Characterization of dredged sediments: a first guide to define potentially valuable compounds – the case of Malmfjärden Bay, Sweden
<p>Millions of tons of bottom sediments are dredged annually all over the world. Ports and bays need to extract the sediments to guarantee the navigation levels or remediate the aquatic ecosystem. The removed material is commonly disposed of in open oceans or landfills. These disposal methods...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-09-01
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| Series: | Advances in Geosciences |
| Online Access: | https://www.adv-geosci.net/49/137/2019/adgeo-49-137-2019.pdf |
| Summary: | <p>Millions of tons of bottom sediments are dredged annually
all over the world. Ports and bays need to extract the sediments to
guarantee the navigation levels or remediate the aquatic ecosystem. The
removed material is commonly disposed of in open oceans or landfills. These
disposal methods are not in line with circular-economy goals and
additionally are unsuitable due to their legal and environmental
compatibility. Recovery of valuables represents a way to eliminate dumping
and contributes towards the sustainable extraction of secondary raw
materials. Nevertheless, the recovery varies on a case-by-case basis and
depends on the sediment components. Therefore, the first step is to analyse
and identify the sediment composition and properties. Malmfjärden is a
shallow semi-enclosed bay located in Kalmar, Sweden. Dredging of sediments
is required to recuperate the water level. This study focuses on
characterizing the sediments, pore water and surface water from the bay to
uncover possible sediment recovery paths and define the baseline of
contamination in the water body. The results showed that the bay had
high amounts of nitrogen (170–450 <span class="inline-formula">µ</span>g L<span class="inline-formula"><sup>−1</sup></span>), leading to
eutrophication problems. The sediments mainly comprised small size
particle material (silt, clay and sand proportions of 62 %–79 %, 14 %–20 %, 7 %–17 %, respectively) and had a medium–high level of nitrogen
(7400–11 000 mg kg<span class="inline-formula"><sup>−1</sup></span>). Additionally, the sediments had little presence
of organic pollutants and low–medium concentration of metals or metalloids. The
characterization of the sediments displays a potential use in less sensitive
lands such as in industrial and commercial areas where the sediments can be
employed as construction material or as plant-growing substrate (for
ornamental gardens or vegetation beside roads).</p> |
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| ISSN: | 1680-7340 1680-7359 |