In order to meet the demands of a growing population, it’s essential that we harvest as much water as we possibly can to conserve this precious resource. However, before water can be deemed fit for human consumption, it must go through a rigorous water treatment process. Just as the water quality monitoring process has changed over time, so too has that which treats it.
Nowadays, a typical water treatment process will comprise nine distinct steps. While not all of these steps may be in operation at every treatment facility in the UK (or indeed, across the world), they are the basis of the water treatment industry. The nine steps are as follows:
- Collection. Before the water can be treated, it must first be collected from lakes, rivers and reservoirs. Most often, the water is transported from the source to the treatment plant via a complex network of pumps and pipelines, though natural means (such as rivers) may be used.
- Screening. The first step in the treatment process is to screen the water to remove larger items of suspended materials, such as rubbish, plants, trees, animals and other debris. As the name suggests, these are captured and removed via the use of a large metal screen.
- Chemical addition. At this point, chemicals are now added to encourage smaller particles of suspended matter to clump together and form “floc”. The chemicals used to achieve this purpose are called coagulants and there are many different products available.
- Coagulation. After the coagulant has been added to the water, it must be mixed at varying speeds over a period of time to allow the flocs to form (this part of the process is known as flocculation).
- Sedimentation and clarification. Once the flocs have formed, the water is passed over a sedimentation basin. Here, the clumps of floc particles can settle at the bottom of the basin, where they are removed to a disposal pond.
- Filtration. With the larger particles taken out of the water, it must now be filtered through a variety of media such as sand, gravel or granular activated carbon to remove the smaller unwanted particles which still persist.
- Disinfection. The remaining water has now had the vast majority of its impurities removed, but it may still contain bacteria, viruses and other microorganisms. In order to kill these elements, it must be treated with enough chlorine to be effective but not too much to affect taste or odour.
- Storage. The water is now essentially ready for public consumption, but must be stored until demand for it surfaces. It is most commonly stored in underground or overground tanks. As well as drinking water, there must also be a stored supply of water for emergencies such as fires.
- Distribution. The water is finally sent to homes and businesses around the country via a sophisticated system of pumps, tanks, pipelines, hydrants, valves and meters.
If you’re interested in learning more about how water is monitored for quality, or wish to purchase instruments capable of performing such tasks, check out our Buyers Guide, which has a fully range of suitable products available.
FAQs
Public water systems often use a series of water treatment steps that include coagulation, flocculation, sedimentation, filtration, and disinfection.
What are the different stages of water treatment? ›
The 5 major unit processes include chemical coagulation, flocculation, sedimentation, filtration, and disinfection (described below).
What are the 5 stages of water filtration? ›
THE 5 STAGES OF WATER TREATMENT
- Screening. As water enters a water treatment plant, either from lakes, rivers, or the ground, it passes through a screening. ...
- Coagulation. ...
- Sedimentation. ...
- Filtration. ...
- Disinfection.
Of the many processes involved in the water cycle, the most important are evaporation, transpiration, condensation, precipitation, and runoff. Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.
What is the 7 step water treatment process? ›
Once water has been effectively treated – having gone through the stages of screening, coagulation, flocculation, sedimentation, filtration, and disinfection – it is ready to be stored and distributed to the public.
What is Stage 4 water treatment? ›
Stage 4 – Carbon polishing post filter
This provides the final polish to your drinking water. It ensures removal of unwanted odours and the creation of superb tasting water. This final filter acts as a final check against any organic impurities.
What are the different types of water stages? ›
- THE WATER CYCLE.
- EVAPORATION.
- CONDENSATION.
- PRECIPITATION.
- INTERCEPTION.
- INFILTRATION.
- PERCOLATION.
- TRANSPIRATION.
A five-part filtration system that works using reverse osmosis technology that uses a high-pressure pump to increase the pressure on the feed side of the RO and force the water across the semi-permeable RO membrane, leaving almost all (around 95% to 99%) of contaminants behind in the reject stream.
What are the 5 water phases? ›
Water exists in one of three phases, solid, liquid, or gas. The molecules that comprise a solid, like ice, are arranged in a particular order. The molecules do not circulate but they do move. That is, the molecules vibrate in place around an average location.
What is 6 stage water filtration system? ›
Advanced Filtration: The 6 stage reverse osmosis system combines advanced reverse osmosis filtration technology with a re-mineralization process to provideyou with ultra-pure, alkaline water that is rich in essential minerals.
Step 5: Transpiration
Transpiration is a process similar to evaporation where liquid water is turned into water vapor by the plants. The roots of the plants absorb the water and push it toward leaves where it is used for photosynthesis.
How many stages are in the water? ›
There are four main stages in the water cycle. They are evaporation, condensation, precipitation and collection. Let's look at each of these stages. Evaporation: This is when warmth from the sun causes water from oceans, lakes, streams, ice and soils to rise into the air and turn into water vapour (gas).
Are there 7 stages in the water cycle? ›
What are the 7 stages of the water cycle in order? The seven stages of the water cycle in order are as follows: evaporation, condensation, precipitation, sublimation, transpiration, runoff, and infiltration.
What are the 5 stages of water treatment? ›
Public water systems often use a series of water treatment steps that include coagulation, flocculation, sedimentation, filtration, and disinfection.
What are the 10 steps of water treatment? ›
What Are the Different Stages of Water Treatment?
- Collection. Before the water can be treated, it must first be collected from lakes, rivers and reservoirs. ...
- Screening. ...
- Chemical addition. ...
- Coagulation. ...
- Sedimentation and clarification. ...
- Filtration. ...
- Disinfection. ...
- Storage.
The treatment process consists of nine stages.
- Stage 1 - Lake Pumping Station (LPS)
- Stage 2 - Cascade De-Gasification.
- Stage 3 - Coagulation/ Flocculation.
- Stage 4 - Clarification.
- Stage 5 - Filtration.
- Stage 6 - Carbon Absorption.
- Stage 7 - Ultra Violet (UV) Disinfection.
- Stage 8 - Chlorination After (UV) Disinfection.
These processes are usually divided into four stages known as preliminary, primary, secondary and tertiary treatments. In addition, WWTPs also carry out other processes associated with the by-products obtained in the different treatments.
What are the 5 stages of sewage treatment? ›
Treatment Steps
- Step 1: Screening and Pumping. ...
- Step 2: Grit Removal. ...
- Step 3: Primary Settling. ...
- Step 4: Aeration / Activated Sludge. ...
- Step 5: Secondary Settling. ...
- Step 8: Oxygen Uptake. ...
- Sludge Treatment.
