Peroxymonosulfate/solar radiation process for the removal of aqueous microcontaminants. Kinetic modeling, influence of variables and matrix constituents

New technologies to address the presence of pharmaceutical and personal care products (PPCPs) in wastewater are needed, especially in those cases in which water will be reused. In this work, the activation of peroxymonosulfate (PMS) with simulated solar radiation has been applied to the oxidation of a mixture of six PPCPs, i.e. caffeine, primidone, N,N-diethyl-3-methylbenzamide (DEET), methylparaben, clofibric acid and ibuprofen. The sole application of solar radiation, i.e. solar photolysis, only led to the oxidation of clofibric acid (complete degradation in 90 min). The combination of PMS and solar radiation resulted in the degradation of all target micropollutants. The complete degradation of this mixture at initial 100 ppb was achieved with 0.5 mM of initial PMS after 90 min. A kinetic study that acceptably simulates the experimental data under different conditions has been proposed. The effects of initial PPCP concentration (1 mg L-1-100 mu g L-1), PMS dose (0.1 - 5 mM), and pH (3-9) were tested and kinetically simulated. Finally, the PPCPs removal study was carried out in two real water matrices (river and a secondary effluent of an urban wastewater treatment plant). A higher dose of PMS, ten times higher, was required to achieve complete degradation of the micropollutants if compared to ultrapure water.