Use of microalgae for treating municipal wastewater reverse osmosis concentrate and resource recovery

Abstract

<p>In recent years, microalgae-based wastewater treatment technology has emerged as an alternative which may offer a cost-effective and eco-friendly solution for ROC management. Microalgae can potentially remove nutrients and organic matter from municipal ROC while enabling water reclamation and adding value to the treatment process by resource recovery via biomass production. However, no detailed information is available on (1) algal treatment of municipal ROCs with different characteristics (e.g., total dissolved solids (TDS), alkalinity, pH), (2) the contribution of each possible nutrient removal pathway, (3) the physical and chemical response of alginate immobilised algae under conditions reflective of the characteristics of ROC (particularly the combined effect of the main stressors such as pH and salinity), (4) recovering resources via the identification of cost-effective and practical harvesting methods, and (5) comparison of performance of different algal species in a system of ROC treatment combined with biomethane production under stress conditions (e.g., high TDS levels). Thus, this study was aimed at filling the identified research gaps and hence gaining more insights into the technological feasibility of the treatment of ROC using microalgae, as a potentially sustainable solution for ROC management.</p>