摘要
针对油田产出水导致的含油盐污染耕地的生物强化修复,提出在土壤耕作层和主体层间填埋麦秸以强化水浸洗盐和抑制毛细返盐.结果表明,土壤中石油烃的浓度高于1.5%(质量分数)时会导致其疏水性增高而使得水浸润困难.添加5%(质量分数)麦秸可使含油3.3%(质量分数)的盐污染土壤脱盐率从3%提高到25%,并可抑制毛细返盐.在中原油田实施了6 400m2的现场实验,在耕作层(距地表25 cm)构建麦秸层,采用井水以及雨水进行洗盐,50 d后耕作层土壤电导率达到正常耕地水平的面积比例由17%提高到80%,Na+和Cl-浓度分别从1 642.5 mg.kg-1和1 301.2 mg.kg-1下降到499.3 mg.kg-1和433.8mg.kg-1.修复地块的小麦产量达正常耕地的72%,而对比地块仅为12%.说明添加麦秸可强化油盐混合污染耕地的水浸洗盐并抑制"毛细返盐".该方法操作便捷易行,在油盐混合污染耕地修复中具有很好的应用前景.
A new remediation method for petroleum-salt contaminated soil was proposed, in which wheat straw was applied to enhance salt leaching and meanwhile block salt upmovement along the soil capillary. It was shown that the existence of petroleum increased the surface hydrophobicity of soil and thus hindered the leaching process once the oil content was above 1.5 % （mass fraction）. The application of 5% （mass fraction） wheat straw into the soil increased the efficiency of salt leaching from 3 % to 25 %. The effectiveness of wheat straw layer in inhibiting the salt upmovement along the soil capillary was also proven. Field test of this method was carried out in an area of 6 400 m^2 , in which wheat straw layer of 5 cm was distributed in the depth of 25 cm. After 50 days, 80% of the testing area showed a normal soil electronic conductivity （ soil EC 〈 5 mS·cm^-1） in contrast to 17 % before leaching process. The concentrations of Na ^＋ and Cl^- were decreased from 1 642.5 mg·kg^-1 and 1 301.2 mg·kg^-1 to 499.3 mg·kg^-1 and 433.8 mg·kg^-1 , respectively. The remediated land upon the implementation of wheat straw gave a 72 % of the regular wheat production obtained from the normal farmland, while the control land without wheat straw gave 12% . These results demonstrated the effectiveness and the high potential of using wheat straw for the salt leaching in remediation of petroleumsalt contaminated soil.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第1期231-236,共6页
Environmental Science
基金
中国石油化工股份有限公司科学技术研究开发项目(306038)
关键词
盐污染
石油
治理
水浸洗盐
麦秸
salt contamination
petroleum
remediation
salt leaching
wheat straw
