Odour pollution control system at the Arazuri WWTP

Emission monitoring network to detect possible diffuse emissions and odour episodes.


The Arazuri wastewater treatment plant (WWTP), managed by the Mancomunidad de la Comarca de Pamplona, expressed their interest in knowing the critical points where odour episodes could occur due to high levels of H2S.

To this end, it was decided to implement a system for measuring environmental variables to improve decision-making in order to reduce the impact that odour episodes could have on nearby populations.

A study was carried out at different locations using an air quality monitoring system capable of detecting diffuse emissions of gases such as H2S and establishing the most appropriate arrangement of the sensor network based on the areas with the greatest potential for odour problems.


Supply of the Kunak AIR system equipped with an H2S sensor providing real-time data and an anemometer to monitor wind direction and speed.

  • Emission monitoring for the detection of possible diffuse emissions and odour episodes.
  • Early warning system for threshold exceedances to prevent possible odour episodes.
  • Data analysis for validation of the solution, detection of critical points and optimal locations.
  • Protection against bad odours to nearby populations.
  • Kunak AIR Cloud platform for operational management and visualisation and analysis of data from the monitoring network.


Development and validation of an environmental monitoring solution with the following functionalities:

  • Early detection of odour episodes with a real-time alert system at the Arazuri WWTP.
  • Validation of the solution for H2S monitoring with ranges between 0 and 2,000 ppb.
  • Definition of the optimum locations for monitoring pollution episodes (perimeter ring, raw water inlet and sludge treatment area).
  • Generation of periodic reports.