Agricultural leachates

The pathway for the degradation of metribuzin that has been used as a herbicide has been established, and attention has been directed to the occurrence of the metabolites in leachate from agricultural soil in Denmark. Although the parent metribuzin was not found, the metabolites produced by loss of the N-amino group and the thiomethyl groups were produced and contributed to ground-water contamination (Kjaer et al. 2005). 

In silt clay soils (0-30 cm) of Isfahan, Central Iran, the amount of EDTA-extractable Zn, Cu, Pb, Ni, Cd, Co and Cr were 3.2, 1.8, 2.6, 0.6, 0.16, 0.6 and 0.8 mg/kg, respectively (Khoshgoftarmanesh and Kalbasi, 2002). Concentrations of these trace elements increased in subsoils (30-60 cm) and increased with applications of municipal waste leachate. In the surface soils of agricultural, industrial and urban regions of Isfahan, central Iran, the average DTPA-Cd was 0.09 mg/kg, and about 80% of the soil samples had less than 0.1 mg/kg DTPA-extractable Cd (Amini et al., 2005). DTPA-Cd was strongly correlated with EC in the soils. 

Precipitation inhibitors, dispersants contrasted, 3 686 Precipitation leachate procedure, synthetic, 25 868-869 Precipitation reactions, for niobium and tantalum determination, 27 142-143 Precipitation reagents, protein, 22 133 Precipitation with compressed antisolvent (PCA) process, 24 17, 18 Precipitator dust, in phosphorus manufacture, 19 12 Precipitators, electrostatic, 23 180 Precision agriculture, 23 328 26 269-270 Precision measurement techniques, noble gases in, 27 370 Precision scales, 26 245 Preconcentration, of uranium ores, 25 401 Pre-crosslinked polychloroprene grades, 19 852... 

Possible releases of heptachlor to soil may occur at hazardous waste sites or as a result of landfill leachate. Residues of heptachlor or heptachlor epoxide exist in soil as a result of past usage of heptachlor for both agricultural and nonagricultural purposes. Heptachlor was detected in 0.71% of the soil samples taken from the NPL sites included in the CLPSD at an estimated mean concentration of 4.07 ppb in the positive samples (CLPSD 1989). Heptachlor epoxide was not listed in the CLPSD of chemicals detected in soil samples collected at NPL sites. Note that the information from the CLPSD includes data from NPL sites only. 

Groundwater contamination in the U.S. was reviewed by Pye et al. in 1983 (J. The most common sources of such contamination included human and animal wastes, industrial wastes, petroleum products, landfill leachate, and (along coastal regions) saltwater intrusion. Contamination from the agricultural use of pesticides was apparently far less common. Nevertheless, by 1984, Cohen et al. (2) reported that... 

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