Hydrologie : recherche actuelle

Characteristics and Biological Treatment of Leachates from a Domestic Landfill

Abstract

Saidi Neila, Khiari L,Kouki Soulwene, Ben Yahmed Amira, Ben Rejeb Asma,Fumio Murano and Kinnedy Ann

Waste material from urban areas is a major environmental concern and landfill application is a frequent method for waste disposal. The leachate from landfills can, however, negatively affect the surrounding environment. A bioreactor cascade containing submerged biofilms was used to treat newly formed (< 1 year old) leachates of the Jbel Chekir landfill located southwest of Tunis, Tunisia. A preliminary analysis indicated a highly biodegradable portion of the leachate substances (BOD5/ COD = 0.4). The treatment system and performance was investigated at different organic loading rates. Results obtained during this study indicated a significant reduction in organic matter between 60 to 90% of Total Organic Carbon. The main bacterial genera responsible for removal of organic carbon in the leachate consisted of the genera Bacillus, Actinomyces, Pseudomonas and Burkholderia. The bacterial isolates inoculated into raw leachates further reduced TOC concentrations. TOC was reduced by Pseudomonas isolates by 70%. Actinomyces and Bacillus isolates reduced TOC by 69% and Burkholderia isolates resulted in the greatest TOC reduction of 77%. Consortia of the bacterial isolates reached TOC yield of about 84%.