The increasing level and dispersion of toxic chemicals in the environment has stimulated a need for accurate methods capable of detecting and quantifying the activity of toxicants. The primary objective of this study was to determine, through in vitro tests, the potential of three purified enzymes: α-chymotrypsin, acid phosphatase, and carbonic anhydrase for use in the early assessment of toxicants at environmentally significant levels. Activities of α-chymotrypsin and acid phosphatase were measured spectrophotometrically, while carbonic anhydrase activities were determined through monitoring a pH change. The chemical agents investigated included several heavy metals, common herbicides and pesticides, and various environmentally significant anions. In addition, several techniques were explored to amplify enzyme response to chemical agents. The results of the study demonstrated that α-chymotrypsin did not significantly respond to cadmium, nickel, or 2,4-D, and consequently, does not appear to be useful in indicating potential toxicity problems associated with these agents. The acid phosphatase enzyme system appears to be useful in signaling the presence of low levels of certain anions (fluoride at 0.45 mg/ℓ and nitrate at 7.3 mg/ℓ), but does not appear to have potential for detecting toxic activity due to cadmium, nickel, or 2,4-D. Enzyme inhibition induced by fluoride at 37°C was not altered by changing the assay temperature to 50°C. The results of the experiments with carbonic anhydrase show that the enzyme does not appear to be affected by cadmium or nickel ions. However, enzyme activity was inhibited by fluoride (4.5 mg/ℓ), sulfide (0.5 mg/ℓ), and nitrate (73 mg/ℓ). Enzyme inhibition was also induced by 10 mg/ℓ of atrazine, malathion, or carbaryl, and 150 to 500 mg/ℓ of 2,4-D. Inhibitory effects induced by sulfanilamide appeared to be slightly enhanced by the addition of Cd²⁺, Ni²⁺, or Zn²⁺ cations. These findings, although preliminary, suggest that carbonic anhydrase demonstrates potential for signaling the presence of anions, and appears to be useful in indicating potential toxicity problems due to pesticides and herbicides. / Master of Science

by Chung Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 127-141). / Text in English; abstracts in English and Chinese. / by Chung Ho Yan. / Acknowledgments --- p.i / Abstract --- p.ii / Table of Contents --- p.v / List of Figures --- p.xi / List of Plates --- p.xiv / List of Tables --- p.xv / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Textile-Dyeing Industry in Hong Kong --- p.1 / Chapter 1.2 --- Processes Involved in Dyeing Industry --- p.3 / Chapter 1.2.1 --- Desizing --- p.3 / Chapter 1.2.2 --- Scouring --- p.3 / Chapter 1.2.3 --- Bleaching --- p.3 / Chapter 1.2.4 --- Mercerizing --- p.4 / Chapter 1.2.5 --- Dyeing and Printing --- p.4 / Chapter 1.2.6 --- Finishing --- p.4 / Chapter 1.3 --- Characterization of Wastewater of Dyeing Industry --- p.5 / Chapter 1.4 --- Toxicity of Effluent from Textile-Dyeing Industry --- p.9 / Chapter 1.5 --- Related Environmental Legislation --- p.9 / Chapter 1.6 --- Chemical Specific Approach and Toxicity Based Approach --- p.11 / Chapter 1.7 --- Whole-Effluent Toxicity (WET) Test --- p.13 / Chapter 1.8 --- Toxicity Identification Evaluation --- p.14 / Chapter 1.8.1 --- Phase I - Toxicity Characterization --- p.15 / Chapter 1.8.2 --- Phase II - Toxicity Identification --- p.15 / Chapter 1.8.3 --- Phase III - Toxicity Confirmation --- p.18 / Chapter 1.9 --- Toxicity Identification Evaluation on Effluent from Textile-Dyeing Industry --- p.19 / Chapter 1.10 --- Organisms Used for Toxicity Identification Evaluation --- p.20 / Chapter 1.11 --- Selection of Organisms for Bioassays --- p.20 / Chapter 2. --- OBJECTIVES --- p.24 / Chapter 3. --- MATERIALS AND METHODS --- p.25 / Chapter 3.1 --- Sources of Samples --- p.25 / Chapter 3.2 --- Whole Effluent Toxicity Test - Baseline Toxicity Test --- p.28 / Chapter 3.2.1 --- Microtox® test --- p.28 / Chapter 3.2.2 --- "Survival test of the marine amphipod, Hyale crassicornis" --- p.29 / Chapter 3.2.3 --- "Survival test of the brine shrimp, Artemia franciscana" --- p.33 / Chapter 3.2.4 --- "Survival test of the freshwater water flea, Daphnia magna" --- p.36 / Chapter 3.3 --- Toxicity Identification Evaluation ´ؤ Phase I Toxicity Characterization --- p.40 / Chapter 3.3.1 --- pH adjustment filtration test --- p.41 / Chapter 3.3.2 --- pH adjustment aeration test --- p.42 / Chapter 3.3.3 --- pH adjustment cation exchange test --- p.43 / Chapter 3.3.4 --- pH adjustment anion exchange test --- p.44 / Chapter 3.3.5 --- pH adjustment C18 solid phase extraction (C18 SPE) test --- p.45 / Chapter 3.3.6 --- pH adjustment XAD-2 solid phase extraction (XAD-2 SPE) test --- p.46 / Chapter 3.4 --- Toxicity Identification Evaluation - Phase II Toxicity Identification --- p.47 / Chapter 3.4.1 --- Determination of anions --- p.48 / Chapter 3.5 --- Toxicity Identification Evaluation ´ؤ Phase III Toxicity Confirmation --- p.50 / Chapter 3.5.1 --- Mase balance test --- p.50 / Chapter 3.5.2 --- Spiking test --- p.51 / Chapter 4. --- RESULTS --- p.52 / Chapter 4.1 --- Characteristics of Samples --- p.52 / Chapter 4.2 --- Whole Effluent Toxicity Test - Baseline Toxicity Test --- p.52 / Chapter 4.2.1 --- Toxicity of effluent sample determined by the Microtox® test --- p.52 / Chapter 4.2.2 --- Toxicity of effluent samples determined by Hyale crassicornis survival test --- p.52 / Chapter 4.2.3 --- Toxicity of effluent samples determined by Artemia franciscana survival test --- p.57 / Chapter 4.2.4 --- Toxicity of effluent samples determined by Daphnia magna survival test --- p.51 / Chapter 4.3 --- Toxicity Identification Evaluation - Phase I Toxicity Characterization --- p.57 / Chapter 4.3.1 --- Toxicity characterization of effluent samples determined by Hyale crassicornis survival test --- p.60 / Chapter 4.3.2 --- Toxicity characterization of effluent samples determined by Artemia franciscana survival test --- p.68 / Chapter 4.3.3 --- Toxicity characterization of effluent samples determined by Daphnia magna survival test --- p.68 / Chapter 4.4 --- Toxicity Identification Evaluation ´ؤ Phase II Toxicity Identification --- p.72 / Chapter 4.4.1 --- Baseline anion concentrations in effluent samples --- p.75 / Chapter 4.4.2 --- Sample1 --- p.75 / Chapter 4.4.3 --- Sample2 --- p.75 / Chapter 4.4.4 --- Sample3 --- p.75 / Chapter 4.4.5 --- Sample4 --- p.81 / Chapter 4.4.6 --- Sample5 --- p.81 / Chapter 4.4.7 --- Sample6 --- p.81 / Chapter 4.5 --- Toxicity Identification Evaluation 一 Phase III Toxicity Confirmation --- p.85 / Chapter 4.5.1 --- Mass balance test results --- p.85 / Chapter 4.5.2 --- Spiking test results --- p.96 / Chapter 5. --- DISCUSSION --- p.102 / Chapter 5.1 --- Whole Effluent Toxicity Test ´ؤ Baseline Toxicity Test --- p.102 / Chapter 5.1.1 --- Toxicity of effluent sample determined by the Microtox® test --- p.102 / Chapter 5.1.2 --- Toxicity of effluent samples determined by Hyale crassicornis survival test --- p.103 / Chapter 5.1.3 --- Toxicity of effluent samples determined by Artemia franciscana survival test --- p.104 / Chapter 5.1.4 --- Toxicity of effluent samples determined by Daphnia magna survival test --- p.104 / Chapter 5.2 --- Toxicity Identification Evaluation ´ؤ Phase I Toxicity Characterization --- p.105 / Chapter 5.2.1 --- pH adjustment filtration test --- p.105 / Chapter 5.2.2 --- pH adjustment aeration test --- p.106 / Chapter 5.2.3 --- pH adjustment cation exchange test --- p.106 / Chapter 5.2.4 --- pH adjustment anion exchange test --- p.106 / Chapter 5.2.5 --- pH adjustment C18 solid phase extraction (C18 SPE) test --- p.107 / Chapter 5.2.6 --- pH adjustment XAD-2 solid phase extraction (XAD-2 SPE) test --- p.107 / Chapter 5.3 --- Toxicity Identification Evaluation - Phase II Toxicity Identification --- p.107 / Chapter 5.3.1 --- Efficiency on chemical reduction of pH adjustment filtration test --- p.109 / Chapter 5.3.2 --- Efficiency on chemical reduction of pH adjustment aeration test --- p.109 / Chapter 5.3.3 --- Efficiency on chemical reduction of pH adjustment cation exchange test --- p.109 / Chapter 5.3.4 --- Efficiency on chemical reduction of pH adjustment anion exchange test --- p.109 / Chapter 5.3.5 --- Efficiency on chemical reduction of pH adjustment CI8 SPE test --- p.109 / Chapter 5.3.6 --- Efficiency on chemical reduction of pH adjustment XAD-2 SPE test --- p.110 / Chapter 5.4 --- Toxicity Identification Evaluation - Phase III Toxicity Confirmation --- p.110 / Chapter 5.4.1 --- Mass balance test results --- p.110 / Chapter 5.4.2 --- Spiking test results --- p.114 / Chapter 5.5 --- Comparison of Toxicant(s) Identified in the Six Dyeing Industrial Effluents --- p.117 / Chapter 5.6 --- Toxicant(s) Identified in Textile-Dyeing Industrial Effluent --- p.119 / Chapter 5.7 --- "Sources, Fate and Treatment of Sulfite Ion" --- p.120 / Chapter 5.8 --- Toxicity of Sulfite Ion --- p.121 / Chapter 5.9 --- Effect of Salinity on the Toxicity of Sulfite Ion --- p.122 / Chapter 5.10 --- Recommendation --- p.123 / Chapter 6. --- CONCLUSIONS / Chapter 7. --- REFERENCES / Chapter 8. --- APPENDICES