Effective Remediation of Lead Ions from Aqueous Solution by Chemically Carbonized Rubber Wood Sawdust: Equilibrium, Kinetics, and Thermodynamic Study

Swarup Biswas,Umesh Mishra

doi:10.1155/2015/842707

Abstract

Rubber wood sawdust was carbonized into charcoal by chemical treatment which was used for removal of lead ion from aqueous solution. The work involves batch experiments to investigate the pH effect, initial concentration of adsorbate, contact time, and adsorbent dose. Experimental data confirmed that the adsorption capacities increased with increasing inlet concentration and bed height and decreased with increasing flow rate. Adsorption results showed a maximum adsorption capacity of 37 mg/g at 308 K. Langmuir, Freundlich, and Temkin model adsorption isotherm models were applied to analyze the process where Temkin was found as a best fitted model for present study. Simultaneously kinetics of adsorption like pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were investigated. Thermodynamic parameters were used to analyze the adsorption experiment. Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy confirmed the batch adsorption of lead ion onto chemically carbonized rubber wood sawdust.

Highlights

Water pollution due to contamination of toxic lead ions is a serious problem for human health and environment
Before and after adsorption functional groups were identified by using Fourier transform infrared spectroscopy (FTIR) in the range of 400–4000 cm−1 as shown in Figures 1 and 2
In chemically carbonized rubber wood sawdust (CCRWSD) the peak at 1708.58 cm−1 and 1612.56 cm−1 shows the presence of C=O group and –COO− group

Summary

Introduction

Water pollution due to contamination of toxic lead ions is a serious problem for human health and environment. According to the US Environmental Protection Agency (EPA), World Health Organization (WHO), and Indian Standard (IS), permissible limit of lead ion in drinking water is 0.015 mg/L, 0.01 mg/L, and 0.05 mg/L, respectively. Commercial methods such as filtration, chemical oxidation/reduction, electrochemical treatment, chemical precipitation, membrane separation, and ionexchange methods have been utilized for the remediation of heavy metal contamination. In this study we adopted adsorption process for removal of lead ion. In this study chemically carbonized rubber wood sawdust (CCRWSD) was utilized for removal of lead ions from synthetic wastewater. Kinetic, and thermodynamic study were carried out to compare the experimental data and to understand the adsorption behavior of lead ion onto CCRWSD

Materials and Methods

Results and Discussion

Conclusions