Thesis (M.S.)--University of Wisconsin-Madison, 1982. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 208-225).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xv, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-84).

Thesis (M.S.)--University of Wisconsin, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 126-129).

For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.

Olive mill wastewater is produced in large quantities during the production of olive oil and olive production effluents are produced during the processing of olives. This project was planned to find a use for constituents found in olive production wastewater. The task was carried out by first characterizing the olive effluents, then screening microorganisms for growth in the effluents and reduction of the pollutant properties of the effluents. An investigation into the biotransformation of aromatic compounds present in the effluents into useful chemicals, was carried out. The olive production effluents were collected from different stages in the process for treating olive wastewater, viz, a fermentation tank (FB), the surface of a digester (LV) and an evaporation pond (SO). The three effluents were characterized by investigating their phenolic composition. Protocatechuic acid, vanillic acid, syringic acid, hydroxyphenyl acetic acid, coumaric acid and ferulic acid were identified in an olive effluent, FB, using thin layer chromatography (TLC) and High perfomance liquid chromatography (HPLC). Hydroxyphenyl acetic acid constitutes almost 60% of the organics in olive effluent FB. Five bacteria, namely RU-LV1; RU-FBI and RU-FB2; RU-SOI and RU-S02, were isolated from the olive effluents LV, FB and SO respectively. These isolates were found to be halotolerant and were able to grow over a broad temperature and pH range, with the maximum temperature and pH for growth being 28°C and pH 7 respectively. A range of microorganisms were evaluated for their ability to grow and reduce the total phenolic content of the olive effluents. Among these Neurospora crassa showed the highest potential for the biological reduction of total phenolics in olive effluents. Approximately 70% of the total phenolic content was removed by N. crassa. Trametes verscilor, Pseudomonas putida strains, RU-KMI and RU-KM3s, and the bacteria isolated from olive effluents could also degrade the total phenolic content of olive effluents, but to a lesser extent. The ability of the five bacterial isolates to grow and degrade aromatic compounds was assessed by growing them in medium with standard aromatic compounds. RU-L V1 degraded 96%, 100%, 73% and 100% of caffeic acid, protocatechuic acid, p-coumaric acid and vanillic acid respectively. The other isolates degraded caffeic acid and protocatechuic acid, but their ability to degraded p-coumaric acid and vanillic acid was found to be lesser than the ability of RU-LV1 to degrade the same aromatic compounds. Whole cells of RU-LV1 degraded vanillic acid but no metabolic products were observed on HPLC analysis. Resting cells, French pressed extract, cell free extracts and cell debris from RU-LV1 cells induced with vanillic acid degraded vanillic acid, ferulic acid and vanillin at rates higher than those obtained from non-induced cultures. No products were observed during the degradation of vanillic acid. Ferulic acid was converted into vanillic acid by French pressed extract, cell free extract and cell debris of RU-LV1. The maximum yield of vanillic acid as a product (0 .23 mM, 50 %yield) was obtained when cell free extracts of RU-LVI, grown in glucose and induced by vanillic acid, were used for the degradation of 0.4 mM ferulic acid. Vanillin was rapidly converted into vanillic acid by resting cells, cell free extracts and French pressed extract of RU-LVI. Using molecular techniques, the similarity ranking of the RU-LVI 16S rRNA gene and its clone showed a high similarity to Corynebacterium glutamicum and Corynebacterium acedopltilum. The rapid degradation of vanillin to vanillic acid suggests that extracts from RU-LV1 degrade ferulic acid into vanillin which is immediately oxidized to vanillic acid. Vanillic acid is also considered as a high value chemical. This project has a potential of producing useful chemicals from cheap substrates that can be found in olive effluents. / KMBT_363

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 91-95). Also available via the Internet.

The growing concern for water quality enhancement of our surface waters has led to changes in detention facility design. Providing a filter media for the effluent water to travel through before discharge into the environment has become an area of interest. Thus, detention facilities may be used for both water quality and quantity control. Different soil medias were studied for the potential of pollutant removal and infiltration rates usable in design work. Both laboratory and field experimentation were performed. A computer program was also developed to model stormwater movement through a swale detention system. This research was performed to examine filter media and to indicate the advisability of designing a combination of detention ponds and berms.

The removal of colour from effluent after dyeing of cellulosic fibres is a major problem due to the difficulty in treating such effluents by conventional treatment methods. Cellulosic fibres of a specific shade (colour) are produced by reacting the fibres with a mixture of reactive dyestuffs, salt and auxiliary chemicals. Reactive dye exhaustion to the fibre is about 80% i.e. 20% remains in the effluent; this is hydrolysed dye which cannot be reused for dyeing. The exhausted reactive dye bath together with first rinse represents 6 to 30 L effluent/kg of fabric and most of the colour and salt. The total water consumption for reactive dyeing ranges from 25 to 100 L effluent/kg fabric while the water consumption from total textile finishing ranges from 30 to 150 L effluent/kg fabric. Thus the concentration of the dye and salts are 5 times more concentrated when obtained at source. The use of activated carbon adsorption for the removal of colour from exhausted dyebath for the re-use of water, salt and energy has been studied. Four different commercial reactive dye chemistries and associated auxiliaries were tested and commercial activated carbon was used as an adsorbent. Different temperatures (20°C to 100°C), pH values (acidic, neutral, basic) and salt concentrations (50 g/L to 100 g/L) were evaluated and the high adsorption results were achieved when using high temperature, low pH (acidic) and high salt concentrations. The Freundlich adsorption parameters were obtained for activated carbon adsorption capacity and adsorption bond strength between reactive dyes and activated carbon. The overall removal of the reactive dye shades was 36% to 53% (based on colour in the effluent), salt recovery was about 94% to 97%, the water recovery ranged from 14% to 25% and energy savings of 17% to 32% could be achieved. Column adsorption test were performed at different temperatures and flowrates. The saturated activated carbon was regenerated and repeatedly used by elution with 1.0 M NaOH. The regenerated carbon was found to be effective up to 3 cycles of operations. A column system for treatment of reactive dyes using activated carbon was designed. The outcome of this study showed that treatment of reactive dyebath with activated carbon adsorption technique can allow re-use of water, salt and energy, thus enabling environmental improvements with a savings in salt, energy, water and treatment costs. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2007.

Thesis (PhD)--University of South Australia, 2001.

Thesis (M.S. - Soil, Water and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves [64]-69).