Microalgae as a multibenefit natural solution for the wastewater industry: A UK pilot‐scale study

Commercialization of microalgae for wastewater treatment (WWT) is limited due to the large footprints and long hydraulic retention times (HRT) of standard systems, making integration into wastewater (WW) grey infrastructure unfeasible. Industrial Phycology Ltd has developed a process that manipulates the metabolic plasticity of microalgae for WWT. Initial batch trials in a 27 m3 demonstration plant treating municipal tertiary WW achieved a final effluent of 0.27 ± 0.2 mg/L and 0.009 ± 0.003 mg/L phosphate and ammonium, respectively, in 12 h HRT. A continuous flow‐through system was retrofitted onto a small rural WWT site owned by South West Water for tertiary treatment. Phosphate and emerging contaminants (ECs) were monitored over 12 months at an average flow of 1.5–2.2 m3/h. Consistent phosphate removal was observed with a reduction in ECs within a HRT of 16.5 h. This demonstrates that the microalgae process can retrofitted as a green infrastructure option, delivering benefits vital to sustainable development.