Impact of Elevated Ammonia Concentration on Scenedesmus dimorphus Growth in a Flat-Plate Photobioreactor

Uğuz S.

TURKISH JOURNAL OF AGRICULTURAL AND NATURAL SCIENCE, cilt.12, sa.2, ss.482-491, 2025 (TRDizin)

Özet

Animal feeding operations (AFOs) are significant sources of airborne pollutants, particularly ammonia (NH₃), which pose considerable environmental and health risks. In response to these challenges, photobioreactor (PBR) systems utilizing microalgae have emerged as a promising solution. These systems can effectively absorb and metabolize pollutants such as NH₃ and carbon dioxide (CO₂), thereby improving air quality while simultaneously producing valuable biomass. The present study specifically investigated the effects of elevated NH₃ concentrations on algal growth within PBRs. Ammonium chloride (NH₄Cl) was employed to simulate NH₃ concentrations typical of animal housing, specifically at a loading rate of 50 ppm (78 mg L⁻¹ d⁻¹ NH₄Cl). Over a 21- day experimental period, control tanks containing standard Bold's Basal Medium (BBM) were compared against those with NH₃ exposure. Results indicated that while normalized cell concentrations were highest in control tanks (1.79±0.09, p<0.01), the dry biomass was significantly greater in tanks subjected to the 50 ppm NH₃ loading rate (1.34±0.02, p<0.01). These findings suggest that microalgae possess a remarkable capacity to adapt to high NH₃ levels, highlighting their potential role in emission mitigation and sustainable biofuel production. The integration of PBR systems utilizing microalgae represents a viable strategy for addressing the environmental and health challenges posed by AFOs. By effectively utilizing pollutants such as NH₃, these systems not only enhance air quality but also contribute to the development of sustainable biofuels, thus supporting broader environmental sustainability goals.