This study investigated the reaction kinetics and degradation mechanism of parabens (methylparaben, ethylparaben, propylparaben and butylparaben) during ozonation. Experiments were performed at pH 2, 6 and 12 to determine the rate constants for the reaction of protonated, undissociated and dissociated paraben with ozone. The rate constants for the reaction of ozone with dissociated parabens (3....

Second-order rate constants of the direct ozone reactions [formula: see text] and the indirect OH radical reactions [formula: see text] for nine chemicals on the US EPA's Drinking Water Contaminant Candidate List (CCL) were studied during the ozonation and ozone/hydrogen peroxide advanced oxidation process (O(3)/H(2)O(2) AOP) using batch reactors. Except for the thiocarbamate herbicides (molina...

The effects of ozonation on the formation potential of typical disinfection byproducts (DBPs) and the changes of genotoxicity during post chlorination of tertiary effluent from a sewage treatment plant were investigated. Ozonation enhanced the yields of all detected chlorine DBPs except CHCl3. At a chlorine dose of 5 mg/L, the three brominated THMs and five HAAs increased, while chloroform decr...

In this study, a new strategy in catalytic ozonation removal method for degradation of phenol from industrial wastewater was investigated. Magnetic carbon nano composite as a novel catalyst was synthesized, characterized and then used in the catalytic ozonation process (COP) and compared with the single ozonation process (SOP). The influential parameters were all investigated. The results showe...

The removal of disinfection byproducts and their precursors was investigated using a combined ozonation-ultrafiltration system. A commercial membrane was coated 20 or 40 times with iron oxide nanoparticles (4-6 nm in diameter). With this membrane, the concentration of dissolved organic carbon was reduced by >85% and the concentrations of simulated distribution system total trihalomethanes and s...

The simultaneous application of ultrasonic irradiation with ozonation was demonstrated to be effective for the oxidation of oxalic acid (H2C2O4/HC2O4/C2O4), a particularly recalcitrant pollutant, to CO2 and H2O. Degradation rates obtained using sonolytic ozonation were found to be more than 16-times faster than predicted by the linear addition of the independent systems. Model calculations and ...

Four pharmaceuticals (ranitidine, nizatidine, doxylamine, and carbinoxamine) were selected as model compounds to assess the efficiency of four oxidants (ozone (O3), chlorine (Cl2), chlorine dioxide (ClO2) and potassium permanganate (KMnO4)) on the removal of amine-based pharmaceutical and personal care products (PPCPs), as well as the reduction of their N-Nitrosodimethylamine formation potentia...

ABSTRACT: In this project, a nano catalyst (TiO2) and ozone combined with each other and they were used for the removal of 4-nitrophenol (4NP) in industerial wastewater. The effect of some operational parameters such as initial pH (3-9), the concentration of pollutant (20-80 mg/L), and amount of TiO2 were investigated. In O3/TiO2 process, the anion radical  formed before the production of hydro...

background : the aim of this study was to evaluate the performance of water ozonation on disinfection by-product formation. methods : experiments were carried out on samples taken from tajan river, mazandaran province, iran. samples of the pre-filtered raw water and from the 3.5-l water tank reservoir (wt) were analyzed for uv-254 absorbance, dissolved organic carbon (doc), hs and non-hs, chlor...