High-gravity photocatalytic degradation of tetracycline hydrochloride under simulated sunlight

Abstract

Oxygen can generate reactive oxygen species in photocatalysis, promoting organic matter's mineralization. Therefore, enhanced oxygenation of the photocatalytic degradation system will help improve photocatalytic degradation efficiency. This study developed a novel high-gravity photocatalytic degradation method, which leverages the robust gas–liquid mass transfer capability of a supergravity rotating bed to realize the enhanced oxygenation of the photocatalytic degradation system. Specifically, this study used graphitic carbon nitride as the catalyst and tetracycline hydrochloride as the model pollutant. The effects of packing thickness, catalyst concentration, liquid flow rate, rotor speed, gas flow rate, and initial pH value on photocatalytic degradation performance were investigated. The results showed that the degradation rate of tetracycline hydrochloride reached 84.6 % under the optimal conditions of the rotating packed bed, which was 14.8 % higher than that of the traditional photocatalytic degradation process.