Improved landfill leachate quality using ozone, UV solar radiation, hydrogen peroxide, persulfate and adsorption processes. (15th February 2019)

• Record Type: Journal Article
• Authors: Poblete, Rodrigo; Oller, Isabel; Maldonado, Manuel I.; Cortes, Ernesto
• Is Part Of: Journal of environmental management. Volume 232(2019)
• Page Start: 45
• Page End: 51
• Publication Date: 2019-02-15
• Subjects: Landfill leachate -- Solar reactor -- Oxidants -- Toxicity; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2018.11.030
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Advanced oxidation processes based on ozonation, UV solar radiation, hydrogen peroxide, and persulfate were tested for the complete treatment of a specific landfill leachate. As a post-treatment of the advanced oxidation process, an additional adsorption process was carried out using a natural zeolite. Application of the UVsolar /O3 /H2 O2 process required 140 min of irradiation and the consumption of 0.67 g/L H2 O2 to eliminate 56% and 17% of colour and chemical oxygen demand (COD), respectively. When adding persulfate to the system (UVsolar /O3 /H2 O2 /S2 O8 −2 ), colour and COD were reduced by 29% and 77%, respectively, with a 0.2 g/L concentration of S2 O8 −2 requiring 250 min of irradiation time. In an experimental run with landfill leachate, adsorption post-treatment with a natural zeolite resulted in 36%, 99%, and 18% total reductions in COD, ammonium, and chloride, respectively. In another experimental run, adsorption with a zeolite was used as a pre-treatment for the advanced oxidation process (UVsolar /O3 /H2 O2 and UVsolar /O3 /H2 O2 /S2 O8 −2 ). The results were similar to those for adsorption post-treatment, with 30%, 90%, and 20% total reductions in COD, ammonium, and chloride, respectively. Despite improvements, some measured parameters of treated landfill leachate still exceeded Chilean regulations for water quality. Furthermore, Lactuca sativa seeds did not germinate after irrigation with 100% treated landfill leachate or dilutions above 3%. Finally, EC50 values were enhanced during treatment, going from 0.002% for raw landfill leachate to 1.179% after the adsorption process. Highlights: The matrix of pollutants existent in landfill leachate is very complex. The use of solar energy can enhance the performance of some reagents. The use of H2 O2 and S2 O8 −2 significantly reduced colour and COD. The use of zeolite in the adsorption process was very effective at removing ammonium. Concentration of some pollutants exceeded Chilean regulations for irrigation.