Microalgae-based carbon farming and biofertilizer for sustainable agriculture

Overview

This solution leverages microalgae as a multifunctional tool for advancing circular economy goals in agriculture. Microalgae are cultivated in wastewater, where they absorb excess nutrients such as nitrates and phosphates, simultaneously improving water quality and producing nutrient-rich biomass. This biomass, containing protein, starch, and lipids, can be applied to farmland as a biofertilizer, rehabilitating soil organic carbon content and promoting long-term soil fertility. By replacing synthetic fertilizers, this approach reduces nitrogen and phosphorus runoff into surface and groundwater, addressing a major environmental concern while supporting sustainable farming practices.

Technical specifications

Key features:

• Microalgae cultivation in wastewater achieves nutrient removal, with nitrate levels reaching detection limits during growth
• Biomass composition: approximately 35% protein, 32% starch, and 32% lipid content
• Carbon sequestration through atmospheric CO₂ fixation, yielding substantial biomass gain (0.80 g/L)
• Algal cells serve as a source of neutral fatty acids, validated through TLC, GC, and GC-MS analysis
• Potential to rehabilitate net soil organic carbon and improve soil aggregate stability, humidity, and porosity
• Application of native and non-native algae isolates or consortia to promote soil microbiome health and organic carbon cycling

Technology readiness level

The technology has been validated at the laboratory scale, with demonstrated algae growth in wastewater, quantitative biomass composition analysis, and lipid characterization. Ongoing experiments are evaluating algal biomass as a biofertilizer for carbon sequestration and soil rehabilitation. Future validation includes greenhouse trials to monitor plant growth, outdoor bioreactor development for mass algae production, and field studies on agricultural soil. The research is positioned to transition from controlled laboratory conditions to pilot-scale outdoor cultivation and field application.