Tourmaline activated persulfate for degradation of Sirius Turkis GL 01

The high Fe2+ content of tourmaline (TM) has potential of activating a persulfate reaction. However, information pertaining to using TM as an activator in persulfate oxidation process is currently unavailable. In this study, powdered TM was used to activate persulfate (PS) oxidation for decolorization synthetic direct azo dye, Sirius Turkis GL 01 (STGL). Findings revealed that decolorization was significantly enhanced by TM/PS combined with ultrasound. A suitable oxidation condition for removal true color was TM 1.5 g/L, PS 5 x 10(-4) M, US 106 W/cm(2) (20 min sonication at 20 kHz), and initial pH 6.0, which could completely remove the color and COD of 40 mg/L STGL after 20 min treatment. Oxidation condition under higher TM dosage with higher sonication power is beneficial for generation of sulfate radicals, consequently, promoting the oxidation performance of TM/PS process. Results clearly indicated that Fe-tourmaline, can be potentially used to activate PS oxidation for effective decolorization of wastewater containing direct azo dyes.