Facilitated transport of pesticides
Detachment
(MACRO-formulation, Jarvis)
DET = kd·KET·Ms·
Pesticide-Soil
Cpest=Solubilitypest
Pest.-
dissolved
Kds
Kdc
RAIN
Amount of
pesticide
Amount of
colloids/particles
Colloid conc.
TRANSPORT
FIGURE 4.8.SKETCH OF HOW CONCENTRATIONS ARE ASSIGNED IN THE OVERLAND COMPARTMENT.
RAINFALL DETACHES AN AMOUNT OF PARTICLES, WHICH ARE PUT INTO THE OVERLAND COMPARTMENT.
THE PESTICIDE ON THE SOIL SURFACE IS TRANSFERRED TO THE RAINWATER AT A CONCENTRATION EQUAL TO
THE SOLUBILITY AS LONG AS THERE IS PESTICIDE ENOUGH PRESENT TO MAINTAIN THIS CONCENTRATION. IN
THE OVERLAND COMPARTMENT THE PESTICIDE IS DISTRIBUTED BETWEEN THE THREE POSSIBLE STATES. HENCE,
THE OBTAINABLE CONCENTRATION OF MOBILE PESTICIDE IS LIMITED BY THE SOLUBILITY OF THE PESTICIDE.
FIGURE 4.8.SKITSE AF HVORLEDES PESTICIDET FORDELES I ”OVERLAND COMPARTMENT” I MODELLEN.
REGNEN FRIGØR EN VIS MÆNGDE PARTIKLER SOM TILFØRES OVERLAND COMPARTMENT. PESTICIDET AFSAT
PÅ OVERFLADEN OVERFØRES TIL REGNVANDET I EN KONCENTRATION SVARENDE TIL
MÆRNINGSKONCENTRATIONEN, SÅ LÆNGE DER ER PESTICID NOK TIL AT OPRETHOLDE
MÆTNINGSKONCENTRATIONEN I VANDET. I OVERLAND COMPARTMENT FORDELES PESTICIDET MELLEM DE
TRE MULIGE TILSTANDE. SOM KONSEKVENS AF DENNE PROCEDURE ER MÆNGDEN AF MOBILT PESTICID
BEGRÆNSET AF OPLØSELIGHEDEN AF PESTICIDET.
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