K. Acuna-askar et al., Methyl tertiary-butyl ether (MTBE) biodegradation in batch and continuous upflow fixed biofilm reactors, WATER SCI T, 42(5-6), 2000, pp. 153-161
MTBE was effectively biodegraded under oxidizing environmental conditions i
n the presence of an acclimated mixed culture isolated from a petrochemical
biotreater. MC-1 (Gram-positive coccus), MC-2 (Acinetobacter Iwoffii) and
MC-3 (Bacillus sp.) were present in the culture medium, with MC-1 being the
predominant organism. The presence of other easily assimilated carbon sour
ces in the culture medium influenced MTBE biodegradation. In batch studies,
62-73% MTBE was biodegraded in 144-192 hours at an initial concentration o
f 100 ppm as the sole carbon source, with the ORP ranging from 191-274 my,
and at a temperature of 29 degreesC. The overall K rate constants and the s
pecific k rate constants were evaluated using a first or der rate equation.
Mean values determined were 1.79x10(-1) day(-1) and 1.66x10(-2) day(-1)/(m
g/L cell mass), respectively. Continuous upflow fixed biofilm reactor studi
es were performed at retention times of 0.25, 0.5, and 1 day at an initial
MTBE concentration of 150 ppm. Results indicated that approximately 53% MTB
E was biodegraded for the 0.25 day retention time and 70% for both the 0.5
and 1.0 day retention times. Three kinetic models were evaluated for all ex
perimental retention times. These included: Model I (Eckenfelder); Model II
(Arvin) and Model III (first-order biphasic). Results indicated that model
III yielded the highest and most consistent correlation coefficients for a
ll retention times evaluated.