Phosphorus and biologically active nitrogen are valuable nutrient resources. Bioremediation with macroalgae
is a potential means for recovering nutrients from waste streams. In this study, reject water from
anaerobically digested sewage sludge was successfully tested as nutrient source for cultivation of the
green macroalgae Ulva lactuca. Maximal growth rates of 54.57 ± 2.16% FW d1 were achieved at reject
water concentrations equivalent to 50 lM NHþ
4 . Based on the results, the growth and nutrient removal
was parameterised as function of NHþ
4 concentration a tool for optimisation of any similar phycoremediation
system. Maximal nutrient removal rates of 22.7 mg N g DW1 d1 and 2.7 mg P g DW1 d1 were
achieved at reject water concentrations equivalent to 80 and 89 lM NHþ
4 , respectively. A combined
and integrated use of the produced biomass in a biorefinery is thought to improve the feasibility of using
Ulva for bioremediation of reject water.
2