Water+Pollution

WATER POLLUTION Dissolved Oxygen in Water

BOD stands for the biological oxygen demand. WHY is this important??? Because living all living organisms demand oxygen to survive, including aquamarine organisms.This is measured in parts per million or PPM. Fish at least needs 3 ppm. However water with 5 ppm or above is regarded as polluted.

Oxygen in water is also important for the decomposition for organims!!! Aerobic respiration is relatively CLEAN and PLESENT, Anerobic respiration is FOUL and SMELL. E.g. MARSH GAS, "ROTTEN EGGS" GAS.

The solubility of Oxygen in water changes according to the temperature. You would imagine that as temperature increases the solubility of oxygen would also increase. But infact as temperature increases the activity of organisms also increase, thus the usage of oxygen also increases.



 Eutrophication


 * FARMING uses tonnes and tonnes of fertilizers, and they contain nitrates~
 * Too much Nitrate causes excessive growth in plants, it is BAD
 * When TOO many organisms GROW in the SAME place, IT USES LOTS OF OXYGEN
 * And the water becomes inhabitable. due to LOW levels of oxygen.

THERMAL POLLUTION


 * Heat causes the solubility of oxygen to decrease in WATER
 * THIS IS NOT GOOD, this causes two negative effects on life
 * DECREASE in solubility means that there is less oxygen in the water.
 * INCREASE in heat energy means organisms are more active, therefore more respiration and use of Oxygen.
 * IT causes the water to become inhabitable.