北京市污染场地土壤修复工程实证分析

Empirical analysis on soil remediation constructions of contaminated sites in Beijing.

为探究区域尺度污染土壤修复特征,以北京市2006~2021年51个污染场地修复工程为基础,对修复技术与方量进行统计,利用物质流方法探究污染土壤与污染物通量及归趋,并以因子法估算修复行为产生的碳排放.结果表明:北京市2006~2021年修复污染土壤819.18万m^(3),其中有机、复合、无机污染土壤分别占88.13%、10.23%和1.64%;修复技术以异位为主,方量占82.92%;修复后土壤去向主要为异地填埋(46.02%)和资源化利用(35.18%),而原位修复(15.25%)、风险管控(1.83%)以及原场回填(1.72%)占比较小;修复6类特征污染物共计9943.70t,其中苯系物239.89t、氯代烃1502.12t、多环芳烃510.36t、石油烃4908.52t、重金属2768.33t、农药类14.48t;修复行为排放CO_(2)58.34万t,排放强度逐步下降.建议1)保障修复效果前提下,优先低碳修复技术及资源化利用模式;2)减少区域土壤修复特征污染物的扰动和输送通量,降低能源、材料等投入消耗;3)精细构建区域场地修复可持续度评估方法,构建土壤资源永续利用的强可持续修复管理模式.

In order to identify the remediation characteristics of contaminated soil at regional scales,the remediation technologies and volumes based on 51remediation sites in Beijing from 2006 to 2021 were statistically analyzed.The material flow method was used to explore the flux and trend of contaminated soil and contaminants,and the factor method was used to estimate the carbon emissions generated by remediation behaviours.The results showed that the remediation volume of contaminated soil in Beijing during the past 16years was 8.1918 million m^(3),of which 88.13%,10.23%and 1.64%were organic,organic-inorganic composite and inorganic contaminated soil,respectively.The remediation technologies used were mainly ex-situ,accounting for 82.92%of the total remediated soil volume.The main destinations of remediated soil were landfill(46.02%)and resource utilization(35.18%),while in-situ remediation(15.25%),risk control(1.83%)and backfilling(1.72%)were relatively minor.A total of 9943.70t of 6types of characteristic contaminants were treated,including 239.89t of benzene series,1502.12t of chlorinated hydrocarbons,510.36t of polycyclic aromatic hydrocarbons,4908.52t of petroleum hydrocarbons,2768.33t of heavy metals and 14.48t of pesticides.The total amount of CO_(2)emitted by the remediation was 583400 tons,and the emission intensity gradually decreased.It is suggested that,firstly,give priority to low-carbon remediation technologies and resource utilization models;secondly,reduce the disturbance and transportation flux of characteristic contaminants remediated in regional scales,and reduce the input consumption of energy and materials;thirdly,elaborate the sustainable degree assessment method of regional contaminated sites remediation,and build a strong management model for sustainable use of soil resources.