Carbon dioxide sequestration, bioremediation, and production of value-added products from freshwater filamentous green algae
摘要
Four different species of filamentous green algae were cultivated in separate ponds for 21 days to examine their biomass productivity, carbon dioxide sequestration potential, nutrient removal ability, and the generation of value-added products from the derived biomass. Among the tested algae, Spirogyra sahnii exhibited the highest dry biomass (1.30 ± 0.15 kg), resulting in a carbon sequestration potential of 0.80 ± 0.15 g CO2/m2/d. Harvested dry biomass was converted into pulp (including with additives) for the generation of possible value-added products, especially filter paper. Various characteristics of paper derived from algal pulp, including its tensile strength, flexibility, biodegradability, water resistance, softness, weight, porosity, water absorption capacity, and water retention capability, were measured to assess the quality of value-added products. The paper made from the pulp of Cladophora glomerata exhibited properties similar to those of commercially available filter papers. The obtained paper was also used for writing, and it showed comparable performance with the augmented paper derived from wood pulp. To enhance the mechanical strength and brightness of the algal papers, certain chemical additives, including starch, sulphur, and glycerol, were mixed with pulp in varying proportions. Making packaging materials and embossed religious objects from algal pulp has also been demonstrated. Overall, this study concludes that filamentous freshwater algae are a promising agent for sequestering carbon dioxide, and their biomass is a potential material for generating local income through the production of value-added products, which will also contribute to achieving sustainable development goals (SDGs) in an eco-friendly and cost-effective manner.