Chromium removal and water recycling from electroplating wastewater through direct osmosis: Modeling and optimization by response surface methodology
Journal Title: Environmental Health Engineering and Management Journal - Year 2019, Vol 6, Issue 2
Abstract
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.
Authors and Affiliations
Zohreh Naghdali1,2 , Soleyman Sahebi3 , Reza Ghanbari4,2 , Milad Mousazadeh1,2 , Hamzeh Ali Jamali4,2* 1Student
Keywords
Related Articles
- EP ID EP45472
- DOI 10.15171/EHEM.2019.13
- Views 347
- Downloads 0
Evaluation of trace elements contaminations in muscles of Rutilus kutum (Pisces: Cyprinidae) from the Southern shores of the Caspian Sea
Background: There is little information about the trace elements (TEs) concentrations in the muscle tissue of Caspian kutum (Rutilus kutum) in the South Caspian Sea. Methods: A total of 51 R. kutum specimens were caugh...
Risk assessment of noise pollution by analyzing the level of sound loudness resulting from central traffic in Shiraz
Background: Today, the effects of environmental pollution on human life and human needs, which reduces the level of community health caused by traffic noise in large cities, are clearly visible by creating irritation and...
Climate change and its effects on farm workers
Background: One of the biggest global occupational threats, especially in the outdoor workplace, is climate change and global warming, as workers are exposed to the heat stress leading to reduced performance. The aim o...
Evaluation of the impact of the COVID-19 pandemic on photochemical pollution in urban areas
Background: The effect of confinement due to the coronavirus disease 2019 (COVID-19) pandemic on air pollution has been investigated in several cities. Indeed, the concentration of the main air pollutants have decrease...
Effect of coagulation and sonication on the dissolved air flotation (DAF) process for thickening of biological sludge in wastewater treatment
Background: Dissolved air floatation (DAF) is one of the methods has been used for the sludge thickening in wastewater treatment plants. This study aimed to investigate the effects of coagulation and sonication process...