Synergistic influence of iodine and hydrogen peroxide towards the degradation of harmful algal bloom of Microcystis aeruginosa

• Published in: Environmental research 2023-11, Vol.237, p.116926-116926, Article 116926
• Main Authors: Ajayan, K.V, Chaithra, P.J, Sridharan, Kishore, Sruthi, P, Harikrishnan, E, Harilal, C.C
• Format: Article
• Language: English
• Subjects: agricultural runoff; algae; algal blooms; Cell damage; Chlorophyll fluorescence; cyanobacterial toxins; Hydrogen peroxide; Iodine; Microcystis; Microcystis aeruginosa; phycocyanin; synergism; temperature
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2023.116926

Cyanobacterial blooming due to the influence of temperature and increased nutrients in ponds/lakes aided by the runoff from agricultural lands, is a serious environmental issue. The presence of cyanotoxins in water may poison the health of aquatic organisms, animals, and humans. In this study, we focus on chemical assisted degradation of Microcystis aeruginosa– an alga that is of special relevance owing to its consistent blooming, especially in tropical regions. The study aims to ascertain the individual iodine (I) and hydrogen peroxide (H2O2) and their combination (hereinafter referred to as IH) effects on the degradation of Microcystis aeruginosa. As expected, the collected pond water revealed the presence of metal ions viz., Ni, Zn, Pb, Cu and Mn, which enriched the blooming of M. aeruginosa. Interestingly, a complete rupture of the cells – pigment loss, biochemical degradation and oxidative damage–was observed by the IH solution after exposure for ∼9 h under ambient conditions. In comparison to control (original water without chemicals), the addition IH completely eliminated the pigments phycocyanin (99.5%) and allophycocyanin (98%), and degraded ∼81% and 91% of carbohydrates and proteins, respectively due to the synergistic action of I and H. Superior degradation of algae through a simple and eco-friendly approach presented in this study could be explored more effectively towards its large-scale applicability. [Display omitted] •Zn, Cu and Mn typically promote blooming of M. aeruginosa.•Iodine and H2O2 are employed to treatM. aeruginosawater sample.•Iodine is found to target the degradation of carbohydrate and protein content.•Iodine and H2O2 (IH) solution exhibited faster degradation than individual chemicals.•IH proved to an eco-friendly chemical agent to inhibit M. aeruginosa blooming.