synthesis of magnetic polyvinylchloride/polypyrrole nanocomposite; investigating of adsorptive removal of cationic dye of crystal violet from aqueous solutions

Abstract: one of the most important directions for environmental remediation is the effective removal of dyes and toxic heavy metal ions from water sources using newly fabricated nanoadsorbents [1]. polypyrrole-based (ppy) composites are promising candidates for water and wastewater treatment [2]. the most suitable method among pollutant removal methods is adsorption due to process simplicity, high efficiency and low cost [3]. herein, nanocomposite pvc/fe3o4/ppy in order to removal of dye from aqueous solutions by a simple and low cost method was synthesized. first pvc/fe3o4 was synthesized via co-precipitation method and then the monomer of pyrrole was polymerized onto it [4]. the properties of the prepared nanocomposite were characterized by the x-ray diffraction (xrd), diffuse reflectance spectroscopy (drs), vibrating sample magnetometer (vsm), fourier transform infrared (ft-ir) and field emission scanning electron microscopy (fe-sem) techniques. in order to obtaining the optimum conditions for achieving maximum adsorption capacity, the effect of various parameters such as ph, contact time, pollutant concentration, adsorbent dosage, temperature, etc. were studied. the results obtained discovered that percentage removal of dye increases with ph increasing up to ph=10. it was found that the percentage of crystal violet (cv) dye removal at ph of 10 with 50.0 mg of adsorbent, initial dye concentration of 50.0 mg l-1, in contact time of 40 minutes was above 93%. according to the carried out kinetics and isotherm investigations, it was found that the adsorption process are well described by the pseudo-second-order synthetic model (r2 = 0.998) and the langmuir isotherm model (r2=0.992). based on dubinin-radushkevich model, the adsorption of crystal violet on pvc/fe3o4/ppy was temperature dependent, spontaneous and endothermic (δs and δh are 260.0 j mol−1k−1 and 72.0 kj mol−1, respectively). the reusability of the adsorption-desorption cycle of pvc/fe3o4/ppy was studied to 3 cycles, and it was found that cv dye removal efficiency was unchanged after at least 3 cycles.