Characterization of trace metal impact on organic acid metabolism and functional microbial community in treating dairy processing wastewater with thermophilic anaerobic membrane bioreactor.

The anaerobic digestion (AD) of dairy processing wastewater (DPW) to produce bioenergy is considered promising but also associated with the possibility of an unbalanced organic matter and trace metal (TM) content. In this study, the TM content and its impact on AD were determined in an anaerobic membrane bioreactor operated to treat DPW. The results indicated that a deficiency in TMs resulted in the slow deterioration of the process, reducing biogas production, disrupting the buffer system, and the massive accumulation of organic acid.

Methanogenic treatment of dairy product wastewater by thermophilic anaerobic membrane bioreactor: Ammonia inhibition and microbial community.

Dairy product wastewater contains high-strength organic matter suitable for anaerobic treatment, but excessive protein degradation may lead to an ammonia inhibition problem. This work studied protein-rich dairy product wastewater treatment in the anaerobic membrane bioreactor. The results showed that a temporary self-detoxification phase of ammonia inhibition from the change of pH buffer system was vital for rapid reactor recovery by substrate dilution.