Simultaneous photocatalytic oxidation of As(III) and humic acid in aqueous TiO2 suspensionsSimultaneous photocatalytic oxidation of As(III) and humic acid in aqueous TiO2 suspensions Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-222009enThe simultaneous photocatalytic oxidation of As(III) and humic acid (HA) in aqueous Degussa P25 TiO(2) suspensions was investigated. Preliminary photocatalytic studies of the binary As(III)/TiO(2) and HA/TiO(2) systems showed that As(III) was oxidized more rapidly than HA and the extent of photocatalytic oxidation of each individual component (i.e. As(III) or HA) increased with decreasing its initial concentration and/or increasing catalyst loading. The simultaneous photocatalytic oxidation of As(III) and HA in the ternary As(III)/HA/TiO(2) system showed that both As(III) and HA oxidation was reduced in the ternary system compared to the corresponding binary systems. The effect of operating conditions in the ternary system, such as initial As(III), HA and TiO(2) concentrations (in the range 3-20mg/L, 10-100mg/L and 50-250 mg/L respectively), initial solution pH (3.6-6.7) and reaction time (10-30 min), on photocatalytic As(III) and HA oxidation was assessed implementing a two-level factorial experimental design methodology. Seven and ten factors were found statistically important in the case of photocatalytic As(III) and HA oxidation respectively. Based on these statistically significant factors, a first order polynomial model describing As(III) and HA photocatalytic oxidation was constructed and a very good agreement was obtained between the experimental values and those predicted by the model, while the observed differences may be readily explained as random noise.http://creativecommons.org/licenses/by/4.0/Journal of Hazardous Materials1691-3376-385 Tsimas Emmanuil S. Tyrovola Konstantina Τυροβολα Κωνσταντινα Xekoukoulotakis Nikos Ξεκουκουλωτακης Νικος Nikolaidis Nikolaos Νικολαιδης Νικολαος Diamantopoulos Evaggelos Διαμαντοπουλος Ευαγγελος Mantzavinos Dionysis Μαντζαβινος Διονυσης Elsevier Factorial design Humic acid Photocatalysis Water