Water can be defined to be a liquid that is clear, has no smell, colorless and is tasteless. This substance exists naturally and can be salty or non-salty. It is one of the most essential elements for both plant and animal life. It is also used for purposes as a solvent. As a result of its use, water gets filled with impurities that make it unsafe for the normal plant and animal use, likewise as a solvent.
Water treatment refers to a process of getting rid of impurities and pathogens from wastewater and the sewage. These impurities contaminate water, and they exist in a variety of forms as the physical, biological and even chemical impurities. Treating water enables sludge and the effluent to be discharged back into the environment without causing any hazard. Well treated water can retain its pure and natural state. Furthermore, with the fact that water is pure in its original state, is mixes with organic substances and other man-made chemicals and pollutants that make it harmful to plant and animal life.
There are various methods of treating wastewater to make it suitable for drinking by man and to be used by plants and other animals. The various methods include the following: settling, boiling, chemical disinfection which involves the use of iodine and chlorine tablets; works in large scales and I swimming pool, among other methods (Cheremisinoff, 2002). Water is normally treated in order to get rid of the impurities and other pollutants that render the water to be toxic to living things. Wastewater contains both dissolved and suspended impurities coming from industries, sewage, agricultural pollutants and nuclear wastes. The use of polluted water results in sickness and death.
There are generally three methods of treating wastewater or sewage; primary treatment, secondary treatment and the tertiary method. The secondary and the tertiary methods have some differences and subsequent similarities. In the first case, both are the methods of treating wastewater. The tertiary method is also known as the advanced or the final method of water treatment. Secondary treatment involves the degradation of the biological contents in the sewage. These contents arise from wastes due to food, soaps and detergents. The process makes use of oxygen and enables the bacteria and the protozoa to consume the biodegradable soluble organic impurities and also converts the less insoluble into what is called floc. This method of water treatment has more steps in it; the suspended growth treatment; trickle filtration, roughing filters, activation of the sludge, oxidation on the filter beds, biological aeration where de-nitrification is carried out and the secondary sedimentation where the biological floc is settled out and the sewage water and the suspended material produced (Cheremisinoff, 2002). While the tertiary treatment involves the final treatment in order to polish the effluent before it is discharged into the receiving environment. It involves stages as filtration, lagooning, removal of contents as the nutrients, nitrogen, phosphorus, carrying out disinfection by use of chlorine, removal of the odors and finally the sludge is treated and disposed. The treatment methods in this case include the aerobic and the anaerobic digestions and the composting among others.
The tertiary treatment refers to the final treatment only before disposal of the sludge while the secondary method of treatment refers to all the stages of wastewater treatment up to the disposal stage. Both methods make use of the oxygen and works to get rid of nutrients as the nitrogen before disposal.
Reclaimed water can be used in various ways though they are not recommended for other uses. The law forbids the use of this water and allows to be used in drip irrigation where the irrigation is done directly through the root system of the plant.
It is against the law to let the treated water be used for drinking, however, secondary treatment can totally treat the wastewater to an extend of being used for drinking. This is because the method is very effective in the elimination of the micro-organisms and the organic content in the wastewater. It furthermore treats the sludge before it is disposed. It almost resembles the natural method of treatment where micro-organisms are destroyed naturally in the environment (Qasim, 1999).
In conclusion, treated water can be used in many ways but it should be well treated in order not to affect the living things. The methods of treating wastewater are varied but they all attain one purpose. The water should have its necessary qualities to make it clean and pure.