Arsenic sorbs strongly to the surfaces of Fe(III) (hydr)oxides. Under aerobic conditions, oxygen acts as the terminal electron acceptor in microbial respiration and Fe(III) (hydr)oxides are highly insoluble, thus arsenic remains associated with Fe(III) (hydr)oxide phases. However, under anaerobic conditions Fe(III)-reducing microorganisms can couple the reduction of solid phase Fe(III) (hydr)ox...

We studied the effects of humic substances (HS) on the sorption of Fe(II) onto Al-oxide and clay sorbents at pH 7.5 with a combination of batch kinetic experiments and synchrotron Fe K-edge EXAFS analyses. Fe(II) sorption was monitored over the course of 4 months in anoxic clay and Al-oxide suspensions amended with variable HS types (humic acid, HA; or fulvic acid, FA) and levels (0, 1, and 4 w...

The term "Carlin-type" deposit has been applied to a number of low-grade, sedimentary rock-hosted gold deposits that have been discovered and brought into production in the western United States since the 1960s. Carlin-type deposits are characterized by replacement of carbonate and silty carbonate rocks by silica, pyrite, barite, various arsenic, mercury, antimony, and thallium minerals and by ...

The objective of this research is to determine all processes in the magmatic evolution and related hydrothermal activities that created the volcanic rocks and associated ore-forming systems of the Bafq ‎mining district. Several iron oxide-apatite (IOA) deposits were investigated in this area with a focus on the Sechahun ore deposit. The Bafq ‎mining district is well known for hosting significan...

[1] Phyllosilicates have previously been detected in layered outcrops in and around the Martian outflow channel Mawrth Vallis. CRISM spectra of these outcrops exhibit features diagnostic of kaolinite, montmorillonite, and Fe/Mg-rich smectites, along with crystalline ferric oxide minerals such as hematite. These minerals occur in distinct stratigraphic horizons, implying changing environmental c...

In this paper, a remote O2 ion source is used for the formation of nano-oxide layers. The oxidation efficiency was measured in CoFe-oxide films, and a decrease of the oxide layer with the pan angle and the oxidation pressure is observed. For the same oxidation pressure, the oxidation efficiency depends on the O2 content in the Ar–O2 plasma. These results were applied in optimizing the fabricati...

This study describes a method used to improve ore grade estimation in a limestone deposit in India. Ore grade estimation for the limestone deposit was complicated by the complex lithological structure of the deposit. The erratic nature of the deposit and the unavailability of adequate samples for each of the lithogical units made standard geostatistical methods of capturing the spatial variatio...

nano-encapsulated iron oxide in zirconium oxide-coated mica pigments are thermally stable,innocuous to human health, non-combustible, and they do not conduct electricity. they could beapplied in several industries such as thermoplastics, cosmetics, food packaging, children toys, paints,automobiles coating, security purposes, and banknotes. nowadays, they are highly desirable inceramic decoratio...

The unique active site of flavo-diiron proteins (FDPs) consists of a nonheme diiron-carboxylate site proximal to a flavin mononucleotide (FMN) cofactor. FDPs serve as the terminal components for reductive scavenging of dioxygen or nitric oxide to combat oxidative or nitrosative stress in bacteria, archaea, and some protozoan parasites. Nitric oxide is reduced to nitrous oxide by the four-electr...