造粒飞灰沥青混凝土路面利用的地下水环境风险评估

由于飞灰的主要成分与粉煤灰、高炉矿渣等非常接近,用于沥青混凝土路面中具有良好的发展前景。但飞灰中含有的重金属等有害物质对路面周围的环境影响不容忽视。通过对飞灰沥青混凝土采用水槽浸出试验得到重金属的长期累积释放量,并构建出重金属渗入地下水的迁移扩散模型,对道路中重金属进入地下水进行环境风险评估,最后根据《生活饮用水卫生标准》(GB5749—2006)推算出沥青混凝土路面中重金属的有效量限值。结果表明:As、Cr的致癌风险值分别为2.26×10^-10、2.33×10^-10,Zn、Cd、Hg的非致癌危害商分别为4.17×10^-7、2.43×10^-7、7.22×10^-6,分别未超过风险表征限值10^-6与1;造粒飞灰沥青混凝土路面中Cr、Zn、As、Cd、Hg的有效量限值分别为25.46、279.83、1.10、12.19、0.07mg/kg。

Environmental risk assessment of groundwater of granulated fly ash utilization on asphalt pavement

Municipal solid waste incineration fly ash can be applied in the asphalt pavement widely,since the similar components of municipal solid waste incineration fly ash,coal fly ash and blast furnace slag.However,the environmental risk of heavy metals from fly ash should be paid more attention.The long term leaching tests for cumulative amounts of heavy metals were conducted by tank leaching tests.And the migration and diffusion models of heavy metal infiltration into groundwater were established.The environmental risk assessment of heavy metals for the groundwater was carried out.Last but not least,the maximum availability amount of heavy metals in the pavement were calculated by“Standard for drinking water quality”(GB 5749-2006).The results showed that the carcinogenic risk values of As(2.26×10^-10)and Cr(2.33×10^-10)were lower than 10^-6.Meanwhile,the hazards of Zn,Cd and Hg were 4.17×10^-7,2.43×10^-7 and 7.22×10^-6,respectively,which did not exceed risk limit 1.The maximum availability amount of Cr,Zn,As,Cd and Hg in the asphalt pavement were 25.46,279.83,1.10,12.19,0.07 mg/kg,respectively.