000309614 001__ 309614
000309614 005__ 20240928181519.0
000309614 0247_ $$aG:(GEPRIS)40956159$$d40956159
000309614 035__ $$aG:(GEPRIS)40956159
000309614 040__ $$aGEPRIS$$chttp://gepris.its.kfa-juelich.de
000309614 150__ $$aElucidating mechanisms of pesticide sorption and degradation by compound specific isotope analysis in conjunction with advanced mathematical transport modelling$$y2007 - 2016
000309614 371__ $$aProfessor Dr. Martin Elsner
000309614 450__ $$aDFG project G:(GEPRIS)40956159$$wd$$y2007 - 2016
000309614 5101_ $$0I:(DE-588b)2007744-0$$aDeutsche Forschungsgemeinschaft$$bDFG
000309614 550__ $$0G:(GEPRIS)31907460$$aSPP 1315: Biogeochemical Interfaces in Soil$$wt
000309614 680__ $$aBiogeochemical interfaces play a key role for retardation and elimination of organic pesticides: (i) as sorption medium for retention; (ii) by harbouring microorganisms that facilitate degradation. Tracing these processes under natural conditions in the absence of mass balances is difficult. Of particular concern are polar and anionic pesticides because they are highly mobile. This proposal aims to provide two important, new contributions towards a better process understanding, each focussed in one Ph.D. project:(1) Measurements of compound-specific 13C and 15N isotope fractionation to investigate pesticide sorption and degradation. We will for the first time (a) measure degradation-associated isotope fractionation for bentazone and MCPA, as a new approach to detecting their transformation in natural systems; (b) use the isotope effect between the neutral and anionic form of bentazone to characterize directly which form (neutral versus ionic) is preferentially retained at geochemical surfaces (pure minerals, artificial and natural soils).(2) Column studies in conjunction with cutting-edge mathematical modelling to assess the role of immobile water on sorption and degradation. We aim to test the hypotheses that (a) surface interactions of pesticides are more pronounced when more of the substances are present in immobile (= stagnant, near-surface) water, and (b) that this proportion is greater under unsaturated conditions. To this end, (i) tracer tests (3H, bromide) at different degrees of water content will quantify the proportions of mobile versus immobile water at different degrees of saturation; (ii) an advanced mathematical model including slow, irreversible sorption, and rapid sorption equilibrium in the immobile water zone will be developed to describe for the first time the influence of immobile water on pesticide sorption and degradation.
000309614 909CO $$ooai:juser.fz-juelich.de:976489$$pauthority$$pauthority:GRANT
000309614 909CO $$ooai:juser.fz-juelich.de:976489
000309614 980__ $$aG
000309614 980__ $$aAUTHORITY