Short-term nutrient removal efficiency and photosynthetic performance of Ulva pseudorotundata (Chlorophyta): potential use for Integrated Multi-Trophic Aquaculture (IMTA)

• Published in: Journal of applied phycology Vol. 35; no. 1; pp. 233 - 250
• Main Authors: Massocato, Thaís Fávero, Robles-Carnero, Victor, Vega, Julia, Bastos, Eduardo, Avilés, Antonio, Bonomi-Barufi, José, Rörig, Leonardo Rubi, Figueroa, Félix López
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2023; Springer Nature B.V
• Subjects: Aeration; Aeration tanks; Algae; Ammonium; Ammonium compounds; Ammonium nitrogen; Aquaculture; Biofiltration; Biomass; Biomedical and Life Sciences; Biotechnology; Carbohydrates; Chlorophyll; Chlorophyll a; Ecology; Efficiency; Effluents; Energy; Fluorimetry; Fluorometry; Freshwater & Marine Ecology; Laboratories; Life Sciences; Metabolism; Nitrogen; Nutrient concentrations; Nutrient removal; Parameters; Photosynthesis; Physiology; Plant Physiology; Plant Sciences; Polyculture (aquaculture); Pulse amplitude modulation; Removal; Solar radiation; Stocking density; Tanks; Chlorophyll; Algal biomass; fluorometry; Chlorophyta; Biofiltration; Nitrogen; Photosynthesis; Aquaculture
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-022-02888-8

Short-term N-NH 4 + and N-NO 3 − removal by Ulva pseudorotundata under different initial nutrient concentrations and biomass stocking densities were investigated, monitoring in parallel photosynthetic parameters obtained by Pulse-Amplitude-Modulation (PAM) fluorometry of chlorophyll- a and evaluating biomass characteristics (CHN, proteins, carbohydrates). The results showed that U. pseudorotundata cultivated under solar radiation in a land-based outdoor pilot scale system was efficient in removing N-NH 4 + and N-NO 3 − even in concentrations as high as 500 µmol L –1 ensuring complete water remediation in a period of 24 h and in all experimental conditions tested, however differences were observed depending on the stocking density and type of N-source. Treatments with N-NH 4 + showed faster N removal than those with N-NO 3 − , whilst treatments with N-NO 3 − required more photosynthetic energy. Part of the ammonium removed in the respective treatments may have been volatilized as a combined effect of the pH increase related to photosynthesis and aeration in the tanks. The results presented here establish the fundamental parameters for the use of U. pseudorotundata as a biofiltering organism for effluents with high concentrations of N-NH 4 + and N-NO 3 − .