Sihwa
A case of washing and sorting highly contaminated dredged sediment.
Treating highly contaminated dredged soil
to compliant levels through washing and separation.
At the Sihwa detention-basin and industrial-complex main-canal sites, highly contaminated dredged soil was washed and separated through Soil Washing to reduce contaminant concentrations.
Dredged soil was separated by particle size and the recovered fraction tested for contamination and reuse potential, reducing disposal burden and improving treatment reliability.
Contaminated-soil treatment site
Detention Basin & Canal Sediment Treatment
Sihwa Detention Basin Section 2
Mar–May 2003
Average Contaminant Reduction
Highly contaminated dredged soil is classified for on-site treatment, with washing and separation targeting compliant contaminant levels.
Dredged soil is processed with wash water to separate gravel, sand and sludge while reducing contaminant concentrations.
After washing, the recovered soil fraction is tested to establish suitability for reuse.
| Parameter | Dredged Soil | Recovered Soil | Reduction |
|---|---|---|---|
| Cadmium | 0.33 | 0.020 | 93.9% |
| Copper | 7.896 | 0.576 | 92.7% |
| Arsenic | 0.86 | 0.45 | 47.6% |
| Mercury | 0.011 | 0.002 | 81.8% |
| Lead | 13.74 | 1.3 | 90.5% |
| Hexavalent Chromium | 0.418 | 0.011 | 97.4% |
| Oil Content | 8% | 1.25% | 84.0% |
| Average | - | - | 87.5% |
