Biological and Physical-Chemical Treatment of Waste
From a Diversified Organic Chemical Plant
JOHN H. KOON, Director of Wastewater Management
CARL E. ADAMS, Jr., President
Associated Water and Air Resources Engineers, Inc.
Nashville, Tennessee 37204
BACKGROUND INFORMATION
Wastes produced during the manufacture of organic chemicals are extremely difficult
to categorize due to the multitude of substances contained in this classification.
Nevertheless, wastes discharged from many plants may be described once the intermediates
and final product produced in the plant have been identified. The identification of
applicable treatment processes in such situations may usually be made following an
appraisal of the types of organics present in the wastestream. For plants in which the
product mix remains the same over long operating periods, established procedures may be
used to identify treatment characteristics of the waste in order to develop the most
optimum treatment sequence.
However, many plants in the industry have been designed to produce a wide variety of
products in order to supplement production at other plants or to manufacture specialty
chemicals. In these plants, the product mix usually changes significantly on a weekly or
monthly basis. Wastes from these plants typically contain significant concentrations of
more complex organic substances. In comparison to municipal sewage, these wastes are
highly variable in composition, depending on plant production schedules, and are
composed principally of soluble organic substances which cannot be removed by
precipitation or adsorption onto biological floes and may contain exotic chemical species
which would interfere with conventional treatment processes. When treating wastes of this
type, biological processes would be most effective in removing short-chained and other
degradable organic constituents, while physical and chemical processes, such as adsorption
using activated carbon, would be required to remove substances refractory to biological
treatment.
The plant studied during this investigation is a multi-product organic chemicals plant
in which over 500 different raw materials are used to make more than 200 different chemical
products. Products manufactured in the plant include plastic additives, pharmaceuticals,
dye stuffs and intermediates, and miscellaneous chemicals. The products produced are used
largely in the plastics, leather, textiles, and paper industries.
The complexity of waste treatment problems in the plant is indicated by the large
number of products produced in the facility and by the variety of manufacturing processes
employed. Production of the great number of products required from this plant necessitates
the use of batch processing methods which usually generate greater quantities of waste than
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