特选榨菜对铀污染土壤的修复评价  

Evaluation on remediation of Uranium contaminated soils by brassica mustard

作　　者：查忠勇[1] 王定娜[2] 冯孝杰[3] 刘黎[2] 方振东[1] 夏传琴[2] 

机构地区：[1]后勤工程学院化学与材料工程系,重庆401311 [2]四川大学化学学院,四川成都610064 [3]后勤工程学院国防建设规划与环境工程系,重庆401311

出　　处：《化学研究与应用》2014年第2期223-229,共7页Chemical Research and Application

基　　金：国家自然科学基金(10776021);中国人民解放军总后勤部基建营房部项目(CY112C018)

摘　　要：本文通过两种不同的加铀方式,加入不同种类及浓度的螯合剂,以及土壤改良剂(有机肥、微生物肥料、腐殖酸、尿素)的方法,研究了不同因素对特选榨菜修复铀污染土壤的影响。结果表明:在pH=5时把UO_2(NO_3)_2·6H_2O溶液喷洒入土壤,使土壤中铀污染浓度为100 mg·kg^(-1)时,特选榨菜地上部铀富集的浓度最大可以达到1103.42 mg·kg^(-1),根部为1909.49 mg·kg^(-1),去除率为7.81%;上述含铀土壤放置2年后制备成模拟铀污染的土壤,进而栽种特选榨菜进行修复,在100 mg·kg^(-1)铀污染浓度下,植物上部铀富集浓度最大为295.83 mg·kg^(-1),根部为268.42 mg·kg^(-1),年去除率为2.52%。用Tessier五步连续提取法测定两次修复土壤中铀的形态,发现模拟铀污染土壤比铀喷洒于土壤中有效态的铀(交换态和碳酸盐结合态)要低52.7%;加入柠檬酸、苹果酸等螯合剂以及有机肥、微生物肥料、腐殖酸、尿素等土壤改良剂,在模拟铀污染土壤修复时发现有机肥会降低植物上部对铀的富集;而柠檬酸和微生物肥会增强植物上部对铀的富集。There are many factors influencing the remediation of uranium contaminated soils by mustard.Several aspects were dis-cussed in this paper,such as two different ways of adding uranium solution ,chelators of different kinds and concentrations ,and four soil amendments（organic fertilizer,microbial fertilizer,humic acid,urea）.Results showed that when UO 2（NO3 ） 2？6H2 O was added to the soils at pH 5,with a initial uranium concentration of 100 mg.kg-1 in soils,U-concentration in shoots of mustard could reach 1103.42 mg.kg-1 ,and 1909.49 mg.kg-1 in roots,with an annual removal rate of 7.81%.While the above soil,laid for two years, was modeled to be the real soil contaminated with uranium and remedied by mustard.U concentration in shoots of the plants only reached 295.83 mg.kg-1 ,and 268.42 mg.kg-1 in roots,and the annual removal rate was merely 2.52%.By using Tessier-five-step continuous extraction method for determination of uranium speciation in soils ,we found the available uranium（exchangeable urani-um,uranium carbonate ） in the modeled soils with uranium contamination was 52.7%lower than that in the soils with U addi-tion.Studies on chelators（Citric acids,Malic acids） and soil amendments （organic fertilizer,microbe fertilizer,humic acid,urea） showed that organic fertilizer could reduce the uranium concentration on the shoots of Brassica mustard ,yet citric acid and microbe fertilizer could increase the uranium concentration in the shoots.

关 键 词：植物修复 特选榨菜 螯合剂 铀污染土壤 

分 类 号：O614.62[理学—无机化学]