Heavy metal adsorption by ion exchange resin made from bamboo powder and surface modification with manganese oxide

Abstract

The objective of this work was to study the adsorption efficiency of bamboo and its surface modified with manganese oxide for removal of Pb(II) ion. The adsorption of Pb(II) from aqueous solution onto bamboo (BB) and manganese oxide-modified bamboo powder (MnO-BB) was evaluated based on batch experiment. The adsorption efficiency of MnO-BB onto Pb(II) was investigated as a function of the initial pH of 6, equilibrium time of 30 min, adsorbent concentration of 5 g/L and initial concentration of Pb(II) solution in the range of 50-500 mg/L. The adsorption isotherms of Langmuir, Freundlich and Dubinin-Radushkevich were used to describe the equilibrium isotherm. It is observed that the data from MnO-BB adsorbents fitted well to the Langmuir isotherm. The maximum monolayer adsorption capacities of MnO-NC were estimated as 38.76 mg/g. By comparing with BB, the amount of Pb(II) adsorbed onto MnO-BB was more than BB by about 40 times under the optimized adsorption condition. According to Dubinin-Radushkevich isotherm, the adsorptive mechanism of Pb(II) onto MnO-BB was chemisorption. The kinetic studies of Pb(II) demonstrated that the adsorption of Pb(II) onto MnO-BB adsorbent followed a pseudo second-order model with a good correlation. The adsorption mechanism was processed via chemical ion exchange between H+ and bonded MnO groups and Pb(II) ions in solution