Limit values refer to legally defined maximum concentrations of certain substances that may not be exceeded in water samples. These values are set in order to protect the environment, public health and the functioning of industrial processes. They apply to drinking water, process water and waste water discharged into the environment.
Technical principles and objectives
Limit values vary depending on the area of application and substance group. In industrial water and wastewater treatment, limit values for the following parameters are typically relevant:
- Heavy metals (e.g. lead, cadmium, copper)
- Nutrients (e.g. phosphorus, nitrogen compounds)
- Organic compounds (e.g. hydrocarbons, pesticides)
- Physical parameters (e.g. pH value, temperature, turbidity)
These parameters ensure that wastewater is treated in such a way that it has no harmful effects on the water or the environment.
Industry-specific limit values
In Germany and the EU, the Wastewater Ordinance (AbwV) regulates the industry-specific limit values. The relevant annexes to the AbwV define the discharge conditions for different industries such as:
- Food industry: Limit values for organic substances and fat content.
- Electroplating industry: restrictions on heavy metals.
- Pulp and paper industry: Parameters for COD, BOD5 and solid particles.
In addition, international norms and standards such as the EU Water Framework Directive or industry-specific requirements apply.
Significance for water treatment
Compliance with limit values has a significant influence on the design and operation of water treatment plants. The following technologies are used to meet the legal requirements:
- Chemical-physical treatment: precipitation, flocculation and sedimentation to remove dissolved substances and particles.
- Membrane process: Reverse osmosis and nanofiltration for the retention of very fine substances.
- Biological treatmentDegradation of organic substances by microorganisms.
- Adsorption: Removal of specific organic pollutants using activated carbon.
Photo: Example of a chemical-physical treatment plant, our ALMA CHEM MCW with gravel filtration for the removal of cyanides, heavy metals, hydrocarbons and chromium
Challenges and practice
Limit values can change due to legal adjustments, which places new requirements on existing systems. Continuous monitoring of discharge parameters is necessary to avoid legal consequences. Online measuring systems that enable real-time monitoring of water quality are used for this purpose.
Support from ALMAWATECH
ALMAWATECH offers comprehensive solutions for reliably complying with limit values in water and wastewater treatment. Our systems are equipped with state-of-the-art measurement technology and software developed in-house. With the help of our online remote monitoring, operating data can be evaluated in real time and measures for compliance can be initiated directly.
For further information on our products, please feel free to contact us at any time!
