ABSTRACT
Elemental balances of microbial growth have been applied to calculate (C/N) ratio in a denitrification process. The correlation between biomass yield coefficient and degree of reduction has been used to estimate the critical (C/N) ratio. It has been shown that when the degree of reduction of the substrate is lower than 4.67, the critical value of (COD/N) is almost constant and equals 7.6 g O2 g(-1) N. The batch cultures of denitrifying bacteria Ervinia sp. on glucose, sodium acetate and methanol have been used to verify theoretical relations. The results of experiments generally agree with theoretical considerations.
Subject(s)
Bioreactors , Carbon/metabolism , Nitrates/metabolism , Nitrogen/metabolism , Water Pollutants, Chemical/metabolism , Bacteria/isolation & purification , Bacteria/metabolism , Carbon/analysis , Glucose/metabolism , Methanol/metabolism , Nitrates/chemistry , Nitrogen/analysis , Sodium Acetate/metabolism , Time FactorsABSTRACT
A number of industrial processes require the addition of materials to the fermentation broth that are hazardous to health and environment. Agitation of broths inoculated with microorganisms can potentially release aerosols large enough to carry the microorganisms. The influence of agitation, air flow, and bacterial growth on aerosol size distribution, air flow, and bacterial growth on aerosol size distribution was investigated in an industrial pilot scale fermentor. A decrease in particle concentration was observed with increase in bacterial growth; this change was more pronounced in the size range above 2 microm. The aerosol size distribution was found to be practically independent of air flow rate and agitation rate for sizes less than 2 microm. However, for particles larger than 2 microm, the concentration was found to increase with an increase in air flow rate and agitation rate.
