Factors to Consider Before Purchasing Sand Water Filter

A rapidly expanding global population and the inevitable resultant pollution has led to an increased demand, yet constrained availability, of potable water. As such, various filtration systems have sprung up to address the issue. One of the many innovative devices used to convert raw water into a usable product is the sand water filter.

How Do They Work?

Water can be treated to be safe enough to drink using these filters. This is achieved through the biological and the mechanical actions in slow gravity sand, removing small particles and bacteria from the water.

The water is passed through the sand, from the bottom to the top. Once it has passed through the filter, it is not clean enough to drink but can be used for other domestic purposes. There are layers of slime around sand particles, consisting of microscopic organisms such as bacteria and protozoans which eat up the smaller particles while the larger ones settle on the top layers of the sand.

The Limitations

It is important to remember though that sand filters do have their limitations. For example, they won’t sufficiently treat chemically-polluted water. The water treated through sand filters should already be relatively clean, and should not contain chemicals or heavy metals. An entirely different source of water, or separate treatment might be necessary before it can be introduced to a sand filter. They also require a large land area for municipal purposes which might not always be available.

The Advantages

Sand filters do, however, have certain advantages that set them apart from other water filtration methods.

  • They do not require electricity or chemicals to operate. As such, they’re almost the perfect technology for the poorer and more isolated areas, requiring minimalistic maintenance and operator training.
  • They are ridiculously simple to design – a single person can do so in one to four days. As such, they can be setup using the DIY method. This has already been accomplished successfully in the poorer countries like Afghanistan.
  • They have been granted official recognition as superior technology for surface water treatment by the World Health Organization, Oxfam, United Nations and the United States Environmental Protection Agency.

The Maintenance

Although only minimalistic maintenance is necessary, sand filters do need to be cleaned occasionally. This becomes apparent when the outflow of clean water becomes too small. Cleaning basically involves replacing most of the old sand with the new. The existing sand should not be allowed to dry out, and in areas with particularly hot weather, the procedure should be performed as swiftly as possible to prevent the biological matter in the top layer from being damaged. It will take several days before a sufficient quality of clean water becomes available again, and any processed water must not be consumed before then.

It is highly essential to learn about, and know, what kind of sand to use in these filters as sand can contain a variety of contaminants, some of which may well be extremely hazardous.