以安徽省皖南山区宣城市宣州区为代表,运用统计学方法、地统计学方法和GIS技术研究了农田表层(0~20 cm)土壤有机碳(SOC)含量的空间分布及其影响因子。统计结果表明:研究区SOC含量为7.69±3.07 g kg-1,SOC变异系数为39.88%,属于中等...以安徽省皖南山区宣城市宣州区为代表,运用统计学方法、地统计学方法和GIS技术研究了农田表层(0~20 cm)土壤有机碳(SOC)含量的空间分布及其影响因子。统计结果表明:研究区SOC含量为7.69±3.07 g kg-1,SOC变异系数为39.88%,属于中等变异程度。地统计分析结果表明,研究区SOC半方差模型为球状模型,存在中等的空间自相关性,随机性因子和结构性因子对其空间变异的影响同样重要。SOC含量在空间分布上表现为由东北向西南递减,大致呈斑块状分布。地形、土壤颗粒组成和秸秆还田是影响SOC空间变异的主要因素。展开更多
Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons（VCHs）. Conventionally, this technique is used ...Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons（VCHs）. Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures（silty,clayey, and sandy soils） along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform（TCM） and trichloroethylene（TCE）. Mechanical soil aeration was effective for remediating VCHs（removal efficiency 〉 98%）. The volatilization process was described by an exponential kinetic function.In the early stage of treatment（0–7 hr）, rapid contaminant volatilization followed a pseudofirst order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8 hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner.展开更多
文摘以安徽省皖南山区宣城市宣州区为代表,运用统计学方法、地统计学方法和GIS技术研究了农田表层(0~20 cm)土壤有机碳(SOC)含量的空间分布及其影响因子。统计结果表明:研究区SOC含量为7.69±3.07 g kg-1,SOC变异系数为39.88%,属于中等变异程度。地统计分析结果表明,研究区SOC半方差模型为球状模型,存在中等的空间自相关性,随机性因子和结构性因子对其空间变异的影响同样重要。SOC含量在空间分布上表现为由东北向西南递减,大致呈斑块状分布。地形、土壤颗粒组成和秸秆还田是影响SOC空间变异的主要因素。
基金supported by the National Environmental Protection Public Welfare projects(Nos.201409047 and 201109017)the “13th Five-Year Plan” National Key Research and Development Program of China(No.2016YFC0501108)+1 种基金the Fundamental Research Funds for the Central Universities(No.2016QH02)Beijing Natural Science Foundation(No.8152025)
文摘Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons（VCHs）. Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures（silty,clayey, and sandy soils） along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform（TCM） and trichloroethylene（TCE）. Mechanical soil aeration was effective for remediating VCHs（removal efficiency 〉 98%）. The volatilization process was described by an exponential kinetic function.In the early stage of treatment（0–7 hr）, rapid contaminant volatilization followed a pseudofirst order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8 hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner.
