Different Water Filtration Methods Comparison

A fine strainer or activated carbon was used to filter the water. Filters are ineffective at removing many common contaminants such as arsenic, bacteria, copper, lead, nitrates, parasites, sodium, and viruses, although they do reduce unpleasant tastes and odors. As the organic material left in the filter begins to decompose, it can become a breeding ground for bacteria.

Another disadvantage is that it is difficult to determine when the filter should be replaced. When a bad taste or smell returns, some manufacturers recommend replacing the filters. In reality, a filter can continue to control taste and odor long after it has lost its ability to remove tasteless and odorless organics such as THM, which are byproducts of chlorination.

Physical or chemical filtration are the most common methods of water filtration.

To remove larger impurities, physical filtration uses a strainer or filter. This filtration method works like a sieve and removes heavier impurities.

Water is chemically filtered by passing it through an active material. The adsorption properties of this material can remove a wide range of contaminants. Both types of filtrations are covered by the various filtration methods we discuss below.

Many different types of sediment, taste, and odor are removed by various water filtration methods.

Depending on the type of contaminant, these methods can result in better tasting and purer drinking water or prevent scale buildup by providing soft water.

Take a look at our list of the six most common water filtration methods to get a better idea.

Water has long been treated with ultraviolet radiation as a germicidal agent. Low-pressure mercury lamps emitting UV light with a wavelength of 254 nm are effective in killing bacteria and viruses and disinfecting water. Inactivation of the microorganism occurs when the UV light is absorbed by the DNA and proteins in the microbial cell.

UV lamp technology has recently advanced so that special lamps can be made that emit both 185 nm and 254 nm UV light. Organic compounds need to be photo oxidized, so this wavelength combination is required. The total organic carbon (TOC) content in high purity water can be reduced to 5 ppb with these special lamps.

Reverse osmosis is the most cost-effective method of removing 90 percent to 99 percent of all contaminants (RO). The pore structure of RO membranes is much more compact than that of UF membranes. Almost all particles, bacteria, and organics with a molecular weight greater than 300 Daltons can be rejected by RO membranes (including pyrogens). In fact, reverse osmosis technology is used by the majority of major water bottling plants. Natural osmosis occurs when two different concentrations of solutions are separated by a semi-permeable membrane. Osmotic pressure forces water through the membrane, diluting the more concentrated solution and resulting in equilibrium.

In water purification systems, hydraulic pressure is used to counteract the osmotic pressure of the concentrated solution. The concentrated solution is pushed downstream of the membrane, where it is collected by pure water. Because RO membranes are very restrictive, they have a low flow rate. Storage tank capacity must be sufficient in a reasonable amount of time.

Reverse osmosis effectively removes total dissolved solids (TDS), turbidity, asbestos, lead and other toxic heavy metals, radium, and many dissolved organics from water. Chlorinated pesticides and the majority of VOCs with a higher molecular weight will also be removed. When reverse osmosis and activated carbon filtration are combined, they provide the most effective treatment for a wide range of water impurities and contaminants.

In many homes, carbon filtration is a popular method of water filtration. It entails removing impurities as well as any unpleasant odors or tastes by utilizing carbon's active absorption capabilities. It works best against chemicals and gases, but it can also kill bacteria.

The activated carbon used is a porous charcoal-based carbon. Because of the reduced oxygen supply during its formation, it acts like a sponge with a large internal surface area. It also causes many gaps in the molecules. Adsorption, as a result, can be used to trap a wide range of impurities. Rather than solids dissolving into liquids, this process involves solids or liquids capturing liquids or gases.

With activated carbon filtration, impurities such as chlorine-based pollutants, certain insecticides, and industrial solvents are easily removed. It is ineffective, however, at removing hardness from water or treating heavy metals such as sodium, fluorine, or nitrates. There are carbon filters that are specifically designed to treat certain heavy metals, but they may be more expensive.

The type of carbon used has a significant impact on the effectiveness of this system. The diameter of the pores formed in the carbon filter and the rate of impurity diffusion also have an effect on the adsorption process. As a result, people usually combine this method with other treatment methods for maximum efficiency.