Microalgae-based wastewater treatment:Mechanisms,challenges,recent advances,and future prospects

The rapid expansion of both the global economy and the human population has led to a shortage of water resources suitable for direct human consumption.As a result,water remediation will inexorably become the primary focus on a global scale.Microalgae can be grown in various types of wastewaters(WW).They have a high potential to remove contaminants from the effluents of industries and urban areas.This review focuses on recent advances on WW remediation through microalgae cultivation.Attention has already been paid to microalgae-based wastewater treatment(WWT)due to its low energy requirements,the strong ability of microalgae to thrive under diverse environmental conditions,and the potential to transform WW nutrients into high-value compounds.It turned out that microalgae-based WWT is an economical and sustainable solution.Moreover,different types of toxins are removed by microalgae through biosorption,bioaccumulation,and biodegradation processes.Examples are toxins from agricultural runoffs and textile and pharmaceutical industrial effluents.Microalgae have the potential to mitigate carbon dioxide and make use of the micronutrients that are present in the effluents.This review paper highlights the application of microalgae in WW remediation and the remediation of diverse types of pollutants commonly present in WW through different mechanisms,simultaneous resource recovery,and efficient microalgae-based co-culturing systems along with bottlenecks and prospects.

Bioplastic production in terms of life cycle assessment:A state-of-theart review

The current transition to sustainability and the circular economy can be viewed as a socio-technical response to environmental impacts and the need to enhance the overall performance of the linear production and consumption paradigm.The concept of biowaste refineries as a feasible alternative to petroleum refineries has gained popularity.Biowaste has become an important raw material source for developing bioproducts and biofuels.Therefore,effective environmental biowaste management systems for the production of bioproducts and biofuels are crucial and can be employed as pillars of a circular economy.Bioplastics,typically plastics manufactured from bio-based polymers,stand to contribute to more sustainable commercial plastic life cycles as part of a circular economy in which virgin polymers are made from renewable or recycled raw materials.Various frameworks and strategies are utilized to model and illustrate additional patterns in fossil fuel and bioplastic feedstock prices for various governments'long-term policies.This review paper highlights the harmful impacts of fossil-based plastic on the environment and human health,as well as the mass need for eco-friendly alternatives such as biodegradable bioplastics.Utilizing new types of bioplastics derived from renewable resources(e.g.,biowastes,agricultural wastes,or microalgae)and choosing the appropriate end-of-life option(e.g.,anaerobic digestion)may be the right direction to ensure the sustainability of bioplastic production.Clear regulation and financial incentives are still required to scale from niche polymers to large-scale bioplastic market applications with a truly sustainable impact.