59    PILOT TESTING AND DEVELOPMENT OF A
FULL-SCALE CARROUSEL® ACTIVATED SLUDGE
SYSTEM FOR TREATING
POTATO PROCESSING WASTEWATERS
Ravinder Menon, Senior Process Engineer
EIMCO Process Equipment Company
Salt Lake City, Utah 84110
Lloyd M. Grames, District Manager
EIMCO Process Equipment Company
San Mateo, California 94402
INTRODUCTION
Plant P is a major potato processor producing various types of frozen potato products. Figure 1
shows a simplified schematic of the plant's operation. As may be seen, wastewater comes from a
number of operations in the plant, including washing and peeling of potatoes and plant wash-
down. Wastewater from different sources at the plant is collected in a main sewer and sent for
primary treatment. Wastewater contains soil, potato peels, potato pieces of different sizes, fats,
oils and greases, detergents, cleaning agents, sanitizers and disinfectants, etc. Primary treatment
consists of floating grease removal, screening, and settling of solids.
Typical characteristics of the wastewater after primary treatment are as shown in Table I.
Land application using spray irrigation techniques was the final disposition of the primary effluent. Due to the high BOD, N, and P content of the wastewater, local environmental authorities
wanted this to be further cleaned up, due to concerns of contamination of soil, crops,-and
groundwater. Plant P came under increasing pressure to install secondary (biological) treatment
with nitrogen removal capability. After spending some time evaluating various options for biological treatment. Plant P was interested in investigating the feasibility of using the EIMCO Carrousel® system as their treatment means. This was mainly due to the fact that there are over six
hundred Carrousel plants in various industrial and municipal applications around the world, with
over three hundred in the U.S. alone and many had the added facilities for nitrogen removal. For
RAW
POTATOES
IN
PLANT  ^_
EFFLUENT
,~Y
FINISHED
POTATOES*
OUT
<S-C
Figure 1.    Plant P flow
schematic.
50th Purdue Industrial Waste Conference Proceedings, 1995. Ann Arbor Press Inc., Chelsea, Michigan 48118. Printed
in U.S.A.
545