Magnetite interaction with arsenic during sorptive removal from groundwater: a mechanistic study.

A magnetic mixed iron oxide, magnetite (FeO), was synthesized in the laboratory and characterized before its use as sorbent for arsenic removal. The characterization techniques used were X-ray diffraction (XRD), specific surface area, zeta potential and particle size measurements. The sorbent was applied for arsenic removal, without any pre or post treatment, from groundwater.

Evidences on As(III) and As(V) interaction with iron(III) oxides: Hematite and goethite.

Arsenic, which is ubiquitous in nature, was found associated with iron oxides in soils and sediments. Our interest was to utilize the same mechanism for the sorptive removal of arsenic from groundwater. The iron(III) oxides: hematite, goethite, were synthesized, characterized and sorption studies of arsenic [As(III) and As(V)] were carried out in batch mode.

Study on the performance and interaction of different synthetic iron oxides for arsenic uptake using As radiotracer.

A radiotracer technique was employed to study the sorption of As(III) and As(V) on chemically synthesized iron oxides: magnetite (FeO), goethite (α-FeOOH) and hematite (FeO) by batch equilibration mode. Magnetite and goethite were found to be promising sorbents for arsenic removal and applied to real ground water from West Bengal, India. A solvent extraction method using benzene was applied for the investigation of oxidation state of sorbed arsenic.

Interaction of arsenic(III) and arsenic(V) on manganese dioxide: XPS and electrochemical investigations.

Manganese dioxide (MnO) synthesized by solid-state reaction was characterized and sorption of As(III) and As(V) on it was studied in batch mode using As radiotracer. Arsenic removal efficiency was ∼98 % in the pH range of 3-9. Solvent extraction study indicated that >95% of arsenic is present as As(V) after sorption.

Sorption of arsenic on manganese dioxide synthesized by solid state reaction.

Arsenic in groundwater is a major concern in many parts of the world and suitable sorbents are required for removal of arsenic from ground water. Removal of arsenic from groundwater has been studied using manganese dioxide, synthesized by solid state reaction of manganese acetate with potassium permanganate. Manganese dioxide was characterized by X-ray diffraction (XRD), zeta potential, surface area, particle size measurements and thermal analysis.

Sorption of As(III) and As(V) on chemically synthesized manganese dioxide.

Sorption of As(III) and As(V) on manganese dioxide was studied by batch equilibration method using (76)As radioactive tracer. Manganese dioxide was prepared by two different methods viz. reacting (a) KMnO(4) solution with MnSO(4) solution, and (b) KMnO(4) solution with concentrated hydrochloric acid.