However, the cost of algal growth and biomass harvesting is limiting the technology at large scale.
It has been more apparent that High Rate Algal Ponds (HRAP) and microalgal biofilms [2] are allowing recovery of nutrients such as nitrate and phosphate from municipal wastewater [3] as well as toxic waste removal [4]. In this process, microalgae use the end products of bacterial metabolism (for example CO2 and ammonia) and in turn, supply aerobic bacteria with the oxygen required for the degradation of organic compounds..