Recently added articles from Water Environment Research:

The Future of Nutrient Removal Research and Practice ... Revisited

May 01, 2008; Celmer, Dominika; Kinnear, David J ... In 1914, Ardern and Lockett introduced activated sludge technology to wastewater treatment facilities (Ardern, E.; Lockett, W.T. [1914] Experiments on Oxidation of Sewage without the Aid of Filters. J. Soc. Chem. Ind., 33, 523) and provided a means for larger cities to begin protection of water ...

Significance of Design and Operational Variables in Chemical Phosphorus Removal

May 01, 2008; Szabó, A; Takács, I; Murthy, S; Daigger, G T; Licskó, I; Smith, S ... ABSTRACT: Batch and continuous experiments using model and real wastewaters were conducted to investigate the effect of metal salt (ferric and alum) addition in wastewater treatment and the corresponding phosphate removal from a design and operational perspective. Key factors expected to ...

Denitrification with Carbon Addition-Kinetic Considerations

May 01, 2008; Dold, P; Takács, I; Mokhayeri, Y; Nichols, A; Hinojosa, J; Riffat, R; Bott, C; Bailey, W; Murthy, S ... ABSTRACT: The Blue Plains Advanced Wastewater Treatment Plant (Washington, D.C.) uses methanol as an external carbon source in a postdenitrification process, to achieve low effluent total nitrogen concentrations. This becomes more difficult in winter, at lower mixed liquor temperatures ...

Predicted Distributed State Effects on Enhanced Biological Phosphorus Removal in a 5-Stage Bardenpho Wastewater Treatment Configuration

May 01, 2008; Schuler, Andrew J; Xiao, Yao ... ABSTRACT: Conventional wastewater treatment simulation programs use a "lumped" approach, where process rates are calculated using bulk concentrations of biomass and microbial storage products. A recently developed distributed, or agent-based, approach, where individual bacteria are ...

Bioavailability of Dissolved Organic Nitrogen in Treated Effluents

May 01, 2008; Urgun-Demirtas, Meltem; Sattayatewa, Chakkrid; Pagilla, Krishna R ... ABSTRACT: The research objective was to assess dissolved organic nitrogen (DON) bioavailability in wastewater effluents from a pilot-scale nitrification plant and a laboratory-scale total nitrogen (TN) removal plant. The DON bioavailability was assessed using a 14-day bioassay protocol ...

Improved Computational Model (AQUIFAS) for Activated Sludge, Integrated Fixed-Film Activated Sludge, and Moving-Bed Biofilm Reactor Systems, Part I: Semi-Empirical Model Development

May 01, 2008; Sen, Dipankar; Randall, Clifford W ... ABSTRACT: Research was undertaken to develop a model for activated sludge, integrated fixed-film activated sludge (IFAS), and moving-bed biofilm reactor (MBBR) systems. The model can operate with up to 12 cells (reactors) in series, with biofilm media incorporated to one or more cells, ...

Nitrifying Genera in Activated Sludge May Influence Nitrification Rates

May 01, 2008; Dytczak, M A; Londry, K L; Oleszkiewicz, J A ... ABSTRACT: Sequencing batch reactors were acclimated under aerobic and alternating anoxic/aerobic conditions. Greater nitrification rates in the alternating reactor were investigated by comparing environmental conditions. In the alternating reactor, pH, alkalinity, oxygen, and nitrite ...

Phosphate Complexation Model and Its Implications for Chemical Phosphorus Removal

May 01, 2008; Smith, S; Takács, I; Murthy, S; Daigger, G T; Szabó, A ... ABSTRACT: A phosphate complexation model is developed, in an attempt to understand the mechanistic basis of chemically mediated phosphate removal. The model presented here is based on geochemical reaction modeling techniques and uses known surface reactions possible on hydrous ferric ...

Enhanced Removal of Heavy Metals in Primary Treatment Using Coagulation and Flocculation

May 01, 2008; Johnson, Pauline D; Girinathannair, Padmanabhan; Ohlinger, Kurt N; Ritchie, Stephen; Teuber, Leah; Kirby, Jason ... ABSTRACT: The goal of this study was to determine the removal efficiencies of chromium, copper, lead, nickel, and zinc from raw wastewater by chemically enhanced primary treatment (CEPT) and to attain a total suspended solids removal goal of 80%. Operating parameters and chemical doses ...

Levels and Distribution of DDT in the Cinca River (Spain)

May 01, 2008; Ormad, M P; Ratia, J S; Rodriguez, L; Ovelleiro, J L ... ABSTRACT: The evolution over time of the levels and distribution of dichlorodiphenyltrichloroethane (DDT) in water, surface sediments, and fish from the River Cinca (Spain), a tributary of the River Ebro, during the period 1999 to 2004, was investigated by means of gas chromatography ...

Errata

May 01, 2008; Anonymous ... Corrections follow for Choi, Y.; Johnson, K.; Hayes, D.; Xu, H. (2008) Pilot-Scale Aerated Submerged Biofilm Reactor for Organics Removal and Nitrification at Cold Temperatures. Water Environ. Res., 80, ...