lignocellulose nanofiber media for the enhanced removal of copper from aqueous solutions

Nowadays, the entry of heavy metals entry into aqueous environments has jeopardized the health of human societies. the experiment was conducted in discontinuous conditions, and the study focused on examining the effect of five parameters including initial concentration, temperature, contact time, ph, and adsorbent dose on the adsorption of cu heavy metals. in addition, the twoparameter models of langmuir, freundlich, temkin, and dubininradushkevich were studied and compared to evaluate isothermal absorption. the highest correlation coefficients were obtained for freundlich (0.969) and dubininradushkevich (0.9603) models. finally, thermodynamic parameters such as enthalpy and entropy changes and gibbsfree energy were calculated as well. the ph parameters, adsorption dose, contact time, temperature, and initial cu concentrations in the discontinuous system had a statistically significant effect on the adsorption process. the results showed that the maximum efficiency of cu adsorption by lignocellulose nanofiber (lcnf) occurred at the ph of 6, contact time of 60 minutes, the ambient temperature of 25°c, and adsorption dose of 0.2 g. in the case of adsorption kinetics, the pseudosecond order model and intraparticle diffusion had more fitness with the experimental data indicating a chemical equilibrium between the adsorbate and the absorbent. thermodynamic studies demonstrated that the process (negative δg) is spontaneous (negative δg), endothermic (negative δh), and nonrandom (positive δs). thus, lcnf can be used as an effective adsorbent in the removal of metals by having an extremely high surface area.