Evaluation of effluents from bench-scale treatment combinations for landfill leachate in Ibadan, Nigeria

• Published in: Waste management & research Vol. 32; no. 1; pp. 70 - 78
• Main Authors: Aluko, Olufemi Oludare, Sridhar, MKC
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2014; Sage Publications Ltd
• Subjects: Ammonia; Artificial wetlands; Biological Oxygen Demand Analysis; Bioreactors; Chemical oxygen demand; Effluents; Landfill; Leachates; Nigeria; Nitrates; Nutrient removal; Pollutants; Studies; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Pollution - prevention & control; Water Purification - economics; Water Purification - instrumentation; Water Purification - methods; Water treatment; Wetlands; Nigeria; Ibadan Nigeria; Nigeria, Ibadan; effluent quality; Nigeria; Landfill leachate; discharge regulatory standards; combined treatment methods
• ISSN: 0734-242X; 1096-3669
• DOI: 10.1177/0734242X13514624

The removal of pollutants in landfill leachate was investigated using constructed wetlands, a trickling filter, alum flocculation and coagulation, and a sequencing batch reactor in various combinations. Thirteen combined operations were investigated involving three out of the four unit treatment methods in series. The study was conducted because unit operations, though achieved reductions in pollutants concentrations had effluent values above the national regulatory guideline values. The suspended solids of effluents were permissible in most treatment processes, while reductions in 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and ammonia (NH3) of leachates ranged from 80% to 97%; 86% to 97% and 92% to 98% respectively. However, there were significant increases in nitrate (85%) and dissolved oxygen of treatment (218%). In addition, the characteristics of the recommended treatment sequence, involving constructed wetlands, alum and trickling filter produced effluents with reductions in colour (97%), alkalinity (97%), BOD (97%), COD (97%) and NH3 (98%), and in metals, except nickel (29% reduction from the influent values). The recommended treatment combination is suitable for effective leachate management at the landfill. The cost of constructing and operating the recommended treatment combination at the facility, for 5 years, would be NGN6,009,750.00 ($38,036.39). The performance should be monitored on site prior to full adoption if effluent characteristics remain consistently low over dry and wet seasons.