Study on the Concentration Process of Glutamic Supernatant Fluid by Vacuum Membrane Distillation and the Reuse of Product Water

The optimal decoloring conditions for glutamate supernatant in orthogonal experiment are: 15g/l bentonite concentration, 2h decoloring time, and 40°C decoloring temperature. VMD technology can concentrate glutamate supernatant filtrate from 2.01% to 5.35%, and bring down flux from 6.71 L/m2h to 1.94L/m2h, at a concentration rate of 1.72 times. The glutamic acid concentration in supernatant fluid is enriched from 2.03% to 5.16%, and flux attenuated from 5.47 L/m2h to 1.91 L/m2h. As glutamic acid concentration in supernatant increases, membrane flux gradually decreases. Analysis of water production in glutamate supernatant membrane distillation and the meteorological chromatograms of glutamic acid filtrate prove that the difference between water-yielding peak time of supernatant fluid and that of the filtrate is less than 0.1 min. The volatile substances during water production are from glutamic acid filtrate and are of the same matter. Therefore, the product water in supernatant fluid membrane distillation can be reused to improve water production efficiency.