Effects of Combining Ultrasonic Waves and Ultraviolet Radiation on Removing 2-Mercaptobenzothiazole from Aqueous Solution: Experimental Design and Modeling

Nowadays, the pollution of sulfur compounds is gradually increasing due to the growing wastewaters and industrial developments. In this study, 2-mercaptobenzothiazole (MBT) removal from aqueous solution has been investigated using the combination of the ultrasonic and UV waves (ultra/UV). The effective parameters include pH, irradiation time, initial concentration of MBT, and volume of hydrogen peroxide at constant temperature of 25 °C. To exact evaluation of the design of experiments (DOE) and analyze of variance (ANOVA), response surface methodology (RSM) was employed. The results revealed that waves’ energy and subsequently cavitation phenomenon and hydroxyl radicals played significant roles in cracking the studied organosulfur’ bonds. In addition, hydrogen peroxide oxidant promoted the sulfur removal in the process. Maximum sulfur removal was numerically optimized as 99.74 that had an absolute error of 1.47% in comparison with the experimental one (98.29). Finally, COD and DO analyses were studied at optimum conditions. The tests confirmed the experimental results, appropriately. Therefore, the combination of the ultrasonic and UV irradiation can be significantly effective on removing organosulfur’s pollutants in industrial wastewaters and related ones.