Development of an environmental management framework for sustainable reuse of Malaysian dredged marine sediments

Dredged marine sediments (DMS), product of dredging activities, is classified as a waste and usually disposed off at sea. However, certain DMS is contaminated and sea disposal can significantly affect water quality and marine ecosystem. This can be mitigated and controlled by appropriate DMS managem...

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Bibliographic Details
Main Author: Shahri, Zarina
Format: Thesis
Published: 2016
Subjects:
Online Access:http://eprints.uthm.edu.my/8866/
http://eprints.uthm.edu.my/8866/1/ZARINA_SHAHRI.pdf
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Summary:Dredged marine sediments (DMS), product of dredging activities, is classified as a waste and usually disposed off at sea. However, certain DMS is contaminated and sea disposal can significantly affect water quality and marine ecosystem. This can be mitigated and controlled by appropriate DMS management. The aim of this study is to develop an environmental management framework for sustainable reuse of Malaysian DMS. The DMS was retrieved from four dredging sites: Lumut, Melaka, Tok Bali and Pasir Gudang. There are six components in this framework: physical properties, chemical properties, biological properties, treatment, beneficial uses and disposal. The framework begins with DMS physical properties. Assessment DMS with > 50 % of particles with sizes less than 2 mm are subjected to the chemical and biological properties. DMS dominated by coarse particles are suitable for beneficial reuse without further treatment. Fines with contaminant levels below the permitted levels could be directly reused, while those with high levels would undergo treatment. After treatment, those with reduced contaminant levels fulfilling the stipulated limits would be considered suitable for reuse. Treated DMS with residual high contaminant levels exceeding the limits would be assigned to suitable disposal sites. Laboratory experiments were carried out to identify the physical, chemical and biological properties according to British Standards (BS 1377 and BS 6068). All the DMS were mainly silt and clay. There were six heavy metals detected namely arsenic, chromium, copper, lead, nickel and zinc in all DMS. Based on Sediment Quality Guidelines (SQG), As, Cr, Pb and Ni in Lumut DMS exceed the TEL values. Arsenic and nickel concentration in Melaka DMS was exceeded both guideline, ERL and TEL. The concentration of Cr, Cu and Pb in Melaka was also higher than TEL limits. The DMS of Tok Bali contained two trace metals (As and Pb) that higher than ERL and TEL. The Pasir Gudang DMS was high concentration of As and Cr. From the biological property assessment test, Serratia plymuthic, Vibrio alginolyticus and Corynebacterium genitalium were detected in Lumut DMS, while Serratia marcescens, Vibrio vulnificus, Edwardsiella tarda, Bacillus cereus and Escherichia coli were in Melaka DMS and 14 bacteria detected in Tok Bali DMS. All the inhabitant bacteria were classified as Risk Group level 2. Based on the results obtained, treatment is necessary for all DMS prior to consider for reuse or disposal.