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2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

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Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology<br />

cance increased after excluding the soil A8 from the data set<br />

(r = 0.766; P < 0.01).<br />

The method of step-down multiple regression analysis<br />

was used to determine the soil properties significantly<br />

contributing to the overall acetochlor sorption. The soil A8<br />

appeared to have specific sorption properties, thus it wasn’t<br />

included in the analysis. The analysis yielded the following<br />

equations:<br />

K d = 1.043(TOC %) + 1.725(C HA /C FA )–0.777 (1)<br />

R 2 = 0.888; n = 12; P < 0.001; SE = 0.67<br />

K d = 0.891(TOC %) + 1.723(C HA /C FA )–1.011 (2)<br />

R 2 = 0.914; n = 12; P < 0.001; SE = 0.497<br />

The equations (1) and (2) were acquired when the<br />

results obtained at initial acetochlor concentrations of 1 and<br />

10 mg dm –3 were used, respectively. The K d of acetochlor<br />

was found to depend significantly on the total organic carbon<br />

content of the soil/sediment. The distribution of humus components<br />

expressed as the C HA /C FA ratio is also a significant<br />

factor influencing the acetochlor affinity to the sorbents.<br />

Desorption of acetochlor from all soils and sediments<br />

was less than the amount initially sorbed (Table II). Desorption<br />

extent is significantly (r = –0.81; P < 0.01) influenced by<br />

total organic carbon content, with greater organic carbon contents<br />

reducing the desorption. Significant inverse correlations<br />

were also found between the humic components (C HA and<br />

s528<br />

C FA ) and P des , but no other significant correlations between<br />

P des and soil/sediment properties were observed.<br />

Conclusions<br />

Organic matter appears to be the main sorbent constituent<br />

responsible for acetochlor retention in soils/sediments,<br />

with both quantitative and qualitative parameters playing<br />

important role in its ability to bind acetochlor. The specific<br />

appearance of the clay-rich soil A8 in whole analysis implies<br />

that mineral surfaces can also significantly contribute to acetochlor<br />

immobilization under favourable conditions.<br />

This work has been supported by VEGA projects No.<br />

1/4036/07 and No 1/4047/07. We would like to acknowledge<br />

the Water Research Institute Bratislava.<br />

REFEREnCES<br />

1. Tomlin C. D. S.: The e-pesticide manual, 12 th ed. CD-<br />

ROM form, Version <strong>2.</strong>0. British Crop Protection Council<br />

2001.<br />

<strong>2.</strong> Ye C.: Bull. Environ. Contam. Toxicol. 71, 919 (2003).<br />

3. Ferri M. V. W., Gomes J., Dick D. P., de Souza R. F.,<br />

Vidal R. A.: Rev. Bras. Ci. Solo 29, 705 (2005).<br />

4. Sheng G., Johnston C. T., Teppen B. J., Boyd S. A.: J.<br />

Agric. Food Chem. 49, 2899 (2001).<br />

5. Dousset S., Mouvet C., Schiavon M.: Chemosphere 28,<br />

467 (1994).

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