CHARACTERIZATION AND TREATMENT OF YEAST PRODUCTION PROCESS EMISSIONS IN A BIOFILTER

Characterization of odorous VOC emissions in waste gas stream and removal of characterized pollutants with a proper technique become prominent. Within this study, bakery yeast fermentation emissions were analyzed with both instrumental and olfactometric methods to illustrate emission characterization in terms of both objective and subjective views and were biodegraded in a pilot scale biofilter. Instrumental analyses determined the chemical composition of emissions where ethanol emission was reached to 764 mg m(-3) at peak hour, which were followed by acetaldehyde (331 mg m(-3)) and acetone (65 mg m(-3)). Olfactometric analyses were carried out to quantify the sensory impact of odors and the odor concentration was measured at peak hour as 39725 OU m(3), which resulted 40 times higher concentration than legal limits. Process emissions were treated in a pilot scale biofilter primarily for single ethanol load and achieved to maximum removal of 97 +/- 1 % with an elimination of 31.7 +/- 1.2 g m(-3) h(-1) while ternary waste gas stream simulation within addition of acetaldehyde and acetone to synthetic stream resulted to removal of 92 1 %, 86 +/- 2 %, 62 +/- 1 % with elimination of 38.5 +/- 1.9 mg m(-3), 12.4 +/- 1.1 mg m(-3), 2.5 +/- 0.3 mg m(-3) for ethanol, acetaldehyde and acetone, respectively. In brief the superior performance of biofilter operation were achieved for both single and ternary gas streams from process emissions while still process improvement on VOC mass transfer enhancement for high waste gas flow will be required.