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Biological Reactor (biological + reactor)
Selected AbstractsTreatment of beverage-processing wastewater in a three-phase fluidised bed biological reactorINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2008Samwel Victor Manyele Summary This paper presents a study on treatment of beverage-processing wastewater (BPWW) in a three-phase fluidised bed bioreactor (TPFBB). Wastewater samples were introduced in the TPFBB and aerated at optimum liquid and gas flow rates while measuring wastewater parameters [pH, chemical oxygen demand (COD), total suspended solids (TSS), total Kjehldahl nitrogen (TKN) and ammonia-nitrogen (NH3 -N)]. Two different initial pH levels were studied, i.e. 9.0 and 11.5. The pH of the wastewater was observed to level off at 9.3 after 1 day. The TSS dropped by 95% after 5 days, for both initial pH levels. The NH3 -N and TKN dropped to similar final concentration independent of initial pH. The COD removal efficiency was observed to depend on the initial pH level. A highest efficiency of 98% and lowest efficiency of 50% were observed at initial pH of 9.0 and 11.5, respectively. The study results show that TPFBB is capable of treating food-processing wastewater under suitable conditions. [source] Design and application of a membrane bioreactor unit to upgrade and enhance the required performance of an installed wastewater treatment plantASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2010Teresa Castelo-Grande Abstract Wastewater treatment plants (WWTPs) are nowadays common solutions to improve the quality of streams and soils. However, there are still many issues required to be solved within these plants. We were commissioned to redesign a WWTP in Amarante, Portugal, which was not working properly. Among the several units we have designed, there is a membrane bioreactor representing one of the main units of this remodelled WWTP. The biological treatment stage at the upgraded WWTP will take place in the remodelled primary and secondary settlers and in the remodelled and improved biological reactor. Hence, the primary settler is readapted in such a way that it functions as the anoxic area of the biological treatment, while the aerobic treatment will be sequentially performed at the remodelled biological reactor and at the actual secondary settler. Membrane treatment will be performed by using ultrafiltration membranes. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Impact of membrane solid,liquid separation on design of biological nutrient removal activated sludge systemsBIOTECHNOLOGY & BIOENGINEERING, Issue 6 2005M. Ramphao Abstract Installing membranes for solid,liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only in the design of the BNR system itself, but also in the design approach for the whole wastewater treatment plant (WWTP). In multizone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic, and aerobic zones (i.e., fixed volume fractions), the mass fractions can be controlled (within a range) with the interreactor recycle ratios. This zone mass fraction flexibility is a significant advantage in membrane BNR systems over conventional BNR systems with SSTs, because it allows for changing of the mass fractions to optimize biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios in the upper range (fq , 2.0), aerobic mass fractions in the lower range (fmaer < 0.60), and high (usually raw) wastewater strengths, the indicated mode of operation of MBR BNR systems is as extended aeration WWTPs. Although the volume reduction compared with equivalent conventional BNR systems with secondary settling tanks is not as large (40% to 60%), the cost of the membranes can be offset against sludge thickening and stabilization costs. Moving from a flow-unbalanced raw wastewater system to a flow-balanced (fq = 1), low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes from extended aeration to include primary sludge stabilization. The cost of primary sludge treatment then has to be paid from the savings from the increased WWTP capacity. © 2005 Wiley Periodicals, Inc. [source] Bioremediation of Textile Azo Dyes by an Aerobic Bacterial Consortium Using a Rotating Biological ContactorBIOTECHNOLOGY PROGRESS, Issue 4 2003T. Emilia Abraham The degradation of an azo dye mixture by an aerobic bacterial consortium was studied in a rotating biological reactor. Laterite pebbles of particle size 850 ,m to1.44 mm were fixed on gramophone records using an epoxy resin on which the developed consortium was immobilized. Rate of degradation, BOD, biomass determination, enzymes involved, and fish bioassay were studied. The RBC has a high efficiency for dye degradation even at high dye concentrations (100 ,g/mL) and high flow rate (36 L/h) at alkaline pH and salinity conditions normally encountered in the textile effluents. Bioassays (LD-50) using Thilapia fish in treated effluent showed that the percentage mortality was zero over a period of 96 h, whereas the mortality was 100% in untreated dye water within 26 h. Fish bioassay confirms that the effluent from RBC can be discharged safely to the environment. [source] Optimization of the simultaneous removal of nitrogen and organic matter from fishery wastewatersENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2005Estrella Aspé Abstract Anaerobic treatment of saline and protein-rich effluents reduces the organic concentration but forms ammonium that hinders nitrogen removal in a later aerobic treatment. The goal of this work was to optimize the design of a denitrifying,nitrifying system for the simultaneous removal of organic matter and nitrogenous compounds from fishery effluents to meet the Chilean legal standards and to compare pre- and postdenitrification processes in the biological treatment of high-strength effluents to minimize the total volume of biological reactors required. A predenitrifying system, that included three reactors,acidifying anaerobic filter, denitrifying (anoxic) filter, and aerobic-active sludge (nitrifying reactor) with recycle to the denitrifying reactor,reduced nitrogen to 0.33 g of total ammonia nitrogen (TAN) L,1, well above the allowed 0.05 g total nitrogen L,1. The predenitrifying system with a second denitrifying reactor, to which organic matter was added, met the legal organic matter and nitrogen emission concentrations (0.042 g TAN L,1). Conversions were 99.0, 92.5, 90.9, and 99.0% for the anaerobic digestion, first denitrification, nitrification, and second denitrification, respectively. © 2005 American Institute of Chemical Engineers Environ Prog, 2005 [source] The effect of headspace pressure on the performance of a fluidised-bed bioreactorJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2002J Fung Abstract This study compares the biological performance of three fluidised-bed biological reactors under conditions of different headspace pressures. The application of pressure can have a profound effect on the initial rate of bed growth. However, once the fluidised-bed reaches full expansion, the biological performance at higher pressures is greater than those at lower pressures. There appears to be an almost linear relationship between the application of pressure and the performance of the fluidised-bed biological reactors in removing soluble BOD5. This can be attributed to the increase in the oxygen concentration in the bulk liquid and a greater oxygen penetration depth within the biofilm. © 2002 Society of Chemical Industry [source] | |||||||||||||