A water treatment plant is a unit where raw water (or contaminated water from the source) is treated using technologies like Reverse Osmosis, UV Disinfection or Cartridge filtration to generate clean and safe water.
The end use of the treated water may include drinking, irrigation, industrial water supply, river flow maintenance, or many other purposes.
In this article, we’ll help you understand water treatment better:
Why do we need water treatment plants?
With increasing drinking water shortages amid the global population, the need for water treatment plants in the UAE and the region has also risen.
Of the planet's total water reserves, freshwater amounts to just 2.5%, of which only 0.4% is fit for human consumption. With increasing pollution, and the introduction of harmful chemicals, the water in natural water bodies is not safe for direct consumption. Hence, in the recent past, there has been an increasing need for wastewater treatment in UAE and the region among commercial establishments, communities, industries, and agriculture.
In addition, a rise in awareness and acceptance of water recycling offers a sustainable and reliable solution for water conservation and management.
How does a water treatment plant work?
At water treatment plants in the UAE or across the globe, the water undergoes various processes before it is deemed fit for various applications.
The three main stages are primary (filtration or pre-filtration), secondary (membrane-based treatment like ultrafiltration or reverse osmosis), and tertiary treatment (disinfection or chemical dosing). Some plants also add a pre-treatment stage before the primary treatment process.
Suspended solids and algae are removed in the first stage of filtration. This prefiltration process also help protect the RO membrane or filters used in the second stage of the water treatment process. Not all plants use tertiary treatment, it's only used when they need their product water needs to meet a certain standard.
The tertiary treatment provides extra filtration and disinfection. For example, in case reverse osmosis is used as the secondary treatment method, an additional chemical dosing unit may be added to the process to make the RO water fit for human consumption.
Methodologies used in water treatment
After water analysis and understanding the intended use of the water, which could be irrigation, industrial or drinking, a suitable treatment method is selected. Water analysis is carried out using instruments like MyronL that generate reading based on set parameters. This indicates the type and amount of suspended and dissolved solids in water.
Generally, water treatment plants use a combination of methods for the best results. Multimedia filtration could be used when the source water contains large particulate matter but no harmful chemicals and needs to be used for irrigation. However, Ultrafiltration and/or reverse osmosis (RO) will need to be used along with a chemical dosing unit when the same water needs to be used for drinking.
Here are some of the different types of water treatments methods used based on the particulate matter present:
Conventional filtering methods
This method is used when bigger particles, between 1,000µm to 10µm, like sand, large bacteria and certain types of algae, are present in the water. It consists of the addition of coagulant chemicals, coagulation-flocculation, sedimentation, multimedia filtration, flash mixing, and filtration.
Microfiltration is a pressure-driven separation process for concentrating, purifying or separating macromolecules, colloids and suspended particles from water.
For this, contaminated fluid is passed through pore-sized membranes to separate and remove suspended particles. Particles between the size of 10µm and 0.1µm, like clay, asbestos fibres, and cysts, are removed during this stage.
Ultrafiltration is a membrane technique used to remove dissolved and colloidal material in low transmembrane pressure. In this process, the water is forced through a semipermeable membrane. Dissolved metal ions as low-molecular weights or hydrated ions could easily transmit UF membranes because their membranes have pores that are greater than dissolved metal ions.
The most advanced method in the membrane-based water purification process is reverse osmosis, which is used on brackish water or seawater to make it fit for human consumption. During this process, water is passed through RO membranes using high pressure to separate the contaminants and let only clean water pass out. At this stage, even the tiniest metal ions and aqueous salts (smaller than 0.001µm) are removed.As a result, the solute is kept on the membrane’s pressurised side, and the pure solvent is allowed to pass to the other side. A combination is used based on the raw water source and application of the treated water.
The disinfection process uses technologies like chemical dosing or UV to remove bacteria or add essential chemicals to make the water fit for consumption. Disinfection is most often the last phase of treatment before point of use.
If you have been looking for the best water treatment expert, then you have arrived at the right place. Advanced Watertrek has a range of products and solutions for varying water treatment needs. We have been providing end-to-end solutions that have gained our reputation over the years. Contact us or get a quote from us if you are looking for a new system or for maintenance of your existing one.