Study Of The Mass Transfer Performance Of Removal Of Ammonia In Water By Membrane Distillation

Membrane Distillation (MD) is a new membrane separation technique. Using this technique to remove ammonia from water has great economical sense and causes no secondary pollution to environment. In this study, some aspects of removing ammonia from water by VMD, SGDM and DCMD were investigated. More attention was paid to the factors affecting the removal rate, the mass transfer coefficient and the selectivity coefficient of these processes.The membrane parameters which would be used in later membrane distillation experiment were measured by means of gas permeation experiments. During MD experiments, the titration using formaldehyde was applied to determine the concentration of ammonia in water.In the experiments of removing ammonia from water by VMD, two different kinds of PTFE membrane, whose mean pore diameter were 0.1 μm and 0.2μm respectively, were employed. The result of the experiments show that the mass transfer coefficient of 0.2μm membrane was much higher than that of 0.1μrn membrane, but the selectivity of 0.2μm...