Metal ferrite supported composite hydrogel: synthesis, characterization and dye adsorption

In this thesis study, metal ferrite (CdFe2O4) doped hybrid polymeric hydrogel was synthesized in three steps. In the first step of the study, 2-Acrylamido-2-methyl-1-propanosulphonic acid/Itaconic acid (AMPS/IA) monomers; The hydrogel was synthesized by radical polymerization using N,N Methylene bisacrylamide (MBAA) as crosslinker and Potassium persulphate (KPS) as initiator. In the second step, the synthesized hydrogel was modified in CdCl2.2.5H2O/FeCl3.6H2O aqueous solution and then CdFe2O4 doped hydrogels were prepared by co-precipitation method. In the third step, detailed characterization of the synthesized hybrid polymeric hydrogels was carried out by FESEM-EDX, STEM, FTIR, XRD, TG/DTG, DLS, BET, VSM-DG, pHpzc, Zeta potential techniques. As a result of the characterization studies, it was observed that the prepared hybrid hydrogel had magnetic properties and thermal stability, and its surface properties were suitable for adsorption. In the last step, adsorption studies of Malachite green oxalate (MGO) dye, which is widely used in the industry, from aqueous solution were performed. The adsorption conditions were optimized by investigating the effects of adsorbent amount (10-40 mg/50 mL), pH (3-11), time (5-240 min), dye initial concentration (12.50-2250 ppm) and temperature (25-60 oC) on adsorption. As a result of adsorption studies, it was observed that quantitative removal was provided (96%) even at 10 mg/50 mL adsorbent dose in a wide pH range. In studies conducted at different temperatures at 100 ppm and 500 ppm, it was determined that MGO removal was not affected by temperature and the developed adsorbent had a very high removal capacity (2500 mg/g). In addition, from the reusability studies carried out 5 times, it was understood that the hybrid polymeric adsorbent maintained its removal efficiency for MGO dye. From the kinetic and isotherm results, it was determined that the adsorption of MGO onto CdFe2O4 was more suitable for the pseudo-second-order kinetic model and the Langmuir isotherm model.