Tetracycline is a well-known emerging contaminant which affects water environment. In this study, an electro/peroxydisulfate system catalyzed with Fe 2+ loaded on granular activated carbon (EC/Fe-GAC/PS) was used to treat tetracycline hydrochloride (TCH). Experimental results indicated that the removal efficiency of TCH was 86.12% by the EC/Fe-GAC/PS system. When TCH initial concentration was less than 20 mg/L, the removal efficiency of TCH was similar. The removal efficiency of TCH reached highest value when initial pH was 3, Fe-GAC concentration was 0.5 g/L and plate spacing was 9 cm, respectively. When the concentrations of PS and Na 2 SO 4 reached 3.0 mmol/L and 25 mmol/L, respectively, the removal rate of TCH was the highest. When the current density increased to 20 mA/cm 2 , the degradation efficiency of TCH began to decline. When the plate spacing is 9cm, the residual amount of TCH is the lowest. In a certain range, separately increasing of PS concentration, Na 2 SO 4 concentration, and current density would enhance the degradation efficiency of TCH. The free radical experiments showed that SO 4•played a leading role in acid conditions. According to data analysis, the reaction kinetic model of EC/Fe-GAC/PS system fitted first-order reaction kinetic model. The order of factors affected reaction efficiency was: plate spacing>current density>PS concentration>Fe-GAC concentration>Na 2 SO 4 concentration in the EC/Fe-GAC/PS system. This study showed that the EC/Fe-GAC/PS process was an efficient, environmental friendly and feasible way to degrade the tetracycline antibiotics in water.

The composition of cutting fluid wastewater is complex, containing oil and various additives. Due to different production processes, various metal particles will be mixed, which has caused great difficulties in wastewater treatment. In this study, electro-flocculation-multiphase Fenton/ultrasound system was used to treat cutting fluid organic wastewater. Firstly, the demulsification pretreatment was carried out by electroflocculation method, which achieved 97.4% COD cr removal efficiency. Afterwards, a multiphase Fenton/ultrasonic system was used for advanced treatment. By comparing the SEM results, BET results, XRD results and COD cr removal efficiency of the catalysts prepared by different supports and methods, CuO/CeO 2 catalyst prepared by the deposition precipitation method was used in this experiment. The dissolution rate of copper in the catalyst CuO/CeO 2 was only 1.29% after 4 hours of reaction. After 5 times of recovery, the recovery rate of the catalyst was still 95%, and the removal efficiency of COD cr was 29.8%. It proved that the catalyst CuO/CeO 2 had good stability. Compared with a separate multiphase Fenton or ultrasound system, the multiphase Fenton/ultrasonic system had a better processing effect. Under the conditions of an ultrasonic frequency of 800 KHz, a reaction time of 180 min, a catalyst dosage of 1.6 g/L, a hydrogen peroxide dosage of 0.5 mol/L, and an initial pH of 8, the multiphase Fenton/ultrasonic system could achieve 65% COD cr removal efficiency. This study found that electro-flocculation-multiphase Fenton/ultrasonic system could finally achieve 99.09% COD cr removal efficiency.