A Rapid, Accurate, and Efficient Method to Map Heavy Metal-Contaminated Soils of Abandoned Mine Sites Using Converted Portable XRF Data and GIS

Abstract

The use of portable X-ray fluorescence (PXRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) increases the rapidity and accuracy of soil contamination mapping, respectively. In practice, it is often necessary to repeat the soil contamination assessment and mapping procedure several times during soil management within a limited budget. In this study, we have developed a rapid, inexpensive, and accurate soil contamination mapping method using a PXRF data and geostatistical spatial interpolation. To obtain a large quantity of high quality data for interpolation, in situ PXRF data analyzed at 40 points were transformed to converted PXRF data using the correlation between PXRF and ICP-AES data. The method was applied to an abandoned mine site in Korea to generate a soil contamination map for copper and was validated for investigation speed and prediction accuracy. As a result, regions that required soil remediation were identified. Our method significantly shortened the time required for mapping compared to the conventional mapping method and provided copper concentration estimates with high accuracy similar to those measured by ICP-AES. Therefore, our method is an effective way of mapping soil contamination if we consistently construct a database based on the correlation between PXRF and ICP-AES data.

A Comprehensive Study of Three Different Portable XRF Scanners to Assess the Soil Geochemistry of An Extensive Sample Dataset

“…Despite these drawbacks, elemental analysis by XRF has proven to correlate well with commonly used laboratory methods such as atomic absorption spectrometry (AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), and inductively coupled plasma mass spectrometry (ICP-MS) [7,16,17]. Yet, soil datasets in these comparative studies were often limited to a few samples (<50) [11,18,19], a few elements (1)(2) [20][21][22][23][24], or to a restricted study area with similar land use or similar parent material [11,13,21,25,26]. Additionally, only a few studies have investigated the impact of different XRF scanners by comparing their mutual performances [27,28].…”

Mapping Heavy Metal Concentrations in Beach Sands Using GIS and Portable XRF Data

“…λ i corresponds to the weight of each data point for the unknown value, and N is the total amount of data used in the kriging prediction, i.e., the number of sampled datapoints. Kriging is divided into several methods based on the method used to determine the weight and ordinary kriging was used in this study, which is the most commonly used geostatistical estimator, and has been widely applied in the fields of soil pollution [21,22] and mineral resource exploration [23,24]. In this method, the equation is not biased when estimating unknown values and minimizes error variance.…”

Soil Contaminant Concentrations at Urban Agricultural Sites in New Orleans, Louisiana: A Comparison of Two Analytical Methods

“…Multiple companies that produce handheld XRF equipment explicitly state that lab-quality metal soil screening is an intended use (Bruker, n.d.; Olympus, n.d.; ThermoFisher Scientific, n.d.). XRF technology has been used widely and effectively in the mining industry, but its application in urban agriculture has been relatively limited (Suh, Lee, & Choi, 2016). However, according to Weindorf, Zhu, Chakraborty, Bakr, & Huang (2012) the XRF is capable of accurately quantifying some metals in soils sampled from a peri-urban agricultural setting.…”