The aim of this research is to find substitute barrier materials for
natural clay from two kinds of municipal sludge: waterworks sludge
(S
$_w$
) and dredging sludge (S
$_d$
).
Laboratory tests were performed first to determine their Atterberg limits and
hydraulic conductivity. Based on the results, recommendation of using
waterworks sludge is proposed. Then, shear strength test was performed and we
found the shear resistance property of waterworks sludge is strong enough to
keep slope stability. In order to evaluate the possibility of secondary
pollution, we further determined the heavy metal contents of waterworks sludge
and the result shows that secondary pollution is less possible to happen.
Finally, economic analysis proves that reusing waterworks sludge as barrier
will save a great amount of money for both landfill and waterworks. At the end
of this article, we offer the proposal to use waterworks sludge and suggest a
further long-term simulated landfill test.
