Adsorption of cadmium from aqueous solutions by novel FeO- newly isolated Actinomucor sp. bio-nanoadsorbent: functional group study.

A novel bio-nanocomposite was prepared by the combination of fungal biomass and FeO magnetic nanoparticles. The result of XRD and EDAX analysis indicated that FeO Actinomucor sp. bio-nanoadsorbent was prepared. Our experiments showed that the adsorption kinetics and isotherm of this material comply with the pseudo-second-order and the Langmuir models, respectively. The maximum adsorption capacity (q) of this novel bio-nanoadsorbent was obtained as 29.49 mg/g. The thermodynamic analysis revealed that the adsorption of Cd is spontaneous and exothermic. The optimum temperature, initial concentration, contact time and pH for adsorption system of cadmium were about 45 °C, 400 mg/L, 120 min and 7, respectively. Pretreatment of adsorbent by NaOH and SDS significantly increased cadmium adsorption capacity. SEM images showed that FeO nanoparticles were immobilized successfully on the fungus cell surface. Contribution of the carboxyl, hydroxyl, amine and Fe-O functional groups of the bio-nanoadsorbent in the binding to cadmium ions was revealed by FTIR analysis. Results from regeneration studies indicated reusability of the adsorbent up to 91%. According to experimental results, it could be claimed that bio-nanocomposite of FeO-Actinomucor sp. is a novel efficient adsorbent for removal of metal ions from aqueous solutions, and hence it has potential to be used in the environmental pollution cleanup programs.