28-10-2009, 08:04 PM
Bio-oxidation treatment was a final step in cleaning excess process
water or waste ammonia liquor that originated from coke oven gas
produced during the coking process
In this process, phenol and thiocyanate were "eaten" (oxidized to carbon
dioxide and water) by bacteria at a bio-oxidation plant. The treated
water was then sent to the City of Bethlehem's municipal sewage
treatment plant where the remaining ammonia was "eaten" by a yet another
strain of bacteria and made safe to discharge into the Lehigh River
The bio-oxidation plant operation consisted of four main units: a large
treated weak-liquor holding tank, a mix box, a rectangular aeration
basin, and a pair of round clarifier ponds.
Before bio-oxidation actually began, process water was held at the
treated weak liquor holding tank to equalize possible fluctuation of
ammonia so that it does not adversely affect the rate of phenol
oxidation. Process water was water used in cokemaking. From a holding
tank, process water flowed to a mix box where an antifoam agent,
phosphoric acid (a nutrient required by the bacteria), and dilution
water were added. At this stage, process water was ready to begin
bio-oxidation