PILOT-SCALE ANAEROBIC TREATMENT
OF PEROXIDE BLEACHERY WASTE, PAPER MACHINE EFFLUENT
AND WASTE ACTIVATED SLUDGE
Albert A. Cocci, Environmental Engineer
Robert C. Landine, Head, Environmental Engineering Division
Graham J. Brown, Environmental Engineer
Anne M. Tennier, Environmental Engineer
ADI International, Inc.
Fredericton, New Brunswick
Canada E3B 4Y2
INTRODUCTION
In mid-1984 ADI International Inc. was commissioned by a pulp and paper mill in the North
Central United States to carry out a five-month pilot-scale anaerobic treatability study. This followed
a successful six-week bench-scale study in which the treatability of bleachery waste (BW) and paper
machine effluent (PME) was assessed. The anaerobic technology chosen for the pilot study was an
ADI-BVF (bulk volume fermenter); this choice was made over the high-rate downflow filler. The
choice was based upon a number of advantages, viz.:
1. the BVF can handle waste activated sludge (WAS) at little or no extra cost, thus alleviating WAS de-
watering/disposal problems;
2. the BVF is less expensive to build and operate;
3. the BVF generates more energy in the form of biogas;
4. the BVF provides a high degree of influent solids removal and digestion;
5. the BVF provides a very significant degree of equalization because of its large volume and no additional
equalization is necessary; and
6. the BVF has a better payback since, in addition to lower capital costs and the savings accrued through
more biogas generation and reduced sludge disposal costs, it shouldn't require any nutrients and only
little, if any, chemical for pH control.
OBJECTIVES
The objectives of the pilot study were to confirm earlier bench-scale results showing treatability
of the bleachery waste and pulp mill effluent and to establish full-scale design criteria so that full-
scale capital and annual costs could be estimated.
PILOT-SCALE STUDY
Apparatus
The pilot plant apparatus, illustrated schematically in Figure I, consisted of:
• two 200-1 plastic drums for raw waste and feed storage;
• two variable-speed peristaltic pumps to deliver paper mill effluent and bleachery wastewater to the raw
waste barrel;
• a variable-speed feed mixer;
• a variable-speed peristaltic pump for feeding and recycling sludge to the ADI-BVF;
• adjustable timers to control the pumps:
• an ADI-BVF pilot reactor, 0.61 m diameter by 3.3 m long, 750-1 liquid volume, complete with influent
and effluent header systems, sample ports, provision for sludge/effluent recycle, thermometers, heaters,
thermostats, manually operated mixers and insulation;
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