Influence of biochar on the remediation of cadmium-contaminated soil in an Eisenia fetida–Solanum nigrum system

Biochar, plants, and earthworms have good remediation effects on cadmium (Cd)-contaminated soils. However, few studies have combined all three technologies to explore the treatment of Cd-contaminated soils. This study investigated the effect of corn straw biochar addition (1% and 5% mass ratios) on...

Full description

Saved in:

Bibliographic Details
Published in:	Environmental chemistry and ecotoxicology Vol. 6; pp. 132 - 143
Main Authors:	Luo, QingRui, Liu, Chang’e, Zhao, YiQiao, Zhang, WeiLan, Chen, JinQuan, Pan, Ying, Duan, ChangQun
Format:	Journal Article
Language:	English
Published:	Elsevier B.V 2024 KeAi Communications Co., Ltd
Subjects:	Accumulation and translocation Co-remediation Eisenia fetida Hyperaccumulator plant Soil amendments Accumulation and translocation Hyperaccumulator plant Eisenia fetida Soil amendments Co-remediation
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Biochar, plants, and earthworms have good remediation effects on cadmium (Cd)-contaminated soils. However, few studies have combined all three technologies to explore the treatment of Cd-contaminated soils. This study investigated the effect of corn straw biochar addition (1% and 5% mass ratios) on soil Cd treatment in an Eisenia fetida–Solanum nigrum system. The addition of corn straw biochar increased soil pH, total nitrogen (TN), total phosphorus (TP), and soil organic carbon (SOC); adding 5% (w/w) biochar under Cd stress resulted in significant increases (P < 0.05) of soil pH, TN, TP, and SOC. Adding 5% (w/w) biochar under Cd stress increased Cd enrichment by E. fetida and S. nigrum and significantly reduced the soil total and available Cd contents (P < 0.05). The addition of biochar increased the metallothionein content of E. fetida, which functions to resist Cd stress in high-Cd environments (P < 0.05); with the addition of 5% (w/w) biochar, the metallothionein content was 1.55 times higher than in the 1% (w/w) biochar treatment, at 23.78 ng L−1. Adding 5% (w/w) biochar significantly increased the Cd enrichment coefficient and transfer coefficient values of S. nigrum under high-Cd stress (P < 0.05), reaching 7.37 and 1.89, respectively. Adding 5% (w/w) biochar significantly reduced the exchangeable and acid-soluble fraction of Cd, increased the oxidizable fraction, reduced Cd bioavailability, and mitigated physiological damage (P < 0.05). The present study demonstrated that adding biochar to the E. fetida–S. nigrum system could effectively reduce the soil Cd pollution level, providing a new method and scientific guidance for the remediation of heavy metal-polluted soil. [Display omitted] •Adding biochar to the Eisenia fetida–S. nigrum system can improve soil physicochemical properties while reducing the bioavailability of Cd.•A 5%(w/w) biochar can effectively improve Cd's TF and BCF in S. nigrum under high cadmium conditions.•At high Cd concentrations, adding 5%(w/w) biochar can promote the secretion of MT by earthworms to accumulate more Cd.
ISSN:	2590-1826 2590-1826
DOI:	10.1016/j.enceco.2024.04.003