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

摘要

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 polyvinylidene-fluoride (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 m~3/h, the 0.13 μm PVDF membrane yielded a high flux of 74 kg/(m~2 h) at a feed water temperature of 40 ℃ and, 95 kg/m~2 h at a feed water temperature of 60 ℃. 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.