Crawfish shell- and Chinese banyan branch-derived biochars reduced phytoavailability of As and Pb and altered community composition of bacteria in a contaminated arable soil

• Published in: The Science of the total environment Vol. 865; p. 161284
• Main Authors: Gu, Shaoru, Yang, Xing, Chen, Hanbo, Jeyakumar, Paramsothy, Chen, Junhui, Wang, Hailong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.03.2023
• Subjects: Animals; Arsenic - analysis; Astacoidea; Bacteria; Carbon; Charcoal; Ficus; Heavy metal; High-throughput sequencing; Lead - analysis; Microbial community; Soil; Soil Pollutants - analysis; Soil remediation; Waste management; Waste management; Soil remediation; High-throughput sequencing; Microbial community; Heavy metal
• DOI: 10.1016/j.scitotenv.2022.161284
• ISSN: 0048-9697

Globally, soil contamination with arsenic (As) and lead (Pb) has become a severe environmental issue. Herein, a pot experiment was conducted using pak choi (Brassica chinensis L.) to investigate the effects of biochars derived from crawfish (Procambarus clarkia) shells (CSB) and Chinese banyan (Ficus microcarpa) branches (CBB) on the phytoavailability of As and Pb, and bacterial community composition in soils. Our results showed that the application of CSB and CBB decreased the concentrations of DTPA-extractable Pb in soils ranging from 26.8 % to 28.8 %, whereas CSB increased the concentration of NH4H2PO4-extractable As in soils, compared to the control. Application of both biochars reduced the uptake of As and Pb in the edible part of pak choi. In addition, application of CBB significantly (P < 0.05) increased the activities of α-glucosidase, β-glucosidase, cellobiohydrolase, and acid phosphomonoesterase by 55.0 %, 54.4 %, 195.1 %, and 76.7 %, respectively, compared to the control. High-throughput sequencing analysis revealed that the predominant bacteria at the phyla level in both biochar-treated soils were Firmicutes, Proteobacteria, and Actinobacteriota. Redundancy and correlation analyses showed that the changes in bacterial community composition could be related to soil organic carbon content, As availability, and nutrient availability in soils. Overall, the Chinese banyan branch biochar was more suitable than the crawfish shell biochar as a potential amendment for the remediation of soils co-contaminated with As and Pb. [Display omitted] •Application of crawfish shell and Chinese bayan biochars immobilized Pb in soil.•Application of both biochars reduced As and Pb uptake by pak choi plants.•Chinese banyan biochar was more effective on increasing soil enzyme activities.•Biochar-induced changes in As stress altered bacterial community structure in soil.