Mechanistic insight into efficient removal of tetracycline from water by Fe/graphene

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2019-10, Vol.373, p.821-830
• Main Authors: Alatalo, Sara-Maaria, Daneshvar, Ehsan, Kinnunen, Niko, Meščeriakovas, Arūnas, Thangaraj, Senthil K., Jänis, Janne, Tsang, Daniel C.W., Bhatnagar, Amit, Lähde, Anna
• Format: Article
• Language: English
• Subjects: Adsorption; Carburization; Graphene; Tetracycline; Water treatment; Zero-valent iron
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2019.05.118

•Carbothermal reduction for the synthesis of zero valent iron-graphene composite.•Stable Fe0 under air, high temperature, minor oxidation in water.•Self-cleaning potential prolonging the adsorption of tetracycline.•No degradation products of tetracycline observed caused by Fe0. The release of pharmaceuticals into aquatic environments is a serious concern due to the persistence and potential health and environmental risks of these substances. Surface and ground waters are polluted with a variety of pharmaceuticals due to insufficient water purification processes in wastewater treatment plants. Here, we report a simple procedure for the production of composite materials consisting of zero-valent iron embedded in few-layer graphene, Fe/graphene, through induction annealing at 900 °C. Zero-valent iron was observed as magnetic 1 µm-sized crystals embedded in the graphene matrix appearing in the α- and γ-forms. This Fe/graphene composite was applied as an adsorbent for the removal of tetracycline (a pharmaceutical) from water. The Fe/graphene showed high tetracycline removal efficiency (422 mg/g) under optimized conditions. Furthermore, the Fe/graphene possessed self-regenerating features prolonging its lifetime and total removal capacity up to 660 mg/g, thus making it a potential material for removing tetracycline from water.