Removal of Cd²⁺ by N-CNS/ZnO nanocomposite from wastewater and reuse of Cd²⁺-N-CNS/ZnO in blood fingerprint detection

In this study, an N-CNS/ZnO nanocomposite was used to adsorb the Cd²⁺ ion from an aqueous solution, and the spent Cd-loaded absorbent was reused in blood fingerprint detection. N-carbon nanosheets (N-CNS) were produced from potato peels and then coated with ZnO nanoparticles. XRD, TEM, SEM, and FTIR were used to examine the sample functionality and Surface morphology. The effect of pH, adsorbent dosage, temperature, and time was examined using ICP-OES. Removal efficiencies optimum conditions for the Cd²⁺ were pH 8 with 99.05 %, adsorbent dosage of 100 mg with 99,97 %, temperature (55) with 93,34 % and time (3 h) with 91,24 %. Additionally, the adsorption pseudo-second-order and Langmuir isotherm models were best fitted for Cd²⁺ ion removal. The maximum adsorption capacity of Cd²⁺ ions was 8.762 mg/g. Therefore, N-CNS/ZnO nanocomposite can remove Cd²⁺ ions in wastewater, and its potential for re-use in blood fingerprint detection helps eliminate secondary environmental pollution.