Laboratory study of retention and release of weak acid herbicide MCPA by soils and sediments and leaching potential of MCPA

MCPA sorption and desorption in five surface soils (denoted as A1-5), three bottom sediments (S1-3), two river sediments (L1-2) and one subsurface soil (SS) at two initial concentrations in aqueous solution – C0 = 0.5 and 10 mg/l were studied. No significant effect of the initial concentration on MCPA equilibrium distribution between soil/sediment and aqueous solution was observed. The difference between distribution coefficient KD at C0 = 0.5 mg/l and KD at C0 = 10 mg/l was found only in the case of one bottom sediment (S2). A simple regression analysis between KD at C0 = 0.5 and 10 mg/l and soil/sediment properties indicated that the most important property which determined the variation in MCPA sorption is organic carbon (r = 0.886*** and r = 0.926***, respectively). Similarly, desorption of MCPA was inversely proportional to organic carbon content of the soils and sediments used (r = –0.862* and r = –0.842**). These observations showed that MCPA sorption and desorption in soils and sediments were primarily controlled by organic components of the geosorbents used. Overall, the percentage of MCPA sorption in soils and sediments was low (Psorp ≈ 3–53%; KD = 0.077–2.827 l/kg) and the percentage of MCPA desorbed was relatively high (Pdes ≈ 11–70%), especially in the soils and sediments with lower organic carbon content. The experimental results and calculated values of groundwater ubiquity score GUS and relative leaching potential index RLPI imply that MCPA is very mobile in all the surface soils and has a potential to contaminate groundwater.

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Distribution of dioxins in surface soils and river-mouth sediments and their relevance to watershed properties

Water Science & Technology ◽

10.2166/wst.2006.034 ◽

2006 ◽

Vol 53 (2) ◽

pp. 11-21 ◽

Cited By ~ 9

Author(s):

M. Kanematsu ◽

Y. Shimizu ◽

K. Sato ◽

S. Kim ◽

T. Suzuki ◽

...

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

River Sediments ◽

River Mouth ◽

Organic Carbon Content ◽

Surface Soils ◽

The Difference ◽

To Come ◽

Ado River ◽

Calux Assay

The dioxins toxic equivalent (TEQ) concentration in surface soils, river sediments and river-mouth sediments was measured by the CALUX assay in the Yasu and Ado River basins around Lake Biwa, Japan. In order to examine the distribution of dioxins in each watershed, we evaluated and compared the correlation between the dioxins TEQ concentration and the solid characteristics (i.e. organic carbon content and particle size distribution) of all samples. In both basins, the dioxins TEQ concentration in forest soil correspondingly showed a very good linear relationship to organic carbon content. On the other hand, the dioxins TEQ concentration in paddy field was significantly high, although organic carbon content was relatively low. Generally, the smaller particles have the higher dioxins TEQ concentrations in surface soils, and river sediments were composed of very coarse particles and had relatively low dioxins TEQ concentration. Therefore, we expected high dioxins TEQ concentration in river-mouth sediment, which was, however, not the case. Although the dioxins TEQ concentration in river-mouth sediments is low, the degree of dioxins pollution was different in each basin. The difference was considered to come from the difference of watershed properties including land use, river-slope, dam construction as well as the surface soil pollution.

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Sorption of Metribuzin and Metolachlor in Alaskan Subarctic Agricultural Soils

Weed Science ◽

10.1017/s004317450005712x ◽

1992 ◽

Vol 40 (1) ◽

pp. 155-160 ◽

Cited By ~ 20

Author(s):

Jeff S. Graham ◽

Jeffery S. Conn

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

Soil Type ◽

Surface Soil ◽

Agricultural Soils ◽

Freundlich Isotherm ◽

Organic Carbon Content ◽

Surface Soils ◽

Adsorption And Desorption ◽

Equilibration Temperature

Adsorption and desorption of metribuzin and metolachlor were studied for 0- to 15- and 30- to 45-cm soil depths and at 5 and 28 C temperatures for two subarctic Alaskan agricultural soils. Surface soils had five to eight times the organic carbon content of deeper soils and had lower Freundlich isotherm slopes (1/n) for both herbicides. Surface soil Freundlich coefficients (Kf) were affected by both soil type and equilibration temperature, with soil type accounting for greater than 80% of the variation in Kf. Surface soil mean Kfvalues ranged from 1.5 to 2.4 for metribuzin and 4.4 to 9.2 for metolachlor. For soils from the 30- to 45-cm depth, neither soil type nor temperature affected Kf. Isotherm slopes for desorption were less than adsorption, indicating hysteresis. Regressions between desorption Kfand maximum herbicide adsorbed prior to desorption were highly significant with coefficients of determination (r2) between 0.50 and 0.99.

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Biofilm controlled sorption of selected acidic drugs on river sediments characterized by different organic carbon content

Chemosphere ◽

10.1016/j.chemosphere.2011.11.067 ◽

2012 ◽

Vol 87 (2) ◽

pp. 105-110 ◽

Cited By ~ 32

Author(s):

József Dobor ◽

Margit Varga ◽

Gyula Záray

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

River Sediments ◽

Organic Carbon Content ◽

Acidic Drugs

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Trace metal geochemistry in sediments from the Miramichi estuary, New Brunswick

Canadian Journal of Earth Sciences ◽

10.1139/e80-020 ◽

1980 ◽

Vol 17 (2) ◽

pp. 254-265 ◽

Cited By ~ 13

Author(s):

Joan D. Willey ◽

Robert A. Fitzgerald

Keyword(s):

Trace Elements ◽

Organic Matter ◽

Organic Carbon ◽

Carbon Content ◽

Size Fraction ◽

Fine Fraction ◽

Weak Acid ◽

Organic Carbon Content ◽

Sediment Fraction ◽

High Organic Carbon Content

Organic matter, mineralogy, and texturally-related qualities combine to control the total concentration and reactivity of trace metals in the sediments of the Miramichi estuary. Concentrations of lignin-rich organic matter, up to 10% of the total sediment weight in the central estuary, correlate with analytical results for trace elements which show that more than 40% of the total Mn, Zn, and Cu is held in the oxidizable and organically-bound form. Mineralogical influences are most obvious in the river portion of the system where total Mn concentrations average 695 μg/g, Zn averages 282 μg/g, Cu averages 32 μg/g, and Pb averages 200 μg/g in the less than 63 μm size fraction of the sediments. In the marginal marine Miramichi Bay, total concentrations of these four trace elements in the fine sediment fraction are diminished by 9–57%, with respect to the equivalent size fraction of the river sediments.The concentration of all trace elements in the coarse fraction (> 63 μm) is considerably less as compared with the fine fraction. In these sediments mineralogical associations are more pro nounced. Very high organic carbon content (up to 23%) is associated with sediments in which more than 25% of the Mn, Zn, and Cu is organically bound. Weak acid leachable Ca in the coarse sediments of the bay is 21 times higher as compared with the equivalent river sediment fraction and this CaCO3 indication is associated with a twofold increase in total Cu and Pb.When compared with sediments from other areas of eastern Canada, the Miramichi sediments have at least twice as much weak acid leachable Zn, and this higher level of reactive metal is associated with high organic carbon content in the top 15 cm of cored sediments. Suggested sources for this recent addition of metal in association with organic matter are the mining activities as well as urban and industrial effluents.

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Adsorption of Clomazone on Soils, Sediments, and Clays

Weed Science ◽

10.1017/s0043174500072192 ◽

1989 ◽

Vol 37 (3) ◽

pp. 440-444 ◽

Cited By ~ 26

Author(s):

Mark M. Loux ◽

Rex A. Liebl ◽

Fred W. Slife

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

Water Solubility ◽

Clay Content ◽

Organic Coatings ◽

Organic Carbon Content ◽

Adsorption Sites ◽

Water Partition Coefficient ◽

Soils And Sediments ◽

Hydrophobic Bonding

Regression analysis of clomazone adsorption on 19 soils and sediments yielded a positive correlation and linear relationship between distribution adsorption constants (Kd) and soil organic carbon content. The agreement of the experimental mean Kocwith Kocvalues predicted from the octanol-water partition coefficient and water solubility of clomazone indicated hydrophobic bonding was one mechanism responsible for adsorption. Kaolinite and montmorillonite had a strong affinity for clomazone, and adsorption increased with the charge of the cation on the clay exchange sites. Adsorption was not correlated with the clay content of soils and sediments, indicating that organic coatings on clay in soils may block adsorption sites on clay surfaces. The adsorption of clomazone on some soils and sediments with high clay contents was greater than predicted based on organic carbon content alone, however, indicating clay contributed to adsorption on these samples.

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