EFFECT OF TEMPERATURE AND AIR-GAP WIDTH ON THE DESALINATION EFFICIENCY OF AIR-GAP MEMBRANE DISTILLATION MODULE

Abstract

Seawater desalination is a promising solution that can be applied to solve the problem of scarcity of freshwater and clean water in Vietnam, especially in islands and remote areas. Recently, the application of membrane distillation techniques for desalination has been attracting the attention of many scientists because of its simplicity, ease of operation and energy saving. An air-gap membrane distillation (AGMD) module was created on the basis of a low-density PE membrane with 12 x 5 cm size, porosity, width and average hole size was 85%, 76 µm, and 0.3 µm respectively. The width of the air space was controlled by the change in the number of plastic mesh in the permeability chamber. The results showed that the quality of permeate solution was identical with the quality of normal distillate water and the desalination efficiency of AGMD module strongly depended on the feed temperature, air-gap. The optimum condition found was 60 °C of feed temperature and air-gap width of 5 mm, then the water recovery flux reached 2.5 L.m^-2.h^-1.