Performance enhancement of membrane distillation in the desalina-tion of sea water and brackish water

In order to meet people's increasing demand for water, it is urgent to transform undrinkable water resources such as seawater and brackish water into water suitable for human use. Membrane distillation has become a water treatment technology with great development potential due to its advantages of high desalination rate, good water quality, high water recovery and low operating cost. It can effectively solve the problem of desalination of seawater and brackish water, and has broad application prospects in solving the shortage of fresh water resources. However, membrane fouling and polarization effect limit the performance of membrane distillation in seawater desalination. This paper briefly describes the working principle of membrane distillation technology, analyzes the formation mechanism of polarization effect and membrane fouling, and introduces the technical methods for enhancing the performance of membrane distillation. In addition, the future research direction of membrane distillation is prospected.