Recent studies have shown that vapor-phase bioreactors containing the fungus Exophiala lecanii-corni can remove nitric oxide (NO) and volatile organic compounds efficiently from waste gas streams. However, when NH4 accumulates in the bioreactor, the NO removal efficiency abruptly drops to 20 %. To achieve high NOx removals in the bioreactors, low NH4 levels must be maintained, or a different ni...

The present lab-scale research reveals the potential of implementation of an oxygen-limited autotrophic nitrification-denitrification (OLAND) system with normal nitrifying sludge as the biocatalyst for the removal of nitrogen from nitrogen-rich wastewater in one step. In a sequential batch reactor, synthetic wastewater containing 1 g of NH4+-N liter-1 and minerals was treated. Oxygen supply to ...

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 μm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days....

Step-feeding strategies have been extensively studied and comprehensively analyzed in this study for a four-stage alum sludge-based tidal flow constructed wetlands (AlS-TFCWs) system. Enhanced total nitrogen removal of 83% is achieved under high nitrogen loading rate of 19.1 g N/m(2)d. The key issues towards the success of a significant nitrogen removal in step-feeding TFCWs are the bed resting...

Ammonium stripping has gained increasing interest for nitrogen recovery in anaerobically digested effluents. However, the stripped effluents often still do not meet discharge standards, having high pH and residual pollutants. Constructed wetlands (CWs) are an easy to operate ecosystem and have a long history of application in treatment of wastewaters with extreme pH, such as acid mine drainage....