title: Advanced treatment of benzothiazole contaminated waters: comparison of O3, AC, and O3/AC processes.
abstract: Benzothiazole (BT) is a toxic and poorly biodegradable contaminant, usually found in wastewater from rubber related applications. This compound could be effectively eliminated using advanced treatment processes. This paper compares experimental results on detoxification systems based on ozone oxidation, activated carbon adsorption, and simultaneous adsorption-oxidation using ozone in the presence of activated carbon. The effect of pH (2-11), and the presence of radical scavengers (tert-butyl alcohol and sodium carbonate) on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1 L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with activated carbon adsorption increases the overall BT oxidation rate with respect to the ozonation process and activated carbon adsorption. In the presence of free radical scavenger, only a 44% reduction in BT removal rate is observed in the simultaneous treatment, as compared with 72% when ozonation treatment is used, suggesting that BT oxidation reactions mainly take place on the activated carbon surface.
authors.affiliation: Chemical Eng. Dept., University of Concepción, P.O. Box: 160-C, Correo 3, Concepción, Chile. hvaldesm@udec.cl
authors.forename: H
authors.initials: H
authors.lastname: Valdés
authors.forename: C A
authors.initials: CA
authors.lastname: Zaror
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002254:Carbonates / Q000494:pharmacology; D002606:Charcoal / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D013830:Thiadiazoles / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*; D020002:tert-Butyl Alcohol / Q000494:pharmacology
chemical_list: D002254:Carbonates; D016166:Free Radical Scavengers; D013830:Thiadiazoles; D002606:Charcoal; C015700:benzo-1,2,3-thiadiazole; C005686:sodium carbonate; D010126:Ozone; D020002:tert-Butyl Alcohol