Disposal of sewage water is a major problem in developing countries. On one hand, industrialization is opening new doors of modernization and also providing jobs. On the other hand, this industrialization is making the environment too much polluted.
Lack of adequate sanitation in large areas leads to spread of disease causing bacteria and virus into other sources of water. Apart from this, pharmaceutical and chemical products are also not disposed off in a proper manner. All these increase the chemical load of sewage water. Oil spillages, dumping waste products into oceans and river water, etc. largely contribute to the contamination of water. Some of these pollutants such as aluminium, plastic and Styrofoam take really long time to degrade.
Water treatment process is very important as it makes the water re-useable. Water treatment plants carry out several processes to treat contaminated water to make it fit for industrial and domestic consumption.
Water undergoes a pre-treatment process as well. It includes:
Pumping and Containment
Screening
Storage
Pre-conditioning
Pre-chlorination
After pre-treatment, the water is further treated in the water treatment plant.
pH Adjustment- pH level of neutral water is 7. pH adjustment is done to neutralize too much acidic or alkaline nature of water.
Flocculation- used to remove turbidity from water
Sedimentation- the floc that precipitates from the water during the flocculation process is separated.
Filtration- final stage of removal of dirt from water.
Removal of Chemical Impurities and Ions- hazardous chemicals such as lead, arsenic and nitrite are removed
Disinfection- Chemicals like chlorine are added the water to kill disease causing virus and bacteria.
Water softening plant softens hard water and makes it fit for domestic and commercial purposes. Hard water does not cause any disease but it is not fit for using as well. For example, if you wash your clothes in hard water, lather will not be much. Hence, hard water should be passed through various processes in a water softening plant.