New hybrid process of peroxymonosulfate activation on the BiPO₄ to photocatalytic degradation of diclofenac sodium in aqueous solution

ABSTRACT

In this study, BiPO₄ was prepared by precipitation method, which exhibited high peroxymonosulfate (PMS) activation performance for DS degradation under UV irradiation. The PMS/BiPO₄/UV system achieved the superior removal and mineralisation performance for DS (99%). The pH was an important factor, so that at pH 7 and 9 the degradation performance were 99.22% and 98.98%. The removal efficiency increased from 60.64 to 99.12% with increasing doses of BiPO₄ 0.01 to 0.04 g, while with the increase in the dose up to 0.05 g the removal efficiency decreased to 98.86%. The best values for PMS were 0.05 and 0.06 mgL⁻¹, where the removal efficiency of DS were 98 and 99%, while in 0.04 and 0.07 mgL⁻¹ those were lower than 0.05 and 0.06 mgL⁻¹. Simultaneous existence of PMS and BiPO₄ under UV light could improve removal of DS. During reaction, $S{O}_4^{{ }^{\circ }-}$played a major role, and $HO°$ played a secondary role in the present photo-catalytic degradation process. Correspondingly, a possible pathway of DS degradation were proposed. After five times uses of the BiPO₄ the removal efficiency of DS reduced from 99.2% to 97% that was indicating stability and sustainability of PMS/BiPO₄/UV process. In general, PMS/BiPO₄/UV process could be presented as an applicable method with high performance on removal of DS.

KEYWORDS:

• Diclofenac
• SO_4^°
• BiPO₄
• UV light

Acknowledgement

This article is taken from the Master’s thesis of Environmental Health Engineering, Guilan University of Medical Sciences with grant number 99060308 and ethics code IR.GUMS.REC.1399.432. The authors thank and appreciate deputy of research and technology of university for their financial support and the expert of the water and sewage laboratory of the faculty of health who helped in the implementation of this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The work was supported by the This article is taken from the Master’s thesis of Environmental Health Engineering, Guilan University of Medical Sciences with grant number 99060308 and ethics code IR.GUMS.REC.1399.432. [99060308].