Novel membrane adsorbents prepared by waste fibers of mechanized carpet for Persian Orange X removal

- Membrane adsorbents were prepared as novel adsorbents via phase separation technique.
- Best membrane adsorbent was chosen with pore size of 28-32 nm and proper distribution.
- NH2OH.HCl concentration and reaction time were significantly influenced on process.
- Kinetic and thermodynamic properties were fitted by second-order and Langmuir model.
- Textile dyeing wastewater in Kashan Textile Co. was treated with 95% removal.

A large amount of acrylic fibers or fuzzes are wasted in carpet industries and environmentalists have become concerned about this issue. In this study, it was tried to prepare a novel ecofriendly adsorbent with amidoxime functional groups by waste acrylic fibers. They were used for disposing an azoic acid dye (Persian Orange X) from textile effluents in Kashan Textile Company. These membrane adsorbents were synthesized by phase separation process followed by amidoximation. Taguchi experimental design was utilized to optimize amidoximation process and dye removal. Based on this analysis, the concentration of hydroxylamine hydrochloride (negatively) and reaction time (positively) were the most significant factors that influenced on the responses. The membrane adsorbents with 28-32 nm and an appropriate distribution were selected as an optimum adsorbent. Kinetics data and adsorption isotherm were fitted by pseudo-second-order kinetic model and Langmuir isotherm, respectively. The values of activation parameters such as free energy (ΔG: −367.668∼-1374.260 kJ/mol), enthalpy (ΔH: 553.98 kJ/mol) and entropy (ΔS: 32.23 J/molK) were determined, respectively, indicating that the adsorption was spontaneous, favorable and endothermic process in nature. Moreover, the membrane adsorbents were stable and easily collected. The adsorption capacity was about >95%.