Elemental chemistry of fugitive dusts from quarries and associated sites

Fowler, Mike; Datson, Hugh; Williams, Ben

Abstract

Fugitive dust from quarrying and related extractive industry activities is a long-standing and intractable problem. Attempts to control emissions are directed by legislation and informed by statutory guidance, within the overall context of national and international air quality strategies. In many cases, local monitoring is a prerequisite for efficient development of dust suppression. In cases of dispute or of particular concern, it is often necessary to confidently attribute problem dust to one or more local source(s) – in effect to answer the fundamental question: whose dust is it? This contribution describes a method of dust source attribution developed by DustScan Ltd, which combines a simple and cost-effective technique for collecting ambient dust by direction, with multi-element analysis by plasma spectrometry. DustScan is a passive system for monitoring fugitive dust 360° around a replaceable sampling head. It uses a transparent, permanent adhesive, ‘sticky pad’ on a 70 mm diameter cylindrical monitoring head. Measurement of dust coverage on the sticky pads after monitoring uses a computer-based scanning system and bespoke software. The pattern of dusting on the sticky pad indicates the direction and scale of potential dust nuisance by direction. Given this information, samples may be taken according to suspected dust source, and subjected to a range of geochemical analyses including acid dissolution (HF-HNO3) prior to analysis by ICPAES or ICP-MS. Rigorous blank correction procedures are essential to account for metallic components of the sticky pads themselves, but good results are obtained for a range of elements including Cu, As, Cd and Pb. Careful assessment of the data often allows sourcespecific elemental criteria to be established; the elemental fingerprints of dust type. In the simplest of cases, this is sufficient to identify the source of a problem dust, but more commonly some form of mixture deconvolution is required. Various intuitive graphical techniques have been successful in small-scale studies, but multivariate statistics and least-squares mass balance methods provide powerful tools for source attribution as the site database increases. Examples of the application of such techniques to a variety of extractive industry sites demonstrate the utility of the methods in the extractive industries and elsewhere.

• Publication Date: Jan 1, 2012
• Journal: Proceedings of the 16th Extractive Industry Geology Conference
• Print ISSN: 2055-3250
• Peer Reviewed: Peer Reviewed
• Pages: 146-159
• Book Title: Proceedings of the 16th Extractive Industry Geology Conference
• ISBN: 9780955234630
• Keywords: EIG, environmental forensics, quarries, ICP-MS, ICP-AES, passive sampling
• Public URL: https://uwe-repository.worktribe.com/output/950584
• Publisher URL: http://static1.squarespace.com/static/54199a46e4b05afa19b4e68c/t/54577774e4b06ff246527a00/1415018356761/Fowler+146-159.pdf
• Contract Date: Jan 1, 2012