[boxfickslawdispersion] Use effDiff values from volVars

lecture/mm/henryproblem/henry1p2c/boxfickslawdispersion.hh

@@ -175,13 +175,10 @@ public:
                 continue;
 
             // effective diffusion tensors
-            using EffDiffModel = GetPropType<TypeTag, Properties::EffectiveDiffusivityModel>;
-            auto insideD = EffDiffModel::effectiveDiffusivity(insideVolVars.porosity(),
-                                                              insideVolVars.saturation(phaseIdx),
-                                                              insideVolVars.diffusionCoefficient(phaseIdx, compIdx));
-            auto outsideD = EffDiffModel::effectiveDiffusivity(outsideVolVars.porosity(),
-                                                               outsideVolVars.saturation(phaseIdx),
-                                                               outsideVolVars.diffusionCoefficient(phaseIdx, compIdx));
+
+            const auto mainCompIdx = FluidSystem::getMainComponent(phaseIdx);
+            auto insideD = insideVolVars.effectiveDiffusionCoefficient(phaseIdx, mainCompIdx, compIdx);
+            auto outsideD = outsideVolVars.effectiveDiffusionCoefficient(phaseIdx, mainCompIdx, compIdx);
 
             // scale by extrusion factor
             insideD *= insideVolVars.extrusionFactor();