Mobilization potential of hydrophobic organic compounds (HOCs) in contaminated soils and waste materials. Part 1. Mobilization potential of PCBs, PAHs, and aliphatic hydrocarbons in the presence of solubilizing substances.
In: Acta Hydrochimica et Hydrobiologica (Acta Hydrochim.Hydrobiol.), Jg. 25 (1997) ; Nr. 5, S. 242-247
Zeitschriftenaufsatz / Fach: Chemie
When using an elution procedure for org. pollutants to est. the leaching behavior of contamined soils and waste deposits, the influence of org. matter in solids and eluates adequately has to be considered. In batch tests with a solid/liq. ratio of 1:10, various aq. solns. were composed, the solubilizing effect of which can be attributed to ubiquitous natural compds. (e.g., phospholipids, humic and carbonic acids). These solns. were evaluated in regard to the mobilization of PAHs, PCBs, and aliph. hydrocarbons in soil and waste samples. The results were compared with batch tests contg. sodium dodecyl sulfate (SDS), the properties and applications of which are selected and optimized in order to simulate the chem. interactions between pollutant and solubilizing substances of natural sources. Under alk. conditions, the part of eluated pollutants was high because of the release of humic substances indigenous to the sample. Low concns. of phospholipids and humic acid could decrease the mobility of aliph. hydrocarbons. The extend of HOC mobilization is affected by specific interdependences between solubilizing substances and reactive matter of the samples. For most samples, 5.0 g/L concd. SDS soln. was able to simulate the most effective natural solutizer potential in regard to the mobilization of PAHs, PCBs, and aliph. hydrocarbons within the system of batch tests. Whereas elution with pure water caused significant deviations in pollutant compn. 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 sep. phases.