New procedure for anoxic marine sediments remediation.

OFFER from Spain, reference: TOES20180607001, valid from 07-06-2018 untill 09-06-2019

  • Title:
    New procedure for anoxic marine sediments remediation.
  • Start date:
    7 juni 2018
  • End date:
    9 juni 2019
  • Summary:
    A Spanish university has developed a new anoxic marine sediment remediation system and a procedure that allows in situ transformation of soft, black, muddy sediment into a well-oxygenated, firmer sediment. It could be used for remediation of anoxic sediments on shallow beaches and materials extracted during port dredging that require elimination of anoxic conditions. Companies or public sector authorities interested in licensing or technical cooperation agreements are sought.
  • Description:
    The existence of uncontrolled and untreated anoxic muddy sediments on beaches is a well-known environmental problem within the decontamination and remediation sector. Such sediments negatively affect the tourism potential and public use of beaches, due to characteristics such as their foul smell, and reduce sediment biodiversity. The usual solution is limited to dredging and removal of anoxic sludge to somewhere else, normally to a landfill site or in the sea in areas away from the coast.

    Anoxic sediments frequently occur in areas that are heavily sheltered by ports or breakwaters, where lack of wave movement promotes deposition of fine particles and organic matter. This generates anoxic zones rich in organic matter, promoting the release of hydrogen sulphide (H2S) and the formation of ferrous sulphide (FeS); combined with the accumulated organic matter, this creates soft, shiny black sediments with a characteristic fetid odour.

    Furthermore, in recent decades a new environmental problem has emerged related to changes in benthic marine communities, whereby the replacement of some algae by others favours the deposition of fine particles and generates large amounts of organic matter in the sediment, increasing the anoxic conditions already present in these coastal areas.

    The studies carried out to date to address this problem, known as “air sparging” and “biosparging”, have focused on procedures for remediation of marine sediments in areas far from the coast and are aimed at eliminating contaminants such as petroleum hydrocarbons, mineral oils, halogenated substances, heavy metals and similar.

    In this sense, a Spanish university has developed a new anoxic marine sediment remediation procedure which consists of injecting oxygen-saturated sea water into the sediment in order to displace the anoxic/hypoxic pore water it contains.

    As a general rule, the concentration of dissolved oxygen in aquatic hypoxic/anoxic sediments is very low or null. Application of this procedure improves the content of dissolved oxygen in water, facilitating oxidation of organic matter and other reduced inorganic compounds that accumulate in the sediment, and thus enhancing the environmental conditions and potential for use of these sediments. In addition, oxidation helps eliminate substances toxic to the fauna that inhabit the sediment.

    The procedure entails the following sequence of steps (Figure 1):
    1. Sea water collection using a suction pump;
    2. Storage of collected sea water in a tank;
    3. Treatment in the tank of the collected sea water using a bubbling system to achieve a concentration of dissolved oxygen of between 6 and 9 mg O2/L at 20ºC;
    4. Pump-driven injection of oxygen-saturated sea water into a hydraulic circuit equipped with multiple nozzles inserted at different depths into the sediment to treat;
    5. Injection of oxygen-saturated sea water into the sediment using an injection sequence of between 90-180 minutes of rest and 50-70 minutes of injection.

    The injection nozzles form a key element of the system, and their number will depend on the number, diameter and length of the pipelines that constitute the hydraulic circuit used to inject the oxygen-saturated water into the sediment. They are opaque and rigid and are inserted into the sediment at depths of between 10 and 30 cm (see Figure 2).

    This procedure also offers the possibility of implementing an environmental monitoring plan and testing the efficiency of the method used by analysing changes in the pore water and the treated sediment.

    The university is looking for public sector authorities or companies dealing with sediments remediation interested in acquiring this technology for commercial exploitation through patent license agreements or technical cooperation agreements to use or adapt this technology to their needs.
Partner Sought
  • Type of Partnership Considered:
    License agreement, Technical cooperation agreement
  • Technical Specification or Expertise Sought:

    - Type of partner sought: Companies or public sector authorities
    - Specific area of activity of the partner: sea port management, dredging, sediments/beach remediation
    - Task to be performed: To commercially exploit this technology through:
    • Patent license agreements.
    • Technical cooperation agreements (Research and develoment projects) to use or adapt this technology to their needs/sector/sediments, etc.

    SME 11-50,SME <10,>500 MNE,251-500,SME 51-250,>500

  • Development stage:
    Under development/lab tested
  • IPR Status:
    Granted patent or patent application essential
  • Market keywords:
    Other leisure and recreational products and services
    Other pollution and recycling related
  • Technology keywords:
    Marine Science
    Remediation of Contaminated Sites
  • NACE keywords:
    Scientific research and development
    Tertiary education
  • Advantages and Innovations:
    The advantages of this remediation system with respect to other available decontamination techniques are:

    - Its lower environmental impact, since it does not involve the introduction of exogenous substances into the environament.
    - Its application achieves in situ transformation of soft, black, muddy, anaerobic sediment with a high organic matter content and a fetid odour into well-oxygenated, firmer sediment that has a much lower organic matter content and is no longer black or foul smelling.
    - It regenerates the sediment and enhances conditions for public and recreational use of the areas treated.
    - It improves the sediment’s capacity to host fauna, infauna, plant and algae communities.
    - Remediation of sediments extracted during port dredging would allow them to be deposited onto beaches without negatively affecting the ecosystem, since the procedure eliminates the organic matter and toxic substances responsible for the black colour and foul odour.
    - Even, it could also be used to prevent the need for dredging, which is more expensive and may even be impossible in certain locations for legal or technical reasons.
    - It could be used to immobilise certain heavy metals and other toxic inorganic compounds that accumulate in anoxic/hypoxic sediment and pore water. As a result, the sediment would no longer act as a sink for heavy metals present in the water.
    - It could be used as preventive measure to forestall the formation of anoxic sediments in a variety of environments (e.g. the open sea, reservoir and river beds, seagrass meadows and aquariums).

    While, the most innovative aspects of this technology are:
    • Type of contaminant to degrade: organic matter and inorganic substances generated in anoxic conditions;
    • Location: shallow beaches and calm waters where anoxic sediments accumulate;
    • Procedure and equipment required for remediation of muddy sediments: injecting oxygen-saturated sea water is a completely novel technique.
  • Type and Size of Organisation:
  • Already Engaged in Trans-National Cooperation
  • Year Established:
  • Turnover:
  • Country of origin:
  • Languages spoken
    • English
    • Spanish