Biological denitrification DWTP project in Formiche Alto (Teruel, Spain)


In 2016 – 2017 Ingeobras, a company that works closely with BIOBOX®, carried out a project to create a denitrification drinking water treatment plant in Formiche Alto, Teruel (Spain). In this project, Filtralite® Pure was used as a support for the biofilm (material from the company Filtralite, a BIOBOX® co-founder company) and the biological denitrification technology Puremust-SN®.

This was a project designed to remove an excess of nitrates in the drinking water of the village of Formiche Alto, Teruel (Spain). The supply had high levels of nitrates (NO3), around 90 Milligrams/liter, significantly above the limits established in R.D. 140/2.003.

IIn order to guarantee the quality of the water supply from the existing catchments, it was necessary to install a denitrification drinking water treatment plant in Formiche Alto. This DWTP is made up of denitrification, filtration and chlorination stages. As in all plants designed by Ingeobras, control and automation elements were added. These mechanisms help to optimize the operation of the installation and ensure compliance with the regulations governing the sanitary criteria for the quality of water for human consumption. In addition, it was designed so that the operation of the equipment that make up the denitrification drinking water treatment plant would be automatic. The filtering and washing operations are carried out automatically and programmed.

This DWTP has a removal efficiency of 80%. It obtains a final value of Nitrates NO3 in the outlet water lower than 25 milligrams/liter. This result guarantees a conservative safety margin in relation to Spanish regulations.

The amount of backwash water required is 1.5% of the total filtered water produced, which also fulfills the characteristics for discharge into public watercourses.

The plant has an automatic operation that reduces operating costs. With the Puremust-sn® technology, in a DWTP designed to remove 60 milligrams/liter of NO3 with a daily flow of 1000 m3, the total operating cost is about 0.11 €/m3 with the following cost breakdown

  • 0.08 €/m3 for carbon source.
  • 0.02 €/m3 for energy.
  • 0.01 €/m3 for maintenance.
  • In addition, the Filtralite® Pure filter media, which is the heart of the system, has a service life of more than 20 years.

Moreover, the CAPEX of the project to build the DWTP is substantially lower compared to other solutions (reverse osmosis, electrodialysis, distillation or chemical reduction). This is due to the simplicity of the technology used and the fact that practically 100% of the raw water is obtained as treated water. Biological denitrification in the DWTP eliminates between 80 and 95% of nitrates, being the most effective and, at the same time, efficient of all technologies.

In conclusion, this design to denitrify drinking water biologically is the best option, in terms of water quality, efficiency and effectiveness, in addition to having the most competitive CAPEX and OPEX in the market. The process is very robust and reliable with a strong economic and environmental sustainability component.

Technologies used:

Plant characteristics:

  • Design flow rate: 20 m3/hour
  • Inlet nitrate concentration: 90 Milligrams liter
  • Outlet nitrate concentration: < 25 Milligrams liter (RD140/2003 requires less than 50)
  • Filter media: Filtralite®Pure.

Plant steps:

The drinking water treatment line consists of the denitrification Potabilizer at Formiche Alto:

  • Denitrification by Bio-Filter to remove nitrates.
  • Physical Filtration to remove possible suspended solids.
  • Disinfection with Chlorine to eliminate microbiology as in any DWTP.