Degradation of Tinidazole in Water by UV/PSProcess: A Study on Degradation Kinetics,Influencing Factors, and Optimizationfor Most Economical Efficiency

The degradation of refractory organic pollutants such as tinidazole in water holds significant positive implications for the environment.This study employed a combination of ultraviolet (UV) light and persulfate (PS) to remove tinidazole from aqueous solutions.Compared to the individual effects of UV alone (9.4% removal) and PS alone (negligible degradation), the UV/PS process demonstrated a remarkable ability to degrade tinidazole.The degradation process was found to follow pseudo-firstorder kinetics, with a rate constant of 4.8210 -3 s -1 .Quenching experiments revealed that sulfate radicals played a dominant role in the degradation process.Within a certain range, increasing the concentration of the oxidant and the UV power was observed to enhance the degradation efficiency, while pH was found to have a negligible impact on the degradation.Among common ions in water, low chloride ion concentrations were found to slightly promote degradation, whereas high concentrations inhibited it.In contrast, bicarbonate, sulfate, and nitrate ions had minimal effects on the degradation process.Within a defined range, the degradation process was described by a quadratic polynomial model, with degradation efficiency as the dependent variable and dosages of PS, UV power, and reaction time as independent variables.By integrating the quadratic polynomial model into a Python program, the most economically optimal operational parameters for the UV/PS process were calculated as dosages of PS of 0.4202 mM, UV power of 9.9311 W, and reaction time of 7.0526 min, at which Pol. J. Environ.Stud.Vol.XX, No. X (XXXX), 1-12 the total operating cost reached the minimum (1.3970 CNY/m 3 /order).The reliability of these parameters was subsequently validated through experimental verification.