Work

Algal growth potential based nitrogen and phosphorus criteria for bloom control

Year: 2025

Type: article

Abstract: High concentrations of nitrogen (N) and phosphorus (P) in aquatic systems can readily induce eutrophication, posing significant ecological and human health risks. Establishing scientifically sound N and P water quality criteria is therefore essential for effective water resource management and algal bloom mitigation. Current approaches to establishing lake nutrient criteria primarily rely on determining reference conditions, a method that faces practical limitations due to the pervasive pollution affecting most water bodies. To address this challenge, this study introduces an innovative methodology for deriving N and P criteria based on algal growth potential analysis, which establishes the theoretical minimum nutrient thresholds required for bloom formation.We selected and cultured twenty-three dominant algal species identified from documented bloom events to assess their growth potential. Under optimized cultivation conditions, we determined the maximum N and P yield coefficients for each species, from which we subsequently calculated species-specific N and P criteria based on predetermined bloom thresholds. Using species sensitivity distribution (SSD) analysis, we derived protective nutrient criteria corresponding to the 5th percentile hazard concentration: 0.204 mg/L for N and 0.006 mg/L for P. These values are notably more stringent than those established in European and American guidelines, as well as previous Chinese studies. This study thus establishes a novel scientific framework for developing water quality standards, particularly applicable to urban lakes receiving reclaimed water with high N and P concentrations. • The new N and P criteria deduction method is based on algal growth potential • Species sensitivity distribution model was used for criteria extrapolation • 23 dominant algal species were adopted according to the bloom outbreak data • Different species have dramatically distinct yield coefficients of N and P • The derived N and P criteria are 0.204 mg/L and 0.006 mg/L in this study

Source: Water Cycle

DOI: 10.1016/j.watcyc.2025.10.004

Authors: Jun-Han Liu, Yun Lu, Guo-Hua Dao, Sheng-Nan Wang, Ke-Ying Song, Hong-Ying Hu