Long-term missing role of small colloids and nanoparticles on the loading and speciation of phosphorus in catfish aquaculture ponds in west Alabama

• Published in: Chemosphere (Oxford) 2023-11, Vol.340, p.139906-139906, Article 139906
• Main Authors: Hamid, Ansley K., Wilson, Alan E., Gladfelter, Matthew F., Knappenberger, Thorsten J., Wang, Dengjun
• Format: Article
• Language: English
• Subjects: Catfish aquaculture ponds; Harmful algal blooms; Particle size separation; Phosphorus; Phosphorus loading and speciation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2023.139906

Increasing loading of phosphorus (P) into freshwater systems is deemed as one of the key drivers triggering harmful algal blooms (HABs). However, conventional water quality monitoring of P normally uses the operational cutoff (e.g., 450-nm filter membrane) to separate particulate and dissolved phases (entities passing through the 450-nm membrane are regarded as dissolved phase), which completely neglects the roles of small colloids (450–100 nm) and nanoparticles (100–1 nm). Herein, a new particle size separation approach was used to separate water samples collected from catfish aquaculture ponds in west Alabama into six size fractions: large particles (>1000 nm), large colloids (1000–450 nm), small colloids (450–100 nm), large nanoparticles (100–50 nm), small nanoparticles (50–1 nm), and the truly dissolved phase (