Distillation - Pros and Cons
Aside from desalinating water, the distillation
process will reliably remove bacteria and viruses and dangerous
heavy metals like lead, arsenic, and mercury. Distillation is
ideal for recipients of non-municipally treated water, due to
the particular challenges and heavy contamination of raw, untreated
water. For this reason, distillation is often used as the preferred
method of water treatment in developing nations that must work
with heavily contaminated, untreated drinking water. Distillation
is extremely effective at the removal of bacteria and often
used in areas at high risk of waterborne diseases. Distillation
also removes soluble minerals like calcium, magnesium, and phosphorous
that may harden water and increase the occurrence of scaling.
The distillation process contains several elements that make
it undesirable for purifying drinking water. First of all, while
the vaporization process will strip water of salt, metals, and
bacteria, the boiling point of most synthetic chemicals, including
pesticides, herbicides, and chlorine solutions is lower than
the boiling point of water. Synthetic chemicals are the major
contaminants remaining after municipal treatment. Distillation
does not remove these harmful chemicals.
Also, distillation is a very slow process and requires a heated energy source. Though experiments in the use of solar power have been attempted, this form of energy is only able to treat small quantities of water and difficult to maintain at a constant temperature (Holland et al, 1999). The inefficiency of solar power requires the use of more costly energy forms. Also, because this process must be repeated several times to ensure significant water purity, it could take several hours to provide one gallon of cleansed water. Generally, distillation requires five gallons of tap water to generate one gallon of purified water.
Finally, distillation, like reverse osmosis, strips water of natural trace elements. When these elements are removed from water, the hydrogen composition becomes greater in proportion, making the water very acidic. Several studies have proven that drinking distilled water, stripped of minerals, can actually be harmful to the body system (Rona, 1995). Long-term consumption of such de-mineralized water can result in mineral deficiencies in the body. Though the removal of trace minerals creates water that is ideal for use in photo or print shops, it creates tasteless and even unhealthy drinking water.