Synthesis of Novel AgNPs/Polyamide Composite as Filtration Membranes for Removal of Trihalomethanes in Water Sample by in Tube Microextraction with GC-MS/ P&T

A new, rapid, simple and effective removal procedure using in tube micro extraction method (in tube-ME) based on AgNPs /polyamide composite as adsorbent and combined with GC-Mas detector as well as purge and trap technique (GC-MS/P&T) has been developed for the removal of trihalomethanes (THMs). In this study, AgNPs/polyamide composite was prepared based on reducing silver ions on the surface of polyamide without using any reducing agent. The synthesis process was carried out in water containing silver nitrate using the inherently reducing and the stabilizing properties of polyamide chains. Silver ions penetrate into the intermolecular chains of polyamide and reduce to Ag and form AgNPs. The synthesized AgNPs /polyamide composite was characterized using fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and SEM-energy-dispersive x-ray spectroscopy (SEM-EDS). In this extraction technique, AgNPs/polyamide composite was packed into a Teflon syringe and employed as an extraction device for the removal of THMs including chloroform (CHCl3), bromo dichloromethane (CHBrCl2), dibromochloromethane (CHBr2Cl) and bromoform (CHBr3) from water samples. The effects of various experimental parameters such as the pH of the solution, the adsorbent dosage and the effect of different cycle time periods of the samples in the teflon syringe were investigated and optimized. After optimization, the best experimental conditions were set as initial THMs concentration 10 μg L−1, adsorbent amount 7.0 mg and cycle time periods of 14 , sample solution pH:7. The equilibrium data were fitted to different isotherm models and the results revealed the suitability of the Langmuir model. The maximum sorption capacity calculated from the Langmuir model was 218 mg g−1 for THMs. Kinetic data revealed that the adsorption process followed a pseudo-second-order model. The removal efficiency of in waters samples by using AgNPs/polyamide composite was in the range of 93.5-100.2%. Strategy used for preparation AgNPs/polyamide composite and also general picture of the steps microextraction method used in the study, shown in graphical abstract.