Iranian Journal of

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MicrosoftInternetExplorer4 Background and Objectives: Irrigation of agricultural crops using wastewater will increase, in some cases, their growth by 40 to 60 percent. However, this has a high risks for human health because of the presence of higher number of pathogenic organisms. The main purpose of this study was to investigate the feasibility use of Fenton and modified Fenton with copper for the disinfection of raw wastewater.
Materials and Methods: After primarily laboratory physicochemical and biological analysis, the disinfection process was performed in three different phases in each process. First, the disinfectants were injected separately, then we performed disinfection using Fe++ and cu++ ions combined with hydrogen peroxide in order to determine synergistic effect of each catalyst. Direct method was used for fecal coliforms counting. 
Results: Hydrogen peroxide maximum efficiency for inactivation of fecal coliforms was only 0.66log inactivation. Fenton and modified Fenton with copper ions showed a remarkable effect on the bacterial inactivation so that Fenton and modified Fenton with 1 and 2 mg/l of Cu++ inactivated coliforms by 4.73, 3.28, and 4.88 log respectively.
Conclusion: Application of HP alone for the disinfection of raw wastewater is not practicable due to low observed efficiency. However, its combination with ions such as Fe++ and Cu++ increases HP performance in disinfection and has a notable synergistic effect on HP  disinfection power, where, in the presence of each catalyst, hydrogen peroxide can reduce the fecal coliforms of raw wastewater to meet the Iranian Environmental Protection Agency Standards.

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Backgrounds and Objectives: Nowadays, global concerns about nitrate in groundwater and its adverse impact on health have increased. This study aims to evaluate the efficiency of nitrate reduction from aqueous solution through modified Fenton process using Nano scale zero-valent iron. Material and Methods: This research was an experimental study and performed at laboratory scale. Nitrate reduction was conducted by advanced oxidation process of Fe°/FeІІ/FeШ/H₂O₂ at pH 2-10, contact time 10-90 min, nitrate concentrations of 50-300 mg/L, and the molar ratio of [H₂O₂]/[Fe] 0.5-5. The effect of adding H2O2, molar ratio of reagents, contact time, and pH on nitrate removal was examined and optimal conditions for each of these parameters were determined. Spectrophotometer Dr/5000 was used to measure nitrate in the effluent. Results: We found that the optimal parameters in our studywere pH 3, the molar ratio [H₂O₂]/[Fe°] of 0.5, and the contact time 15 min. By applying these conditions, nitrate removal efficiency at the retention time 15 min, initial nitrate concentration of 100 mg/L, iron concentration of 10 mg/L, and pH 4 for FeШ، FeІІ، Fe°، FeІІ/Fe°/H₂O₂ and FeШ/Fe°/H₂O₂ was 10.5, 27.6, 36.5, 62.3, and 74% respectively. Conclusion: According to the experimental results, it was determined that modified Fenton process using zero iron nano-particles can reduce nitrate under optimal conditions and this method can be used for the removal of similar compounds.