Combatting cyanobacteria: unraveling the potency of 316L-Cu stainless steel in inhibiting Microcystis aeruginosa growth

Harmful algal blooms, particularly those of Microcystis aeruginosa, present significant ecological and health risks. To address this issue, this study utilized a custom static algal growth assessment apparatus to investigate the anti-algal performance of a copper-alloyed 316L stainless steel (SS), named 316L-Cu SS. This material was compared with traditional 316L SS, which is widely utilized in freshwater systems for its corrosion resistance. Algal growth dynamics were monitored through optical density (OD) and chlorophyll A concentration measurements. Notably, 316L-Cu SS exhibited superior inhibitory effects on Microcystis aeruginosa growth compared to 316L SS and control groups. Inductively coupled plasma mass spectrometry (ICP-MS) confirmed that the copper ion release from 316L-Cu SS played a critical role in this algal suppression, which interfered with photosynthesis, induced oxidative stress, and damaged algal cell membranes. In contrast, other metal ions (Ni, Cr, Fe) had a negligible impact on algal growth. The study highlights 316L-Cu SS as a promising material for mitigating harmful algal blooms, thereby offering potential benefits for both aquatic ecosystem conservation and public health protection.