Understanding metal concentration and speciation in motorway runoff

ABSTRACT

Although highway runoff has historically been extensively studied, the increasing complexity of stormwater management means that there are still significant gaps regarding the reduction of soluble metals. The work reported in this paper addresses these challenges by analysing the presence and behaviour of iron, copper and zinc in runoff from junction 24 of the M1 motorway in the UK (peak traffic flow: 30,000 vehicles per hour) and comparing it with other urban sources of metals found in the same catchment (a local brook and sewage treatment works). The sampling site included an interceptor and a treatment lagoon and the event monitoring indicated a trend by which the metals did not change their concentration or particulate soluble proportion immediately, hence showing that pre- and post-storm conditions are important factors when analysing the solubility of metals and their behaviour. The data provided further evidence of the important influence of storm characteristics on metal concentrations in highway runoff, in particular the effects of an antecedent dry weather period (ADWP). In addition, this study also helped us to better understand how the release of sodium the application of de-icer for road maintenance in winter affects the availability of zinc.

GRAPHICAL ABSTRACT

KEYWORDS:

• ADWP
• de-icer application
• highway runoff
• soluble metals
• SuDS

Acknowledgements

This research was supported by Loughborough University and partially supported by SUE ‘Vodokanal of St. Petersburg’. The authors thank Mr Geoff Russell and Mrs Jayshree Bhuptani for assistance with laboratory and field support. The authors are immensely grateful to Prof David Butler, University of Exeter, for his comments on an earlier version of the manuscript. The authors also recognise the fact that without the support provided by Mr David Chapman, Mr Dhan Tagie, Mr Dmitry Zakharov the publication of this paper would not have been possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by Loughborough University and partially supported by SUE ‘Vodokanal of St. Petersburg’.