Danish water technology in Hungary
- purified drinking water using only natural processes

12,000 inhabitants in the town of Tolna in Hungary 135 km south of Budapest are enjoying pure drinking water from a new water utility. The water utility is the first of its kind in Hungary, using no chemicals to make the water drinkable. The solution is supplied by EUROWATER.

Tolna waterworks from the outside
 

Drinking water

Water purification is the removal of contaminants from untreated water to produce drinking water that is pure enough for human consumption. World Health Organisation (WHO) guidelines are generally followed throughout the world for drinking water quality requirements. In addition to the WHO guidelines, each country or territory can have their own standards.

In the European countries the EC directive on drinking water must be followed. In general the selection of treatment method is greatly related to the water source available and to the standards set out by the local authorities. The following table shows different water sources, their related water treatment method as well as the level of complexity, costs and environmental impact.

The case will show how ground water in Hungary was turned into drinking water using only air - a method with low environmental impact as well as low complexity and low costs.

Water source

Water treatment method

Complexity
and costs

Environmental
impact

Sea water Desalination.
Process of removing salts from the water using reverse osmosis.
High High
Surface water (lakes, swamps, rivers) Chemical and mechanical treatment.
Flocculation, sedimentation, filtration and disinfection using chemicals for coagulation and disinfection.
High High
Ground water Chemical treatment.
Pre-chlorination, dosing of oxidation chemicals and sand filtration.
Medium to high High
Natural processes.
Treatment using atmospheric air and filtration in pressure filters.
Low to medium Low to medium

 

The standard model - chemical treatment

Historically, all drinking water in Hungary is produced using a treatment process of dosing oxidation chemicals followed by sand filtration. The chemicals widely used are sodium hypochlorite (NaOCl), potassium permanganate (KMnO4) and chlorine gas (Cl2).

The Danish model - a chemical free solution

In Denmark the drinking water quality requirements are even tougher than the requirements in the EC directive. The available water source is 100% ground water. The water treatment method used in Denmark is based on a philosophy using only natural processes such as oxidation and filtration. For 75 years, EUROWATER has manufactured and supplied pressure filters for water purification.

In the EUROWATER standard programme, the raw water is oxidized with atmospheric air to aid the filtration process inside a pressure filter with sufficient filter media - individually designed for the project. The EUROWATER pressure filters are designed specially for the drinking water treatment.

Benefits using a chemical free solution for purification of drinking water

If designed properly, the chemical solution as well as the chemical free solution will do the job: produce drinking water!

However, there are some very clear benefits using only oxidation and filtration for producing drinking water:

  • Good working environment. The working environment is very safe without the handling and storage of dangerous chemicals.
  • No wastewater problems. EUROWATER pressure filters are designed for low wash water consumption and the rinse water is not harmful. Therefore, there are no risks of effluent water with traces of chemicals.
  • Completely safe operation. No risk of residual chemicals in the drinking water.
  • Ease of use. Dosing of chemicals requires a very demanding operation and attendance as well as controlling and monitoring.
The EUROWATER way: Purify drinking water using only natural processes.
 

The Tolna project

The water source in Tolna is ground water from 60 meters deep well. The water contains some impurities that must be removed in order to meet the standards in the EC directive, including iron, manganese, hydrogen sulphide, and ammonium. EUROWATER has designed, manufactured and installed the water treatment for the new water utility in Tolna. The solution consists of two parallel lines - with a capacity each of 50 m³/h – in order to ensure safe and reliable operation.

Parameter

Unit 

Ground water 

Quality requirements
[EC directive] 

Drinking water
after treatment 

Iron mg Fe/l  1.7 0.2  0.02 
Manganese mg Mn/l 0.45 0.05 0.01
Ammonium mg NH4/l 0.5 0.5 0.1

 

The commissioning of the water treatment was performed in the beginning of 2012. The status is today that the water quality has been very good and by far meets the required standards. We believe that Hungary will see more chemical free solutions in water utilities in future.

Right side: Aeration system consisting of compressors. Left side: Air blower for high quality backwash.
Filtration system with pressure filters from EUROWATER

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