RESOURCE RECOVERY AND SOURCE CONTROL VIA
ACTIVATED CARBON ADSORPTION WITH
INPLACE NONDESTRUCTIVE REGENERATION
Charles S. Parmele, Environmental Specialist
Robert D. Fox, Engineer
Hydroscience Environmental Systems
Knoxville, Tennessee 37919
INTRODUCTION
Since wastewater treatment costs wUl continue to go up in the future, the abUity to
offset the cost of pollution control through resource recovery is an attractive objective.
On one hand, advanced wastewater treatment will be necessary to achieve compliance with
forthcoming EPA regulations to restrict the discharge of specific "priority pollutants."   On
the other hand, the incentive for resource recovery has been and will be continually changing due to escalating prices and/or shortages.   Evaluations need to be updated to reflect
changing conditions.   For example, Table I shows that price increases made recovery of
phenol and acetic acid more economically attractive in 1975 than in 1973.
Table I.   The New Economics of Recovery
1975 vs 1973
Phenol $0.30/lb $0.06/lb
Acetic Acid $0.15/lb $0.06/lb
Thus, processes which achieve compliance with discharge regulations and improve resource recovery are attractive now and wUl be even more so in the future.
IN-PLACE NONDESTRUCTIVE REGENERATION
The abUity of activated carbon to achieve low effluent concentrations for many of the
"priority pollutants" or materials like them is known.   However, even though loading
capacities for specific compounds are often excellent, the universal application of activated
carbon for tertiary treatment is not always the best choice.   Loadings are often reduced
in complex waste mixtures because of the relatively low concentrations and the presence
of other organics.   Another disadvantage of end-of-the-pipe applications is the usually impossible task of separating chemicals from each other for recycle.   Often, therefore, a better choice is to use adsorption to separate pollutants from individual waste streams where
loadings are higher due to higher concentrations and to less complex wastes and where
separation of recoverable materials is much easier.
The effective use of activated carbon is dependent on effective carbon utilization.   Often
in the past, adsorption has been limited to low feed concentrations because when used for
concentrated wastes the activated carbon is saturated quickly, often within days instead of
weeks or months.
Although thermal regeneration is usually effective, it would be prohibitively expensive
for concentrated industrial wastes. In 1969, Dow recognized that in order to efficiently
utUize activated carbon, regeneration processes which were more efficient than thermal
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