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

by Sze Kwok Fung Calvin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 118-130). / Acknowledgement --- p.i / Abstract --- p.ii / Content --- p.iv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Literature review --- p.1 / Chapter 1.1.1 --- Heavy metals in the environment --- p.1 / Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.2 / Chapter 1.1.3 --- Electroplating industry in Hong Kong --- p.6 / Chapter 1.1.4 --- Chemistry and toxicity of copper in the environment --- p.7 / Chapter 1.1.5 --- Methods of removal of heavy metal from industrial effluent --- p.9 / Chapter A. --- Physico-chemical methods --- p.9 / Chapter B. --- Biological methods --- p.9 / Chapter 1.1.6 --- Methods of recovery of heavy metal from metal-loaded biosorbent --- p.17 / Chapter 1.1.7 --- The physico-chemical properties of magnetites --- p.18 / Chapter 1.1.8 --- Magnetites for water and wastewater treatment --- p.19 / Chapter 1.1.9 --- Immobilized cell technology --- p.24 / Chapter 1.1.10 --- Stirrer-tank bioreactor --- p.26 / Chapter 1.2 --- Objectives of the present study --- p.28 / Chapter 2. --- Materials and Methods --- p.30 / Chapter 2.1 --- Selection of copper-resistant bacteria --- p.30 / Chapter 2.2 --- Culture media and chemicals --- p.30 / Chapter 2.3 --- Growth of the bacterial cells --- p.32 / Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.32 / Chapter 2.4.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.34 / Chapter 2.4.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.34 / Chapter 2.5 --- Copper ion uptake experiments --- p.35 / Chapter 2.6 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.35 / Chapter 2.7 --- Transmission electron micrograph and scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.36 / Chapter 2.7.1 --- Transmission electron micrograph --- p.36 / Chapter 2.7.2 --- Scanning electron micrograph --- p.37 / Chapter 2.8 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.37 / Chapter 2.9 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.38 / Chapter 2.9.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.38 / Chapter 2.9.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.39 / Chapter 2.10 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.39 / Chapter 2.10.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.39 / Chapter 2.10.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.40 / Chapter 2.11 --- Statistical analysis of data --- p.43 / Chapter 3. --- Results --- p.44 / Chapter 3.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.44 / Chapter 3.1.1 --- Effects of cells to magnetites ratio --- p.44 / Chapter 3.1.2 --- Effects of pH --- p.44 / Chapter 3.1.3 --- Effects of temperature --- p.44 / Chapter 3.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.49 / Chapter 3.3 --- Copper ion uptake experiments --- p.49 / Chapter 3.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.49 / Chapter 3.4.1 --- Effects of pH --- p.49 / Chapter 3.4.2 --- Effects of temperature --- p.53 / Chapter 3.4.3 --- Effects of retention time --- p.53 / Chapter 3.4.4 --- Effects of cations --- p.53 / Chapter 3.4.5 --- Effects of anions --- p.57 / Chapter 3.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62 / Chapter 3.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62 / Chapter 3.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68 / Chapter 3.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68 / Chapter 3.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.68 / Chapter 3.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.74 / Chapter 3.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.74 / Chapter 3.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.74 / Chapter 3.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.81 / Chapter 4. --- Discussion --- p.89 / Chapter 4.1 --- Selection of copper-resistant bacteria --- p.89 / Chapter 4.2 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.89 / Chapter 4.2.1 --- Effects of cells to magnetites ratio --- p.89 / Chapter 4.2.2 --- Effects of pH --- p.90 / Chapter 4.2.3 --- Effects of temperature --- p.91 / Chapter 4.2.4 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.92 / Chapter 4.3 --- Copper ion uptake experiments --- p.93 / Chapter 4.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.94 / Chapter 4.4.1 --- Effects of pH --- p.95 / Chapter 4.4.2 --- Effects of temperature --- p.96 / Chapter 4.4.3 --- Effects of retention time --- p.97 / Chapter 4.4.4 --- Effects of cations --- p.98 / Chapter 4.4.5 --- Effects of anions --- p.101 / Chapter 4.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.101 / Chapter 4.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.102 / Chapter 4.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.103 / Chapter 4.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.104 / Chapter 4.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.104 / Chapter 4.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.105 / Chapter 4.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.107 / Chapter 4.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.107 / Chapter 4.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.108 / Chapter 5. --- Conclusion --- p.110 / Chapter 6. --- Summary --- p.112 / Chapter 7. --- References --- p.115

[Truncated abstract] The use of constructed wetlands for tertiary purification of municipal wastewater has received increasing attention around the world because direct discharge of secondary-treated municipal wastewater to water bodies has caused eutrophication. Plant species selection and vegetation management may enhance nutrient removal efficiency in constructed wetlands. However, there is a lack of knowledge on the relations between plant growth and nutrient removal efficiency in constructed wetlands. The objective of this study is to better understand how plant growth and resource allocation are influenced by nutrients in wastewater and how nutrient removal efficiencies are affected by plant species and vegetation management. The preliminary experiment was conducted to select macrophytes, especially ornamental species, to grow in the wastewater in the wetland microcosms. Ten plant species, comprising six ornamental species: Alocasia macrorrhiza, Canna indica, Iris louisiana, Lythrum sp., Zantedeschia aethiopica, Zantedeschia sp., and four sedge species: Baumea articulate, Baumea juncea, Carex tereticaulis and Schoenoplectus validus, were planted in the wetland microcosms and fed a simulated wastewater solution in the concentrations similar to the secondary-treated municipal wastewater. C. indica has shown vigorous and healthy growth, and a relatively high potential of rooting-zone aeration and nutrient removal efficiency. B. articulata and S. validus also showed relatively high nutrient removal efficiency. ... The high nutrient availability and optimum N/P ratio were required for stimulating plant growth, resulting in allocation of more resources to above-ground tissues compared to below-ground parts, and enhancing nutrient removal efficiency. Nutrient removal efficiencies were significantly influenced by growth of C. indica and S. validus, nutrient loading rates and N/P ratios in the wastewater. The nutrient uptake kinetics of C. indica and S. validus were investigated to elucidate the differences in nutrient uptake between species. Wetland plant species have shown differential nutrient uptake efficiency and different preferences for inorganic N source, with C. indica preferring NO3-N and S. validus preferring NH4-N. C. indica had greater capacity than S. validus to take up PO4-P when the concentration of PO4-P in the solution was relatively low, whereas S. validus was more capable than C. indica to take up NO3-N when the concentration of NO3-N in the solution was relatively low. The PO4-P uptake capacity was higher in younger than older plants. Overall, the study has suggested that different plant species have differential capacity to take up nutrients. In addition to nutrient uptake, plants have significant other roles in terms of nutrient removal from the wastewater (such as leaking oxygen into the rhizosphere in which oxidation of substances like ammonia can occur). The properly high nutrient availability and optimum N/P ratio are required to stimulate the plant growth, resulting in enhancing the treatment performance in the wetlands. These findings have important implications for improving our ability to engineer ecological solutions to the problems associated with nutrient-rich wastewater.

O presente trabalho de pesquisa teve como objetivo principal avaliar a remoção de fitoplancton e microcistina em cinco fluxogramas de tratamento de água para abastecimento, que tiveram como seqüência básica as etapas de coagulação, floculação, flotação por ar dissolvido e filtração, complementados com oxidação química em diferentes pontos da seqüência básica de tratamento estabelecida. Os ensaios foram realizados em escala de laboratório, utilizando água de estudo preparada mediante a mistura de água coletada no reservatório de Barra Bonita, no Estado de São Paulo, e cultura com elevada concentração de microcistina preparada em laboratório. A concentração de microcistina na água de estudo foi mantida no intervalo de 14 a 17 µg/L. O cloreto férrico foi utilizado como agente coagulante, o permanganato de potássio e o cloro, na forma de hipoclorito de sódio, foram utilizados como agentes oxidantes. Foi observada eficiência de remoção de fitoplancton de cerca de 99,9% devido às etapas de coagulação, floculação e flotação por ar dissolvido e, conseqüentemente, remoção de microcistina contida no interior das células íntegras. A oxidação com cloro realizada após a filtração, bem como a oxidação com a associação do permanganato de potássio e cloro realizada após a flotação, resultaram em eficiência de remoção de microcistina extracelular (microcistina livre no meio líquido) da ordem de 95%, atendendo ao padrão de potabilidade com cocentrações de microcistina menores que 1,0 µg/L. A oxidação da água bruta com permanganato de potássio associada à oxidação da água flotada com cloro, apresentou o melhor desempenho de remoção de microcistina extracelular, com eficiência superior a 98%. Em todos os ensaios de oxidação química foi constatada a influência da variação do pH na remoção de microcistina, sendo que o aumento de eficiência foi associado à diminuição dos valores de pH. Foram observados indícios de remoção de trihalometanos pela flotação por ar dissolvido e redução da formação de trihalometanos quando a oxidação química foi feita com a associação do permanganato de potássio e cloro. / The aim of this research was to study the phytoplankton and microcystin removal at different treatment conditions, all based in coagulation, flocculation, dissolved air flotation and filtration, complemented by chemical oxidation applied at different points of the basic treatment sequency. The lab scale experiments was conduted with raw water prepared by a mixture of natural water, collected in Barra Bonita reservoir at São Paulo State, Brazil, and a high concentrated Microcystis culture prepared in laboratory. The microcystin concentration in raw water was kept in a range of 14 to 17 µg/L. Ferric chloride was used as coagulant, and, potassium permanganate and chlorine (sodium hypochlorite) were used as oxidants. The results showed phytoplankton removal efficiency about 99,9% by the sequency of coagulation, flocculation and dissolved air flotation, resulting a great removal of microcystin retained into the whole cells. The chlorine oxidation after filtration, as well as the oxidation with potassium permanganate and chlorine after dissolved air flotation, resulted in a microcystin removal of about 95% and concentrations under the World Health Organization drinking water guideline value of 1,0 µg/L. The raw water potassium permanganate oxidation associated with the chlorine oxidation after flotation, leaded to the best results concerning microcystin removal, with efficiency above 98%. All experimental conditions with chemical oxidation showed a relevant effect of the pH on the microcystin removal, the decrease of pH values contributed to the increase of microcystin removal. It was observed signs of THM´s removal by the dissolved air flotation and reduction of THM´s production when the chemical oxidation took place with the association of potassium permanganate and chlorine.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-03T13:38:20Z No. of bitstreams: 2 Dissertação - Joicy Martins Morais - 2013.pdf: 662106 bytes, checksum: c4e0fdd3441863cf9479d5c5b0b5be2f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-04T09:48:31Z (GMT) No. of bitstreams: 2 Dissertação - Joicy Martins Morais - 2013.pdf: 662106 bytes, checksum: c4e0fdd3441863cf9479d5c5b0b5be2f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-04T09:48:31Z (GMT). No. of bitstreams: 2 Dissertação - Joicy Martins Morais - 2013.pdf: 662106 bytes, checksum: c4e0fdd3441863cf9479d5c5b0b5be2f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-11-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The relationships between organisms and the mechanisms that enable their coexistence are important issues in ecology. Plant removal experiments are useful to elucidate these mechanisms because its cause and effect response. This thesis aims to analyze experiments removal plants. The first paper presents a scientometric review of the literature on plant functional groups removal 1991. We verify aspects such as the number of publications and citations in journals indexed in the Web of Science, which country was made in order to detect bias and geographic gaps, which ecological effects were tested, which functional groups were removed, which removal methods and which environments were made. We found an increase in the number of publications and citations on average during this period, however, was 12 times lower than publications on functional diversity, perhaps due to the difficulty of conducting experiments. The work was mainly carried out in temperate climates where taxonomic knowledge is greater, in addition, there is a prevalence of vegetation that is most commonly removed than trees. Testing interactions, especially competition, was the main reason for removal, perhaps as a matter of historical competition is considered the interaction that influences the co-occurrence of species. The cut at ground was the major method of removing, undisturbing the soil and avoiding undesirable effects of herbicides, and few studies have been made in a greenhouse and in the natural environment at the same time, which could elucidate responses to natural conditions and at the same time responses specific interactions. In the second paper we carried a case study on removal of capim-flecha ( Tristachya leiostachya Ness.), a dominant grass in Emas National Park (ENP), and what the consequences of such removal to the co-occurring grasses. We expected that the absence of capim-flecha allow further growth of grasses, however we found no difference in mean values between treatments indicating that there is no competition influencing the abundance of capim-flecha. The historical context burned in PNE may have influenced this high dominance of capim-flecha. We believe that experiments are useful in testing interactions, especially if they are made in the natural environment and greenhouse at the same time. / As relações entre os organismos e os mecanismos que permitem sua coexistência são importantes questões em ecologia. Experimentos de remoção de plantas são úteis em elucidar esses mecanismos, devido sua capacidade de resposta do tipo causa e efeito. Esta dissertação se propõe a analisar experimentos de remoção de plantas. O primeiro artigo apresenta uma revisão cienciométrica das publicações sobre remoção de grupos funcionais de plantas, desde 1991. Verificamos aspectos como o número de publicações e citações em periódicos indexados no Web of Science, em qual país foi feito, visando detectar vieses e lacunas geográficas, quais efeitos ecológicos testados, quais grupos funcionais removidos, quais os métodos de remoção e em quais ambientes foram feitos. Encontramos um crescimento no número de publicações bem como na média de citações nesse período, contudo foi 12 vezes menor do que publicações sobre diversidade funcional, talvez devido à dificuldade de realizar experimentos. Os trabalhos foram realizados principalmente em climas temperados onde o conhecimento taxonômico é maior, além disso, há um predomínio de vegetação rasteira que é mais comumente removida do que árvores. Testar interações, principalmente competição, foi o principal motivo de remoção, talvez por uma questão histórica de competição ser considerada a interação que mais influencia a co-ocorrência de espécies. O corte rente ao solo foi o principal método de remoção, evitando revolver o solo e efeitos indesejáveis de herbicidas, e poucos trabalhos foram feitos em casa de vegetação e ambiente natural ao mesmo tempo, o que poderia elucidar respostas à condições naturais e ao mesmo tempo respostas específicas de interações. No segundo capítulo fizemos um estudo de caso sobre remoção de capim-flecha (Tristachya leiostachya Ness.), uma gramínea dominante no Parque Nacional das Emas (PNE), e quais as consequências dessa remoção para as gramíneas co-ocorrentes. Esperávamos que a ausência do capim-flecha permitiria um maior crescimento das gramíneas, contudo não encontramos diferença nos valores das médias entre os tratamentos o que indica que não há competição influenciando a abundância do capim-flecha. O contexto histórico queimadas no PNE pode ter influenciado essa alta dominância do capim-flecha. Consideramos que experimentos são úteis em testar interações, sobretudo se forem feitos em ambiente natural e casa de vegetação ao mesmo tempo.

Strategies to improve stem yield and juice quality in sweet sorghum were investigated in this study. Seed quality of sixty five accessions (landraces) from Botswana was investigated. Standard germination tests revealed that only 66% of the accessions had germination percentages in excess of 85%. The Accelerated Ageing test showed that only 50%of the 26 accessions had germination percentages above 80%. The results indicated that Botswana sweet sorghum seed quality is generally poor. Seed development and maturity observations demonstrated that maximum seed quality occurred 14 to 17 days after mass maturity (physiological maturity) and this coincided with maximum seed germination. These results suggest that harvesting sweet sorghum seed prior to mass maturity can lower seed quality. Farmers should, therefore be advised to select plants intended for seed harvesting and allow them to mature properly before the seeds are harvested. Differences in seed colour, shape and compactness of the inflorescences were observed amongst the 65 landraces collected from farmers in Botswana. Ten landraces were characterised and from the results it was evident that there was a range of genetic diversity which can be utilized in the improvement of the crop. Large panicles were characteristic of most sweet sorghum landraces, the effect of tiller, panicle and floret removal on juice quality was consequently studied. Removal of panicles and florets significantly improved juice quality whilst removal of tillers did not. Selection and breeding of genotypes with small panicles and male sterile varieties may improve juice quality and should be investigated. Effect of planting date, spacing and nitrogen were investigated. Early planting (October) resulted in increased stem yields but reduced juice quality. A 30 cm intra-row spacing resulted in high stem yields per plant and good juice quality. Nitrogen fertilisation increased stem yield and improved juice quality. On the bases of the results obtained from this study, early planting (October), application of 60 kg N ha-¹, and 30 cm intra-row spacing could be recommended for sweet sorghum production in pure stands. In pure stands yields of more than 37 000 stems (per hectare) of good quality can be attained. These could be sold at an estimated price of P2.00 (R2.25) per stem indicating the potential of sweet sorghum as a cash crop. However, its economic viability depends on the price elasticity in the supply - demand function. / Dissertation (PHD)--University of Pretoria, 2003. / Plant Production and Soil Science / unrestricted

[pt] Este trabalho investiga a eficiência do Processo Oxidativo Avançado eletro-Fenton (EF) no tratamento de efluentes da indústria de celulose e papel previamente tratados por processo biológico. Utilizou-se planejamento fatorial em três variáveis e dois níveis, variando-se pH inicial (4 e 6), dosagem de H2O2:COD (1:1 e 2:1mol/mol) e densidade de corrente (j) (4 e 10mA/cm2). Experimentos foram realizados em reator de 1L com eletrodos de aço SAE1010, em regime de batelada, com tempo de reação de 60min. Avaliou-se também o processo Fenton convencional e realizou-se ensaios de controle com oxidação por H2O2, Eletrocoagulação e Fenton Zero, em 20min. Quanto ao EF, observou-se que um tempo de 40min foi suficiente para estabilização da remoção de cor e compostos lignínicos e 20min para remoção de carbono orgânico dissolvido (COD) nos processos com maior j e 40min, naqueles com menor j. A melhor configuração do EF foi com pH inicial 4, relação H2O2:COD 1:1mol/mol e menor j (4mA/cm2), alcançando-se remoção de 82 porcento de COD, 99 porcento de compostos lignínicos e 99 porcento de cor verdadeira, com consumo energético de 1.0 kWh/m3. Comparando-se os processos avaliados, todos no ponto central do plano fatorial, observou-se maior eficiência do EF na remoção de cor e compostos lignínicos e menor eficiência na remoção de COD, em relação ao processo Fenton convencional, contudo, com maior eficiência em sua melhor condição operacional. Conclui-se que o EF se mostra eficiente no polimento deste efluente para remoção da matéria orgânica e cor verdadeira remanescentes do processo biológico e que o parâmetro de maior influência neste processo é a densidade de corrente. / [en] This study investigates the efficiency of the Advanced Oxidation Process electro-Fenton (EF) in the wastewater treatment from pulp and paper industry, previously treated biologically. A factorial design of three factors and two levels was used, varying initial pH (4 and 6), H2O2:COD ratio (1:1 and 2:1mole/mole) and current density (j) (4 and 10mA/cm2). Experiments were made in a 1L reactor in batch mode with SAE 1010 steel electrodes, in 60min reaction time. The conventional Fenton process was also evaluated and control tests were carried out with direct oxidation by H2O2, Electrocoagulation and Zero-valent Fenton, with 20min. As for the EF process, it was observed that a 40min reaction time was enough to stabilize the colour and removal of the lignin compounds, and 20 minutes to remove dissolved organic carbon (COD) in the processes with higher j and 40min, in those with lower j. The best configuration for the EF process was initial pH 4, H2O2:COD ratio 1:1mole/mole and lower j (4mA/cm2), leading to 82 percent COD, 99 percent lignin compounds and 99 percent colour removal, with energy consumption of 1.0kWh/m3. Comparing the evaluated processes, all at the central point of the factorial design matrix, it was observed greater efficiency of the EF in the colour and lignin compounds removal and lower efficiency in COD removal in relation to the conventional Fenton, nevertheless, with greater efficiency in its best overall condition. It was concluded that the EF-process is efficient as a polishing step of this wastewater treatment to remove the remaining organic compounds and true color from the biological process and that the parameter of greatest influence in the EF-process is the current density.

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

Made available in DSpace on 2017-07-21T18:53:21Z (GMT). No. of bitstreams: 1 Priscila Arcoverde Wosiack.pdf: 2005192 bytes, checksum: 49fa05e9e5f72b1ae4d6f70637a69779 (MD5) Previous issue date: 2014-06-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The treatment of wastewater generated in the pet food industries, characterized by the high organic carbon and nitrogen content, becomes necessary to meet the standards required by the legislation and minimize environmental impacts on water bodies. Biological treatment is an effective way to treat potentially polluting wastes from agroindustries processes. However, conventional systems for treating industrial wastewater do not allow the simultaneous removal of organic carbon and nutrients. Thus, the present study aimed to evaluate the performance of a structured bed reactor with continuous flow, for the simultaneous removal of carbon organic, expressed as Chemical Oxygen Demand (COD), and nitrogen from wastewater of a pet food industry, under conditions of intermittent aeration. The system was composed by a structured bed reactor under 30oC of temperature, and recirculation ratio of 5 times the flow. The reactor was initially operated in differents Hydraulic Retention Times (HRT) of seven, five, three and one day under continuous aeration. In such conditions were verified removal of COD above 80% and Total Nitrogen (TN) above 60%. The best results were obtained with HRT of three days (91.8% of COD removal and 93.3 % of TN). The response surface methodology was used to evaluate the effect of aeration and load of TKN (Total Kjeldahl Nitrogen) in the removal of COD and TN, with HRT fixed in 1 day. It was observed that the parameter aeration was the most important for the results. The removal of COD reached levels of 85% when the reactor was aerated on 100% of the time. Aeration also was positive for nitrification and negative for denitrification. The best responses obtained for the removal of COD and TN, nitrification and denitrification were 80.03%, 88.16%, 99.13% and 88.92%, respectively, and were obtained with 158.2 minutes of aeration in a cycle of 180 minutes, and 255.1 mg.L-1 of the TKN affluent. In view these results, it was concluded that this new system was effective in simultaneous removal of nitrogen and carbon organic matter. / O tratamento das águas residuárias geradas nas indústrias de ração animal, caracterizadas por elevada carga orgânica e conteúdo nitrogenado, torna-se absolutamente necessário para atender aos padrões exigidos pela legislação e minimizar impactos ambientais em corpos de água. O tratamento biológico é uma maneira eficaz de se tratar resíduos potencialmente poluidores originados de processos agroalimentares. Porém, sistemas convencionais de tratamento de águas residuárias industriais, não possibilitam a remoção simultânea de matéria orgânica e nutrientes. Assim, o presente trabalho teve como objetivo avaliar o desempenho de um reator de leito estruturado e fluxo contínuo, na remoção simultânea da matéria orgânica carbonácea, expressa em Demanda Química de Oxigênio (DQO), e nitrogenada, das águas residuárias de uma indústria de ração animal, sob condições de aeração intermitente. O sistema foi composto por um reator de leito estruturado mantido à temperatura de 30oC e taxa de recirculação de 5 vezes a vazão. O reator foi inicialmente operado em diferentes Tempos de Detenção Hidráulica (TDH), de sete, cinco, três e um dia, sob aeração contínua. Nestas condições foram verificadas remoções de DQO acima de 80% e de Nitrogênio Total (NT) acima de 60%. Os melhores resultados foram obtidos com TDH de três dias (91,8% de remoção de DQO e 93,3% de NT). A metodologia de superfície de resposta foi utilizada para avaliar o efeito da aeração e da carga de NTK (Nitrogênio Total Kjeldahl) na remoção de DQO e NT, com TDH fixo em um dia. Foi verificado que o parâmetro aeração foi o que mais influenciou os resultados. A remoção de DQO chegou a 85% quando o reator foi aerado em 100% do tempo. A aeração também apresentou efeito positivo para a nitrificação, mas negativo para a desnitrificação. As melhores respostas para remoção de DQO, NT, nitrificação e desnitrificação, de 80,03%, 88,16% 99,13% e 88,92%, respectivamente, foram obtidas com o reator operando com 158,2 minutos de aeração a cada ciclo de 180 minutos e 255,1 mg.L-1 de NTK afluente. Diante destes resultados, conclui-se que este novo sistema foi eficiente na remoção simultânea de matéria orgânica e nitrogenada.

Groundwater arsenic contamination is currently a global problem, and also a concern at numerous former industrial sites, agricultural sites, landfill sites and mining operations in the U.S. This dissertation aims to develop improved strategies of remediating these arsenic contaminated aquifers. It focuses on two distinct approaches of remediation: (1) mobilizing arsenic from contaminated aquifer sediments to decrease the quantity of arsenic at the source of contamination; and (2) immobilizing arsenic in situ, to decrease the mobility and bioavailability of this arsenic. Optimal remediation may well involve combinations of these two approaches. Arsenic mobilization using oxalic acid is effective because oxalic acid dissolves arsenic host minerals and competes for sorption sites on those minerals. In this dissertation, oxalic acid treatment was tested using sediments with contrasting iron mineralogies and arsenic contents from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized arsenic from both sites and the residual sediment arsenic was less vulnerable to microbial reduction than before the treatment. Oxalic acid thus could improve the efficiency of widely used pump-and-treat remediation. Oxalic acid did not remove all of the reactive iron(III) minerals in Vineland sediment samples, and thus released significant quantities of arsenic into solution under reducing conditions than the Dover samples. Therefore, the efficacy of pump-and-treat must consider iron mineralogy when evaluating its overall potential for remediating groundwater arsenic. Arsenic immobilization occurs by changing the chemical state, or speciation, of arsenic and other elements in the system. Arsenic is often assumed to be immobile in sulfidic environments. In this dissertation, sulfate reduction was stimulated in sediments from the Vineland Superfund site and the Coeur d'Alene mining district. Sulfate reduction in the Coeur d'Alene sediments was more effective at removing arsenic from solution than the Vineland sediments. The Vineland sediments initially contained abundant reactive ferrihydrite, and underwent extensive sulfur cycling during incubation. As a result, arsenic in the Vineland sediments could not be effectively converted to immobile arsenic-bearing sulfides, but instead a part of the arsenic was probably converted to soluble thioarsenates. Therefore, coupling between the iron and sulfur redox cycles must be fully understood for arsenic immobilization by sulfate reduction to be successful. Arsenic can also be immobilized by retention on magnetite (Fe3O4). Magnetite is stable under a wide range of aquifer conditions including both oxic and iron(III)-reducing environments. In this dissertation, a series of experiments were performed with sediments from the Dover and Vineland Superfund sites, to examine the potential of magnetite for use in arsenic immobilization. Our data suggest that the formation of magnetite can be achieved by the microbial oxidation of ferrous iron with nitrate. Magnetite can incorporate arsenic into its structure during formation, forming a stable arsenic sink. Magnetite, once formed, can also immobilize arsenic by surface adsorption, and thus serve as a reactive filter when contaminated groundwater migrates through the treatment zone. Reactive transport modeling is used for investigating the magnetite based arsenic immobilization strategy and for scaling laboratory results to field environments. Such modeling suggests that the ratio between iron(II) and nitrate in the injectant regulates the formations of magnetite and ferrihydrite, and thus regulates the long-term evolution of the effectiveness of the strategy. The results from field-scale models favor scenarios that rely on the chromatographic mixing of iron(II) and nitrate after injection. The studies in this dissertation demonstrate that the environmental fate of arsenic depends on the biogeochemical cycling of arsenic, iron, and to a lesser extent, sulfur. The development of effective groundwater arsenic remediation strategies depends on a good understanding of each of the involved processes, and their combinations.