Evaluation of coagulation-flocculation and nanofiltration processes in landfill leachate treatment

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Toxic/hazardous substances & environmental engineering, 2019-09, Vol.54 (11), p.1091-1098
• Main Authors: de Almeida, Ronei, Moraes Costa, Alyne, de Almeida Oroski, Fábio, Carbonelli Campos, Juacyara
• Format: Article
• Language: English
• Subjects: Air entrainment; Ammonia; Ammonia - analysis; ammonia stripping; Biological Oxygen Demand Analysis; Brazil; Calcium Compounds - chemistry; Chemical oxygen demand; Coagulation; coagulation-flocculation; Combined treatment; Dosage; Entrainment; Filtration; Flocculation; Humic acids; Humic Substances - analysis; Jar tests; Landfill; landfill leachate; Landfills; Leachates; Lime; Models, Theoretical; Nanofiltration; Nanotechnology; Nitrogen; Organic carbon; Organic chemistry; Organic matter; Oxides - chemistry; Pollution effects; Stripping; Surface water; Total organic carbon; Waste disposal sites; Waste treatment; Wastewater treatment; Water Pollutants, Chemical - analysis; Water pollution treatment; Water Purification - methods
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2019.1631093

Landfill leachate consists mostly of a high content of refractory organic matter, ammonia and toxic compounds. All these compounds, regardless of their nature, have a potential pollution effect on local ground and surface waters. In this context, the purpose of the present study was to evaluate a treatment process (coagulation-flocculation with lime coupled with nanofiltration) applied to landfill leachate from Seropédica, Rio de Janeiro (Brazil). Jar tests were conducted to determine the optimum dosage of lime (ranged from 0 to 10 g L −1 ) and, at optimum lime dose, ammonia nitrogen was removed during coagulation-flocculation process due to high pH. The process was settled for 6 h with slow stirring (50 rpm) to promote air entrainment and NH 3 -N stripping before using the final treatment step of nanofiltration at 8 bar. After ammonia stripping, NH 3 -N was reduced from 1,236 mg L −1 to 353 mg L −1 (71% removal efficiency). At the end of the combined treatment, TOC (total organic carbon), HS (humic substances) and COD (chemical oxygen demand) removals were 89%, 80% and 94%, respectively. The results showed that the combined process was effective in the removal of recalcitrant compounds and NH 3 -N.