Effect of biochar on immobilization remediation of Cd⁃contaminated soil and environmental quality

• Published in: Environmental research 2022-03, Vol.204 (Pt A), p.111840-111840, Article 111840
• Main Authors: Tang, Bo, Xu, Haopu, Song, Fengmin, Ge, Hongguang, Chen, Li, Yue, Siyu, Yang, Wushan
• Format: Article
• Language: English
• Subjects: Cadmium - analysis; Cd-contaminated soil; Charcoal; Environmental Restoration and Remediation; PEI-Modified biochar; Soil; Soil aggregates; Soil enzymes; Soil Pollutants - analysis; Soil remediation
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2021.111840

Field experiments were conducted to explore the remediation effects of ordinary biochar and PEI-modified biochar on the Cd-contaminated yellow brown soil, and the improvement of soil environment quality in southern Shaanxi province, so as to provide theoretical basis and technical support for in-situ remediation of Cd-contaminated soil in southern Shaanxi province. Biochar applied in soil could increase the soil pH value, EC, ECEC, and SOC, and improve the soil physical and chemical properties to a certain extent. Biochar in soil could change the chemical form of Cd in soil, effectively passivate Cd in soil and reduce its bio-availability. Biochar could enhance the activities of catalase, urease, alkaline phosphatase and sucrase in soil to different degrees, and the four soil enzymes could be used as indicators of passivation effects of soil Cd by biochar. With biochar treatment, soil aggregates MWD and GMD increased to different degrees, so biochar could enhance soil stability. The biochar could decrease the content of Cd in different parts of wheat, the content of Cd in wheat grains had a highly significant positive correlation with the available content of Cd in soil, and highly significant or significant negative correlations with pH, SOC, EC, ECEC, and the activities of phosphatase, urease and sucrase in soil. Compared with ordinary biochar, the passivation effect of PEI-modified biochar on Cd was more significant. The results of the study indicated that ordinary biochar and PEI-modified biochar could passivate the Cd in soil, and remediate Cd-contaminated soil, and improve the soil environmental quality effectively, compared with ordinary biochar, the PEI-modified biochar produced batter. •Explore remediation effects of ordinary and Polyethyleneimine PEI-modified biochar.•Provide theoretical & technical support for in-situ remediation of Cd-contaminated soil.•Results indicated that ordinary biochar & PEI-modified biochar could passivate Cd in soil & remediate Cd-contaminated soil.•Study results improve the soil environmental quality effectively.