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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

Determination of Alkylphenol and Alkylphenol Polyethoxylates in Water and Sediments by Liquid Chromatography Tandem Mass Spectrometry

Cho, Chun-Liang 30 August 2010 (has links)
Alkylphenol polyethoxylates are one of the most importantclasses of nonionic surfactants. They are widely used in the household detergents and dyeing industry. Indeed, alkylphenols have been estimated that they are persistence organic pollutions which are not easily biodegraded by microorganisms and demonstrated as endocrine disruptors. Therefore alkylphenols regard as environmental hormones. The purpose in this research is developing the method which can be used for detection and quantification of alkylphenols and alkylphenol polyethoxylates in waters and sediments. LC-MS/MS was used as the analytical instrument which can analyze alkylphenols combined with long ethoxylate chain with improved sensitivity and selectivity. The extraction is liquid-liquid extraction. The mobile phase consisting of acetonitrile, water and methanol(43/14/43%, v/v/v) with 20mM ammonium acetate added was used for HPLC separation. The recoveries of alkylphenols and alkylphenol polyethoxylates from water and sediments were 83.0~95.1% and 84.8~94.6%. Decision limit(CC£\) and detection capability(CC£]) of water were 0.10~1.65 ng/L and 0.13~2.03 ng/L. CC£\ and CC£] of sediments were 0.05~0.95 ng/g and 0.06~1.18 ng/g.
2

Determination of alkylphenol polyethoxylates in environmental water by liquid chromatography-tandem mass spectrometry

Lan, Yi-wen 19 August 2011 (has links)
A LC-MS/MS method for the analysis of alkylphenol polyethoxylates in environmental waters was developed in this study. Preatment procedures including liquid-liquid extraction and solid phase extraction were compared, it¡¦s concluded that solid phase extraction is the more suitable way due to higher recovery and better stability for the analytical results. The recovery of nonylphenol polyethoxylate and octylphenol polyethoxylate were 62.3-110.7 % and 64.9-112.0 %, limit of detection were 17.60-174.9 ng/L and 7.40-53.56 ng/L. Enviromental water samples were collected from eight sampling sites along Love River in Kaohsiung City to investigate the contents of alkylphenol polyethoxylates. The highest concentration of total alkylphenol polyethoxylates was observed at Ming-Cheng Bridge which located at the upstream of Love River. For all of the analyzed compounds, the concentration of octylphenol tetraethoxylate (40.46 £gg/L) was the highest in all of the sampling sites. It¡¦s also noticed the concentration of octylphenol polyethoxylate (20.11 £gg/L) was higher than that of nonylphenol polyehtoxylate (128.04 £gg/L).
3

Investigation of alkylphenol polyethoxylates in the aquatic environment of Hengchun peninsula

Chao, Ching-hung 07 September 2012 (has links)
In April and June 2012, environmental water samples were collected from fourteen sampling sites in Hengchun peninsula to investigate the contents of alkylphenol polyethoxylates. A solid phase extraction combined with LC-MS/MS method for the analysis of alkylphenol polyethoxylates in environmental waters was developed in this study. The mobile phase used methanol gradient elution with deionized water. The recovery of nonylphenol polyethoxylate and octylphenol polyethoxylate were 68~94 % and 65~93 %, limit of detection were 1.89~54.20 ng/L and 0.44~39.31 ng/L, limit of quantitative were 6.29~181 ng/L and 1.48~131 ng/L. The SsuChung river contents of NPEO and OPEO were 15.64~36.29 £gg/L and 3.14~7.37 £gg/L. The Paoli river contents of NPEO and OPEO were 16.65~76.41 £gg/L and 5.66~18.80 £gg/L. The Hou Bay contents of NPEO and OPEO were 34.79~66.72 £gg/L and 7.77~19.03 £gg/L. The Shihniou river contents of NPEO and OPEO were 26.67 £gg/L and 6.68 £gg/L. The Wanli Tong, Baisha, Houbi Lake, South Bay, Caesar and Siangjiao Bay contents of NPEO and OPEO were 14.17~48.82 £gg/L and 3.88~14.79 £gg/L. The dry season concentration contents of alkylphenol polyethoxylates were high than the wet season. The concentration of nonylphenol polyethoxylate was higher than that of octylphenol polyehtoxylate.
4

Tratabilidade de águas residuárias de indústrias petroquímicas - estudo de caso. / Treatability of petrochemical industries wastewaters - case study.

Hilsdorf, Antonio Sérgio de Carvalho 02 September 2008 (has links)
O tratamento de águas residuárias industriais, submetido constantemente a cargas de choque, é pouco estudado no Brasil, sendo limitado o grau de conhecimento que se tem no mundo sobre os mecanismos de remoção de disruptores endócrinos nos sistemas de tratamento físico-químicos e biológicos. O presente trabalho traz um estudo de caso, envolvendo uma indústria com uma composição de produtos muito diversificada, com despejos líquidos de unidades isoladas de qualidades diversas e que tem como uma das principais matérias-primas, nonil fenóis, conhecidos disruptores endócrinos. Os mecanismos de remoção de carga orgânica e a avaliação da toxicidade da água residuária ao processo biológico de tratamento foram estudados em escala de laboratório, enquanto que a sua tratabilidade por coagulação, floculação, flotação com ar dissolvido seguido de sistema de lodos ativados, em escala piloto. Avaliou-se, também, a aplicabilidade do tratamento biológico com carvão ativado em pó. A grande variação qualitativa e quantitativa da água residuária bruta requer uma unidade de equalização com tempo de detenção de pelo menos 30 horas. O maior responsável por esta variação de qualidade é o processo da unidade química, cujo efluente é proveniente de lavagens de tanques e reatores. Apesar da reduzida eficiência de remoção de DQO obtida com a coagulação, floculação e flotação com ar dissolvido (20 a 30%), constatou-se que este tratamento é essencial para a redução da toxicidade ao processo biológico. A dosagem de coagulante e o pH ótimos variam conforme a característica do despejo e devem ser determinadas diariamente. No sistema biológico, observou-se uma remoção significativa da DQO do efluente bruto gerado na indústria, não apenas por biodegradação, mas também por volatilização e adsorção. Os testes de bancada evidenciaram remoções de DQO por arraste com ar de 47 a 77 % e por adsorção no lodo biológico, de 42%. Apesar dos constantes choques de carga orgânica e de poluentes tóxicos, conseguiu-se atingir o estado estacionário com variações máximas da concentração de sólidos em suspensão voláteis no tanque de aeração entre 20 e 30%. Neste período, a idade do lodo situou-se em torno de 25 a 30 dias e o tempo de detenção hidráulico foi de 3,8 dias. A eficiência média de remoção de DQO neste período foi de 86%. Os testes com a unidade piloto demonstraram que a utilização de carvão ativado em pó (CAP) produz resultados satisfatórios, comprovando a redução de poluentes tóxicos da água residuária e refletindo em uma significativa melhora na biodegradabilidade do efluente, com aumento da concentração de sólidos em suspensão voláteis no tanque de aeração (de 1380 mg/L para 3820 mg/L) e redução da amplitude de variação da DQO do efluente tratado que passou de 600 a 3200 mgO2/L para o sistema sem CAP para 300 a 600 mgO2/L para o sistema com CAP. Notou-se, também, com a adição de CAP, melhoria na sedimentação do lodo. Pode-se concluir também que o sistema de tratamento atendeu a legislação atual do Estado de São Paulo, com uma remoção média de 80% da DBO5. / Wastewater treatment systems continuously receiving shock loads and the behavior of contaminants under unsteady state conditions are not very well documented in our country, with limited degree of knowledge in the world on the removal of specific pollutants like endocrine disrupting chemicals (EDC) in physical chemical and biological wastewater treatment systems. The present work brings a case study regarding an industry which wastewaters were generated from plants with multiproducts and campaign production with variable composition, and with nonylphenols as one of their raw materials which is known as an endocrine disrupting chemical. The organic load and toxicity removal mechanisms of the wastewater to the biological treatment were studied in bench scale whilst their treatability was evaluated through coagulation, flocculation, dissolved air flotation followed by activated sludge, in pilot scale. The feasibility of the addition of powdered activated carbon to the biological system was also studied. The large qualitative and quantitative variability of the wastewater requires an equalization time of at least 30 hours. The main responsible for this variability in quality is the chemical unit process which wastewaters are originated from reactors and tanks cleanings. Although the low efficiency in COD removal obtained with coagulation, flocculation and dissolved air flotation (20 to 30%), it was found that this process is essential to the toxicity reduction for the biological process. Optimum pH and coagulant dose vary with the wastewater characteristics, and must be determined on a daily basis. On the biological system, it was observed important raw wastewater COD elimination not only through biodegradation, but also through volatilization and adsorption. Bench tests revealed COD elimination of 47 to 77% by air stripping and 42% by adsorption onto the biological sludge. Despite of constant organic and toxic shock loads, it had been possible to reach the steady state during which the maximum variation on the volatile suspended solids concentration was 20 to 30%. During this period, sludge age was around 25 to 30 days, and the hydraulic detention time was 3,8 days. Average efficiency on COD removal in this period was 86%. Tests results with PAC dosage on the pilot plant showed satisfactory, proving the reduction of toxic compounds from the wastewater and resulting in biodegradability improvement. The increase of volatile suspended solids in the aeration tank was from 1380 mg/L to 3820 mg/L, and reduction in the range of variation of remaining treated water COD from 600 to 3200 mgO2/L (system without CAP) down to 300 to 600 mgO2/L (system with CAP). The improvement on the sludge sedimentation with PAC addition was also remarkable. One can also conclude the treatment system attained the current legislation of the State of São Paulo, with 80% BOD5 removal.
5

Tratabilidade de águas residuárias de indústrias petroquímicas - estudo de caso. / Treatability of petrochemical industries wastewaters - case study.

Antonio Sérgio de Carvalho Hilsdorf 02 September 2008 (has links)
O tratamento de águas residuárias industriais, submetido constantemente a cargas de choque, é pouco estudado no Brasil, sendo limitado o grau de conhecimento que se tem no mundo sobre os mecanismos de remoção de disruptores endócrinos nos sistemas de tratamento físico-químicos e biológicos. O presente trabalho traz um estudo de caso, envolvendo uma indústria com uma composição de produtos muito diversificada, com despejos líquidos de unidades isoladas de qualidades diversas e que tem como uma das principais matérias-primas, nonil fenóis, conhecidos disruptores endócrinos. Os mecanismos de remoção de carga orgânica e a avaliação da toxicidade da água residuária ao processo biológico de tratamento foram estudados em escala de laboratório, enquanto que a sua tratabilidade por coagulação, floculação, flotação com ar dissolvido seguido de sistema de lodos ativados, em escala piloto. Avaliou-se, também, a aplicabilidade do tratamento biológico com carvão ativado em pó. A grande variação qualitativa e quantitativa da água residuária bruta requer uma unidade de equalização com tempo de detenção de pelo menos 30 horas. O maior responsável por esta variação de qualidade é o processo da unidade química, cujo efluente é proveniente de lavagens de tanques e reatores. Apesar da reduzida eficiência de remoção de DQO obtida com a coagulação, floculação e flotação com ar dissolvido (20 a 30%), constatou-se que este tratamento é essencial para a redução da toxicidade ao processo biológico. A dosagem de coagulante e o pH ótimos variam conforme a característica do despejo e devem ser determinadas diariamente. No sistema biológico, observou-se uma remoção significativa da DQO do efluente bruto gerado na indústria, não apenas por biodegradação, mas também por volatilização e adsorção. Os testes de bancada evidenciaram remoções de DQO por arraste com ar de 47 a 77 % e por adsorção no lodo biológico, de 42%. Apesar dos constantes choques de carga orgânica e de poluentes tóxicos, conseguiu-se atingir o estado estacionário com variações máximas da concentração de sólidos em suspensão voláteis no tanque de aeração entre 20 e 30%. Neste período, a idade do lodo situou-se em torno de 25 a 30 dias e o tempo de detenção hidráulico foi de 3,8 dias. A eficiência média de remoção de DQO neste período foi de 86%. Os testes com a unidade piloto demonstraram que a utilização de carvão ativado em pó (CAP) produz resultados satisfatórios, comprovando a redução de poluentes tóxicos da água residuária e refletindo em uma significativa melhora na biodegradabilidade do efluente, com aumento da concentração de sólidos em suspensão voláteis no tanque de aeração (de 1380 mg/L para 3820 mg/L) e redução da amplitude de variação da DQO do efluente tratado que passou de 600 a 3200 mgO2/L para o sistema sem CAP para 300 a 600 mgO2/L para o sistema com CAP. Notou-se, também, com a adição de CAP, melhoria na sedimentação do lodo. Pode-se concluir também que o sistema de tratamento atendeu a legislação atual do Estado de São Paulo, com uma remoção média de 80% da DBO5. / Wastewater treatment systems continuously receiving shock loads and the behavior of contaminants under unsteady state conditions are not very well documented in our country, with limited degree of knowledge in the world on the removal of specific pollutants like endocrine disrupting chemicals (EDC) in physical chemical and biological wastewater treatment systems. The present work brings a case study regarding an industry which wastewaters were generated from plants with multiproducts and campaign production with variable composition, and with nonylphenols as one of their raw materials which is known as an endocrine disrupting chemical. The organic load and toxicity removal mechanisms of the wastewater to the biological treatment were studied in bench scale whilst their treatability was evaluated through coagulation, flocculation, dissolved air flotation followed by activated sludge, in pilot scale. The feasibility of the addition of powdered activated carbon to the biological system was also studied. The large qualitative and quantitative variability of the wastewater requires an equalization time of at least 30 hours. The main responsible for this variability in quality is the chemical unit process which wastewaters are originated from reactors and tanks cleanings. Although the low efficiency in COD removal obtained with coagulation, flocculation and dissolved air flotation (20 to 30%), it was found that this process is essential to the toxicity reduction for the biological process. Optimum pH and coagulant dose vary with the wastewater characteristics, and must be determined on a daily basis. On the biological system, it was observed important raw wastewater COD elimination not only through biodegradation, but also through volatilization and adsorption. Bench tests revealed COD elimination of 47 to 77% by air stripping and 42% by adsorption onto the biological sludge. Despite of constant organic and toxic shock loads, it had been possible to reach the steady state during which the maximum variation on the volatile suspended solids concentration was 20 to 30%. During this period, sludge age was around 25 to 30 days, and the hydraulic detention time was 3,8 days. Average efficiency on COD removal in this period was 86%. Tests results with PAC dosage on the pilot plant showed satisfactory, proving the reduction of toxic compounds from the wastewater and resulting in biodegradability improvement. The increase of volatile suspended solids in the aeration tank was from 1380 mg/L to 3820 mg/L, and reduction in the range of variation of remaining treated water COD from 600 to 3200 mgO2/L (system without CAP) down to 300 to 600 mgO2/L (system with CAP). The improvement on the sludge sedimentation with PAC addition was also remarkable. One can also conclude the treatment system attained the current legislation of the State of São Paulo, with 80% BOD5 removal.

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