Chromium removal and water recycling from electroplating wastewater through direct osmosis: Modeling and optimization by response surface methodology
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Zohreh Naghdali , Soleyman Sahebi , Reza Ghanbari , Milad Mousazadeh , Hamzeh Ali Jamali |
Corresponding author: Department of Environmental Health Engineering, School of Health, Qazvin University of Medical Sciences, Qazvin, Iran , jamalisadraei@yahoo.com |
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Abstract: (5810 Views) |
Background: Considering the carcinogenic effects of heavy metals, such as chromium, it is essential to remove these elements from water and wastewater. Direct osmosis is a new membrane technology, which can be a proper alternative to conventional chromium removal processes.
Methods: The wastewater samples were collected from an electroplating unit, located in Alborz industrial city, Qazvin, Iran. Magnesium chloride was used as the draw solution, and a semipermeable membrane (Aquaporin) was used in this study. The experiments were designed, using response surface methodology (RSM) and central composite design (CCD) with draw solution concentration (0.5- 1.5 M), feed solution concentration (4-12 mg/L), and experiment time (30-90 minutes) as variable factors. The chromium concentration and water flux were also measured, based on atomic absorption spectrophotometry and water flux equation, respectively.
Results: Direct osmosis was highly efficient in chromium removal and water recycling. Water flux and chromium removal efficiency were 15.6 LMH and 85.58%, respectively, under optimal conditions (draw solution = 1.27 mol/L, feed solution = 4 mg/L, and experiment time = 90 min). In terms of validity,
the results predicted by the quadratic polynomial model were in good agreement with the responses reported in the laboratory.
Conclusion: In direct osmosis, the use of magnesium chloride as the draw solution resulted in the acceptable chromium removal from electroplating wastewater. Using this method, chromium concentration in wastewater reduced to a level lower than the discharge standards, established by Iran’s
Department of Environment. |
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Keywords: Direct osmosis, Chromium removal, Electroplating, Optimization eprint link: http://eprints.kmu.ac.ir/id/eprint/31293
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Full-Text [PDF 1186 kb]
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Type of Study: Original Article |
Subject:
Special Received: 2019/06/26 | Accepted: 2019/06/26 | Published: 2019/06/26
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