Topic 6 :Water Quality and Management

Dissolved in Water HHard water contains dissolved minerals like calcium, lime, fluoride, and magnesium that often form scaly deposits on faucets and tiles as water evaporates and leaves behind the minerals. TThese deposits can be removed by solvents like CLR SSoft water has less calcium and magnesium in it. Water softeners are added to make it soft OOxygen, CO 2, sediments, phosphate, nitrogen, sulfur, and some other chemicals can be found dissolved in water.

Bad stuff in water… TToxic substances are materials added to the environment that harms it or other organisms. (ex) PCB – used in making electronics DDT – used as pesticide CFC – used in fridgerants a/c, destroys O 3 SSulfur dioxide (SO 2 ) and nitrogen oxides (NO) are released into the air from burning fossil fuels. They come down in raindrops as acid rain. OOver time, the build up of these acids in the water and soil decrease the pH (level of acidity) affecting organisms’ lifecycles, reproduction, cells, developement

The pH scale Human blood 7.4 Normal rain 6

Bioindicators   The health of the environment can be evaluated by looking at bioindicator species sensitive to changes in the environment. (ex) insect larvae, northern leopard frog, salamanders, fish, clams, snails, algae   Changes to their development and lifecycles give us indication of problems, pollutants   Contaminants in the environment can make their way into the food chain and affect top predators like humans through bioaccumulation

Purifying Water   To make water potable (safe for drinking), it has to go through water treatment. See diagram on page 463 WATER INTAKE FROM RIVER LIME, ALUM, CHARCOAL ADDED TO WATER AT TREAMENT PLANT TO REMOVE DIRT AND SEDIMENTS. WATER PUMPED THROUGH SAND AND GRAVEL TO FILTER OUT FURTHER PARTICLES CHLORINE AND OZONE ADDED TO KILL ANY BACTERIA LEFT. FLUORIDE ADDED

Sewage   Sewage is the waste from homes, businesses, industries. Basically what goes down toilets and sinks and drains.   What happens to sewage? SEWAGE IS PUMPED TO SEWAGE TREATMENT PLANT SEWAGE IS FILTERED TO REMOVE LARGER PARTICLES. CHEMICALS ADDED TO KILL BACTERIA, REMOVE SMELL, AND SMALLER PARTICLES THE “CLEANED” WATER IS NOW CALLED EFFLUENT AND PUMPED BACK INTO THE RIVER

A gorgeous garden on Phi Phi island Thailand….but what was that smell????

Oh……

  In rural areas with no access to sewage treatment, sewage is collected in septic tanks for trucks to collect

New Sources of Water AAs fresh water supplies dwindle, we look to the sea for more water to desalinate GGiant distillation stations separates the salt from the water. WWater can also be put through reverse osmosis. Semipermeable membrane Pressure pushes water through membrane Purified water