Pollution of water

BOD (Biological oxygen demand) is the measure of oxygen that is needed to break down organic material in water. So the microorganisms need this biological oxygen demand to decompose organic waste. It depends from the river if the BOD is high or low. If in the water are a lot of organic waste then more oxygen is needed from the bacteria’s to do the decomposing process. The exceeding value of BOD would increase the amount of oxygen and in that level that many species would die expect of the microorganisms. The normal amount of BOD in sewage is around 250pmm. Nitrite and nitrate are inorganic compounds which are contributing to a higher BOD. Nitrite and nitrate can be natural or man made and both of them are helping to contaminate the water. Nitrates are helping the plant process of the algae in a fast way and when they grow fast they also die very fast so there will be a lot of organic waste and the demand for oxygen will increase and when we have a higher amount of oxygen many species that are not used to this amount of oxygen will eventually die. To avoid such situation people should not throw garbage in water because in that garbage might be a high amount of organic materials and when you throw that in the river, the river will normally produce a lot of oxygen for the bacteria’s to decompose those materials.