Process & contact
Nutrient recovery from drinking water treatment.
Adaptation possible for tertiary N-removal in sewage plants.
Solution of nitrate with K, S, Ca and Mg for local fertigation.
Ion-exchange is today widely used to remove nitrates from drinking water, but uses salt for regeneration. This generates a phytotoxic sodium nitrate brine, which has to be disposed. The Agua DB process uses water quality potash (KCl) for regeneration, instead of salt, in significantly lower quantities, so generating liquors rich in sulphate, nitrate and potassium, which can be used for fertigation in local agriculture. These can partially replace synthetic fertilisers and reduce use of potash by farmers, so reducing salination (Cl input) to farmland.
A three months pilot project with Affinity Water (a UK drinking water company supplying 3.6 million people), showed effective nitrate removal down to 5 mgN/l. The resulting fertigation solution was demonstrated to be effective for use in hydroponics.