Nitrate Removal

Above all, nitrate levels have risen sharply in the ground and surface water found in areas of intensive agricultural activity. As is the case with all environmental problems, preventive measures are the only sustainable solution. However, nitrates remain in the soil for long periods and therefore, treatment plants are essential where the ground water is already polluted.
WABAG offers two processes for nitrate removal: Biological denitrification – BIODEN® process and Electrodialysis – ENR® process. Both processes demonstrate special strengths and therefore WABAG can provide ideal solutions, tailor-made to match specific environmental conditions and individual customer needs.
BIODEN® – Biological Nitrate Removal
BIODEN® is one of the WABAG-developed biological process for ground water denitrification. The process functions according to the principles of heterotrophic, biological denitrification with ethanol or acetic acid as a carbon source. Basically, it consists of nutrient dosage, a biological filter, subsequent aeration for oxygen enrichment, downstream flocculation filtration and final safety disinfection.
The most important advantages of the process are:
– Degradation of pollutant.
– Virtually complete denitrification.
– Excellent partial load capability.
– The generation of relatively small amounts of wastewater with out any Nitrates
– Plant stability and reliability.
– Easy adherence to all guide levels and maximum admissible concentrations.
 BIODEN-brochure
ENR® – Electrodialytical Nitrate Removal
The electrodialysis process enables specific, partial desalination and has been employed for many years for the desalination of sea- and brackish water. On this basis, in co-operation with the Vienna University of Agricultural Sciences, WABAG has developed the ENR®-process for the denitrification of groundwater.
The process: During electrodialysis, salts are separated via ion exchanger membranes by means of an electrical field. Raw water passes through a stack of alternately placed anionic and cationic permeable membranes. The membrane stack is fixed between electrodes, which generate a direct current field. Due to the alternating selectivity of the membranes, cells are formed, some containing diluted water with a low level of salinity, and others filled with concentrated water, which is rich in inorganic salts. Thus, low-nitrate drinking water is produced together with a small amount of concentrate with a correspondingly high nitrate content.
The most important advantages of the process are:
– Nitrate selectivity
– A low general level of desalination
– Reduction of hardness
– Limited space requirement
– Simple operation and quick start-up.