Aeration Film Evaporation Crystallizer Process

At present,the shortage of water resources has restricted the economic and social development of our country,and the improper treatment of industrial waste water or even the discharge of random,we live in a serious environment.Every year a large amount of industrial wastewater is produced in China and the world,so it is an important problem to be solved in the world.Due to the shortage of water resources,seawater desalination and zero brine discharge technology are closely watched.Crystallizers have been placed on the promise of zero emissions for their ability to recover resources from concentrated brine.However,the traditional industrial metal crystallizers are prone to corrosive metal materials and cover a large area.As a new crystallization technology,membrane distillation has been widely concerned becauseof its large evaporation area and high efficiency.However,there are still some problems such as scaling with fouling of the membrane and wetting of the hydrophobic membrane.This paper presents a new type of membrane crystallization process-aeration membrane crystallization process(AMC),according to the principle that the ability of air absorbs moisture are different at different temperatures,the hollow fiber hydrophobic membrane is used to aerate the feed solution to enhance the evaporation of the feed liquid,it can achieve the concentrated crystallization of the concentrated brine and avoid the corrosion of the metal crystallizer and the membrane distillation pollution problem.In this paper,the strengthening effects of membrane aeration on liquid evaporation,the effect of aeration intensity on crystal formation,the influence of gas-liquid separation distance on water quality and the long-term stability of the system were investigated.In addition,the factors that affect the operation of the process were further explored.The experiment shows that the membrane flux can reach 16.4 kg/(m2 h),the water conductivity can be around 20 ?S/cm,crystal particle size distribution(80-110 ?m).The results show that hydrophobic micro-porous membrane aeration treatment was carried out on the feed solution has the advantages of resistance to pollution and corrosion,integration of pure water output and solution crystallization,control the crystal size,convenient operation,long-term stable operation and so on.The process provides a new idea for the preparation of all-plastic crystallizer to achieve zero-emission concept.