New and innovative microwave-assisted technology for synthesis of guar gum-grafted acrylamide hydrogel superabsorbent for the removal of acid red 8 dye from industrial wastewater

Abstract The goal of this study is to develop a new effective guar gum-grafted acrylamide hydrogel for wastewater treatment, abbreviated as (guar gum-g-acrylamide). For the non-biodegradable and hazardous synthetic acid red 8, produced gum-g-acrylamide promising thermally stable adsorbent. Microwave-aided technique, ammonium persulfate initiator, N , ?-methylene-bis-acrylamide cross-linker are used make comprising natural polysaccharides gum grafted by poly acrylamide. Fourier transformer infrared (FTIR) spectra scanning electron microscopy (SEM) demonstrate that varied percentages successfully graft backbone gum. When grafting percentage raised, hydrogel’s maximum adsorption capacity (qe) increases. At pH 1 dye solution, 18 mg.g ?1 at 9; qe decreased up 8 . 0.5 g.L hydrogel, has low removal (34%), but when dosage increased increases 90%. initial AR8 concentration was from 50 300 mg.L reduced 20% adsorbed quantity 17 44 both parameters became limited above concentration. Other ideal conditions include 60 min contact time, 150 revolutions per minute (rpm), temperature 20 degrees Celsius. kinetic pseudo-second order, assuming electrostatic interaction between negatively charged molecules positively hydrogel-functional group. values fit Langmuir isotherm, with q max 54.054 decreases rises, indicating physisorbed on pores, °C. exothermic spontaneity were confirmed negative heat (? H ° ads. ) standard Gibbs free energy G ). reusability validated after three cycles desorption surface in alkaline solution.