Biochemical oxygen demand (BOD) is a widely used index of water-quality assessment. Since bioelectrochemical BOD biosensors require anaerobic conditions for anodic reactions, they are not directly used in aerobic environments such as aeration tanks. Normally, the BOD biosensors are closed-type, where the anode is packed inside a closed chamber to avoid exposure to oxygen. In this study, a novel...

Thermophilic campylobacters were isolated from three sewage plants in Rio de Janeiro, RJ, Brazil and identified. Laboratory analysis of 390 sewage samples showed the presence of 169 thermophilic strains. The results demonstrated that human and animal pathogenic biotypes could be isolated from activated sludge during the initial processing steps. The aeration tank could be considered a barrier t...

The modified rotating simplex method has been successfully used to determine the best combination of agitation rate and aeration rate for maximum production of extracellular proteases by Staphylococcus aureus mutant RC128, in a stirred tank bioreactor operated in a discontinuous way. This mutant has shown altered exoprotein production, specially enhanced protease production. Maximum production ...

Single-tank simultaneous nitrification and denitrification (SNdN) processes can potentially eliminate the need for separate tanks and for recycling mixed liquor from oxic nitrifying zones to the typically upstream anoxic zones for denitrification. However, the conditions involved are more susceptible to sludge bulking by excessive growth of filamentous bacteria. This study was aimed at identify...

Microbubble aeration has been recognized as a tool to improve dissolved oxygen and fish culture performance in limited water aquaculture. This research aims investigate the effect of microbubble on increasing oxygen, performance, stress resistance red tilapia. The study used 3 treatments aerations namely microbubble, blower, without with replicates each. Red tilapia weighing 115.27±3.93 g were ...

An intermittent aerator was newly developed to reduce energy costs in a flat-sheet ceramic membrane bioreactor (MBR) for industrial wastewater treatment. Large air bubbles were supplied over short time interval by the improved technology at bottom of membrane. Performance tests carried out pilot system with two cassettes immersed tank 1-MGD demonstration plant Jurong Water Reclamation Plant (JW...

The gas transfer in aeration systems is broken into two processes: gas transfer at the bubble interface and gas transfer at the water surface. Experiments were conducted to separate these two sources of dissolved gas. Oxygen absorption was measured in a laboratory tank with air being diffused through a porous diffuser and then with nitrogen gas being diffused. The combination of these experimen...