Removal of graphene oxide nanomaterials from aqueous media via coagulation: Effects of water chemistry and natural organic matter. (February 2017)

• Record Type: Journal Article
• Authors: Duan, Lin; Hao, Rongjie; Xu, Zhu; He, Xizhen; Adeleye, Adeyemi S.; Li, Yao
• Is Part Of: Chemosphere. Volume 168(2017)
• Page Start: 1051
• Page End: 1057
• Publication Date: 2017-02
• Subjects: Graphene oxide -- Alum -- Coagulation -- Removal efficiency; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.10.104
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: With the increasing use of graphene oxide (GO) nanomaterials, its possible environmental release and human effects have received much attention. As GO may enter drinking or wastewater treatment systems like other carbonaceous nanomaterials, and have potential impact on human and/or environmental health, its removal efficiency during water treatment is important and requires investigation. In this study, the removal efficiency of GO during water treatment procedure via coagulation was evaluated, and the effects of solution chemistry and natural organic matter on the coagulation-based removal of GO nanomaterials were investigated. The results indicate that the removal efficiency of GO with alum coagulation can reach 80% with 20 mg/L alum dosage at neutral pH, and will not change significantly with higher concentration of alum. The coagulation mechanism and efficiency were strongly affected by the Al species in aqueous phase, which are controlled by pH. Co-existing cations (e.g. Na) may have minimal effect on GO removal efficiency, and the presence of humic acid (HA) suppresses coagulation remarkably at alum concentrations below 40 mg/L. The results from this study provide critical information for predicting the removal efficiency of GO nanomaterials during alum coagulation phase of water treatment procedure. Graphical abstract: Highlights: GO surface charges greatly affect the coagulation of GO. The removal efficiency of GO with alum coagulation reach 80% at neutral pH. The coagulation of GO were strongly affected by the Al species in aqueous phase. GO-Al-HA complexes were the major mechanism of GO coagulation in the presence of HA.