title: Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.
abstract: This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT.
authors.affiliation: Grupo de investigación Ciencia e Ingeniería en Sistemas Ambientales (GCISA), Facultad de Ingeniería Civil, Departamento de Ingeniería Ambiental y Sanitaria, Universidad del Cauca, Popayán, Colombia. juanquis0105@gmail.com
authors.forename: Juan C
authors.initials: JC
authors.lastname: Casas-Zapata
authors.forename: Karina
authors.initials: K
authors.lastname: Ríos
authors.forename: Tomás R
authors.initials: TR
authors.lastname: Florville-Alejandre
authors.forename: Jordi
authors.initials: J
authors.lastname: Morató
authors.forename: Gustavo
authors.initials: G
authors.lastname: Peñuela
mesh_terms: D018407:Bacterial Physiological Phenomena; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000187:drug effects*; D057919:Biological Oxygen Demand Analysis; D002244:Carbon / Q000378:metabolism*; D002849:Chromatography, Gas; D004784:Environmental Monitoring; D005659:Fungicides, Industrial / Q000378:metabolism*; D009570:Nitriles / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism; D010865:Pilot Projects; D006109:Poaceae / Q000254:growth & development; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands
chemical_list: D005659:Fungicides, Industrial; D009570:Nitriles; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D002244:Carbon; C005806:tetrachloroisophthalonitrile