Development of Absorbent Using Amylose-Graphite Composite Electrode for Removal of Heavy Metals.

Shuang Li,Guizani Mokhtar,Ryusei Ito,Toshikazu Kawaguchi

doi:10.3390/membranes11120930

Abstract

Amylose of Phragmites Australis captures heavy metals in a box consisting of sugar chains. However, its absorption rate is low in the period of the month scale. Therefore, the electrochemical driving force was used to promote the absorption rate in this research. Amylose was doped with TiO2 porous graphite electrode. The composted absorbent was characterized using XRD(X-ray diffraction), SEM (Scanning Electrode Microscopy), Raman spectroscopy, and electrochemical methods. The affinity and maximum absorption amount were calculated using the isotherm method. In this study, Pb2+, Cu2+, Cd2+, and Cr6+ were chosen to demonstrate because these heavy metals are significant pollutants in Japan’s surface water. It was found that the maximum absorption was Cu2+ (56.82-mg/L) > Pb2+ (55.89-mg/L) > Cr6+ (53.97-mg/L) > Cd2+ (52.83.68-mg/L) at −0.5 V vs. Ag/AgCl. This is approximately the same order as the hydration radius of heavy metals. In other words, the absorption amounts were determined by the size of heavy metal ions. Subsequently, the mixed heavy metal standard solution was tested; the maximum absorption amount was 21.46 ± 10.03 mg/L. It was inferred that the electrochemical driving force could be shown as the ion size effect in the mixed solution. Despite there being no support for this hypothesis at this time, this study succeeded in showing that the electrochemical driving force can improve the ability of the absorbent.

Highlights

Rising population, factory expansion, urbanization, agricultural activities, and various chemicals usage have led to serious environmental issues [1,2]
Regarding these illnesses, WHO stipulates the standard for different types of heavy metals in water bodies: the copper concentration should be less than 2 mg/L, chromium is set at 0.05 mg/L, cadmium must be less than 0.003 mg/L, and lead must be maintained below
The performance of amylose-doped TiO2-doped graphite porous carbon absorption depended on the initial concentration of heavy metals, and the absorption equilibrium concentration was 100 mg/L

Summary

Introduction

Factory expansion, urbanization, agricultural activities, and various chemicals usage have led to serious environmental issues [1,2]. Water contamination is the most important of these environmental issues to examine, as water quality has a direct link to human health, as hazardous substances are absorbed in bodily organisms through the food chain and drinking water [1]. Chromium, cadmium, and lead are the most common heavy metal contaminants in Japan. Heavy metal contamination in water bodies has resulted in numerous illnesses, such as ITAI-ITAI disease, lead poisoning, and skin fester [9]. Regarding these illnesses, WHO stipulates the standard for different types of heavy metals in water bodies: the copper concentration should be less than 2 mg/L, chromium is set at 0.05 mg/L, cadmium must be less than 0.003 mg/L, and lead must be maintained below

Methods

Results

Conclusion