固体废物沥青路面利用的环境风险评估

固体废物用于沥青路面建设具有广阔的发展前景,但由于固体废物中含有重金属等有害物质,其作为沥青路面利用的首要前提是环境安全。概述了沥青路面建设中固体废物的主要利用方式和现状,总结了固体废物中的有害物质在道路利用时造成的地下水和大气环境风险的评估方法,并介绍了常用于固体废物和水泥混凝土中重金属的浸出方法。通过总结沥青-集料的黏附性机理,以及目前固体废物道路利用中的重金属浸出方法,讨论了固体废物沥青路面利用环境风险评估中污染物释放的定量表征方法(浸出方法)的适宜性。结果表明:由于缺乏针对特定场景污染物浸出方法的研究,固体废物道路利用的环境风险评价只能通过实验室模拟和借鉴国外模型的方法进行。因此,固体废物沥青路面利用污染物的浸出方法应还原实际应用场景,需考虑车轮荷载、紫外线照射等因素。指出未来的研究方向为制定针对固体废物再利用领域的环境风险评价标准。

Progress on environmental risk assessment on solid wastes utilized in asphalt pavement

There are broad development prospects for solid waste utilization in the construction of asphalt pavement. As solid wastes may contain heavy metals and other contaminants, the environmental safety is the primary premise of their applications in asphalt pavement. The main utilization modes and current situations of solid wastes in asphalt pavement construction were reviewed. Meanwhile, the research methods of environmental risk assessment of the contaminants in the solid wastes in road use on the groundwater and atmosphere were summarized, and the common leaching methods of heavy metals in solid wastes and cement and concrete introduced. Based on a summary of the mechanism of asphalt-aggregate adhesion and the current heavy metal leaching methods in the use of solid wastes in pavement, the suitability of the quantitative characterization method (leaching method) of pollutants release in the environmental risk assessment of solid wastes utilization in asphalt pavement was discussed. It is concluded that the environmental risk assessment of solid waste pavement can be carried out only by laboratory simulation and in foreign models due to the lack of research on the leaching methods of pollutants in specific scenes. Therefore, the pollutant leaching methods for solid waste use in asphalt pavement should restore actual application scenarios, taking into account the wheel load, ultraviolet radiation and other factors. Finally, it is pointed out that the development of environmental risk assessment standards for solid waste recycling should be the future research trend.