Assisted sonocatalytic degradation of pethidine hydrochloride (dolantin) with some inorganic oxidants caused by CdS-coated ZrO2 composite

•CdS-ZrO2 as sonocatalyst was used to degrade dolantin under ultrasonic irradiation.•US/CdS-ZrO2/K2S2O8 system displayed excellent degradation efficiency of dolantin.•Sonocatalytic degradation mechanism of dolantin in CdS-ZrO2/oxidants was proposed.

CdS was synthesized via hydrothermal method and CdS-coated ZrO2 composite was prepared via chemical precipitation method. And then they were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). After that, the sonocatalytic degradation of pethidine hydrochloride (dolantin) in aqueous solution was conducted adopting CdS-coated ZrO2 composite as sonocatalyst with inorganic oxidant assisted. In addition, some influencing factors such as inorganic oxidant kind, including persulfate (K2S2O8), perchlorate (NaClO4) and periodate (KIO4), inorganic oxidant concentration and ultrasonic irradiation time on sonocatalytic degradation of pethidine hydrochloride were examined by using gas chromatograph. The experimental results showed that the used inorganic oxidants can effectively assisted the sonocatalytic degradation of pethidine hydrochloride caused by CdS-coated ZrO2 composite and the increase effects arrange as the order of K2S2O8 > KIO4 > NaClO4. And the best sonocatalytic degradation ratio (95.50%) of pethidine hydrochloride could be obtained when the conditions of 10.00 mmol/L K2S2O8, 1.00 g/L prepared CdS-coated ZrO2 composite, 135 min ultrasonic irradiation (40 kHz frequency and 300 W output power), 100 mL total volume and 25–28 °C temperature were adopted. However, only using CdS-coated ZrO2 as sonocatalyst without any inorganic oxidants merely reaches 20% degradation ratio of pethidine hydrochloride when other conditions are the same. The method of sonocatalytic degradation assisted with inorganic oxidants may be an efficient sonocatalytic system for degradation of pethidine hydrochloride.

Graphical abstractCdS was synthesized via hydrothermal method and CdS-coated ZrO2 composite was synthesized via chemical precipitation method. The sonocatalytic degradation of pethidine hydrochloride (dolantin) in aqueous solution was conducted adopting CdS-coated ZrO2 composite as sonocatalyst with inorganic oxidant assisted. The experimental results showed that some inorganic oxidants can effectively assist the sonocatalytic degradation of pethidine hydrochloride in the presence of CdS-coated ZrO2 composite. The best sonocatalytic degradation ratio (95.50%) of pethidine hydrochloride could be obtained when the conditions of 10.00 mmol/L K2S2O8, 1.00 g/L prepared CdS-coated ZrO2 composite, 135 min ultrasonic irradiation (40 kHz frequency and 300 W output power), 100 mL total volume and 25–28 °C temperature were adopted.Figure optionsDownload full-size imageDownload as PowerPoint slide