Amino-functionalized Magnetic Iron Nanoparticles As a Carrier for Laccase Enzyme and Its Potential to Degrade Chlorpyrifos in Contaminated Soil: Fate and Kinetics

摘要

The present study utilizes the covalent-crosslinking method to immobilize the laccase enzyme on magnetic iron nanoparticles and further assess its potential in degrading chlorpyrifos in pesticide spiked soil. The soil texture analysis revealed the presence of clay, silt and sand accounting to 7.1, 14.3, and 78.6, respectively. The degradation of chlorpyrifos in spiked soil using laccase enzyme immobilized magnetic iron nanoparticles was measured for 60 days in a batch process. The results revealed a gradual increase in degradation efficiency showing around 29.3, 43.8, 56.3, and 67.3 at the 20th, 30th, 40th, and 50th day of incubation. A maximum degradation of 83.6 was observed on the 60th day of incubation. Intermediate products 2,4-bis(1,1 dimethylethyl) phenol, 1,2 benzenedicarboxylic acid, bis(2-methyl propyl) ester and piperidine confirmed the degradation of chlorpyrifos in soil. The piperidine originated in the chromatogram between 20-40 days of incubation and diminished later. Chlorpyrifos degradation followed pseudo first-order kinetics with a R-2 of 0.96. Further, the nanoparticles showed no negative impact on soil bacterial population during the antibacterial assay. The study confirms the degradation of chlorpyrifos in contaminated soil using laccase-immobilized nanoparticles.