Adsorption-desorption of parathion as affected by soil organic matter

For minimizing the transport of antibiotics to groundwater, the migration of antibiotics in soils should be investigated. Soil organic matter can affect the migration of antibiotics. To date, the influence of aromatics and aliphatic content of organic matter on the adsorption of antibiotics has been controversial. To better understand the reaction mechanism of soil organic matter with antibiotics, this study investigated the adsorption of oxytetracycline (OTC) by humus soils (HOS) and their fractions. HOS were sequentially fractionated into four organic fractions, including the removal of dissolved organic matter (HRDOM), removal of minerals (HRM), removal of free fat (HRLF), and nonhydrolyzable organic carbon (HNHC). Moreover, batch experiments revealed that adsorption capacity was ordered by HNHC > HOS > HRDOM > HRLF > HRM. SEM images and N2 adsorption/desorption isotherms indicate that adsorption capacity is independent of the external structure. However, adsorption capacity is related to the internal structure and composition. Combination analysis with elemental composition and infrared spectroscopy showed that the adsorption capacity of HRM, HRLF, and HNHC had a good positive correlation with aromaticity, but a negative correlation with polarity and hydrophilicity. Additionally, the rule of binding affinity between OTC and functional groups with different properties was summarized as aromatic > polarity > hydrophilic.

Download Full-text

Ionization and adsorption-desorption of tricyclazole by soil organic matter, montmorillonite clay and Cape Fear sandy loam soil

Journal of Agricultural and Food Chemistry ◽

10.1021/jf00111a042 ◽

1982 ◽

Vol 30 (3) ◽

pp. 584-588 ◽

Cited By ~ 14

Author(s):

Jerome B. Weber

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Sandy Loam ◽

Montmorillonite Clay ◽

Sandy Loam Soil ◽

Loam Soil ◽

Cape Fear ◽

Adsorption Desorption

Download Full-text

ADSORPTION AND DESORPTION OF UREA HERBICIDES ON SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss75-019 ◽

1975 ◽

Vol 55 (2) ◽

pp. 127-135 ◽

Cited By ~ 37

Author(s):

R. GROVER

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Matter Content ◽

Matter Content ◽

K Value ◽

Soil Organic Matter Content ◽

High Organic Matter Content ◽

High Organic Matter ◽

Adsorption Desorption ◽

Relative Adsorption

The adsorption/desorption potential of several phenylurea herbicides was studied on representative prairie soils, using slurry-type adsorption experiments. The herbicides showed the following order of increasing tendency to be adsorbed: fenuron < monuron [Formula: see text] monolinuron < metobromuron < diuron [Formula: see text] linuron [Formula: see text] chlorbromuron. The relative adsorption of each herbicide on various soil types was significantly correlated with the soil organic matter content, but not with the clay content. The relationship between the k value and the soil organic matter content was found to be of the exponential type. The extent of adsorption was also inversely related to the order of their water solubilities. The urea herbicides were readily desorbed by water from the low to medium organic matter content sandy loam and heavy clay soils, but not from a loam with very high organic matter content. It is suggested that the relative adsorption/desorption potential of a herbicide may provide a mechanism by which soil applied herbicides can be biologically inactivated more readily in soils of high organic matter content.

Download Full-text

Fluometuron Adsorption-Desorption Equilibria in Soil

Weed Science ◽

10.1017/s0043174500036675 ◽

1974 ◽

Vol 22 (2) ◽

pp. 106-110 ◽

Cited By ~ 36

Author(s):

K. E. Savage ◽

R. D. Wauchope

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Sandy Loam ◽

Equilibrium Constants ◽

Organic Matter Content ◽

Clay Content ◽

Matter Content ◽

Adsorbed State ◽

Significant Linear Correlation ◽

Adsorption Desorption

The adsorption-desorption equilibria of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] were studied; a slurry technique with soil at 0-bar moisture tension was used. The equilibria established with Bosket very fine sandy loam (VFSL) were evaluated by three equations. The equation best describing the adsorption isotherm was x/m = K1Ce+ K2Ce2. Successive equilibrations resulted in a shift in the equilibria toward the adsorbed state, most likeiy due to a physical change in the adsorption capacity of the soil with repeated agitation. Desorption studies with seven additional soils indicated the importance of soil organic matter content in the adsorption-desorption equilibria of fluometuron. The relationship between soil organic matter contents and the adsorption-desorption equilibrium constants was characterized by a highly significant linear correlation (r = 0.93) and the resulting regression equation: K1= 0.46 + 0.45(O.M.%). Clay content of these soils was not significantly correlated with fluometuron equilibrium constants.

Download Full-text