Download or read book Substrate Interactions During the Degradation of Benzene Toluene and P xylene and Their Effects on Sorption in a Fixed Bed Biological Activated Carbon Reactor written by Myung-Keun Chang and published by . This book was released on 1994 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biological Activated Carbon in Fluidized Bed Reactors for the Treatment of Groundwater Contaminated with Volatile Aromatic Hydrocarbons written by Xianda Zhao and published by . This book was released on 1994 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the Industrial Waste Conference written by and published by . This book was released on 1994 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1995 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1994 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adsorption and Desorption Behavior of Benzene Toluene and P xylene in Ground Water written by Sim Lin Lau and published by . This book was released on 1990 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sorption and Diffusion of Benzene Toluene and the Xylenes in Unsaturated Soil written by Rolf Arands and published by . This book was released on 1994 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sorption and Desorption of Benzene and P xylene on an Unsaturated Desert Soil written by James Hal Davis and published by . This book was released on 1989 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sorption of benzene toluene ethylbenzene and xylenes onto surfactant modified zeolite written by Guifang Tan and published by . This book was released on 2002 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Sorption and Interactive Effects of Benzene and Toluene in Suspended Sediment written by Kerry Lynn Sears and published by . This book was released on 2000 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of PH on the Biodegradation of Benzene Toluene Ethylbenzene M Xylene in Soils written by Amy J. McCormick and published by . This book was released on 1991 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Benzene and Toluene Biodegradation with Different Dissolved Oxygen Concentrations written by Zhuolin Liu and published by . This book was released on 2015 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study reports on benzene and toluene biodegradation under different dissolved oxygen conditions, and the goal of this study is to evaluate and model their removal. Benzene and toluene were tested for obligate anaerobic degradation in batch reactors with sulfate as the electron acceptor. A group of sulfate-reducing bacteria capable of toluene degradation was enriched after 252 days of incubation. Those cultures, originated from anaerobic digester, were able to degrade toluene coupled to sulfate reduction with benzene coexistence, while they were not able to utilize benzene. Methanogens also were present, although their contribution to toluene biodegradation was not defined. Aerobic biodegradation of benzene and toluene by Pseudomonas putida F1 occurred, and biomass production lagged behind substrate loss and continued after complete substrate removal. This pattern suggests that biodegradation of intermediates, rather than direct benzene and toluene transformation, caused bacterial growth. Supporting this explanation is that the calculated biomass growth from a two-step model basically fit the experimental biomass results during benzene and toluene degradation with depleted dissolved oxygen. Catechol was tested for anaerobic biodegradation in batch experiments and in a column study. Sulfate- and nitrate-reducing bacteria enriched from a wastewater treatment plant hardly degraded catechol within 20 days. However, an inoculum from a contaminated site was able to remove 90% of the initial 16.5 mg/L catechol, and Chemical Oxygen Demand was oxidized in parallel. Catechol biodegradation was inhibited when nitrite accumulated, presumably by a toxic catechol-nitrite complex. The membrane biofilm reactor (MBfR) offers the potential for biodegrading benzene in a linked aerobic and anaerobic pathway by controlling the O2 delivery. At an average benzene surface loading of 1.3 g/m2-day and an average hydraulic retention time of 2.2 day, an MBfR supplied with pure O2 successfully achieved 99% benzene removal at steady state. A lower oxygen partial pressure led to decreased benzene removal, and nitrate removal increased, indicating multiple mechanisms, including oxygenation and nitrate reduction, were involved in the system being responsible for benzene removal. Microbial community analysis indicated that Comamonadaceae, a known aerobic benzene-degrader and denitrifier, dominated the biofilm at the end of operation.

Download or read book The Importance and Influence of Groundwater Fluctuations in Phytoremediation written by Jeff Weishaar and published by . This book was released on 2007 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The primary purpose of this research is to study the relationship between microbial degradation and plant uptake of volatile hydrocarbons, such as benzene, toluene, ethylbenzene and xylene. While these compounds are known to biodegrade and are capable of transport into plant tissue, any relationship between the two removal mechanisms remains largely unknown. The goal of this work is to better understand the interactions of these multiple biological processes within a phytoremediation effort"--Introduction, leaf 3.

Download or read book The Treatment of Benzene Toluene Ethylbenzene and O Xylene Using Two Phase Partitioning Bioscrubbers written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examined the biological treatment of gas streams containing benzene, toluene, ethylbenzene and o-xylene (BTEX) using solid-liquid two-phase partitioning bioscrubbers (SL-TPPBs). SL-TPPBs consist of a cell containing aqueous phase and a polymeric solid phase that sequesters poorly water soluble and/or toxic substrates, mitigating substrate toxicity in the aqueous phase and improving the gas mass transfer during treatment of VOC contaminated gases. An initial investigation of oxygen transport determined that the polymers in a stirred-tank SL-TPPB enhance gas-liquid mass transfer. In addition, a study on biodegradation kinetics of BTEX by a bacterial consortium identified and quantified substrate interactions such as inhibition, enhancement and cometabolism. The stirred-tank SL-TPPB was then experimentally investigated for treatment of BTEX gas streams during steady-state and dynamic step-change operation to determine performance of the system relative to other biotreatment methods. A mathematical model was developed to predict system performance, which included the microbial kinetic model structure and parameters estimated during kinetic and oxygen mass transfer studies. As a less energy intensive alternative, an airlift SL-TPPB was operated and characterized. The airlift SL-TPPB was compared to an airlift liquid-liquid TPPB (silicone oil as sequestering phase) and a single phase airlift over dynamic step-change loadings, which showed that the airlift SL-TPPB outperformed the single phase airlift by>30% and had similar performance to the liquid-liquid airlift. However, the airlift SL-TPPB performance was lower relative to the stirred-tank SL-TPPB by>15%. Steady-state operation of the airlift SL-TPPB identified a range of operating conditions that provided maximum performance and conditions that were not oxygen limited. This prompted a study of oxygen mass transfer and hydrodynamics in the airlift system, which identified that the addition of polymers to.

Download or read book Degradation of Benzene Toluene Ethybenzene and Xylene by Isilated Microorganisms from Petronas Gas Plant at Kertih Terengganu written by Hamid Reza Salsali and published by . This book was released on 1999 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: A total of 38 isolates originating from five different sources of sediments, and contaminated soils from Petronas Gas Plant at Kertih, Terengganu were obtained through enrichment culture method using 0.1% (v/v) of benzene, toluene, ethylbenzene, and xylene or mixture of them as their sole energy and carbon sources. Most of the isolates were from S5 (Resindential area) and the least from S1 (equalization basin). Out of this, 11 good isolates were able to grow in varying hydrocarbon concentration up to 50% (v/v) BTEX. Only isolated No.4 showed extremely good growth in concentration up to 80% (v/v) of BTEX. Using benzene at 60% (v/v), the growth rate was observed to be highest durong the first 2 hours, while degradation rate and percentage of removal by using isolate No. 4 showed 1.5E-04 mM/s and 75% respectively. For toluene at 60% (v/v), the growth ratewas highest during the first 3 hours, while degradation rate and percentage of removal were 5E-05 mM/s and 70% respectively. In the case ethylbenzene at 60% (v/v), the growth rate was highest during the first 7 hours, while degradation rate and percentage of removal by using same isolate showed 1E-04 mM/s and 98% respectively. For xylene at 60% (v/v), the growth rate was highest during the first 5 hours, while degradation rate and percentage of removal achieved were 5.35E-04 mM/s and 8.9% respectively. In general, all the isolates had tolerated the organuc solvent (BTEX), which may be due to the adaptability of the cell membrane through a metabolic or enzymatic properties. Both High- Performances Liquid Chromatography and Gas Chromatography Mass-Spectra profile had clearly showed a BTEX-peask area ratio reduction, where the isolates were shown to biodegrade the hydrocarbon either by mineralization or biotrasfromation. However, based on the almost complex peak reduction as well as appereance of unidentified peaks, it may be suggested that BTEX can be degraded by naturally present microorganisms which was identified at Petronas Gas Berhad site.

Download or read book Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

Download or read book Combined Air Stripping and Biodegradation of Benzene Toluene and Xylenes in Permeable Barriers written by Curtis P. McHaley and published by . This book was released on 1991 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: