The 5 most common steps in a water treatment system
In a water treatment project, various technologies are used to effectively remove specific contaminants and prevent harmful discharges. In this article, we outline the five most common steps in a water treatment system. However, it is important to remember that each project has its unique requirements, and customized solutions may be needed in addition to these fundamental steps.
1. pH Adjustment
Since most flocculating chemicals are more effective at certain pH levels, we recommend pH adjustment before dosing flocculants/precipitants. This improves flocculation and ensures the correct outgoing pH value while minimizing the costs of subsequent dosing. If pH needs to be lowered, we typically add carbon dioxide instead of strong acids, which are often corrosive and potentially harmful for personnel to handle. If pH needs to be raised, we recommend workplace-friendly alternatives instead of using sodium hydroxide (caustic soda).
2. Flocculation
Initially, treating particles and particle-bound pollutants is often the most crucial and fundamental step in the treatment process. Effective particle separation typically requires some form of flocculation (and possibly precipitation, see below), often combined with sedimentation. The principle involves adding flocculants to cause fine particles to form larger aggregates, called "flocs," which then settle in a sedimentation volume – usually in sedimentation containers, lamella separators, or ponds. Here we use our biodegradable flocculant agent, chitosan, which is dosed within our HydroBox.
Dissolved Substances
For treating dissolved pollutants, a combination of precipitants and some form of filtration is usually used. Precipitation agent often involves both flocculation and precipitation and is dosed before the sedimentation step (see above), causing the dissolved substances to "precipitate" into particles that then flocculate with other particles. The flocs then sediment in a sedimentation volume, following the principle described above. Precipitation can also be achieved by varying the pH level of the water. However, some dissolved substances require some form of filtration. This can include carbon-based sorption filtration (activated carbon, BioMedia®), where the principle is that the filter media consists of materials with extremely small pores to which dissolved pollutants can bind.
3. Sedimentation
This is a fundamental water treatment process that removes particles and contaminants by allowing them to settle in sedimentation containers or lamella separators, where they form sediment and separate solids from the water. The sedimentation process is enhanced by integrating our HydroBox into the treatment system.
4. Filtration
Filtration using BioMedia®, activated carbon, ion exchangers, and physical filtration is used to remove particles and dissolved pollutants such as heavy metals, PFAS, and organic contaminants.
5. Monitoring
Continuous sampling during the projects is crucial. It is only through continuous and flow-proportional water sampling that you can determine if the chosen technology is actually working. The data collected should be documented and reported to the supervisory authority and/or the municipality.
