Removal of Phenolic Compounds from Wood Preserving Wastewaters

摘要

Laboratory and pilot-scale studies were undertaken to develop economically feasible technologies for the treatment of wastewaters from wood preserving operations. Of prime concern was the removal of phenol and its chlorinated derivatives, in particular, pentachlorophenol. Screening analysis of the wastewater indicated that pentachlorophenol was the only chlorinated derivative consistently present in concentrations of approximately 100 mg/l. Treatment technologies investigated for the treatment of these wastewaters included: (1) adsorption; (2) biological oxidation; (3) chemical oxidation; (4) coagulation; (5) extraction; and (6) pH adjustment. Each of the above, along or in combination, was capable of yielding a measurable reduction in the concentration of total phenols and pentachlorophenol in the untreated wastewater. Two technologies yielded consistently high levels of treatment: pH adjustment of the wastewater, followed by adsorption with bentonite clay and final polishing by the polymeric adsorbant, XAD-4; and pH adjustment of the wastewater, followed by extraction with a mixture of No. 2 fuel oil and a co-solvent such as still bottoms from amyl alcohol production.