Enhanced biodegradation of coal gasification wastewater (CGW) by a novel integration of powdered activated carbon treatment (PACT) coupled with wet air regeneration (WAR)

Abstract

This study illustrated the advanced degradation of coal gasification wastewater (CGW) by powdered activated carbon treatment (PACT) coupled with wet air regeneration (WAR). The results demonstrated that the PACT-WAR process achieved high efficiencies on the removal of COD (92.58%), Tph (96.56%), NH4+-N (99.52%), and TN (71.52%). The PACT process was more favorable to improving the structural stability of activated sludge (AS) and the biodiversity of specific functional microbial communities. Among them, the relative abundance of Sphingopyxis, Flavobacterium, Nitrosomonas and Terrimonas was enriched to facilitate the degradation of phenolic and nitrogen compounds. More importantly, the regeneration efficiency of spent PAC was 83.33% by the WAR process, which would effectively reduce the addition of fresh PAC. The regeneration solution displayed better denitrification capacity as the additional carbon source. Therefore, the PACT-WAR process was an excellent practical process for enhancing CGW treatment.