Iron foam coupled hydrolysis acidification for trichloroacetaldehyde treatment: strengthening characteristics and mechanism.

Abstract This research studied transformative characteristics and enhanced mechanism of trichloroacetaldehyde (TCAL), one of chlorinated acetaldehydes (CAAs), by coupled-type iron foam enhanced hydrolysis acidification (HA) reactor. Main results were given that better dechlorination and aldehyde removal were achieved at this process than coupled-type iron foam enhanced HA, alone iron foam and HA reactor. The reasons were due to better strengthening effects of iron foam and HA, iron foam reduced TCAL toxicity to microbes caused an improvement of microbial activity, therefore, volatile fatty acids (VFAs) content and acetate acid (Ac) ratio were increased compared with HA. Moreover, it promoted the enrichment of Actinobacteriota and Firmicutes, and more extracellular polymeric substance (EPS) and enzymes enhanced dechlorination and aldehyde removal. Certainly, microbes reduced iron foam passivation and facilitated its oxidation further improved the strengthening effect.