title: Coupling Fenton and biological oxidation for the removal of nitrochlorinated herbicides from water.
abstract: The combination of Fenton and biological oxidation for the removal of the nitrochlorinated herbicides alachlor, atrazine and diuron in aqueous solution has been studied. The H2O2 dose was varied from 20 to 100% of the stoichiometric amount related to the initial chemical oxygen demand (COD). The effluents from Fenton oxidation were analyzed for ecotoxicity, biodegradability, total organic carbon (TOC), COD and intermediate byproducts. The chemical step resulted in a significant improvement of the biodegradability in spite of its negligible or even slightly negative effect on the ecotoxicity. Working at 60% of the stoichiometric H2O2 dose allowed obtaining highly biodegradable effluents in the cases of alachlor and atrazine. That dose was even lower (40% of the stoichiometric) for diuron. The subsequent biological treatment was carried out in a sequencing batch reactor (SBR) and the combined Fenton-biological treatment allowed up to around 80% of COD reduction.
authors: Universidad Autónoma de Madrid, Sección Departamental de Ingeniería Química, Carretera Madrid-Colmenar Viejo Km 12.700, 28049 Madrid, Spain. Electronic address: sonia.sanchis@uam.es.
authors: S
authors: S
authors: Sanchis
authors: Universidad Autónoma de Madrid, Sección Departamental de Ingeniería Química, Carretera Madrid-Colmenar Viejo Km 12.700, 28049 Madrid, Spain.
authors: A M
authors: AM
authors: Polo
authors: Universidad Autónoma de Madrid, Sección Departamental de Ingeniería Química, Carretera Madrid-Colmenar Viejo Km 12.700, 28049 Madrid, Spain.
authors: M
authors: M
authors: Tobajas
authors: Universidad Autónoma de Madrid, Sección Departamental de Ingeniería Química, Carretera Madrid-Colmenar Viejo Km 12.700, 28049 Madrid, Spain.
authors: J J
authors: JJ
authors: Rodriguez
authors: Universidad Autónoma de Madrid, Sección Departamental de Ingeniería Química, Carretera Madrid-Colmenar Viejo Km 12.700, 28049 Madrid, Spain.
authors: A F
authors: AF
authors: Mohedano
mesh_terms: D000081:Acetamides / Q000302:isolation & purification / Q000633:toxicity; D001280:Atrazine / Q000302:isolation & purification / Q000633:toxicity; D001673:Biodegradation, Environmental / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D002244:Carbon / Q000032:analysis; D004237:Diuron / Q000302:isolation & purification / Q000633:toxicity; D054750:Ecotoxicology; D006540:Herbicides / Q000302:isolation & purification*; D006843:Hydrocarbons, Chlorinated / Q000302:isolation & purification*; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D013997:Time Factors; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D000081:Acetamides; C045076:Fenton's reagent; D006540:Herbicides; D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical; C000188:alachlor; D002244:Carbon; D004237:Diuron; D006861:Hydrogen Peroxide; D007501:Iron; D001280:Atrazine
keywords: Biodegradability; Ecotoxicity; Fenton oxidation; Herbicides; Sequencing batch reactor