Arsenite oxidation by a poorly-crystalline manganese oxide. 3. Arsenic and manganese desorption.

Arsenite oxidation by a poorly crystalline manganese-oxide. 2. Results from X-ray absorption spectroscopy and X-ray diffraction.

Arsenite (As(III)) oxidation by manganese oxides (Mn-oxides) serves to detoxify and, under many conditions, immobilize arsenic (As) by forming arsenate (As(V)). As(III) oxidation by Mn(IV)-oxides can be quite complex, involving many simultaneous forward reactions and subsequent back reactions. During As(III) oxidation by Mn-oxides, a reduction in oxidation rate is often observed, which is attri...

The influence of environmental conditions on kinetics of arsenite oxidation by manganese-oxides

BACKGROUND Manganese-oxides are one of the most important minerals in soil due to their widespread distribution and high reactivity. Despite their invaluable role in cycling many redox sensitive elements, numerous unknowns remain about the reactivity of different manganese-oxide minerals under varying conditions in natural systems. By altering temperature, pH, and concentration of arsenite we w...

The Effects of Iron(ii) on Arsenic(iii) Oxidation and Arsenic Sorption/desorption on Manganese Oxides

Arsenic(III) oxidation and arsenic(V) adsorption reactions on synthetic birnessite.

The oxidation of arsenite (As(III)) by manganese oxide is an important reaction in both the natural cycling of As and the development of remediation technology for lowering the concentration of dissolved As(III) in drinking water. This study used both a conventional stirred reaction apparatus and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the reactions of As(II...

Simultaneous treatment of both As(III) and As(V) with Iron-Coated Sand (ICS) and Manganese-Coated Sand (MCS)

From the natural geochemical process and anthropogenic activities such as mining wastes, petroleum refining, and agricultural chemicals, surface and groundwater are widely contaminated with arsenic (Bhumbla and Keefer, 1994). Inorganic arsenic is commonly present as arsenite and arsenate depending on the aquatic redox systems. In anoxic systems such as groundwater, the stable form of arsenic is...