[Characteristics and influencing factors of ammonia contamination from production of monosodium glutamate].

Fluxes of ammonia contamination from production of monosodium glutamate (MSG) were quantitatively observed and relationships with some important influencing factors were statistically analyzed. The study indicates that there is a big difference in the release of ammonia at each step of MSG production including sewage treatment, depending on technical processes. The flux of ammonia released in the process of fermentation was highest, up to 880 mg x (L x min)(-1), and that in the process of refining sugar was lowest, only 0.07 mg x (L x min)(-1). Fluxes of NH3 emission during the whole process of MSG production are significantly related with the concentration of ammonium-nitrogen (NH4+ -N) in discharged solution linearly, and with concentrations of nitrate-nitrogen (NO3- -N) including nitrite-nitrogen (NO2- -N) in discharged solution exponentially. Although there is no linear relationship between fluxes of NH3 emission during the whole process of MSG production and pH values in discharged solution, it is significantly related with fluxes of NH3 emission during the process of sewage treatment.