Recombinant Rhodococcus erythropolis expressing HAO and AMO genes promotes nitrogen and organic matter removal efficiency in the treatment of landfill leachate

Abstract

The purpose of this study was to investigate the treatment efficacy of recombinant Rhodococcus erythropolis (RH) expressing hydroxylamine oxidase (HAO) and ammonia monooxygenase (AMO) genes (rRH‐HA) in removing nitrogen and organic matter in landfill leachate. Results demonstrated that rRH‐HA efficiently expressed HAO and AMO during the treatment of landfill leachate in aerobic system. Enhanced rRH‐HA production increased pH control and the activity and stability of activated sludge (AS); decreased carbon source addition and decreased total organic carbon (TOC), chemical oxygen demand (COD), organic matter and heavy metal concentration compared with AS system. In conclusion, data indicate that enhanced rRH‐HA production promotes pollutants removal efficiency in the treatment of landfill leachate.