Anaerobic fixed film wastewater treatment
ABSTRACT The anaerobic methane fermentation process has long been used in the field of wastewater engineering in sludge processing, mainly for waste stabilization and solids reduction. Recently, major advances in the fundamental understanding of the process microbiology and biochemistry, along with the development of new reactor configurations have promoted a resurgence of interest in the use of this technology for the processing of liquid industrial and municipal wastewaters. Three of these new processes, the anaerobic filter, expanded/fluidized bed, and upflow anaerobic sludge blanket, are discussed.Each of these processes is a fixed film process, which enables the attainment of high solids retention times for good system efficiency and stability, with low hydraulic retention times for system economy. Fixed film anaerobic processes are able to realize many of the benefits of anaerobic processes while overcoming many of the problems historically associated with anaerobic processes.Each of the processes is described, and examples are presented for industrial and municipal applications. Finally, the processes are qualitatively compared. At present, it is not possible to say which reactor configuration is best. In fact, the selection is often dependent on wastewater characteristics, local factors, and several other factors. More full-scale data and operating experience along with basic research needs are needed to clarify further this situation, and to design these systems optimally.
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ABSTRACT: In the present study, attempts are made to optimize digestion time, initial feed pH, feed temperature, and feed flow rate (organic loading rate, OLR) for maximum yield of methane gas and maximum removal of chemical oxygen demand (COD) and biological oxygen demand (BOD) of sugar industry wastewaters in three-phase fluidized-bed bioreactor. Methane gas is analysed by using flame-ionisation detector (FID). The optimum digestion time is 8 h and optimum initial pH of feed is observed as 7.5. The optimum temperature of feed is 40°C and optimum feed flow rate is 14 L/min with OLR 39.513 kg COD/m3 h. OLR is calculated on the basis of COD inlet in the bioreactor at different flow rates. The maximum methane gas concentration is 61.56% (v/v) of the total biogas generation at optimum biomethanation process parameters. The maximum biogas yield rate is 0.835 m3/kg COD/m3 h with maximum methane gas yield rate (61.56%, v/v) of 0.503 m3/kg COD/m3 h at optimum parameters. The maximum COD and BOD reduction of the sugar industry wastewaters are 76.82% (w/w) and 81.65% (w/w) at optimum biomethanation parameters, respectively.Les études continues actuelles sont entreprises pour créer un processus de digestion anaérobie efficace des eaux usées de l'industrie du sucre pour la production de biogaz à l'aide de boues digérées de façon active provenant d'une station de traitement des eaux usées dans un réacteur à lit fluidisé à trois phases. Le gaz méthane est analysé en utilisant un détecteur à ionisation de flamme qui est un détecteur du chromatographe en phase gazeuse. Le temps de digestion optimal est de 8 h et le pH initial optimal de l'approvisionnement est observé comme 7,5 respectivement. La température optimale de l'approvisionnement est de 40 şC et le débit optimal de l'approvisionnement est de 14 L/min avec un taux de charge organique maximal de 39,513 kg DCO m−3 h−1 respectivement. Les taux de charge organique sont calculés sur la base de l'entrée de DCO dans le réacteur à divers débits. L'expansion maximale du lit est observée à 23,67 m à un débit d'approvisionnement optimal de 14 L/min. La concentration maximale de gaz méthane (CH4) est de 63,56 % (v/v) de la production totale de biogaz aux paramètres de bioprocédés optimaux. Le taux de rendement maximal de biogaz est de 0.835 m3/kg DCO m−3 h−1 avec un taux de rendement maximal de gaz méthane de 0.530 m3/kg DCO m−3 h−1 respectivement aux paramètres optimaux. Le retrait maximal de DCO et DBO des eaux usées de l'industrie du sucre est de 76,82 % (w/w) et 81,65 % (w/w) avec un taux de charge organique de 39.513 kg DCO m−3 h−1 respectivement.The Canadian Journal of Chemical Engineering 06/2010; 88(6):1085 - 1090. · 1.00 Impact Factor
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ABSTRACT: The nitrogen removal from wastewater and landfill leachate has become a vital part of the overall treatment process because nitrogen compounds have the significant impact on the environment. Generally, biological nitrogen removal is used for nitrogen elimination from wastewater. In the last years, newly advanced anaerobic reactor systems such as up flow anaerobic sludge blanket (UASB), anaerobic filter (AF), anaerobic fluidized bed (FB), anaerobic sequencing batch reactor (AnSBR) and other anaerobic reactors have been used for the treatment of low strength wastewater, landfill leachate and, etc. The aims of this study were the review on the anaerobic digestion, some kinds of bio-reactors and nitrogen removal from wastewater and landfill leachate by bio-reactor. Many investigations showed that the bio-reactor and anaerobic treatments could be reducing nitrogen from wastewater and landfill leachate. Additionally, many studies also were reported some environmental factors such as pH, temperature, ammonia, alkalinity and nutrients affecting on anaerobic digestion.Advances in Environmental Biology 07/2012; 6(7-1998-1066):2143-2150.
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ABSTRACT: The potentials of using the hydraulic technique in combined unit for municipal wastewater treatment were studied. A combined unit in which processes of coagulation, flocculation and sedimentation, has been designed utilizing hydraulic mixing instead of mechanical mixing. A jar test treatability study has been conducted to locate the optimum dose of the coagulants to be used. Alum, ferrous sulfate, ferric sulfate, a mixture of ferric and ferrous sulfates, and mixture of lime and ferrous sulfate were all tested. A pilot unit was constructed in the existing wastewater treatment plant at El Mansoura governorate located in north Egypt. The optimum dose of coagulants used in the combined unit gives removal efficiencies for COD, BOD, and total phosphorous as 65%, 55%, and 83%, respectively.Journal of Advanced Research. 10/2012; 3(4):331–336.