摘要
固体废弃物填埋场通常需要在底部设置衬层来控制渗滤液渗漏所产生的二次污染问题。固化污泥是一种新型填埋场底部衬层材料,了解该低渗透性衬层材料对渗滤液中污染物的延迟阻滞作用,需要确定各污染物在其中随渗滤液迁移时的水动力弥散特性参数。针对固化污泥等低渗透性衬层材料水动力弥散参数试验和求解的问题,以填埋场渗滤液中F和Cr为代表,采用改进的柔性壁渗透试验来测定污染物水动力弥散时的浓度穿透曲线,并根据所获得的浓度穿透曲线,利用推导出的水动力弥散参数确定公式,得到了F和Cr随水迁移的水动力弥散参数、纵横向弥散度、阻滞系数、分配系数及有效孔隙度等指标。
The paper is to introduce its author＇s idea on how to solve the problem of the permeability of liner layer and prevent the contam- ination of the pollutant leakage by using the solidified sludge. As is known, it remains impossible to obtain hydrodynamic dispersion pa- rameters of the sludge solidified layer with low permeability by means of the currently existing column tests and methods. To solve the above problem, we do believe that it is necessary to improve ：he flexible wall parameter and overcome the breakthrough curve of F and Cr as the typical representative dispersion parameters of the contaminants. Otherwise, the leakage of the liner layer would happe-, and, in turn, the secondary time of pollution and contaminatior would be likely to come out. Therefore, as a result of our research, the solidi- fied sludge can be a new kind of liner material which can be made to satisfy the need for blocking or inhibiting the leaking effects. Further efforts are needed to make clear the likely tendency of the migration or transportation of leakage contaminants in the blocking layer as well as verify the hydrodynamic dispersion parameters with the hydrodynamic dispersion parameters. Based on the breakthrough curve of F and Cr we have worked out the hydrodynamic dispersion parameters via a set of derived formulas. According to our cxpcriment results, we have obtained the transference velocity of Cr, which is slower than that of F for more time is needed for the same concentration of F and Cr. On the other hand, the breakthrough curves of F and Cr have no relevance to the migration and pollutant transference path length. In the early and final stage of transportation, the transference velocity is slower, but in the middle period, the velocity becomes faster. The said parameters have been obtained, which are endowed with longitudinal measurement, horizontal measurement, delay coeffcient, distribution coefficient and valid pore size. As shown in the results, some parameters of F may have higher values than ones of Cr, such as hydrodynamic dispersion parameter, longitudinal measurement and horizontal measurement. But, for delay coefficient and distribution coefficient, the corresponding parameters of F may have lower values than those of Cr. Thus, it can be seen that the methods and results in the paper can help to determine the hydrodynamic dispersion parameters of materials with low permeability, for example, the solidified sludge. When determinating the hydrodymic dispersion parameters by using the aforementioned flexible wall parameters, it is only convection, dispersion, adsorption, desorption and simple chemical component that should be taken into account, with the exception of the biodegradation and radioactive decay of the elements involved.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2014年第5期201-205,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51178107
51378327)
住建部项目(2013-k4-51)
关键词
环境工程学
水动力弥散
固废填埋场
氟
CR
迁移
environmental engineering
hydrodynamic dispersion
solid waste landfill site
F
Cr
transference
