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ANAEROBIC PACKED COLUMN TREATMENT OF
SHELLFISH PROCESSING WASTEWATERS
James W. Hudson, Research Associate
Frederick G. Pohland, Professor
School of Civil Engineering
Georgia Institute of Technology
Atlanta, Georgia 30332
Richard P. Pendergrass, Project Engineer
William, Sweitzer and Barnum, Inc.
Rome, Georgia 30161
INTRODUCTION
Previous investigations regarding the treatability of raw shellfish-processing wastewaters
with conventional anaerobic methods have indicated only limited applicability [ 1,2]. Extensions of those studies to include contact recycle processes have demonstrated improved
organic removal efficiencies but treatment levels remained less favorable in comparison to
those resulting from aerobic applications [3]. Anaerobic treatment appeared to be largely
limited by the moderate to low organic strengths of the wastewaters investigated. These relatively low nutrient concentrations do not permit high biomass generation and retention
capacity under normal hydraulic loadings and thereby limit the effectiveness of conventional
anaerobic treatment applications which have been reported to require organic concentrations
approaching one percent before becoming economical [4].
Shellfish processing wastewaters for these investigations typically contained only 0.1-0.2
percent biodegradable material. Therefore, the anaerobic packed column (APC) or "anaerobic filter", demonstrated by others [5,6,7,8,9] to be effective for treatment of moderate
strength, soluble organic wastes, was chosen as a promising shellfish processing wastewater
treatment alternative. Moreover, since the configuration and nature of the APC provides for
significant biological solids retention capacities by solids accumulations within and on the
column packing material under economical hydraulic loadings, low capitalization and maintenance costs as well as minimal solids handling requirements and high substrate conversion
efficiencies could be anticipated.
PRELIMINARY CONSIDERATIONS
The purpose of this research was to establish the applicability of APC treatment for shellfish processing wastewaters and determine generalized design and operational criteria. Opportunities for comparisons of performance resulting from the use of conventional stone
packing and oyster shells, a locally available material, were included in the experimental design. The wastewater selected for experimentation originated from a Georgia coastal shellfish processing plant; the same wastewater source employed in previous physical-chemical
and biological treatability investigations [2,10].
EXPERIMENTAL SYSTEM
As indicated in Figure 1, two bench-scale, experimental anaerobic packed columns, each
fabricated from 15.24 cm I.D. by 152.5 cm plexiglass tubing with a packing media depth of
560