摘要
为研究不同加湿水类型和填埋方式对稳定化飞灰水分迁移和污染物浸出的影响,建立“去离子水+摊铺式填埋”(FL)、“去离子水+吨袋填埋”(FBL)和“膜浓缩液+摊铺式填埋”(FCL)3个飞灰填埋柱,采用模拟酸雨淋滤150 d。结果显示,FL柱、FBL柱、FCL柱产渗时间依次为试验开始后的第60 d、73 d和68 d。FBL柱产渗时间最晚的原因主要是吨袋填埋提高了飞灰的持水能力。试验期间,FL柱、FBL柱、FCL柱在40 cm处均出现了可溶盐的积累,FCL柱由于采用膜浓缩液为加湿水,渗滤液中化学需氧量(COD)、氨氮(NH_3-N)浸出质量浓度的平均值分别比FL柱高31.55%和242.08%;试验结束时,FL柱、FBL柱、FCL柱Pb浸出总量依次为334.73 mg、327.62 mg和349.04 mg。FCL柱Pb浸出总量最高的主要原因是膜浓缩液携带的外源污染和膜浓缩液吸附/络合Pb在浸出过程中会重新溶出。研究成果可为飞灰填埋处置的环境安全提供依据。
The purpose of this paper is to study the effects of different humidified water types and landfill patterns on water migration and pollutants leaching from stabilized municipal solid waste incineration(MSWI) fly ash. To achieve this goal, three MSWI fly ash landfill columns with 75 cm total height and 20 cm diameter, composed of deionized water+ paving landfill(FL), deionized water + ton-bag landfill(FBL), and membrane concentration leachate + paving landfill(FCL) respectively were set up, leached using simulated acid rain which pH is 5.6 for 150 d. The results showed that the FL columns, FBL columns, and FCL columns produced leachate at 60 d, 73 d, and 68 d respectively after the start of the experiment. FBL column produced leachate at the latest was mainly due to the increasing water-holding capacity of the stabilized MSWI fly ash when it was wrapped in a ton-bag. During the experiment, accumulation of soluble salt in the MSWI fly ash was observed at 40 cm in the FL columns, FBL columns, and FCL columns, and the average COD and NH_3-N leaching mass concentrations in the leachate were 31.55% and 242.08% higher in the FCL column than that in the FL column, which was due to membrane concentrate leachate being used as humidified water. Until the end of the experiment, the total amount of Pb leached from the FL columns, FBL columns, and FCL columns were 334.73 mg, 327.62 mg, and 349.04 mg respectively. The highest total amount of Pb leached from the FCL column was mainly reasoned by the exogenous pollutants carried by the membrane concentrate leachate and re-dissolution of Pb that adsorbed/complexed by the membrane concentrate leachate when MSWI fly ash stabilized. The research findings of the study could provide a basis for the safe disposal of MSWI fly ash in landfills.
作者
刘建
冯艳平
牟陈亚
LIU Jian;FENG Yanping;MOU Chenya(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 610000,China;The IT Electronics Eleventh Design&Research Institute Scientific and Technological Engineering Corporation Limited,Chengdu 610000,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2023年第7期2497-2504,共8页
Journal of Safety and Environment
基金
国家自然科学基金项目(41602241)
四川省重大科技专项(2019YFS0509)。
关键词
环境工程学
飞灰
填埋
膜浓缩液
重金属
environmental engineering
fly ash
landill
membranted concentrated leachate
heavy metal
