%0 Journal Article %T Discoloration ofAqueous Direct Blue 71 Solutions using UV/H2O2/Nano-SiO2 Process %J International Journal of Environmental Research %I University of Tehran/Springer %Z 1735-6865 %D 2015 %\ 04/01/2015 %V 9 %N 2 %P 721-734 %! Discoloration ofAqueous Direct Blue 71 Solutions using UV/H2O2/Nano-SiO2 Process %K Discoloration %K Surface Response %K Photocatalysis %K SiO2 Nanoparticle %K Direct Blue %R 10.22059/ijer.2015.946 %X The photolytic capability of SiO2 nanoparticles (SiO2-NP) for the discoloration of Direct Blue 71as an environmentally pollutant dye via UV irradiation in the presence of H2O2was assessed and optimized usingresponse surface methodology (RSM) with a D-optimal design. The response of DB71 degradation was found tobe sensitive to the independent factors of reaction time, SiO2-NP and H2O2 concentrations. The discolorationprocess was not pH-dependent and the pHwas not a significant factor in DB71 discolorationmodel. The approachprovided statistically significant quadratic models, which were adequate to predict responses and to carry outoptimization under the conditions studied. The maximum value of discoloration under the optimum operatingconditions was determined to be 99.03% with a time of16 min of irradiation and concentrations of 220 and 155mg/L for H2O2 and SiO2-NP respectively. The results showed that the discoloration increased about 11%byincreasing SiO2-NP concentration from10 to 155 mg/L. The possiblemechanism of SiO2-NP catalytic performancewas assessed. The kinetic study was also examined and indicated that the degradation of DB71 dye obeysLangmuir-Hinshelwoodmodel. %U https://ijer.ut.ac.ir/article_946_85a3ee4b74fa9ece2c05f7f3e6043f2b.pdf