Synthesis And Modification Of Zinc Tungstate And Its Application In Pharmaceutical Wastewater Treatment

Zinc tungstate?ZnWO₄?is an important member of tungstate.Previous studies have found that ZnWO₄ has good acoustic catalytic activity and can effectively catalyze the ultrasonic degradation of dye wastewater.However,research on the field of catalytic ultrasonic degradation of pharmaceutical wastewater has not been carried out,ultrasonic technology has a unique advantage in handling toxic and refractory pharmaceutical wastewater.ZnWO₄ is expected to have a good effect in the acoustic degradation of pharmaceutical wastewater.Firstly,the ZnWO₄ semiconductor nanomaterials were synthesized by hydrothermal method.The ZnWO₄ was modified by chemical stirring method to prepare Ag₂O/ZnWO₄ composites,and scanning electron microscopy?SEM?,X-ray diffraction?XRD?and energy dispersive spectrometer?EDS?were used.The product was characterized to demonstrate that the material synthesized was ZnWO₄ and Ag₂O/ZnWO₄ complex.Secondly,the adsorption performance of ZnWO₄ was investigated.Taking the absorbance of methylene blue?MB?solution before and after adsorption as the index,The pH of ZnWO₄ synthetic solution,addition amount of ZnWO₄,initial concentration of MB solution,pH of MB solution,adsorption time and adsorption temperature on the adsorption performance were investigated.Experiments have shown that ZnWO₄ synthesized under the condition of pH=6 has the strongest adsorption capacity and has good recyclability.Thirdly,the acoustic catalytic activity of ZnWO₄ was examined.ZnWO₄catalyzed ultrasonic degradation of Meloxicam?MLX?,the absorbance of MLX solution before and after is an indicator.The pH of ZnWO₄ synthetic solution,addition amount of ZnWO₄,initial concentration of MLX solution,the ultrasonic power,the ultrasonic time were investigated.The effect proves that ZnWO₄ has good acoustic catalytic activity.The generation of ROS in the ultrasonic catalysis process was detected by oxidation-extraction spectrophotometry,The generated ROS mainly include¹O₂ and?OH.Finally,the sonocatalytic activity of Ag₂O/ZnWO₄ complex was investigated.The absorbance of MLX was evaluated by Ag₂O/ZnWO₄ after ultrasonic degradation of MLX solution.The Ag₂O/ZnWO₄ composite ratio,Ag₂O/ZnWO₄ addition amount,the initial concentration of MLX,ultrasonic power,ultrasonic time and other influencing factors are proved.The experimental results show that the sonocatalytic activity of Ag₂O/ZnWO₄ complex is higher than that of pure ZnWO₄.The oxidation-extraction spectrophotometry combined with ROS scavenger proves that the degradation of MLX is related to the production of ROS such as¹O₂ and?OH.In summary,ZnWO₄ has good adsorption capacity and exhibits strong acoustic catalytic activity when degrading pharmaceutical wastewater.The Ag₂O/ZnWO₄composite obtained after modification can significantly enhance the acoustic catalytic activity of ZnWO₄.The above research results provide an experimental basis for ZnWO₄ as an acoustic catalyst for ultrasonic degradation of pharmaceutical wastewater.