Retention of heavy metals and poly-aromatic hydrocarbons from road water in a constructed wetland and the effect of de-icing

Type
Article

Authors
Tromp, Karin
Lima, Ana T.
Barendregt, Arjan
Verhoeven, Jos T.A.

KAUST Grant Number
KUK-C1-017-12

Date
2012-02

Abstract
A full-scale remediation facility including a detention basin and a wetland was tested for retention of heavy metals and Poly-Aromatic Hydrocarbons (PAHs) from water drained from a motorway in The Netherlands. The facility consisted of a detention basin, a vertical-flow reed bed and a final groundwater infiltration bed. Water samples were taken of road water, detention basin influent and wetland effluent. By using automated sampling, we were able to obtain reliable concentration averages per 4-week period during 18 months. The system retained the PAHs very well, with retention efficiencies of 90-95%. While environmental standards for these substances were surpassed in the road water, this was never the case after passage through the system. For the metals the situation was more complicated. All metals studied (Cu, Zn, Pb, Cd and Ni) had concentrations frequently surpassing environmental standards in the road water. After passage through the system, most metal concentrations were lower than the standards, except for Cu and Zn. There was a dramatic effect of de-icing salts on the concentrations of Cu, Zn, Cd and Ni, in the effluent leaving the system. For Cu, the concentrations even became higher than they had ever been in the road water. It is advised to let the road water bypass the facility during de-icing periods. © 2011 Elsevier B.V.

Citation
Tromp K, Lima AT, Barendregt A, Verhoeven JTA (2012) Retention of heavy metals and poly-aromatic hydrocarbons from road water in a constructed wetland and the effect of de-icing. Journal of Hazardous Materials 203-204: 290–298. Available: http://dx.doi.org/10.1016/j.jhazmat.2011.12.024.

Acknowledgements
We are indebted to Gerard Rijs, John Schellings, Paul Flapper, Gerard de Blok, and Jan den Hertog of different agencies of Rijkswaterstaat (Ministry of Transport and Water Infrastructure) for initiating this project and for their continuous interest in the research. The study was supervised by Dr. Johannes Tolls and Dr. Joop Hermens of IRAS, Utrecht University. Gerrit Rouwenhorst and Paul van der yen of the Department of Biology, Dr. Ben van Os of the Department of Geoscience of Utrecht University and Erik van Vilsteren of Deltares helped with the chemical analyses. Rijkswaterstaat Noord-Holland provided the funding for this research project. That agency also was responsible for constructing the wetland facility and for maintenance. The data collection and data interpretation was made independently by the authors. This publication was partially supported by Award No KUK-C1-017-12, made available by King Abdullah University of Science and Technology (KAUST) to the second author.

Publisher
Elsevier BV

Journal
Journal of Hazardous Materials

DOI
10.1016/j.jhazmat.2011.12.024

PubMed ID
22226719

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