Design of Watertight Barriers for Retention Ponds of Cyanide Using Sludge from Water Purification Station (Ziga)

David Y.K. Toguyeni, Fabien Yonli
2014 Journal of Materials Science and Engineering: B  
In a context of sustainable development and use of eco-materials, it was examined the possibility of using sewage sludge from the water treatment plant of Ziga as an inorganic support to achieve sealing barriers that can withstand high stresses to overcome any weaknesses of the geological barrier (called passive barrier). The station Ziga that potabilises the water from the river Nakambé is located 45 km north east of Ouagadougou. Some experiments on the rheology of sludge from Ziga as well as
more » ... om Ziga as well as the filtration of the mixture Ziga's sludge and clays from Nouna, Zorgho and Ticare, three regions of Burkina Faso, were conducted. These studies demonstrated the complex hydro-mechanical behavior of Ziga's slurries: Newtonian fluid thixotropic threshold for solids contents less than 16.5 wt% and non-Newtonian for higher values. Sludge from the water treatment station Ziga have a hydraulic conductivity of 10 -8 m/s. The results are below regulatory requirements. However, the permeability can be reduced to achieve the value of 10 -9 m/s in particular by adding the clay from Zorgho or Nouna to mixtures of Ziga's sludge and neutral leachate, typically mineral water. Beside neutral leachate, two types of leachate were used. One type is composed of acid leachate and the other type is basic. It was shown that the limewater solutions cause deterioration of the seal probably due to the presence of hydroxide ions.
doi:10.17265/2161-6221/2014.06.007 fatcat:6ch2bftxwvekzougcjgyuusw64