Science-Fresh Water

Safe drinking water is a necessity for human survival and everyday activities (“Ground Water and Drinking Water”, 2006). Because naturally, all water in the world contains some impurities with respect to its supply and processes it undergone before going to its final destination. For instance, some impurities originated from additional man-made chemicals, erosion from natural rock formations, and the filter destinations that the raw water undergone (EPA Drinking Water and Health, 1999).

The sources of water vary from place to place. In urban areas, the water that most people use comes from surface water sources like lakes, rivers, watershed, and reservoirs. On the other hand, people in rural areas utilized water generated through pumping it to the underground soil, called aquifers which are natural underground water reservoirs.(CRC, 2003)

Then, before utilizing the water, it has to undergo some treatment and purification processes in order to check its safety, palatability, usability, and compliance to the standards set by the authority (EPA Drinking Water and Health, 1999). Upon its storage, it has to be filtered, conditioned, and disinfected to diminish the presence of impurities and bacteria in the water. These processes are undertaken in an authorized water treatment plant. Then, the water is now to be distributed through various point consumers such as residential, commercial, and industrial (“Asia Brewery,” 2004).

On a greater extent, the water of the world faces some issues more especially on supply and conservation. Just like in African nation, there is crisis in water supply that causes high death rate. Also, in cities like in Metro Manila, Philippines, the crisis in water supply can be related to insufficient water storage in most watersheds and reservoirs.

This study will utilize library and online research for better illustration and interpretation of the research topic.  However, an actual visit to freshwater treatment plant and interview to authorized plant personnel and operators are needed for actual field experience and appreciation to fully supplement the concepts read in the literatures like books and magazines.

Drinking water can come from numerous natural sources. Freshwater, although accounting for a very small percentage of the Earth’s total water supply, is quite plentiful and can be found in nature in various forms. Freshwater which can also utilized as drinking water can be found on surface waters, groundwater, glacial ice, and underground springs. These sources are those usually tapped for raw water to be processed into a community’s drinking water. The main problem is not the availability of water but the processing it requires by which it can attain the standards needed to be safely drank.(CRC, 2003)

The main standard in defining whether water from a source can be safe to drink is by measuring the microorganisms present in the water. Coliform content, heterotrophic plate count, and turbidity are dome measurements that indicate the amount of bacteria present in a given water sample. Other, more specific tests are also in place to measure microorganisms like E.coli, Giardia liamblia and Cryptosporidium. (USEPA, 2006)These microorganisms usually result in diarrhea and other gastro intestinal diseases when found in sufficient quantity in drinking water.

Another aspect that is monitored in drinking water safety is the presence of contaminants. These come in the form of chemicals/ elements that are harmful to the human body when imbibed in certain amounts. These includes heavy metals like lead, which causes lead poisoning, radioactive elements and isotopes, and body poisons like cyanide and arsenic, which in sufficient amounts, causes death.(USEPA, 2006)

Water comprises most of the human body and is essential in most of our processes. Therefore a steady supply is needed everyday in order to ensure a person’s health. Water also contains minerals, which in trace amounts are essential to body processes. Water is needed in metabolism, muscle activity, digestion, almost in every aspect of the human body. (CRC, 2003)

In The city of Chicago, Illinois, water that supplies the whole city is derived from Lake Michigan. Water from the lakes enters the intake at about 20-30 feet. It then passes through a series of filters that screen out large debris. The water is lifted upwards by means of pumps and then pre-treated with chlorine. Water then enters the flocculation basin, where a rapid mix tank ensures that the flocculation process is carried out. These utilize the electrical charge of unwanted compounds to separate them from the water. Alum is added to the water for the flocculation process. The rapid-mix tanks make the smaller particles in the water come together into larger clumps called flocs. The plant utilizes aluminum as a coagulant, using it to bind sediments together. Water that is coming from the flocculation chamber flows towards the sedimentation bed, where it sits for 4 to 7 hours. This is to allow the floc sufficient time to settle.  After settling, the water passes through a more thorough filtration system. This system consists of layers of sand and gravel.   Afterwards, the water settles in the clearwell, where chemicals like fluoride and phosphates are added.

The water then flows towards Chicago’s distribution system. This distribution system makes use of artificial pressure in order to provide water to households in the city. In the suburbs, water towers are sometimes utilized in order to harness gravity as a source of force for the water flow.

In the village of Oaklawn in Illinois, water is supplied by the municipality. Three wells supply water to the city, one of which is located at Oaklawn itself. Chemicals added to the water include chlorine as an anti-microbial, fluoride, for dental health, and polyphosphates, in order to minimize the corrosion of lead pipes.
The City of Chicago can provide us a view of what a normal municipal water treatment system looks like in the United States. However, in other, less developed countries, the treatment of water by the government for public use is sadly lacking. This inability of the public offices to provide safe drinking water to its constituents s results in an increase in home water treatment gadgets in both rural and urban areas. These devices usually consisted of tap water being passed through a filter composed of several layers of different materials. The lack of drinkable water from the tap also increases the use of bottled water.

In the production of distilled water on the other hand, water is subject to a commercial distillation system which utilizes vapor compression. Vapor compression is a much more cost efficient method of distillation since it uses the heat from the boiling waters vapor to add more heat to the system, all this while the vapor condenses.(AquaTechnology, 2007) After that, ozonation is again employed to make sure no bacteria are present in the water. Distillation makes sure 99.9% of the water is pure, however, the process of removing impurities at the molecular level also removes minerals present in the water that are vital to the body’s processes.

In the case of municipal water distribution systems, chlorine is added in the facility, in some cases into the pipes themselves. Chlorine is used as an anti microbial chemical to ensure that whatever microbial contamination that the water encounters during its distribution is easily countered. In the case of bottled water, water is sealed into disinfected PET bottles and then sealed with a plastic cap cover. (CRC, 2003)

The private sector has also utilized various means by which to purify water. These range from simple filters that are placed directly on the faucet to complex machinery that undergo those steps of commercial purification but at a smaller scale.  These machines provide a combination of the various processes that purify after and make it safe to drink. Portable distillers are now available, most with built in filtration systems.

Aside from the other basic processes, other methods are used by water treatment plants to treat drinking water. Ultraviolet radiation is used in place of ozonation to kill off bacteria and other microorganisms still present. Lime is added in some areas where water is acidic, in order to bring it to the desired pH level of around 7. In some plants, extensive pre-treatment is also undergone. These include the addition of sodium carbonate in order to soften up hard water, and preliminary filtration for surface waters. The most commonly used disinfectant is chlorine, and its derivatives. Chlorine acts as an oxidant. It kills ff most microorganisms. However, chlorine used in treatment can sometimes reach its gaseous form, which is poisonous to humans. Chlorine and its derivatives is also a carcinogen in sufficient quantities, making it a health hazard to consumers.

In special cases, additional treatment to drinking water can also be implemented. The addition of fluoride in some areas is used as a precaution to tooth decay. In cases where ions in the water dissolve the lead in pipes, Plumbosolvency precautions are undertaken. This involves increasing the pH as well as adding phosphate ions. Some areas where radioactive isotopes are present in the area around the water source use ion exchange to eliminate these ions.

Other methods include boiling, mostly in developing countries. Filters containing carbon in the form of charcoal, as well as silver ions also act in making water safe for drinking by removing microorganisms. Reverse osmosis, involving the use of a semi permeable membrane to remove impurities is also a commercial water purification technique.

In the developing countries, water is available in large quantities and is generally safe to drink. These are the exception, instead od the rule in numerous countries ariuynd the world. Countries in Africa and in the Indian subcontinent are currently in a crisis to provide safe drinking water to their people. In Africa, drought is a prevalent occurrence, and the numerous wars have turned what available water there is into deadly weapons, poisoned so that the other side has no use for them. In India, their Holy River Ganges, the primary source of water for millions of inhabitants, is fraught with pollution ranging from human fecal waste to industrial runoff.

Most of the countries in the world still obtain their drinking water naturally, with no or minimal treatment. This is due to the cost of treatment, lack of facilities and education. Many are unaware that the water they drink everyday contains microorganisms and contaminants that are harmful to their body.

In most of these poor or developing countries, the rivers and water systems by which they obtain their drinking water is polluted. And since water treatment is at a minimum, these countries still experience a high rate of diarrhea, gastro intestinal problems and dehydration. T them, water, in any form is a great resource while to those of us living in developed countries, water is often taken for granted, wasted and disregarded.

Water is necessary to life. However, drinking water for human purposes is limited in quantity. Most of the freshwater in the world are frozen in glaciers, or deep underground. The increase in human population, the resulting pollution has further taxes our ability to provide safe drinking water. Most people in developing countries drink unsafe water fraught with microorganisms and contaminants simply because they have no means of purifying it. The pollution of our streams and ground water has eliminated a free drinking water supply, making water a rising market commodity. Like all natural resources, water in the form we can safely use is finite. The challenge is in coming up with a cheap, cost effective method by which safe drinking water can be made available to everyone. And even then, water, as with life, should not be wasted; it must be conserved and secured in order to ensure the health and survival of our species.

 

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