Technical Note Peroxymonosulfate activation by phosphate anion for organics degradation in water Xiaoyi Lou a , Liuxi Wu a , Yaoguang Guo a , Chuncheng Chen b , Zhaohui Wang a,⇑ , Dongxue Xiao a , Changling Fang a , Jianshe Liu a , Jincai Zhao b , Shuyu Lu a a State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China b Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100190, China highlights  A novel and efficient PMS activation reaction by PBS was firstly reported.  Neutral pH favors the decomposition and mineralization of organic pollutants.  PBS cannot activate other peroxygens (hydrogen peroxide and peroxydisulfate). graphical abstract article info Article history: Received 29 August 2014 Accepted 8 September 2014 Handling Editor: Jörg E. Drewes Keywords: Peroxygen activation Radical quenching Degradation Mineralization abstract Activation of peroxygens is a critical method to generate oxidative species, but often consumes additional chemical reagents and/or energy. Here we report a novel and efficient activation reaction for peroxymono- sulfate (PMS) by phosphate anions (PBS). The PBS/PMS coupled system, at neutral pH, is able to decompose efficiently even mineralize a variety of organic pollutants, such as Acid Orange 7, Rhodamine B and 2,4,6-tri- chlorophenol. In contrast, no measurable degradation was observed when the PMS was replaced by other peroxygens (i.e. hydrogen peroxide and peroxydisulfate). Both PMS and PBS are indispensable for the oxi- dative degradation of pollutants. Increasing pH and concentrations of PMS and PBS significantly accelerate the degradation of organics. It is proposed that Å OH would be the major radical for contamination degrada- tion at pH 7.0 through the radical quenching experiments. This work provides a new way of PMS activation for decontamination at neutral pH, in particular for phosphate-rich wastewater treatment. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Sulfate radicals (SO 4 Å ) based advanced oxidation processes (AOPs) have recently attracted increasing attention (Anipsitakis et al., 2008; Ahmad et al., 2013), due to their high efficiency and selectivity towards degradation of refractory organic pollutants. Compared with Å OH (E 0 = 1.8–2.7 V), a major reactive radical in these conventional AOPs, SO 4 Å has a higher redox potential of 2.5–3.1 V (Neta et al., 1988). In practice, SO 4 Å can be generated from the decomposition of peroxygen and photolysis of Fe(III)-sulf- http://dx.doi.org/10.1016/j.chemosphere.2014.09.046 0045-6535/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +86 21 67792557; fax: +86 21 67792522. E-mail address: zhaohuiwang@dhu.edu.cn (Z. Wang). Chemosphere 117 (2014) 582–585 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere