陇东黄土高原地区石油污泥原位修复过程中土壤主要肥力指标动态变化分析

为了分析陇东黄土高原地区石油污泥在原位修复过程中土壤主要肥力指标的变化情况,对长庆油田第二采油厂的石油污泥进行为期105 d的原位修复,采用常规方法测定了土壤有机质、pH、总石油烃含量(TPHs)、含盐率、碱解氮、速效磷、速效钾、土壤脲酶、脱氢酶、多酚氧化酶、过氧化氢酶等土壤肥力指标;通过PCR-DGGE技术分析了土壤微生物群落的功能多样性,并采用主成分分析法对供试石油污泥的土壤肥力进行评价.结果显示:随着原位修复的时间的延长,土壤碱解氮、速效磷含量呈显著增加趋势;有机质、pH、含盐率、TPHs含量显著降低,而速效钾含量呈逐步增加趋势.土壤脲酶及脱氢酶活性增加,多酚氧化酶及过氧化氢酶活性降低.土壤微生物群落遗传多样性结果显示,ShannonWiener多样性指数、Patrick丰富度指数及Pielou均匀度指数均呈增加的趋势.经过105 d的原位修复土壤肥力显著提升,各阶段土壤肥力得分为105 d80 d60 d45 d25 d.上述实验结果有助于掌握石油污泥原位修复中土壤肥力动态变化趋势,并为土壤石油烃污染的综合治理提供基础依据和数据参考.

Fertility dynamics of petroleum-contaminated sludge during in situ remediation in eastern Gansu Province

In order to analyze the comprehensive changes of soil fertility in oil-contaminated sludge via in-situ remediation in the Longdong region of Loess Plateau, oil-contaminated sludge samples were selected from the second production plant of Changqing oil field for in situ remediation by 105 days. Changes in soil organic matter, pH, total petroleum hydrocarbon content (TPHs), salt content, soil available nitrogen, phosphorus, and potassium concentrations, and activities of soil urease, dehydrogenase, polyphenol oxidase, catalase in oil-contaminated sludge were dynamically monitored. Functional diversity of microbial community in oil-contaminated sludge was analyzed based on PCR-DGGE, and principal component analysis was applied to assess evolution of soil fertility during the remediation processes. We found that soil available nitrogen, phosphorus and potassium concentrations and soil urease and dehydrogenase activities significantly increased with time, while soil organic matter, salt and total TPHs contents and pH value, and soil polyphenol oxidase and catalase activity significantly decreased. Microbial genetic diversity index of Shannon-Wiener, abundance index Patrick, and evenness index Pielou all showed an increase trend with time during in-situ remediation. We concluded that in situ remediation is a very effective measure to regenerate oil-contaminated sludge in soils.