Sara Kahvaei; Afshin Takdastan; Reza Jalilzadeh Yengejeh
Abstract
Background: Nowadays, the discharge of effluents containing chemicals through manufacturers or consumer industries causes major environmental problems. In this study, we assessed the effect of sludge reversal of the clarifier unit on enhancing the coagulant performance of Poly-Aluminum chloride in the ...
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Background: Nowadays, the discharge of effluents containing chemicals through manufacturers or consumer industries causes major environmental problems. In this study, we assessed the effect of sludge reversal of the clarifier unit on enhancing the coagulant performance of Poly-Aluminum chloride in the removal of turbidity/COD/PVC from PVC effluent of Bandar Imam Khomeini petrochemical plant and reduction of the amount of coagulant and costs. Methods: The experiments were carried out by Jar test with poly aluminum chloride (PAC); the returned sludge, as the assisting coagulant, and the amplitude of the differentiates including (5.5-11) pH of coagulant concentration (10-140mg/L) and concentration of returned sludge (2-20 ml) were investigated. To ensure the accuracy and precision, we repeated each stage of the experiment three times. Results: The results showed that the most optimal conditions for coagulant were at pH=8 and the optimum dose of poly aluminum chloride was 25 mg/L plus 5ml of the clear sludge volume in the clarifier. The removal efficiency of turbidity, COD, and PVC under optimum conditions of Poly-Aluminum chloride were reported 99.71%, 97.19%, and 99.55%, respectively. Conclusion: The results indicated that the sludge of the clarifier, as the main assisting coagulant, in addition to increasing the efficiency of the removal turbidity of COD and PVC reduced the dose of the main coagulant.
Mahmood Derakhshan; Mojtaba Fazeli
Volume 5, Issue 4 , October 2017, , Pages 144-152
Abstract
Background:Petrochemical wastewaters are a critical environmental challenge in industrial zones due to the amount of pollutants they release into the environment. Therefore, finding a solution for treatment of the wastewater has become the priority of the researchers. The main objective of this research ...
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Background:Petrochemical wastewaters are a critical environmental challenge in industrial zones due to the amount of pollutants they release into the environment. Therefore, finding a solution for treatment of the wastewater has become the priority of the researchers. The main objective of this research is improvement of petrochemical wastewaters’ biodegradability using Fenton oxidation process and defining the effective parameters on the efficiency of this technique.Methods: In this research, the capability of Fenton method for promoting the biodegradability of hardly-decomposable wastewaters of petrochemical complexes was studied. The actual wastewater of Karoon and Maroon petrochemical complexes were used in this research. Design of the experiments and also the analysis of the experimental results were carried-out using Response Surface Methodology (RSM) with four variables and four parameters. A rector with sizes of 60, 20 and 20 cm was designed and built. The ranges of CODin, H2O2 concentration, Fe2+ dosage, and TDS variation were 1000-2500 mg/L, 1000-4000 mg/L, 500-3000 mg/L, and 4500-11500 mg/L, respectively, and the average ratio of BOD/COD in the inlet stream was 0.09.Results:The range of BOD/COD in the outlet stream was 0.19-0.37 which decreased with the COD growth. The trend of biodegradability promotion with increase in H2O2 concentration and Fe2+ dosage was ascending, while the effect of TDS on biodegradability was not noticeable.Conclusion:The optimum conditions for achieving maximum efficiency of the reactor were COD=1375 mg/L, [H2O2] = 2509.27 mg/L, [Fe2+] = 1753.49 mg/L and TDS = 8622.9 mg/L and the BOD/COD ratio was 0.32.
Mansooreh Dehghani; Mahshid Ghadami; Talat Gholami; Marzieh Ansari Shiri; Zahra Elhameyan; Mohammad Reza Javaheri; narges shamsedini; Samaneh Shahsavani
Volume 3, Issue 4 , October 2015, , Pages 139-145
Abstract
Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Reactive dyes are widely used in textile industry. Advanced oxidation processes are one of the cost-effective methods ...
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Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Reactive dyes are widely used in textile industry. Advanced oxidation processes are one of the cost-effective methods for the removal of these dyes. The main aims of this study were determining the feasibility of using Fenton process in removing Reactive Red 198 (RR-198) dye from aqueous solution and determining the optimal conditions. Methods: This is a cross-sectional study conducted at a laboratory scale. A total of 69 samples were considered and the effect of pH, Fe (II) concentration, H2O2 concentration, initial dye concentration and reaction time were investigated. Results: According to the results, a maximum removal efficiency of 92% was obtained at pH of 3 and the reaction time of 90 min; also, the concentration of Fe (II), H2O2, initial dye concentration were 100 mg/L, 50 mg/L, and 100 mg/L, respectively. The results revealed that by increasing the concentration of Fe (II), H2O2 and initial dye, the removal efficiency was increased. Conclusions: The results showed that Fenton process could be used as a cost-effective method for removing RR-198 dye from textile wastewater efficiently.