Bismuth(III) Forms Exceptionally Strong Complexes with Natural Organic Matter

Abstract

The use of bismuth in the society has steadily increased during the last decades, both as a substitute for lead in hunting ammunition and various metallurgical applications, as well as in a range of consumer products. At the same time, the environmental behavior of bismuth is largely unknown. Here, the binding of bismuth­(III) to organic soil material was investigated using extended X-ray absorption spectroscopy (EXAFS) and batch experiments. Moreover, the capacity of suwannee river fulvic acid (SRFA) to enhance the solubility of metallic bismuth was studied in a long-term (2 years) equilibration experiment. Bismuth­(III) formed exceptionally strong complexes with the organic soil material, where >99% of the added bismuth­(III) was bound by the solid phase, even at pH 1.2. EXAFS data suggest that bismuth­(III) was bound to soil organic matter as a dimeric Bi3+ complex where one carboxylate bridges two Bi3+ ions, resulting in a unique structural stability. The strong binding to natural organic matter was verified for SRFA, dissolving 16.5 mmol Bi per gram carbon, which largely exceeds the carboxylic acid group density of this compound. Our study shows that bismuth­(III) will most likely be associated with natural organic matter in soils, sediments, and waters.

The Source, Mobility and Fate of Bismuth (Bi) in Legacy Mine Waste, Yxsjöberg, Sweden

“…With that in mind, these data indicate that low concentrations of Bi were kept in the dissolved phase (<0.22 µm) due to complexation with DOC in the groundwater. The significant relationship observed between Bi and DOC in the groundwater agrees with the findings of [44], indicating that Bi forms very strong complexes with natural organic matter.…”

“…According to the sequential extraction from P4, higher concentrations of Bi were released from exchangeable phases throughout the tailings, indicating that either (1) 30%-40% of all Bi had been released from bismuthinite in the tailings and adsorbed as exchangeable fractions, or (2) bismuthinite is easily weathered in low-pH environments with high organic matter, which was the geochemical environment at the leaching step. A newly published paper by [44] showed that Bi forms exceptionally strong complexes with natural organic matter and with a wide range of organic acids. This supports alternative two, meaning that the acetic acid with a pH of 4 added in Step 2 likely affected the results of the sequential extraction.…”

Photocatalytic Degradation of Tetracycline Hydrochloride Based on the Structure–Property Exploration of BiOCl

“…SEM and TEM show that BOC-3 consisted of microplates with a width of 1–3 μm and thickness of ∼200 nm (Figure a–f). It was proposed that Bi­(NO 3 ) 3 initially reacted with H 2 O to form [Bi 6 O 4 (OH) 4 (NO 3 ) 5 (H 2 O)]­(NO 3 ) and [Bi 6 O 4 (OH) 4 (NO 3 ) 6 (H 2 O) 2 ]·H 2 O precipitates, which then converted to BiOCl crystals during the hydrothermal treatment in the presence of Cl – at 160 °C . In contrast, BOC-1 and BOC-2 prepared in EG exhibited broad and weak XRD patterns (Figure g), indicating small size or poor crystallinity.…”

“…precipitates, which then converted to BiOCl crystals during the hydrothermal treatment in the presence of Cl − at 160 °C. 30 In contrast, BOC-1 and BOC-2 prepared in EG exhibited broad and weak XRD patterns (Figure 1g), indicating small size or poor crystallinity. As Bi(NO 3 ) 3 and NaCl could be completely dissolved in EG, the BiOCl nuclei formed and grew gradually at elevated temperatures, resulting in nanosheets with a diameter of ∼100 nm.…”

Soil Profile Concentration Distributions of Antimony and Bismuth across Southeastern Missouri (USA)

“…Solution pH and the presence of citric acid, tartaric acid, L-cysteine, and soil humic acids influenced bismuth solubility. Kleja et al [18] investigated the binding of Bi3+ to organic soil materials and noted that Bi3+ formed organic soil complexes, forming a dimeric Bi3+ complex.…”