Electrodialytic removal of Cd from biomass combustion fly ash: A new approach for sustinable re-cycling of bio ashes

Anne Juul Pedersen, Lisbeth M. Ottosen, Peter Simonsen, Terkel Christensen

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    Abstract

    Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion fly ashes was studied. Four fly ashes were investigated, originating from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. One of the straw ashes had been pre-washed and was obtained suspended in water, the other ashes were obtained naturally dry. The initial Cd concentration in the ashes varied between 8.8 mg Cd/kg DM (co-firing ash) and 64 mg Cd/kg DM (pre-washed straw ash), and pH varied from 3.7 to 13.3. In spite of large differences in ash characteristics, the electrodialytic remediation experiments indicated a good remediation potential for all four ashes. Final Cd concentrations below 2.0 mg Cd/kg were reached in all ashes within 14 days of remediation and legislative requirements were met. After further optimization of the remediation process on the pre-washed straw ash, limiting concentrations were reached after only 48 hours of remediation. Hence the potential of the process seems very promising.
    Original languageEnglish
    Title of host publicationSecond World Biomass Conference. Biomass for Energy, Industry and Climate Protection : Proceedings of the World Conference held in Rome, Italy, 10-14 May 2004
    EditorsW. P. M. Van Swaaij
    VolumeII
    Publication date2004
    Publication statusPublished - 2004
    Event2nd World Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection - Rome, Italy
    Duration: 10 May 200414 May 2004
    Conference number: 2

    Conference

    Conference2nd World Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection
    Number2
    Country/TerritoryItaly
    CityRome
    Period10/05/200414/05/2004

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