Molybdenum Adsorption on Oxides, Clay Minerals, and Soils

Goldberg, Sabine; Förster, Helga; Godfrey, Curtis L.

doi:10.2136/sssaj1996.03615995006000020013x

Cited by 277 publications

(142 citation statements)

References 42 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…This pH control also explains the behaviour observed for Soil H2, where greater pH buffering leads to lower overall experimental pH and lower aqueous Al, As and V concentrations in those tests. Mo, however, only weakly interacts with soil minerals at circumneutral pH (Buekers et al 2010;S Goldberg and Forster 1998;S. Goldberg et al 1996), and therefore, remains highly soluble at the pH values observed in experiments where gypsum was present.…”

Section: Effectiveness Of Gypsum For the Treatment Of Red Mud Contamimentioning

confidence: 94%

Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility

Lehoux

Lockwood

Mayes

et al. 2013

Environ Geochem Health

View full text Add to dashboard Cite

Red mud is highly alkaline (pH 13), saline and can contain elevated concentrations of several potentially toxic elements (e. proportional to red mud addition, of up to 4 pH units (e.g. pH 7  11). Increasing red mud addition also led to significant increases in salinity, dissolved organic carbon (DOC) and aqueous trace element concentrations. However, the response was highly soil specific and one of the soils tested buffered pH to around pH 8.5 even with the highest red mud loading tested (33% w/w); experiments using this soil also had much lower aqueous Al, As, and V concentrations. Gypsum addition to soil / red mud mixtures, even at relatively low concentrations (1% w/w) was sufficient to buffer experimental pH to 7.5-8.5. This effect was attributed to the reaction of Ca 2+ supplied by the gypsum with OH -and carbonate from the red mud to precipitate calcite. The lowered pH enhanced trace element sorption and largely inhibited the release of Al, As and V. Mo concentrations, however, were largely unaffected by gypsum induced pH buffering due to the greater solubility of Mo (as molybdate) at circumneutral pH. Gypsum addition also leads to significantly higher porewater salinities and column experiments demonstrated that this increase in total dissolved solids persisted even after 25 pore volume replacements. Gypsum addition could therefore provide a cheaper alternative to recovery (dig and dump) for treatment of red mud affected soils. The observed inhibition of trace metal release within red mud affected soils was relatively insensitive to either the percentage of red mud or gypsum present, making the treatment easy to apply. However, there is risk that over-application of gypsum could lead to detrimental long term increases in soil salinity.g

show abstract

Section: Effectiveness Of Gypsum For the Treatment Of Red Mud Contamimentioning

confidence: 94%

Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility

Lehoux

Lockwood

Mayes

et al. 2013

Environ Geochem Health

View full text Add to dashboard Cite

show abstract

“…There are as of yet no data on the isotopic composition of clay minerals, and thus a quantitative estimate of their influence on the isotopic composition is not possible. However, in their experimental study on Mo adsorption to a variety of clays and hematite Goldberg et al (1996) demonstrated that adsorption to hematite is much stronger and occurs over a broader pH-range. Most notably, above a pH of 7 adsorption to clays is virtually zero whereas comparably strong adsorption still occurs to hematite.…”

Section: /95mentioning

confidence: 99%

Molybdenum isotopic composition of modern and Carboniferous carbonates

et al. 2009

View full text Add to dashboard Cite

We investigate the redox-sensitive isotope system of molybdenum (Mo) in marine carbonates to evaluate their potential as archive of the Mo isotopic composition of coeval seawater. We present Mo isotope data (δ 98/95 Mo) of modern skeletal and non-skeletal carbonates as well as a variety of precipitates from the mid and late Carboniferous. The external reproducibility is determined by repeated analyses of two commercially available carbonate standards. The resulting uncertainty of the low concentration samples is ±0.1‰ (2σ). Analysis of modern ooid sands from the Bahamas shows a consistently heavy Mo isotopic composition (δ 98/95 Mo between 2 and 2.2‰), approaching modern mean seawater values (δ 98/95 Mo = 2.3‰ ± 0.1‰ (2σ)). This suggests that isotope fractionation during Mo uptake into non-skeletal carbonate precipitates is small. In contrast, modern skeletal carbonates show variable isotopic compositions (0.1 to 2.2‰) which suggests a biologically controlled fractionation process. The varying Mo signatures found in Carboniferous cement phases point to a strong response to local changes in fluid composition from which they precipitated. Overall, we recognized three important factors to cause an offset relative to ocean water: Mo derived from skeletal components, input of detrital Mo and admixture of light, hydroxide derived Mo via diagenetic fluids. All of these factors cause a lighter Mo isotopic composition relative to seawater. Due to the apparent small isotope fractionation during Mo uptake into non-skeletal carbonates, their δ 98/95Mo closely reflects the ambient fluid composition. From these results we conclude that carbonates represent a promising new tool to characterize the water mass Mo isotopic composition of marine paleo-environments.

show abstract

“…With implementation of the wetland, its concentration in water increased up to 3 mg/L after one year of remediation, probably due to release from secondary minerals ( Figure 6F). The adsorption of Mo on Fe oxide decreased with increasing pH and the implementation of the wetland favored the Mo desorption [33]. Then Mo concentration in solution decreased below the detection limit as a consequence of secondary sulfides precipitation as suggested by sequential extraction data ( Figure 7G).…”

Section: Geochemical Evolution In the DC Tailings Stratigraphy Over Timementioning

confidence: 85%

Evolution of Geochemical and Mineralogical Parameters during In Situ Remediation of a Marine Shore Tailings Deposit by the Implementation of a Wetland Cover

Diaby

Dold

2014

Minerals

View full text Add to dashboard Cite

We present data of the time-evolution of a remediation approach on a marine shore tailings deposit by the implementation of an artificial wetland. Two remediation cells were constructed: one in the northern area at sea-level and one in the central delta area (above sea-level) of the tailings. At the beginning, the "sea-level" remediation cell had a low pH (3.1), with high concentrations of dissolved metals and sulfate and chloride ions and showed sandy grain size. After wetland implementation, the "sea-level" remediation cell was rapidly water-saturated, the acidity was consumed, and after four months the efficiency of metal removal from solution was up to 79.5%-99.4% for Fe, 94.6%-99.9% for Mn, and 96.1%-99.6% for Zn. Al and Cu concentrations decreased below detection limit. The "above sea-level" remediation cell was characterized by the same pH (3.1) and finer grain size (clayey-silty), and with some lower element concentrations than in the "sea-level" cell. Even after one year of flooding, the "above sea-level" cell was not completely flooded, showing on-going sulfide oxidation in between the wetland cover and the groundwater level; the pH increased only to 4.4 and metal concentrations decreased only by 96% for Fe, 88% for Al, 51% for Cu, 97% for Mn, and 95% for Zn. During a dry period, the water level dropped in the "sea-level" cell, resulting in a seawater ingression, which triggered the desorption of As into solution. These data show that the applied OPEN ACCESSMinerals 2014, 4 579 remediation approach for this tailings deposit is successful, if the system is maintained water-saturated. Metal removal from solution was possible in both systems: first, as a result of sorption on Fe(III) hydroxide/and/or clay minerals and/or co-precipitation processes after rise of pH; and then, with more reducing conditions, due to metal sulfides precipitation.

show abstract

Molybdenum Adsorption on Oxides, Clay Minerals, and Soils

Cited by 277 publications

References 42 publications

Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility

Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility

Molybdenum isotopic composition of modern and Carboniferous carbonates

Evolution of Geochemical and Mineralogical Parameters during In Situ Remediation of a Marine Shore Tailings Deposit by the Implementation of a Wetland Cover

Contact Info

Product

Resources

About