Carbon (Nano) Sorbents for Environmental Remediation

The management of contaminated groundwater, surface waters and drinking water is a major issue both in the EU and globally, where recent (and historical) industrial, urban and commercial activities have led to the presence of elevated concentrations of a wide range of contaminants in surface- and ground-waters, adversely affecting the health of millions of people.

This has been recognised in a number of recent directives (e.g. the Water Framework Directive, the Groundwater Directive) aimed at protecting ground and surface water resources within the EU. However, despite much progress, groundwater and surface water quality is still highly variable across Europe, with many areas still highly contaminated. Due to the use of these waters for drinking water supply, this may have a number of health, as well as ecological and environmental, impacts.

CARBOSORB is a four year, 1.28 million Euro FP7 IAPP (Industry Academia Partnerships & Pathways) project, coordinated by the University of Brighton.

The aim of CARBOSORB is to develop and manufacture permeable composite filters in which carbon-rich nanoparticles (or nanoporous materials) will be embedded (and contained in a recyclable 3D structure), and use these as the basis of recyclable, high-performance water clean-up devices, for application in environmental and industrial sectors. It brings together a multidisciplinary consortium of specialists in different areas of environmental (geo)chemistry, nanotechnology and physical, analytical, synthetic, polymer and surface chemistry, working with a common aim of developing new and efficient methods of contaminant removal from surface and groundwaters, drinking waters and trade and industrial effluent.

Work performed since the beginning of the project has focused on four main areas: prototype development; analytical method development; physical and physico-chemical characterisation of the developed materials; and testing for adsorption of a range of key water contaminants. Further work in the second phase of the project will continue research and development in these areas, and also will examine the potential risks (if any) of device manufacture and use, and optimisation and scaling up of the prototype devices for real-world application.

The project team have worked closely to ensure strong transfer of knowledge between industry and academia, and also with external stakeholders such as water companies and existing technology providers, who have input (via networking and knowledge transfer events held within the CARBOSORB project at the Universities of Brighton and Barcelona, and during external meetings) key information on industry and performance requirements for upscaled devices. This is to ensure that prototype testing, characterisation and analytical strategies work themes have been carried out with future project deliverables in mind.



In terms of prototype development, a first generation of nano-composite materials targeted at key established and emerging water contaminants have been produced, using polymer and activated carbon 'scaffolds'. These 'scaffolds' either act as reactive media, or are used to hold a range of nanoparticles or nanoporous materials consisting of metal oxides, zeolites, carbon beads and fibres and other reactive materials. The different compositions are used to target different classes of contaminants, mainly organic in nature (although devices are also under testing for removal of heavy metals, phosphates etc).



A range of problematic contaminants have been targeted: oestrogens, trace pesticides and herbicides, etc., which are currently difficult to remove via conventional (e.g. granular activated carbon) treatment, or where nanocomposite devices potentially offer greater reactivity and capacity. Advanced chromatographic and other analytical techniques have been developed at the partner organisations to allow realistic measurement of trace contaminants (such as oestrogens and trace pesticides) at typical concentrations found in the environment, and to allow testing of the absorption capacity of the prototype devices produced in the project.

Initial characterisation work using a range of advanced analytical and imaging techniques indicates that the prototypes produced show low flow resistance, and that the device composition can be modified for different environmental applications and to target different contaminant groups. Adsorption tests indicate effective removal of a range of target contaminants, with prototype devices having a high adsorption capacity, e.g. adsorption capacity for the trace pesticide atrazine, onto a prototype device incorporating activated carbon beads into a PVA cryogel was in the order of 539 mg atrazine/g of carbon.

Busquets Santacana, Rosa, Kozynchenko, O.P., Whitby, Raymond, Tennison, S.R.and Cundy, Andrew (2014) Phenolic carbon tailored for the removal of polar organic contaminants from water: A solution to the metaldehyde problem? Water Research, 61. pp. 46-56. ISSN 0043-1354.

Whitby, R, Gun'ko, V.M., Korobeinyk, Alina, Busquets Santacana, R, Cundy, A Laszlo, K., Skubiszewska-Zieba, J.,Leboda, R.,Tombacz, E., Toth, I.Y., Kovacs, K. and Mikhalovsky, S (2012) Driving forces of conformational changes in single-layer graphene oxide ACS Nano, 6 (5). ISSN 1936-0851.

Voitko, K.V., Whitby, R, Gun'ko, V.M., Bakalinska, O.M., Kartel, M.T.,Laszlo, K., Cundy, A and Mikhalovsky, S (2011) Morphological and chemical features of nano and macroscale carbons affecting hydrogen peroxide decomposition in aqueous media Journal of Colloid and Interface Science, 361 (1). ISSN 0021-9797.

Whitby, R, Korobeinyk, Alina, Gun'ko, V.M., Busquets Santacana, R, Cundy, A, Laszlo, K., Skubiszewska-Zieba, J., Leboda, R.,Tombacz, E., Toth, I.Y., Kovacs, K. and Mikhalovsky, S (2011) pH-driven physicochemical conformational changes of single-layer graphene oxide Chemical Communications, 47 (34). ISSN 1359-7345.

Whitby, R.L.D., Fukuda, T., Maekawa, T., Mikhalovsky, S.V. and Cundy, A.B. (2010) Real-time imaging of complex nanoscale mechanical responses of carbon nanotubes in highly-compressible porous monoliths Nanotechnology, 21 (7). ISSN 0957-4484.