Graphene Oxide in Environmental Remediation Process

Since the water crisis is facing, purification methods and removal technology are the object of discussion. Carbon-based materials are largely employed as filters and in particular graphene oxide is considered for its exceptional physical chemical properties as a good candidate for the fabrication of innovative devices.

The chapter gives an overview of the most important synthetic methods to produce graphene oxide via wet chemistry. Brodie-Staudenmaier-Hummers and free-water based approaches are reported and where it is considered the influence of synthesis on the graphene oxide structure. Physical chemical and morphological characterisations are described in the second part of the chapter. In the last section, details of theoretical calculation and modelling of graphene oxide structures are presented.

Applications of smart nanomaterials are expected to impact many aspects of life and promoting a substantial and advanced change in technologies. However, recently the toxicity of these very promising materials and their environmental impact has been questioned. Graphene oxide is not yet regulated by a specific normative, thus the parent definition for nanomaterials is adapted. This chapter presents the normative and regulations on the nanomaterials with particular attention for the EU area. Because of a legislative framework is not yet presented or incomplete, guidelines and definitions support normative in view of auxiliary results from scientific progress on smart nanomaterials. In addition, a provisorily ISO technical document is approaching to define and standardize the producers to work with a nano-object. As graphene oxide is a novel nanomaterial, environmental aspects, connected to its employment, are now limited and further scientific understanding is needed to establish the eventual health and ecosystem risks.

In this chapter the remediation of water by means of graphene oxide is reported. The advantage of the use of this material is based on the amphiphilic character of graphene oxide which allows to remove inorganic and organic molecules at nanoscale range. In a remediation process, graphene oxide can be implemented as free-standing, functionalized or composite material, as well as, in solid or liquid phase. Lamellar or foam arrangement and graphene oxide dispersion are differently used to produce membrane or 3D structures to efficiently remove a broad range of natural and synthetic molecules/ions with high sensitivity. Thus, graphene oxide opens an unconventional scenario for nanopurification of industrial wastewater which are contaminated with hazardous molecules. This subject is a relatively new topic and we are witnessing its development as a feasible nano-adsorbent/removal material. The most updated progress in this field is reported and categorized.

The graphene oxide is explored as a smart material in the context of environmental remediation. This material possesses a wide potential in removal pollutions from contaminated water systems. The advantage of graphene oxide consists of an affinity for inorganic and organic contaminants and placing graphene oxide in a predominant position in comparison with conventional adorbant/removal materials.