Microalgae for Environmental Cleanup: A Holistic and Sustainable Approach for Pollution Management

Microalgae play a significant role in the bioremediation of various types of environmental pollutants, including heavy metals, organic compounds, pesticides, and pharmaceuticals. Algal bioremediation offers several advantages, including economic efficiency, resilience, and the production of valuable products. This chapter covers the principles of phycoremediation methods and explores the underlying mechanisms. It also demonstrates the involvement of algae in reducing the pollution from agricultural sources, industry, and urban areas. Nowadays, microalgae are considered one of the excellent tools in the bioremediation process due to their ease of cultivation, diverse metabolic activity, green, and environmental adaptability as a promising alternative technique when compared to the conventional methods. The excess nutrients present in the contaminated water bodies, such as nitrogen, phosphorus, heavy metals, and organic compounds, can be effectively removed by photosynthetic microalgae. Bioadsorption, bio-uptake, biodegradation, and photodegradation are the major processes involved in this context. The effectiveness of algal bioremediation depends on numerous interrelated factors, such as pH, temperature, light intensity, and the nature of the pollutant and its concentration. Even though the algae play a major role in pollutant reduction, there are several hurdles, like slow growth rate, huge investment required for production, heavy contamination, stability loss, and complex recovery process, which are the major issues still facing in the development of industrial scaling processes, and hence, fine-tuning is much required for effective treatment. The integration of existing treatment methods and genetic engineering is the two pivotal methods that improve the pollution tolerance with greater potential. This chapter highlights the importance of algae to mitigate the wide range of environmental issues occurring in the current scenario, such as water and soil pollution, and other challenges in the environment. Also, phytoremediation and microbiological treatments are combined with algal bioremediation for better results. This field addresses the challenges and leverages genetic engineering, which helps in the development of industrial applications. Overall, this chapter encompasses the principles, practical use, and future prospects of phycoremediation.