Abstract: Surface accumulation of crystalline treating agents, such as pentachlorophenol, and water insoluble extracted wood resins, developed during solvent removal after pressure impregnation, and readily removed by contacting the so treated wood while still in a heated condition with liquid solvent thereby causing ebullient boiling of the solvent at the surface effecting a cleaning action and dissolution of the removed crystalline agent in the body of the solvent. If the solvent is contacted with the hot surface and removed immediately following cessation of ebullient boiling no additional post treatment is necessary to remove solvent from the surface of the wood. If desired a light (short duration) post steaming, however, may be employed without adverse effect, i.e., bringing more treating agent to the surface which would again permit crystallization of the agent at the surface.

Abstract: A method for producing clean surface treated wood by subjecting the wood, containing the treating agent and its carrier, to steaming under pressure thereby to cause the solvent in the atmosphere about the wood to condense on the wood surface during the steaming, thereafter reducing the pressure to about atmospheric pressure, removing the carrier vapors from association with the wood as they form, and continuing the steaming until the carrier is substantially removed from the wood.

Abstract: A method for removing antimicrobials such as pentachlorophenol from waste water by liquid-liquid extraction with a water immiscible organic liquid in a packed column; recovering the antimicrobial from the organic phase by distillation if desired; and, treating of the aqueous phase to remove residual antimicrobial and organic liquid. The process of the present invention recovers about 99 percent of the antimicrobial pentachlorophenol in the waste water producing a waste water containing less than 30 ppm pentachlorophenol and less than about 2 percent organic liquid, both of which may be removed by conventional carbon absorption or soil percolation to acceptable ecological levels for introduction into a stream or reuse as process water.