A multifunctional cellulose- and starch-based composite hydrogel with iron-modified biochar particles for enhancing...

Area of Science:

• Biotechnology
• Materials Science
• Environmental Science

Background:

• Microalgae cultivation is crucial for biofuels and bioproducts.
• Enhancing microalgae growth requires sustainable and effective additives.
• Polysaccharide-based hydrogels offer potential for agricultural and biotechnological applications.

Purpose of the Study:

• To fabricate and characterize a multifunctional polysaccharide-based hydrogel.
• To evaluate the hydrogel's efficacy in enhancing microalgae growth.
• To determine the optimal hydrogel concentration for microalgae cultivation.

Main Methods:

• Hydrogel synthesis using carboxymethyl cellulose (CMC), arrowroot starch, iron-modified biochar, oxidized sucrose, and glycerol.
• Optimization of hydrogel formulation based on swelling ratio, BET surface area, and electrical conductivity.
• Assessment of microalgae growth (yield and cell concentration) with varying hydrogel concentrations in Bold basal medium.

Main Results:

• The optimal hydrogel formula was determined with specific ratios of starch, CMC, biochar, oxidized sucrose, and glycerol.
• A hydrogel concentration of 2.5 g/L significantly increased algal yield by 65.7% and cell concentration by 92.2%.
• Higher hydrogel concentration (12.5 g/L) led to a 67.8% decrease in algal yield due to oxidative injury, and altered microalgae elemental composition.

Conclusions:

• The developed polysaccharide hydrogel is a promising additive for enhancing microalgae growth and biomass production.
• Careful optimization of hydrogel concentration is essential to avoid negative impacts on microalgae.
• The hydrogel influences microalgae's nutrient content, with increased nitrogen and decreased carbon, hydrogen, and sulfur.