Treatment of High Strength Citrus Wastewater
With High Purity Oxygen Activated Sludge Process
MURLI TOLANEY, Supervising Engineer
James M. Montgomery, Consulting Engineers, Inc.
Pasadena, California 91101
INTRODUCTION
With the increasing emphasis on water pollution control and stringent requirements
imposed by regulatory agencies, industries are finding it necessary to initiate waste control
programs, make inhouse changes or construct treatment facilities to meet new discharge
requirements. The Lemon Products Division Plant of Sunkist Growers, Inc. is located in
the City of Corona, California, 47 miles east/ southeast of Los Angeles. The plant processes
600 to 1,200 tons of lemons per day to produce over 300 different lemon products including;
juice concentrates, pectin, several forms of peel, lemon oil, dried peel products and beverage
bases. The industry is one of several who have continued to modify, improve and upgrade
its wastewater disposal practice. This paper will attempt to characterize the composition of
the wastewater, indicate the wastewater disposal practices and problems, describe the type
of pilot plant studies undertaken and summarize the design-criteria for a full scale treatment
facility.
WASTEWATER CHARACTERISTICS AND DISPOSAL PROBLEM
The wastewater at the Lemon Products Division (LPD) is created by the washing and
squeezing of lemons, extracting oils, floor washings, peel processing and pectin production.
There are several wastewater streams originating from different processes, which vary in
organic and inorganic content. The composite wastewater, however, is very high in organic
content, total dissolved solids (TDS) and suspended solids (SS).
For the past several years, the plant has disposed of its wastewater on a 290-acre farm.
The California Regional Water Quality Control Board has continually questioned this
disposal practice and has finally set effluent discharge requirements which preclude its
continued use. The discharge requirements contain both organic and inorganic constituent
limitations. Table I gives LPD's wastewater quality prior to any treatment and the Board's
requirements for wastewater to be spread on the farm.
In order to develop a process to meet both the organic and inorganic limitations several
laboratory and pilot scale studies using reverse osmosis processes were conducted.
Although this process removed both the organic and inorganic constituents sufficiently,
membrane fouling and low permeation rate resulted in its discontinuation.
More recently, use of a brine line (Santa Ana Regional Interceptor) to convey the
wastewaters with high salt content had been proposed. Waste from this line would receive
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