Abstract The magnetic nanoparticles prepared through the co-precipitation method were surface modified using Spirulina platensis. The mesoporous and superparamagnetic nature of the adsorbent was confirmed by Brunauer-Emmett-Teller (BET) and vibrating sample magnetometer (VSM) analyses, respectively. Further, an increased specific surface area of 75.3 m2/g was reported in the BET studies. Parameters such as pH, contact time, concentration, and temperature were studied to optimize the operating conditions influencing adsorption. Thermodynamic studies justified the spontaneity and endothermic nature of adsorption. The adsorbent exhibited a better performance at 1.5 pH and 120 minutes of contact time. The monolayer adsorption capacity of the material was found to be 29.23 mg/g from the evaluation of Langmuir adsorption isotherm. The second- order kinetic studies suggest the predominance of chemisorption. Further, the X-ray photoelectron spectroscopy (XPS) studies confirmed that the adsorption mechanism is electrostatic attraction accompanied by reduction. Notably, a regeneration efficiency of 75.26% was achieved with NaOH as the desorbing agent.
S. Mohan, Govindankutty, G., Dr. Asha Sathish, and Nithya K., “Spirulina platensis-capped mesoporous magnetic nanoparticles for the adsorptive removal of chromium”, The Canadian Journal of Chemical Engineering, 2020.