Characteristics of a Heterotrophic Nitrifier Consortium and Its Application in Coking Wastewater

FG-06 is a microbial consortium screened from activated sludge of coking wastewater treatment plant, which has excellent heterotrophic nitrification-aerobic denitrification ability. The aim of the study is to evaluate the possible factors affecting its heterotrophic nitrification performance and the feasibility of its application in the treatment of coking wastewater in a sequencing batch reactor (SBR). Results indicate the consortium could grow and effectively remove ammonium when the salt concentration was below 50 g/L. In the range of pH 5.0–10.0, more than 97% NH 4 + -N was removed by the consortium. Adding 1000 mg/L phenol in the basal medium (BM) had no significant effect on its nitrification ability. However, when phenol was used as the sole carbon source, the removal efficiency of phenol and ammonium decreased with the increase of phenol concentration in the case of 1% inoculum dose, which was improved by increasing the inoculum size. The removal efficiency of phenol, NH 4 + -N and COD reached 99.63%, 98.41%, and 83.69% when 3% of the consortium was inoculated in actual coking wastewater in the batch test. Bioaugmentation experiment shows that the consortium could effectively improve the simultaneous removal performance of carbon and ammonium in the SBR. Graphical Abstract