PHENOL LEACHABILITY FROM PHENOLIC RESIN MATERIALS
Dennis J. O'Brien, Assistant Professor
John A. Olofsson, Jr., Assistant Professor
Department of Civil Engineering
University of New Hampshire
Durham, New Hampshire 03824
INTRODUCTION
Impending regulations under the Resource Conservation and Recovery Act (RCRA) of
1976 necessitate more careful handling of hazardous waste materials.  Materials heretofore
considered inert may be classified as hazardous because of their potential to leach toxic
compounds at disposal sites.  Since sanitary landfilling of solid industrial wastes is a common means of disposal, these regulations are directed at the identification of wastes which
would generate toxic compounds under conditions existing within landfills.  Control of this
phenomenon is important to protect groundwater quality.
Phenolic compounds are widely used in many industries including fiberglass production,
petroleum refining, steelmaking, the wood products industry, and synthetic resin manufacture.  Depending on the nature and strength of the waste, treatment processes for aqueous
phenolic wastes have included biochemical oxidation, adsorption, and chemical oxidation
with strong oxidants such as chlorine, chlorine dioxide, ozone, and hydrogen peroxide.
The purpose of this paper is to illustrate the generation of phenol from industrial waste
materials by leaching with water under conditions simulating those of a sanitary landfill.
The waste materials studied were phenol-formalde-hyde resin solid wastes obtained from a
fabrication plant utilizing these resins.  Phenol-formaldehyde resins are widely used
throughout industry because of their strength, durability, and electrical properties. Procedures similar to those used in this study could be used to evaluate the leachate from any
solid waste material.  In fact proposed regulations under the RCRA mandate such a test to
determine whether a material is to be classified as "hazardous".
PROPERTIES OF PHENOL
Chemistry
Table I lists the chemical structure and selected properties of phenol and related compounds. The related compounds are included since they pertain to the reactions of phenol
and its classification for regulatory purposes.  It can be seen from Table I that phenolic
compounds are solid or liquid at room temperature with relatively high boiling points.
Phenol itself is moderately soluble in water. The solubility of phenol is due to hydrogen
bonding between the hydroxyl group and water molecules. Other phenols, especially the
chlorophenols, have lower solubility in water which decreases as the degree of substitution
increases.
Another important property of phenol is its acidity.  Phenol is an acid which reacts with
water according to the reaction:
C6HsOH  ( > CtHsCT + H'1'
phenol phenoxide ion
The phenoxide ion is very soluble in water, much more so than phenol. Although
phenol is an acid it is an extremely weak one, with Ka = 1.1 x HT10. Therefore, under
practically all conditions in natural waters, ground waters, or landfill leachate where the pH
is usually in the range 5-8.5, phenol is almost totally unionized and little phenoxide ion is
present. Chemically then, the properties of phenol in aqueous solution are essentially
those of the phenol molecule itself.
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