Efficiency And Kinetics Of Organic Pollutians Degradation In Simulated Solar Activated Persulfate Systems

Utilizing Persulfate Based Advanced Oxidation（PB-AO）for the treatment of emerging organic pollutants in water has been so far one of the hotspots technologies domestically and internationally.This research simulated visible light to activate two oxidants:peroxymonosulfate（PMS）and persulfate（PS）.The kinetics of micropollutants degradation（Aspirin（ASA）,Flunixin Meglumine（FMME）,Nitrobenzene（NB）and Benzoic Acid（BA））in water,as well as the evaluation of application,were studied in this manuscript.Solar/PS system can efficiently degrade four pollutants in a pseudo-first order kinetic pattern.When[ASA]₀=[FMME]₀=[NB]₀=[BA]₀=10.0μM,PS at 1.0 m M and pH at 7.0,the removal of ASA,FMME,NB and BA within 15 minutes were 72.6%,97.5%,21.8%and 93.1%,respectively.The generation of reactive oxygen species including·OH,SO₄^·-,¹O₂ and O₂^·-in the system was proved according to probe compounds degradation.The contribution of·OH,SO₄^·-and ¹O₂ to pollutants removal was calculated.SO₄^·-and ¹O₂were supposed to dominate pollutant degradation.The economic analysis suggested that the EE/O ranges of Solar/PS system were 23.5～86.5 k Whm^-3order^-1 and the optimal oxidant dosages were calculated（1.02～2.99 m M）.This system still maintained degradation potential for pollutants in actual water matrix,and the removal rate of FMME got as high as 93.0%.At the same time,the Solar/PS system,serving as a pre-oxidation process,can reduce the disinfection by-products（DBPs）formation in and the following chlorination processes.After natural organic matter（NOM）and actual water matrix were disposed,the concentrations of generated trihalomethanes（THMs）and haloacetic acids（HAAs）decreased on average by 18.5%and 41.0%,respectively.The removal of aforementioned pollutants in the Solar/PMS system at[PMS]₀=2.0 m M and pH7.0 within 15 min were 63.1%,61.4%,41.7%and 81.2%,respectively.Results indicated that at·OH and SO₄^·-were discerned in Solar/PMS system.The contribution ratios of SO₄^·-to ASA and FMME degradation were 48.6%and 52.0%,respectively.The mineralization in Solar/PMS system was lower than Solar/PS system.The range of EE/O was 72～110 k Whm^-3order^-1,and the optimal oxidant dosage was 0.36～0.68 m M.Solar/PMS system can also effectively degrade the pollutants in the actual water matrix,45.0%FMME and 51.0%BA were degraded within 15 minutes;when applied as a pre-oxidation process to degrade pollutants and treat actual water samples,the system failed to effectively control the generation of DBPs.After oxidizing pollutants alone,the concentrations of THMs and HAAs increased by 10.1%and 834%on average.On the contrary,the concentration of THMs decreased by 24.7%after oxidizing NOM.