[Laboratory-scale continuous treatment of monosodium glutamate manufacturing wastewater using yeast].

Dehydrogenation activity(DHA), test indicated that mixed yeast strains isolated from high strength monosodium glutamate wastewater could endure the high concentrations of COD, SO4(2-), and NH4+ containing in glutamate wastewater. The mixed yeast strains were inoculated to a biological contact oxidation reactor, and the reactor was used to treat the glutamate wastewater. Under a COD load ranging from 2.0 to 14.3 kg/(m3.d), the COD removal rate was over 80%. On the other hand, supplementation of phosphorus was necessary to maintain a stable COD removal performance. Variation of effluent pH seemed to have no apparent influence on COD removal rate. The optimum pH for the growth of yeast, however, was found to be in the range of 3.5-5.0. The effluent wastewater contained high concentration of yeast bodies, which could be utilized as a forage additive because of its high protein content (57.9%) and well-balanced amino acid distribution.