期刊名称：The Open Environmental Pollution & Toxicology Journal
电子版ISSN：1876-3979
出版年度：2009
卷号：1
页码：18-26
DOI：10.2174/1876397900901010018
出版社：Bentham open
摘要：
Point sources such as landfills, can release high concentrations
of contaminants into the groundwater because of migration of leachate
from its bottom, which is generated primarily as a result of precipitation
falling on an active landfill surface, leaching out the potential
organic and inorganic contaminants from landfilled waste and discharging
the same to groundwater in underlying aquifer. Leachate from young
landfills has high dissolved solids content as well as a high concentration
of organic matter. Landfill leachate has the potential to contaminate
the surrounding environment and impair groundwater use. Organic
contaminants in landfill leachate originate from incoming wastes
or are produced as a result of biochemical reactions taking place
in landfills. To protect the groundwater from contamination by landfill
leachate, it is quite essential to provide the bottom barrier of
suitable thickness, and to minimize the amount of water that could
enter the landfill to create leachate. The present study was undertaken
to determine the rate of movement of potential contaminants from
its bottom to the aquifer media, so as to evolve a rational method
for the determination of thickness of bottom barrier on sound engineering
practice, in place of adopting a prescriptive standard, which is
very common in most of the Asian countries. The study was undertaken
for non conservative contaminant Dissolved Organic Carbon (DOC).
The governing equation of contaminant transport was solved using
finite difference method, and finite mass boundary condition to
ape the finite mass of contaminants in a landfill. The solution
of the model was run in MatLab 7.0 for a range of Darcy velocities
and retardation factors for a representative equivalent height of
leachate. Design curves were drawn which can be used for determination
of suitable barrier thickness on the basis of expected maximum concentration
of DOC in landfill leachate and maximum permissible concentration
of the same.
