Aqua2N FAQ

Yes. Aqua2N has been developed for several types of ammonia-rich process waters, including condensates from sewage sludge drying and sludge incineration.

These streams typically contain high ammonium concentrations and low organic content, making them well suited for the Aqua2N process.

No upper limit has been identified so far. Aqua2N is based on chemical equilibrium rather than biological treatment, and the technology has been evaluated for streams with very high ammonium concentrations.

The objective is to achieve low effluent NH4-N concentrations regardless of the incoming nitrogen concentration.

The pH varies in the different steps, but is between pH 5 and 9.

The conceptual design uses electricity only. However, thermal energy could be used to heat the small stream going to the conversion step, which is heated to about 60 °C and maintained through a heat exchanger. If thermal energy is available as steam, the evaporator could use steam instead of, or to replace part of, the electrical power. 

Any condensate that occurs is used as wash water.

Aqua2N is designed to achieve >95% ammonium nitrogen removal.

Stable removal above 80% is therefore achievable under appropriate operating conditions.

CAPEX would be only marginally affected, as most equipment is still required. OPEX would decrease due to lower consumption of process chemicals.

Yes. As a chemical process, Aqua2N can respond quickly to changing conditions and allows removal efficiency to be adjusted more readily than biological processes such as Anammox/deammonification.

The process is designed with automated equipment, buffer capacity, and redundancy for critical components. Aqua2N is also considered more robust than biological processes because it does not depend on sensitive microbial populations.

At the moment, the limitations are more relevant when going smaller rather than bigger. Larger plants can be handled with several lines. If we go much below 7–10 m³/h, the flows in the conversion step become too low; this depends on NH4-N concentration and removal rate. With a very high NH4-N concentration, a smaller scale is possible. 

In general, going larger is less complicated than operating below about 10 m³/h reject flow. 

Ammonium sulfate is an established fertilizer product with an existing market, well-defined quality requirements, and commercialization routes throughout Europe. It can be used directly or as a raw material in fertilizer production.

Ammonium sulfate is a large, commodity-scale fertilizer with high and stable global demand, while struvite represents a much smaller specialty market with higher unit value. 

Ammonium sulfate has predictable demand and global price benchmarks, whereas struvite offers more premium value and strategic sustainability relevance. 

Our business model for fertilizer off-take is based on acting as the off-take partner and managing downstream sales. We purchase, or contractually secure, fertilizer output and are responsible for arranging its sales to commercial partners, typically distributors and local cooperatives. 

These commercial partners are responsible for organizing the logistics chain to the end users, usually farmers or other agricultural operators.