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TOXICITY REDUCTION THROUGH CHEMICAL AND BIOLOGICAL MODIFICATION OF SPENT PULP BLEACHING LIQUORS
Citation:
Dence, C., C. Wang, AND P. Durkin. TOXICITY REDUCTION THROUGH CHEMICAL AND BIOLOGICAL MODIFICATION OF SPENT PULP BLEACHING LIQUORS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-80/039.
Description:
Chlorophenols similar to or identical with those detected in spent chlorination and caustic extraction liquors were synthesized and tested over a range of concentrations to determine their effect on the growth of several fungi, an alga (Chlorella pyrenoidosa) and duckweed (Lemna perpusilla) and on the survival of Daphniamagna. Biological treatment of the chlorophenols consisted of the application of pure cultures of three different fungi and a mixed microbial population for periods ranging up to 15 days. Degradation varied widely among the various phenols and for the same phenol treated with different fungi. Spent chlorination and caustic extraction liquors were subjected to a variety of chemical treatments and the resulting effects on acute toxicity determined. Treatment with elemental chlorine, hypochlorous acid, hypochlorite, ozone and hydrogen peroxide produced increases in the toxicity of the spent liquor. Biological treatment of spent chlorination and caustic extraction liquors involved the application of a fungus (Candida utilis), an unidentified bacterium, and a mixed microbial population, together with supplemental carbon sources. Toxicity reduction through modification of conventional chlorination and caustic extraction bleaching stages was also evaluated.