Removal of Imidacloprid from Water by Microalgae Nannochloropsis sp. and Its Determination by a Validated RP-HPLC Method

The large-scale use of pesticides is one of the main causes of the dramatic degradation of our environment. Pesticides such as imidacloprid (IMID) have been linked to declines in bee health and toxicity to other beneficial insects. They pose a threat to human health due to their persistence in the environment and accumulation in the food chain. Therefore, it is essential to test possible environmentally-friendly solutions for their elimination. The present study evaluates the efficiency of microalgae Nannochloropsis sp. for the removal of IMID from synthetic wastewater. The influence of aeration, light, and the presence of UV radiation on the degradation of IMID were factors considered in the study. A rapid RP-HPLC method was developed and validated for the analysis and quantification of IMID in the context of bioremediation with microalgae. Nannochloropsis sp. removed 4.39 µg mL −1 from an initial content of 9.59 µg mL −1 (reaching approximately 50%) of IMID in the first 20 h. This study demonstrated that the removal of IMID by the marine microalgae Nannochloropsis sp. is both effective and light-dependent.