Treatment of Leachate from the Technical Landfill Centre Aïn Defla (Algeria) by Oxidation and Biosorption Process

Abstract

The aim of this study was the treatment of leachate from the Technical Landfill Centre Aïn Defla in Algeria, which presents a serious threat to the environment. Elimination of organic matter (expressed as chemical oxygen demand (COD) and biological oxygen demand (BOD5)), suspended matter (SM), mineral matter (phosphates and ammoniacal nitrogen), and heavy metals (zinc and iron) were experimentally studied using the coupling of oxidation (OP) and biosorption processes (BS). The analysis results showed that the leachate studied at pH 8.8 was very loaded in organic matter (turbidity of 553 NTU, SM = 820 mg l−1, COD = 9669 mg O2 l−1, and BOD5 = 8875 mg O2 l−1), in salts (EC = 19.4 mS cm−1), in ammoniacal nitrogen (2027 mg l−1), in phosphates (22.9 mg l−1), and in sulphates (750 mg l−1). It also contained significant amounts of heavy metals, notably zinc (4.21 mg l−1) and iron (47.5 mg l−1). The evolution of the physicochemical parameters during the treatment showed that, under the optimal conditions (T = 45 °C, [H2O2] = 1.6 mol l−1, volume fraction φ(H2O2) = 5 %, and [Fe3+] = 0.5 mmol l−1), the reduction in COD was about 99 %, the reduction in BOD5 was 100 %, the elimination of colloidal particles (SM) could reach 95 %, reduction in phosphates was 78 %, reduction in ammonium was 98 %, reduction in sulphates was 96 %, reduction in zinc was 92 %, and the reduction in iron was 98 %.

Keywords

• leachate
• landfill
• oxidation process
• biosorption