Effect of semiconductor materials on anaerobic methanogenesis of terephthalic acid: Promotion and inhibition mechanisms

The treatment of purified terephthalic acid wastewaters via anaerobic methods poses a significant challenge due to the slow degradation rate and extended reaction time required for the most recalcitrant terephthalic acid (TA). To address this challenge, this study investigated the efficacy of various semiconductors in promoting TA degradation and determined their respective functional roles. Results showed that the addition of g-C 3 N 4 increased methane production by 28.38%, indicating its potential as a replacement for TiO 2 in TA degradation. The improvement was attributed to the intensified direct interspecies electron transfer (DIET) process, facilitated by microorganisms that directly utilize conductive TiO 2 /g-C 3 N 4 as intermediaries to accelerate the electron transfer rate. The unfavorable methanogenesis performances of CeO 2 and Fe 2 O 3 were accredited to agglomeration phenomena and toxic effects. This study provides insights into the roles of exogenous materials in promoting or limiting the DIET process, and offers an environmentally friendly and highly-effective strategy for treating industrial purified-terephthalic acid wastewater.