直接接触式膜蒸馏脱盐的实验研究

he membrane distillation experiments were carried out by using PVDF hollow fiber hydrophobic membrane of pore size 0.6μm in this paper. Both 0.6mol/L and 1.0mol/L NaCl solution and deionized water were used as the feed of membrane distillation to investigate the effects of hot-side temperature, hot-side solution concentration and cold- and hot-side flow rates on the membrane permeate flux in a direct contact-type membrane module, to find out the optimum operation condition of desalination by direct contact membrane distillation (DCMD) and to provide experimental evidence for actual industrial applications. The results showed that for NaCl solution the lower the hot-side solution concentration, the higher the membrane flux, but the effect of the NaCl concentration on the membrane is minimal; it is analyzed from economic perspective that the operational condition of membrane distillation was best when hot-side temperature was controlled at 55℃ and cold-side temperature was maintained at 25℃, at the same time cold- and hot-side flow rates were controlled at 0.1 m / s and 0.8m / s, respectively.