RNR chapter 20 review

any chemical biological or physical change in water quality that harms living organisms or make water unsuitable for desired uses

• point sources- when water pollution come from a single source
• nonpoint when it comes from larger or dispersed source

• Infiectious agents (bacteria viruses parasites)
• Oxygen demanding wastes (biodegradable animal wastes and plant debris)
• Plant nutrients (nitrates )
• fOrganic chemicals (oli gasoline plastics pestocides)
• Inorganic chemicals (acids bases salts metal compounds)
• sediments (soil silt)
• Heavy metals (lead mercury arsenic)
• Thermal (heat)

• Typhiod fever from bacteria
• Cholera, Bacterial dysentery, Entrites, infectious hepatis (type B) from Viruses
• Amoebic dysentery from Parsitic protozoa
• Schistosomisis from parsitic worms

• chemical methods are used to determine the presence and concentrations of specific organic chemicals in polluted water
• biological methods is using indicator species by taking plants from the pollutied system and studying them or observing bottom dwelling species

in a flowing stream the breakdown of biodegradable waist by bactiera depletes dissolved oxygen and creates an oxygen sag curve, this reduces or eliminates population of organisism with high oxygen requirments untill the stream is clensed of oxygen demading waists

• in developed countries lawes require industries to reduce or eliminate their point source discharge of harmful chemicals into surface waters
• in developing countries it is a growing problem most of the rivers that are heavily polluted run through developing countires who cant afford to build waist treatment plans most of these countreis discharge 80 to 90% of their untreated sewer discharge goes directly into the river

the hindu cermonies of buring courps and throwing them into the river to insure their soul a trip to heaven pollutes the air and the river, especially if the corpes is not burned compleatly when it decomposes it suckes up oxygen in the river. they also drink and bathe in the river as part of their cermoines

• lakes often contain stratified layers that undergo litterl vertical mixing
• they have little or no flow so flusing can take 1 to 100 years compaired to seven days and weeks for streams

• Eutrophication is the name given to the naturla nutrients enrichment of a shallow lake, estuary or slow moving stream mostly from runoff of plant nutrients such as nitrates and phosphates from surround land
• Cultural etrophacation is greatly acceleartated input of plant nutrients caused by human activietes to a lake (farmland, animal feedlots etc)
• ways to reduce
• use advance waist trement to remove nitrate and phosphtes before waiste water enters the lake
• clean up lake
• stop excessive inputs of plant nutrients and the lake will recover on its own

• were vulnerable to pollution from point and nonopoint sources they surffered from server cultural eutrophication huge fish kills, and contamination from bacteira and a viratiey of toxic industral waistes
• spent 20 billion, decreased algal blooms, increased dissovled oxygen levelts and theseimprovements occured because of new or upgraged sweage tremeent plants better treatmetns of industral waistes and bans on use of detergents household cleanters and water condictionars that contain phosphates- all issued because of bottom-up citizen pressure

when groundwater becomes contiamitated it cant cleanse degradable waist as quickly as flwoing surface water it flows too slow and contaminates are not diluted and dispersed effecitivly and it usualyl has much lower concentatiosn of dissolved oxygen (which helps to decompose many contaminates( there is also smaller populations of decomposing bacteria and usually cold tempatures so slows down chemical reaction to waistes

• arsenic is toxic its like to cause thousands of premature deaths from cancer of skin, bladder ,and lung
• transforming common mineral similar to rust into powder of tiny nanocrystals and using it to purify drinking water could greatly reduce the theat of arsenic and it would cause a few cents a day

US requires the EPA to establish nationial drinking water standeards

plastic water bottles and green hosue gasses and other air pollutants are emitted by the fossil fueles burned to make and deliever the bottles of water

because about 40% of the world's populatioin lives on or near the coast, in deeper waters the oceans can dilute, disperse and degrade large amounts of raw sewage and otehr types of degradable pollutians

• runoffs of sewage and agricultural wastes into coastal waters that introduce large quanaties of nitrate.
• harmeful because at least 200 oxygen depleated zones form in costal waters around the world these are called dead zones no or few fish

dead zones

• for mairing life to recover form oil spills it takes 3 years for ssalt marshes 10 years it is slick ans washes on beaches and have major impacts on coastal residents
• ways to prevent and reduce pollution is reduce production from land and air from streams emptying into these waters

First, primary sewage treatment, a physical process, uses screens and tanks to remove large floating objects, rocks, and sand. Next, secondary treatment, a biological process, uses bacterial to breakdown biodegradable materials, but does not kill pathogens.

Finally, chlorination,ozone, or UV is used to kill pathogens and some viruses. A major problem is inadequate secondary treatment facilities in numerous cities and untreated storm water runoff systems, which allows pollutants to be discharged into coastal waters, lakes, and streams.

compositing toilet system conberts nutrient rich human fecal matter into a soil-like humus that can be used as fertilizer supplement. about once a yar venders collect the humus and sell it as soil conditioner this process returnes plant nutrients in human waist in the soil and thus minics the naturla chemical cycling, also reducceds the need for comercial inoraganic fertilizers

• fertilize garden and yard plants with manure or compost instead of commerical inorganic fertilizer
• minimize use of petsicides especially near bodies of water
• prefent yard wastes from entering storm drains
• do not use water freshners in toilets
• do not flush unwanted meds down the toiet
• do not pour pesticides paints solvents oil antifreeze or otehr products containing harmful chemicals down the drain or on the ground