Guarantee water treatment plants performance

The treatment processes implemented to produce drinking water depend on the quality of the raw water (depending on the resource used) and the quality of the water that is to be obtained (for compliance with drinking water standards).
 
Initially, the pre-treatment stages (screening, sieving, etc.) make it possible to retain pollutants and coarse particles.
 
Then, decanting/clarification, then filtration (on sand or ultrafiltration membranes in particular) retain the fine particles and organic matter.
 
Adsorption on activated carbon retains micropollutants such as pesticides. Low-pressure reverse osmosis makes it possible to retain dissolved salts such as limestone, or certain pollutants, and to retain micropollutants.

In the case of seawater desalination, high-pressure reverse osmosis is used.
 
Remineralisation makes it possible to give sufficient minerality to naturally very soft water or to water from a desalination process.

Finally, the disinfection stages, mainly by ultraviolet, chlorination, or ozonation, guarantee the absence of microbiological pollution in the distribution networks.

 

No drinking water treatment plant combines all these steps: the treatment systems are adapted to raw water, from simple chlorination for excellent quality groundwater to complex processes for surface water of degraded quality.

A wastewater treatment plant is a facility designed to treat domestic, industrial or agricultural wastewater to make it suitable for discharge into the environment without causing pollution. Below we describe the most common wastewater treatment steps: 

The first step is pre-treatment, which involves removing large debris such as branches, leaves, plastics and other solids from the water through a screening or coarse filtration process.

This is followed by primary treatment, in which the water passes through settling ponds where the finer solid particles settle to the bottom, forming primary sludge, while the greases and oils float to the surface and are removed. This process removes about 60-70% of suspended solids and suspended solids.

Then, the water is biologically treated through basins where bacteria and microorganisms break down the dissolved organic matter. This process uses aeration to deliver oxygen to microorganisms, promoting their growth and metabolic activity. The biological sludge produced in this process is then separated from the clarified water.

Depending on current regulations, it may be necessary to add advanced treatments that remove residual nutrients such as nitrogen and phosphorus, as well as other persistent pollutants that may not have been removed in the previous steps. This may involve the use of special filters, chemicals, or other advanced technologies.

Before being released into the environment, water is often disinfected to kill remaining pathogens such as bacteria, viruses, and parasites. Common methods of disinfection include the use of chlorine, ozone, ultraviolet or other chemicals.

Once treated, the water can be discharged into a stream or river if it meets environmental standards, or it can be reused for non-potable purposes such as watering green spaces.

Overall, wastewater treatment plants play a crucial role in protecting the environment by treating wastewater to avoid pollution of natural water resources.