title: Mature landfill leachate treatment by coagulation/flocculation combined with Fenton and solar photo-Fenton processes.
abstract: This work reports the treatment of a mature landfill leachate through the application of chemical-based treatment processes in order to achieve the discharge legal limits into natural water courses. Firstly, the effect of coagulation/flocculation with different chemicals was studied, evaluating the role of different initial pH and chemicals concentration. Afterwards, the efficiency of two different advanced oxidation processes for leachate remediation was assessed. Fenton and solar photo-Fenton processes were applied alone and in combination with a coagulation/flocculation pre-treatment. This physicochemical conditioning step, with 2 g L(-1) of FeCl3 · 6H2O at pH 5, allowed removing 63% of COD, 80% of turbidity and 74% of total polyphenols. Combining the coagulation/flocculation pre-treatment with Fenton reagent, it was possible to reach 89% of COD removal in 96 h. Moreover, coagulation/flocculation combined with solar photo-Fenton revealed higher DOC (75%) reductions than single solar photo-Fenton (54%). In the combined treatment (coagulation/flocculation and solar photo-Fenton), it was reached a DOC reduction of 50% after the chemical oxidation, with 110 kJ L(-1) of accumulated UV energy and a H2O2 consumption of 116 mM. Toxicity and biodegradability assays were performed to evaluate possible variations along the oxidation processes. After the combined treatment, the leachate under study presented non-toxicity but biodegradability increased.
authors.affiliation: Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801 Vila Real, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Amor
authors.affiliation: Plataforma Solar de Almería (CIEMAT), Carretera de Senés, Km 4, 04200, Tabernas, Almería, Spain.
authors.forename: Estefanía
authors.initials: E
authors.lastname: De Torres-Socías
authors.affiliation: Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801 Vila Real, Portugal.
authors.forename: José A
authors.initials: JA
authors.lastname: Peres
authors.affiliation: Plataforma Solar de Almería (CIEMAT), Carretera de Senés, Km 4, 04200, Tabernas, Almería, Spain.
authors.forename: Manuel I
authors.initials: MI
authors.lastname: Maldonado
authors.affiliation: Plataforma Solar de Almería (CIEMAT), Carretera de Senés, Km 4, 04200, Tabernas, Almería, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Oller
authors.affiliation: Plataforma Solar de Almería (CIEMAT), Carretera de Senés, Km 4, 04200, Tabernas, Almería, Spain.
authors.forename: Sixto
authors.initials: S
authors.lastname: Malato
authors.affiliation: Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801 Vila Real, Portugal. Electronic address: mlucas@utad.pt.
authors.forename: Marco S
authors.initials: MS
authors.lastname: Lucas
mesh_terms: D057919:Biological Oxygen Demand Analysis; D005427:Flocculation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D011174:Portugal; D014466:Ultraviolet Rays; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D006861:Hydrogen Peroxide; D007501:Iron; D062065:Wastewater; D014874:Water Pollutants, Chemical; C045076:Fenton's reagent
keywords: Biodegradability; Coagulation/flocculation; Fenton reagent; Landfill leachate; Solar photo-Fenton; Toxicity