Iranian Journal of

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MicrosoftInternetExplorer4 Background and Objectives: The increasing demand for drinking water has led scientists to the use of saline waters, but existing desalinating processes are very expensive. carbon aerogel is a type of organic aerogel that is suitable for desalination owing to its unique porous structure. Low potential of fouling and deposits, very low wastewater production, electrostatic regeneration of aerogels and, in turn, no need to acid consumption, and lower power consumption are some of this technology benefits.
Materials and Method: In this experimental- analytical study, the purpose was survey of saline and brackish water desalination using carbon aerogel technology and its comparison with electrolysis.The community studied was synthetic salt water samples, using of TDS and EC indicators. The minimum synthetic samples were 243. In this regard, after polymerization of Resorsinol and Formaldehyde compounds under ambient pressure conditions and then its pyrolysis, we fabricated plates of carbon aerogel.
Result: With manufacturing in the pilot-scale, the effect of different parameters, including input salt concentration, current, water flow, distance of between electrodes and pH, on NaCl sorption amount of carbon aerogel electrodes were studied. Generally, adsorption amount increased with increasing of current and NaCl concentration and decreased with increasing of distance electrodes, flow and pH. 
Results: Fabricating reactor at pilot-scale, we studied the effect of different parameters, including input salt concentration, current, water flow, intra-distance of electrodes, and pH on the NaCl sorption using carbon aerogel electrodes. Generally, adsorption capacity increased with increasing of current and NaCl concentration in the inlet flow, and it decreased with increasing intra-distance of electrodes, flow, and pH.
Conclusion: Under the most optimal conditions, our results showed that the NaCl adsorption rate on carbon aerogel electrodes was about 1.43×10^-4 M NaCl per g of carbon aerogels indicating its cost-effectiveness.

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MicrosoftInternetExplorer4 Background and Objectives: The presence of chemical dyes in the water resources not only pollutes them, but also brings about death of organisms and serious indemnities to the environment through stopping oxygen production and preventing penetration of the sunlight. In this study, we investigated the efficiency of the electrolysis process for decolonization of phenolphthalein and phenol red from aqueous environment.
Materials and Methods: The experiments were conducted in an electrochemical reactor having a working volume of 1 liter equipped with 2 graphite electrodes. This study was conducted at laboratory scale. Samples were prepared by dissolving two phenol red and phenolphthalein dyes in drinking water. Then, the effect of operating parameters such as voltage, inter-electrode distance, and NaCl concentration on the complete dye removal was determined considering optimum retention time using  Factorial variance analyses and the graphs were plotted using MS Excel software.
Results: the results showed that the optimum conditions for completely removal of phenolphthalein was achieved applying a voltage of 48 V, the retention time of 9 minutes, 5 cm inter-electrode distance, and the salt concentration of 1.5 g/l, whereas, complete removal of phenol red was achieved applying a voltage of 48 V, the retention time of 8 minutes, 5 cm inter-electrode distance, and the salt concentration of 2 g/l. Under these conditions, COD removal efficiency for phenol red and phenolphthalein was 85 and 80 percent respectively.
Conclusion: This study revealed that electrolysis process is an effective method to remove both phenolphthalein and phenol red dyes from effluent, because it can completely remove the dyes in a short time.

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Background and Objectives: Electro-Fenton process has been widely applied for dye removal from aqueous solution lately. Fenton's reagent is formed in the electrolysis medium through the simultaneous electrochemical reduction of O₂ and Fe³⁺ to H₂O₂ and Fe²⁺ respectively on the cathode surface. In this paper, COD reduction potential and decolorization of real textile wastewater were evaluated by electrochemically generated Fenton reagent process. This wastewater mainly contains non-biodegradable acidic dyes, which are highly resistant against conventional oxidizing agents.
Materials and Methods: Electro-Fenton process was carried out in an open and undivided cell in order to evaluate the removal of color and COD from real textile wastewater using graphite felt (cathode) and Pt plate (anode) at room temperature. The effects of current density, flow rate of air, electrolysis time, initial pH, and ferrous ion concentration were investigated for real textile wastewater.
Results: The results showed that the optimal experimental conditions obtained in electrochemical studies were as follows: current density=4.8 mA cm-2, pH=3, flow rate of air=1.5L/min, Fe²⁺=3mM and reaction time=160 min. Under these conditions, COD removal and decolorization achieved were 63% and 77.2% respectively.
Conclusion: According to the results achieved, electro-Fenton process can be used as a pretreatment for degradation of colored wastewater and refractory pollutants. Moreover, this feasible technology improves biodegradability of the textile wastewater.