title: Optimal conditions for chlorothalonil and dissolved organic carbon in horizontal subsurface flow constructed wetlands.
abstract: The most efficient system of horizontal subsurface flow constructed wetlands (HSSFCW) for removing dissolved organic carbon (DOC) in the presence of chlorothalonil pesticide (CLT) present in synthetic domestic wastewater was determined using the macrophyte Phragmites australis. Two concentrations of CLT (85 and 385 μg L-1) and one concentration of glucose (20 mg L-1) were evaluated in four pilot scale horizontal surface flow constructed wetlands coupled with two sizes of silica gravel, igneous gravel, fine chalky gravel (3.18-6.35 mm), coarse gravel (12.70-25.40 mm) and two water surface heights (20 and 40 cm). For a month, wetlands were acclimated with domestic wastewater. Some groups of bacteria were also identified in the biofilm attached to the gravel. In each treatment periodic samplings were conducted in the influent and effluent. Chlorothalonil was quantified by gas chromatography (GC-ECD m), DOC by an organic carbon analyzer and bacterial groups using conventional microbiology in accordance with Standard Methods. The largest removals of DOC (85.82%-85.31%) were found when using fine gravel (3.18-6.35 mm) and the lower layer of water (20 cm). The bacterial groups quantified in the biofilm were total heterotrophic, revivable heterotrophic, Pseudomonas and total coliforms. The results of this study indicate that fine grain gravel (3.18-6.35 mm) and both water levels (20 to 40 cm) can be used in the removal of organic matter and for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT in HSSFCW.
authors.affiliation: a Grupode Investigación Microbiologia y Ambiente (GIMA), Facultad de Ciencias de la Salud, Universidad de San Buenaventura , Cartagena , Colombia.|b Grupo Diagnóstico y Control de la Contaminación (GDCON), Facultad de Ingenierías, Universidad de Antioquia , Medellín , Colombia.
authors.forename: Karina A
authors.initials: KA
authors.lastname: Rìos-Montes
authors.affiliation: b Grupo Diagnóstico y Control de la Contaminación (GDCON), Facultad de Ingenierías, Universidad de Antioquia , Medellín , Colombia.|c Grupode Investigación Ciencia e Ingenieria en Sistemas Ambientales (GCISA), Facultad de Ingeniería Civil , Departamento de Ingeniería Ambiental , Universidad del Cauca , Popayán , Colombia.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Casas-Zapata
authors.affiliation: d Laboratorio de Remediación Ambiental, Instituto de Metalurgia-Facultad de Ingeniería. Universidad Autónoma de San Luis Potosí , San Luis Potosí , México.
authors.forename: Roberto
authors.initials: R
authors.lastname: Briones-Gallardo
authors.affiliation: b Grupo Diagnóstico y Control de la Contaminación (GDCON), Facultad de Ingenierías, Universidad de Antioquia , Medellín , Colombia.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Peñuela
mesh_terms: D000641:Ammonia / Q000378:metabolism; D018441:Biofilms; D002244:Carbon / Q000737:chemistry; D002849:Chromatography, Gas; D059013:Microbial Consortia; D009570:Nitriles / Q000032:analysis; D010710:Phosphates / Q000378:metabolism; D006109:Poaceae; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods; D053833:Wetlands
chemical_list: D000641:Ammonia; D002244:Carbon; D009570:Nitriles; D010710:Phosphates; D062065:Wastewater; C005806:tetrachloroisophthalonitrile
keywords: Chlorothalonil; Phragmites australis; biofilm; constructed wetlands; dissolved organic carbon