污染场地地下水环境污染风险分级评价方法研究

徐瑞颖1，牛浩博2*，罗朝晖1，陈(chen) 坚2，刘伟江3

(1.中(zhong)国地质大学(xue)(xue)(武汉)环(huan)境(jing)(jing)(jing)学(xue)(xue)院；2.生(sheng)态(tai)环(huan)境(jing)(jing)(jing)部环(huan)境(jing)(jing)(jing)规划(hua)院3.生(sheng)态(tai)环(huan)境(jing)(jing)(jing)部土壤与(yu)农业农村生(sheng)态(tai)环(huan)境(jing)(jing)(jing)监(jian)管技术中(zhong)心，)

《安全与环境工程》 2022年第1期

摘 要：目前我(wo)国的污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)分(fen)(fen)(fen)级评价(jia)方(fang)法(fa)不能完全适合(he)环境(jing)(jing)管理(li)的要求(qiu)。从(cong)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)源负荷、污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)物释(shi)放(fang)可(ke)能性(xing)(xing)、受体特(te)征三个方(fang)面，运用层次(ci)分(fen)(fen)(fen)析(xi)法(fa)和(he)灵敏(min)度(du)分(fen)(fen)(fen)析(xi)法(fa)对污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)分(fen)(fen)(fen)级评价(jia)指(zhi)标进(jin)行(xing)筛选(xuan)和(he)权重计算，构(gou)建(jian)了(le)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)分(fen)(fen)(fen)级评价(jia)方(fang)法(fa)，将污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)划分(fen)(fen)(fen)为高、中、低三级，并(bing)(bing)运用所构(gou)建(jian)的评价(jia)方(fang)法(fa)对两个典型污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)进(jin)行(xing)分(fen)(fen)(fen)级评价(jia)与验证。结果表明：采(cai)用该评价(jia)方(fang)法(fa)得到的污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)(feng)险(xian)评价(jia)结果与现有评价(jia)方(fang)法(fa)的评价(jia)结果基本一致，并(bing)(bing)且可(ke)极大地(di)(di)(di)减少(shao)评价(jia)指(zhi)标筛选(xuan)及权重确定的主观性(xing)(xing)，适合(he)于(yu)不同(tong)特(te)征污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)物场(chang)地(di)(di)(di)地(di)(di)(di)下(xia)(xia)(xia)水(shui)(shui)(shui)环境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)的风(feng)(feng)(feng)险(xian)评价(jia)，验证了(le)所构(gou)建(jian)的评价(jia)方(fang)法(fa)具有合(he)理(li)性(xing)(xing)和(he)可(ke)靠性(xing)(xing)。该评价(jia)结果可(ke)为国家层面的污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)分(fen)(fen)(fen)级管理(li)提供科(ke)学依据。

关键词(ci)：污(wu)染场(chang)地；地下水环境污(wu)染；风险分级(ji)；层次分析法；灵敏度(du)分析法

20世纪80年代以来(lai)，欧美发达国家(jia)(jia)逐(zhu)步(bu)将污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)问题纳(na)入国家(jia)(jia)环(huan)(huan)(huan)境(jing)管(guan)理(li)(li)体(ti)系(xi)中(zhong)，并(bing)形成了完整、成熟的(de)(de)污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)管(guan)理(li)(li)体(ti)系(xi)。目前(qian)，我国污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)管(guan)理(li)(li)相关(guan)(guan)的(de)(de)法(fa)(fa)(fa)(fa)(fa)律法(fa)(fa)(fa)(fa)(fa)规(gui)、相应的(de)(de)评(ping)(ping)(ping)(ping)价方法(fa)(fa)(fa)(fa)(fa)和管(guan)理(li)(li)体(ti)系(xi)已(yi)经逐(zhu)渐建(jian)(jian)立起(qi)来(lai)，但在污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)分(fen)(fen)(fen)(fen)类(lei)管(guan)理(li)(li)方面还处于起(qi)步(bu)阶段[1-2]。2017年，为了支撑全国土壤环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)状况详查(cha)工作，建(jian)(jian)立了优先(xian)管(guan)控名录，对(dui)重点行(xing)业(ye)(ye)出(chu)台了《关(guan)(guan)闭搬迁企业(ye)(ye)地(di)(di)(di)块(kuai)风(feng)(feng)险(xian)(xian)(xian)筛查(cha)与风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)技术规(gui)定(试行(xing))》。该规(gui)定中(zhong)对(dui)污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)等(deng)(deng)级(ji)评(ping)(ping)(ping)(ping)估主要(yao)(yao)基于初步(bu)采(cai)(cai)样调查(cha)结果，采(cai)(cai)用(yong)“源—途径—受体(ti)”风(feng)(feng)险(xian)(xian)(xian)三要(yao)(yao)素(su)(su)的(de)(de)评(ping)(ping)(ping)(ping)价方法(fa)(fa)(fa)(fa)(fa)。与发达国家(jia)(jia)污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)管(guan)理(li)(li)体(ti)系(xi)相比，该评(ping)(ping)(ping)(ping)价方法(fa)(fa)(fa)(fa)(fa)考(kao)虑(lv)的(de)(de)因(yin)(yin)素(su)(su)较少(shao)，评(ping)(ping)(ping)(ping)价指(zhi)标赋分(fen)(fen)(fen)(fen)方法(fa)(fa)(fa)(fa)(fa)主观性较强。另外，污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)分(fen)(fen)(fen)(fen)类(lei)系(xi)统仅仅是一(yi)(yi)个筛查(cha)工具，是否(fou)需要(yao)(yao)采(cai)(cai)取修复行(xing)动(dong)还依赖于大量因(yin)(yin)素(su)(su)[3]。美国环(huan)(huan)(huan)境(jing)保护署(EPA)于1995年8月设(she)立了一(yi)(yi)个由(you)项目专家(jia)(jia)组成的(de)(de)国家(jia)(jia)风(feng)(feng)险(xian)(xian)(xian)优先(xian)小组，对(dui)污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)评(ping)(ping)(ping)(ping)估的(de)(de)方法(fa)(fa)(fa)(fa)(fa)除了考(kao)虑(lv)对(dui)人体(ti)健康和环(huan)(huan)(huan)境(jing)风(feng)(feng)险(xian)(xian)(xian)有关(guan)(guan)的(de)(de)指(zhi)标外，还考(kao)虑(lv)了创新技术、成本延迟、环(huan)(huan)(huan)境(jing)正义(yi)等(deng)(deng)指(zhi)标，该机构(gou)利用(yong)这些指(zhi)标评(ping)(ping)(ping)(ping)估为超级(ji)基金(jin)(jin)项目中(zhong)所(suo)有新的(de)(de)清洁建(jian)(jian)设(she)项目确定资金(jin)(jin)的(de)(de)优先(xian)使(shi)用(yong)次序(xu)[4]。由(you)此可(ke)见，对(dui)于确定污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)修复的(de)(de)优先(xian)顺(shun)序(xu)需要(yao)(yao)考(kao)虑(lv)的(de)(de)因(yin)(yin)素(su)(su)是多(duo)途径、多(duo)方面的(de)(de)，我国目前(qian)的(de)(de)污(wu)(wu)(wu)染(ran)(ran)场(chang)地(di)(di)(di)环(huan)(huan)(huan)境(jing)污(wu)(wu)(wu)染(ran)(ran)风(feng)(feng)险(xian)(xian)(xian)分(fen)(fen)(fen)(fen)级(ji)评(ping)(ping)(ping)(ping)价方法(fa)(fa)(fa)(fa)(fa)仍需进一(yi)(yi)步(bu)改进。

污染(ran)(ran)场地(di)(di)地(di)(di)下(xia)水环境污染(ran)(ran)风(feng)险(xian)(xian)分(fen)(fen)级(ji)评价(jia)的方(fang)法主要有(you)迭置(zhi)指(zhi)数(shu)法、过(guo)程模拟(ni)法和(he)统(tong)(tong)(tong)计分(fen)(fen)析法。其中，迭置(zhi)指(zhi)数(shu)法是通(tong)过(guo)构建表征污染(ran)(ran)场地(di)(di)地(di)(di)下(xia)水环境污染(ran)(ran)风(feng)险(xian)(xian)的评价(jia)指(zhi)标体系，按照(zhao)特定(ding)的评分(fen)(fen)原则(ze)得到分(fen)(fen)级(ji)对象的风(feng)险(xian)(xian)指(zhi)数(shu)，并(bing)根据风(feng)险(xian)(xian)指(zhi)数(shu)评价(jia)污染(ran)(ran)场地(di)(di)地(di)(di)下(xia)水环境污染(ran)(ran)风(feng)险(xian)(xian)的大小[5-7]，如(ru)美(mei)国污染(ran)(ran)场地(di)(di)危害等级(ji)打分(fen)(fen)系统(tong)(tong)(tong)(HRS)、加拿(na)大污染(ran)(ran)场地(di)(di)国家分(fen)(fen)级(ji)系统(tong)(tong)(tong)

(NCSCS)等(deng)，该方(fang)法(fa)(fa)(fa)(fa)考虑指(zhi)标全面、计算简单(dan)方(fang)便，但(dan)在确定评价(jia)(jia)指(zhi)标权(quan)(quan)重(zhong)时存在较(jiao)(jiao)强(qiang)的(de)主(zhu)(zhu)观(guan)(guan)性(xing)，且对(dui)(dui)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)形成的(de)机(ji)理(li)描(miao)述得不够全面[8-9]；过(guo)(guo)程模拟法(fa)(fa)(fa)(fa)通常是基(ji)于(yu)水(shui)流和溶(rong)质(zhi)运(yun)移模型(xing)，模拟污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)在介质(zhi)中迁移转化的(de)时空变化规律(lv)[10-11]，如(ru)RBCA、3MRA、HERA等(deng)模型(xing)，该方(fang)法(fa)(fa)(fa)(fa)对(dui)(dui)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)在环(huan)(huan)(huan)(huan)境(jing)(jing)介质(zhi)中的(de)迁移转化过(guo)(guo)程进行了(le)定量(liang)化描(miao)述，主(zhu)(zhu)观(guan)(guan)性(xing)低(di)，但(dan)过(guo)(guo)程模拟法(fa)(fa)(fa)(fa)需要(yao)收(shou)集大(da)量(liang)的(de)参数(shu)(shu)(shu)，操作(zuo)性(xing)较(jiao)(jiao)差，对(dui)(dui)于(yu)全国性(xing)的(de)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)风险(xian)分(fen)级(ji)(ji)分(fen)类管理(li)而言不易(yi)(yi)推广(guang)[12]；统(tong)计分(fen)析(xi)法(fa)(fa)(fa)(fa)是基(ji)于(yu)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)监测(ce)数(shu)(shu)(shu)据及(ji)资料，运(yun)用(yong)统(tong)计学(xue)方(fang)法(fa)(fa)(fa)(fa)(如(ru)聚(ju)类分(fen)析(xi)、主(zhu)(zhu)成分(fen)分(fen)析(xi)等(deng)方(fang)法(fa)(fa)(fa)(fa))筛选出(chu)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)的(de)主(zhu)(zhu)要(yao)影响(xiang)因素，并(bing)通过(guo)(guo)回(hui)归(gui)方(fang)程给出(chu)其适当的(de)权(quan)(quan)重(zhong)值，该方(fang)法(fa)(fa)(fa)(fa)避(bi)免了(le)专家(jia)评判的(de)主(zhu)(zhu)观(guan)(guan)性(xing)，但(dan)需要(yao)大(da)量(liang)的(de)实际(ji)数(shu)(shu)(shu)据，其应用(yong)受(shou)到(dao)限(xian)制[13-14]。目前污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)风险(xian)的(de)分(fen)级(ji)(ji)评价(jia)(jia)方(fang)法(fa)(fa)(fa)(fa)多采用(yong)迭置指(zhi)数(shu)(shu)(shu)法(fa)(fa)(fa)(fa)，但(dan)该方(fang)法(fa)(fa)(fa)(fa)主(zhu)(zhu)观(guan)(guan)性(xing)较(jiao)(jiao)强(qiang)[8-9,15]。为了(le)保证污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)风险(xian)分(fen)级(ji)(ji)评价(jia)(jia)过(guo)(guo)程的(de)易(yi)(yi)操作(zuo)性(xing)，降低(di)评价(jia)(jia)指(zhi)标筛选及(ji)权(quan)(quan)重(zhong)确定过(guo)(guo)程中的(de)主(zhu)(zhu)观(guan)(guan)性(xing)，使评价(jia)(jia)结果更加客观(guan)(guan)合理(li)，本(ben)文(wen)基(ji)于(yu)迭置指(zhi)数(shu)(shu)(shu)法(fa)(fa)(fa)(fa)并(bing)结合层次分(fen)析(xi)法(fa)(fa)(fa)(fa)和灵敏度分(fen)析(xi)法(fa)(fa)(fa)(fa)，构(gou)建了(le)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)风险(xian)分(fen)级(ji)(ji)评价(jia)(jia)方(fang)法(fa)(fa)(fa)(fa)，以期(qi)为后续制定综合、全面的(de)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环(huan)(huan)(huan)(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)风险(xian)分(fen)级(ji)(ji)管理(li)方(fang)法(fa)(fa)(fa)(fa)提供(gong)借鉴。

1 研究方法

1.1 评价指标选取方法

土壤(rang)中(zhong)的(de)污(wu)染物(wu)(wu)经淋(lin)(lin)滤作用(yong)(yong)进入包(bao)气带和含(han)水(shui)(shui)层，可(ke)在(zai)包(bao)气带介(jie)质(zhi)(zhi)和含(han)水(shui)(shui)层介(jie)质(zhi)(zhi)中(zhong)发生各种稀释(shi)衰减(jian)作用(yong)(yong)[11-17]。稀释(shi)衰减(jian)模型(xing)可(ke)对(dui)污(wu)染物(wu)(wu)在(zai)包(bao)气带和含(han)水(shui)(shui)层中(zhong)释(shi)放的(de)可(ke)能(neng)(neng)性(xing)进行定量化描述，如早期用(yong)(yong)于评(ping)估农业(ye)区(qu)(qu)农药(yao)污(wu)染地下(xia)(xia)(xia)水(shui)(shui)脆(cui)弱性(xing)的(de)衰减(jian)因(yin)子(zi)指数(shu)模型(xing)——AF、PRZM模型(xing)，模型(xing)结果(guo)的(de)取(qu)(qu)值范围为0～1。当(dang)模型(xing)结果(guo)取(qu)(qu)值为1时，表明(ming)土壤(rang)中(zhong)所有污(wu)染物(wu)(wu)都有可(ke)能(neng)(neng)渗入地下(xia)(xia)(xia)水(shui)(shui)；而(er)当(dang)模型(xing)结果(guo)取(qu)(qu)值为0时，表明(ming)土壤(rang)中(zhong)所有污(wu)染物(wu)(wu)不会(hui)渗入地下(xia)(xia)(xia)水(shui)(shui)[18-19]。姚文(wen)锋[20]采(cai)用(yong)(yong)包(bao)气带的(de)氮淋(lin)(lin)溶系(xi)数(shu)即衰减(jian)因(yin)子(zi)对(dui)研(yan)究区(qu)(qu)地下(xia)(xia)(xia)水(shui)(shui)水(shui)(shui)质(zhi)(zhi)脆(cui)弱性(xing)进行了(le)评(ping)价(jia)，结果(guo)表明(ming)：包(bao)气带氮淋(lin)(lin)溶系(xi)数(shu)越(yue)(yue)小，则(ze)地下(xia)(xia)(xia)水(shui)(shui)水(shui)(shui)质(zhi)(zhi)脆(cui)弱性(xing)越(yue)(yue)低；相反，如果(guo)包(bao)气带氮淋(lin)(lin)溶系(xi)数(shu)越(yue)(yue)大，表明(ming)包(bao)气带中(zhong)氮素的(de)损失量越(yue)(yue)少，则(ze)地下(xia)(xia)(xia)水(shui)(shui)水(shui)(shui)质(zhi)(zhi)脆(cui)弱性(xing)越(yue)(yue)高。本文(wen)选取(qu)(qu)模拟污(wu)染物(wu)(wu)在(zai)土壤(rang)中(zhong)迁移(yi)运输过程(cheng)的(de)稀释(shi)衰减(jian)模型(xing)，对(dui)土壤(rang)中(zhong)污(wu)染物(wu)(wu)释(shi)放的(de)可(ke)能(neng)(neng)性(xing)进行评(ping)价(jia)。稀释(shi)衰减(jian)模型(xing)的(de)计(ji)算公式如下(xia)(xia)(xia)：

(1)

式(shi)(shi)(shi)中：LF为(wei)(wei)土(tu)(tu)壤(rang)稀释衰(shuai)(shuai)减(jian)因(yin)(yin)子(zi)(g/cm3)；SAM为(wei)(wei)土(tu)(tu)壤(rang)衰(shuai)(shuai)减(jian)因(yin)(yin)子(zi)(无(wu)(wu)量纲)，计算(suan)式(shi)(shi)(shi)见(jian)公(gong)式(shi)(shi)(shi)(2)；LDF为(wei)(wei)土(tu)(tu)壤(rang)淋滤因(yin)(yin)子(zi)(无(wu)(wu)量纲)，计算(suan)式(shi)(shi)(shi)见(jian)公(gong)式(shi)(shi)(shi)(3)；Ksw为(wei)(wei)总土(tu)(tu)壤(rang)-水(shui)分配(pei)系数(cm3/g)，计算(suan)式(shi)(shi)(shi)见(jian)公(gong)式(shi)(shi)(shi)(4)；BDF为(wei)(wei)生物衰(shuai)(shuai)减(jian)因(yin)(yin)子(zi)(无(wu)(wu)量纲)，计算(suan)式(shi)(shi)(shi)见(jian)公(gong)式(shi)(shi)(shi)(5)；TAF为(wei)(wei)时间平均因(yin)(yin)子(zi)(无(wu)(wu)量纲)，计算(suan)式(shi)(shi)(shi)见(jian)公(gong)式(shi)(shi)(shi)(6)。具体计算(suan)公(gong)式(shi)(shi)(shi)如下：

(2)

(3)

(4)

(5)

(6)

式(shi)(shi)中：L1为(wei)污染(ran)土(tu)层(ceng)厚(hou)度(du)(m)；L2为(wei)土(tu)壤包(bao)(bao)气带厚(hou)度(du)(m)；I为(wei)土(tu)壤水(shui)(shui)入渗速(su)率(m/a)；v为(wei)地下水(shui)(shui)流速(su)(m/d)，计(ji)算式(shi)(shi)见公(gong)式(shi)(shi)(7)；δ为(wei)地下水(shui)(shui)混合区厚(hou)度(du)(m)；W为(wei)污染(ran)源宽(kuan)度(du)(m)；θws为(wei)土(tu)壤包(bao)(bao)气带孔隙水(shui)(shui)体(ti)积比(bi)(无(wu)量纲(gang))；Kd为(wei)土(tu)壤-水(shui)(shui)分配系数(shu)(shu)(cm3/g)，计(ji)算式(shi)(shi)见公(gong)式(shi)(shi)(8)；ρb为(wei)土(tu)壤干容重(g/cm3)；H′为(wei)环境温度(du)下的亨利(li)常数(shu)(shu)；θas为(wei)土(tu)壤包(bao)(bao)气带孔隙空气体(ti)积比(bi)(无(wu)量纲(gang))；λ为(wei)一阶衰减常数(shu)(shu)(d-1)；Bw为(wei)自由水(shui)(shui)分配系数(shu)(shu)(无(wu)量纲(gang))，计(ji)算式(shi)(shi)见公(gong)式(shi)(shi)(9)；ED为(wei)暴露(lu)周期(qi)(a)。具体(ti)计(ji)算公(gong)式(shi)(shi)如(ru)下：

v=K×i

(7)

Kd=Koc×foc

(8)

Bw=θws+Kdρb+Hθas

(9)

上式中：K为含水(shui)(shui)层水(shui)(shui)力传导系(xi)数(m/d)；i为水(shui)(shui)力梯度(无(wu)量纲(gang))；Koc为有机碳-水(shui)(shui)分配系(xi)数(cm3/g)；foc为土壤有机碳含量(g/g)；H为亨利常数(无(wu)量纲(gang))。

模(mo)(mo)型(xing)(xing)参(can)数灵(ling)敏度(du)分(fen)析(xi)是(shi)描述模(mo)(mo)型(xing)(xing)输入的(de)变化对(dui)模(mo)(mo)型(xing)(xing)输出响(xiang)(xiang)应(ying)的(de)影响(xiang)(xiang)程(cheng)度(du)，在决策分(fen)析(xi)、风险评估、模(mo)(mo)型(xing)(xing)简化及优化等(deng)多(duo)个方面(mian)得(de)到了(le)广泛(fan)应(ying)用(yong)[21-24]。由于(yu)稀(xi)释(shi)衰(shuai)减模(mo)(mo)型(xing)(xing)所含(han)的(de)参(can)数较(jiao)多(duo)且计算过程(cheng)繁琐，故本(ben)文(wen)(wen)采用(yong)灵(ling)敏度(du)分(fen)析(xi)方法(fa)对(dui)稀(xi)释(shi)衰(shuai)减模(mo)(mo)型(xing)(xing)参(can)数进行分(fen)析(xi)，识别(bie)出主要(yao)的(de)影响(xiang)(xiang)参(can)数并将(jiang)其作为污(wu)染(ran)(ran)物(wu)释(shi)放可能性(xing)(xing)评价指标(biao)，以此(ci)降低指标(biao)筛(shai)选(xuan)的(de)主观性(xing)(xing)。但由于(yu)稀(xi)释(shi)衰(shuai)减模(mo)(mo)型(xing)(xing)模(mo)(mo)拟(ni)污(wu)染(ran)(ran)物(wu)在环境介质中的(de)迁移转化过程(cheng)时(shi)对(dui)污(wu)染(ran)(ran)源负荷(he)和受体(ti)特征(zheng)等(deng)相(xiang)关(guan)要(yao)素的(de)考虑不(bu)足(zu)，故本(ben)文(wen)(wen)通过查阅相(xiang)关(guan)文(wen)(wen)献资料并结合已有(you)的(de)研究成果还选(xuan)取了(le)污(wu)染(ran)(ran)源负荷(he)和受体(ti)特征(zheng)评价指标(biao)，最(zui)终将(jiang)污(wu)染(ran)(ran)源负荷(he)、污(wu)染(ran)(ran)物(wu)释(shi)放可能性(xing)(xing)和受体(ti)特征(zheng)三(san)个方面(mian)的(de)评价指标(biao)加权叠加构建了(le)污(wu)染(ran)(ran)场(chang)地地下水(shui)环境污(wu)染(ran)(ran)风险分(fen)级评价方法(fa)，具体(ti)思(si)路流程(cheng)图(tu)(tu)见图(tu)(tu)1。

图1 污(wu)染场(chang)地地下(xia)水环境污(wu)染风(feng)险分级评价(jia)方(fang)法构建流程图

Fig.1 Flow chart of groundwater pollution risk classification evaluation method for contaminated sites

1.2 评价指标权重的确定方法

评(ping)价(jia)指(zhi)(zhi)(zhi)标(biao)权(quan)重(zhong)的(de)确(que)(que)定(ding)方(fang)法(fa)(fa)(fa)主要有(you)专家(jia)打分法(fa)(fa)(fa)、层(ceng)次(ci)分析(xi)(xi)法(fa)(fa)(fa)等[25-26]。其中，专家(jia)打分法(fa)(fa)(fa)具有(you)较强的(de)主观(guan)随意性(xing)，客观(guan)性(xing)差(cha)；层(ceng)次(ci)分析(xi)(xi)法(fa)(fa)(fa)将(jiang)相关评(ping)价(jia)指(zhi)(zhi)(zhi)标(biao)按支配关系分成(cheng)若干层(ceng)次(ci)，对(dui)同(tong)一(yi)层(ceng)次(ci)各评(ping)价(jia)指(zhi)(zhi)(zhi)标(biao)进(jin)行两两比较，以获得各评(ping)价(jia)指(zhi)(zhi)(zhi)标(biao)间的(de)相对(dui)重(zhong)要性(xing)，但在确(que)(que)定(ding)指(zhi)(zhi)(zhi)标(biao)相对(dui)重(zhong)要性(xing)时仍具有(you)一(yi)定(ding)的(de)主观(guan)性(xing)[27-28]。因此，本文将(jiang)模型(xing)参(can)数的(de)灵敏度分析(xi)(xi)结果(guo)与层(ceng)次(ci)分析(xi)(xi)法(fa)(fa)(fa)相结合(he)，对(dui)灵敏度较高的(de)参(can)数赋(fu)予更高的(de)权(quan)重(zhong)，以此来降低(di)评(ping)价(jia)指(zhi)(zhi)(zhi)标(biao)权(quan)重(zhong)确(que)(que)定(ding)过(guo)程中的(de)主观(guan)性(xing)。

1.3 评价指标分级评分方法

各评(ping)(ping)价(jia)指标(biao)(biao)内(nei)(nei)部分(fen)(fen)级(ji)值(zhi)参(can)考(kao)相关(guan)文(wen)献(xian)，优先参(can)考(kao)已有评(ping)(ping)价(jia)模型中的(de)评(ping)(ping)价(jia)指标(biao)(biao)分(fen)(fen)级(ji)，若(ruo)国内(nei)(nei)外(wai)参(can)考(kao)文(wen)献(xian)中未有说明(ming)，可查(cha)阅国内(nei)(nei)外(wai)相关(guan)污染(ran)因子分(fen)(fen)级(ji)标(biao)(biao)准，并根(gen)据各评(ping)(ping)价(jia)指标(biao)(biao)实际风(feng)险大小(xiao)且结合专家对评(ping)(ping)价(jia)指标(biao)(biao)的(de)评(ping)(ping)分(fen)(fen)情况进行分(fen)(fen)级(ji)评(ping)(ping)价(jia)，评(ping)(ping)分(fen)(fen)值(zhi)范围为1～10[25-26,29]。

1.4 总分计算方法

污(wu)染场地地下水环境(jing)污(wu)染风(feng)险评价综合指(zhi)数的总(zong)分计(ji)算(suan)采用评价指(zhi)标加权求和法，其计(ji)算(suan)公式(shi)如下：

(10)

式(shi)中(zhong)：m为(wei)评价指标的个数(shu)(个)；xi为(wei)评价指标i的评分值(分)；wi为(wei)评价指标i的总权重；R为(wei)污染(ran)(ran)场地地下水环(huan)境污染(ran)(ran)风险评价综合指数(shu)的总分值。

评(ping)价(jia)结果R取值(zhi)(zhi)范围为(wei)1～10分(fen)，根据污(wu)(wu)染场地(di)得(de)分(fen)值(zhi)(zhi)(R值(zhi)(zhi))将污(wu)(wu)染场地(di)地(di)下水环境污(wu)(wu)染风(feng)(feng)险(xian)等(deng)间距划分(fen)为(wei)以(yi)下3个等(deng)级：当(dang)R值(zhi)(zhi)为(wei)1～4分(fen)时(shi)，为(wei)低污(wu)(wu)染风(feng)(feng)险(xian)场地(di)；当(dang)R值(zhi)(zhi)为(wei)4～7分(fen)时(shi)，为(wei)中污(wu)(wu)染风(feng)(feng)险(xian)场地(di)；当(dang)R值(zhi)(zhi)为(wei)7～10分(fen)时(shi)，为(wei)高污(wu)(wu)染风(feng)(feng)险(xian)场地(di)。

2 评价指标筛选与风险分级评价方法的构建

2.1 评价指标筛选

2.1.1 污染源负荷和受体特征评价(jia)指标选取(qu)

污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)源(yuan)负荷(he)指(zhi)(zhi)标(biao)(biao)(biao)主(zhu)要(yao)描述污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)环(huan)境污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)的(de)严重程度，参考国(guo)内(nei)(nei)外污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)环(huan)境污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)等级(ji)评价(jia)系统(tong)中(zhong)的(de)指(zhi)(zhi)标(biao)(biao)(biao)，选取土(tu)壤(rang)(rang)污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)超标(biao)(biao)(biao)倍(bei)数、土(tu)壤(rang)(rang)污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)超标(biao)(biao)(biao)范(fan)围(wei)作(zuo)为污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)源(yuan)负荷(he)评价(jia)指(zhi)(zhi)标(biao)(biao)(biao)；受(shou)(shou)体(ti)(ti)特(te)征(zheng)(zheng)指(zhi)(zhi)标(biao)(biao)(biao)主(zhu)要(yao)反映(ying)受(shou)(shou)体(ti)(ti)的(de)易(yi)损性，主(zhu)要(yao)参考国(guo)内(nei)(nei)《关闭搬迁企业风险(xian)筛查与风险(xian)分(fen)级(ji)技术规定(试行)》中(zhong)的(de)指(zhi)(zhi)标(biao)(biao)(biao)，选取地(di)下水及邻(lin)近地(di)表水利用类型(xing)、场(chang)地(di)及周边500 m内(nei)(nei)人口(kou)数量、重点区域离最近敏感点距(ju)离作(zuo)为受(shou)(shou)体(ti)(ti)特(te)征(zheng)(zheng)指(zhi)(zhi)标(biao)(biao)(biao)。土(tu)壤(rang)(rang)污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)超标(biao)(biao)(biao)范(fan)围(wei)按最大污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)土(tu)壤(rang)(rang)方量计(ji)；土(tu)壤(rang)(rang)污(wu)(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)超标(biao)(biao)(biao)总倍(bei)数按下式计(ji)算：

(11)

式中(zhong)：P为(wei)土(tu)(tu)(tu)壤(rang)污(wu)染(ran)物超标总倍数(shu)(倍)；Ci为(wei)土(tu)(tu)(tu)壤(rang)中(zhong)第i个(ge)(ge)污(wu)染(ran)物浓度的实测值，取(qu)所有土(tu)(tu)(tu)壤(rang)样品(pin)测试数(shu)据中(zhong)的最高值(mg/kg);Coi为(wei)土(tu)(tu)(tu)壤(rang)中(zhong)第i个(ge)(ge)污(wu)染(ran)物浓度的标准值(mg/kg)，参考(kao)《土(tu)(tu)(tu)壤(rang)环境质量(liang) 建(jian)设(she)用地土(tu)(tu)(tu)壤(rang)污(wu)染(ran)风(feng)险管控(kong)标准(试行)》(GB 36600—2018)中(zhong)的筛选值；n为(wei)土(tu)(tu)(tu)壤(rang)中(zhong)污(wu)染(ran)物个(ge)(ge)数(shu)(个(ge)(ge))。

2.1.2 污染物释放可能性评价指标选取

局部(bu)灵(ling)(ling)敏(min)度(du)分(fen)析(xi)(xi)(xi)方法中参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)灵(ling)(ling)敏(min)度(du)会随参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)初(chu)始值(zhi)位置的(de)(de)变(bian)化有较(jiao)大(da)的(de)(de)波动，从而导(dao)致参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)灵(ling)(ling)敏(min)度(du)排序不稳定[30-31]，因此(ci)本研究选取(qu)区域(yu)灵(ling)(ling)敏(min)度(du)分(fen)析(xi)(xi)(xi)方法。根据区域(yu)灵(ling)(ling)敏(min)度(du)分(fen)析(xi)(xi)(xi)原理[32-33]，采用(yong)蒙特卡洛抽(chou)样方法在各参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)区间(jian)内(见(jian)表(biao)(biao)1)随机(ji)采样，计算(suan)每(mei)组参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)对应的(de)(de)输(shu)出结果，即土壤稀释衰减因子，并(bing)取(qu)输(shu)出结果的(de)(de)前5%所对应的(de)(de)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)作为(wei)可(ke)接受(shou)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)，利用(yong)K-S检验分(fen)析(xi)(xi)(xi)可(ke)接受(shou)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)分(fen)布(bu)与原始参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)分(fen)布(bu)的(de)(de)差异，两者(zhe)之间(jian)差异越大(da)表(biao)(biao)明(ming)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)的(de)(de)灵(ling)(ling)敏(min)度(du)越高。若(ruo)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)的(de)(de)显著(zhu)性(xing)水(shui)平小于0.05[26]，则认为(wei)参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)的(de)(de)灵(ling)(ling)敏(min)度(du)显著(zhu)。各参(can)(can)(can)数(shu)(shu)(shu)(shu)(shu)区域(yu)灵(ling)(ling)敏(min)度(du)分(fen)析(xi)(xi)(xi)结果，见(jian)表(biao)(biao)2。

表1 稀释(shi)衰减模型参数(shu)的(de)取值范围(wei)[34-36]

Table 1 Range of dulition attenuation model parameters[34-36]

表(biao)2 稀(xi)释衰减模(mo)型参(can)数K-S检验的统(tong)计量(liang)和显著(zhu)性水(shui)平(ping)

Table 2 K-S statisic of dulition attenuation model parameters

通过对比各参数(shu)(shu)的显著性(xing)水平，可得出灵敏度显著的参数(shu)(shu)有(you)污(wu)(wu)染物(wu)分配(pei)系数(shu)(shu)(lgKoc)、土壤(rang)水入渗(shen)速率(I)、一阶衰减(jian)常数(shu)(shu)(λ)、未污(wu)(wu)染土壤(rang)厚(hou)度(D)、土壤(rang)有(you)机碳含量(foc)。

2.2 评价指标权重的确定

首(shou)先，通过层(ceng)(ceng)次(ci)分析(xi)法建(jian)立污(wu)染(ran)场地(di)地(di)下水(shui)环境(jing)污(wu)染(ran)风险评(ping)价(jia)的(de)递阶(jie)层(ceng)(ceng)次(ci)结(jie)构，共(gong)分为三个层(ceng)(ceng)次(ci)，即目标(biao)层(ceng)(ceng)、准(zhun)则层(ceng)(ceng)和指标(biao)层(ceng)(ceng)；然后，结(jie)合污(wu)染(ran)物释放可能性(xing)评(ping)价(jia)指标(biao)的(de)灵(ling)敏(min)度分析(xi)结(jie)果，采用1～9标(biao)度法构造判断(duan)(duan)矩阵，以判断(duan)(duan)矩阵为基(ji)础计算判断(duan)(duan)矩阵的(de)特征(zheng)值及其(qi)对(dui)应的(de)特征(zheng)向(xiang)量(liang)，并将特征(zheng)向(xiang)量(liang)经归(gui)一(yi)化处(chu)理后，即可得到相应的(de)层(ceng)(ceng)次(ci)单元排(pai)序的(de)相对(dui)重(zhong)要(yao)性(xing)权重(zhong)；最后，使用最大特征(zheng)值和权重(zhong)向(xiang)量(liang)进行一(yi)致(zhi)性(xing)检验(yan)，由此计算出的(de)各评(ping)价(jia)指标(biao)的(de)权重(zhong)值，见表(biao)3。

表3 污染场地(di)地(di)下(xia)水环境污染风险评价指标的权(quan)重值

Table 3 Weight value of each risk evaluation index of groundwater pollution in contaminated site

2.3 评价指标分级与评分

污(wu)染(ran)源(yuan)负荷(he)评价指标(biao)主要参考美国、加(jia)拿大(da)等国家污(wu)染(ran)场(chang)地(di)环境(jing)污(wu)染(ran)风险(xian)(xian)分(fen)级分(fen)类(lei)系统中(zhong)的(de)指标(biao)分(fen)级；受(shou)体(ti)特征评价指标(biao)主要参考我国《关闭搬迁企业地(di)块(kuai)风险(xian)(xian)筛查(cha)与(yu)风险(xian)(xian)分(fen)级技(ji)术规定(试行(xing))》中(zhong)的(de)指标(biao)分(fen)级；污(wu)染(ran)物释(shi)放可能性指标(biao)主要参考DRASTIC及相关文(wen)献(xian)[5,12]中(zhong)的(de)指标(biao)分(fen)级。污(wu)染(ran)场(chang)地(di)地(di)下水环境(jing)污(wu)染(ran)风险(xian)(xian)各评价指标(biao)的(de)分(fen)级与(yu)评分(fen)情况，见(jian)表4和表5。

表4 污染场(chang)地(di)污染源(yuan)负荷和受体(ti)特征评价指标(biao)分(fen)级与(yu)赋分(fen)表

Table 4 Classification and scores of source load indexes and acceptor charateristic indexes in contaminated site

表5 污染场地污染物释放可能性评价指标分(fen)级与赋(fu)分(fen)表

Table 5 Classification and scores of pollutant release potential indexes in contaminated site

3 案例应用与分析

3.1 污染场地概况与评分

1）建筑物(wu)(wu)竖向布置：H1/H=34.5/98.4=0.35＞0.2；B1/B=17.5/39.5=0.0.44＜0.75。超限程度(du)：（0.75-0.44）/0.75×100%=41.3%。其中，H1为1～9层裙(qun)房(fang)高度(du)；H为建筑物(wu)(wu)总(zong)高度(du)；B1为标准层宽(kuan)度(du)；B为裙(qun)房(fang)宽(kuan)度(du)。

案(an)例一(yi)的(de)某铬(ge)盐厂主要生产重铬(ge)酸钠和(he)(he)(he)铬(ge)酸酐等铬(ge)系(xi)列产品，该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)土(tu)壤中(zhong)主要特(te)征污(wu)(wu)染物(wu)(wu)(wu)为(wei)(wei)六价(jia)铬(ge)(Cr6+)，由《土(tu)壤环境(jing)质量 建设用地(di)(di)(di)(di)土(tu)壤污(wu)(wu)染风(feng)险管(guan)控标(biao)(biao)准(试行(xing))》(GB 36600—2018)可(ke)知，第(di)二类(lei)用地(di)(di)(di)(di)土(tu)壤中(zhong)Cr6+的(de)筛选值为(wei)(wei)5.7 mg/kg，土(tu)壤中(zhong)Cr6+最(zui)大浓度值为(wei)(wei)811.57 mg/kg，按(an)(an)照公式(shi)(11)计算该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)污(wu)(wu)染物(wu)(wu)(wu)Cr6+的(de)超(chao)标(biao)(biao)倍数为(wei)(wei)142.38倍，污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)污(wu)(wu)染物(wu)(wu)(wu)Cr6+的(de)超(chao)标(biao)(biao)范围为(wei)(wei)2.98×104 m3；污(wu)(wu)染物(wu)(wu)(wu)释(shi)放可(ke)能性各(ge)评价(jia)指(zhi)标(biao)(biao)根据该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)实(shi)际(ji)调(diao)查报告取(qu)值，包括污(wu)(wu)染物(wu)(wu)(wu)分(fen)配(pei)系(xi)数、未污(wu)(wu)染土(tu)壤厚度、土(tu)壤水(shui)入渗速率、一(yi)阶衰减(jian)常数和(he)(he)(he)土(tu)壤有机(ji)碳含(han)量；该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)利用类(lei)型为(wei)(wei)居(ju)民(min)饮用水(shui)，场(chang)(chang)地(di)(di)(di)(di)及(ji)周边(bian)500 m内人口数量约(yue)为(wei)(wei)1 500人，场(chang)(chang)地(di)(di)(di)(di)最(zui)近敏感点为(wei)(wei)地(di)(di)(di)(di)表水(shui)，距场(chang)(chang)地(di)(di)(di)(di)距离为(wei)(wei)50 m。按(an)(an)照表4和(he)(he)(he)表5中(zhong)各(ge)评价(jia)指(zhi)标(biao)(biao)的(de)分(fen)级(ji)标(biao)(biao)准对该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)各(ge)评价(jia)指(zhi)标(biao)(biao)进行(xing)评分(fen)，得到该污(wu)(wu)染场(chang)(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水(shui)环境(jing)污(wu)(wu)染风(feng)险各(ge)评价(jia)指(zhi)标(biao)(biao)的(de)取(qu)值及(ji)评分(fen)结(jie)果，见表6。

表(biao)6 案例(li)一污染(ran)场地地下(xia)水(shui)环境(jing)污染(ran)风险评价(jia)指标评分结果

Table 6 Groundwater contamination risk score of case 1

案(an)例二的(de)(de)(de)某化学原(yuan)料(liao)和化学制品(pin)厂主要生产色酚(fen)AS、间苯二酚(fen)、涤纶树脂等产品(pin)，污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)主要来源于加工过程中(zhong)(zhong)原(yuan)料(liao)、半成品(pin)、成品(pin)的(de)(de)(de)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)，该(gai)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)土壤中(zhong)(zhong)主要特征(zheng)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物为(wei)苯、甲苯，土地(di)(di)利用(yong)(yong)类(lei)型为(wei)商(shang)业用(yong)(yong)地(di)(di)，由《土壤环(huan)境质量(liang) 建(jian)设用(yong)(yong)地(di)(di)土壤污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)管控标(biao)准(试行)》(GB 36600—2018)可知，第(di)二类(lei)用(yong)(yong)地(di)(di)土壤中(zhong)(zhong)苯、甲苯的(de)(de)(de)筛选(xuan)值(zhi)分别为(wei)4 mg/kg、1 200 mg/kg，按照公(gong)式(11)计(ji)算(suan)该(gai)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物的(de)(de)(de)超标(biao)倍(bei)数为(wei)6 659倍(bei)，污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物的(de)(de)(de)超标(biao)范(fan)围为(wei)1.35×104 m3；污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物释放可能(neng)性评(ping)(ping)价(jia)(jia)指标(biao)取(qu)值(zhi)情况见表(biao)(biao)7；该(gai)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)地(di)(di)下水利用(yong)(yong)类(lei)型为(wei)不开发(fa)，场(chang)(chang)(chang)(chang)地(di)(di)及周(zhou)边500 m内(nei)人(ren)口数量(liang)较少(shao)，约为(wei)300人(ren)，最近敏感点为(wei)居民区(qu)，距场(chang)(chang)(chang)(chang)地(di)(di)距离为(wei)400 m。按照表(biao)(biao)4和表(biao)(biao)5中(zhong)(zhong)各评(ping)(ping)价(jia)(jia)指标(biao)的(de)(de)(de)分级(ji)标(biao)准对该(gai)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)各评(ping)(ping)价(jia)(jia)指标(biao)进行评(ping)(ping)分，得到该(gai)污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)(chang)(chang)(chang)地(di)(di)地(di)(di)下水环(huan)境污(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)各评(ping)(ping)价(jia)(jia)指标(biao)的(de)(de)(de)取(qu)值(zhi)及评(ping)(ping)分结(jie)果，见表(biao)(biao)7。

表7 案例二污染场地地下(xia)水(shui)环境污染风险评(ping)价(jia)指(zhi)标评(ping)分(fen)结(jie)果(guo)

Table 7 Groundwater contamination risk score of case 2

3.2 评价结果与分析

根据表(biao)6和(he)表(biao)7中(zhong)(zhong)(zhong)(zhong)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)各(ge)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)指标(biao)(biao)的(de)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)分(fen)(fen)结(jie)果，按照公式(shi)(10)计算得到(dao)两个案(an)例(li)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)地(di)(di)(di)(di)(di)(di)(di)下水环(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)综合指数总分(fen)(fen)值分(fen)(fen)别为(wei)9.08分(fen)(fen)、6.35分(fen)(fen)。此外，采(cai)用(yong)(yong)《关闭搬迁(qian)(qian)企(qi)业(ye)地(di)(di)(di)(di)(di)(di)(di)块风险(xian)筛查与风险(xian)分(fen)(fen)级技(ji)术规(gui)定(ding)(试(shi)行)》中(zhong)(zhong)(zhong)(zhong)的(de)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)方法(fa)对(dui)其进行评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)，计算得到(dao)两个案(an)例(li)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)地(di)(di)(di)(di)(di)(di)(di)下水环(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)总分(fen)(fen)值分(fen)(fen)别为(wei)84.4分(fen)(fen)、68.9分(fen)(fen)。结(jie)果表(biao)明：采(cai)用(yong)(yong)本文评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)方法(fa)得到(dao)案(an)例(li)一(yi)(yi)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)为(wei)高污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)场(chang)地(di)(di)(di)(di)(di)(di)(di)，案(an)例(li)二污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)为(wei)中(zhong)(zhong)(zhong)(zhong)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)场(chang)地(di)(di)(di)(di)(di)(di)(di)。分(fen)(fen)析认为(wei)：案(an)例(li)一(yi)(yi)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)生(sheng)产活动(dong)时(shi)间(jian)较(jiao)长，多年粗放(fang)的(de)生(sheng)产方式(shi)导致(zhi)场(chang)地(di)(di)(di)(di)(di)(di)(di)土壤污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)严(yan)(yan)重，污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)源负荷(he)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)指标(biao)(biao)的(de)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)分(fen)(fen)值较(jiao)高，且(qie)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)距离居民生(sheng)活区较(jiao)近，将会对(dui)周围(wei)地(di)(di)(di)(di)(di)(di)(di)下水和(he)周边人群健康造成很大的(de)影响；案(an)例(li)二污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)土壤污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)虽然(ran)较(jiao)为(wei)严(yan)(yan)重，但土壤中(zhong)(zhong)(zhong)(zhong)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)(wu)迁(qian)(qian)移能力较(jiao)弱，地(di)(di)(di)(di)(di)(di)(di)下水为(wei)不利用(yong)(yong)，敏(min)感目标(biao)(biao)较(jiao)少，故该(gai)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)地(di)(di)(di)(di)(di)(di)(di)下水环(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)的(de)风险(xian)较(jiao)小。该(gai)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)结(jie)果与采(cai)用(yong)(yong)《关闭搬迁(qian)(qian)企(qi)业(ye)地(di)(di)(di)(di)(di)(di)(di)块风险(xian)筛查与风险(xian)分(fen)(fen)级技(ji)术规(gui)定(ding)(试(shi)行)》中(zhong)(zhong)(zhong)(zhong)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)方法(fa)的(de)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)结(jie)果基本一(yi)(yi)致(zhi)。另外，本文评(ping)(ping)(ping)(ping)(ping)(ping)(ping)介方法(fa)所选取的(de)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)指标(biao)(biao)包括污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)(wu)本身(shen)属性(xing)(xing)的(de)指标(biao)(biao)如污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)(wu)分(fen)(fen)配系数、一(yi)(yi)阶衰减常数等(deng)，适用(yong)(yong)于不同特征污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)物(wu)(wu)场(chang)地(di)(di)(di)(di)(di)(di)(di)地(di)(di)(di)(di)(di)(di)(di)下水环(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)的(de)风险(xian)评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)，并且(qie)可有(you)效地(di)(di)(di)(di)(di)(di)(di)减少评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)过程中(zhong)(zhong)(zhong)(zhong)的(de)主观性(xing)(xing)，从而验证了本文所构建的(de)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)场(chang)地(di)(di)(di)(di)(di)(di)(di)地(di)(di)(di)(di)(di)(di)(di)下水环(huan)境(jing)(jing)污(wu)(wu)(wu)(wu)(wu)(wu)染(ran)(ran)(ran)(ran)风险(xian)分(fen)(fen)析评(ping)(ping)(ping)(ping)(ping)(ping)(ping)价(jia)(jia)(jia)方法(fa)具有(you)合理性(xing)(xing)和(he)可靠性(xing)(xing)。

4 结论与建议

(1) 本文综合考虑污(wu)染源(yuan)负荷(he)、污(wu)染物释放(fang)可(ke)能(neng)性、受体特(te)征三个(ge)方(fang)面的因(yin)素，采用层次分析法和(he)灵敏度分析法构(gou)建了污(wu)染场地地下水环境污(wu)染风险分级评价方(fang)法，有效降低了建立评价指标体系(xi)时的主观性，可(ke)为环境管(guan)理部(bu)门提供理论依据及技术支撑。

(2) 运用本(ben)文(wen)所(suo)(suo)构(gou)建(jian)的(de)污(wu)(wu)(wu)染(ran)场(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水环(huan)境污(wu)(wu)(wu)染(ran)风(feng)险(xian)分级评价(jia)(jia)(jia)方(fang)法(fa)对两个典(dian)型案(an)例(li)污(wu)(wu)(wu)染(ran)场(chang)地(di)(di)(di)(di)地(di)(di)(di)(di)下(xia)水环(huan)境污(wu)(wu)(wu)染(ran)风(feng)险(xian)进(jin)行了(le)分级评价(jia)(jia)(jia)与验证(zheng)，结果表明(ming)：案(an)例(li)一污(wu)(wu)(wu)染(ran)场(chang)地(di)(di)(di)(di)为(wei)高污(wu)(wu)(wu)染(ran)风(feng)险(xian)场(chang)地(di)(di)(di)(di)，案(an)例(li)二污(wu)(wu)(wu)染(ran)场(chang)地(di)(di)(di)(di)为(wei)中(zhong)污(wu)(wu)(wu)染(ran)风(feng)险(xian)场(chang)地(di)(di)(di)(di)，该评价(jia)(jia)(jia)结果与现(xian)有(you)(you)评价(jia)(jia)(jia)方(fang)法(fa)的(de)评价(jia)(jia)(jia)结果基本(ben)一致，且本(ben)文(wen)构(gou)建(jian)的(de)评价(jia)(jia)(jia)方(fang)法(fa)更适用于不(bu)同(tong)特(te)征污(wu)(wu)(wu)染(ran)物场(chang)地(di)(di)(di)(di)的(de)地(di)(di)(di)(di)下(xia)水环(huan)境污(wu)(wu)(wu)染(ran)风(feng)险(xian)分级评价(jia)(jia)(jia)，从而(er)验证(zheng)了(le)本(ben)文(wen)所(suo)(suo)构(gou)建(jian)的(de)评价(jia)(jia)(jia)方(fang)法(fa)具有(you)(you)合理性和可靠性。

(3) 污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)环(huan)境(jing)污(wu)(wu)(wu)(wu)染(ran)风(feng)(feng)险的(de)(de)分(fen)(fen)级(ji)(ji)评(ping)(ping)价可以根据污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)环(huan)境(jing)危害的(de)(de)轻重缓急进行优先区分(fen)(fen)，以便(bian)对不同风(feng)(feng)险等级(ji)(ji)的(de)(de)污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)进行分(fen)(fen)类(lei)(lei)管理。国家层面的(de)(de)污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)环(huan)境(jing)污(wu)(wu)(wu)(wu)染(ran)风(feng)(feng)险分(fen)(fen)级(ji)(ji)分(fen)(fen)类(lei)(lei)评(ping)(ping)价体(ti)系的(de)(de)构建是一(yi)项长(zhang)期而(er)复杂的(de)(de)系统(tong)工(gong)程，建议借(jie)鉴国外(wai)发达国家已有的(de)(de)污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)环(huan)境(jing)污(wu)(wu)(wu)(wu)染(ran)风(feng)(feng)险分(fen)(fen)级(ji)(ji)分(fen)(fen)类(lei)(lei)评(ping)(ping)价体(ti)系，采用多(duo)(duo)种评(ping)(ping)价方法，并从多(duo)(duo)途径、多(duo)(duo)受体(ti)、多(duo)(duo)方面构建综合、全(quan)面、系统(tong)的(de)(de)污(wu)(wu)(wu)(wu)染(ran)场(chang)地(di)环(huan)境(jing)污(wu)(wu)(wu)(wu)染(ran)风(feng)(feng)险分(fen)(fen)级(ji)(ji)管理体(ti)系。

来源：土行者