The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket) reactor is presented. Two lab-scale UASB reactors (10.5 L) were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received i...

Abstract Generally, abstracted groundwater is aerated, leading to iron (Fe2+) oxidation Fe3+ and precipitation as Fe3+-(hydr)oxide (HFO) flocs. This practice of passive treatment, however, not considered a barrier for arsenic (As), removal efficiencies vary widely (15–95%), depending on Fe/As ratio. study hypothesizes that full utilization the adsorption capacity native-Fe2+ based HFO flocs ham...

Nickel-containing carbon monoxide dehydrogenases (CODHs) reversibly catalyze the oxidation of carbon monoxide to carbon dioxide and are of vital importance in the global carbon cycle. The unusual catalytic CODH C-cluster has been crystallographically characterized as either a NiFe(4)S(4) or a NiFe(4)S(5) metal center, the latter containing a fifth, additional sulfide that bridges Ni and a uniqu...

Membrane-aerated biofilm reactors (MABR) are being applied for autotrophic nitrogen removal, yet control of turnover remains challenging in MABR counter-diffusion biofilms. In this study, we regulated microbial activities two lab-scale MABRs by providing continuous versus intermittent aeration. Nitrogen consumption different functional groups was estimated from bulk measurements via a mass bala...

A full scale swine (300 pigs) waste treatment system, including a solid/liquid separation unit (3 m) with a solids holding tank (1.2 m) and a liquid holding tank (20 m), two anaerobic reactors (10 m each) in series, an intermittent aeration unit (20 m), a sedimentation/polishing unit (20 m) and a sludge dewatering bed (17 m), was used to investigate the impact of integrating an intermittent aer...

The effectiveness of a nonvegetated lab-scale subsurface flow constructed wetland for wastewater treatment had been evaluated with the feed ammonium concentration of approximately 20-40 mg of NH4(+)-N L(-1) and a hydraulic retention time of approximately 10 d. The present system had a nitrification zone plus a sulfur/limestone (S/L) autotrophic denitrification zone followed by an anaerobic poli...

P25 film, prepared by a facile dip-coating method without any binder, was further developed in a recirculating reactor for quinoline removal from synthetic wastewater. Macroporous foam Ni, which has an open three-dimensional network structure, was utilized as a substrate to make good use of UV rays. Field emission scanning electron microscopy and X-ray diffraction analysis showed that the coate...

An activated sludge aeration basin (20 cm i.d., 140 cm height) equipped with either a coarse air diffuser (a plastic pipe perforated with 56 orifices of 2 mm in diameter) or a fine diffuser (porous plastic type with 100-micrometer pores) was utilized to treat an air-borne hydrophobic VOC (toluene, 700-800 mg/m). The purposes of this study were to test the influences of both MLSS and diffuser ty...

The objective of this study was to assess the role of cyclic aeration, vegetation, and temperature on nitrogen removal by subsurface-flow engineered wetlands. Aeration was shown to enhance total nitrogen and ammonia removal and to enhance removal of carbonaceous biochemical oxygen demand, chemical oxygen demand, and phosphorus. Effluent ammonia and total nitrogen concentrations were significant...

The performance of acetic acid-supported pH-heterogenized heterotrophic denitrification (HD) facilitated with ferrous sulfide-based autotrophic denitrification (AD) was investigated in upflow activated carbon-packed column reactors for reliable removal of highly elevated nitrate (42 mg NO(3)-Nl(-1)) in drinking water. The use of acetic acid as substrate provided sufficient internal carbon dioxi...