Kinetics degradation of phenacetin by solar activated persulfate system

Kinetic degradation of phenacetin (PNT) by solar activated persulfate (PS) system was evaluated in study. The decomposition of PNT well fitted with a pseudo-first order kinetic pattern, and the exceptional removal performance towards PNT (100%) was obtained in the presence of solar irradiation (1.14 × 10 -4 E· m −2 · s −1 ) and 0.3 mM PS at pH 7.0 in 10 min. The consume ratios of persulfate were calculated to be 2.3~16.7%. The steady-state concentrations of hydroxyl radicals ([HO*] ss ) and sulfate radicals ([SO 4 - ·] ss ) were calculated to be (2.41~2.59) × 10 -13 M and (3.75~4.06) × 10 -12 M by probes of nitrobenzene (NB) and benzoic acid (BA), respectively. The contribution of HO* and SO 4 - · accounts for 27.4% and 11.0% in degradation of PNT. The formation of typical trihalomethanes (THMs) after pre-oxidation of solar/PS was evaluated. The concentration of total THMs decreased from 16 μg·L -1 to 15.4 μg·L -1 through pre-oxidation, with cytotoxicity decreased from 1.38 × 10 -5 to 1.27 × 10 -5 . The calculated electrical energy per order (EE/O) in solar/PS were in range of 0.069~0.106 kWh/m/order.