Microalgae an ecofriendly and sustainable wastewater treatment option: biomass application in biofuel and bio-fertilizer production. A review

摘要

Rapidly growing industrialization and depletion of non-renewable fossil fuel have led to finding alternative viable renewable resources to meet the growing energy demand with less carbon dioxide generation. The modern world energy strategy is based on cost-effective and green alternatives and microalgae cultivation has the potential to meet these criteria. Microalgae have been identified as a promising and sustainable alternative for treating wastewaters along with the production of valuable products. Microalgae have a short lifespan, high growth rate, and high CO_2 utilization efficiency. They can produce biomass using nutrients in wastewater. At present, the technology and cost are the main factors that limit the application of microalgae at the industrial scale, which needs an ideal downstream process to minimize the production cost. The simultaneous use of microalgae for wastewater treatment and biofuel production has made these challenges practicable and economically viable. Microalgae efficiency for ammonia, phosphorus, and heavy metal removal along with biofuel and biofertilizer production is reviewed. Recent advances in cultivation of microalgae in wastewater, the response of microalgae to different stresses, and their effects on the quality and quantity of high-value products were investigated. The prospects for future research dealing with wastewater treatment and biofuel production on downstream processing are also highlighted.