________________
d) Chlamydia trachomatic causes Trachoma. viii) Parasitic worms: Cause round worm, hook worm infection. ix) Virus: Hepatitis A & E viruses spread though water. It affects
nervous & reproductive system. Causes inflammation of liver, loss
of appetite, nausea etc x) pH Value: This is a measure of alkalinity. It is very important to
keep the pH water at a value which favors the growth of bacteria.
The recommended value is 6 to 8. ph 8 means alkaline water. xi) Oil and Grease: If these are not removed from the waste water
before discharge, it can interfere with biological life below the
surface water. It creates layers of floating matter and films of oil. xii) Chemical Oxygen Demand: COD is the quantity of oxygen
needed to oxidize chemicals. It is a measure of depletion factor for
both waste-water and natural water. xiii) Biological Oxygen Demand: BOD This is the most widely used
parameter of organic pollution of both waste and natural water. It is the quantity of oxygen required by bacteria to oxidize organic matter present in water and is the main factor in deoxygenation. Heat, organic waste, suspended minerals and toxic chemicals
reduce the solubility of oxygen. Unpolluted natural waters are generally saturated with oxygen. That is why the measure of dissolved oxygen is one of the main factors in stating the pollution load for any type of water. Water without oxygen is 'dead' and may be turbid. Water has natural tendency to reaerate itself. It involves the measurement of dissolved Oxygen used for oxidation of organic matter over a given period. Potassium chromate (K,Cr,0) is commonly used as oxidizing agent. c) Treatment of water for Domestic use:It is obvious that drinking water should be either made free from above contaminants or should be reduced to permissible safe levels. Water can be completely purified by distillation and deionization. However, many organisms and creatures, which may otherwise be useful to human beings, cannot survive in de-ionized and distilled water. The treatment of effluent water is generally done by following method:
Jain Education International
For Private & Personal Use Only
www.jainelibrary.org
