Evaluation of Reactive Mixtures for Removal of Arsenic From Groundwater

Angai, Joanne U.; Ptacek, Carol J.; Verbuyst, Brent; Bain, Jeff; Holland, Steven P.; Pakostová, Eva; White, Heather; Blowes, David W.

doi:10.1130/abs/2019am-337504

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The precipitation of these phases, notably realgar, occurs under reducing conditions and has been documented in tailings in direct contact with organic matter (Walker et al, 2009;DeSisto et al, 2016) and shallow aquifer sediments rich in organic matter (O'Day et al, 2004). The mechanisms of As sequestration by solid phases have been studied using multiple modalities including laboratory batch and column experiments (Bertocchi et al, 2006;Beesley & Marmiroli, 2011;Zhou et al, 2018;Du et al, 2019;Senthilkumar et al, 2020;Perez et al, 2021;Angai et al, 2022) as well as field-scale experiments and trials (Beak & Wilkin, 2009;He et al, 2010;Ludwig et al, 2009;Pi et al, 2017;Saunders et al, 2018;Lee et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Improved precision in As speciation analysis with HERFD-XANES at the As K-edge: the case of As speciation in mine waste

Saurette¹,

Frinfrock²,

Verbuyst³

et al. 2022

J Synchrotron Rad

Self Cite

View full text Add to dashboard Cite

High-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) is a spectroscopic method that allows for increased spectral feature resolution, and greater selectivity to decrease complex matrix effects compared with conventional XANES. XANES is an ideal tool for speciation of elements in solid-phase environmental samples. Accurate speciation of As in mine waste materials is important for understanding the mobility and toxicity of As in near-surface environments. In this study, linear combination fitting (LCF) was performed on synthetic spectra generated from mixtures of eight measured reference compounds for both HERFD-XANES and transmission-detected XANES to evaluate the improvement in quantitative speciation with HERFD-XANES spectra. The reference compounds arsenolite (As2O3), orpiment (As2S3), getchellite (AsSbS3), arsenopyrite (FeAsS), kaňkite (FeAsO4·3.5H2O), scorodite (FeAsO4·2H2O), sodium arsenate (Na3AsO4), and realgar (As4S4) were selected for their importance in mine waste systems. Statistical methods of principal component analysis and target transformation were employed to determine whether HERFD improves identification of the components in a dataset of mixtures of reference compounds. LCF was performed on HERFD- and total fluorescence yield (TFY)-XANES spectra collected from mine waste samples. Arsenopyrite, arsenolite, orpiment, and sodium arsenate were more accurately identified in the synthetic HERFD-XANES spectra compared with the transmission-XANES spectra. In mine waste samples containing arsenopyrite and either scorodite or kaňkite, LCF with HERFD-XANES measurements resulted in fits with smaller R-factors than concurrently collected TFY measurements. The improved accuracy of HERFD-XANES analysis may provide enhanced delineation of As phases controlling biogeochemical reactions in mine wastes, contaminated soils, and remediation systems.

show abstract