Combining high pressure homogenization with free nitrous acid pretreatment to improve anaerobic digestion of sewage sludge

Mohammad Nabi; Dawen Gao; Jinsong Liang; Yajing Cai; Panyue Zhang

doi:10.1016/j.jenvman.2022.115635

Combining high pressure homogenization with free nitrous acid pretreatment to improve anaerobic digestion of sewage sludge

J Environ Manage. 2022 Sep 15:318:115635. doi: 10.1016/j.jenvman.2022.115635. Epub 2022 Jul 1.

Authors

Mohammad Nabi¹, Dawen Gao², Jinsong Liang³, Yajing Cai³, Panyue Zhang⁴

Affiliations

¹ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China; School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
² School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
³ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China.
⁴ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China. Electronic address: panyue_zhang@bjfu.edu.cn.

PMID: 35949088
DOI: 10.1016/j.jenvman.2022.115635

Abstract

Single pretreatment of sewage sludge, either physical, chemical or biological, has its own drawbacks in term of poor sanitization, energy intensity and high operational and capital cost. To tackle these drawbacks, combined high pressure homogenization (HPH) and free nitrous acid (FNA) pretreatment for sludge solubilization and further biodegradation in anaerobic digestion was investigated. Synergistic effect of combined HPH (40 MPa) and FNA (2.49 mg/L) pretreatment (HPH-FNA) for improving anaerobic digestion was evaluated, and its effect on archaeal and bacterial community structure was analyzed. Compared with single HPH and FNA pretreatments, HPH-FNA pretreatment efficiently solubilized wasted activated sludge (WAS), subsequently improved anaerobic digestion. Cumulative biogas production from sewage sludge pretreated with HPH-FNA was 154%, 108% and 284% more than that with single pretreatment of FNA, HPH and raw sludge, respectively. In addition, volumetric biogas production of combined pretreatment system (815 ml) was more than the sum from single pretreatment (710 ml). Methane content in biogas for raw sludge, FNA, HPH and HPH-FNA pretreated sludge was 45%, 51%, 55% and 65%, respectively. Illumina MiSeq sequencing analysis revealed that HPH-FNA pretreatment promoted bacterial growth of phyla Bacteroidetes, Firmicutes and Synergistetes and archaeal genera Methanospirillum and Methanosaeta. Overall, combined HPH-FNA pretreatment of sewage sludge, prior to anaerobic digestion, is an environmentally-friendly and potentially economic technology.

Keywords: Anaerobic digestion; Biogas production; HPH-FNA pretreatment; Microbial community; Sewage sludge.

MeSH terms

Anaerobiosis
Biofuels / analysis
Bioreactors
Methane / analysis
Nitrous Acid* / analysis
Sewage* / chemistry
Waste Disposal, Fluid

Substances

Biofuels
Sewage
Methane
Nitrous Acid