Adsorption Characteristics of Multi-Metal Ions by Red Mud, Zeolite, Limestone, and Oyster Shell

Abstract

In this study, the performances of various adsorbents—red mud, zeolite, limestone, and oyster shell—were investigated for the adsorption of multi-metal ions (Cr3+, Ni2+, Cu2+, Zn2+, As3+, Cd2+, and Pb2+) from aqueous solutions. The result of scanning electron microscopy analyses indicated that the some metal ions were adsorbed onto the surface of the media. Moreover, Fourier transform infrared spectroscopy analysis showed that the Si(Al)-O bond (red mud and zeolite) and C-O bond (limestone and oyster shell) might be involved in heavy metal adsorption. The changes in the pH of the aqueous solutions upon applying adsorbents were investigated and the adsorption kinetics of the metal ions on different adsorbents were simulated by pseudo-first-order and pseudo-second-order models. The sorption process was relatively fast and equilibrium was reached after about 60 min of contact (except for As3+). From the maximum capacity of the adsorption kinetic model, the removal of Pb2+ and Cu2+ were higher than for the other metal ions. Meanwhile, the reaction rate constants (k1,2) indicated the slowest sorption in As3+. The adsorption mechanisms of heavy metal ions were not only surface adsorption and ion exchange, but also surface precipitation. Based on the metal ions’ adsorption efficiencies, red mud was found to be the most efficient of all the tested adsorbents. In addition, impurities in seawater did not lead to a significant decrease in the adsorption performance. It is concluded that red mud is a more economic high-performance alternative than the other tested adsorption materials for applying a removal of multi-metal in seawater.

Kinetic study on removal of heavy metal ions from aqueous solution by using soil

“…In addition, the band at 990-1050 cm −1 , present in the virgin soil sample, can be assigned to the stretching vibrations of Si(Al)-O. This band is sensitive to the content of structural Si and Al (Shin et al 2014). The analysis has proved that the Si(Al)-O bond is involved in heavy metal adsorption.…”

“…On the other hand, the elemental compositions of soil were determined by randomly selecting areas on the solid surfaces and analyzing by EDX. SEM-EDX system was employed to quantify and map elemental spatial distributions on the surfaces of soil (Shin et al 2014).…”

A Mineral By-Product from Gasification of Poultry Feathers for Removing Cd from Highly Contaminated Synthetic Wastewater

“…The effects on Cd sorption of five operational conditions were studied: wastewater pH, adsorbent dosage, contact time, metal concentration and wastewater salinity. The experimental conditions for Cd adsorption were adapted from suitable references [31][32][33][34][35]. The setup for Cd sorption with the ranges of the operational conditions is presented in Figure 2.…”

Adsorption characteristics of As(III) and Cr(VI) from aqueous solution by Sediment Amendment Composite

“…따라서 현재 많은 연구자들에 의해 새로운 반 응성 피복소재 개발이 이루어지고 있는 가운데 국내에서도 다양한 소재를 이용해 반응성 피복소재로의 가능성을 제시 하고 있다. 그 중 대표적인 재료로는 굴 패각 (Hsu, 2009;Shin et al, 2014), 적니 (Bertocchi et al, 2006;Shin et al, 2014), 제올라이트 (Kocaoba et al, 2007;Shin et al, 2014), 순환골재 (Ok et al, 2007;Shin and Kim, 2015), 제강슬래 그 (Shin and Kim, 2014), 벤토나이트 (Kozar et al, 1992;Shin and Kim, 2014) (Hyun et al, 2007;Ryu et al, 2011 Fig. 1(a) (Shin and Kim, 2013 McKay, 1999a, 1999b).…”

“…Fig. 1(b) (Hsu, 2009;Shin et al, 2014), 순환 골재 (Ok et al, 2007;Shin and Kim, 2015) 및 제강슬래그 (Shin and Kim, 2014) (Clayden et al, 1991;Ortego and Barroeta, 1991). 마지막으로 538 cm -1 (Yang et al, 2014).…”