Anaerobic degradation of landfill leachate using an upflow anaerobic fixed-bed reactor with microbial sulfate reduction

• Published in: Journal of hazardous materials Vol. 167; no. 1; pp. 1133 - 1140
• Main Authors: Thabet, Olfa Ben Dhia, Bouallagui, Hassib, Cayol, Jean-luc, Ollivier, Bernard, Fardeau, Marie-Laure, Hamdi, Moktar
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-08-2009; Elsevier
• Subjects: Anaerobic bioreactor; Anaerobiosis; Applied sciences; Bacteria; Bacteria, Anaerobic - metabolism; Biodegradation, Environmental; Biological and medical sciences; Bioreactors; Biotechnology; Chemical engineering; Clostridium; Clostridium - isolation & purification; Clostridium - metabolism; Crack opening displacement; Degradation; Desulfovibrio; Desulfovibrio - isolation & purification; Desulfovibrio - metabolism; Desulfovibrio desulfuricans; Desulfovibrio sp; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General treatment and storage processes; Hydrogen Sulfide; Landfill leachate; Landfills; Methods. Procedures. Technologies; Microorganisms; Others; Pollution; Reactors; Reduction; Strain; Sulfate reduction; Sulfate-reducing bacteria; Sulfates; Sulfates - metabolism; Various methods and equipments; Wastes; Water Pollutants, Chemical - metabolism; Sulfate reduction; Hydrogen sulfide; Anaerobic bioreactor; Sulfate-reducing bacteria; Desulfovibrio sp; Landfill leachate; Waste dumping; Similarity; Upward flow; Fixed bed reactor; Hydrogen sulfides; Sulfates; Retention time; Biological purification; Bioreactor; Anaerobe; Chemical oxygen demand; Production; Water quality; pH; Leachate
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.01.114

This study evaluated the anaerobic degradation of landfill leachate and sulfate reduction as a function of COD/(SO
4
2−) ratio in an upflow anaerobic fixed-bed reactor. The reactor, which was inoculated with a mixed consortium, was operated under a constant hydraulic retention time (HRT) of 5 days. We investigated the effect of COD/(SO
4
2−) ratio variation on the sulfate reduction efficiency, hydrogen sulfide production, chemical oxygen demand (COD) removal, conductivity, and pH variation. The best reactor performance, with significant sulfate reduction efficiency and COD removal efficiency of 91% and 87%, respectively, was reached under a COD/(SO
4
2−) ratio of 1.17. Under these conditions, microscopic analysis showed the abundance of vibrios and rod-shaped bacterial cells. Two anaerobic bacteria were isolated from the reactor sludge. Phylogenetic studies performed on these strains identified strain A1 as affiliated to
Clostridium genus and strain H1 as a new species of sulfate-reducing bacteria affiliated to the
Desulfovibrio genus. The closest phylogenetic relative of strain H1 was
Desulfovibrio desulfuricans, at 96% similarity for partial 16S RNA gene sequence data. Physiological and metabolic characterization was performed for this strain.