Designing natural gel barriers for controlling sediment deposition in ports
Port authorities and governmental organizations are actively searching for
new innovative solutions for maintaining ports and waterways more
efficiently. One of possible solutions is developing new port maintenance
strategies (DEL 101, DEL 126). Another possible solution is controlling
sediment deposition by installing sediment deflection barriers. However,
the sediment barriers are expected to meet the following requirements:
1 – be efficient in reducing siltation in navigational channels
2 – be environmentally friendly and conform to circular economy principles
3 – guarantee safe navigation
The main objective of the proposed research is to develop a natural
sediment barrier by utilizing a biological flocculating agent in specific areas
of the port to promote the accumulation of sediment forming a gel in
designated areas. Several types of flocculants will be tested. The most
promising candidates are Alginates and Alginate Like Exopolymers (ALE)
which comply to these requirements. One of the potential candidates is
Kaumera Nereda® Gum, which is a new bio-based raw material that is
extracted from the sludge granules that form during the Nereda®
The proposed research consists of the lab tests for optimizing gel
properties and Delft3D study for studying the impact of hydrodynamic
conditions on a gel barrier
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.
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.
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
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.
Alle partijen krijgen alle resultaten van het Project ter beschikking. De resultaten van de samenwerking kunnen breed verspreid worden. Partijen kunnen over deze resultaten vrijelijk publiceren. De resultaten zullen volledig openbaar beschikbaar zijn, met uitzondering van ter beschikking gestelde achtergrondkennis.
De informatie over dit project wordt kenbaar gemaakt via de website van de TKI Deltatechnologie (projectbeschrijving) en de projectwiki van Deltares (projectvoortgang en resultaten).
Na de datum waarop deze Overeenkomst in werking is getreden, maar uiterlijk tot een jaar voor de beoogde datum waarop het Project zal zijn voltooid, kunnen ondernemers en/of onderzoeksinstellingen, die op het terrein van het relevante subsidieprogramma van het TKI werkzaam zijn alsnog als Partij toetreden. Een later toetredende Partij zal een nader overeen te komen bijdrage in kind en/of in cash moeten leveren die in redelijke verhouding staat tot zijn relatief aandeel in het Project na toetreding. De overige Partijen ontvangen vervolgens naar rato een terugbetaling en/ of gedeeltelijke vrijstellingen van hun nog te leveren bijdrage in kind, voor zover niet besloten wordt de bijdrage van de later toetredende Partij aan het projectbudget toe te voegen.