A Comparison Study of Mechanism: Cu2+Adsorption on Different Adsorbents and Their Surface-Modified Adsorbents

Yaqin Yu,Xinrui Li,Jiemin Cheng

doi:10.1155/2016/7936258

Abstract

The isothermal adsorption kinetics of Cu2+onto Carbon Black (CB) and Oxidized Carbon Black (OCB) were studied under different solution conditions and compared with bentonite and organic bentonite with the hexadecyltrimethylammonium bromide (HDTMA). The adsorption capacities followed the order of OCB > CB > organic bentonite > bentonite, which was consistent with the orders of their surface roughness and specific surface area. The Fourier transmission infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM) were used to explore the adsorption mechanism at molecular level. The adsorption process onto CB was physical adsorption. However, with the increase of oxygen-containing functional groups (C=O, C-O, and CNO), the chelation adsorption onto OCB became gradually dominant except physical adsorption. The ion exchange adsorption was the major adsorption mechanism of bentonite. The compounds were introduced into clay interlayer by complexing reaction with Cu2+, which improved the adsorption capacity of organic bentonite. The results present a significant implication for the environmental fate assessment of heavy metal pollution.

Highlights

In recent decades, increased copper (Cu) contamination in soil has created a global concern [1]
Compared with Carbon Black (CB), the Oxidized Carbon Black (OCB) shows a lot of pores, which further suggests that the surface area increases
We discover that the adsorption mechanisms of Cu2+ on CB, bentonite, and their surface-modified materials are different

Summary

Introduction

In recent decades, increased copper (Cu) contamination in soil has created a global concern [1]. The most important criterion for adsorption technique is the selectivity of efficient adsorbents with high adsorption capacity and cost efficiency. The common adsorbents, such as activated carbon [7], dolomite [8], chitosan [9], and pomegranate peel [10], have been developed and expressed high-effective adsorption of heavy metal. Surface-modified CB has high adsorption capacity of heavy metals [17, 18]. The modified bentonite has high adsorption capacities of organics (including propylmercaptan, aroma compounds, and dye) [20, 21], it is less efficient for heavy metals. The results present an innovative material for developing remedy technology of heavy metal pollution

Materials and Methods

Results and Discussion

Conclusions