Treatment of Urban Runoff Using Manganese Oxide-Coated Sand in Presence of Magnetic Field

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Abstract

Abstract Background : Increase of impervious surfaces in urban areas in addition to increasing volume and runoff peak, increases the variety of type and quantity of pollutants in urban storm water. Polluted runoff has many adverse impacts on human health and the environment. The purpose of this study was to investigate the efficiency of manganese oxide oxide- coated sand in presence of magnetic field to treat urban runoff. Methods: In this study , a plexyglass column filled with manganese manganese- coated sand and with two magnets in its proximity proximities was used to treat the runoff. and t T he flow was continuous and downwards. Before and after the runoff sample pass ed ing the column and after sufficient retaining time the samples were checked in regard to lead (Pb) , zinc (Zn) , turbidity, pH, nitrates , and phosphate. Scanning electron microscope ( SEM ) SEM and Energy dispersive X-ray (EDAX) EDAX analysis were used to determine of the change s in the coated sand surface and the percentage of sand components , respectively. Results : SEM ( Scanning Electron electron M m icroscope ) and EDAX ( Energy Dispersive dispersive X - ray ) analyses confirmed that the sand had been coated with manganese oxide successfully. Results indicated that turbidity, Pb, Zn and phosphate removal efficiency by the coated sand in presence of magnetic field were 89.6, 65.9, 81.1 and 67 percent, respectively; and that the coated sand was not able to remove nitrates. Conclusion: Manganese oxide-coated sand filters , in presence of magnetic field , improve the quality of urban runoff significantly. This could be a promising treatment technology that can enhance the quality of urban runoff and industrial wastewaters which have with heavy metals. Key word s : Urban runoff, manganese Manganese oxide, sand Sand filter, magnetite Magnetite field