The proliferation of harmful algal blooms (HAB) in freshwater ecosystem has increased along with the eutrophication as a result of excessive nutrient supply. The traditional chemical algaecides, though having the ability to reduce the bloom intensity are often associated with secondary pollution and disruptive to the ecological balance. In order to close the gap, Chloroclear was created, a lipid bound chitosan-zinc oxide (ZnO) nanocomposite film, which can oxidize chlorophyll-a and destroy algal cells under sunlight. The study goals will encompass determining the most effective dosage of the ZnO, establishing the dynamics of cell destruction of algae over time, comparing samples treated and untreated, and clarifying future molecular interaction possibilities by performing in-silico studies. The fabrication of films with 100 mg, 200 mg, and 300 mg of ZnO was made by extracting chitosan out of crab shells combined with soy lecithin and ZnO nanoparticles dispersed 13x13 cm at 1 cm thickness. Treatments were applied on 500 mL eutrophic water with a 5 g of algal biomass exposed under sun for photocatalytic process. The degradation of chlorophyll-a was measured through UV-Vis spectrophotometry, cell non-viability of the algae was measured through the hemocytometer. The most suitable formulation was studied at an exposure period of 24, 48, and 72 hours. To determine the interactions between ZnO clusters, chlorophyll-a and phosphatidylcholine, complementary in-silico docking studies were carried out. The highest mean chlorophyll-a degradation was observed in 300-mg ZnO film at 49.855%. The mortality of algal cells rose gradually up to 86.87% at 24 and 99.07% at 72 hours. Furthermore, there was a significant cellular disruption in treated specimens in comparison to untreated controls. Overall, Chloroclear has demonstrated superior photocatalytic mechanism that cause chlorophyll oxidation and algae cell disruption, which indicate its suitability as an efficient method for algal growth control.
Vargas et al. (Fri,) studied this question.