The phosphate desorption rate in soil limits phosphorus bioavailability to crops

Desorption rate curves of n-pentane on 5A zeolites at 418 K and 10-0.03 kPa were determined, and the effects of different macropore structure on desorption performance were analyzed. Results show that macropore distribution of 5A-1 concentrates in 0.25-1.25 μm, while that of 5A-2 ranges from mesopore category to 0.3 μm, but 5A-3 contains both pores of 0.01-0.1 μm and 0.2-2 μm inside, reflecting a broadest distribution; 5A-3, 5A-1 and 5A-2 reach desorption equilibrium after 1100 s, 1400 s and 2000 s respectively at 0.03 kPa, indicating that abundant macropores make n-pentane fastest desorbed from 5A-3, but this advantage gradually disappears with the increasing pressure; the effective desorption diffusion coefficients of n-pentane on 5A-1, 5A-2 and 5A-3 are 4.2×10-15-2.2×10-14 m2/s, 2.0×10-15-2.3×10-14 m2/s, 7.4×10-15-2.4×10-14 m2/s respectively, suggesting that plenty macropores make the diffusivity less affected by the changes of pressure, which can guarantee a fast diffusion rate of n-pentane even at low pressure.

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Electron stimulated desorption of vanadyl-groups from vanadium oxide thin films on Ru(0001) probed with STM

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06419j ◽

2021 ◽

Vol 23 (14) ◽

pp. 8439-8445

Author(s):

Ying Wang ◽

Piotr Igor Wemhoff ◽

Mikołaj Lewandowski ◽

Niklas Nilius

Keyword(s):

Thin Films ◽

Vanadium Oxide ◽

Electron Injection ◽

Underlying Mechanism ◽

Desorption Rate ◽

Oxide Thin Films ◽

Current Dependence ◽

Electron Stimulated Desorption ◽

Vanadium Oxide Thin Films

Electron injection from an STM tip has been used to desorb individual vanadyl groups from vanadium oxide thin films. The underlying mechanism is analyzed from the bias and current dependence of the desorption rate.

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Factors Influencing Desorption of Mercury from Bed Sediments

Canadian Journal of Earth Sciences ◽

10.1139/e75-094 ◽

1975 ◽

Vol 12 (6) ◽

pp. 1036-1040 ◽

Cited By ~ 17

Author(s):

Akira Kudo ◽

D. C. Mortimer ◽

J. Sanford Hart

Keyword(s):

Environmental Conditions ◽

Total Mercury ◽

Exposure Period ◽

Desorption Rate ◽

Overlying Water ◽

Bed Sediments ◽

Ottawa River ◽

Factors Influencing ◽

River Bed

The desorption rate of mercury from bed sediments was determined by a 10 week experiment. The rates ranged from 0.1 ng/cm2/day to 1.0 ng/cm2/day for Ottawa River bed sediments, depending on the environmental conditions. The rates decreased with an increase of exposure period to the water, but increased with an increase in the depth of bed sediments. The amount of mercury desorbed from bed sediments to overlying water was highly dependent on the volume (depth) of bed sediments. Calculations based on the experiment showed the half-lives of total mercury associated with bed sediments from as short as 2.1 years to as long as 1.8 × 102 years, depending on the depth of the bed sediments.

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