Research

At Exo Environmental we invest in research and development in our own expertise and work collaboratively with a variety of specialist bodies, research institutions and working groups, in order to provide innovative solutions to our clients’ needs. Our work is underpinned by the PIANC philosophy of ‘Working with Nature’. This focuses our project objectives, taking a holistic, ecosystem-based approach to create win-win solutions rather than simply minimising ecological harm. We aim to balance economic, societal, environmental and engineering factors to optimise design with positive gains from project conception to completion and beyond.

Below are just some examples of research and development projects that Exo Environmental is involved with. Most of our work is presented during seminars and conference and sometimes published in academic journals. Yet some work is confidential and developed behind the scenes.

GeoBlocks

Sediment solidification, sediment stabilisation
  • Geo-blocks are geo-engineered structures comprised of a base aggregate that is stabilised through one or a combination of physical, chemical or mechanical methods and can be used as an alternative to existing hard-engineering coastal defences (e.g. rock armour).
  • Exo Environmental is engaged in research into the suitability of using dredged sediment to produce geo-bocks, dependent on the site-specific physio-chemical properties of the dredged sediments and optimisation of the binding method.
  • This innovative approach to dredged sediment, based on an underlying proven technology, has the potential to turn a waste material into a viable product with associated economic and environmental benefits.

Geotextile bags

Salhouse, beneficial reuse
  • Transport and disposal of dredged material is a significant cost of dredging projects, both economically through direct financial outlay and environmentally, due to CO2 emissions and disruptions during transport and the impact of disposal on receptor sites.
  • Geotextile bags can be employed to address these issues in certain instances. By retaining dredged material within these structures, the material can be dewatered, stabilised and stored on site or beneficially reused. This reduces the need for costly transportation and minimises environmental impact in the disposal process.
  • Exo Environmental specialise in the use of geotextile bags as solutions to dredging project requirements, providing environmental benefits whilst maximising economic gains. Please see our Waterside Marina case study as an example.

EU Hemp in Bio-Engineering

Hemp Fabric, bio-engineering
  • Natural hemp fibre can be a viable alternative to jute and coir (coconut) in the use of geotextiles and biocomposite materials. In the context of engineering based geotextiles, hemp is under represented, with a paucity of high quality data relating to its use in engineering projects such as erosion control and under layers.
  • Exo Environmental together with European hemp producers is investigating the potential for hemp fibres to be used in bio-engineering in marine and freshwater environments.

Retaining Structures for Habitat Creation

Brushwood Faggots, brushwood fascines, polers
  • The success of habitat creation and restoration projects in both freshwater and marine environments, is heavily dependent on being able to stabilise the newly deposited material. Consolidated sediment reduces the impact of erosion and provides a more suitable substrate for biological colonisation to occur, which in turn, further stabilises sediments and allows the generation of established habitats. Retaining structures can be used during the disposal process in order to facilitate this consolidation and settlement process.
  • At Exo Environmental, we are actively developing traditional methods whilst researching pioneering solutions in order to bring together our experience and knowledge of sediment and water management, to provide innovative and site-specific project design. This ranges from geo-block hard engineering in high energy environments, to hybrid systems comprised of locally sourced materials employed using both traditional and modern methods.

Geosynthetic Fabrics in the freshwater environment

Geosynthetic Research in freshwater habitats Tim Foo photo
  • In partnership with Tencate Geosynthetics, the University of East Anglia and Tim Foo, Environmental Sciences Graduate, Exo Environmental is testing fabrics in a freshwater environment. This works follows earlier studies carried out in the marine environment.
  • The fabrics are examined on the ecological potential for biofilms, vegetation and macro-invertebrates. This work is carried out with the help of Pulse Amplitude Modulated (PAM) Fluorometry, to assess the biomass during regular intervals.
  • The fabrics are examined three separate sites, taking into account some environmental and spatial variability. The study is aimed to support aquatic restoration projects in selecting fabrics with the most ecological potential, parallel to their technical specification.

Geosynthetic Fabrics in the Marine Environment

Sediment Solutions Cover Photo
  • Alongside Tencate Geosynthetics and the University of East Anglia, Exo Environmental is investigating the ecological potential of geosynthetic fabrics in trapping sediments and suitability for micro-algae, thereby providing a substrate for biological colonisation.
  • Microbial biofilms improve the stability of sediment particles, playing an important role in the accumulation and accretion of intertidal and wetland habitats and facilitating the subsequent succession of higher plants.
  • This approach provides a bioengineering solution, which with time, can aid sediment consolidation and prevent erosion, reduce maintenance costs and result in an overall increase in biodiversity health of the system.

Productive Dredging Depots

Reed Canary Grass
  • Dredging depots and landfill sites often have only one purpose, the safe storage of dredged material. In the UK approximately 28 – 57 million wet tonnes of dredged material are stored in licensed sites each year. Exo Environmental carried out a study into Reed Canary Grass (Phalaris arundinacea) as a biogas feedstock, grown on these desolate sites.
  • The study suggests that Reed Canary Grass and other related crops would be highly productive on these sites. Reed Canary Grass (RCG) used as feedstock for biodigesters and converted to methane could provide a clean sustainable alternative to natural gas. Additional benefits are bioremediation processes that occur because of the dense oxidising rhizome and root systems. However our research showed that the industry is working on a scale where RCG could not completely replace the other feedstocks. Due to the incompatibility of using various feedstocks at once, the industry is currently resistant to moving towards RCG.
  • For the above reasons, when assessed in isolation, Reed Canary Grass doesn’t offer a strong enough business case. However when assessed holistically, benefits in and above the production of methane significantly improve the potential of the technology and could be applied to dredging depots and landfill sites to turn them from contaminated dead spots to a source of viable products.

Beach Nesting Birds

Little Tern Nest
  • In partnership with the RSPB, Exo Environmental has developed artificial nesting platforms for beach nesting birds. A particular focus is on Common Terns (Sterna hirundo) and Little Terns (Sterna albifrons), unique migrating seabirds that visit the UK every summer.
  • The artificial nesting platforms are made out of stabilised dredged sediment, based on a concept developed in our GeoBlock R&D. By replacing increasingly scarce resources such as river sand and crushed stone aggregate with abundant waste sediment, the GeoBlock approach creates a circular economy. This technology benefits the picky and declining seabirds whilst reducing the environmental impact compared to alternative nest solutions, mostly based on plastic.
  • In spring 2019, numerous artificial nests were placed at 4 different sites on the East Anglian coast line for testing. In the first month beach nesting birds selected these elevated artificial nests as prime nesting grounds. We are anticipating dozens successful nests, directly linked to our R&D, this summer breeding season. The monitoring is providing vital data for the improvement of the design and the further roll-out in 2020.

Plastics

Microplastics Zoomed In Image
  • Plastic pollution has reached global epidemic proportions. Due to the nature of the surveying activities undertaken by Exo Environmental in rivers, lakes, estuaries and harbours, we come across huge amounts of plastic items, such as bags, wrappings, cups, bottles and wet wipes (albeit not necessarily plastic based). These obvious culprits are the visual plastics. It is at the micro scale however, where the true problem lies.
  • Micro plastics in sediment and water are an insurmountable problem that is relatively invisible, however it is greatly detrimental to our ecosystems and food chains. Based on a study carried out in the University of Ghent, an average European consumes up to 11,000 pieces of plastic in their food per year, out of which about 60 pieces are directly absorbed and accumulate in the body. Micro plastics also often contain contaminants, which can potentially cause serious health issues and have been linked to cancer. Exo Environmental is co-developing sampling methods to study micro-plastics in sediment and water that is aimed at the understanding of the impact and possible measures to manage this global problem.
  • We aim to offer our clients a sampling and testing method to determine the level of microplastics in their sediments and consult on how to tackle the problem. Contact us to find out how we can help you lower the plastic pollution on your land.

If you have any queries at all, please don’t hesitate to get in contact with us: enquiries@exo-env.co.uk.

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