Comparison of two different nickel oxide films for electrochemical reduction of imidacloprid

Light-powered biodegradation of Imidacloprid by Scenedesmus sp. TXH202001: Assessing complete removal, metabolic pathways, and toxicity verification

Imidacloprid (IMI) is used extensively as an insecticide and poses a significant risk to both the ecological environment and human health. Biological methods are currently gaining recognition among the different strategies tested for wastewater treatment. This study focused on evaluating a recently discovered green alga, Scenedesmus sp. TXH202001, isolated from a municipal wastewater treatment plant (WWTP), exhibited notable capacity for IMI removal. After an 18-day evaluation, medium IMI concentrations (50 and 100 mg/L) facilitated the growth of microalgae whereas low (5 and 20 mg/L) and high (150 mg/L) concentrations had no discernible impact. No statistically significant disparities were detected in Fv/Fm, Malonaldehyde or Superoxide dismutase across all concentrations, suggesting Scenedesmus sp. TXH202001 exhibited notable resilience and adaptability to IMI conditions. Most notably, Scenedesmus sp. TXH202001 successfully eliminated > 99 % of IMI within 18 days subjected to IMI concentrations as high as 150 mg/L, which was contingent on the environmental factor of illumination. Molecular docking was used to identify the chemical reaction sites between IMI and typical degrading enzyme CYP450. Furthermore, the study revealed that the primary path for IMI removal was biodegradation and verified that the toxicity of the degraded product was lower than parent IMI in Caenorhabditis elegans. The efficacy of Scenedesmus sp. TXH202001 in wastewater was exceptional, thereby validating its practical utility.

Plasmon Chemistry on Ag Nanostars: Experimental and Theoretical Raman/SERS Study of the Pesticide Thiacloprid Bond Cleavage by the Plasmon Deactivation Effect

Silver nanoparticles (AgNPs) were synthetized and employed in surface-enhanced Raman scattering measurements to study the chemical behavior when thiacloprid (Thia) interacts with the surface of Ag nanospheres (AgNSp) and Ag nanostars (AgNSt) upon excitation of the system with a 785 nm laser. Experimental results show that the deactivation of the localized surface plasmon resonance induces structural changes in Thia. When AgNSp are used, it is possible to observe a mesomeric effect in the cyanamide moiety. On the other hand, when AgNSt are employed, it promotes the cleavage of the methylene (-CH₂-) bridge in Thia to produce two molecular fragments. To support these results, theoretical calculations based on topological parameters described by the atoms in molecules theory, Laplacian of the electron density at the bond critical point (∇²ρ BCP), Laplacian bond order, and bond dissociation energies were made, confirming that the bond cleavage is centered at the -CH₂- bridge in Thia.

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.

One-step hydrothermal method for preparation of Ni/carbon thin film electrodes for efficient electroreduction of imidacloprid

A Ni/CTF was used as the cathode for electroreduction of imidacloprid, achieving a 92.1% removal efficiency for the electroreduction of imidacloprid.