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Experimental and Predicted Movement of Three Herbicides in a Water‐Saturated Soil
Author(s) -
Davidson J. M.,
McDougal J. R.
Publication year - 1973
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1973.00472425000200040003x
Subject(s) - loam , effluent , adsorption , desorption , chemistry , freundlich equation , pore water pressure , soil water , environmental chemistry , soil science , environmental engineering , environmental science , geology , geotechnical engineering , organic chemistry
The equilibrium adsorption characteristics of 1,1‐dimethyl‐3‐(a,a,a‐trifluoro‐ m ‐tolyl) urea (fluometuron), 4‐amino‐3,5,6‐trichloropicolinic acid (picloram), and 2,4‐bis(isopropylamino)‐6‐(methylthio)‐s‐triazine (prometryne) on Ca‐saturated Norge loam soil were measured and were found to fit the Freundlich equation. A solution of each herbicide was displaced through a water‐saturated colume of Norge loam soil at various average pore‐water velocities (5.6 to 0.57 cm/hour) and effluent samples evaluated to determine the importance of adsorption kinetics to the mobility of the herbicide. The displacement of each herbicide through the soil was significantly influenced by the average pore‐water velocity. The use of a kinetic adsorption model in a convective transport equation did not adequately predict the shape of the effluent concentration distribution at the high pore‐water velocities, but did give the left‐hand shift exhibited by the data. The tailing noted in all the herbicide effluent concentration distributions resulted primarily from the nonsingularity between the adsorption‐desorption process. Equilibrium adsorption and desorption isotherms were measured for picloram on Ca‐saturated Norge loam soil.