Oxidation of organic compounds may be
incomplete, with acetate (often simultaneously with CO2) as a
potential by-product; or it is a complete oxidation, leading to the
final production of CO2. Dissimilatory biological sulfate reduction
is a process carried out by many bacteria and some archaea [9]. In
such environment, simple compounds (ethanol, methanol, acetate
and H2/CO2) seem to be preferred over complex substances [10].
Ethanol was found to be a suitable carbon and energy source for
sustaining sulfate reduction in such anaerobic reactors. The use of
ethanol in sulfate-reducing systems has already been applied in
full-scale plants [11,4] in lab-scale UASB [12] and in a fluidized bed
reactor [13].