Aerobic Secondary Treatment of Potato
Processing Wastes
GLENN A. RICHTER, Project Manager
ROBERT E. PAILTHORP, Division Manager
CH2M/HILL
Engineers-Planners-Economists
Corvallis, Oregon
K. LYNN SIRRINE, Research Chemist-Project Supervisor
The R. T. French Company
Shelley, Idaho
INTRODUCTION
Aerobic secondary treatment systems were studied at the R. T. French
Company in Shelley, Idaho, during the 1969-70 potato processing season to
determine their efficiency in treatment of potato processing wastes. These studies
were supported by an Environmental Protection Agency demonstration grant.
The primary objectives of the study were to: 1) Demonstrate the feasibility of
secondary treatment of potato processing wastewater with activated sludge; 2)
Determine the BOD removal efficiency and effluent characteristics when the system
is operated at predetermined MLSS (mixed liquor suspended solids) levels; 3)
Determine the quantity and characteristics of the waste activated sludge; 4)
Demonstrate the effectiveness of a clarifier-thickener and disc filter system in
removing and concentrating waste activated sludge and silt; 5) Determine
construction costs, operation problems and costs, treatment efficiency, maintenance
problems and costs, and silt and waste activated sludge disposal problems and costs;
and 6) Establish the influence of foam, ice, temperature, pH, nitrogen, phsophorus,
flow interruptions, and processing plant shutdowns on the treatment system.
Operation and cost data included in this report are for the secondary treatment
facility only. Primary treatment of the process wastewater is provided at the
processing plant and has not been evaluated in this study. Silt removal costs are
included.
Cornell, Howland, Hayes & Merryfield, Consulting Engineers, were retained by
the R. T. French Company to design the facility and to furnish technical supervision
during the demonstration of the system.
PLANT DESCRIPTION
Potato processing plant wastewater can be divided into two major streams; 1)
silt water, and 2) process water. The silt water results from raw potato washing and
fluming operations. It contains large amounts of soil removed from the raw potatoes.
Process water results from potato processing operations, where raw potatoes are
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