燃煤灰渣中砷的连续柱淋滤特性及表生运移作用初探  

Discussion on the leaching features of continuous column of arsenic in coal ash and the supergene migration

作　　者：傅丛 白向飞 连进京 

机构地区：[1]煤炭科学技术研究院有限公司煤化工分院,北京100013 [2]煤炭资源高效开采与洁净利用国家重点实验室,北京100013

出　　处：《煤质技术》2016年第2期53-59,共7页Coal Quality Technology

基　　金：质检公益性作业专项基金资助项目(10-190)

摘　　要：采用连续柱淋滤试验装置对高砷煤燃烧灰渣进行动态淋滤实验研究,用模拟酸雨淋溶土柱的试验方法探讨煤及燃煤灰渣对土壤的污染及表生运移作用,重点研究燃煤灰渣在不同酸度模拟酸雨条件下对污染土壤中重金属元素砷的淋滤液性质影响。高砷煤燃煤灰渣的动态淋滤实验表明,灰渣淋滤受体系、pH值、吸附和共沉淀作用等因素的影响,高砷及中砷煤灰在淋滤初期其砷的阶段淋滤浓度升幅均较大,但不同的煤灰出现砷淋滤浓度高峰值的时间点有所不同。针对同一燃煤灰渣,淋滤液酸性越强,灰渣中砷的阶段淋滤浓度相对较大,但均属弱淋滤强度。模拟酸雨作用于土壤之上的煤样或灰渣时,随着模拟酸雨酸性的增强,其淋滤液中砷的阶段淋滤率呈递增趋势;中砷灰或中砷煤中砷的阶段淋滤率和60 h总淋滤率分别小于0.5%、2%,属弱淋滤强度。淋滤液的酸性越强,煤及其燃烧灰渣在堆积过程中对土样中渗透砷含量的能力越高。含砷量较高的煤及其燃烧灰渣在堆积或利用过程中通过雨水等自然界长期淋滤作用有可能产生砷危害的累积效应。The dynamic leaching experiment of high arsenic coal combustion ash was studied bu using the continuous column leaching test device,the experimental method of soil column leaching using simulating acid rain was adopted to discuss the pollution of soil from coal and fire coal ash and the supergene migration effect,and research how the coal combustion ash affected the leaching liquid property of heavy metal element As in the polluted soil under the conditions of different acidity of simulating acid rain.The dynamic leaching experiment of high arsenic coal ash showed that the high arsenic coal ash leaching was affected by elements such as the system,pH value,adsorption and coprecipitation and so on,at the early stage of leaching,arsenic leaching concentration of high arsenic coal ash and middle arsenic coal ash increased dramatically,but the different high arsenic coal had different time points when peaks of leaching concentration appeared.Regarding to one type of coal combustion ash,when leaching liquid had stronger acidity,the stage leaching concentration of As in coal ash would be relatively high,but they all belonged to the weak leaching strength.When the simulating acid rain acted on the coal sample or ash on the soil,with the enhancement of simulating acid rain acidity,the stage leaching rate of As in the leaching liquid increased;stage leaching rate and 60 h total leaching rate of middle arsenic coal ash or As in middle arsenic coal were smaller than 0.5%,2%respectively,they belonged to weak leaching strength.When leaching liquid had stronger acidity,in the accumulating process,coal and arsenic coal combustion ash had higher ability to permeate the arsenic into the soil sample,in the process of accumulating or utilizing,high arsenic coal and its combustion ash could create the accumulative effect of arsenic hazard through long term leaching effect in natural world such as rain.

关 键 词：燃煤灰渣 砷 连续柱淋滤 淋滤特性 表生运移作用 阶段淋滤浓度 

分 类 号：TQ534[化学工程—煤化学工程] P595[天文地球—地球化学]