Filtration - Pros and Cons
Filtration is the most effective type of water
treatment and purification currently available. Carbon and multimedia
filters build upon the treatment capabilities of reverse
osmosis and distillation. They retain all of the good filtration
qualities of these two systems while efficiently removing additional
water contaminants. They are able to rid water of the larger
compound materials, like salt, while selectively removing much
smaller and dangerous chemicals, like chlorine and pesticides,
that reverse osmosis and distillation systems cannot remove.
Because carbon and multimedia filters utilize both chemical
and physical filtration processes, they are able to selectively
remove a large number of drinking water contaminants. Water
filters can remove the small, but dangerous pesticide and herbicide
chemicals while allowing larger, trace minerals to safely pass
through the filter with the water. The retention of trace minerals
in water provides a much healthier source of drinking water.
The chemical adsorption
process, which carbon and multimedia filters use, is the only
filtration process that can selectively filter unwanted materials
Also, the slow filtration process of carbon and multimedia filters does not require costly energy sources like reverse osmosis and distillation systems. Because carbon and multimedia filtration systems do not require a heat or pressure source, they are fairly cost-effective. Carbon and multimedia water filters waste relatively little water in the filtration process.
Filtration, like reverse osmosis and distillation, is a fairly
slow process as it requires several stages of water purification.
Although the process is slow, once the water has been through the required stages, it is freer from contaminants than the water product of any other purification technique.
Besides the relatively slow process, there are a few other aspects to filtration that may make it less than ideal. Depending upon the type of filter used, water may have limited contact time with the filter media, resulting in only partial removal of drinking water contaminants. Also the type of filter media
may affect the number of contaminants that can pass through
the filtration process. Rapid filters and granular filters are
less effective than solid block carbon filters. Rapid filters
allow for only brief contact time with the filter media, limiting
the amount of contaminants that may be removed through the adsorption
process. Granular filters contain fairly large pores and allow
several contaminants to pass through the filter media. For the
most reliable and efficient filtration, solid block carbon or
multimedia filters should be used.