Piezo-promoted persulfate activation by SrBi2B2O7 for efficient sulfadiazine degradation from water

Combining piezoelectric effect and persulfate (PS) activation is a newly developed strategy for refractory emerging contaminants removal. In this work, borate SrBi 2 B 2 O 7 (SBBO) is firstly developed as a piezoelectric material to piezo-assisted activation of PS for the removal of sulfadiazine (SDZ) under ultrasonic irradiation (US). SDZ could be efficiently degraded by 85.61 % in the system of PS/SBBO/US with a pseudo-first-order rate constant of 0.0520 min −1 , which is faster than that in the systems of PS/SBBO (0.0210 min −1 ), SBBO/US (0.0041 min −1 ), PS/US (0.0074 min −1 ), and PS/BaTiO 3 /US (0.0120 min −1 ). The excellent degradation performance of the PS/SBBO/US system is mainly attributed to the piezoelectric effect of the SBBO which plays an important role in PS activation and accelerating reaction. Two oxidation processes , radical process (•O 2 - and •SO 4 - ) and non-radical process ( 1 O 2 and electron transfer), exist during the SDZ degradation. The system of PS/SBBO/US also attains excellent removal efficiency in different SDZ contained water bodies. The possible degradation pathways mainly include cleavage of bonds, ring-opening, and hydroxylation process, and the toxicity of intermediates was predicted by T.E.S.T. software. This study provides new insight into piezoelectric catalysis associated with PS activation for SDZ removal.