Microalgae production as a biofuel feedstock: risks and challenges

From a sustainability perspective, the potential risks associated with microalgae production for biofuel extraction will be investigated in this paper, including the environmental, economic, social and cultural dimensions. Environmentally, four main concerns are mapped out: first, there are potential water safety risks, such as water resource abuse, water pollution and groundwater recharge deficiency; second, unreasonable construction will lead to land-use overexpansion, land pollution and service expectancy reduction; third, microalgae production may exert a detrimental effect on the local ecosystem, causing algal blooms and biological invasion; finally, microalgae might emit unexpected greenhouse gases [nitrogen oxides (NO x ), methane (CH4)] and ammonia (NH3). From an economic risk standpoint, microalgae production requires an overwhelming investment due to the expensive start-up and operation. Socially, contaminant discharge will threaten the health of local animals and people. Moreover, the safety effects of genetically modified algae may not be immediately apparent or known. In addition, over time, microalgae may become a medium for mosquitoes to spread disease. From a cultural point of view, it requires time for people in developing countries to adapt algal oil to their daily life as an alternative to conventional fossil fuels. Furthermore, personnel changes in the workforce may harm existing cultural structures, and landscape aesthetics may be affected by system construction. Taking the above challenges into consideration, efficient government policies, proactive company behaviours and positive public participation will play an important role in minimising or even eliminating these potential risks.