The Journal of

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Introduction: The most important affect of natural organic matters in water is their reaction with chlorine and producing of disinfection byproducts that are carcinogenic. Humic acid is most common natural organic materials of surface water. Advanced oxidation processes (AOPs) are methods for the removal of organics from aqueous solutions. Application of electron beam radiation is one of these methods for water treatment. The aim of this study was to evaluate the efficiency of catalytic oxidation process of electron beam radiation with potassium persulfate in removal of humic acid from aqueous solutions. Methods: This experimental study was performed in laboratory scale. In this study, effect of pH (4 -10), initial concentration of potassium persulfate (0.1- 0.5 mmol/100cc), different radiation doses of electron beam (1-15 kGy) and the initial concentration of Humic acid (10-50 mg/l) in removal of humic acid were studied. Electron irradiation performed using an electron accelerator model TT200. Residual concentrations of humic acid in the samples determined by spectrophotometer UV/Vis at a wavelength of 254 nm. Results: Based on the results, changes in pH had little effect on the Humic acid removal efficiency. The average, with increasing of pH from 4 to 10, the removal efficiency of humic acid from 72.59% to 73.36% increased, respectively. The results showed that increasing of the dose from 1 to 15 kGy, humic acid removal efficiency increases. Based on results by increasing of persulfate concentration, the removal efficiency increased so that with increasing of concentration of potassium persulfate from 0.1 to 0.5 mmol/100cc, removal efficiency from 69.43% to 83.82% was increased. Kinetic experiments showed that the decomposition of humic acid by electron beam radiation followed the second-order kinetic. Conclusion: The data from this study showed that the aqueous solution containing acid Humic is decomposed effectively by electron beams irradiation. Addition of potassium persulfate can be have significant improvements in removal efficiency of humic acid in the presence of electron beam.

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Introduction: Due to the increasing use of irradiation in food safety as an efficient and supplement method, it is needed to investigate effects of this new technology on the apparent and organoleptic characteristics of different products. Because primarily thing that attracts the attention of the customer to buy a food product is its appearance characteristics. The aim of this study was to determine the effect of electron beam irradiation on traditional ice cream.

Methods: Ice cream samples were shopped in the city and were moved to the laboratory in defined conditions into the cool box to keep sample frozen. In keeping with freezing conditions, samples were irradiated by electron beam in -18at doses of 0, 1, 2, 3 and 5 kGy. And after one week of storage at -18℃, physicochemical tests including moisture, fat, sugar, pH and sensory tests including color, odor, taste and overall acceptability, were done on it.

Results: Results showed that there was no significant difference between irradiated and non-irradiated in the amount of sugar, fat and pH. However, it can be seen significant differences in the moisture content measured in the treated samples with electron beam and untreated one (p<0.05) Also, although the doses of 1 and 2 kGy had no significant effect on the organoleptic characteristics of the product, but with increasing irradiation dose up to 2 kGy, overall acceptability  ​​and color significantly decreased (p<0.05).

Conclusion: According to the result,  it can be concluded that the maximum recommended dose is 2 kGy for irradiation traditional ice cream product and  higher doses caused a decline in quality of product.

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Background: Humic acids (HAs) have adverse effects on the environment; therefore, they should be removed from the water and wastewater. The aim of this study was to evaluate the efficiency of the electron beam irradiation for removal of humic acid from aqueous solutions.

Methods: Humic acid was purchased from Sigma-Aldrich Company. After preparation of stock solution in alkaline condition, different concentrations of humic acid (10, 25 and 50 mg) were prepared. Study has done at pH= 8 and in different dose rates of 1, 3, 6, 9 and 15 kGy. Then initial absorption of samples was measured at 254 nm using UV-Visible spectrophotometer before and after the irradiation. Excel and SPSS Ver. 18 were used for analyzing the data and drawing graphs.

Results: The results of this study showed that by increasing adsorbed dose from 1 to 15 kGy, the efficiency of HA removal increased and by increasing humic acid concentration from 10 to 50 mg/L, the removal efficiency of humic acid decreased. The results of the kinetic study showed that irradiation of humic acid followed pseudo second-order reaction.

Conclusion: It can be concluded that electron beam irradiation can be a useful technology for the treatment of environmental samples contaminated by humic acid.