Biodegradability improvement and toxicity reduction of soil washing effluents polluted with atrazine by means of electrochemical pre-treatment: Influence of the anode material

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:255

Article

Carboneras Contreras, Maria Belen¹  Villasenor Camacho, Jose¹  Jesus Fernandez-Morales, Francisco¹  Canizares Canizares, Pablo²  Rodrigo Rodrigo, Manuel Andres² 

[1] Univ Castilla La Mancha, Chem Engn Dept, Res Inst Chem & Environm Technol ITQUIMA, E-13071 Ciudad Real, Spain

[2] Univ Castilla La Mancha, Chem Engn Dept, Fac Chem Sci & Technol, E-13071 Ciudad Real, Spain

关键词: Atrazine;    Soil washing effluent;    Anodic oxidation;    Biodegradability;    Toxicity;   

DOI  :  10.1016/j.jenvman.2019.109895

来源: Elsevier

【 摘 要 】

This work focuses on the partial anodic electro-oxidation of atrazine-polluted soil washing effluents (SWE) in order to reduce its toxicity and to improve its biodegradability. Concretely it has been evaluated the influence of the anodic material used. It is hypothesized that such partial oxidation step could be considered as a pretreatment for a subsequent biological treatment. At first, atrazine was extracted from a polluted soil by means of a surfactant-aided soil-washing process. Then, four different anodic materials were studied in partial electrooxidation pre-treatment batch experiments at different electric charges applied: Boron Doped Diamond (BDD), Carbon Felt (CF), and Mixed Metal Oxides Anodes with Iridium and Ruthenium. Atrazine, TOC, surfactant and sulphate species concentrations, as well as changes in toxicity and biodegradability, were monitored during electrochemical experiments, showing important differences in their evolution during the treatment. It was observed that BDD was the most powerful anodic material to completely degrade atrazine. The other materials achieve an atrazine degradation rate about 75%. Regarding mineralization of the organics in SWE, BDD overtakes clearly the rest of anodes tested. CF obtains good atrazine removal but low mineralization results. All the anodes tested slightly reduced the ecotoxicity of the water effluents. About the biodegradability, only the effluent obtained after the pre-treatment with BDD presented a high biodegradability. In this sense, it must be highlighted the mineralization obtained during the BDD pre-treatment was very strong. These results globally indicate that it is necessary to find a compromise between reaching efficient atrazine removal and biodegradability improvement, while also simultaneously avoiding strong mineralization. Additional efforts should be made to find the most adequate working conditions.

【 授权许可】

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