Study on the Experiment of Concentrating Coking Wastewaters by Air-blowing Vacuum Membrane Distillation

In the article, a new air-blowing vacuum membrane distillation (AVMD) process is proposed, and it forms the air-liquid flows in the membrane by forcedly blowing airs to the hot feed liquids circularly flowing in the hollow fiber membrane, and forms the AVMD system to enhance the turbulent degree of the liquids. The intense disturbance of air bubbles and the strong cutting power at the surface of membrane can reduce the depth of the boundary layer of liquids, the temperature and the concentration polarization of the membrane surface, and enhance the speed of heat and mass transfer to enhance the membrane distillation flux and control the membrane pollution. By the process that the optimized AVMD process is used in the coking wastewater treatment process of certain enterprise, the influence of the pretreatment technique of the wastewater on the removal effect of COD is studied in the article, and the influences of the vacuum membrane distillation (VMD) and the AVMD process on the wastewater concentrating treatment effect and efficiency are also respectively researched in the article.