Comparison of air-cathode single chamber and double chamber Microbial fuel cells (MFCs) for sulfide-containing wastewater treatment was carried out. It was found that sulfide containing wastewater could be treated based on MFC technology with energy recovery. The maximum open circuit voltage of 897.2 mV and 821.7 mV, maximum power density of 340.0 mW/m ² and 273.8 mW/m ² , and the coulombic efficiency (CE) of 5.6% and 10.7% were realized in the single chamber and double chamber MFCs, respectively, with influent sulfide 100 mg/L and glucose 812 mg/L. Single chamber MFCs had higher performance in electricity output, but double chamber ones had a higher CE. After 72 hours operation of the single chamber MFCs, sulfide and TOC removal efficiencies reached 75.4% and 17.8%, respectively. Results indicate the feasibility of sulfide removal in MFCs and the cathode resistance is recognized as the main limiting factor in the reported system.

A sludge population optimization strategy aims to select the ammonia oxidation bacteria (AOB) by using sodium chloride (NaCl) as a selective inhibitor to nitrite oxidation bacteria (NOB) is applied in biological nitrogen removal process during municipal wastewater treatment using a sequencing batch reactor( SBR) . Different salinity tests contributed to the best inhibition salinity chosen were applied. In order to optimize nitrifying microbial communities to get steady nitrite pathway, 7.6g/ L salinity and 4 month salt inhibition period were applied. FISH analysis indicated that AOB ( Nitrosospira) became the dominant nitrifying bacteria and NOB ( Nitrobacter) had been washed out of the activated sludge. An understanding of salt inhibition mechanism on NOB is also discussed.