Phenol and chlorinated phenols are toxic compounds found in many treated wood products such as fence posts and railroad ties, hence soils near such treatment facilities or near old railroad yards can be quite contaminated. This study investigated the results of using sodium bentonite clay modified with dimethyl di(hydrogenated tallow) ammonium chloride mixed with Type I portland cement to immobilize a series of phenols (phenol, 2,4,6-trichlorophenol, and pentachlorophenol) from a sandy Shawano B horizon (typic Udipsamment) soil.

The test soil was mixed with the various phenols at a contaminant concentration of 1000 mg/kg. An admixture of contaminated soil and modified clay (0 to 10% w/w organoclay) was prepared. Final solidification was done by adding cement at concentrations of 16 to 39% w/w. Toxicity characteristic leaching procedure (TCLP) and unconfined compressive strength determinations were made. The results of these tests indicate potential for using these organoclay admixtures for treating soils contaminated with various chlorinated phenols.