High-Performance Capacitive Deionization Disinfection of Water with Graphene Oxide-graft-Quaternized Chitosan Nanohybrid Electrode Coating

Abstract

Water disinfection materials should ideally be broad-spectrum-active, nonleachable, and noncontaminating to the liquid needing sterilization. Herein, we demonstrate a high-performance capacitive deionization disinfection (CDID) electrode made by coating an activated carbon (AC) electrode with cationic nanohybrids of graphene oxide-graft-quaternized chitosan (GO-QC). Our GO-QC/AC CDID electrode can achieve at least 99.9999% killing (i.e., 6 log reduction) of Escherichia coli in water flowing continuously through the CDID cell. Without the GO-QC coating, the AC electrode alone cannot kill the bacteria and adsorbs a much smaller fraction (<82.8 ± 1.8%) of E. coli from the same biocontaminated water. Our CDID process consists of alternating cycles of water disinfection followed by electrode regeneration, each a few minutes duration, so that this water disinfection process can be continuous and it only needs a small electrode voltage (2 V). With a typical brackish water biocontamination (with 10(4) CFU mL(-1) bacteria), the GO-QC/AC electrodes can kill 99.99% of the E. coli in water for 5 h. The disinfecting GO-QC is securely attached on the AC electrode surface, so that it is noncontaminating to water, unlike many other chemicals used today. The GO-QC nanohybrids have excellent intrinsic antimicrobial properties in suspension form. Further, the GO component contributes toward the needed surface conductivity of the CDID electrode. This CDID process offers an economical method toward ultrafast, contaminant-free, and continuous killing of bacteria in biocontaminated water. The proposed strategy introduces a green in situ disinfectant approach for water purification.

Identification of Two Depolymerases From Phage IME205 and Their Antivirulent Functions on K47 Capsule of Klebsiella pneumoniae

“…The hemolytic effect of depolymerases to erythrocytes was performed using previously described methods with minor modifications (Wang et al, 2015). The separated erythrocytes were washed and diluted to a concentration of 5% (v/v) with PBS.…”

Graphene-based nanomaterials in biosystems

“…Srikanth et al [201] fabricated Ag/Ag2O core/shell and Ag/Ag2O decorated multi-layered graphene (MLG) nanostructures with excellent adsorption capabilities to remove As(III) from water, as well as high antimicrobial ability against E. coli and S. aureus. Wang et al [202] reported an activated carbon (AC) electrode coated with graphene oxide-graft-quaternized chitosan (GO-QC) through capacitive deionization disinfection (CDID). It was found that GO-QC/AC CDID electrode could kill at least 99.9999% of E. coli and be easily regenerated in continuous water through the CDID cell, but showed no observable contamination to the water.…”

Pebax®1657/Graphene oxide composite membranes for improved water vapor separation

“…Graphene oxide is attractive as nano filler because of its high aspect ratio and its ease of functionalization with the hydrophilic polymers. GO nanosheets can be easily dispersed in water due to the presence of hydroxyl, carbonyl, epoxy, and carboxylic groups [12][13][14][15]. The high aspect ratio increases the path length molecules have to travel due to an increase in tortuosity.…”