Method for treating high-salt water by air stripping type membrane distillation

Abstract

The invention provides a method for treating high-salt water by air stripping type membrane distillation. In the method, an air compressor is arranged in the system, a hydrothermal circulation pump and the air compressor jointly generate a gas-liquid two phase flow on a high-temperature side of a hydrophobic membrane, an electromagnetic valve is arranged on an air pipe, and pulse air intake is formed by the intermittent opening and closing of the electromagnetic valve. The method can effectively control membrane pollution and ensures the stable and high-efficiency operation of a membrane distillation device. The method has the main advantages of effectively relieving the concentration polarization of membrane distillation and preventing the formation of a gel layer due to the scraping effect of air bubbles on membrane surfaces in the gas-liquid two phase flow, and improving the turbulence scale of the membrane surfaces, increasing the membrane surface flow rate, reducing the concentration of membrane surface salt solution and increasing membrane permeation flux due to the adoption of pulse air intake. Air passing through a membrane component can be used for cooling membrane distillation penetrating fluid. The method of the invention can treat salt water with an extremely high concentration.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a method for water treatment, especially water desalination treatment, using air lift technology and membrane distillation technology. Background technique [0002] With the development of economy and the growth of population, the shortage of water resources has become a global problem, and the situation of water shortage in our country is particularly severe. my country's per capita water resources are only equivalent to 1 / 4 of the world's average level, and it is one of the 13 countries with very few water resources in the world. Among the more than 600 cities in the country, nearly 400 are short of water, and more than 130 of them are seriously short of water. At the same time, a large amount of waste water is directly discharged without treatment, causing serious water pollution and exacerbating the shortage of water resources. In terms of high-salt wast...

AI Technical Summary

Problems solved by technology

But so far, direct contact membrane distillation has not been applied on a large scale. The main reasons are: high energy consumption leads to high operating costs; membrane-salt solution interface temperature polarization reduces the water flux of the membrane; long-term operation process Membrane fouling leads to a decrease in membrane efficiency

[0005] In recent years, research on membrane distillation has focused on reducing operating energy consumption and exploring the applicable fields of membrane distillation. There are few researches and reports on membrane fouling.

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