Pentachlorophenol (PCP) has been used as a biocide and preservative for wood power poles and crossarms. If disposed in landfills, the natural capacity of landfills to transform hazardous constituents to less hazardous or inert substances may also apply to such PCP-treated materials. The principal reaction of interest in the anaerobic environment of a landfill is reductive dechlorination.
The fate and transformation of PCP-treated wood was investigated in simulated landfill bioreactors operated under single pass leaching and leachate recirculation. The wood samples consisted of 2% of the total mass by weight loaded into the bioreactors. The PCP leaching potential was examined at varying pH conditions with TCLP and Soxhlet extractions. Adsorption of PCP to the synthetic solid waste was used to determine its role in immobilizing leachate PCP. Routine indicator parameters were used to describe the acidogenic and methanogenic phases of landfill stabilization. Leached PCP was transformed without inhibitory effects on landfill stabilization, thereby affirming the acceptability of such a codisposal practice.