Application of raw and modified pine biomass material for cesium removal from aqueous solution

• Published in: Ecological engineering 2015-09, Vol.82, p.258-266
• Main Authors: Ofomaja, A.E., Pholosi, A., Naidoo, E.B.
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Biomass; Cesium; Hexacyanoferrate; Ion exchangers; Ion-exchange mechanism; Isotherm model; Isotherms; Kinetic model; Pine; Pine cone; Raw; Surface chemistry
• ISSN: 0925-8574; 1872-6992
• DOI: 10.1016/j.ecoleng.2015.04.041

[Display omitted] •Preparation of toluene–ethanol treated pine cone.•Immobilization of hexacyanoferrate ligand on treated pine cone.•Characterisation of raw, treated and modified pine cone.•Comparison of cesium uptake kinetics onto raw, treated and modified pine cone.•Comparison of equilibrium adsorption and desorption of cesium onto raw, treated and modified pine cone. The growing investment in nuclear power has led to increasing concentrations of radionuclides in the ecosystem near nuclear facilities, therefore cheap and efficient filter materials for removal of these radionuclides needs to be designed to handle effluent waters from these facilities. The study investigates the use of hexacyanoferrate complex immobilized on chemically treated pine cone (TPC) biomass as an effective adsorbent. Raw pine cone (RPC) was treated with toluene–ethanol mixture to extract plant components and modified with hexacyanoferrate complex (HPC). Properties of RPC, TPC and HPC such as pHPZC, bulk density and surface area, and types of functional groups on the sorbent surface were determined. The batch kinetic uptake of cesium ions onto RPC, TPC and HPC were modelled using the Elovich and pseudo-nth order model kinetic models. Equilibrium modelling was also performed using the Langmuir, Freundlich and Sips isotherm. The results revealed that the adsorption is monolayer for all biosorbents with the modified adsorbent having the highest capacity of 8.74mg/g which was also confined by the Sips isotherm. The Cs+ adsorption data for TPC and HPC were better fitted to the pseud-nth order model suggesting ion exchange mechanism while the RPC was better fitted to the Elovich model. Desorption analysis was also used to confirm ion-exchange mechanism.