Potential Risk Related To The Reuse of Faecal Sludge In Agriculture: Proposal For An Ecological Treatment Method Based On Active Charcoal
Abstract This study is aimed at highlighting the risks associated with the reuse of faecal sludge and proposed a sustainable treatment method. The sampling consisted of collecting samples of faecal sludge in 5L of sterilized containers and then transporting to the laboratory in a refrigerated chamber for the determination of helminth eggs using standard protocols. The experimental device consisted of two replicates, one test and one control. The test samples received active charcoal at different concentrations (C1, C2, C3, C4, C5, C6). The physico-chemical parameters were measured before and after treatment. The samples were then observed under the optical microscope at the 40X objective for morphological identifications. Molecular analysis was carried out using the Polymerase Chain Reaction technique. The viability of the eggs were determined using incubation and staining techniques. Analyses showed that the sludge used for irrigation contained eggs and larvae of 6 helminth species (S. stercoralis, A. duodenale, N. americanus, T. trichiuria, H. nana and Ascaris spp.) with viability percentages ranging from 57.72% to 74.46%. Treatment with active charcoal allowed significant adsorption of these parasites with yields ranging from 95 to 100%. In addition, the carbon used has favoured the alkaline stabilisation of the medium, which increases its absorption potential. It can therefore be used in the treatment of sludge because, unlike other chemical disinfectants, it does not present any toxic effects.