The effect of salinity on the removal of some aliphatic ketones

Abstract

Basic and definitive information pertaining to the effect of salinity on the microbial behavior is essential to determine the fate of organic pollutants discharged in to the estuaries, and to determine design and operation parameters of plants subjected to salinity variation. Twenty-five batch tests were run to determine the long and short term effect of salinity variation on the microbial behavior of cultures established in various salinity levels and tested under different salinity conditions. Aliphatic ketones namely, acetone, 2-butanone and 2-pentanone were used as a carbon source in this study because of their appearance in many industrial wastes. Mixing and aeration was accomplished by using the Incubator shaker. Samples were withdrawn periodically and analyzed for the concentration of organisms, concentration of each of the original substrates, total organic carbon, oxygen uptake rate and pH. A hydrogen flame gas-liquid chromatograph, total organic carbon analyzer, and Gilson oxygraph were the primary analytical tools used for this study. Data from batch tests were analyzed and the following conclusions were formulated. 1. The decrease in the substrate removal rates was proportional to magnitude of the salinity shock. 2. The oxygen requirement per unit ketone removed increased for a culture acclimated to a certain salinity and shocked with lower salinities. 3. The biomass increase per unit ketone removed was higher for cultures established and tested at low salinities. 4. The effect of long term salinity studies clearly indicated that cultures established in fresh water and low salinities have a higher u n it rate of removal than the cultures established at greater salinities . 5. The removal of 2-butanone and 2-pentanone occurred first in all test series. The acetone removal started when the concentration of the other two ketones reached low levels 5 mg/1)..