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The degradation kinetics and mechanisms of Rhodamine B (RhB) dye by • OH and SO 4 •- based advanced oxidation processes were investigated. The • OH and SO 4 •- radicals were generated by UV photolysis of hydrogen peroxide and persulfate (i.e., UV/H 2 O 2 and UV/PS), respectively. The effects of initial solution pH, RhB concentration, oxidant dosage, Fe 2+ concentration, and water matrices were examined. The results showed that the degradation of RhB followed pseudo-first-order kinetics in both processes, with the UV/H 2 O 2 process exhibiting better performance than that of the UV/PS process. Acidic conditions were favorable to the degradation of RhB in both systems. Increasing the oxidant dosage or decreasing the contaminant concentration could enhance the degradation of RhB. Photo-Fenton-like processes accelerated the performance when Fe 2+ was added into both systems. The removal efficiency of RhB was inhibited upon the addition of humic substances. The addition of Cl - displayed no significant effect and promoted RhB degradation in UV/H 2 O 2 and UV/PS systems, respectively. The presence of NO 3 - promoted RhB degradation, while H 2 PO 4 - and C 2 O 4 2- showed an inhibitory effect on both UV/H 2 O 2 and UV/PS processes. Radical scavenging tests revealed the dominant role of SO 4 •- radicals in the UV/PS system. Furthermore, the evolution of low molecular weight organic acids and NH 4 + during the degradation of RhB in these two processes were compared. Both UV/H 2 O 2 and UV/PS systems led to similar formation trends of NH 4 + and some ring-opening products (e.g., formic acid, acetic acid, and oxalic acid), suggesting some analogies in the decay pathways of RhB by • OH and SO 4 •- -induced oxidation processes., Competing Interests: Declaration of competing interest The authors declare that they have no known personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

PM 2.5 and PM 10 samples were collected in the semi-arid city of Xi'an in Northwest China from November 2016 to November 2017 and analyzed to assess pollution characteristics, sources, health risks, and influencing factors of 6 priority phthalate esters (PAEs). The results showed that the sum of the 6 PAEs (Σ 6 PAEs) was 85.5 ng m -3 in PM 2.5 and 94.5 ng m -3 in PM 10 , being higher at the suburban site than the urban site and winter > spring > summer > autumn. The most abundant PAE was bis(2-ethylhexyl phthalate) (DEHP). PM 2.5 - and PM 10 -bound PAEs were associated mainly with the use of plasticizers plus the uses of cosmetics and personal care products, construction materials, and home furnishings. Temperature, relative humidity, and visibility had stronger influences on the concentrations of PM and PM-bound PAEs than pressure and wind speed. Pressure and relative humidity were positively correlated with the concentrations of PM and most of the PM-bound PAEs, while temperature, visibility and wind speed had negative correlations with the concentrations of PM and PM-bound PAEs. The non-carcinogenic risks of human inhalation exposure to PM-bound PAEs were in the range of 10 -7 to 10 -3 , suggesting low non-cancer risks, which were higher at the suburban site than the urban site and higher to children than adults. The cancer risks of human inhalation exposure to PM-bound DEHP and butyl benzyl phthalate (BBP) were in the range of 10 -12 to 10 -10 , suggesting low carcinogenic risks, being in the order of the suburban site > the urban site and DEHP > BBP. Special attention should be paid to long-term low dose exposure to PAEs in the suburb, especially in winter and spring., (Copyright © 2019 Elsevier Ltd. All rights reserved.)