摘要
道路充填材料是油气开采废物脱油残渣(OCDRs)资源化的重要途径.现有资源化风险评估和管控主要基于简化模型,且未考虑区域风险差异,难以精准表征黄河流域OCDRs道路利用的环境风险及时空差异.本研究联合运用淋溶模拟实验、源强指数衰减模型和污染物瞬态迁移扩散模型,结合Monte Carlo方法对黄河流域OCDRs路基充填条件下的风险、管控限值及区域差异开展研究.结果表明:黄河流域Cu等6种重金属的实际累积释放量大都在常规浸出方法的1%~10%左右,但部分重金属的淋溶浓度峰值高于醋酸缓冲溶液法(HJ/T 300-2007《固体废物浸出毒性浸出方法醋酸缓冲溶液法》)、硫酸硝酸法(HJ/T299-2007《固体废物浸出毒性浸出方法硫酸硝酸法》)、水平振荡法(HJ 557-2010《固体废物浸出毒性浸出方法水平振荡法》)得到的浸出浓度.风险精细评估结果表明,OCDRs在黄河流域各省区道路利用条件下暴露点浓度超标概率为0,暴露浓度(95%分位值)低于地下水Ⅲ类水质限值(GB/T 14848-2017《地下水质量标准》),风险可接受;以浸出浓度为源强预测Pb的暴露浓度是地下水Ⅲ类水质限值的4.1倍,风险估计过高.沿黄9省区污染风险差异较大,暴露浓度最大相差41.46倍(Ba);管控限值相差更大,最大值省份(宁夏回族自治区)与最小值省份(四川省)相差近50倍(Zn).对比现行的鉴别标准,计算的各污染物风险管控限值大部分低于《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3-2007)限值,高于Ⅰ类固废限值,但个别省份(如宁夏回族自治区)管控限值高于GB 5085.3-2007限值.研究显示,传统浸出和风险评估方法体系对OCDRs中污染物的释放潜力和污染风险存在高估,亟待国家层面完善固废资源化风险评估和管控方法标准体系;同时,不同区域风险及管控限值差异较大,应对其中有害物质采取差异化管控要求.
Road filling materials are an important way to resourceise oil and gas extraction waste deoiled residues(OCDRs).Existing risk assessment and control of resourcing are mainly based on simplified models and do not take regional risk differences into account,making it difficult to accurately characterize the environmental risks and spatial and temporal differences of road use of OCDRs in the Yellow River Basin.In this study,the risk,control limits and regional differences of OCDRs roadbed filling conditions in the Yellow River Basin were investigated by using leaching simulation experiments,source strength exponential attenuation model and pollutant transient transport and diffusion model,combined with the Monte Carlo method.The results showed that the actual cumulative releases of six heavy metals,including Cu,in the Yellow River Basin,is mostly around 1%to 10%of the conventional leaching methods.but the peak leaching concentrations of some heavy metals were higher than those of the acetic acid buffer solution method(Solid Waste-Extraction Procedure for Leaching Toxicity-Acetic Acid Buffer Solution Method(HJ/T 300-2007)),sulphuric acid&nitric acid method(Solid Waste-Extraction Procedure for Leaching Toxicity-Sulphuric Acid&Nitric Acid Method(HJ/T 299-2007)),horizontal vibration method(Solid Waste-Extraction Procedure for Leaching Toxicity-Sulphuric Acid&Nitric Acid Method(HJ 557-2010)).The results of risk fine assessment showed that the probability of exceeding the concentration of OCDRs at the exposure point under the conditions of road utilization in the Yellow River Basin provinces is 0,and the exposure concentration(95%quantile value)is lower than the limit value of ClassⅢwater quality of groundwater(Standard for Groundwater Quality(GB/T 14848-2017)),and the risk is acceptable.Acceptable;the exposure concentration of Pb predicted by using leaching concentration as the source strength is 4.1 times of the water quality limit value of groundwaterⅢ,and the risk is overestimated.Pollution risk varied greatly among the nine provinces along the Yellow River,with a maximum difference in exposure concentration of 41.46 times(Ba);control limits varied even more,with a difference of nearly 50 times(Zn)between the provinces with the maximum value(Ningxia Hui Autonomous Region)and the province with the minimum value(Sichuan Province).Comparing with the current identification standards,most of the calculated risk control limits for each pollutant are lower than the limit values of Hazardous Waste Identification Standards for Leaching Toxicity Identification(GB 5085.3-2007),and higher than the limit values of ClassⅠsolid wastes,but the control limits for individual provinces(e.g.,Ningxia Hui Autonomous Region)are higher than the limit values of GB 5085.3-2007.Limit value.The study shows that the traditional leaching and risk assessment methodology system overestimates the release potential and pollution risk of pollutants in OCDRs,and there is an urgent need to improve the risk assessment and control methodology standard system for solid waste resources at the national level;at the same time,there are large differences in the risk and control limits in different regions,and differentiated control requirements should be adopted for the hazardous substances therein.
作者
李淑
徐亚
赵玉鑫
刘玉强
孙淑娜
LI Shu;XU Ya;ZHAO Yuxin;LIU Yuqiang;SUN Shuna(State Key Laboratory of Environmental Criteria and Risk Assessment,Research Institute of Solid Waste Management,Chinese Research Academy of Environment Sciences,Beijing 100012,China;School of Municipal and Environmental Engineering,Jilin Jianzhu University,Changchun 130118,China;Gansu Key Laboratory of Industrial Waste Recycling and Regulation,Lanzhou 730000,China)
出处
《环境科学研究》
CSCD
北大核心
2024年第1期160-170,共11页
Research of Environmental Sciences
基金
黄河流域生态保护和高质量发展联合研究项目(No.2022YRUC010303)
重点设施设备隐蔽渗漏快速响应与预防研究项目(No.2023YFC3708902)。
关键词
脱油废物
资源化
区域差异
风险管控
oil and gas extraction wastes
resourcing
regional differences
risk management
