Eco-friendly products for sorption of fenamiphos, imidacloprid, and oxamyl pesticides from water and their detection by UV/VIS spectrophotometry

The present study evaluates the efficiency of the dry biomass of the microalgae Spirogyra porticalis and Nannochloropsis oculata for the removal of fenamiphos, imidacloprid, and oxamyl pesticides from water. The influence of incubation time, pesticide concentration, and algal biomass concentration on the degradation of pesticides were considered in the study. A rapid UV-Vis spectrophotometry method was developed and validated for the analysis and quantification of pesticides in the context of bioremediation with microalgae. The optimum conditions were obtained at 15 min, 50 mg/L pesticide concentration and 900 mg/L algal biomass with the response of 67.27% and 68.67 for fenamiphos by S. porticalis and N. oculata, respectively. For Imidacloprid, the optimum conditions were obtained at 15 min, 50 mg/L pesticide concentration and 900 mg/L algal biomass with the response of 28.20% and 35.55 for fenamiphos by S. porticalis and N. oculata, respectively. With the same, previse conditions the response of 65.71 and 81.31% for oxamyl by S. porticalis and N. oculata, respectively. This study confirmed that removing pesticides by the microalgae S. porticalis and N. oculata are both active and biomass of algae dependent. Consequently, these algae biomass exhibited a potential reduction of pesticides in contaminated water samples.​