Potable Water Concept The purification is a process which is used to convert water to drinking water. The purification is done in natural springs and groundwater.
It's called drinking water to fresh water after being subjected to a purification process becomes drinking water, thus being ready for human consumption due to the balanced value that printed its minerals.
Characteristics of Potable Water It is called potable water or drinkable water, water that can be consumed without restriction because, through a process of purification, there is no health risk.
The European Union sets a maximum and minimum values for mineral content, different ions such as chlorides, nitrates, nitrites, ammonium, calcium, magnesium, phosphate, arsenic, among others. The water pH should be between 6.5 and 8.5.
In areas with intensive agricultural use it is often very difficult to find wells whose water meets the requirements of the standards. The reason of that problem is mostly the massive use of mineral fertilizers. That also threatens the drinking water supply. The causes of non-potable water are: Bacteria, viruses. Minerals (in the form of particles or dissolved). Toxic products, deposits or particles in suspension.
The steps for the potabilization process are: Sedimentation Coagulation. Softening. Elimination of iron and manganese. Elimination of odors and smell. filtration Aeration. Corrosion control. Evaporation disinfection
Sedimentation: Is the settlement of solid particles in water caused by gravity. There are 2 types of sedimentation: Simple or secondary. The simple is used for heavy solid particles and the secondary is used to remove those particles that are not deposited even with prolonged standing.
Filtration: Usually is used after the sedimentation, this process is used for more clarification. The most common process of filtration is made with a sandy bed of about 100 by 50 meters and 30 centimeters deep, and then some inoffensive bacteria act to eliminate the organic matter that stands in the water. The filters most useful in rural areas are those built with gravel and sand.
Aeration: It’s performed by dropping the water into a cascade to increment the proportion of oxygen in the water and the carbon dioxide is reduce in a 60% and it improves the purification with aerobic bacteria
Physical Methods a) Ebullition: It´s used to eliminate pathogenic microorganisms commonly found in water like: bacteria, cysts and eggs. b) UV Rays: It´s job is very limited because it is needed an especial equipment that need electric energy.
a) Silver: It´s very useful, doesn´t give taste and smell, Its effectiveness decreases when it´s in presence with other substances like chlorides b) Chlorine: It´s the most important element for the disinfection of water, eliminates all the bacteria in four minutes and also does things like: -Eliminate odors and flavors -Discolor -To help prevent the formation of algae. -Help to remove iron and manganese -Coagulation of organic matter.
Water Purification in Rural Areas
The water treatments for itÂ´s disinfection and make it usable for the human consume, occupy an important place inside de actual development of the science. Rural zones with insufficient hygienic resources,, energetic, cultural and economics result the more affected regions by the consumption of contaminated water, thatÂ´s why is essential to choose other water treatments that may guarantee the obtainment of good results for health with the minimum investment possible.
In the selection of this treatments, it is needed to take in count different aspects, like the level of risk in the health of the population, the energetic consumption, costs and efficience, between others.
The more universal an antique method for the disinfection of water is the boiling, that reach the elimination of pathogen elements that are transmitted by the water. But it is not a good option because it requires big quantities of fuel and an increase in the atmospheric contamination.
Inside the chemical methods, the treatment with chlorine is the more used. It is very effective for the elimination of pathogen elements and oxide the organic material that is presented in the water. By other way it requires an specific dosage, so it´s necessary a certified technique.
Water filtration it´s used since XIX century for eliminate the turbidity, cysts, and protozoan’s, but it is not effective to suppress the bacteria or viruses.
The usage of UV it´s secure and doesn´t presents risks of manipulation, the treated water doesn’t changes and can be taken. But this requires electric energy for the lamps.
For the present application it has been considered preferably the places that use water from wells or rivers for the human consumption and that stored it in little tanks or in recipes inside the house, situations that in general doesn´t exists water pumps that maintain a constant flow.
For the reasons that we already mentioned the ultraviolet light treatment method was selected, with the purpose of purifying water UV lamps for germicidal use are designed to generate radiation in the area, which damages the nucleic acids of microorganisms and protozoa, which inhibits the reproduction of organisms.
The results obtained by applying ultraviolet light at purifying water have worked as expected, and also used as solar energy source.