The water purification market has gained immense fascination in the UAE (United Arab Emirates) since the last decade owing to heightened health awareness. The scarcity of fresh potable water for drinking, high salinity values in existing groundwater reserves, high cost associated with desalination plants to produce fresh water, and limited re-use of water has further added to the increasing demand of home filtration systems. Water purification systems provide a good sustainable, economic, and environmentally friendly treatment option for potable drinking water. Water purification systems can be used as a more cost-effective and healthy alternative to bottled water. Research studies indicate that the toxins from plastic bottles can contaminate water and UAE’s high temperatures act as a catalyst to further advance this process.
There are two types of water purification systems – Point of Entry (POE) or Whole- House Filtration System and Point of Use (POU) Filtration System. Whole-house filtration systems are water treatment devices that are installed on the main supply line (usually near the water meter or pressurized storage tank) and treat all the water used in the home (at the point of entry into the home; thus the name). Whole house filtration systems are good to clean all the water before it enters the house and gets distributed to various faucets and showers. POE systems eliminate the need for individual filters at each faucet and showers. A single system can help provide a solution for taste and odor issues, dry scalp, skin irritation issues caused due to excess chlorine/chloramine disinfectants in finished water. Some of the most commonly used whole house filtration systems are water softeners, reverse osmosis systems, etc.
Point of Use (POU) filtration systems is water treatment devices that are installed on a single tap (or multiple taps) and intended to treat water for cooking and drinking purposes. Some of the most common types of POU filtration systems are carbon filters. This article provides a brief overview of whole house filtration systems including types, advantages, types of technology used in whole-house filtration systems.
Diagram Courtesy: 3M Whole House Water Filtration Systems
TREATMENT TECHNOLOGIES FOR WHOLE-HOUSE FILTRATION SYSTEMS
REVERSE OSMOSIS –
Reverse Osmosis Water Treatment Systems have been widely adopted by customers as an effective and complete solution to provide potable drinking water. (RO) Reverse Osmosis is a water treatment process in which water is forced through an extremely fine semi-permeable membrane to remove contaminants and other impurities from water. They are effective in removing bacteria (E. coli, Samonella), protozoa (Guardia, Cryptosporidium), common chemical inorganic contaminants such as sodium, chloride, lead, fluoride, etc. A brief summary of the reverse osmosis process is described below:
- A whole house reverse osmosis system is placed between water meter or well pressure tank and the point of entry where water enters the house
- As water enters the house, it first passes through a pre-filtration stage where contaminants such as chlorine, iron, manganese, iron, sulfur
- After the pre-filtration, water is passed through semi-permeable membranes under high pressure
- The semi-permeable membrane constitutes the core of the RO systems and comes in two options: CTA (cellulose triacetate) which is chlorine tolerant and TFC/TFM (thin film composite/material) which is not chlorine tolerant.
- After passing through the membrane treatment, water is passed through an atmospheric storage tank until needed.
Reverse Osmosis systems provide a cost-effective and low maintenance treatment option for clean drinking water.
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ULTRA-VIOLET PURIFICATION –
The ultraviolet treatment uses UV light to remove organic contaminants. Light at 254 nm wavelength is used to disrupt the genetic composition of the microorganisms eliminating the possibility of reproduction. UV treatment is highly effective in removing bacteria (E. coli, Samonella), protozoa (Guardia, Cryptosporidium), and some viruses. This treatment is however not useful in removing chemical contaminants.
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ION EXCHANGE (WATER SOFTENER)
Water Softeners typically use Ion Exchange treatment to reduce the hardness causing chemicals such as calcium and magnesium. It can also be used to remove iron contaminants to some extent. Hard water results in clogging of water pipes, staining of dishes and laundry, and difficulty in using soaps and detergents due to its inability to forming a lather. Water Softener removes the hardness inducing calcium and magnesium chemicals in its conditioning tank and flushes those periodically to the drain. A brief summary of the reverse osmosis process is described below:
- A typical water softener consists of a tall, narrow water-softener tank, and a short, wide brine tank.
- The softener tank is connected to the main water supply line.
- A fill tube connects the brine tank to the softener tank and a discharge hose runs from the softener tank to a nearby drainpipe or dry well.
- Softener tank is filled with specially formulated resin beds that are permanently attached to the tank
- The brine tank has removable covers so that it can be filled with salt or potassium chloride
- Water enters the top of the softener tank and percolated through the negatively
- charged resin beds that attract the positively charged minerals from the water
- The mineral deposit adheres to the resins and softened water flows through the brine tank and then through the house.
In conclusion, whole-house water filtration systems provide an overall cost-effective, long term, and low maintenance treatment solution for clean drinking water.
REFERENCES
1. https://www.export.gov/article?id=United-Arab-Emirates-Water
2. https://www.ead.ae/SitePages/Home.aspx
3. https://www.khaleejtimes.com/business/water-purifier-market-to-touch-dh20b-by-2020
4. https://www.environmentalatlas.ae/resourceOfLife/waterFuture
5. https://www.bloomberg.com/press-releases/2019-05-23/water-purifier-market- witnessing-growth-due-to-rising-government-investment-for-industrial-water-purification-tmr
6. https://www.mae.gov.nl.ca/waterres/training/adww/treatmentalternatives/pres11_willard_deon_point_of_use.pdf
7. https://www.3m.com/3M/en_US/company-us/all-3m- products/?N=5002385+8709322+8709409+8740556+8740542+8711017+3294857497&rt=r3
8. https://www.freshwatersystems.com/blogs/blog/what-is-a-whole-house-water-filter-and-how-does-it-work
9. http://www.canadianwaterfilter.com/RO.htm
10. http://www.nsf.org/consumer-resources/water-quality/water-filters-testing-treatment/home-water-treatment-system-selection
11. https://www.skillingsandsons.com/blog/whole-house-reverse-osmosis-well-water-treatment-systems
12. https://www.popularmechanics.com/home/tools/a28280250/water-softener/