65    PHOSPHORUS REMOVAL FROM A FOOD
MANUFACTURING WASTEWATER
Mervyn C. Goronszy, Director
Ying Bian, Senior Process Engineer
Transenviro, Inc.
Irvine, California 92718
INTRODUCTION
Food processing wastewater. Can generally be categorized as containing a high concentration of
CUU (greater than 1000 mgL"1) which is predominantly soluble (greater than 80%). It is not unusual
for these wastewaters to exhibit a deficiency of biologically accessible nitrogen or phosphorus or both '
These wastewaters can also have a high TSS and oil and grease content. Operation of activated sludge
facilities for nutrient removal from domestic wastewaters is becoming more commonplace The
operation of single sludge fed-batch reactor systems have been reported which demonstrate consistent
and reliable nutrient removal together with effective filamentous sludge bulking control '-2 These
involve cyclic aeration of a biomass in a compartmented variable volume reactor which serves to
accomplish biological degradation reactions and solids liquid separation (Figure 1). Appropriate
loading and repetitive cycling provides the mechanism for generating oxidation reduction potential
reaction conditions which associate with co-current nitrification-denitrification and phosphorus
removaL Performance of these systems depends upon maximizing intracellular storage of readily.
degradable soluble substrate fractions contained in the wastewater. Some form of oxygen regulation is
required in order to maintain the biomass at a level of metabolic activity that is required to sustain the
process Other procedures can also be used for nutrient removal whereby the activated sludge is
directed through successive anoxic, anaerobic and oxic zones in constant volume reactors which use a
clantier tor sohds-hquid separation. These are variously referred to as Bardenpho, A/O A2/0 UCT
and modified UCT systems. ' '
While low effluent nutrient concentrations for nitrogen and phosphorus are frequently required for
Publicly Owned Treatment Works (POTWs), more stringent nutrient requirements are also being
served on industrial dischargers which generally imply a "user pays" principle. In the near future it will
be more commonplace to see industrial pretreatment requirements and charges reflect nutrient con-
™:-as *e" aSuBOE;(COD)' TSS' P». etc- Particularly where nutrient removal is required of
the POTW to which the industrial facility discharges. A feature of activated sludge treatment of food
processing wastewaters using activated sludge has in many cases been an association with filamentous
sludge bulking particularly when using complete-mix reactor configurations. Filamentous species
associated with domestic wastewater nutrient removal treatment generally include types 0092 0914
iflrLuxni
-C
VOLUME I -CAPTIVE CONTACTOR
VOLUMEN - SECONDARY ZONE
VOLUME M • OXIDATION ZONE
Figure 1.    Schematic of 2 basin
CASS configuration.
4^^due Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed i
649