Study of remediation of heavy metals contaminated sediments with hydrothermal technology and sediment washing facilitated by chelating agents

• Main Author: Wong, Angeline Shou Yee.
• Other Authors: Wang Jing-Yuan
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/53855
• Institution: Nanyang Technological University

This report examines the efficiencies of heavy metals removal of marine sediments by sediment washing and the impact of hydrothermal treatment on heavy metals removal in dredged marine sediments. The targeted heavy metals were Zn, Cu, Pb, Cd, Cr, Ni and As. In this study, short contact periods of 2, 4 and 8 hours, and low EDTA concentrations of 0.005 M, 0.01 M and 0.02 M were used in sediment washing and in hydrothermal treatment. Under low EDTA concentrations and short contact times for sediment washing, the maximum removal of Pb, Ni and Zn were 48%, 30% and 26% respectively. For Cd, its removal was highest (11%) when no EDTA was used for washing. For Cu, Cr, Ni and As, their removals were negligible. Hydrothermal treatment under varying conditions with short contact time and low EDTA concentrations were then carried out to find out the effects of hydrothermal treatment on heavy metals. Hydrothermal treatment has a greater impact on removal of Pb and Zn and Ni, has a moderately low impact on Cu and has the least impact on As, Cr and Cd. Depending on the hydrothermal treatment method, removal of heavy metals by EDTA may be higher or lower in comparison to sediment washing alone.