SIMPLIFIED KINETIC ANALYSIS OF THE
ANAEROBIC FLUIDIZED BED REACTOR
James A. Mueller, Professor
Environmental Engineering and Science Program
Manhattan College
Bronx, New York 10471
K. Subburamu, Engineer
Eugene J. Donovan, Jr., Principal
HydroQual, Inc.
Mahwah, New Jersey 07430
INTRODUCTION
A pilot study on anaerobic treatment of the foul condensate from an ammonia based spent sulfite
liquor evaporator has recently been conducted at the Procter & Gamble Paper Products Plant in
Mehoopany, Pennsylvania. The study involved construction of pilot plants representative of three
technologies commercially available with a seven month (January to July 1983) pilot plant program
to compare their performance. The three pilot systems studied were the anaerobic filter, the anaerobic
upflow sludge blanket (contact) bed, and the anaerobic fluidized bed.
A significant quantity of data was obtained on the fluidized bed system over the study period
encompassing a wide range of reactor loading rates, biological solids concentrations and effluent
concentrations. Although the collection of detailed data to allow an in-depth kinetic analysis of the
system was not an objective of the study, the data available provided an opportunity to obtain a
better understanding of system performance as related to biological solids growth rate and biological
solids and substrate concentrations.
This paper presents the development and results of the kinetic analysis on the anaerobic fluidized
bed reactor along with a brief summary of the removals obtained on the three systems studied. A
detailed summary of the results on the three systems can be found in Donovan et al [1] and should
be available in an EPA 1ERL report after final reviews.
PILOT PLANTS
Figure 1 is a simplified schematic illustrating the pilot plants, which were set up in a building near
the evaporator. A small side stream sample from the main condensate line was cooled and piped to
two 4000 I stainless steel holding tanks. Nutrients and neutralizing chemicals were added to the waste.
Positive displacement pumps fed waste into the recycle stream of each reactor. The fluidized bed had
a reactor zone of 28 to 41 liters in volume, contained sand media averaging 0.5 mm was 15 cm in
diameter by 3.7 m high with an expanded bed depth of 150 to 230 cm. The sand media occupied
about 14.6 liters of volume until days 186 and 189 when relatively inert media at the bottom was
removed. From day 190 to 207, the sand media occupied about 9.7 liters of reactor volume. Each
100 cm of reactor height contained 18.2 liters of total volume. The anaerobic filter had a reaction
zone of 1.35 cubic meters, 3 meters deep, and contained 9 cm flexi-ring media. The reactor was 75
cm in diameter by 3.7 m overall height. The upflow sludge blanket overall dimensions were the same
as the filter; however, the reaction zone was 1.2 cubic meters, contained no media and had an internal
gas-liquid separator, and solids settling zone. These two reactors were provided with effluent clarifiers
and sludge return pumps for optional use. Temperature in the units was maintained by recirculating
effluent and influent flow through temperature controlled electric heat exchangers and heating tapes
on the large reactor shell. Gas from the reactors was measured with wet test meters prior to venting.
599