The Adsorption Kinetics of
ABS on Fly Ash
K. H. MANCY, Assistant Professor
W. E. GATES, Assistant Professor
J. D. EYE, Assistant Professor
P. K. DEB, Research Assistant
Department of Civil Engineering
University of Cincinnati
Cincinnati, Ohio
The ever increasing demand for water of good to high quality has caused considerable attention to be directed toward the recovery or reuse of wastewaters.
Special attention has been given to the removal and the ultimate disposal of organic and inorganic contaminants which are resistant to removal by conventional
treatment processes; such contaminants are classified as refractory substances.
Among the several currently known physical, chemical and biological methods
used for wastewater renovation, adsorption has been indicated as the most promising technique for the removal of organic refractories (1).
The available literature pertaining to adsorptive processes used in wastewater
renovation deals primarily with activated carbon. The high organophilic character
of activated carbon has been recognized for a considerable period of time. Because of this characteristic, industrial and municipal water purification processes
presently constitute the largest market for activated carbon (2).
The organophilic nature of activated carbon also makes it an efficient scavenger of organic refractories in wastewater renovation operations. Nevertheless,
activated carbon has some technological as well as economical drawbacks. The
powder forms of activated carbon cost from seven to nine cents per lb and granular types cost from 25 to 50 cents per lb (3). These cost figures are of such magnitude that the only manner in which the use of activated carbon can be made
economically acceptable is through the development of a cheap regeneration
process. Recent studies using activated carbon in a column process showed a COD
removal of 12 per cent by weight. The initial cost of the activated carbon was
15 cents per lb. The cost of regenerating the carbon by chemical treatment was
90 cents per lb (4). Present studies are being conducted to determine whether or
not heat regeneration is a more economically acceptable process.
Recognizing the economic drawbacks of activated carbon other investigators
have studied the feasibility of using cheap commercial available materials as
potential adsorbents (5, 6). The materials used in these studies were a variety of
clays and minerals and industrial byproducts and wastes.
One of the cheapest and most available materials is "fly ash." This material
a waste product of the electric power industry, is produced in large quantities during the burning of powdered coal at high temperatures. A 1, 000 million watts
power plant will produce about 1,000 tons of fly ash daily. Estimates indicate
that during 1964 about 20 million tons of fly ash will be produced in the United
States.
In order to prevent air pollution, fly ash is collected by means of precipitators
from the flue gasses before they enter the stacks.   Fly ash, so collected, can not
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