Removal of arsenic from contaminated groundwater by solar-driven membrane distillation using three different commercial membranes

摘要

Investigations on solar-driven membrane distillation (SDMD) were carried out for removal of arsenic from contaminated groundwater. Three different types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polypropylene (PP) with surface area of 120 x 10~(-4) m~2 were used as flat sheet in a direct contact membrane distillation (DCMD) set up in a cross flow module. Effects of initial arsenic concentration in the feed, feed velocity, feed temperature and distillate inlet temperature on arsenic removal efficiency and flux were studied where temperatures of feed and distillate were found to have significant effect on the flux. Almost 100% arsenic separation was achieved without wetting membrane pore even after 120 h of operation. The PTFE membrane with a flux of 49.80 kg/m~2 h was found to the best one out of the tested membranes. The study shows that solar-driven DCMD can effectively separate arsenic from groundwater using a cross flow membrane module with PTFE hydrophobic membrane.