Evaluating Performance of a Nano-Filter in Removal of Arsenic Trioxide from Water

Abstract

Arsenic is a toxic element present in groundwater causing severe health issues, which require proper treatment before using groundwater for drinking purpose. A study was conducted to remove arsenic trioxide [As (III)] from groundwater using iron oxidecoated sand (IOCS). Batch study was conducted as a function of contact time (30 and 120 min), flow rate (1, 2, 4 and 7 l.h-1), thickness of filter media (50, 75 and 100 mm) for initial arsenic concentration (0.10 and 0.25 mg.l-1). Surface characteristics study of IOCS was done using scanning electron microscopy, Fourier transformation infra-red, energy dispersive X-Ray and X-Ray diffraction. Scanning electron microscopy showed the presence of iron oxide on the surface of coated sand, Fourier transformation infrared analysis showed the chemical bonding of iron at 525 cm-1 and energy dispersive X-Ray analysis showed 20.76 % of iron on coated sand. During study, maximum As(III) removal was 100 % for initial concentration of 0.25 mg.l-1 and 0.10 mg.l-1, respectively, for contact time of 120 min at flow rate of 1 l.h-1 for 100 mm thickness of filter material. Results of the batch study suggested that IOCS can be effectively used to achieve low level of arsenic in drinking water.