasonably close to measured data, with the exception of effluent soluble COD and sulphate concentrations. Except for a single system with a high COD:Sat ratio, sulphidogens are out competed for substrate by methanogens within the model. Therefore the model does not properly represent the competition between methanogenic and sulphidogenic organism groups. Trends observed in application of the model to available pilot plant RSBR data were similar to those observed in sulphidogenic systems, resulting in methanogens out-competing sulphidogens. The model was used as a tool to explore various scenarios regarding operation of the pilot plant. Based on the work conducted in this study, various areas for further information and research were highlighted and recommended. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.

Submitted in complete fulfillment for the degree of Doctor of Philosophy (Biotechnology) in the Department of Biotechnology and Food Technology, Durban University of Technology, Durban, South Africa, 2016. / Many households in developing countries are still without proper sanitation systems. The problems are even more prevalent in rural communities where there are no septic systems in place for the treatment of wastewater. This has resulted in the urgent need for the development and implementation of innovative wastewater treatment systems that are inexpensive, environmental friendly and are able to reduce contaminants to levels that pose no harm to the communities. Constructed rhizofiltration systems have been explored for this purpose. They have been used for many decades in many countries with varying degrees of success at the primary, secondary and tertiary levels of wastewater treatment. Poor optimization of this technology has been due to limited information available about the roles played by the whole system as well as by each component involved in the treatment technology. The current work elucidates the role played by macrophytes and microbial biofilms in the removal of nutrients in the rhizofiltration system. Factors affecting waste removal as well as environmental friendliness of the system were also investigated. The rhizofiltration system was constructed in Durban and was divided into planted (planted with Phragmites australis and Kyllinga nemoralis) and unplanted (reference) section. Dissolved oxygen (DO), pH, water temperature, total dissolved solids (TDS), electrical conductivity (EC) and salinity were monitored. The removal efficiency of nutrients was measured using spectrophotometric methods by measuring the concentration of ammonia, nitrate, nitrite, phosphate and orthophosphate in the wastewater pre- and post-treatment. The total organic carbon, chemical oxygen demand (COD), total Kehldjahl nitrogen, biological oxygen demand (BOD), ammonia, nitrate and the flow rate of wastewater into the system from the settling tank were used for the estimation of carbon dioxide, methane and nitrous oxide emitted from the rhizofilter using the 2009 EPA formulae. Both the planted and reference sections of the system removed nutrients with varying efficiencies. The reduction of nutrients in the rhizofilter was found to be seasonal, with most nutrients removed during the warm seasons. The system also retained more nutrients when wastewater containing low levels of nutrients was used. The unpaired t-test was used to determine the differences between nutrient removals between planted and reference sections. Higher reduction efficiencies of nutrients were obtained in the planted section. Up to 65% nitrite and 99% nitrate were removed while up to 86% total phosphorus was removed in a form of orthophosphate (86%). Removal of total nitrogen was shown to increase under high temperature conditions, while the same conditions decreased the total phosphorus removal. High temperatures also increased the performance of the system. The reduction of nutrients in the system corresponded to reduction of the chemical oxygen demand which also positively correlated to the dissolved oxygen concentration. Considering the discharge limits for all nutrients, the discharges in the effluent of the planted section were within the allowable limits as per South Africa’s Department of Water affairs and Forestry in 2012 but not in 2013. The results obtained in 2013 were due to increased nutrient loading introduced into the system. Diverse microbial communities occurred in the treatment system, with more diversity in the planted section. These organisms were supported by macrophytes in the planted section, and were responsible for nitrogen and phosphorus transformation. This explains why total nitrogen and phosphorus reduction was higher in the planted compared to the reference section. Both the planted and the reference sections of the rhizofiltration system produced the greenhouse gases. When the two sections were compared, the planted section produced more gases. Gases emitted by both sections were lower when compared to emission from sludge treatment reed beds and other conventional systems of wastewater treatments. These findings indicated that constructed rhizofiltration is a cleaner form of waste treatment, producing significantly less greenhouse gases and affecting less of a climate change. Findings of this work have revealed that rhizofiltration technology can be used as a low-cost alternative technology for the treatment of wastewater, using the combination of macrophytes and microbial biofilms. Macrophytes accumulated nitrogen and phosphorus as well as supported diverse microorganisms that metabolized and reduced nutrients in the rhizofiltration unit. / D

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

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2019. / The biodiesel industry produces large volumes of biodiesel wastewater (BDWW) during the purification of crude biodiesel. This wastewater is characterised by high concentrations of chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), and fats, oils and greases (FOG) which in turn defines BDWW as a highly polluted effluent. The low nitrogen and phosphorous content of BDWW creates an unfavourable environment for the growth of microorganisms, thereby making it difficult to degrade naturally. Biodiesel companies discharge untreated non-compliant wastewater directly to the municipal sewer system. Treatment prior to discharge is a necessity since the disposal of untreated BDWW may raise serious environmental concerns (i.e. disturbance of biological ecosystems) resulting in penalties liable by non-compliant companies due to the implementation of the waste discharge charge system (WDCS) which is regulated by the industrial waste discharge standard limits in South Africa (SA). This study aimed to combine the advantages of the conventional anaerobic baffled reactor (ABR) system with microbial fuel cell (MFC) technology resulting in an innovative technology used to treat high strength industrial BDWW at ambient conditions. Many studies have reported effective treatment of BDWW, however to date literature implementing an ABR equipped with MFC technology has not been reported. The main objectives of the study were to determine which parameters do not meet the industrial wastewater discharge standard limits, whether pH and carbon:nitrogen:phosphorous (C:N:P) ratio adjustments will suffice prior to treatment with the ABR-MFC, the maximum power density (PD) as well as to determine the treatment efficiency of the ABR-MFC.

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

by Chung Wai Ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 110-120). / Acknowledgments --- p.i / Abstract --- p.ii / Table of Content --- p.iii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Sewage Treatment --- p.1 / Chapter 1.1.1 --- Overview --- p.1 / Chapter 1.1.2 --- Types of Treatment --- p.2 / Chapter 1.2 --- Activated Sludge Process --- p.3 / Chapter 1.2.1 --- Overview --- p.3 / Chapter 1.2.2 --- Biology of Activated Sludge --- p.3 / Chapter 1.2.3 --- Operation of the Activated Sludge Process --- p.4 / Chapter 1.2.4 --- Floe Formation in Activated Sludge Process --- p.10 / Chapter 1.2.5 --- Operational Problems Associated with the Activated Sludge Process --- p.12 / Chapter 1.2.5.1 --- Bulking --- p.12 / Chapter 1.2.5.2 --- Foaming --- p.14 / Chapter 1.3 --- Foaming in Activated Sludge Process --- p.15 / Chapter 1.3.1 --- Overview --- p.15 / Chapter 1.3.2 --- Causes of Foaming --- p.16 / Chapter 1.3.2.1 --- Biology of Nocardia --- p.18 / Chapter 1.3.2.2 --- Growth Strategy of Nocardia --- p.18 / Chapter 1.3.2.3 --- Metabolic Specialization of Nocardia amarae --- p.19 / Chapter 1.3.3 --- Controls of Foaming --- p.20 / Chapter 1.4 --- Microbial Lipid and Bacterial Foaming --- p.23 / Chapter 1.4.1 --- Overview --- p.23 / Chapter 1.4.2 --- Fatty Acids in Bacteria --- p.24 / Chapter 1.4.3 --- Analytical Techniques --- p.25 / Chapter 1.4.3.1 --- Chromatography --- p.25 / Chapter 1.4.3.2 --- Gas Chromatography - Mass Spectrometry (GC-MS) --- p.26 / Chapter 1.4.4 --- Significance of Fatty Acids to Foaming --- p.27 / Chapter 1.5 --- Disinfection --- p.29 / Chapter 1.5.1 --- Overview --- p.29 / Chapter 1.5.2 --- Types of Disinfectants --- p.30 / Chapter 1.5.3 --- Mechanism of Disinfection --- p.31 / Chapter 1.5.4 --- Disinfection with Chlorine and Hypochlorite --- p.31 / Chapter 1.5.5 --- Chemistry of Chlorine Disinfection --- p.32 / Chapter 2. --- Objectives of Study --- p.35 / Chapter 3. --- Materials and Methods --- p.37 / Chapter 3.1 --- Sample Collection: --- p.37 / Chapter 3.2 --- Biological Studies of Activated Sludge Samples --- p.37 / Chapter 3.2.1 --- Microscopic Examination --- p.37 / Chapter 3.2.2 --- Isolation of Foam-Causing Filamentous Bacteria --- p.38 / Chapter 3.3 --- Physiology Studies of Nocardia amarae --- p.39 / Chapter 3.3.1 --- Growth Kinetics --- p.40 / Chapter 3.3.2 --- Effects of Fatty Acids on Nocardia amarae --- p.40 / Chapter 3.3.2.1 --- Fatty Acids as Sole Carbon Source --- p.41 / Chapter 3.3.2.2 --- Growth Stimulation --- p.42 / Chapter 3.3.2.3 --- Foam Test --- p.43 / Chapter 3.4 --- Fatty Acids Analysis --- p.43 / Chapter 3.4.1 --- Fatty Acid Extraction --- p.43 / Chapter 3.4.2 --- GC Analysis --- p.45 / Chapter 3.4.3 --- GC-MS Analysis --- p.46 / Chapter 3.5 --- Laboratory-Scale Activated Sludge Unit --- p.46 / Chapter 3.5.1 --- Set Up --- p.46 / Chapter 3.5.2 --- Performance Assessment of Laboratory-Scale Unit --- p.52 / Chapter 3.5.2.1 --- Physical Parameters --- p.52 / Chapter 3.5.2.2 --- Chemical Parameters --- p.54 / Chapter 3.5.2.3 --- Biological Parameters --- p.55 / Chapter 3.5.3 --- Anoxic Condition --- p.56 / Chapter 3.6 --- Toxicity Studies --- p.56 / Chapter 3.6.1 --- Comparative Toxicity Studies in Pure Culture --- p.56 / Chapter 3.6.2 --- Chlorination Studies of the Laboratory-Scale Unit --- p.58 / Chapter 3.6.3 --- Residual Chlorine Measurement --- p.58 / Chapter 3.7 --- Scanning Electron Microscopy --- p.60 / Chapter 4. --- Results --- p.61 / Chapter 4.1 --- Biological Studies of Activated Sludge --- p.61 / Chapter 4.1.1 --- Microscopic Examination --- p.61 / Chapter 4.1.2 --- Isolation of Foam-Causing Filamentous Bacteria --- p.61 / Chapter 4.2 --- Physiological Studies of Nocardia amarae --- p.65 / Chapter 4.2.1 --- Growth Kinetics --- p.65 / Chapter 4.2.2 --- Effects of Fatty Acids on Nocardia amarae --- p.69 / Chapter 4.2.2.1 --- Fatty Acids as Sole Carbon Source --- p.69 / Chapter 4.2.2.2 --- Growth Stimulation --- p.69 / Chapter 4.2.2.3 --- Foam Test --- p.69 / Chapter 4.3 --- Fatty Acids Analysis --- p.75 / Chapter 4.4 --- Laboratory-Scale Activated Sludge Unit --- p.80 / Chapter 4.4.1 --- Assessment of Performance of the Laboratory-Scale Unit --- p.80 / Chapter 4.4.2 --- Under Anoxic Condition --- p.80 / Chapter 4.5 --- Toxicity Studies --- p.85 / Chapter 4.5.1 --- Comparative Toxicity Studies in Pure Culture --- p.85 / Chapter 4.5.2 --- Chlorination Studies of Laboratory-Scale Unit --- p.85 / Chapter 4.5.3 --- Residual Chlorine Measurement --- p.91 / Chapter 5. --- Discussion --- p.94 / Chapter 5.1 --- Biological Studies of Activated Sludge Samples --- p.94 / Chapter 5.1.1 --- Microscopic Examination --- p.94 / Chapter 5.1.2 --- Isolation of Foam-Causing Filamentous Bacteria --- p.95 / Chapter 5.2 --- Physiological Studies of Nocardia amarae --- p.96 / Chapter 5.2.1 --- Growth Kinetics --- p.96 / Chapter 5.2.2 --- Effects of Fatty Acids on Nocardia amarae --- p.96 / Chapter 5.2.2.1 --- Fatty Acids as Sole Carbon Source --- p.96 / Chapter 5.2.2.2 --- Growth Stimulation --- p.97 / Chapter 5.2.2.3 --- Foam Test --- p.98 / Chapter 5.3 --- Fatty Acids Analysis --- p.99 / Chapter 5.4 --- Laboratory-Scale Activated Sludge Unit --- p.101 / Chapter 5.4.1 --- Assessment of Performance of the Laboratory-Scale Unit --- p.102 / Chapter 5.4.2 --- Under Anoxic Condition --- p.103 / Chapter 5.5 --- Toxicity Studies --- p.103 / Chapter 5.5.1 --- Comparative Toxicity Studies in Pure Culture --- p.103 / Chapter 5.5.2 --- Chlorination Studies of the Laboratory-Scale Unit --- p.105 / Chapter 6. --- Conclusion --- p.107 / Chapter 7. --- Summary --- p.108 / Chapter 8. --- References --- p.110

by Sonia, Tze Yan Lo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 132-147). / Abstracts in English and Chinese. / Acknowledgments --- p.i / Abstract --- p.ii / Table of Content --- p.iii / List of Figures --- p.ix / List of Tables --- p.xiii / List of Abbreviations --- p.xv / Terminology --- p.xvii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Objectives of sewage treatment process --- p.1 / Chapter 1.1.1 --- Types of treatment --- p.1 / Chapter 1.1.2 --- Activated sludge process --- p.2 / Chapter 1.1.3 --- Functioning of activated sludge process --- p.2 / Chapter 1.2 --- Common microbially mediated solid separation problems --- p.4 / Chapter 1.3 --- Bacterial foaming --- p.4 / Chapter 1.4 --- Factors enhancing foam production --- p.5 / Chapter 1.4.1 --- Substrates present in sewage --- p.6 / Chapter 1.4.2 --- Operating conditions --- p.8 / Chapter 1.4.3 --- Overpopulation of foaming bacteria --- p.8 / Chapter 1.5 --- Bacteria reported for foaming --- p.9 / Chapter 1.5.1 --- Foaming bacteria reported in different countries --- p.9 / Chapter 1.5.2 --- Nocardia Biology --- p.10 / Chapter 1.6 --- Metaboilsm of hydrophobic substances in sewage --- p.11 / Chapter 1.6.1 --- Metabolism of alkanes --- p.11 / Chapter 1.6.2 --- Metabolism of grease and oils --- p.11 / Chapter 1.6.3 --- Functions of lipids in the formation of bacterial foam --- p.11 / Chapter 1.7 --- Competition between floc-formers and foam-formers --- p.12 / Chapter 1.7.1 --- Interactions between microbial populations in activated sludge process --- p.12 / Chapter 1.7.2 --- Monod relationship and kinetic selection --- p.15 / Chapter 1.7.3 --- Effects of grease and oils in dominance of foaming bacteria --- p.17 / Chapter 1.8 --- Suggested mechanisms for bacterial foaming --- p.18 / Chapter 1.8.1 --- Mechanism suggested in early stage --- p.18 / Chapter 1.8.2 --- Froth flotation theory --- p.18 / Chapter 1.9 --- Problems from foaming --- p.21 / Chapter 1.10 --- Control of filamentous bacterial foaming --- p.22 / Chapter 2. --- Objectives of the study --- p.26 / Chapter 3. --- Materials and Methods --- p.27 / Chapter 3.1 --- Sample collection --- p.27 / Chapter 3.2 --- Isolation of major foaming and non-foaming bacteria --- p.27 / Chapter 3.2.1 --- Isolation of foaming bacteria --- p.27 / Chapter 3.2.2 --- Isolation of non-foaming bacteria --- p.30 / Chapter 3.3 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.31 / Chapter 3.4 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.32 / Chapter 3.5 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.34 / Chapter 3.6 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.37 / Chapter 3.7 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.38 / Chapter 3.8 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.39 / Chapter 3.9 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming abilities and settling abilities of activated sludge in batch cultures of foaming and non-foaming samples" --- p.43 / Chapter 4. --- Results --- p.48 / Chapter 4.1 --- Isolation of foaming and non-foaming bacteria --- p.48 / Chapter 4.1.1 --- Isolation of foaming bacteria --- p.48 / Chapter 4.1.2 --- Isolation of non-foaming bacteria --- p.48 / Chapter 4.2 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.56 / Chapter 4.3 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.56 / Chapter 4.4 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.60 / Chapter 4.4.1 --- Effects of fatty acids on Nocardia sp. CU-2 --- p.77 / Chapter 4.4.2 --- Effects of fatty acids on Aeromonas sp. CU-1 --- p.77 / Chapter 4.5 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.78 / Chapter 4.6 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.78 / Chapter 4.7 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.83 / Chapter 4.8 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming abilities and settling abilities of activated sludge in batch cultures of foaming and non-foaming samples" --- p.103 / Chapter 4.8.1 --- The filamentous growth of activated sludge --- p.103 / Chapter 4.8.2 --- Nocardial count --- p.103 / Chapter 4.8.3 --- Foam ratings --- p.107 / Chapter 4.8.4 --- Sludge settling ability --- p.107 / Chapter 5. --- Discussion --- p.114 / Chapter 5.1 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.114 / Chapter 5.2 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.114 / Chapter 5.2.1 --- Inhibition effects of MC fatty acids on growth of Nocardia sp. CU-2 --- p.115 / Chapter 5.2.2 --- Effects of fatty acids on specific growth rates --- p.115 / Chapter 5.2.3 --- Length of lag phase --- p.115 / Chapter 5.2.4 --- Kinetic selection of Nocardia sp. CU-2 and Aeromonas sp. CU-1 --- p.116 / Chapter 5.3 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.117 / Chapter 5.3.1 --- Growth of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in different media --- p.117 / Chapter 5.3.2 --- "Effects of fatty acids on Nocardia sp, CU-2" --- p.118 / Chapter 5.3.3 --- Effects of fatty acids on Aeromonas sp. CU-1 --- p.119 / Chapter 5.4 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.119 / Chapter 5.4.1 --- Effects of fatty acids in NB --- p.119 / Chapter 5.4.2 --- Effects of fatty acids in MM --- p.120 / Chapter 5.4.3 --- Effects of fatty acids in SS --- p.121 / Chapter 5.5 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.122 / Chapter 5.6 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.122 / Chapter 5.6.1 --- Differences in HA of Nocardia sp. CU-2 among three hydrocarbons --- p.122 / Chapter 5.6.2 --- Differences in HA of Nocardia sp. CU-2 among three different media --- p.123 / Chapter 5.6.3 --- Effects of fatty acids on HA of Nocardia sp. CU-2 --- p.123 / Chapter 5.7 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming and settling abilities of activated sludge in batch cultures" --- p.124 / Chapter 5.7.1 --- Abundance of filamentous microorganisms in activated sludge --- p.124 / Chapter 5.7.2 --- Nocardial count --- p.124 / Chapter 5.7.3 --- Foam ratings --- p.125 / Chapter 5.7.4 --- Sludge settling ability --- p.126 / Chapter 6. --- Conclusion --- p.127 / Chapter 7. --- Summary --- p.129 / Chapter 8. --- References --- p.132

by Stephen, Man-yuen Cheng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 124-141). / Abstract also in Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / List of Figures --- p.iv / List of Tables --- p.ix / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The development of dyes --- p.1 / Chapter 1.2 --- The chemistry of azo dyes --- p.2 / Chapter 1.3 --- "Evaluation of dyes submitted under the ""Toxic Substances Control Act"" new chemicals programme" --- p.6 / Chapter 1.4 --- Environmental concerns of dyes --- p.7 / Chapter 1.5 --- Decolorization techniques --- p.11 / Chapter 1.5.1 --- Activated sludge process --- p.11 / Chapter 1.5.2 --- Chlorination --- p.12 / Chapter 1.5.3 --- Fenton's reaction --- p.13 / Chapter 1.5.4 --- Ozonation --- p.13 / Chapter 1.5.5 --- Adsorption by activated carbon --- p.13 / Chapter 1.5.6 --- Chemical flocculation --- p.14 / Chapter 1.5.7 --- Coagulation --- p.14 / Chapter 1.5.8 --- Advance Oxidation Process --- p.15 / Chapter 1.5.8a --- Photocatalytic activation --- p.17 / Chapter 1.5.8b --- Enhancement of reaction rates of photocatalytic reaction --- p.21 / Chapter 1.5.9 --- Biosorption of azo dyes by Pseudomonas sp. K-l --- p.23 / Chapter 1.6 --- Water pollution in Hong Kong --- p.24 / Chapter 1.7 --- Purpose of study --- p.24 / Chapter 2 --- Objectives --- p.27 / Chapter 3 --- Materials and Methods --- p.28 / Chapter 3.1 --- Materials --- p.28 / Chapter 3.1.1 --- Azo dyes --- p.28 / Chapter 3.1.2 --- Biosorbent --- p.28 / Chapter 3.1.3 --- Chemicals --- p.28 / Chapter 3.2 --- Photocatalytic reactor --- p.31 / Chapter 3.3 --- Determination of the peak absorbance of five azo dyes at different pH --- p.31 / Chapter 3.4 --- Determination of dye concentration by measuring at peak absorbance --- p.37 / Chapter 3.5 --- Determination of pseudo-first-order rate constant --- p.37 / Chapter 3.6 --- Effect of initial concentration of procion red MX-5B on photocatalytic degradation --- p.39 / Chapter 3.7 --- Effect of initial concentration of hydrogen peroxide on photocatalytic degradation of procion red MX-5B --- p.40 / Chapter 3.8 --- Effect of initial pH on the photocatalytic degradation of procion red MX-5B --- p.40 / Chapter 3.9 --- Effect of initial temperature on the photocatalytic degradation of procion red MX-5B --- p.40 / Chapter 3.10 --- Effect of titanium dioxide on the photocatalytic degradation of procion red MX-5B --- p.40 / Chapter 3.11 --- Effect of UV intensity in the photocatalytic degradation of procion red MX-5B --- p.41 / Chapter 3.12 --- Degradation kinetics of different dyes --- p.41 / Chapter 3.13 --- Degradation of 40 mg/L of procion red MX-5B under optimized conditions --- p.41 / Chapter 3.14 --- "Degradation of 1,000 mg/L of procion red MX-5B under optimized conditions" --- p.42 / Chapter 3.15 --- Temporal change of the concentration of procion red MX-5B in calcium alginate beads --- p.42 / Chapter 3.16 --- "Temporal change of the concentration of procion red MX-5B in alginate beads of 5,000 mg/L of Ti02" --- p.43 / Chapter 3.17 --- "Temporal change of the concentration of procion red MX-5B in alginate beads of 10,000 mg/L of Ti02" --- p.43 / Chapter 3.18 --- Effect of the concentration of titanium dioxide in alginate beads in the photocatalytic degradation of procion red MX-5B --- p.45 / Chapter 3.19 --- "Effect of hydrogen peroxide in the photocatalytic degradation of procion red MX-5B in 5,000 mg/L of Ti02-alginate beads" --- p.47 / Chapter 3.20 --- "Temporal change of the concentration of procion red MX-5B in alginate beads with 5,000 mg/L of Ti02" --- p.47 / Chapter 3.21 --- "Effect of biomass of Pseudomonas sp. K1 on the photocatalytic degradation of procion red MX-5B in alginate beads with 5,000 mg/L of Ti02" --- p.48 / Chapter 3.22 --- Diffuse reflectance-IR spectroscopic analysis of degradation product(s) --- p.49 / Chapter 3.23 --- Nuclear magnetic resonance (NMR) spectroscopic analysis of degradation products --- p.49 / Chapter 3.24 --- Toxicological evaluation of degradation products using Microtox® test --- p.51 / Chapter 4 --- Result --- p.54 / Chapter 4.1 --- Biosorption of dyes by Pseudomonas sp. K1 --- p.54 / Chapter 4.2 --- UV intensities of the eight Cole-Parmer UV lamps at 365 nm --- p.54 / Chapter 4.3 --- Determination of the peak absorbance of five azo dyes at different pH using scanning spectrophotometer --- p.54 / Chapter 4.4 --- Determination of dye concentration by measuring at peak absorbance --- p.66 / Chapter 4.5 --- Effect of initial concentration of procion red MX-5Bin photocatalytic degradation rate --- p.66 / Chapter 4.6 --- Effect of initial concentration of hydrogen peroxide on the photocatalytic degradation of procion red MX-5B --- p.73 / Chapter 4.7 --- Effect of initial pH on photocatalytic degradation of procion red MX-5B --- p.73 / Chapter 4.8 --- Effect of initial temperature on photocatalytic degradation of procion red MX-5B --- p.73 / Chapter 4.9 --- Effect of titanium dioxide on photocatalytic degradation of procion red MX-5B --- p.77 / Chapter 4.10 --- Effect of UV intensity on photocatalytic degradation of procion red MX-5B --- p.77 / Chapter 4.11 --- Photocatalytic degradation kinetics of different azo dyes --- p.77 / Chapter 4.12 --- Photocatalytic degradation of 40 mg/L of reactive red241 under optimized conditions --- p.77 / Chapter 4.13 --- Photocatalytic degradation of 40 mg/L procion red MX-5B under optimized conditions --- p.81 / Chapter 4.14 --- "Photocatalytic degradation of 1,000 mg/L of procion red MX-5B under optimized conditions" --- p.81 / Chapter 4.15 --- Temporal change of the concentration of procion red MX-5B in calcium alginate beads --- p.81 / Chapter 4.16 --- "Temporal changes of the concentration of procion red MX-5B in 5,000 mg/L of Ti02-alginate beads" --- p.85 / Chapter 4.17 --- "Temporal change of the concentration of procion red MX-5B in 10,000 mg/L of Ti02-alginate beads" --- p.85 / Chapter 4.18 --- Effect of the concentration of titanium dioxide in alginate beads in the photocatalytic degradation of procion red MX-5B --- p.89 / Chapter 4.19 --- "Effect of hydrogen peroxide in the photocatalytic degradation of procion red MX-5B in 5,000 mg/L of Ti02-alginate beads" --- p.89 / Chapter 4.20 --- "Temporal change of the concentration of procion red MX-5Bin alginate beads with 5,000 mg/L of Ti02" --- p.89 / Chapter 4.21 --- "Effect ofbiomass of Pseudomonas sp. K1 on the photocatalytic degradation of procion red MX-5B in 5,000 mg/L of Ti02-alginate beads" --- p.93 / Chapter 4.22 --- Degradation products analysis using diffuse reflectance-IR spectroscopy --- p.93 / Chapter 4.23 --- Degradation products analysis using nuclear magnetic resonance (NMR) --- p.101 / Chapter 4.24 --- Toxicological evaluation of degradation products using Microtox® test --- p.101 / Chapter 5 --- Discussion --- p.104 / Chapter 5.1 --- Biosorption of azo dyes in Pseudomonas sp. K-l --- p.104 / Chapter 5.2 --- Optimization of photocatalytic degradation of azo dyes --- p.105 / Chapter 5.2.1 --- Effect of initial concentration of procion red MX-5B on the photocatalytic degradation --- p.105 / Chapter 5.2.2 --- Effect of initial concentration of hydrogen peroxide on the photocatalytic degradation --- p.106 / Chapter 5.2.3 --- Effect of initial pH on the photocatalytic degradation --- p.107 / Chapter 5.2.4 --- Effect of initial temperature on the photocatalytic degradation --- p.108 / Chapter 5.2.5 --- Effect of titanium dioxide on the photocatalytic degradation --- p.109 / Chapter 5.2.6 --- Effect of UV intensity on the photocatalytic degradation --- p.110 / Chapter 5.2.7 --- Degradation kinetics of different dyes --- p.111 / Chapter 5.2.8 --- Optimized conditions for PCO of reactive red 241 and procion red --- p.112 / Chapter 5.3 --- Immobilization of titanium dioxide and Pseudomonas sp. K-l in alginate beads --- p.113 / Chapter 5.3.1 --- Temporal changes of the concentration of dye in alginate beads --- p.113 / Chapter 5.3.2 --- Effect of titanium dioxide in alginate beads in PCO --- p.114 / Chapter 5.3.3 --- Effect of hydrogen peroxide in alginate beads in PCO --- p.115 / Chapter 5.3.4 --- "Temporal change of dye concentration in alginate beads of 5,000 mg/L" --- p.115 / Chapter 5.3.5 --- Effect of biomass of Pseudomonas sp. K-l in alginate beads on the PCO of dye --- p.115 / Chapter 5.4 --- Diffuse reflectance IR spectroscopic analysis of degradation products --- p.116 / Chapter 5.5 --- 1HNMR analysis of degradation products --- p.119 / Chapter 5.6 --- Toxicological evaluation of degradation products using Microtox® test --- p.120 / Chapter 5.7 --- Application --- p.121 / Chapter 6 --- Conclusion --- p.122 / Chapter 7 --- References --- p.124 / Appendix 1 --- p.142 / Appendix 2 --- p.143

by So Lai Man, Rachel. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 83-103). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.ix / Chapter 1. --- Literature Review --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Overview of metal ions pollution --- p.2 / Chapter 1.3 --- Treatment of metal ions in wastewater --- p.4 / Chapter 1.3.1 --- Conventional methods --- p.4 / Chapter 1.3.2 --- Microbial methods --- p.5 / Chapter 1.4 --- Phytoremediation --- p.6 / Chapter 1.4.1 --- Rhizofiltration --- p.10 / Chapter 1.4.2 --- Mechanisms of metal ion removal by plant root --- p.12 / Chapter 1.5 --- Using water hyacinth for wastewater treatment --- p.15 / Chapter 1.5.1 --- Biology of water hyacinth --- p.15 / Chapter 1.5.2 --- Water hyacinth based systems for wastewater treatment --- p.21 / Chapter 1.6 --- Biology of rhizosphere --- p.23 / Chapter 2. --- Objectives --- p.26 / Chapter 3 --- Materials and Methods --- p.28 / Chapter 3.1 --- Metal ion stock solution --- p.28 / Chapter 3.2 --- Plant material and growth conditions --- p.28 / Chapter 3.2.1 --- Preparation of Hoagland solution --- p.28 / Chapter 3.3 --- Metal ion resistance of water hyacinth --- p.31 / Chapter 3.4 --- Effect of metal ion concentration on the bacteria population --- p.31 / Chapter 3.4.1 --- Minimal medium (MM) --- p.31 / Chapter 3.5 --- Isolation of rhizospheric metal ion-resistant bacteria --- p.34 / Chapter 3.6 --- Metal ion removal capacity of isolated bacteria --- p.34 / Chapter 3.7 --- Colonization efficiency of a metal ion-adsorbing bacterium onto the root --- p.35 / Chapter 3.7.1 --- Suppression of the bacterial population in the rhizosphere by an antibiotic --- p.35 / Chapter 3.7.2 --- Colonization efficiency --- p.36 / Chapter 3.8 --- Effect of colonizing the metal ion-adsorbing bacteria on the metal ion removal capacity of roots --- p.37 / Chapter 4. --- Results --- p.38 / Chapter 4.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizo spheric bacteria --- p.38 / Chapter 4.1.1 --- Metal ion resistance of water hyacinth --- p.38 / Chapter 4.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria --- p.43 / Chapter 4.1.3 --- Selection for optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.43 / Chapter 4.2 --- Screening for bacterial strain with high metal ion resistance and removal capacity --- p.46 / Chapter 4.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.46 / Chapter 4.2.2 --- Isolation of the natural bacterial population in rhizosphere --- p.50 / Chapter 4.2.3 --- Determination of the metal ion removal capacity of rhizospheric metal ion-resistant bacterial strains --- p.52 / Chapter 4.2.4 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities of Cu2+-resistant bacterial strains" --- p.53 / Chapter 4.3 --- Effect of inoculating Cu2+-resistant bacterial strain to the rhizosphere on the metal ion removal capacity of the root --- p.59 / Chapter 4.3.1 --- Bactericidal efficiency of oxytetracycline --- p.59 / Chapter 4.3.2 --- Effect of inoculating Cu2+-adsorbing bacterial cells into the rhizosphere --- p.62 / Chapter 4.3.3 --- Effect of bacterial cell density of inoculum on colonizing efficiency --- p.63 / Chapter 4.3.4 --- Colonizing efficiency and metal ion removal capacity of root by direct inoculation of metal ion-adsorbing bacterial cells into metal ion solution or pre-inoculation in Hoagland solution --- p.64 / Chapter 4.3.5 --- Effect of inoculating Strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.64 / Chapter 5. --- Discussion --- p.69 / Chapter 5.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.69 / Chapter 5.1.1 --- Metal resistance of water hyacinth --- p.69 / Chapter 5.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria population --- p.70 / Chapter 5.1.3 --- Selection for optimum concentration --- p.70 / Chapter 5.2 --- Screening for high metal ion-resistant and -removal bacterial strains --- p.71 / Chapter 5.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.71 / Chapter 5.2.2 --- Select metal ion-resistant bacterial strain from the natural population in the rhizosphere --- p.72 / Chapter 5.2.3 --- Determination of the metal ion removal capacity of respective metal ion-resistant bacterial strain --- p.72 / Chapter 5.3 --- Effect of inoculating Cu2+-resistant bacterial strain in the rhizosphere on the metal ion removal capacity of the root --- p.74 / Chapter 5.3.1 --- Bactericidal efficiency of oxytetracycline --- p.74 / Chapter 5.3.2 --- Effect of inoculating Cu2十-adsorbing bacterial cells into the rhizosphere --- p.75 / Chapter 5.3.3 --- Effect inoculum cell density on the colonizing efficiency --- p.76 / Chapter 5.3.4 --- Comparison of colonizing efficiency and metal ion removal capacity of root by direct inoculation metal ion-adsorbing bacterial cells into metal solution or pre-inoculationin Hoagland solution --- p.77 / Chapter 5.3.5 --- Effect of inoculating strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.78 / Chapter 5.4 --- Limitation and future development --- p.79 / Chapter 6. --- Conclusion --- p.81 / Chapter 7. --- References --- p.83