Degradation of sunscreen agent p-aminobenzoic acid using a combination system of UV irradiation, persulphate and iron(II)

作者：Xue, Yicen; Dong, Wenbo^*; Wang, Xiaoning; Bi, Wenlong; Zhai, Pingping; Li, Hongjing^*; Nie, Minghua

来源：Environmental Science and Pollution Research, 2016, 23(5): 4561-4568.

DOI：10.1007/s11356-015-5631-z

• p-Aminobenzoic acid
• Persulphate
• Ferrous ion
• UV irradiation
• Natural anions
• Free radicals

Increased usage and discharge of sunscreens have led to ecological safety crisis, and people are developing the advanced oxidation processes (AOPs) to treat them. The present study aimed to determine the degradation efficiency and mechanism of the sunscreen agent p-aminobenzoic acid (PABA) using the UV/Fe2+/persulphate (PS) method. A series of irradiation experiments were conducted to optimise the system conditions and to study the impacts of the natural anion. Free radicals and degradation products were identified in order to clarify the degradation mechanism. Initial PS and Fe2+ concentrations showed significant impacts on PABA degradation. Natural anions, such as Cl-, NO3-, H2PO4- and HCO3-, impeded PABA degradation because of ion (Fe2+) capture, radical scavenging or pH effects. Hydroxyl (HO center dot) and sulphate (SO4 center dot-) radicals were two main radicals observed in the UV/Fe2+/PS system; of these, SO4 center dot- showed greater effects on PABA degradation. Over 99 % of the available PABA was completely degraded into carbon dioxide (CO2) and water (H2O) by the UV/Fe2+/PS system, and the remaining PABA participated in complex radical reactions. By-products were identified by total ion chromatography and mass spectrometry. Our research provides a treatment process for PABA with high degradation efficiency and environmental safety and introduces a new strategy for sunscreen degradation.

• 出版日期2016-3
• 单位复旦大学