Microalgae and sustainable wastewater treatment: a Review

Microalgae play important roles in the realisation of energy-efficient carbon-neutral wastewater treatment. This is achievable through coupling carbon capture with wastewater treatment and consequent biomass production. Unlike activated sludge, microalgal biomass is more of a resource than a waste. This paper presents a review on the use of microalgae in sustainable wastewater treatment including organic matter, nitrogen, phosphorus and heavy metals removal. The paper also focussed on microalgal cultivation systems and the potentials of using microalgal photosynthesis in satisfying bacterial oxygen requirements in hybrid algae-bacteria systems. The use of light-emitting diodes in microalgal photosynthesis and their prospects as promising light sources in hybrid algal wastewater treatment systems was also presented.