生态环境学报 ›› 2022, Vol. 31 ›› Issue (8): 1647-1656.DOI: 10.16258/j.cnki.1674-5906.2022.08.017

• 研究论文 • 上一篇    下一篇

新型污泥生物炭对土壤重金属Cr和Cd的修复研究

房献宝1(), 张智钧1, 赖阳晴1, 叶脉1, 刁增辉2,*()   

  1. 1.广东省环境科学研究院,广东 广州 510045
    2.仲恺农业工程学院,广东 广州 510225
  • 收稿日期:2022-06-30 出版日期:2022-08-18 发布日期:2022-10-10
  • 通讯作者: * 刁增辉(1986年生),男,教授,博士,研究方向为环境污染修复。E-mail: zenghuid86@163.com
  • 作者简介:房献宝(1982年生),男,工程师,硕士,研究方向为环境污染监测。E-mail: 99778122@qq.com
  • 基金资助:
    广东省环保专项资金项目(粤财资环[2022]18号);广东省财政厅经费资助项目(2022-GD-6);广东省普通高校重点领域专项(2020ZDZX1003);广东省重点建设学科科研能力提升项目(2021ZDJS007)

Remediation of Heavy Metals Cr and Cd in Soil by A Novel Sludge-derived Biochar

FANG Xianbao1(), ZHANG Zhijun1, LAI Yangqing1, YE Mai1, DIAO Zenghui2,*()   

  1. 1. Guangdong Provincial Academy of Environmental Sciences, Guangzhou 510045, P. R. China
    2. Zhongkai University of Agriculture and Engineering, Guangzhou 510225, P. R. China
  • Received:2022-06-30 Online:2022-08-18 Published:2022-10-10

摘要:

采取适宜的措施对土壤重金属污染进行修复是当前的研究热点。该研究采用缺氧高温热解法成功制备出一种新型污泥生物炭(SC),并用于土壤重金属铬(Cr)和镉(Cd)的修复。试验结果表明,所制备的污泥生物炭呈多孔结构且有丰富的含氧官能团和多种矿物质组分,污泥生物炭的施加不仅能有效地改善土壤的理化性质和提升土壤肥力,还能增强土壤酶活性和土壤微生物丰度。在40 d内,污泥生物炭对土壤重金属Cr和Cd的修复固定效率分别能达到69.2%和93.2%,Cr和Cd的形态是以残渣态为主。在盆栽试验中,污泥生物炭通过固定土壤重金属Cr和Cd,有效阻控Cr和Cd在青菜中各部位的积累,降低了重金属的生物可利用性。基于批实验结果和XPS分析结果,提出污泥生物炭修复土壤重金属Cr和Cd的可能反应机制,Cr的修复主要通过吸附、还原、络合和沉淀的作用,形成较稳定态的物质如Cr2O3、Cr(OH)3和FeCr2O4等,而Cd的修复主要是通过吸附和沉淀的作用形成如Cd(OH)2和CdO等稳定态物质。该研究不但为污泥生物炭在土壤重金属Cr和Cd修复提供理论基础和技术支撑,也实现了市政污泥的“以废治废”。

关键词: 污泥生物炭, 铬(Cr), 镉(Cd), 土壤修复, 污染土壤

Abstract:

The problem of heavy metal pollution in soil has attracted increasing attention, and how to take appropriate treatment to remediate is a hotspot of current research. In this study, a novel sludge-derived biochar (SC) was successfully prepared through anoxic high-temperature pyrolysis and used for the remediation of heavy metals chromium (Cr) and cadmium (Cd) in soil. The experimental results show that the SC has a porous structure with abundant oxygen-containing functional groups and various mineral components. The application of SC not only effectively improves the soil properties and enhance soil fertility, but also enhances the enzymes activities and microorganism abundance in soil. Within 40 days, the remediation efficiencies of Cr and Cd by SC could reach up to 69.2% and 93.2%, respectively, and the main form of the two metals was in residual fraction. In the pot experiment, both Cr and Cd were immobilized by SC for preventing the accumulation of them in various parts of Brassica chinensis L., leading to a decrease in the bioavailability of heavy metals. Based on the results of batch experiments and XPS analysis, the possible reaction mechanism for the remediation of Cr and Cd in soil by SC was proposed. Cr was mainly converted into the relatively stable substances such as Cr2O3, Cr(OH)3 and FeCr2O4 through adsorption, reduction, complexation and precipitation processes, while Cd was converted into Cd(OH)2 and CdO through adsorption and precipitation processes. This study not only provides the theoretical basis and technical support for the remediation of heavy metals in soil using sludge-derived biochar, but also realizes the “treatment of waste with waste” of municipal sludge.

Key words: sludge-derived biochar, chromium (Cr), cadmium (Cd), soil remediation, contaminated soil

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