In the presence of nitrogen oxides, nitrate-reducing bacteria (NRB) may use nitrate as an electron acceptor, reduce nitrate to nitrite, and finally convert nitrite to nitrogen or ammonium (NO and N2O). Studies have shown that BCX (Bio-Competitive Exclusion) is a viable , ecologically benign, and low...

Anthracene and phenanthrene belong to a group of persistent environmental contaminants called PAHs. Evaluation of the structure of two selected PAHs i.e. anthracene and phenanthrene on their resistance to destruction by UV-activated PDS was the aim of this study. The authors focused on two aspects...

A pilot-scale sequencing batch reactor (SBR) for anaerobic ammonium oxidation (anammox) of bacteria culture was used along with a batch experimental reaction device to study the effect of NO2--N concentration on the activity of anammox bacteria and the recovery of N2H4 on anammox bacteria after...

In this study, a two-stage anaerobic ammonium oxidation (anammox) system—including a partial nitritation system with a biological selector (PNBS) and a granular activated carbon-based granule anammox process (GAP) —was used for the treatment of real high-strength rare-earth ammonia wastewater (HRAW)...

Denitrifying polyphosphate accumulating organisms (DNPAOs) are very promising for simultaneous nitrogen and phosphorus removal. While during denitrification, emission of a greenhouse gas, nitrous oxide (N 2O), may occur. In this study, DNPAOs were enriched in a lab-scale reactor, and N 2O emission...

A high efficient nitrite based double-sludge system combining sequential denitrification and nitritation reactors has been developed to remove nitrogen from wastewaters containing high concentrations of ammonium. System performance was examined and also nitrous oxide (N 2O) emission was measured...

In this paper, one partial nitritation system with biological selector (PNBS) was first evaluated in treating high-strength ammonia containing wastewater. Nitrite production rate (NPR) of 8.25 kg N m -3 d -1 was achieved with influent NH4-N concentration 2000 mg l -1 and HRT 3.2 h, which is, to our...

A bench-scale biofiltration system was developed to evaluate the NOx removal efficiency under high oxygen concentration. The system had been running for 120 days and kept on a steady NOx removal rate above 80%. A stable NOx removal with an efficiency of more than 80% from the gas phase can be...

The process of nitrification in wastewater treatment is widely accepted as a two-step process. In the first step the ammonia is oxidized to nitrite, a process considered to be carried out mainly by the Nitrosomonas sp., while in the second step the Nitrobacter sp. oxidizes the nitrite to nitrate...