Pretreatment of sludge with sodium iron chlorophyllin-H₂O₂ for enhanced biogas production during anaerobic digestion

TY - JOUR

T1 - Pretreatment of sludge with sodium iron chlorophyllin-H2O2 for enhanced biogas production during anaerobic digestion

AU - Li, Zhen

AU - Chen, Shuo

AU - Liu, Bingchuan

AU - Yang, Jiakuan

AU - Liang, Sha

AU - Xiao, Keke

AU - Hu, Jingping

AU - Hou, Huijie

N1 - Publisher Copyright: © 2021

PY - 2022/3

Y1 - 2022/3

N2 - This study investigated a novel sodium iron chlorophyllin-H2O2 (SIC–H2O2) sludge pretreatment strategy before anaerobic digestion to enhance methane production. The efficiencies and mechanism of the proposed strategy to enhance sludge biodegradability were explored. The SIC–H2O2 pretreatment could enhance the oxidation performance for sludge floc disintegration to dissociate TB-EPS into S-EPS increased SCOD to 521.38 mg/L. The increase of solubilization and release of EPS with the pretreatment facilitate the biogas production at 702 L kg−1 VS, which was 3-folds of the control and significantly higher than other pretreatments. The result of excitation–emission matrix and parallel factor (EEM-PARAFAC) analysis showed that the SIC–H2O2 pretreatment enhanced the dissociation of TB-EPS fractions, especially the protein-like and soluble microbial by-product-like substances. Electron paramagnetic resonance (EPR) results provided evidence for homolytic catalysis H2O2 for the generation [rad]OH and the production of high-valent (Por)FeIV(O) intermediates. Synergistic effects of reactive oxygen species ([rad]OH, H2O2 and [Formula presented]/HO2) and (Por)FeIV(O) enhanced the EPS disintegration during SIC–H2O2 pretreatment. The mixed-acid type fermentation provided continuous VFAs supply under the enrichment of Chloroflexi and Actinobacteria and multiplication Methanosaeta also promoted methane production. This research provides a feasible pretreatment strategy increase sludge biodegradability and enhance biogas production in the anaerobic digestion process.

AB - This study investigated a novel sodium iron chlorophyllin-H2O2 (SIC–H2O2) sludge pretreatment strategy before anaerobic digestion to enhance methane production. The efficiencies and mechanism of the proposed strategy to enhance sludge biodegradability were explored. The SIC–H2O2 pretreatment could enhance the oxidation performance for sludge floc disintegration to dissociate TB-EPS into S-EPS increased SCOD to 521.38 mg/L. The increase of solubilization and release of EPS with the pretreatment facilitate the biogas production at 702 L kg−1 VS, which was 3-folds of the control and significantly higher than other pretreatments. The result of excitation–emission matrix and parallel factor (EEM-PARAFAC) analysis showed that the SIC–H2O2 pretreatment enhanced the dissociation of TB-EPS fractions, especially the protein-like and soluble microbial by-product-like substances. Electron paramagnetic resonance (EPR) results provided evidence for homolytic catalysis H2O2 for the generation [rad]OH and the production of high-valent (Por)FeIV(O) intermediates. Synergistic effects of reactive oxygen species ([rad]OH, H2O2 and [Formula presented]/HO2) and (Por)FeIV(O) enhanced the EPS disintegration during SIC–H2O2 pretreatment. The mixed-acid type fermentation provided continuous VFAs supply under the enrichment of Chloroflexi and Actinobacteria and multiplication Methanosaeta also promoted methane production. This research provides a feasible pretreatment strategy increase sludge biodegradability and enhance biogas production in the anaerobic digestion process.

KW - Advanced oxidation

KW - Anaerobic digestion

KW - Methane

KW - Sodium iron chlorophyllin

KW - Waste activated sludge

UR - http://www.scopus.com/inward/record.url?scp=85118565320&partnerID=8YFLogxK

U2 - 10.1016/j.envres.2021.112223

DO - 10.1016/j.envres.2021.112223

M3 - 文章

C2 - 34688644

AN - SCOPUS:85118565320

SN - 0013-9351

VL - 204

JO - Environmental Research

JF - Environmental Research

M1 - 112223

ER -