High rate hydrogenotrophic denitrification of drinking water

Prof. Michal Green | Civil and Environmental Engineering
Prof. Ori Lahav | Civil and Environmental Engineering


Sustainability and Energy

The Technology

A novel pressurized high rate hydrogenotrophic reactor for denitrification without gas purging. This invention shows that during continuous operation a gas–liquid equilibrium is established in the reactor according to Henry’s law and excess N2 gas is carried out by the effluent in dissolved form. Therefore, no gas purging is required and H2 loss is limited only to the dissolved hydrogen in the effluent.

The reactor is operated as a trickling filter where water is recirculated over biofilm carriers with high surface area.


  • Use of hydrogen is cleaner, by-product free and prevents using organic material thus requires less intensive post treatment of drinking water
  • Use of hydrogen instead of organic material results in slow bacterial growth and minimum reactor clogging and therefore requires less maintenance and cleaning
  • Safer & more economic process due to no hydrogen discharge to the environment

Applications and Opportunities

  • A safe, clean and cost-effective method for nitrate removal from contaminated drinking water
  • The main drawbacks limiting the use of hydrogenotrophic denitrification are safety concerns, poor hydrogen utilization and low denitrification rates due to low solubility of hydrogen with the resulting low transfer rate
  • The current invention proposes a new hydrogenotrophic denitrification system that overcomes these drawbacks as it is operated as a closed system
arrow Business Development Contacts
Oz Mahlebani
Business Development Manager, Engineering