Department of Civil and Environmental Engineering, Carnegie Mellon University, United States.
Chevron Energy Technology Company, United States.
Environ Pollut. 2023 Jan 1;316(Pt 2):120558. doi: 10.1016/j.envpol.2022.120558. Epub 2022 Oct 31.
Soil salinization resulting from anthropogenic activities affects soil health and productivity. Methods that can provide rapid, inexpensive, and accurate salinity characterization over vast areas of soil and waste materials will help in managing their impacts. The objective of this work was to evaluate the accuracy and precision of portable X-ray Fluorescence (pXRF) Cl measurements of highly saline waste material (WMs) from oil and gas production sites. We compared pXRF Cl measurements of three unconsolidated WMs to a standard laboratory method for determining soil salinity and identified the WM properties that most affect the precision and accuracy of the pXRF Cl measurement. Despite covering a range of several orders of magnitude in chloride concentration, calibrated pXRF measurements varied by no more than 14% compared to standard laboratory Cl measurements for dry homogenous samples. Measurements taken of WMs that were not homogenized decreased pXRF accuracy by 75% while moisture content decreased accuracy by 15%. Field measurements made at different areas inside an oil and gas WM pit were accurate within 60% of the standard laboratory Cl measurements, despite the samples having a wide range of moisture content and particle size distributions. This study indicates that pXRF can be used to rapidly characterize soil salinity in-situ with acceptable accuracy and precision for screening purposes, opening the door for automated robotic measurements of chloride over large areas.
人为活动导致的土壤盐渍化影响土壤健康和生产力。能够快速、廉价、准确地描述大面积土壤和废物盐分特征的方法，将有助于管理其影响。本工作的目的是评估便携式 X 射线荧光（pXRF）测定高度盐渍废物（WM）中氯的准确性和精密度，这些 WM 来自油气生产场地。我们将三种未固结 WM 的 pXRF 氯测量值与标准实验室测定土壤盐度的方法进行了比较，并确定了对 pXRF 氯测量值的精度和准确性影响最大的 WM 特性。尽管氯化物浓度范围跨越了几个数量级，但对于干燥均匀的样品，校准后的 pXRF 测量值与标准实验室 Cl 测量值的偏差不超过 14%。对于未均匀化的 WM 进行的测量降低了 pXRF 的准确性达 75%，而含水量降低了 15%。在油气 WM 坑内不同区域进行的现场测量，其准确性在标准实验室 Cl 测量值的 60%以内，尽管样品的含水量和粒径分布范围很广。这项研究表明，pXRF 可用于原位快速测定土壤盐分，具有可接受的准确性和精密度，可用于筛选目的，为大面积自动机器人测量氯化物开辟了道路。
