published_or_final_version / abstract / Civil Engineering / Master / Master of Philosophy

Thesis (M. Phil.)--University of Hong Kong, 2008. / Also available in print.

Large polycyclic aromatic hydrocarbons with molecular mass exceeding 278 Da are rarely object of study, in spite of the fact that some compounds from this group are proved carcinogens. These compounds belong to the group of persistent organic compounds and they are considered as dangerous environmental contaminants. Diploma thesis is focused on the evaluation of the occurence of large PAHs in technological and waste waters produced in black pitch processing in the DEZA Valašské Meziříčí factory. The method of their analysis based on reversed-phase liquid chromatography with non-aqueous gradient; UV-VIS and fluorescence detection will be used. This method will enable the study of changes of large PAHs distribution at various stages of waste water treatment process.

Many drinking water treatment facilities face problems with algal organic matter (AOM) due to eutrophication of the environment and frequent occurrence of algal blooms. AOM can cause deterioration of water organoleptic properties, but the main threat is the potential for acting as a precursor of toxic disinfection by-products (DBPs). The presented master thesis deals with the possibility of using electrocoagulation (EC) - an innovative electrochemical method - to remove cellular organic matter (COM) produced by cyanobacteria Microcystis aeruginosa from drinking water. EC is similar to widely used chemical coagulation, the difference is that during EC the coagulant is produced by electrochemical dissolution of an iron or an aluminum electrode. Synthetic water with COM concentration of 5.5 and 8.5 mg/L of TOC was used for the experiments. The target value of conductivity (4.5 mS/cm) was reached by addition of NaCl. pH of the solution was adjusted by HCl and NaOH. During some of the experiments, NaHCO3 was added to increase the ANC4.5. The experiments were conducted in a batch mode with a stainless-steel cathode and an aluminum or an iron anode. The coagulant dosage was regulated by applied electric current passing through the electrodes. Flocs were separated by sedimentation and centrifugation. COM...

Synthetic musk compounds were first prepared artificially in the late 19th century. They have been used to perfume cosmetics, detergents and personal care products. The attention of many researchers has been focused on it recently, due to its high penetration into the nature which is a logical consequence of its great use. The main goal of this thesis is to determine the effect of the ultrafiltration on the concentration reduction of substances mentioned above in the industrial waste waters produced by the cosmetic company. Analytes from the sample were extracted using solid phase microextraction (SPME) and on gas chromatography analysis with mass spectroscopy (GC / MS) has been performed. The whole method was optimized and evaluated. Determination of the average efficiency of the ultrafiltration was made based on data obtained before and after ultrafiltration. Such efficiency determines the suitability of use of this method for removal of synthetic musk compounds from waste waters.

The PhD thesis deals with determination of sulfonamides and tetracyclines in waste waters. Sulphonamides and tetracyclines are widely used in human and veterinary medicine. They are biologically active compounds and block biological processes in waste water treatment plants. These substances can influence microorganisms in the environment. Sulphonamides and tetracyclines induce resistance in low concentrations. These substances penetrate into the environment from industrial production, use in households, hospitals, veterinary clinics and fish farms. Tetracyclines and sulphonamides were determined in waste water from waste water treatment plants in Brno. Optimalization of extraction of these compounds was performed by solid phase extraction. Sulphonamides and tetracyclines were determined by liquid chromatography coupled with diode array detector or coupled with mass spectrometry. Optimalized method was used for determination tetracyclines and sulphonamides in waste water from waste water treatment plants in Brno in years 2007 – 2010.

Orientador: Elisa Helena Giglio Ponsano / Resumo: No processo de produção do surimi, grande quantidade de água é utilizada para as operações de lavagens, resultando na geração de grande volume de águas residuárias ricas em matéria orgânica que causam problemas ambientais quando descartadas inadequadamente. As proteínas presentes nestas águas podem ser recuperadas, reduzindo o impacto ambiental e gerando um ingrediente com aplicação na indústria de alimentos. O objetivo geral deste estudo foi recuperar proteínas das águas de lavagem de preparo do surimi utilizando a tecnologia de filtração por membranas e utiliza-las na elaboração de fishburguer. As águas de lavagem resultantes da produção do surimi de tilápia foram reunidas e filtradas em membrana de ultrafiltração (UF) de 30 kDa. As determinações de pH, sólidos totais (ST) e fixos (SF), proteínas totais, óleos e graxas e a análise eletroforética foram realizadas nas águas obtidas nas lavagens do surimi (original) e após a UF (concentrado e permeado) e a demanda química de oxigênio (DQO) foi determinada nas águas originais e no permeado da UF. O concentrado desidratado em spray dryer foi analisado quanto ao perfil de aminoácidos e teor de carotenóides. As proteínas recuperadas no concentrado desidratado foram adicionadas nas proporções de 0, 5 e 10% aos fishburgers de surimi e os produtos finais foram avaliados quanto à composição proximal, rendimento na cocção, análise sensorial e índice de aceitabilidade (IA). Os dados físicos e químicos das águas originais, do concentrado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the production process of surimi, a large amount of water is used for washing operations, generation waste water rich in organic matter that causes environmental problems when they are improperly disposed. Proteins present in these waters can be recovered, reducing their environmental impact and generating an ingredient with application in the food industry. The general objective of this study was to recover proteins from surimi elaboration wash waters, using membrane filtration technology, and use them in fishburger elaboration. Wash waters resulting from tilapia surimi production were pooled and filtered on ultrafiltration membrane (UF, 30 kDa). Determination of pH, total (ST) and fixed solids (SF), total proteins, lipids and electrophoretic analysis were performed in the waters obtained from wash process of surimi (original) and after UF (concentrated and permeated). Oxygen chemistry (COD) was determined in the original waters an in the UF permeate. Spray-dried dehydrated concentrate was analyzed for amino acid profile and carotenoid content. Proteins recovered in the dehydrated concentrate were added in the proportion of 0, 5 and 10% to surimi fishburgers, and final products were evaluated for proximal composition, cooking yield, sensory analysis and acceptability index (IA). Physical and chemical data of the original concentrate and permeate waters and the proximal composition of fishburgers were subjected to an analysis of variance (ANOVA) and means were compared by ... (Complete abstract click electronic access below) / Doutor

Surfactants belong to surface-active compounds that have ability to restrain the surface tension; this ability is exploited to eliminate impurities. This study is focused on determination of surfactants in waste water to which these compounds can be transported from various cleaning and washing articles. In theoretical part are listed basic classifications of surfactants, their properties and requests of Czech legislative for their content in waste water. Furthermore here are described chosen analytical procedures for determination of anion-active, cation-active and non-ionic surfactants in waste water. The conclusion of the work is evaluation of measured results of surfactants concentration in inflow and outflow of waste water from waste-treatment plant in University of Veterinary and Pharmaceutical Sciences Brno and waste water from neutralizating station in FCH BUT. To determination of anionic surfactants were used two methods, arbitration method with usage of methylene blue and mobile analytics method which is based on chemical reaction between target compound and chemical agent. This reaction leads to formation of coloured compound able to spectrofotometric determination.

<p> Government programs now underway in Ontario aim at removing phosphates from waste-waters at sewage treatment plants. At present, removal of phosphates is commonly accomplished by chemical precipitation with lime, alum, or iron. Lanthanum, a rare earth element, has been found to be an effective precipitant of phosphates. If lanthanum precipitate can be collected, and the lanthanum then regenerated so that it could be recycled for further phosphate precipitation, a very advantageous alternative to the above schemes would result.</p> <p> In this study, phosphates were precipitated from both distilled water and secondary effluent using lanthanum. For the two cases, a regeneration scheme for lanthanum was examined. The basic regeneration reactions were carried out to evaluate the kinetics and equilibria for different ratios of reactants and different reaction temperatures. Techniques for phase separation of reacted reagents were studied. Process design calculations were carried out to obtain order of magnitude figures for amounts and costs of chemicals required, amounts of sludge produced, and reactor sizes.</p> / Thesis / Master of Engineering (MEngr)

Nowadays are foam concentrates used as the primary extinguishing agent for flammable liquid fires (especially hydrocarbons), means of transports fires, the release of chemical substances in environmental accidents, and their importance is still growing with the industrial development. All units of fire protection have foam concentrates in their equipment, so it is important that firefighters to have some necessary knowledge about their characteristics and to be able to use them effectively and safely for the environment. The basic component of foaming concentrates are surfactants. This diploma thesis analyzes foam samples which are commonly used, by methods for analysis of drinking, surface and wastewater and determines cationic, anionic and nonionic surfactants.