Evaluation of a coagulation-flocculation process for the treatment of leachates using a biopolymer extracted from organic waste from the Opuntia ficus industry

Abstract

The aim of this research was evaluated the coagulant effect of three extractions of mucilage from Opuntia ficus waste on the contaminating material present in leachates from stage III of the Bordo Poniente Landfill located in Mexico City. Raw leachate samples were characterized. Optimal coagulation-flocculation conditions were determined by varying the quantity of coagulant and flocculant and modifying the pH of the medium. The efficiency of the coagulants to remove suspended solids, color and COD was evaluated under the determined optimal conditions. Moreover, optimal pH conditions and quantity of adsorbent were established for the three adsorbents synthesized and their efficiency to remove suspended solids, color and COD was evaluated by means of batch experiments. According to their characterization, leachates present in stage III of RSBP are between mature and intermediate leachates. At pH 6.5, using 3 grams of flocculant and 1 gram of Powder coagulant, the coagulation-flocculation tests showed a 46% (1300 mg / L) COD removal efficiency. The optimal for the removal of suspended solids and color were determined to be pH 2.0 with 3.0 grams of flocculant, reaching 64.4% (47 NTU) and 69.5% (1370 Pt-Co U). The optimal dose of the raw coagulants was 15 grams, while the dose of powder coagulant was 1.5 grams. The coagulation-flocculation conditions for the removal of suspended solids and color were determined to be pH 2.0 with 3.0 grams of flocculant, reaching 64.4% (47 NTU) turbidity removal and 69.5% color removal (1370 Pt-Co U), the COD removal was obtained at pH 6.5