An experimental study on leaching characteristics from dredged sediments

Use of dredged sediments is one of the important subjects for marine environmental problem. This study proposes to use dredged organic sediments as fertilizer and manure in the sea. To examine quality of dredged sediments, leaching tests were performed using the Orido bay sediments and artificial seawater. The sediments were dried or burned at various temperatures (Natural, 60, 110, 300, 800 and 1000 deg C), before the leaching tests. The pH value of artificial seawater used was adjusted 8.05 with buffer solution of 10%-NH4Cl. The experimental results showed that the redox potential of sediments increased with temperature used. The nutrients and heavy metals contained in the sediments were leached, depending on the temperature used. It was found that there was an optimum temperature for the maximum amount of leachate.