CO2-Inorganic Carbon Auto-Buffering System for Efficient Ammonium Reclamation Coupled with Valuable Biomass Production in a Euryhaline Microalga Tetraselmis subcordiformis

The performance of microalgae-based wastewater treatment processes for ammonium-N (NH4+-N) removal depends on the maintenance a favorable pH that is critical minimizing nitrogen escape in form free ammonia (NH3) and preventing high-NH3 or extreme-pH stress. This study developed CO2-inorganic carbon (CO2-IC) buffering system automatically stabilized with supply source efficient photosynthetic reclamation NH4+-N by euryhaline microalga Tetraselmis subcordiformis. soluble (NaHCO3) insoluble (CaCO3 MgCO3) ICs were compared this purpose. was well controlled range 6.5~8.5 CO2-IC system, which suitable growth T. (100 mg/L) almost completely removed three days, maximum rate 60.13 mg N/L/day minimal N 19.65% obtained CO2-NaHCO3 system. also restricted release extracellular organic matter stress conditions. enabled highest “normal” starch production fermentation, while CO2-CaCO3/MgCO3 facilitated high-amylose accumulation conducive to producing bio-based materials health-promoting ingredients. proteins accumulated subcordiformis good quality animal feeds.