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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Using Constructed Wetland for Industrial Wastewater Treatment

Lay, En-Hwa 18 August 2003 (has links)
Abstract Constructed wetlands can be treated as a imulated natural treatment system,which use solar adiation as the source of energy. By analogy with some removalmechanisms in natural wetlands, constructed wetlands are able to transform and remove pollutants from the wastewater. Other features provided by the constructed wetland include wildlife support, hydrologic odification, erosion protection, and open space and aesthetics. It has been applied for domestic wastewater purification for decades. The goal of this study was to evaluate the ffectiveness of using constructed wetlands on industrial wastewater treatment. In this study, grit chamber and furnace waste from steel-making were used as the media for plant growth. Two -tank (dimension for each tank: 4L ¡Ñ1W ¡Ñ1H) system was designed and constructed to simulate the constructed wetland. Reed and cattail were planted in the first and second tanks, respectively. In the system, media in the first and second tanks were filled to a height of 0.4 m (furnace waste from steel-making) and 0.1 m (waste grit), respectively. The depth of water was maintained at 0.3 m. The hydraulic retention time was approximately 5 days. The following parameters were analyzed during the operational period: nutrients, chemical oxygen demand (COD), suspended solids (SS), and biochemical oxygen demand (BOD). The calculated removal rates (g/m2/day) in the first tank were¡GCOD 5.92¡Ó0.64¡BBOD 3.48¡Ó0.95¡BSS (suspended solids) 3.42¡Ó1.44¡BTKN (total kjedal nitrogen, TKN) 0.94¡Ó0.26¡BTP (total phosphorus) 1.33¡Ó0.2¡CThe removal rates (g/ m2/day) in the second tank were: COD 5.17¡Ó0.62¡BBOD 3.21¡Ó0.92¡B SS 2.92¡Ó1.29¡BTKN 0.59¡Ó0.21¡BTP 0.66¡Ó0.15. Results from this study indicate that the media and plants in both tanks created a biofiltration system for microbial growth and pollutant removal. Sorption and biodegradation were the two major pollutant removal mechanisms in the system. During the operational period, the average removal efficiencies (%) in the first tank were: COD 55~62, BOD 73~90, SS 66~84, TKN 36~66, TP 28~39. The average removal efficiencies (%) in the first tank were: COD 49~54, BOD 73~83, SS 45~69,TKN 15~43, TP 9~24.
2

Effects of Heat Transfer Fluid from District Heating Networks on Activated Sludge : A respirometric analysis using a dilution series to assess disruption of biological treatment processes in wastewater treatment facilities

Bergseije, Victor January 2014 (has links)
District heating has a long standing tradition in Sweden and today it is the most common way of producing and transporting heat. A District heating system (DH system) is divided into three parts: a production facility, distribution network (DH network) and one more heat stations. The heat produced in the facilities is distributed to the customers via a heat transfer medium, usually water (DH water), in piping networks that make up the DH network. The heat is transferred to the customers via the heat exchanger at which point they can use it as heated tap water or for heating purposes. The DH networks are often constructed in steel as it is cheap and a relatively resistant material. However it has the disadvantages of corrosion and expansions when it is exposed high temperatures which lead to damages in the DH network resulting in loss of the DH water, this is an unavoidable occurrence in any DH network. This results in addition of pollutants by leakages into the DH network or with the water that is used to compensate for the losses. The pollutants cause further corrosion, leading to metal contamination, and more damages on the DH network meaning there is a continuous degradation. Therefore various treatments are used to clean and ascertain an acceptable chemical environment in the DH systems. These treatments are effective but not at a level which is required so many chemicals are used to enhance the treatment of the water. Some of these are known to be toxic to humans and water ecosystems. As leakages are abundant and often end up in the WWTPs of the concerned municipality, which often have troubles with disturbances of the biological treatment, it was decided that an assessment of the toxic effects that DH water pose on activated sludge was to be investigated. This was done by testing water from two DH networks, Växjö and Kalmar, on the same activated sludge obtained from Tegelviken WWTP in Kalmar. A respirometric bioassay approach established by the Organization for Economic Co-operation and Development (OECD), OECD standard 209; OECD Guidelines for the Testing of Chemicals was used with changes made to exposure and measuring time as this decrease the risk of misinterpretation of the results. A dilution series using different concentrations (6.25%, 25% and 100%) of DH water was tested and compered to a blank control samples containing only activated sludge. Assessment of toxicity on total oxidation, oxidation carbon and oxidation of nitrogen was made. To get some idea of what might cause toxic effect samples of the waters was sent to outside laboratories for analyses of metals. The result from the bioassay and metal analysis was used to formulate risk factors associated with a DH water spill and exposure to WWTPs. It was found that both DH waters have a significant inhibition on nitrification in WWTPs. The DH water from Kalmar exhibited similar toxicity dynamics, roughly 20% inhibition, despite large differences in concentration. The DH water from Växjö showed a negative correlation between an increase in concentration of DH water and toxicity, 74% for the lowest concentration and 11% for the highest. The metal analysis concluded that there was no abundance of metal contamination which led to the inference that toxicity is probably caused by the chemicals used for treatment. This poses a great risk for the Baltic Ocean as many WWTPs release their treated water directly into water courses with a short detention time before reaching the sea.
3

Ruopiškio ežero (Rokiškio raj.) asimiliacinių galimybių tyrimai / Assimilation capacity research of Ruopiskis lake (Rokiskis area)

Bacionaitė, Miglė 20 June 2012 (has links)
Magistro darbe nagrinėjama išleidžiamų nuotekų į ežerą koncentracija, asimiliacija. Darbo objektas – Ruopiškio (Alsetos) ežeras. Darbo metodai – pH, BDS7, ištirpusio deguonies, amonio azoto ir suspenduotų medžiagų dalelių koncentracijų skirtumo įtekančiame ir ištekančiame nustatymas ir gautų duomenų analizė. Darbo rezultatai. Tiriant išleidžiamų gamybinių nuotėkų į Ruopiškio (Alsetos) ežerą, koncentracijų (skirtumas) tarp vandens, kuris išteka iš išleistuvo ir vandens, kuris išteka iš ežero, nustatyta, kad asimiliacija yra neigiama, kadangi ištekančiame vandenyje koncentracijos didesnės nei įtekėjo. Vandens rūgštingumo (pH) koncentracija ištekančiame iš išleistuvo vandenyje mažesnė negu koncentracija ežero ištakoje. Biocheminio deguonies sunaudojimo (BDS7) koncentracijų kaita ežere yra labai didelė. Ištirpusio deguonies įtekančiame į ežerą vandenyje, koncentracija yra didesnė, nei ištekančiame iš išleistuvo, tačiau ištekančiame iš ežero jau sumažėjusi. Amonio azoto koncentracija ežere yra didesnė šaltuoju metu sezonu nei šiltuoju. Suspenduotų medžiagų dalelių nusėdimo koncentracijų kaita labai skirtinga, tai priklauso nuo veiksnių, kurie būdingi sezono metu (temperatūra, vegetacija, vėjas, kuris įtakoja bangavimą be sroves). Vandeniui pratekant pro ežerą, statistikai reikšmingų skirtumų visais tiriamų rodiklių atvejais nėra (p>0,05), daroma išvada, kad tirtų medžiagų asimiliacija nereikšminga ir ežeras papildomo apvalymo neatlieka. / Discharges of wastewater concentration and assimilation was investigated in the work of master science. Object of the work – Ruopiskis lake (Alseta). Method of the work – pH BOD7, dissolved oxygen, ammonia nitrogen and suspended particulate matter concentracions in the inflowing and out flowing difference identification and analysis of the data. The results of the work. Study of industrial waste water discharged into Ruopiskis (Alseta) lake levels change between the water flowing out of¬ the bleeder and the water that flows from the lake showed that assimilation is negative, since leaving the water levels higher than flow in. Water acidity (pH) concentration in water leaving the bleeder less than concentration flowing from the lake. Biochemical oxygen demand (BOD7) concentrations variation is very high. Ammonium nitrogen concentration in the lake in the cold season is more higher than warm season. Dissolved oxygen in water flowing into the lake the concentration is higher than leaving the bleeder, but leaving the lake has a lower. Deposition of suspended particulate matter concentrations variation very differently, is depending on factors that are typical of the s¬eason (temperature, vegetation, wind, which affects waves and streams). Water flows through the lake, statistically is insignificant in all cases (p>0,05), so there is no assimilation, concluded that the investigated materials assimiliation is insignificant and the lake additional purification does not perform.
4

Investigation of causes of foaming in industrial waste water treatment and effects of substances in industrial waste water treatment

Maleka, Mamohau Julia 06 1900 (has links)
M-Tech: Chemistry (Vaal University of Technology) / ABSTRACT The research was aimed to study the causes of excessive foaming in a waste water treatment plant. Although the activated sludge process has been adopted to treat this industrial waste water , lots of problems were experienced by the inhibitory effects of toxic compounds that are found in industrial effluents and the foaming stability that was very high. Industrial waste water treatment using sludge processes was found to be more challenging than the normal municipal waste water treatment although the principle is the same; the foaming tendencies were found to be more in industrial waste water. In this study the composition of influents to the waste water treatment plant and operating parameter’s effects on foaming tendencies were examined. The foaming potential in the plant was found to be chemically related due to high contamination of compounds such as phenols, which played a major role in formation of stable foam. It was recommended that there must be pretreatment of the incoming influents to minimize their impact to waste water treatment.
5

Mise au point de méthodes pour l’analyse de substances critiques issues des rejets industriels et de la fabrication des produits de la filière cuir / Analytical developments for the determination of critical substances of the leather field in waste water and leather goods

Rey, Aurélien 24 February 2012 (has links)
Dans le cadre de la protection de l’environnement et du consommateur, CTC effectue des tests enchimie analytique sur de nombreux paramètres en matrices aqueuses, cuir et textile. Les nouvelles substancesmises sur le marché ainsi que les réglementations évoluant sans cesse, le développement de nouvellesméthodes d’analyses est donc nécessaire.Plusieurs méthodes analytiques ont ainsi été développées. Pour l’analyse des rejets d’effluents industriels desinstallations classées et pour l’analyse d’innocuité de produits utilisant le cuir ou le textile (chaussures,maroquinerie, prêt-à-porter…).Les chloroalcanes ont été dosés en chromatographie gazeuse (GC) associée à la spectrométrie de masse (MS)utilisant l’ionisation chimique, à la fois en matrices aqueuses (limite de quantification, LQ, à 0,6 μg/l) et sur lescuirs (LQ à 2 mg/kg).Une analyse des alkylphénols et alkylphénols ethoxylates a été développée pour les matrices aqueuses parGC/MS (LQ à 0,05 μg/l).Plusieurs familles de retardateurs de flammes ont ensuite été étudiées. Les polybromodiphénylethers peuventêtre dosés dans les eaux (LQ<0,05 µl) et le cuir (LQ <= µg/kg), par GC/MS en ionisationchimique.L’hexabromocyclododécane et des organophosphates, par chromatographie liquide et spectrométrie de masseen tandem pour des matrices textiles (LQ à 6 mg/kg). Des hydrocarbures aromatiques polycycliques dans le cuir ont ensuite été analysés par GC/MS-MS (LQ à 250 μg/kg).Enfin, une méthode multirésidus portant sur plusieurs familles de micropolluants organiques a été mise aupoint en GC/MS pour les rejets d’effluents (LQ <0,1 µg/l) / Taking in account the increasing needs and demands in environmental and consumer protection, CTCis always seeking improvement in analytical methods and development of new ones dealing with leather,fabrics and aqueous samples. In this thesis, several new methods were developed to be able to handleanalytical requests dealing with leather and textile materials being parts of shoes, clothes and other leathergoods.A GC/MS method using chemical ionization was developed to detect short polychlorinated alkanes down to aconcentration of 0.6 μg/L in aqueous sample and 2 mg/kg in leather samples. Alkylphenols and theirethoxylates were similarly determined by GC/MS down to 0.05 μg/L.Flame retardants are another large class of chemicals becoming suspicious. Polybromodiphenylethers weredetermined in aqueous samples and leathers. The respective GC/MS highest limits of quantification (LOQ)were0.05 µg/l and 80 μg/kg. Other members of this class are hexabromocyclododecane andorganophosphates. Both were determined by LC/MS-MS with LOQ of about 6 mg/kg.Carcinogenic polyaromatic hydrocarbons were also determined in leather samples using GC/MS-MS down to250 μg/kg.The last improved GC/MS analytical method was handling sewage sludge seeking multi residues of organicpolluants down to the 0.1 µg/l level or below. The analytical performances developed or improved allowedfor an efficient and useful control of the various sample received from the CTC customers and followinginternational quality rules
6

Estudo de degradação fotoquímica para reúso de águas de processo em complexo industrial petroquímico. / Study of photochemical degradation to reuse of process water at petrochemical industry.

Lira, Daniella Cristina Barbosa de 06 December 2006 (has links)
A racionalização dos recursos hídricos tem sido uma das metas das indústrias em vários setores. Tais metas exigem inovações tecnológicas tanto para novos processos produtivos quanto para novas técnicas de tratamento e reutilização de água na cadeia de produção. Os custos elevados de água industrial no Brasil, particularmente nas regiões metropolitanas, têm estimulado as indústrias nacionais a avaliar as possibilidades de reúso. O objetivo deste trabalho é a aplicação do tratamento de águas de processo contendo polipropileno utilizando radiação ultravioleta e peróxido de hidrogênio, isto é, o sistema UV/H2O2, visando adequá-las para reúso no próprio processo, reduzindo a necessidade de captação de água pré-tratada e de descarte de efluente. A primeira parte do estudo consistiu na realização de experimentos em um sistema fotoquímico de batelada, empregando quatro diferentes correntes efluentes de processo, para a avaliação da viabilidade técnico-econômica do tratamento fotoquímico, bem como para a obtenção de dados referentes à cinética das reações fotoquímicas. Com base nas informações obtidas, na segunda parte do estudo foram realizados experimentos em um sistema fotoquímico contínuo, a fim de obter dados para o aumento de escala para aplicação industrial do processo de tratamento contínuo. Os resultados experimentais indicaram a viabilidade técnica de aplicação do sistema UV/H2O2 utilizando fonte de luz artificial para todas as correntes de processo estudadas, tendo sido alcançados níveis de remoção de matéria orgânica acima de 90%. No entanto, sob o ponto de vista econômico, apenas as correntes com baixo teor de carbono orgânico total dissolvido (COT), entre 6 e 12 mgC L-1, mostraram-se adequadas ao reúso, após o tratamento. / Rationalization of water use has been one of the goals in many industrial activities, and, in particular, in the petrochemical industry. Such goals demand technological innovations in the productive processes and in techniques for treatment and reuse of water in the production chain. The high costs of industrial water, particularly in some metropolitan regions, have stimulated the industries to evaluate the possibilities of water reuse. The objective of this work is to evaluate the feasibility of the UV/H2O2 photochemical process applied to the treatment of process waste water containing polypropylene, aiming at the reuse of the waste water in the as process water in the industrial complex, thus reducing the need for tap water supply and waste water generation rate. The first part of this study consisted of laboratory-scale experiments in a batch photochemical reactor with four different waste water streams to perform the technical and economical feasibility of the photochemical treatment, as well to obtain data on the degradation rate. Based on the results of the first part, the second part of this study consisted of experiments in a continuous photochemical reactor, aimed at obtaining experimental data for reactor scale-up. Experimental results indicate that the UV/H2O2 photodegradation process is able to remove more than 90% of the organic compounds contained in the waste water. However, only waste waters containing relatively low contaminant levels (between 6 and 12 mgC L-1) can be treated at economically favourable costs.
7

Estudo de degradação fotoquímica para reúso de águas de processo em complexo industrial petroquímico. / Study of photochemical degradation to reuse of process water at petrochemical industry.

Daniella Cristina Barbosa de Lira 06 December 2006 (has links)
A racionalização dos recursos hídricos tem sido uma das metas das indústrias em vários setores. Tais metas exigem inovações tecnológicas tanto para novos processos produtivos quanto para novas técnicas de tratamento e reutilização de água na cadeia de produção. Os custos elevados de água industrial no Brasil, particularmente nas regiões metropolitanas, têm estimulado as indústrias nacionais a avaliar as possibilidades de reúso. O objetivo deste trabalho é a aplicação do tratamento de águas de processo contendo polipropileno utilizando radiação ultravioleta e peróxido de hidrogênio, isto é, o sistema UV/H2O2, visando adequá-las para reúso no próprio processo, reduzindo a necessidade de captação de água pré-tratada e de descarte de efluente. A primeira parte do estudo consistiu na realização de experimentos em um sistema fotoquímico de batelada, empregando quatro diferentes correntes efluentes de processo, para a avaliação da viabilidade técnico-econômica do tratamento fotoquímico, bem como para a obtenção de dados referentes à cinética das reações fotoquímicas. Com base nas informações obtidas, na segunda parte do estudo foram realizados experimentos em um sistema fotoquímico contínuo, a fim de obter dados para o aumento de escala para aplicação industrial do processo de tratamento contínuo. Os resultados experimentais indicaram a viabilidade técnica de aplicação do sistema UV/H2O2 utilizando fonte de luz artificial para todas as correntes de processo estudadas, tendo sido alcançados níveis de remoção de matéria orgânica acima de 90%. No entanto, sob o ponto de vista econômico, apenas as correntes com baixo teor de carbono orgânico total dissolvido (COT), entre 6 e 12 mgC L-1, mostraram-se adequadas ao reúso, após o tratamento. / Rationalization of water use has been one of the goals in many industrial activities, and, in particular, in the petrochemical industry. Such goals demand technological innovations in the productive processes and in techniques for treatment and reuse of water in the production chain. The high costs of industrial water, particularly in some metropolitan regions, have stimulated the industries to evaluate the possibilities of water reuse. The objective of this work is to evaluate the feasibility of the UV/H2O2 photochemical process applied to the treatment of process waste water containing polypropylene, aiming at the reuse of the waste water in the as process water in the industrial complex, thus reducing the need for tap water supply and waste water generation rate. The first part of this study consisted of laboratory-scale experiments in a batch photochemical reactor with four different waste water streams to perform the technical and economical feasibility of the photochemical treatment, as well to obtain data on the degradation rate. Based on the results of the first part, the second part of this study consisted of experiments in a continuous photochemical reactor, aimed at obtaining experimental data for reactor scale-up. Experimental results indicate that the UV/H2O2 photodegradation process is able to remove more than 90% of the organic compounds contained in the waste water. However, only waste waters containing relatively low contaminant levels (between 6 and 12 mgC L-1) can be treated at economically favourable costs.

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