Adsorption is one commonly used technique for treatment of petroleum contaminated water. This study aims to modify the adsorption surface of bentonite clay and activated carbon as organoclay and acid modified activated carbon, respectively. The modified and unmodified adsorbents were characterized by analysis of specific surface area, cation exchange capacity and point of zero charge (pH pzc). Furthermore, adsorbents efficiencies were evaluated in the adsorption of petroleum hydrocarbon from oil-water emulsion. The synthetic wastewater samples were generated by emulsifying diesel oil in distilled water to investigate the effects of: (i) contact time, (ii) initial hydrocarbon concentration, (iii) pH, and (iv) adsorption isotherm. The modification of bentonite and activated carbon produced higher adsorption capacity than the unmodified adsorbents. In addition, the results showed that the adsorption of hydrocarbon depend strongly on pH and increased with increasing contact time and the equilibrium was reached after 3 and 4 hr with clays and activated carbons, respectively. The hydrocarbon removal efficiency achieved in the following order: organic bentonite > acid modified activated carbon > bentonite > activated carbon. The modified bentonite is an excellent alternative in the adsorption of hydrocarbon from oil-water emulsion removal with the highest adsorption capacity (48 mg/g at 2 g/L). Freundlich isotherm was best to describe the adsorption isotherm of hydrocarbons from oil-water emulsion by the all adsorbents.

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Toluene was methylated with methanol and disproportionated using catalysts containing different Pt contents (0.2, 0.4 and 0.6%) supported on H‐ZSM‐5 or H‐mordenite (H‐M) zeolites in a fixed‐bed flow‐reactor operated atmospherically at temperatures of 300–500 °C in a flow of hydrogen. Platinum dispersion in the zeolite supports and acid sites strength distribution were evaluated using hydrogen chemisorption (1:1 stoichiometry) and ammonia temperature programmed desorption (TPD) in a differential scanning calorimeter (DSC). Toluene methylation was much faster on all catalysts than toluene disproportionation (DISP). Both reactions were more accelerated using H‐ZSM‐5 containing catalysts than H‐M containing catalysts. The yield of xylenes, and in particular para‐xylene, was significantly influenced by the yield of trimethylbenzenes (TMBs) in product. The selectivities for para‐, ortho‐ and meta‐xylenes production were found largely dependent on the Pt content in the catalysts, particularly when supported on H‐ZSM5‐zeolite. However, using Pt/H‐M catalysts, these selectivities were not strictly controlled by Pt content in the catalysts.

This study investigated the effectiveness of coating and suspension of Degussa P25 TiO2 photocatalyst to remove natural organic matter (NOM) from surface water for use as power plant feedwater. The catalyst yield, transmittance intensity and X-ray pattern as a function of the number of coatings were characterized. In addition, P25 coating photocatalytic activity was studied. The photocatalytic activity also of P25 suspension with different catalyst concentrations and the reusing of the catalyst without and with regeneration was investigated. Results obtained show that the P25 coatings were transparent with good adhesion to the glass substrate. P25 suspension was found to be more effective in the NOM photodegradation and gave a higher rate constant compared to P25 coating. The maximum rate constants were 0.028 and 0.015 min(-1) at 0.7 g/L P25 suspension and 4 coatings, respectively. After four runs without regeneration and three runs with regeneration of P25 reusing, the photoactivity to remove NOM was still significant.

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