Aanleiding van het project
Sediment deposited by tide, river flows and currents need to be regularly removed by maintenance dredging. The volumes of dredged material have substantially increased over the last years. As maintenance dredging and relocation of these deposits can be highly expensive and inefficient, port authorities and governmental organizations seek alternative solutions to reduce siltation and at the same time guarantee safe navigation in navigational channels. In a previous TKI Deltatechnology project (DEL048), the return flow of dredged sediment from the sea to the port mouth was examined. This project is followed by another TKI Deltatechnology projects ‘Modellering lokale slibdynamiek en aanslibbing Maasmond (MoMa)’ (DEL089), that concerns the local sediment transport and sedimentation in the port itself. The Deltatechnology TKI projects (DEL101, DEL126) integrate the developed knowledge and brings new aspects, such as system knowledge, more in-depth modelling of fluid mud dynamics, innovative in-situ monitoring methods, water injection dredging and sediment trapping. The proposed TKI project is focused on applying developed modelling tools for testing natural gel barrier in designated port areas.
Doel van het project
The goal of the project is to assess the utility of a natural gel barrier for deflecting sediment depositions in navigational channels. The research will be conducted in 2 phases. Phase 1 will be dedicated to designing a gel by applying natural bio-flocculant agents and testing gel-sediment interactions in order to optimize gel’s rheological properties for applications in the port. A cost analysis, greenhouse gas emissions, circularity and environmental impact of designed product will be provided within this phase of the project. Using the rheological parameters of the gel found in phase 1 of the TKI proposal, in phase 2 detailed 3D CFD modelling of a zoomed in area round a gel barrier will be conducted to study whether such gel barrier could be kept at its place and used to reduce siltation. Three different gel barrier locations will be investigated for maximum 6 different conditions consisting of a combination of different gel characteristics and characteristic ambient flow conditions. Sensitivity analysis of important model choices will be carried out as well as tests to model the rheological gel behavior adequately. The developed knowledge will ultimately result in the reduction of maintenance costs and the reduction of greenhouse gas emissions from dredging activities. These advances will help set the PoR on the path towards achieving national and international climate targets. The project will contribute to strengthen the economical position of the Rotterdam port area as hub in the international corridor.
Omschrijving van de activiteiten
Q1 2021: kick-off of the project, starting Phase 1 Q2 2021: selecting bio-flocculants, defining a text matrix for gel tests in the laboratory Q3-Q4 2021: conducting laboratory experiments for designing an optimal gel for applications as a sediment barrier, making a business plan, greenhouse gas (GHG) emission analysis and environmental impact of the proposed solution Q3-Q4 2021: starting Phase 2 – a model study for investigating the impact of hydrodynamic conditions on a gel barrier, selecting potential port areas for applying gel barriers, optimizing the performance of the gel barrier with regards to sediment deposition in selected port areas Q1 2022: final reports and scientific publications. Workshop with the stakeholders for disseminating the results
Guideline on gel design, test matrix and sensitivity study (memo)
Report on optimal recipe for making a stable gel barrier, business plan, environmental impact and circularity, applying Kaumera Nereda® Gum for circular economy (Phase 1: final report)
Report on a modelling study of gel barriers efficiency in designated areas of navigational channels (Phase 2: final report)
The innovative aspects relate to designing an out-of-the-box generic solution, that can be used within a circular economy concept for controlling sediment deposition in ports and waterways. Currently available solutions for sediment barriers are made of constructional materials, thus a ship navigation through these barriers is impossible. We propose to test a natural gel as a sediment barrier. First, this innovative solution will allow ship navigation through a gel sediment barrier because the proposed gel will have weak strength and will recover its initial form after a ship passage. Second, a gel barrier can be more easily integrated into circular economy than standard barriers that are made of constructional material. The proposed bio-flocculant Kaumera Nereda® Gum is extracted from the sludge granules during Nereda® waste-water treatment process (https://kaumera.com/). By removing Kaumera from the purified sludge, 20-35% less sludge needs to be removed and processed. This has a positive effect on energy consumption and CO2 emissions. Our preliminary estimates show that Nereda plant can produces sufficient volumes of Kaumera Nereda® Gum for making a gel in the port. Finally, this study has a strong research component because the rheological behavior of gel is novel and modelling such flow type is challenging. If a gel barrier could be engineered such that it remains in its position it could be a very innovative manner of reducing siltation in a harbor with potential for many ports all over the globe.
RHDHV, Deltares, TU Delft, PoR, RWS
RHDHV will use the knowledge for developing further their flocculant agent Kaumera Nereda® Gum. PoR and RWS will use the guidelines for testing alternative flocculant agents if available. Deltares and TU Delft will integrate the knowledge in their knowledge base.
PoR, RWS, RHDHV, Deltares, TU Delft, technical universities, research institutes, waterboards (which are involved indirectly via Kaumera® and Nereda®)
PoR and RWS will use the knowledge for developing the product and integrate it in the port infrastructure. RHDHV and waterboards will use the findings for integrating Kaumera Nereda® Gum into a circular economy of their waste-water treatment processes. Deltares and TU Delft will integrate the knowledge in their knowledge base. Other technical universities and research institutes can use the findings to develop new knowledge on flocculation process.
Deltares, PoR, RWS, technical universities, research institutes, governmental institutions
Deltares will include rheology in their numerical models, PoR and RWS will utilize the knowledge for searching the optimal locations for installing gel barriers. The reported results and the data will be used by research institutes and governmental institutions for testing gel barriers in ports and waterways with heavy siltation.
TU Delft, Deltares, Technical universities, research institutes.
Deltares and TU Delft will produce scientific publications for disseminating knowledge.