Water filtration has many different benefits to offer. Filtering can remove any harmful pollutants that may be present and improve the taste of your drinking water. It can also reduce reliance on single-use plastic water bottles, helping protect the environment.
As there is
such a variety of uses for water filtration, there’s a wide range of different
methods available. Whether you want to reclaim wastewater in an effort toward
sustainability or merely make your water taste better, you’ll want to choose
your filter carefully. Not all filtration systems give the same results.
There are a lot of things to consider when looking for a water filtration system. Filtration methods vary in strengths, prices, convenience, and usage. Listed below are the pros and cons of the different techniques you may come across.
Activated carbon filters are some of the most common water filters you’ll find. Also called “charcoal filters,” these systems use a process called adsorption to extract impurities from water. Contaminants are naturally attracted to carbon, so they adhere to it as water passes through the filter.
Charcoal filtration is a popular choice for smaller home systems such as water pitchers and faucet filters. Activated carbon filters are typically inexpensive and easy to find, but you’ll have to replace them periodically. While carbon does remove chlorine, mercury, and bad tastes, it does not remove fluoride or dissolved solids.
taste of drinking water
carbon filters remove lead or other heavy metals
Need to be
remove all contaminants
alumina filters are far less common than their activated carbon counterparts,
but they use a similar process. As water passes through, some contaminants
cling to the alumina due to a natural chemical attraction. Where alumina and
carbon filters differ is the specific pollutants they attract: while carbon
attracts things like mercury and chlorine, alumina attracts material like
fluoride and arsenic.
believe that activated alumina adds aluminum to water, but this is a
misconception. Alumina is safe and does not add aluminum, but this does not
mean it doesn’t have its share of drawbacks. The process is not always
effective at different pH levels and disposal of alumina filters can be
removing dissolved solids and sulfates
can vary depending on pH levels
filtration doesn’t have to be high-tech. Ceramic filters take advantage of
earthenware’s porous surfaces to filter water simply and cost-effectively.
Millions of microscopic pores in the ceramics trap impurities but still allow
water to flow through.
will often coat the ceramic components in colloidal silver to increase their
effectiveness further. Due to their simplicity and the availability of their
elements, these filters are cheap and accessible. But while they are proven
effective at removing bacteria and protozoa, they are less effective against
smaller pathogens like viruses. They also run a higher risk of recontamination.
even to remote or disadvantaged communities
removing bacteria and protozoa
if cared for properly
effective at eliminating viruses
Need to be
can break easily
often see the term “distillation” in reference to alcoholic
beverages, but it’s also a method of purifying water. This process involves
boiling water into steam in one chamber and then condensing it back into a
liquid in a separate compartment. The heat kills microbes like bacteria, and
the vaporizing process leaves heavy metals and other harmful materials behind.
This method often takes the form of either solar distillation or multi-stage flash distillation, both of which are relatively large and complex systems. You can buy distilled water in bottles, but this increases single-use plastic consumption and may also be costly in the long run. Distillation also doesn’t remove contaminants that have a lower boiling point than water, and it can remove healthy minerals.
bacteria and other pathogens
remove all contaminants
Takes up a
lot of space
doesn’t rely on chemical processes to purify water like distillation and
activated alumina. Instead, it moves water through a
fibrous membrane, removing contaminants
physically. It works much like a mesh strainer, but the holes are microscopic,
so they let less through. Microfiltration membranes usually consist of durable
materials so that they can resist harsh elements for a long time.
membranes are more suited to industrial, large-scale use, so their prices run
comparatively high. But microfiltration systems are relatively
energy-efficient, which can help offset initial costs. While they are effective
at filtering out solids and bacteria, they do not remove all dissolved
metals and other solids
remove all dissolved contaminants
Not ideal for
Reverse osmosis is similar to microfiltration in that it uses physical filters. This method uses a series of different filters to remove impurities, but it doesn’t merely push water through them and into a reservoir. As the name implies, it uses pressure to reverse the natural process of osmosis, forcing water from a higher concentrated solution into a lower concentrated one.
osmosis requires you to use clean water in the process as the lower
concentrated solution, so it ends up wasting some water. It can also be an
expensive option, with high upfront costs and the need for regular maintenance.
But for this cost, reverse osmosis does remove almost all contaminants, and the
systems are usually convenient.
water treatment is not very common, but it is an option. This process uses UV
radiation to kill harmful microorganisms that may be in the water. It’s an
astoundingly effective method in this regard, destroying almost all bacteria
and other microbes.
systems may be expensive to buy and install, but they require little
maintenance and don’t use a lot of energy. While they are safe and
environmentally friendly, they do not remove contaminants like heavy metals or
other suspended solids. Ultraviolet light cannot thoroughly purify water on its
own, so you’d have to use it in tandem with another method.
effective at removing microbes
drinking water on its own
electricity to operate
filtration is a relatively new purification method. These filters expose water
to infrared light as it passes through, removing impurities like bacteria. Like
UV filters, infrared filtration systems do not remove all contaminants, so they
can’t produce pure drinking water on their own.
Infrared filters differ from UV filters in that they can soften water. Hard water is water that is high in calcium and magnesium, which can decrease the effectiveness of soaps or clog pipes over time. Infrared light removes these minerals, softening the water.
entirely purify water by itself
Costs can be
ionization is a complex process that purifies water by attempting to raise its
pH level. These systems use a process called electrolysis to separate water
into acidic and alkaline streams. The system then treats the alkaline stream,
which comes out of the faucet.
There are many proponents of alkaline water, but there is no medical evidence to suggest that it has many benefits over other forms of clean water. While alkaline water itself may not have any advantages outside of tasting better, many water ionizers contain useful filters that remove harmful contaminants. Ionizers are often expensive, which may make them less desirable than other, more affordable methods of purification.
have effective internal filters
the taste of drinking water
to offer benefits that are not medically proven
Choosing the Right Filtration Method
There’s a wide variety of filtration methods on the market, so it may be challenging to choose the right one for your own needs or desires. Water purification systems provide many advantages to your health and protect the environment, so you should take the decision seriously. No one kind of filter is superior to all the others, as the best choice depends on your specific situation.If money is an issue, you shouldn’t feel tempted to pay more than you are comfortable with for a high-tech filter. Ceramic and activated carbon filters can provide clean water for a small cost. If you have no objection to spending more money, you may consider paying for a more comprehensive system like using infrared treatment along with another method.
You should also consider your intended purpose for the filter. If you’re only interested in better-tasting water, a cheaper, smaller charcoal filter will be sufficient. If you’re looking for large-scale, thorough purification, look at more complicated systems like microfiltration or reverse osmosis.
No matter your end goal or budget, there is a filtration system available that will suit your needs.
Emily Folk is a freelance writer and blogger on conservation and sustainability. To see her latest posts, check out her blog, Conservation Folks, or follow her on Twitter, @emilysfolk.