Mobilisierbarkeit von hydrophoben organischen Schadstoffen in belasteten Böden und Abfällen. Teil I: Mobilisierbarkeit von PCB, PAK und n‐Alkanen durch Lösungsvermittler

When using an elution procedure for organic pollutants to estimate the leaching behaviour of contamined soils and waste deposits, the influence of organic matter in solids and eluates adequately has to be considered. In batch tests with a solid/liquid ratio of 1:10, various aqueous solutions were composed, the solubilizing effect of which can be attributed to ubiquitous natural compounds (e. g., phospholipids, humic and carbonic acids). These solutions were evaluated in regard to the mobilization of PAHs, PCBs, and aliphatic hydrocarbons in soil and waste samples. The results were compared with batch tests containing sodium dodecyl sulfate (SDS), the properties and applications of which are selected and optimized in order to simulate the chemical interactions between pollutant and solubilizing substances of natural sources. Under alkaline conditions, the part of eluated pollutants was high because of the release of humic substances indigenous to the sample. Low concentrations of phospholipids and humic acid could decrease the mobility of aliphatic hydrocarbons. The extend of HOC mobilization is affected by specific interdependences between solubilizing substances and reactive matter of the samples. For most samples, 5.0g/L concentrated SDS solution was able to simulate the most effective natural solutizer potential in regard to the mobilization of PAHs, PCBs, and aliphatic hydrocarbons within the system of batch tests. Whereas elution with pure water caused significant deviations in pollutant composition and too low yields, the use of SDS effected a good conformity. Modified in such a manner, the elution procedure can follow DIN 38414 part 4, when loss of pollutants will be minimized; e. g., centrifugation is needed to separate phases.