Treatment of
Organic Industrial Wastes by Lagooning
ROBERT C. COOPER, Assistant Professor
WILLIAM J. OSWALD, Associate Professor
JOSEPH C. BRONSON, Research Assistant
School of Public Health and College of Engineering
University of California
Berkeley, California
The rapid increase in the nation's already vast output of industrial wastes, together with commingling of agriculture, industry, and residential areas, and
progressively higher environmental standards, have resulted in increasing demands
for economical and reliable methods of liquid waste disposal. The most promising solution to many of these problems is the treatment of liquid industrial wastes
in well-designed and operated oxidation ponds or lagoons.
Experience in California has shown the applicability and feasibility of such
ponds in the effective and economic treatment of industrial and agricultural, as
well as domestic wastes. Ponds are not a panacea to all waste problems, however,
and this paper should not be considered to contain such implication. Many examples of ill-conceived, poorly designed, badly constructed, and improperly
managed ponds can be found to support the hypothesis that ponds should not always
be used. But there are increasirg numbers of well-engineered, excellently constructed, and properly managed ponds, which are a distinct credit to our increasing understanding of the biological, physical, and chemical basis for their applicability and design. Such understanding has led to modifications of the ancient
lagoon design concept, of a simple "hole in the ground." For example, it has
now become evident that in certain instances judiciously applied mechanical
mixing can greatly enhance performance and reduce the potential for nuisance
odor production in ponds. It has also become evident that in many circumstances
some type of pretreatment is beneficial before lagooning is used and that systems
of ponds can give performance far superior to that of single units. Land cost and
area availability will obviously always be an important factor in deciding the
utility of ponds in a given waste treatment problem.
In California we have been concerned with broad applications of ponds and
have maintained active studies of three types of ponds: anaerobic, facultative,
and aerobic which, singly or in combination, may be applicable to the treatment
of most industrial wastes.   A brief description of each type of pond follows.
ANAEROBIC PONDS
These ponds are loaded to such an extent that any dissolved oxygen present is
quickly consumed due to microbial action, and therefore anaerobic conditions
prevail throughout the liquid volume. The BOD applied is removed during waste
residency in the pond primarily in the form of methane and hydrogen. Essentially
the same processes are involved as those encountered in a conventional, unheated
anaerobic digester (see Figure 1). The main advantage of this type of pond is the
use of high organic loading rates on relatively small land areas due to increased
pond depth.    Another important advantage is the low capital cost as compared to
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