Water Science & Technology: Water Supply Vol 1 No 2 pp 27–35 © IWA Publishing 2001
Change in the water quality of industrial channels due to resuspension of
sediments contaminated with heavy metals
A Degtiareva* and M Elektorowicz**
*
Concordia University, Department of Building,
Civil and Environmental Engineering, 1455 Blvd de Maisonneuve West,
Montreal, Quebec, Canada, H3G 1M8, (Email: mariae@civil.concordia.ca)
**
Concordia University, Department of Building,
Civil and Environmental Engineering, 1455 Blvd de Maisonneuve West,
Montreal, Quebec, Canada, H3G 1M8, (Email: mariae@civil.concordia.ca)
ABSTRACT
Industrial channels were used extensively during the two previous centuries
and have become heavily contaminated. This study investigates possible water
quality changes in the Lachine Canal (Montreal) due to the release of heavy
metals (Cd, Ni, Zn and Pb) into the water column during resuspension of
anoxic sediments subjected to potential remediation. This release can be
initiated by dredging activities for sediment removal. Equilibrium in the
water from the Lachine Canal has been calculated using the program EQUILIB
from the software FACT. The speciation of heavy metals in the water column
was calculated with and without a solid phase before and after possible
dredging. Speciation of heavy metals in pore water of anoxic sediments has
been calculated, taking into account that corresponding sulfides are the
solid phases controlling their solubility. The concentration of heavy
metals under anoxic conditions considered could decrease by 8 orders of
magnitude. The impact of various scenarios in the area of concern was reviewed from an ecotoxicological perspective. Dredging can possibly
change the redox and acid–base conditions in the water column. The
impact of dredging will be less if sediments contain calcium. Dredging
can lead to an increase in the concentration of heavy metals in the
water column and a change of metal speciation.
Full article (PDF Format)
PAY-PER-VIEW: Buy this article for £20.00 (IWA MEMBER PRICE: £15.00)
|
