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Biological Wastewater Treatment (biological + wastewater_treatment)
Selected AbstractsBook Review: Fundamentals of Biological Wastewater Treatment.ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2007By U. Wiesmann, E.-M., I. S. Choi No abstract is available for this article. [source] Adaptive recurrent neural network control of biological wastewater treatmentINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2005Ieroham S. Baruch Three adaptive neural network control structures to regulate a biological wastewater treatment process are introduced: indirect, inverse model, and direct adaptive neural control. The objective is to keep the concentration of the recycled biomass proportional to the influent flow rate in the presence of periodically acting disturbances, process parameter variations, and measurement noise. This is achieved by the so-called Jordan Canonical Recurrent Trainable Neural Network, which is a completely parallel and parametric neural structure, permitting the use of the obtained parameters, during the learning phase, directly for control system design. Comparative simulation results confirmed the applicability of the proposed control schemes. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 173,193, 2005. [source] The use of 3,3,,4,,5-tetrachlorosalicylanilide as a chemical uncoupler to reduce activated sludge yieldJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2004Ying Xu Chen Abstract To determine whether chemical additions can be used to reduce sludge production in biological wastewater treatment, 3,3,,4,,5-tetrachlorosalicylanilide (TCS) was added to activated sludge cultures as a metabolic uncoupler. Batch tests confirmed that TCS is an effective chemical uncoupler in reducing the sludge yield at concentrations greater than 1.0 mg dm,3; a TCS concentration of 1.0 mg dm,3 reduced sludge yield by approximately 50%. Substrate removal capability and effluent nitrogen concentration were not affected adversely by the presence of TCS when dosed every other day in a range of 2.0,3.6 mg dm,3 during the 40-day operation of activated sludge batch cultures. Such sludge growth reduction was associated with the enhancement of microbial activities in terms of the specific oxygen uptake rate and dehydrogenase activity. Sludge settleability of the treated and control samples was qualitatively comparable and not significantly different. Filamentous bacteria continued to grow in sludge flocs only in the control reactor at the end of the 40-day trial. These results suggest that TCS treatment of activated sludge systems may reduce excess sludge yield. Copyright © 2003 Society of Chemical Industry [source] Genomics of biological wastewater treatmentMICROBIAL BIOTECHNOLOGY, Issue 5 2008Roland J. Siezen [source] Novel application of oxygen-transferring membranes to improve anaerobic wastewater treatmentBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2005Anthony S. Kappell Abstract Anaerobic biological wastewater treatment has numerous advantages over conventional aerobic processes; anaerobic biotechnologies, however, still have a reputation for low-quality effluents and operational instabilities. In this study, anaerobic bioreactors were augmented with an oxygen-transferring membrane to improve treatment performance. Two anaerobic bioreactors were fed a synthetic high-strength wastewater (chemical oxygen demand, or COD, of 11,000 mg l,1) and concurrently operated until biomass concentrations and effluent quality stabilized. Membrane aeration was then initiated in one of these bioreactors, leading to substantially improved COD removal efficiency (>95%) compared to the unaerated control bioreactor (,65%). The membrane-augmented anaerobic bioreactor required substantially less base addition to maintain circumneutral pH and exhibited 75% lower volatile fatty acid concentrations compared to the unaerated control bioreactor. The membrane-aerated bioreactor, however, failed to improve nitrogenous removal efficiency and produced 80% less biogas than the control bioreactor. A third membrane-augmented anaerobic bioreactor was operated to investigate the impact of start-up procedure on nitrogenous pollutant removal. In this bioreactor, excellent COD (>90%) and nitrogenous (>95%) pollutant removal efficiencies were observed at an intermediate COD concentration (5,500 mg l,1). Once the organic content of the influent wastewater was increased to full strength (COD = 11,000 mg l,1), however, nitrogenous pollutant removal stopped. This research demonstrates that partial aeration of anaerobic bioreactors using oxygen-transferring membranes is a novel approach to improve treatment performance. Additional research, however, is needed to optimize membrane surface area versus the organic loading rate to achieve the desired effluent quality. © 2005 Wiley Periodicals, Inc. [source] | ||||||||||