No description available.

AECI Bioproducts (Bioproducts) is part of an industrial complex located at Umbogintwini, approximately 26 km south of Durban, Kwazulu-Natal. This system was selected for water pinch investigation, as it is one of the major users of freshwater on the complex and hence discharges a related quantity of wastewater, amounting to approximately 400 ML per annum. Bioproducts is a manufacturer of l-lysine, which is an animal feed additive. Water stream flowrate and purity data, as well as operating cost information, were obtained from plant records at AECI Bioproducts. Limiting flowrate and purity conditions for the water-using operations were established from a mass balance over the entire system using the Linnhoff-March software, WaterTracker. Subject to the specified constraints and operating costs, the problem was to determine the design of the water-using subsystem. No treatment plants were included in the study, as none exist at the facility. Three scenarios were investigated, which examined the operating variability of one of the evaporators on the site (the AS evaporator), which produces a condensate source of variable purity. The operating cost target and network design for each scenario was determined using the Linnhoff-March software, WaterPinch. Alterations from current operating practice were identified and associated savings (water-using network operating cost and freshwater flowrate) were highlighted. A robust optimal design was identified, with a recycle, which was consistent for all scenarios investigated. The degree of reuse of the AS evaporator condensate source was determined to be dependent on the purity of the source. The limiting constraint was identified at the sea pipeline, for suspended solids (SS): a prohibitively low discharge concentration constraint was identified as posing the major obstacle for saving. The potential for saving was investigated by incrementing the SS concentration constraint and subsequently the free and saline ammonia (FSA) constraint and allowing for the broth effluent to be discharged via the sea pipeline (which was previously disallowed by an effluent exemption). Although relatively small savings were identified through process integration (from 0.61% to 1.56% of the water-using network operating cost), the analysis identified a potential saving of over 70% of the water-using network operating cost, with relaxation of the sea pipeline SS and FSA constraint. / Theses (M.Sc.)-University of Natal, Durban, 2002.

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

High-Gradient Magnetic Separation (HGMS) is a powerful separation process that has great potential for industrial wastewater treatment, particularly for the removal and recovery of paramagnetic colloidal particles. The chief advantages of HGMS are that the separation is reversible and potentially selective. However, these advantages are compromised if non-magnetic filtration mechanisms influence significantly the capture of particles. The objective of this study was to identify the chief mechanisms responsible for the removal of ferric oxide (Fe2O3) from water by an HGMS process. This objective was achieved by measuring the effects of applied magnetic induction, collector radius, and fluid velocity on the removal efficiency (RE) of a stainless-steel filter column. These factors were tested on the removal of bare Fe2O3 particles and particles treated with a surfactant (sodium dodecyl sulfate, SDS). The results were compared to the predictions of a trajectory model which simulates particle capture by a magnetic force. The experimental results show that non-magnetic force mechanisms are primarily responsible for the removal of bare Fe2O3 particles for the experimental conditions used in this work. For these particles, the three factors tested had no significant effect on the RE, and 90.1% of the particles were removed without a magnetic force. These results differed sharply from modeling predictions. However, the magnetic force mechanism is primarily responsible for the removal of surfactant-treated Fe2O3 particles. The three factors investigated had a marked effect on the RE, and only 10.8% of the particles were removed without a magnetic force. An increase in magnetic induction from 0.2 to 0.5 T increased the RE from 79.9 to 93.4 %; a decrease in wire radius from 49 to 15 Ym increased the RE from 60.2 to 93.4%, and a decrease in fluid velocity from 0.5 to 0.1 cm/s increased the RE from 69.5 to 95.3%. These results agreed closely with the model predictions.This study demonstrates that by reducing the effect of attractive non-magnetic forces on filtration, surfactant treatment of colloidal particles can potentially preserve and enhance these two key advantages, i.e., regeneration and selectivity of HGMS processes.

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