Elsevier

Ecological Engineering

Volume 82, September 2015, Pages 258-266
Ecological Engineering

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

https://doi.org/10.1016/j.ecoleng.2015.04.041Get rights and content

Highlights

  • 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.

Abstract

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 8.74 mg/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.

Introduction

One important and abundant fission radionuclide applied in nuclear power production is 137Cs (Lan et al., 2014). The use of 137Cs radionuclide for power production has been shown to have huge environmental effects on the ecosystem due to the formation of large amounts of γ radiations, the long half-life of 137Cs (30 years) and its high water solubility and labialization (Mashkani and Ghazvini, 2009). Various studies have shown that water and soils close to nuclear plants have been contaminated by radionuclides, which affects both plant and animal life (Nakano and Yong, 2013, Yang et al., 2014). To successfully manage such nuclear facilities, there is a need to effectively control the levels of radionuclides in the effluent water from these facilities. Therefore adsorbents that can selectively and efficiently remove these radionuclides from process and effluent waters in nuclear plants before they are discarded into water bodies needs to be developed (Takei et al., 2014).

Several adsorbent types based on the immobilization of nickel-hexacyanoferrate onto mineral surfaces have been produced (Loos-Neskovic et al., 1984, Rajec et al., 2000). These adsorbents have been shown to be effective and highly selective due to the affinity of hexacyanoferrate complex for Cs+ in solution. Recently, materials of biological origin such as Coir pith (Parab and Sudersanan, 2010), Agaricus bisporus mushroom (Vrtoch et al., 2011) and walnut shell (Ding et al., 2013) have been applied as support for hexacyanoferrate complex for Cs+ adsorption from solution. These lignocellulosic materials have the advantage of being naturally abundant in nature, low-cost and consisting of functional groups to which ligands can be attached by specific chemical reactions. In this study, a biosorbent based on the immobilization of hexacyanoferrate complex via interaction with iron(III) onto pine cone biomass surface was produced and tested for its ability to remove Cs+ from aqueous solution. The pine cone used was initially treated with toluene–ethanol mixture to remove plant extracts and to improve surface properties of the raw pine. Some surface characterization such as bulk density, pHPZC, and FTIR were performed on the adsorbent composite material. Kinetic and equilibrium data were analyzed using nonlinear regression program of the KyPlot 2.0 software which uses Quasi-Newton algorithm for finding the parameter values which minimize the sum of the squares of the errors (ERRSQ). The correlation coefficient and chi-square error methods were applied in determination of best fit. Desorption studies was also performed to examine the mechanism of uptake of the biosorbent produced.

This work is therefore aims at the incorporation of hexacyanoferrate complex onto pine cone and the effect of the added complex on its ability to remove Cs+ from aqueous solution. The uptake of Cs+ onto RPC, TPC and HPC was studied by various kinetic and equilibrium models.

Section snippets

Materials

Raw pine cone (RPC) was collected from a plantation in Sasolburg, Free State, South Africa. The cones were washed to remove impurities such as sand and leaf. The washed cones were then dried at 90 °C for 48 h in an oven. The scales on the cones were removed and crushed using a pulveriser. The pine cone powder was then sieved and particles between 90 and 45 μm were collected and used for the study.

Preparation of pine cone

Raw pine cone (RPC) powder (50 g) was extracted with 250 cm3 mixture of toluene:ethanol ratio of 2:1

Properties of pine cone and TPC pine cone

A comparison of properties such as bulk density, point zero charge (pHPZC) and iodine capacity of RPC, TPC and HPC are shown in Table 1. The results revealed that the bulk density of the TPC was lower than that of RPC. This implies that plant organic components were leached out of the pine cone matrix leading to a reduction in bulk density, since it is known that bulk density of a powdered sample reduces with increasing amount of void spaces present in the powder (Wartelle and Marshall, 2000).

Conclusion

A two-step synthesis of an ion-exchange resin produced by immobilizing hexacyanoferrate complex onto pine cone loaded with iron(III). The results from FTIR analysis and thermal analysis indicates that the iron(III) incorporation occurred while the sharp FTIR peak at 2045 cm−1 confirmed incorporation of hexacyanoferrate complex on the pine cone. The two stage decomposition seen in the derivative weight loss plot also confirmed the incorporation. Cs+ ions removal capacity was in the order of RPC < 

References (27)

  • L.H. Wartelle et al.

    Citric acid modified agricultural by-products as copper ion adsorbents

    Adv. Environ. Res.

    (2000)
  • H. Yang et al.

    Magnetic Prussian blue/graphene oxide nanocomposites caged in calcium alginate microbeads for elimination of cesium ions from water and soil

    Chem. Eng. J.

    (2014)
  • A. Bismarck et al.

    Surface characterization of natural fibers; surface properties and water up-take behavior of modified sisal and coir fibers

    Green Chem.

    (2001)
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