Removal of arsenic from contaminated groundwater by solar-driven membrane distillation.

Experimental investigations were carried out on removal of arsenic from contaminated groundwater by employing a new flat-sheet cross flow membrane module fitted with a hydrophobic polyvinylidenefluoride (PVDF) microfiltration membrane. The new design of the solar-driven membrane module in direct contact membrane distillation (DCMD) configuration successfully produced almost 100 per cent arsenic-free water from contaminated groundwater in a largely fouling-free operation while permitting high fluxes under reduced temperature polarization. For a feed flow rate of 0.120 m3/h, the 0.13 microm PVDF membrane yielded a high flux of 74 kg/(m2h) at a feed water temperature of 40 degrees C and, 95 kg/m2h at a feed water temperature of 60 degrees C. The encouraging results show that the design could be effectively exploited in the vast arsenic-affected rural areas of South-East Asian countries blessed with abundant sunlight particularly during the critical dry season.