Toxicity analysis and degradation studies of chlorpyrifos in agricultural wastewater using magnesium ferrite-gelatin nanocomposites

Abstract

In addressing the pressing environmental challenge of Chlorpyrifos (CPF) contamination in agricultural wastewater, we successfully synthesized a novel organic/inorganic bio-adsorbent known as Magnesium-Ferrite Gelatin (MFGEL) nanocomposites using a co-precipitation method. To thoroughly investigate this issue, we collected agricultural wastewater from various locations near Coimbatore, Tamil Nadu, and employed the QuEChERS method followed by High-Performance Liquid Chromatography (HPLC) analysis. Our results confirmed that CPF concentrations exceeded the permissible limits established by the EU and USEPA. From our calibration curve, we determined the limit of detection (LOD) to be 0.0225 mg/L and the limit of quantification (LOQ) to be 0.0683 mg/L, demonstrating the sensitivity of our method. Batch studies on the MFGEL nanocomposites revealed a removal efficiency of 99 % for CPF under optimized conditions. Elemental analysis using Energy Dispersive X-ray Spectroscopy (EDX) provided clear evidence of effective CPF adsorption, identifying the presence of chlorine, phosphorus, and sulfur within the MFGEL structure. Our characterization studies showed a significant reduction in crystallinity, confirming the formation of an amorphous structure due to gelatin’s interference in MFGEL. The Scanning Electron Microscopy (SEM) analysis displayed a rough and highly porous surface with irregular shapes, highlighting the effectiveness of the adsorption process. Furthermore, Brunauer-Emmett-Teller (BET) analysis indicated that MFGEL possesses a mesoporous structure with a surface area of 30.652 m2/g. The results from Fourier-transform infrared (FTIR) and Raman spectroscopy analyses further revealed that gelatin in MFGEL introduces functional groups (such as O–H, N–H, and amide groups) that significantly enhance interaction with CPF. In addition, the ferrite component facilitates additional binding through surface complexation. Our reusability studies demonstrate that MFGEL maintains outstanding performance, retaining an adsorption efficiency of 98.7 % to 87 % and a regeneration efficiency of 96 % to 81 % over five cycles. This emphasizes the remarkable effectiveness and robustness of the MFGEL nanocomposite for CPF remediation in agricultural wastewater.