Diagnosis of leachate from a closed landfill, impact on the soil, and treatment by coagulation flocculation with alginate and ferric chloride

This aim of study is to assess the diagnosis of leachate impacts on the soil of the closed landfill of the city of Mohammedia for several years and the treatment of these releases by coagulation–flocculation with a liquid effluent rich in FeCl 3 rejected by a company of steel (Maghreb STEEL) and also by alginate produced less expensive. Indeed, the leachate generated from closed dumping site at MESBAHIATE (Mohammedia, Morocco) was investigated. This leachate is characterized by a high chemical oxygen demand (COD) content which varies around 3,000 mg/L, a Kjeldahl total nitrogen concentration varying around 1,500 mg/L whereas the content in ammonium has a concentration of 960 mg/L. In addition, the BOD 5 /COD ratio is much less than 0.2, which indicates that the organic matter is not easily biodegradable, and subsequently justifies the use of physico-chemical treatments such as coagulation–flocculation. In order to monitor the leachate treatment by coagulation flocculation, several parameters were analyzed including: the turbidity, the COD, and the volume of the sludge decanted. The results showed that coagulation–flocculation by ferric chloride and alginate were very effective for reducing turbidity. This reduction reaches 95% and 86% for FeCl 3 and Alginate, respectively. The removal of COD by FeCl 3 30% and Alginate showed yields of 67% and 60%, respectively at optimal concentrations of 120 and 2,500 mg/L, respectively, for Alginate and FeCl 3 30%.