Roles of different humin and heavy-metal resistant bacteria from composting on heavy metal removal

• Published in: Bioresource technology Vol. 296; p. 122375
• Main Authors: Wei, Yuquan, Zhao, Yue, Zhao, Xinyu, Gao, Xintong, Zheng, Yansi, Zuo, Huiduan, Wei, Zimin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2020
• Subjects: Bacteria; bacterial communities; binding capacity; Biosorption; cadmium; chromium; Composting; composts; copper; Heavy metal ions; heavy metals; Heavy-metal resistant bacteria; Humic Substances; humification; Humin; lead; metal tolerance; Metals, Heavy; nickel; pollution; pollution control; Role; Soil; structural equation modeling; zinc; Humin; Heavy metal ions; Composting; Heavy-metal resistant bacteria; Biosorption
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2019.122375

[Display omitted] •Composting humin with higher humification had better sorption of heavy metals.•Heavy metal resistant bacteria in composting could bind more metal ions than humin.•Biomass and humification are the key factors for the biosorption of heavy metals.•Humin improved heavy metals biosorption by affecting bacterial diversity and biomass.•Combining MPHM with heavy-metal resistant bacteria is fit for heavy metal removal. This study aims to assess the roles of different humin and heavy-metal resistant bacterial community from composting on heavy metal removal. The results showed that the concentration of Cu2+, Zn2+, Ni2+, Pb2+, Cr3+ and Cd2+ decreased with adding the compost-derived humin, but the removal rates were relatively low (<30% on average). The heavy metal resistant bacteria from composting have better metal binding capacities than humin, and the combined addition of humin and bacteria could further stimulate the biosorption of heavy metals with 60–80% removal of metals and improve the diversity and biomass of bacterial community. There was obviously increased synergy between the humin from maturity phase and bacteria for metal biosorption (“1 + 1 > 2”). Structural equation modeling showed that microbial biomass and humin humification are the key factors for the biosorption of heavy metals. Combining humin from maturity phase with heavy-metal resistant bacteria was suggested to control heavy metal pollution in composts.