Treatment of waste water Clean Water Act Sources …

1 CH. 21 (+ 22): Water PollutionTypes of Water pollutionSources of Water pollutionClean Water ActTreatment of waste waterPossible Test Questions:1. List and discuss 6 categories of Water Discuss how sewage is related to biological oxygendemand (BOD), dissolved oxygen, Discuss the problems associated with pesticide DDT as a specific example. (More in Ch 22)4. Why were PCBs thought to be a miracle chemical ?Why is this organic chemical an environmentalcurse .5. Contrast point source pollution and non-point sourcepollution, giving examples of Distinguish among primary, secondary, and tertiarytreatments for pollution : physical, chemical, biological changes inwater quality that adversely affect living :Infectious AgentsOxygen-Demanding WastesInorganic PollutantsOrganic ChemicalsSediment (Particulates)Thermal PollutionInfectious Agents: pathogenic organisms.

2 Water -bornediseases include typhoid, cholera, bacterial and amoebicdysentery, polio, infectious hepatitis, guinea worm andschistosomiasis. Due to lack of coliform bacteria (E. coli). Presume ifcoliform bacteria are present, infectious pathogens arealso Wastes: Oxygen dissolved in Water isindicator of Water quality. 6 ppm O2 or more supportsdesirable aquatic : Biochemical oxygen demand: measures theamount of dissolved oxygen consumed by aquaticmicroorganisms. Sewage, paper pulp, or food wastescan cause an Oxygen sag, where few fish and Eutrophication: rapid succession in a body ofwater because of an increase in biological productivity.(Oligotrophic lakes and rivers have clear Water and lowbiological productivity).Inorganic Pollutants: Heavy metals, like mercury, lead, tin,cadmium, selenium, and arsenic are caused by :Mercury poisoning from coal, incineration Causes:- damage to the nervous systemmetal retardationcerebral palsydevelopment delays- kidney disordersLead poisoning from incineration, pipes, solder (previously in shot, gasoline)Causes: - miscarriages- hearing loss- learning disabilitiesInorganic PollutantsNonmetallic Salts:Arsenic from mining or drainage of desert soilsCauses: - anemia- cancer- Chloride: SalinizationAcids:Sulfur and nitrogen compounds from : - pH changes which affect species- leaches aluminumOrganic Pollutants: Dioxin, PCB, DDT (Chlorinated)Dioxin: stable.

3 Slow to degradeGenerated from:Burning wood, coal, oil, householdtrash, and chlorine bleaching of pulp and paperAccumulates in fat of animals biomagnificationCauses:cancerweakened immune responseOrganic Pollutants:PCBs: non-flammable; not dissolved in Water ; high boilingpoints; does not conduct electricity well. So used fortransformers and than one billion pounds of PCBs have been in fat of animals biomagnificationCauses:cancerhormonal and reproductive disruptionsdecrease cognitive abilities (dopamine)Organic Pollutants:DDT: insecticide; stable and slow to Muller won the Nobel Prize in 1948 fordeveloping : Controlled spread of malaria;Provided crop protectionProblems with DDT: DDT is not metabolized very rapidlyby animals; instead, it is deposited and stored in thefatty tissues biomagnificationProblems with DDT: stable and slow to degrade - Toxic to Fish - Increased mortality in birds: calcium decreased in egg shells - Estrogen mimic in Vertebrates: feminizes males - lowersperm count.

4 Alters behavior - Human Healthdecreased mental functionmale infertilitycancerProblems with DDT and other pesticides:Unintentional Pathways:Effects on people:Problems: DDT (and other pesticides)Evolution of ResistanceNon-target Species and creation ofnew pestsSediment: Erosion and lakesobstructs shipping channelsclogs hydroelectric turbinespurification more costlyThermal pollution : an increase in temperatureCan cause:thermal shockparasites and diseasegreater vulnerability to toxic pollutantsMajor categories of Water pollutantsCategoryExamplesSourcesA. Causes health problems1. Infectious agentsBacteria, viruses, parasitesHuman and animal excreta2. Organic chemicalsPesticides, plastics, oil, gas,detergentsIndustrial, household, and farm use3. Inorganic chemicalsAcids, caustics, salts, metalsIndustrial effluents, householdcleansers, surface Radioactive materialsUranium, thorium, cesium,iodine, radonMining/processing ores, power plants,weapons, natural sourcesB.

5 Causes ecosystem disruption1. SedimentSoil, siltLand erosion2. O2-demanding wastesAnimal manure and plantresiduesSewage, agricultural runoff, papermills, food processing3. ThermalHeatPower plants, industrial coolingSpecific Sources of Ground Water pollution :(rate of breakdown is extremely slow in ground Water ) Industrial waste into aquifer recharge zone Surface runoff into abandoned wells Industry,agriculture, home Leaking underground storage tanks of gas stations Leaking septic tank into recharge area. Injection wells for secondary Source: discharge ofpollutants from single , power plants, sewagetreatment plants, oil Source: Sources of waterpollution that are scattered ordiffuse, not having a fields, golf courses,lawns, cities, roads,clearcut forests, minesWater pollution Control: Reduce the Sources of waterpollutionMaximum Concentration LevelsWater pollution Control: Agriculture is the biggest sourceof Water pollutionLegislation enacted to improve our Water : Clean Water Act: to restore and maintain the chemical,physical, and biological integrity of the nation s waters.

6 (1972/77/81/87)greatly decreased the amount of point source s, DDT, and Dioxin are no longer allowed aswaste products into Program: remediation of toxic waste sitescreated in 1980 Drinking Water Act: regulates Water quality incommercial and municipal systems. (1974)Improved Water quality has been one of the biggest successstories of the environmental Water quality:Chesapeake Bay America slargest estuary. reducing nutrient loading banning phosphate detergents restoring seagrass and wetlands. upgrading wastewater treatmentplantsMunicipal Sewage treatmentPrimary Treatment : physical separation of solidsSecondary Treatment : Aeration tank: biodegradationTertiary Treatment : remove phosphates/nitrates lagoon/marsh or trickling : use of organisms to remove Water pollutantsDomestic sewage Treatment : Septic tanks and drain fields.