HSCI 20200 Lecture Notes - Lecture 5: Maximum Contaminant Level, Norman Borlaug, Flocculation
6 Sep 2016
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Document Summary
Essentials of environmental, occupational, and radiological health sciences (hsci 20200) Four main sources of pollution: industrial wastes. Containing heavy metals and organic chemicals in water. Biodegradable- a process of natural disposal and recycling. Bioaccumulation- chemicals persist, increases risk for being taken up by organisms. Organic pollutants: polychlorinated biphenyls (pcbs) chemicals that bio accumulate increase risk for bio magnification. Human health effects: rashes, liver damage, immune system, endocrine disruptors (toxins that interfere with endocrine system: domestic sewage. Primary treatment- (highly dependent on community factors) collect sludge into tanks. Tertiary treatment- methods to achieve chemical separation of phosphates and nitrates: stabilization ponds- require lots of land but are simple and cheap, activated sludge plants- require lots of power and, storm and urban runoff skilled workers. Large amounts of sediments and other pollutants are carried into water supply. Contaminants: sand, dirt, road salt, oil, grease, heavy metals. Storm water ponds- controlled place to store storm water: agricultural practices.
