生物炭耦合水分管理对稻田土壤As-Cd生物有效性及稻米累积的影响  

Bioavailability of arsenic and cadmium,and their cumulative control in rice grown on arsenic-cadmium-contaminated paddy soils

作　　者：李园星露 叶长城[1,2] 刘玉玲 杨蕊嘉[1,2] 何钟响 刘孝利 铁柏清 孙健[3] LIYUAN Xing-lu;YE Chang-cheng;LIU Yu-ling;YANG Rui-jia;HE Zhong-xiang;LIU Xiao-li;TIE Bo-qing;SUN Jian(College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China;Engineering Research Center of Effi- cient Utilization of Heavy Metal Pollution Cultivated, Hunan Province, Changsha 410013, China;School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China)

机构地区：[1]湖南农业大学资源环境学院,长沙410128 [2]湖南省重金属污染耕地安全高效利用工程研究中心,长沙410013 [3]广东工业大学环境科学与工程学院,广州510006

出　　处：《农业环境科学学报》2018年第4期696-704,共9页Journal of Agro-Environment Science

基　　金：国家科技支撑计划项目(2015BAD05B02-07);国家自然科学基金项目(41201511)~~

摘　　要：选取湖南某矿区重金属Cd、As复合污染稻田土,以泰优390号为材料,通过盆栽试验研究湿润灌溉(CK)、农艺措施淹水(WF)、竹炭(ZC)、竹炭结合淹水措施(ZF)、稻壳炭(GC)、稻壳炭结合淹水措施(GF),对土壤中As、Cd生物有效性及水稻糙米中As、Cd累积效应的影响。结果表明,6种处理土壤pH值上升幅度为0.12~0.72个单位,均呈现先升高再下降,最后趋于中性的规律。相比对照,水稻全生育期5种处理Eh值均呈现下降趋势,而单一添加生物炭ZC、GC 2种处理乳熟期Eh显著高于同一生育期配施生物炭的WF、ZF、GF 3种淹水处理,并始终处于弱还原状态。各处理均能显著降低成熟期土壤Cd的有效态、酸可提取态和TCLP提取态含量,而As的有效态和TCLP提取态含量显著升高。WF、ZF、GF淹水配施生物炭处理糙米中Cd含量降低51.46%~57.28%,其中GF抑制效果最佳,与ZF呈现显著性差异;而籽粒中As的含量分别达到0.29、0.32、0.30 mg·kg-1,较CK组升高了39.74%~53.58%,三者并无显著性差异。2种仅添加生物炭的ZC、GC处理与对照相比,糙米中Cd含量降低16.50%、39.81%,糙米中As含量增加了27.24%、12.23%,但GC与CK处理并无显著性差异。因此,WF、ZF、GF及ZC处理可减少土壤中Cd的生物有效性,对重金属Cd污染稻田土壤修复具有重要意义,但会增加土壤中As溶出的风险及其生物有效性。而单一添加生物炭的GC处理可用于Cd-As复合污染农田,为稻田土壤Cd-As复合污染粮食安全生产提供理论依据。In the present study, the arsenic （As） and cadmium （Cd）-contaminated soil from a mining area of Hunan Province was collected to study the effects of different treatments（CK： wet irrigation, WF ： agronomic measure flooding, ZC ：bamboo charcoal, ZF ：bamboo charcoal with irrigation, GC：chaff carbon, GF：chaff carbon with irrigation） on the bioavailability of As and Cd in soil and their accumulation in brown flee. The resuhs showed that the pH increased by 0.12-0.72 units in all the six treatments, which showed an increasing trend initially,and then decreased to neutral. Compared with CK, the Eh of soil subjected to other five treatments showed a decreasing trend. However, the Eh of soil subjected to treatments ZC and GC were significantly higher than that of the treatments WF, ZF, and GF flooded with biochar during the same growth stage, and was maintained in a weak reductive state. The concentration of available Cd, acid extractables, and TCLP extractables significantly decreased, while the concentration of available As and TCLP extractables significantly increased among all treatments. The content of Cd in brown rice subjected to the treatments WF, ZF, and GF flooded with biochar decreased by 51.46%-57.28%, and the optimal inhibition effect for Cd was achieved by the treatments GF, which was significantly different from that of ZF treatment. The content of As in the grain reached 0.29, 0.32 mg·kg^-1, and 0.30 mg·kg^-1, 39.74%-53.58% higher than that of the CK. There was no significant difference among the three groups. The content of Cd in brown rice decreased by 16.50% and 39.81%, while the content of As in brown rice increased by 27.24% and 12.23%. However, there was no significant difference between the treatment groups GC and CK. These results indicate that the treatments WF, ZF, GF, and ZC can reduce the bioavailability of Cd in soils, which will be of great significance to remediate Cd-contaminated paddy soils. However, it can increase the bioavailability of As in soil. Furthermore,

关 键 词：镉 砷 复合污染 竹炭 稻壳炭 淹水 稻田土壤 

分 类 号：X53[环境科学与工程—环境工程]