Disinfectant sodium dichloroisocyanurate synergistically strengthened sludge acidogenic process and pathogens inactivation: Targeted upregulation of functional microorganisms and metabolic traits via self-adaptation

Wenxuan Huang; Yi Li; Feng Wang; Leiyu Feng; Dongbo Wang; Yingqun Ma; Yang Wu; Jingyang Luo

doi:10.1016/j.watres.2023.120787

Disinfectant sodium dichloroisocyanurate synergistically strengthened sludge acidogenic process and pathogens inactivation: Targeted upregulation of functional microorganisms and metabolic traits via self-adaptation

Water Res. 2023 Dec 1:247:120787. doi: 10.1016/j.watres.2023.120787. Epub 2023 Oct 27.

Authors

Wenxuan Huang¹, Yi Li¹, Feng Wang¹, Leiyu Feng², Dongbo Wang³, Yingqun Ma⁴, Yang Wu⁵, Jingyang Luo⁶

Affiliations

¹ Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
² State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
³ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
⁴ Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China.
⁵ State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: wuyang1026@tongji.edu.cn.
⁶ Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China. Electronic address: luojy2016@hhu.edu.cn.

PMID: 37918196
DOI: 10.1016/j.watres.2023.120787

Abstract

Harmless and resourceful treatment of waste activated sludge (WAS) have been the crucial goal for building environmental-friendly and sustainable society, while the synergistic realization approach is currently limited. This work skillfully utilized the disinfectant sodium dichloroisocyanurate (NaDCC) to simultaneously achieve the pathogenic potential inactivation (decreased by 60.1 %) and efficient volatile fatty acids (VFAs) recovery (increased by 221.9 %) during WAS anaerobic fermentation in rather cost-effective way (Chemicals costs:0.4 USD/kg VFAs versus products benefits: 2.68 USD/kg chemical). Mechanistic analysis revealed that the C=O and NCl bonds in NaDCC could spontaneously absorb sludge (binding energy -4.9 kJ/mol), and then caused the sludge disintegration and organic substrates release for microbial utilization due to the oxidizability of NaDCC. The disruption of sludge structure along with the increase of bioavailable fermentation substrates contributed to the selectively regulation of microbial community via enriching VFAs-forming microorganisms (e.g., Pseudomonas and Streptomyces) and reducing VFAs-consuming microorganisms, especially aceticlastic methanogens (e.g., Methanothrix and Methanospirillum). Correspondingly, the metabolic functions of membrane transport, substrate metabolism, pyruvate metabolism, and fatty acid biosynthesis locating in the central pathway of VFAs production were all upregulated while the methanogenic step was inhibited (especially acetate-type methanogenic pathway). Further exploration unveiled that for those enriched functional anaerobes were capable to activate the self-adaptive systems of DNA replication, SOS response, oxidative stress defense, efflux pump, and energy metabolism to counteract the unfavorable NaDCC stress and maintain high microbial activities for efficient VFAs yields. This study would provide a novel strategy for synergistic realization of harmless and resourceful treatment of WAS, and identify the interrelations between microbial metabolic regulations and adaptive responses.

Keywords: Anaerobic fermentation; Microbial adaptation; Microbial competition; Sodium dichloroisocyanurate (NaDCC); Waste activated sludge (WAS).

MeSH terms

Anaerobiosis
Fatty Acids, Volatile / metabolism
Fermentation
Hydrogen-Ion Concentration
Sewage* / chemistry
Triazines*
Up-Regulation

Substances

Sewage
troclosene
Triazines
Fatty Acids, Volatile