Coupling Fe3O4 and micro-hydrogen for enhancing the anaerobic bio-conversion of phenol: Methanogenesis pathway and interspecies electron transfer

Chunhua He; Qilong Jin; Xue He; Hailing Liu; Weihua Li; Jian Huang; Fazhi Xie; Xianhuai Huang; Wei Wang

doi:10.1016/j.envres.2024.120125

Coupling Fe₃O₄ and micro-hydrogen for enhancing the anaerobic bio-conversion of phenol: Methanogenesis pathway and interspecies electron transfer

Environ Res. 2024 Oct 10;263(Pt 2):120125. doi: 10.1016/j.envres.2024.120125. Online ahead of print.

Authors

Chunhua He¹, Qilong Jin², Xue He³, Hailing Liu⁴, Weihua Li², Jian Huang⁵, Fazhi Xie⁵, Xianhuai Huang⁵, Wei Wang⁶

Affiliations

¹ Department of Municipal Engineering, School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230009, China; Anhui Institute of Ecological Civilization Research, Hefei, 230009, China. Electronic address: hech5828@126.com.
² Department of Municipal Engineering, School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230009, China.
³ Anhui Provincial Key Laboratory of Industrial Wastewater and Environmental Treatment, East China Engineering Science and Technology Co., Ltd., Hefei, 230022, China.
⁴ Anhui Institute of Ecological Civilization Research, Hefei, 230009, China.
⁵ Department of Municipal Engineering, School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230009, China; Anhui Institute of Ecological Civilization Research, Hefei, 230009, China.
⁶ Department of Municipal Engineering, School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China. Electronic address: dwhit@126.com.

PMID: 39395556
DOI: 10.1016/j.envres.2024.120125

Abstract

Low anaerobic biological conversion rate is a challenge in the anaerobic biological treatment of phenol wastewater. The dominant syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway is expected to solve the problem. However, there are raw studies on artificially simulating a dominant SAO-HM pathway for enhancing the anaerobic bio-conversion of phenol. In this study, Fe₃O₄ and micro-hydrogen (Fe₃O₄/H₂) was used to strengthen the anaerobic bio-conversion of phenol by simulating the dominant SAO-HM pathway. The results suggested Fe₃O₄ and H₂ had a coupling promotion on the anaerobic bio-conversion of phenol and Fe₃O₄/H₂ increased the relative abundance of Syntrophus (29.35%), Syntrophorhabdu (3.27%), Clostridium (3.01%) and Methanobacterium (65.74%), indicating Fe₃O₄/H₂ formed a dominant SAO-HM pathway. However, Fe₃O₄/H₂ obviously reduced the conductivity of sludge, the extracellular protein and the functional gens pilA, pilB and OmcS, implying direct interspecies electron transfer (DIET) generated by Fe₃O₄ was interfered by micro hydrogen in extracellular electron transport process which reduced the efficiency of extracellular electron transport. This study remind that extracellular electron transport cannot be ignored in the dominate SAO-HM pathway for the anaerobic bio-conversion of phenol.

Keywords: Anaerobic digestion; Direct interspecies electron transfer; Fe(3)O(4); Micro-hydrogen; Syntrophic acetate oxidation and hydrogenotrophic methanogenesis.