Enhancement of biodegrability and microbial response of activated sludge from hydrothermal pretreatment of phenolic wastewater

A novel hydrothermal pretreatment (HTP) was applied for the biochemical treatment of phenolic wastewater with high concentrations of phenolic substances.250 degrees Celsius is the reaction temperature dividing point for complete oxidation, hydrothermal gasification and amino group release of carbonaceous organics in phenolic wastewater. The combination of HTP and AO biochemical reactions was found to be effective in improving the removal of organic pollutants and nitrogenous compounds from phenolic wastewater compared to the AO biochemical process alone. The AO biochemical reaction after HTP optimized the effective substrate, metabolic activity and the abundance of functional anaerobic bacteria of the bacterial flora, which improved the conversion efficiency of the refractory substances of phenolic wastewater, and the increase of Chloraflexi colonies and functional genes associated with the phenolic degradation pathway when the HTL wastewater at 250 degrees Celsius entered the aerobic section to achieve effective phenolic removal.