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.
Abooalfazl Azhdarpoor; Rabieh Hoseini; Mansoureh Dehghani
Volume 3, Issue 4 , October 2015, , Pages 153-159
Abstract
Background: High amount of heavy metals in sludge is one of the major obstacles to its use on farms. The present study aimed to investigate the possibility of leaching heavy metals from wastewater sludge by Fenton method and determine the optimum level of parameters, such as iron, hydrogen peroxide, ...
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Background: High amount of heavy metals in sludge is one of the major obstacles to its use on farms. The present study aimed to investigate the possibility of leaching heavy metals from wastewater sludge by Fenton method and determine the optimum level of parameters, such as iron, hydrogen peroxide, time, and pH for Fenton reaction. Methods: The effects of various parameters, such as pH (2-9), hydrogen peroxide concentration (0.5-6 g/l), Fe concentration (0.5-4 g/l), and leaching time (5-60 min), were studied. Results: The results showed that the optimal condition for leaching of heavy metals occurred at pH of 2 3, hydrogen peroxide concentration of 3 g/l, iron concentration of 2 g/l, and leaching time of 15 min. Under these optimal conditions, 92% of Zn, 100% of Cd, 100% of Pb, and 80% of Cu were leached from the wastewater sludge. Conclusions: Fenton method can leach heavy metals from wastewater sludge through decomposition of organic materials at H2O2/Fe ratio of 1.5:2.
