Bioaugmentation of the green alga to enhance biogas production in an anaerobic hollow-fiber membrane bioreactor.

ABSTRACT

Anaerobic membrane reactors (AnMBRs) offer an alternative wastewater treatment system, presenting both reclamation of value through biogas production, and efficient treatment of recalcitrant contaminants such as antibiotics from wastewater. The effects of bioaugmentation with the green alga Haematococcus pluvialis on anaerobic treatment of pharmaceutical wastewaters, alleviating membrane biofouling, biogas production and impact on the indigenous microbial communities were evaluated using AnMBRs. The outputs of the bioreactor experiments revealed that bioaugmentation strategies with the green alga increased removal of chemical oxygen demand by 12% and delayed membrane fouling by 25% and increased biogas production by 40%. Furthermore, bioaugmentation with the green alga led to a significant change in relative abundance of archaea and the main methanogenesis pathway shifted from Methanothermobacter to Methanosaeta, accompanied by their respective syntrophic bacteria.