The histogramindicatedthattheresidualdieselconcentra-
tions progressivelydecreasedinthecontrolsoilandtheHDMs
soils, howeverthereductionamountofvarioussampleswas
different for30and60daysexperiments.Theresidualcontents
of dieselpollutantsinmostHDMstreatmentsaresignificantly