EC238 Lecture Notes - Lecture 10: Biochemical Oxygen Demand, Nonpoint Source Pollution, Toxaphene
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Categorized by chemical and physical nature of the substance: 1) organic wastes (i. e. sewage from pulp mills or food-processing plants, pesticides, detergents and solvents, oil) 2) inorganic substances (i. e. toxic metals, salts, acids, nitrate and phosphorous compounds) High levels of dissolved oxygen (do) = high water quality. Biochemical oxygen demand (bod): do is used during decomposition of degradable pollutants found in water. Higher bod load on a body of water, the lower quality of that water. Persistent water pollutants remain for a long time (because they are non-degradable or take a long time to degrade) Md1 is too steep and md2 has too high of a y-cept, that pollution control policies would(cid:374)"t wo(cid:396)k he(cid:396)e; a full (cid:271)a(cid:374) would (cid:271)e (cid:374)eeded. Critical pollutants in great lakes: pcbs (insulating fluid transformers/hydraulics/lubricants), ddt (insecticides, now banned), aldrin and dieldrin (insecticides), toxaphene (insecticide, now banned), tcdd and tcdf (by-product of combustion/chlorine), mirex (pesticide/fire retardant),
