جستجوی مقالات مرتبط با کلیدواژه « advanced oxidation » در نشریات گروه « مواد و متالورژی »

In recent decades, Iran has been facing severe water deficiency. In all countries, industrial plants are the most water-consuming sectors; thus, industrial wastewater treatment is always a essential subject. Nitro-Toluene derivatives are extensively used in industries, especially the military industry, which itself has an abundant share in industrial wastewater contamination. These compounds are extremely dangerous for living beings and can have irreparable effects, so eradication of them in industrial wastewater is necessary. Photocatalytic processes are one of the particular approaches in industrial wastewater treatment from the advanced oxidation processes subdivision. One of the prominent and most widely used photocatalysts in this process is Titanium Dioxide (TiO2) . This research aims at the investigations for the modification of  TiO2/Bentonite (TB) catalysts for attaining more economical saving and degradation stabilization conditions. To achieve this goal, the Bentonite and TiO2 photocatalyst was synthesized by a co-precipitation procedure, and its catalytic activity on Para Nitro-Toluene (PNT) degradation was examined. The designed TB photocatalyst is made of 5, 10 and 20 % of TB. A suspension reactor and the spectrophotometry was applied for specifying the extent of the degradation. Characterization of modified catalyst was conducted by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray (EDX). The results highlight that with increasing TiO2 percent, degradation rate augmented, and the highest degradation was attained for TB 20% at 59%. However, Under the same conditions, for pure TiO2, the degradation rate is 64%, but with more TiO2 consumption and time. Finally, in order to further confirm the extent of the degradation, chemical oxygen demand (COD) test was performed on the TA20 sample. The results showed that about 53% of PNT has been converted to minerals.

This study is focused on removing toxic aniline from aqueous solutions using advanced oxidation process by UV/ peroxy disulfate. In this study, the effect of various parameters including pH (3-9), the level of radiation (ultraviolet 30 watt lamp, number 2-5), peroxy disulfate dose (0.02 – 0.08 mol/l) and the initial concentration (20 – 100 mg/l) at different contact times (10 – 60 min) on the efficiency of aniline removal in a laboratory reactor with UV lamps and in a batch mode, was studied. The results of this study showed that the efficiency of removing aniline decreased by increasing and decreasing pH from 5 (maximum efficiency = 66.6%, at pH= 5) and also by increasing the concentration of pollutant. But by increasing the amount of radiation and peroxy disulfate dosage (0.02 to 0.08 mol/l, the process efficiencies will be 46 to 82.8% after 60 min, respectively), the efficiency increased. The efficiency of removing aniline in the combined process of UV/peroxy disulfate increased significantly by using peroxy disulfate and UV, individually (96%). In the process, the efficiency of removing aniline from aqueous solution was due to the production of UV effect on Peroxy disulfate and the production of strong oxidizing radicals. Therefore, due to the high performance and low cost raw materials, this process can be used for removing resistant compounds from industrial sewages.

The aim of this research was to remove COD and color from a hazardous municipal landfill leachate using electro-Fenton process. The effects of four important parameters including H2O /Fe2+ molar ratio, current density, pH and reaction time on the process were carefully considered. The response surface methodology (RSM) was applied to minimize the number of runs and investigate the optimum operating conditions. Thirty runs were carried out and the optimum conditions for COD and color removal were statistically obtained as 95.80 and 96.36% at H2O2/Fe2+ molar ratio 0.23, current density 79.20 mA, pH 4.61 and reaction time 14.72 min.