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

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