Photocatalytic process optimization by numerical simulation based on the removal efficiency of carbamazepine under different operating conditions

Abstract

Carbamazepine as a typical ingredient in pharmaceuticals and personal care products (PPCPs) cannot be removed by conventional wastewater treatment processes due to its biorefractory property. In this paper, the effects of photocatalytic operating conditions of wastewater treatment such as stirring speed, composite material dosage, light intensity, and irradiation time on the degradation of carbamazepine by ATC were studied. Considering the aspects of technology, economy, and environment, the photocatalytic process scheme was optimized for carbamazepine wastewater treatment using ATC. The results were analyzed and simulated by response surface methodology (RSM). The effects of various factors and their interactions on the treatment efficiency were analyzed using a multiple quadratic regression equation, by which the optimal process parameters and the process conditions with optimal response were achieved. Under low material dosage (less than 2 g/L), the pair-wise interactions among irradiation time, light intensity, and stirring speed contributed more to the treatment efficiency than medium (2 g/L to 4 g/L) or high (more than 4 g/L) material dosage. The operation cost under low material dosage was relatively low, which shows that material cost is one of the most important factors in the actual photocatalytic process.