Long-term Cd remediation mechanisms and potential risks in soil with biochar application under dry-wet cycling at different soil moisture levels

IF 5.9 1区 农林科学 Q1 AGRONOMY
Shuang Huang, Zhuowen Meng, Jingwei Wu, Lei Xin, Qin Zhao
{"title":"Long-term Cd remediation mechanisms and potential risks in soil with biochar application under dry-wet cycling at different soil moisture levels","authors":"Shuang Huang, Zhuowen Meng, Jingwei Wu, Lei Xin, Qin Zhao","doi":"10.1016/j.agwat.2024.109212","DOIUrl":null,"url":null,"abstract":"Dry-wet cycling and soil moisture are key factors affecting cadmium (Cd) remediation in soils by biochar; however, their long-term effects on the transport of Cd between soil and biochar, Cd fraction distribution, and Cd potential risks are still unclear. To reveal the long-term Cd remediation mechanisms and potential risks in soil under biochar treatment, 180 days of artificial dry-wet cycling was conducted at four soil moisture levels (40 % θ<ce:inf loc=\"post\">s</ce:inf>, 60 % θ<ce:inf loc=\"post\">s</ce:inf>, 80 % θ<ce:inf loc=\"post\">s</ce:inf>, and 100 % θ<ce:inf loc=\"post\">s</ce:inf>; θ<ce:inf loc=\"post\">s</ce:inf>, saturated water content, W/W) based on local meteorological data to simulate 30 years of natural dry-wet processes. The results showed that Cd adsorbed by biochar in soils during long-term ageing first underwent rapid adsorption (over 0–5 years of simulated ageing), then equilibrium stabilization (over 5–20 years of simulated ageing), and finally slight re-released (over 20–30 years of simulated ageing). Compared with the total Cd adsorbed by biochar in the 20th year of simulated ageing, Cd adsorption by biochar accounted for 85.28 %, 14.72 %, and −3.22 % during 0–5, 5–20, and 20–30 years of simulated ageing, respectively, in the soil at 100 % θ<ce:inf loc=\"post\">s</ce:inf>. Similarly, the available Cd slightly increased in 20–30 years of simulated ageing. The greater the soil moisture was, the more effective the adsorption and immobilization of Cd by biochar. At the 20th year of simulated ageing, the Cd adsorption by biochar at 100 % θ<ce:inf loc=\"post\">s</ce:inf> was 1.51 times that at 40 % θ<ce:inf loc=\"post\">s</ce:inf>; the available Cd in the soil with biochar at 100 % θ<ce:inf loc=\"post\">s</ce:inf> was 0.91 times that at 40 % θ<ce:inf loc=\"post\">s</ce:inf>. The contribution of nonmineral components in biochar to Cd adsorption was greater in 0–1 years of the simulation, but the contribution of mineral components dominated and slightly decreased during 1–30 years of the simulation. This study highlighted that biochar was fairly effective in the long-term remediation of Cd in contaminated soils, but there was some risk of Cd activation in the later stages due to the ageing of biochar. Agricultural irrigation management has a significant effect on the long-term effectiveness of biochar remediation of Cd pollution. To prevent Cd reactivation, a high field moisture level is recommended, and excessive dry-wet cycling should be avoided through water management practices such as frequent irrigation with small amounts of water.","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"1 1","pages":""},"PeriodicalIF":5.9000,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Agricultural Water Management","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1016/j.agwat.2024.109212","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRONOMY","Score":null,"Total":0}
引用次数: 0

Abstract

Dry-wet cycling and soil moisture are key factors affecting cadmium (Cd) remediation in soils by biochar; however, their long-term effects on the transport of Cd between soil and biochar, Cd fraction distribution, and Cd potential risks are still unclear. To reveal the long-term Cd remediation mechanisms and potential risks in soil under biochar treatment, 180 days of artificial dry-wet cycling was conducted at four soil moisture levels (40 % θs, 60 % θs, 80 % θs, and 100 % θs; θs, saturated water content, W/W) based on local meteorological data to simulate 30 years of natural dry-wet processes. The results showed that Cd adsorbed by biochar in soils during long-term ageing first underwent rapid adsorption (over 0–5 years of simulated ageing), then equilibrium stabilization (over 5–20 years of simulated ageing), and finally slight re-released (over 20–30 years of simulated ageing). Compared with the total Cd adsorbed by biochar in the 20th year of simulated ageing, Cd adsorption by biochar accounted for 85.28 %, 14.72 %, and −3.22 % during 0–5, 5–20, and 20–30 years of simulated ageing, respectively, in the soil at 100 % θs. Similarly, the available Cd slightly increased in 20–30 years of simulated ageing. The greater the soil moisture was, the more effective the adsorption and immobilization of Cd by biochar. At the 20th year of simulated ageing, the Cd adsorption by biochar at 100 % θs was 1.51 times that at 40 % θs; the available Cd in the soil with biochar at 100 % θs was 0.91 times that at 40 % θs. The contribution of nonmineral components in biochar to Cd adsorption was greater in 0–1 years of the simulation, but the contribution of mineral components dominated and slightly decreased during 1–30 years of the simulation. This study highlighted that biochar was fairly effective in the long-term remediation of Cd in contaminated soils, but there was some risk of Cd activation in the later stages due to the ageing of biochar. Agricultural irrigation management has a significant effect on the long-term effectiveness of biochar remediation of Cd pollution. To prevent Cd reactivation, a high field moisture level is recommended, and excessive dry-wet cycling should be avoided through water management practices such as frequent irrigation with small amounts of water.
求助全文
约1分钟内获得全文 求助全文
来源期刊
Agricultural Water Management
Agricultural Water Management 农林科学-农艺学
CiteScore
12.10
自引率
14.90%
发文量
648
审稿时长
4.9 months
期刊介绍: Agricultural Water Management publishes papers of international significance relating to the science, economics, and policy of agricultural water management. In all cases, manuscripts must address implications and provide insight regarding agricultural water management.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信