富硅生物炭对重金属污染土壤的改良修复作用  

Modification and Remediation of Heavy Metals Contaminated Soil by Silicon-rich Biochar

作　　者：费颖恒 邓海燕 李敏烯 符月青 赵艺翔 FEI Yingheng;DENG Haiyan;LI Minxi;FU Yueqing;ZHAO Yixiang(School of Environmental Science and Engineering,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学环境科学与工程学院,广州广东510006

出　　处：《环境科学与技术》2021年第12期177-184,共8页Environmental Science & Technology

基　　金：国家自然科学基金(41907119);广东省自然科学基金(2019A1515011617);广州大学校内科研项目(YG2020013);广州大学大学生创新训练项目(CX2019345)。

摘　　要：富硅生物炭为同时解决耕作土壤硅流失与重金属污染两大问题提供了理论上的新思路,但目前对生物炭硅在土壤改良和修复方面的研究较少。文章为探讨富硅生物炭对土壤硅补充和对重金属固定作用及机理,实验施用富硅的水稻秸秆生物炭处理土壤,以无硅的红麻秆生物炭、除硅水稻秸秆生物炭和水溶性硅肥对照,分别于土壤中添加后培养25周,分析土壤中的有效硅、重金属形态及浸出量,论证富硅生物炭对土壤的多功能修复效果。结果表明,施加富硅生物炭可显著提高土壤中的有效硅,并促使铅、铜、锌等重金属由可交换态向更稳定的形态转化,从而降低土壤中重金属的浸出风险。经处理后的土壤中有效硅的降低与重金属的固定呈正相关关系。研究结果表明,富硅生物炭可从提高有效硅含量和固定重金属2个方面促进对污染土壤的多功能修复。Silicon-rich biochar provides novel strategy for simultaneously solving the problems of soil silicon deficiency and heavy metal pollution,while the practice and research was still rarely reported.To investigate the performance and mechanisms of the silicon-rich biochar improving the soil available silicon and immobilizing heavy metals,the rice straw derived biochar was applied as the silicon-rich biochar,while Miscanthus sinensis derived biochar,desiliconized rice straw biochar as well as soluble silicate were selected as references.During the 25 weeks of incubation after soil application,the soil available silicon,speciation of heavy metals and the leachable content of heavy metals were determined,to demonstrate the multi-functional restoration effects by the silicon-rich biochar.Results showed that the application of rice straw biochar significantly improved the soil available silicon,and promoted the transferring the heavy metals like lead,copper and zine from exchangeable fractions to more stable fractions so that lowed the leaching risks of heavy metals.The immobilized heavy metal content was found to be positively correlated with the relatively decreased available silicon.It was thus implied that silicon-rich biochar could effectively promote the multi-functional restoration of the polluted soil through both the ways of increasing the available silicon and immobilization heavy metals.

关 键 词：生物炭 硅 土壤有效硅 重金属 固定化 

分 类 号：X53[环境科学与工程—环境工程]