Color is a general determinant of water cleanliness. There are multiple causes for color change to occur in water. Possibilities vary from particles or air-bubbles that do not pose a direct threat to human health or color change may occur due to the presence of disinfection by-products (DBP) and natural organic matter (NOM). In the latter case, human health is a concern and it would be imperative to treat the water accordingly. DBPs and NOMs are not favorable contaminants to say the least. DBP is essentially a chemical by-product that occurs when certain elements interact with NOM particles. They are also carcinogenic and can be ingested through the skin. Therefore, the concern for color removal from water applies to multiple applications in addition to drinking application. Studies have shown that traces of DBPs have been found in human blood from other applications like dish washing or showering.
Industries may cause the water color to change due to different production processes. For example, in the textile industry, the presence of ions that occurs when dying textiles adds color to the water. Turbidity is another factor that contributes to colored water. When there is a high level of suspended solids, the turbidity increases and the clarity of the water is affected and often the color changes.
Color may also be a manifestation of other contaminants as well. For example, when iron is present in water it turns brown or reddish. If algae is present in water, the color would turn green. In addition, people generally do not want to drink water that is not clear. Therefore, color removal from water is important to ensure contaminants are filtered out and the water is appealing for drinking purposes. The most ideal solutions to this issue would be the Nanofiltration system and Activated Carbon filter.
Nanofiltration (NF) systems are similar to the make of reverse osmosis systems. However, the degree of filtration is what differentiates the two. Nanofiltration systems is an ideal treatment method for water containing low amounts of total dissolved solids (TDS) or natural organic matter. If softening or demineralization is needed, NF system would be the best system to tackle both. The NF system is unique due to its dual function of filtration and softening. Due to its softening membranes, NF systems are able to filter out certain level of contaminants while also softening the water. The level of filtration however, is not as thorough as the reverse osmosis system, but it does remove contaminants that would be causing water to be colored. This process occurs through membrane filtration.
Activated Carbon Filter:
Activated Carbon (AC) filter is the most common form of treatment for removing color from water. Along with color removal from water, this conventional treatment is designed to absorb particles and organic contaminants in water that may result in bad tastes and odors. Turbidity and iron can also be filtered through this treatment method. However, it is important to understand that Activated Carbon filters do not remove bacteria. Therefore, characterized as filtration rather than purification. AC filters are one of the least expensive methods of treatment and can be very effective in reducing dissolved solids.
- Color removal from water
- Reduces TDS
- NF softens water
- Drinking water