title: Atrazine degradation in anaerobic environment by a mixed microbial consortium.
abstract: Atrazine degradation by anaerobic mixed culture microorganism in co-metabolic process and in absence of external carbon and nitrogen source was studied at influent atrazine concentration range of 0.5-15 mg/l. Wastewater of desired characteristic was prepared by the addition of various constituents in distilled water spiked with atrazine. In co-metabolic process, dextrose of various concentrations (150-2000 mg/l) was supplied as external carbon source. The reactors were operated in sequential batch mode in which 20% of treated effluent was replaced by the same amount of fresh wastewater everyday, thus maintaining a hydraulic retention time (HRT) equal to 5 days. In co-metabolic process, 40-50% of influent atrazine degradation was observed. First-order atrazine degradation rate (expressed in day(-1)) was better in co-metabolic process (5.5 x 10(-4)) than in absence of external carbon source (2.5 x 10(-5)) or carbon and nitrogen source (1.67 x 10(-5)). In presence of 2000 mg/l of dextrose, atrazine degradation was between 8% and 15% only. Maximum atrazine degradation was observed from wastewater containing 300 mg/l of dextrose and 5mg/l of atrazine. Influent atrazine concentration did not have much effect on the methanogenic bacteria which was clear from methane gas production and specific methanogenic activity (SMA).
authors.affiliation: Department of Civil Engineering, Vellore Institute of Technology, Vellore, Pin-632 014, India.
authors.forename: Pranab Kumar
authors.initials: PK
authors.lastname: Ghosh
authors.forename: Ligy
authors.initials: L
authors.lastname: Philip
mesh_terms: D001280:Atrazine / Q000032:analysis / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D004783:Environmental Microbiology; D007700:Kinetics; D008697:Methane / Q000378:metabolism; D017672:Nitrogen Compounds / Q000378:metabolism; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods*
chemical_list: D003470:Culture Media; D017672:Nitrogen Compounds; D012722:Sewage; D002244:Carbon; D008697:Methane; D001280:Atrazine