Simultaneous removal of volatile organic compounds (VOCs) and nitrogen: batch test

A batch test was conducted to investigate the effect of the chemical oxygen demand, (COD)/N ratio, nitrate, nitrite and temperature, on the microbial degradation of volatile organic compounds (VOCs), and the denitrification capability using VOCs-acclimatized and un-acclimatized cultures. The nitrite reduction rates differed with each reactor, as follows: 15.418 NO2-N mg MLVSS g(-1) h(-1) in the benzene and methanol (BM) reactor, 27.463 NO2-N mg MLVSS g(-1) h(-1) in the toluene and methanol (TM) reactor and 44.358 NO2-N mg MLVSS g(-1) h(-1) in the methanol (M) reactor. According to the COD/N ratio, the nitrate reduction rates of the BM and TM reactors acclimatized by VOCs changed in the ranges of 29.4-33.41 NO3-N mg MLVSS g(-1) day(-1) and 56.4-65.9 NO3-N mg MLVSS g(-1) day(-1), respectively. Thus, benzene was not effectively utilized as a carbon source. Conversely, toluene was utilized as a carbon source by the denitrifiers under substrate limited conditions. The specific denitrification rates were also greater in the TM reactor than those for both the substrate limited and unlimited conditions in the BM reactor.