Water purification

Water purification is the process of removing contaminants from a raw water source. The goal is to produce water for a specific purpose with a treatment profile designed to limit the inclusion of specific materials; most water is purified for human consumption (drinking water). Water purification may also be designed for a variety of other purposes and water purified to meet the requirements of medical, pharmacology, chemical and industrial applications. Methods include, but are not limited to: ultra violet light, filtration, water softening, reverse osmosis, ultrafiltration, molecular stripping, deionization, and carbon treatment.

Water purification may remove, particulate sand; suspended particles of organic materal; Parasites, Giardia; Cryptosporidium; bacteria; algae; virus; fungi; etc. Minerals calcium, silica, magnesium, etc., and Toxic metals lead; copper; chromium; etc. Some purification may be elective in its inclusion in the purification process; examples, smell (hydrogen sulfide remediation), taste (mineral extraction), and appearance (iron incapsulation).

Governments usually dictate the quality standards for drinking water water quality, these standards will require minimum / maximum setpointsof contaminants and the inclusion of control elements that produce potable drinking water. Quality standards in the United States require specific amounts of disinfectant (example, residual chlorine content) in the water after it leaves the WTP (Water Treatment Plant), at the end of the treatment process to reduce the risk of re-contamination while the water is in the distribution system.

Ground water (usually supplied as well water) is typically a more economical choice than surface water as a source for drinking water, as it is inherently pre-filtered, by the aquifer from which it is extracted. Over large areas of the world, aquifers are recharged as part of the hydrologic cycle, and their water is a renewable resource. In more arid regions, water from an aquifer will have a limited output and can take thousands of years to recharge. Surface water; (rivers, lakes, streams) is locally more abundant where subsurface formations do not function as aquifers; however, ground water is far more abundant than the more-visible surface water. Surface water is a typical raw water source used to make drinking water where it is abundant, ground water is unavailable or poor quality, however, it is much more exposed to human activity and its byproducts. As a water source it is carefully monitored for the presence of a variety of contaminants by the WTP operators.

It is not possible to tell whether water is safe to drink just by looking at it. Simple procedures such as boiling or the use of a household charcoal filter are not sufficient for treating all the possible contaminants that may be in water from an unknown source. Even natural spring water; considered safe for all practical purposes in the 1800s; and must now be tested before determining what kind of treatment is needed. Laboratory analysis will define the contaminants in the water sample, with both qualitative and quantitative measurements. Lab analysis, while expensive, it is the only way you will be able to obtain the bench mark information necessary for establishment of a purification process, methodology for purification.