Eco-Friendly Reduced Graphene Oxide Nanofilter Preparation and Application for Iron Removal

Pankaj Kumar Jha,Chamorn Chawenjkigwanich,Md Shahariar Chowdhury,Kuaanan Techato,Watsa Khongnakorn

doi:10.3390/separations8050068

Abstract

In this paper, the green synthesis of reduced graphene oxide (r-GO) nanomaterials using Callistemon viminalis leaf extract as a reducing and stabilizing agent is reported for the first time. The synthesized r-GO nanomaterials were characterized using UV–Vis, XRD, FE-SEM, TEM, and energy dispersive X-ray (EDX) analyses. The nanofilter membrane was prepared by varying the amounts of r-GO nanomaterials in a Polysulfone-N,N-dimethyl formamide (DMF) solution. The nanofilter membrane was characterized by the contact angle, atomic force microscopy (AFM), UV–Vis, and FTIR. The results confirm the formation of r-GO nanomaterials. Higher amounts of r-GO nanomaterials in the membrane show a lower contact angle, thus confirming their hydrophilic nature. Iron water filtration was performed with different amounts of r-GO nanomaterials in the membrane filter, and the water flux was smooth over an increased time period. Inductively Coupled Plasma (ICP) analysis showed a higher percentage of iron rejection (95.77%) when higher amounts (0.10 g) of r-GO nanomaterials were used in a mixed membrane (i.e., sample C). In conclusion, the findings illustrate that Callistemon viminalis mediates the synthesis of r-GO nanomaterials, which is useful in water filtration, and can be incorporated into membrane filters, since it removes iron.

Highlights

Pure drinking water is essential for human health
Nowadays, reduced graphene oxide nanomaterials are of interest to researchers in water filtration applications due to their nanosized pores; a cost-effective and eco-friendly synthesis method is still required
Our findings show that mass production of reduced graphene oxide nanomaterials could be possible in the near future for eco-friendly heavy metals removal from drinking water at a low cost, thereby overcoming the challenges posed by physical and chemical methods in mass production for reduced graphene oxide nanomaterials

Summary

Introduction

Pure drinking water is essential for human health. Health can be negatively affected by the contaminants present in drinking water [1]. Heavy metals have a higher density than water, and various heavy metals that are present in the earth’s crust mix with water and affect human health after consumption. Toxic heavy metals’ effects on genetic materials alter normal body metabolism [2]. Heavy metals, such as chromium, lead, manganese, mercury, zinc, cadmium, and iron, have more toxic effects on human health [3]. The standard filtration method of ionic removal of toxic heavy metal from is inefficient [5], but small pore sizes in membrane filtration were shown to be effective in water filtration [6]

Results

Discussion

Conclusion