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

Ronei De AlmeidaAlyne Moraes CostaFabio de Almeida OroskiJuacyara Carbonelli Campos
Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering (2019)
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 NH3-N stripping before using the final treatment step of nanofiltration at 8 bar. After ammonia stripping, NH3-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 NH3-N.
Keyphrases
  • room temperature
  • municipal solid waste
  • risk assessment
  • anaerobic digestion
  • air pollution