Nutrient removal from wastewater discharges is an increasing challenge for
water authorities, as regulatory authorities tighten discharge standards to
avoid eutrophication problems in receiving waters. Significant costs are a
ssociated with the extra treatment processes required to meet these new dis
charge standards. The most widely used technologies for nutrient removal in
clude biological nitrification/denitrification for nitrogen removal and met
al salt precipitation for phosphorus removal. Both approaches result in the
nutrient being made unrecoverable for possible use as a fertiliser. An alt
ernative to these conventional technologies which can provide for recovery
of the nutrient as a commercial fertiliser could be the production of magne
sium ammonium phosphate (struvite).