Re-Suspension Technique for Improving Organic Rich Sediment-Water Quality in a Shallow Sea Area |
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| Authors: | Masaharu Fukue Koji Uehara Yoshio Sato Catherine Mulligan |
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| Institution: | 1. Tokai University , Shizuoka , Japan fukue@scc.u-tokai.ac.jp;3. Aomi Construction , Tokyo , Japan;4. Tokai University , Shizuoka , Japan;5. Concordia University , Montreal , Canada |
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| Abstract: | The re-suspension method consists of (1) dispersion of the sediment by air-water jets, (2) pumping of the suspension (small particles and organic matter), (3) settlement in a tank, (4) filtration and (5) disposal of solids (followed by incineration in this case). The pilot test was performed to clean up an area of 3000 m2. The dispersed depth of the bottom was approximately 50 cm. The time spent for the work was two weeks. The amount of re-suspended solid removed from the bottom was about 8 tonnes in dry mass. Since the solids contain high concentrations of chemical oxygen demand (COD), total phosphorous (T-P), total nitrogen (T-N) and sulfides, the remaining sediment was considerably improved. Quantitative analyses showed that the full-scale implementation would enable the removal of about 10% of the re-suspended solids, and reduce COD by 95%, T-P by 50%, T-N by 100% and sulfide by 75% for re-deposited sediments in comparison to the original sediments. |
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| Keywords: | COD nutrients re-suspension sediment sulfides |
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