Micropollutants, also known as trace substances, are chemical substances that can be detected in very low concentrations (micrograms or nanograms per liter) in bodies of water. These include pharmaceutical residues, hormones, pesticides, industrial chemicals and cosmetic ingredients. Although they are only present in minimal quantities, they can have a significant impact on the environment and human health, as many of these substances are persistent, bioaccumulative and toxic (PBT).
Sources of micropollutants
- Household wastewater: Residues of pharmaceuticals, cosmetics and cleaning agents enter the sewer system via household wastewater.
- Industrial wastewater: Chemicals from the production of plastics, paints, varnishes and pesticides are common sources.
- Agriculture: Pesticides and nitrates enter groundwater and surface water via fertilizers and pesticides.
- Hospitals and care facilities: They contribute significantly to pollution through the disposal of pharmaceutical residues.
Challenges during removal
Micropollutants pose a major challenge for conventional wastewater treatment plants, as they are often not completely degraded in biological treatment processes. Their low concentration and chemical stability make it difficult to remove them using standard methods such as sedimentation or flocculation.
Table of contents
Treatment process for the removal of trace substances
1. activated carbon adsorption
Activated carbon, especially in granular form (GAC) or as a powder (PAH), is often used to remove micropollutants. The porous structure of activated carbon provides a large specific surface area on which the molecules of the micropollutants can adsorb. This process is particularly effective for organic compounds and lipophilic substances.
Photo: Our ALMA FIL AK activated carbon filters
2. ozonation
Ozone is a powerful oxidizing agent that can convert organic micropollutants into less harmful compounds or mineralize them completely. Ozonation is particularly suitable for micropollutants such as hormones, pharmaceuticals and pesticides.
3. Advanced Oxidation Processes (AOP)
AOPs combine oxidizing agents such as ozone or hydrogen peroxide with UV radiation to generate hydroxyl radicals. These highly reactive radicals efficiently oxidize a wide range of organic micropollutants.
Photo: UV reactor in conjunction with the dosing of ozone or hydrogen peroxide in our ALMA OXI UV system
4. membrane process
- Nanofiltration (NF) and reverse osmosis (RO) provide a physical barrier against micropollutants. They separate the dissolved molecules based on their size and charge.
- Micro- and ultrafiltration can be used in combination with adsorption processes or biological systems to increase efficiency.
Photo: Our ALMA OSMO Process reverse osmosis system for removing PFAS, installed in the ALMA MODUL technical room container
5. biological processes
- Activated sludge process and MBBR (Moving Bed Biofilm Reactor): Some microorganisms are able to break down certain micropollutants.
- Biofiltration: In biofilter systems such as the ALMA BHU BioFil, biofilms can be used in a targeted manner to eliminate specific micropollutants.
Photo: 3D design of our ALMA BioFil Compact biofiltration system
6. chemical-physical treatment
CP systems combine several physico-chemical processes to effectively remove micropollutants from wastewater. Processes such as precipitation, flocculation, neutralization, filtration and oxidation are used. The efficiency of this method is particularly evident in the pre-treatment of industrial wastewater with high concentrations of pollutants.
Advantages:
- High flexibility in the removal of organic and inorganic micropollutants.
- Effective pre-treatment for downstream processes such as membrane technology or biological systems.
Applications in various industries
Pharmaceutical industry
The wastewater is often contaminated with pharmaceutical residues, which are treated using membrane processes or AOP.Chemical industry
Various organic micropollutants occur here, which can be efficiently removed using a combination of ozonation and activated carbon.Municipal wastewater treatment plants
A fourth treatment stage is increasingly being implemented to remove micropollutants and sustainably improve water quality.Plastic production and recycling
Wastewater from plastic production often contains additives and microplastics. Trace substances such as plasticizers or flame retardants can be effectively removed using combined processes such as activated carbon adsorption and membrane technology.Disposal company
CP systems and AOPs play a key role in the treatment of hazardous liquid waste such as waste oils or solvents in order to break down hazardous micropollutants.Electroplating industry
Electroplating produces wastewater with traces of heavy metals and organic complexing agents, which are removed using chemical-physical and membrane processes.- Surface treatment
Surface treatment includes processes such as painting, coating and metal finishing, which generate wastewater containing micropollutants such as solvents, heavy metals and organic compounds. Chemicals such as cyanides or chromates are used in electroplating in particular. Chemical-physical processes such as CP systems and membrane processes are used here.
Conclusion
Micropollutants represent a key challenge for modern water and wastewater technology. They require the use of advanced technologies and a targeted combination of processes to minimize their harmful effects on the environment. ALMAWATECH offers comprehensive solutions for the removal of micropollutants, adapted to the specific requirements of various industries and applications.
For further information on our products, please feel free to contact us at any time!
