New Hybrid ZIF-8/NC-PU and NC-PU Gel Composites for the Effective Removal of Cationic and Anionic Dye from Aqueous Solution: Process Optimization

New hybrid metal organic framework based polymer nanocomposite (ZIF-8/NC-PU) and interpenetrating polymer gel nanocomposites (NC-PU) were prepared for the adsorption of cationic (Rh-B) and anionic (IC) dyes from aqueous solution. The characterisation of the ZIF-8 based composites and gel composites is carried out using FT-IR and SEM analysis to investigate the chemical composition and morphology of the sample. Moringa oleifera seed pod based nanocellulose (5 wt%) is used as the filler in NC-PU gel composites and ZIF-8/NC-PU MOF composites. The optimal level of the most significant identified variables affecting the adsorption process were determined by the response surface methodology (RSM) using Plackett–Burman and Box–Behnken design. Adsorption capacity increased with the increase in dosage of the adsorbent, pH and initial dye concentration. Plackett–Burman was performed for the experiments involving the dyes Rh-B and Indigo carmine dyes. It gave 12 experiments in each trials and resulted in 3 significant parameters. Box–Behnken was further used to determine the optimum parameters for the adsorption keeping PU weight percentage as 3. The percentage uptake predicted by the model is in good agreement with the experimental values. The findings assume that the adsorbents could be used effectively as highly efficient adsorbents for the removal of multiple dyes from wastewater.