Adsorption of Pb(II) on activated carbon prepared from Polygonum orientale Linn.: Kinetics, isotherms, pH, and ionic strength studies

doi:10.1016/j.biortech.2010.02.099

Bioresource Technology

Volume 101, Issue 15, August 2010, Pages 5808-5814

https://doi.org/10.1016/j.biortech.2010.02.099 Get rights and content

Abstract

Low-cost activated carbon was prepared from Polygonum orientale Linn. (PL) by phosphoric acid activation. Its ability to adsorb Pb(II) ions from aqueous solutions was examined. Through SEM, XRD, BET, and FTIR analyses, the PL-activated carbon (PLAC) was found to have a porous structure with a surface area of about 1400 m²/g. Carboxyl groups played an important role in the adsorption of Pb(II) through blocking studies. The sorption system followed a pseudo second-order kinetic model, and the equilibrium time was obtained after 30 min. The adsorption isotherms were simulated well by the Langmuir model. The adsorption of Pb(II) on PLAC was strongly dependent on pH and ionic strength, indicating an ion-exchange mechanism. Regeneration studies showed that PLAC could be used several times by desorption with an HCl reagent.

Introduction

Heavy metals are known to be harmful to humans. They are important contaminants in the liquid wastes of a number of industries such as plating, paint and dyes, glass operations, lead batteries, electroplating, mining, and smelters (Aroua et al., 2008). Among the heavy metals, lead is one of the most toxic elements, even at low concentrations. It affects the central nervous system, kidneys, liver, and gastrointestinal system, and it may directly or indirectly cause diseases such as anemia, encephalopathy, hepatitis, and the nephritic syndrome (Martins et al., 2006). There are various techniques for reducing the toxicity of heavy metals, including chemical precipitation, adsorption, electrolysis, ion exchange, and membrane separation. Among the aforementioned methods, adsorption has been proven to be one of the simplest and most effective techniques (Mckay et al., 1999). Currently, activated carbon is widely used as an adsorbent in wastewater treatments. It has highly developed porosity, a large internal surface area, and relatively high mechanical strength. Despite its widespread use in industries, activated carbon remains an expensive material. Therefore, it is necessary to investigate and develop low-cost effective carbons that can be applied to water pollution control. A wide variety of low-cost materials have been exploited to remove contaminants from aqueous solutions, including hazelnut husks (Imamoglu and Tekir, 2008), coconut shells (Kikuchi et al., 2006), peanut hulls (Brown et al., 2000), palm shells (Issabayeva et al., 2006), pecan shells (Bansode et al., 2003), and algal wastes (Vilar et al., 2005).

Polygonum orientale Linn. (PL) is a fast-growing robust annual herbage (Polygonum genus, Polygonaceae family) that is widely distributed in China (Ferrero et al., 1998). It can be reproduced from rhizomes even in small fragments; thus, it can easily be transferred to new sites, particularly in riparian areas. Due to its strong adaptability and productive character, PL has been widely used in constructed wetlands for wastewater treatment, with above-ground standing crops averaging from 1400 to 6500 kg/ha (Haukos and Smith, 1993). Dead PL is often abandoned or burned as firewood. However, it has a porous caudex system, and it can produce large quantities of biomass (Ferrero et al., 1998), which may offer a good basis for the production of an effective activated carbon. No investigations, however, have been carried out to adsorb heavy-metal ions by using Polygonum-orientale-Linn.-activated carbon (PLAC).

Consequently, this paper aims to evaluate the application potential of developing an effective low-cost adsorbent from PL by H₃PO₄ activation and to investigate its ability to treat wastewater that contains toxic lead. The properties of PLAC are investigated through SEM, XRD, BET, and FTIR analyses. The adsorption performances (i.e., contact time, shaking rate, temperature, pH, and ionic strength) of PLAC are systematically studied at various scenarios.

Section snippets

Preparation of PLAC

The PL in this paper was obtained from Nansi Hu, Shandong, China. It was cut into small pieces of 2–3 cm and was sun dried for 8 h until all the moisture evaporated. The sample was then ground to a fine powder using a steel blender and was oven dried at 110 °C for 2 h. The dried mass was afterward soaked in H₃PO₄ (45 wt.%) at a ratio of 2.4:1 (g H₃PO₄/g PL) and was allowed to carbonize at 450 °C in a tube furnace (SRJK-2-13, Beijing, China) for 1 h. After cooling and under an ambient temperature, the

Properties of PLAC

The morphological features and surface characteristics of adsorbent materials are widely studied by using SEM and XRD methods. The SEM image of PLAC is shown in Fig. 1. The adsorbent appeared to have a coarse porous surface with irregular pores. The XRD indicated an amorphous structure of PLAC because no apparent diffraction peaks were obtained over the whole ranges. This result was probably due to the internal etching during H₃PO₄ activation. The acid first produces a hydrolysis of the

Conclusions

The H₃PO₄-activated PL acts as a good adsorbent to adsorb Pb(II) from aqueous solutions. The adsorption follows pseudo second-order kinetics, and the equilibrium data can be well fitted with the Langmuir isotherms. The adsorption of Pb(II) on PLAC increases with the increase in pH, and it significantly decreases with the increase in ionic strength, which indicates an ion-exchange mechanism. Furthermore, PLAC has a strong ability for regeneration. Therefore, PLAC has a great potential to be used

Acknowledgements

The work was supported by the National Key Technology R&D Program for the 11th Five-year Plan (No. 2006BAC10B03), Major National Science and Technology Project (No. 2009ZX07210-009) and Special Science Innovation Foundation of Shandong University (2009JQ009).

References (34)

C. Aguilar et al.
Catalyticwet air oxidation of aqueous ammonia with activated carbon
Appl. Catal. B–Environ.
(2003)
M.K. Aroua et al.
Real-time determination of kinetics of adsorption of lead(II) onto palm shell-based activated carbon using ion selective electrode
Bioresour. Technol.
(2008)
R.R. Bansode et al.
Adsorption of metal ions by pecan shell-based granular activated carbons
Bioresour. Technol.
(2003)
P. Brown et al.
Evaluation of the adsorptive capacity of peanut hull pellets for heavy metals in solution
Adv. Environ. Res.
(2000)
C.L. Chen et al.
Influence of pH, soil humic/fulvic acid, ionic strength and foreign ions on sorption of thorium(IV) onto (–Al₂O₃
Appl. Geochem.
(2007)
W.H. Cheung et al.
Intraparticle diffusion processes during acid dye adsorption onto chitosan
Bioresour. Technol.
(2007)
M.A. Díaz-Díez et al.
Porous texture of activated carbons prepared by phosphoric acid activation of woods
Appl. Surf. Sci.
(2004)
P.E. Fanning et al.
Drifts study of the formation of surface groups on carbon by oxidation
Carbon
(1993)
M. Imamoglu et al.
Removal of copper (II) and lead (II) ions from aqueous solutions by adsorption on activated carbon from a new precursor hazelnut husks
Desalination
(2008)
G. Issabayeva et al.
Removal of lead from aqueous solutions on palm shell activated carbon
Bioresour. Technol.
(2006)

M.H. Kalavathy et al.

Kinetic and isotherm studies of Cu(II) adsorption onto H₃PO₄-activated rubber wood sawdust

J. Colloid Interf. Sci.

(2005)

Y. Kikuchi et al.

Effect of ZnO loading to activated carbon on Pb(II) adsorption from aqueous solution

Carbon

(2006)

Y.H. Li et al.

Adsorption thermodynamic, kinetic and desorption studies of Pb²⁺ on carbon nanotubes

Water Res.

(2005)

J. Lützenkirchen

Ionic strength effects on cation sorption to oxides: macroscopic observations and their significance in microscopic interpretation

J. Colloid Interf. Sci.

(1997)

B.L. Martins et al.

Sorption and desorption of Pb²⁺ ions by dead Sargassum sp

Biomass. Biochem. Eng. J.

(2006)

C. Moreno-Castilla et al.

Changes in surface chemistry of activated carbons by wet oxidation

Carbon

(2000)

S. Rengaraj et al.

Kinetics of removal of chromium from water and electronic process wastewater by ion exchange resins 1200H, 1500H and IRN97H

J. Hazard. Mater.

(2003)

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Adsorption of Pb(II) on activated carbon prepared from Polygonum orientale Linn.: Kinetics, isotherms, pH, and ionic strength studies

Abstract

Introduction

Section snippets

Preparation of PLAC

Properties of PLAC

Conclusions

Acknowledgements

Appl. Catal. B–Environ.

Bioresour. Technol.

Bioresour. Technol.

Adv. Environ. Res.

Appl. Geochem.

Bioresour. Technol.

Appl. Surf. Sci.

Carbon

Desalination

Bioresour. Technol.

J. Colloid Interf. Sci.

Carbon

Water Res.

J. Colloid Interf. Sci.

Biomass. Biochem. Eng. J.

Carbon

J. Hazard. Mater.