The quantity of waste generated in Libya, as in other developing countries, has
been increasing dramatically for many years due to a rapid urban expansion
associated with high population growth. Until now, this waste has been dumped
into very large open tip sites located close to urban areas. These sites lack any
form of engineered control system to prevent groundwater contamination and
environmental degradation from the air and ground pollution. A high risk of
groundwater contamination occurs in many water wells around the dumping
sites. There is an urgent need to fmd an affordable and feasible long-term
solution to protect groundwater supplies and the surrounding environment.
However, the construction of engineered landfills usually requires the
installation of a lining system. To be efficient, the lining system material should
have a low hydraulic conductivity that should not increase under the action of
leachates. This research provides a comprehensive physical and chemical
laboratory investigation of an arid Libyan soil to assess its suitability in a
landfill lining system. The clay mineralogy tested using XRD showed that
compositions of all soil types tested are similar and are predominately illite and
kaolinite. Batch equilibrinm testes were used to characterise the soil adsorption
properties. The results of this assessment indicate that Libyan clays is not
wholly satisfactory according to the criteria and guidelines available for landfill
mineral liners. However, a bentonite was used to improve Libyan soils'
performance as landfill liner. The results showed that bentonite improved the
engineering characteristics of the Libyan soils tested, and proved to be a better
additive as it lowered the hydraulic conductivity, and increased the adsorption
capacity of the soils. Bentonite thus showed that it has the potential of being
used as an additive to Libyan soils to improve its containment qualities.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.