Piezo-promoted persulfate activation by SrBiBO 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 SrBiBO (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, which is faster than that in the systems of PS/SBBO (0.0210 min), SBBO/US (0.0041 min), PS/US (0.0074 min), and PS/BaTiO/US (0.0120 min). 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 and •SO) and non-radical process (O 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.