Removal of Selected Benzothiazols with Ozone

Abstract

Benzothiazole derivatives are widely used as industrial chemicals in the leather and wood industries, as bio-corrosion inhibitors in cooling systems, ingredients in anti-freezing agents for automobiles, and mainly as vulcanisation accelerators in rubber production. Correspondingly, these xenobiotic compounds are widely distributed in the environment and they have been detected in industrial wastewaters, as well as in soils, estuarine sediments, and superficial waters (Valdes & Zahor, 2006). They cause environmental concern when released into watercourses (Valdes et al., 2008). These compounds inhibit micro-organisms’ activity in conventional biological wastewater treatment systems and most of them are not readily biodegradable (de Wewer & Verachter, 1997; de Wewer, 2007). Moreover, they can be absorbed onto cell membranes, leading to bioaccumulation (Gaja & Knapp, 1998). According to Knapp et al. (1982), 7.0 mg.l-1 BT causes a 50% and 54 mg.l-1 a 100% inhibition of ammonia oxidation, while nitrate utilization is not affected (de Wever and Verachter, 1997). Tomslino et al. (1966) proved 75% inhibition of ammonium nitrogen oxidation at the concentration of 3 mg.l-1 MBT. HOBT causes 100% inhibition of oxidation of ammonium nitrogen at 60 mg.l-1 (Hauck, 1972).