Physicochemical characterization of the sludge generated by the wastewater treatment plant of Kenitra

Abstract

The autonomous company of Kenitra "RAK", adopts the vision of valorization of the dehydrated sludge in the field of agriculture, if it meets the requirements. For that we studied the feasibility of this valorization via a physicochemical study; the parameters which were studied are: Dry matter (DM) and volatile dry matter (VDM), pH, dryness, the detection of fertilizing elements and heavy metals. The results of physico-chemical analysis showed that the sludge from the wastewater treatment plant (WWTP) is rich in fertilizing elements such as: TKN (46mg/kg), Total Phosphorus (733mg/kg), Potassium (159.75mg/kg), and DM (31.11g/l), VDM (16.77g/l), pH (8.11), dryness (22.36%). For the heavy metal analysis, it is found that the sludge is in conformity with the standards of spreading in terms of heavy metal content (Cd 0,22mg/kg MS, Cr 106,27mg/kg MS, Cu 37,48 mg/Kg MS, Hg 1,33mg/Kg MS, Ni 7,66mg/Kg MS, Pb 12,75mg/Kg MS); It can be said that this sewage sludge from the Kenitra WWTP has a real agronomic interest but with the absence of a microbiological analysis of this sludge, it is impossible to make a decision concerning the use of the sludge in agriculture. The study conducted therefore requires further research to confirm the feasibility of recovery to benefit from a green fertilizer and reduce a certain pollution.