Acidification – lowering of the pH

Acidification of slurry is based on a chemical principle. In slurry there is ammonia (NH3), which is a gas that evaporates, and ammonium (NH4+), which is bound in the slurry in the form of nutrients.

Between these two NH3 and NH4+ there is a chemical balance.

By lowering the pH of the slurry the balance of NH3 and NH4+ shift towards ammonium (NH4+).
Ammonium is a liquid form of N and does not evaporate but stays in the slurry.

Slurryy acidification NH3 to NH4+

Stable – storage – field acidification

The ammonia emissions evaporate from the surface of the slurry, for example slurry under the slatted floor oder from the surface of a lagune. It is on such surfaces that you have the greatest effect from lowering the pH and thereby stop the evaporation.

Ammonia evaporation from barn

Inside a stable, the JH NH4+ system ensures that there is always a large amount of acidified slurry in the slurry channels under the slatted floors. Freshly produced slurry falls into the acidified slurry and is “absorbed” by the acidified slurry and evaporation stopped immediately – directly at the source.


In the system slurry is pumped to a mixing tank, where the sulfuric acid is added lowering the pH from typically around 7 to around 5.5. The process is controlled by pH sensors.

When the desired pH is reached slurry is automatically pumped back to the stable and a smaller amount of freshly acidifed slurry is pumped to the slurry storage tank. The process is repeated typically once a day for each barn / stable section.

Slurry acidification