Natural gradient partitioning and interfacial tracer tests for NAPL source zone characterization at a former coal gasification plant

摘要

A natural gradient partitioning and interfacial tracer test (PITT) at a field site near to a former coal gasification plant was validated in situ for the integrated determination of DNAPL (tar oil) amount and distribution. The efficiency of PITTs was tested in controlled laboratory studies (batch, column, tank) under different flow-velocities (1-5 m day~(-1)) and DNAPL distributions (DNAPL coatings, DNAPL blobs, DNAPL pool). The alcohols 4-methyl-2-pentanol, l-hexanol and 2,4-dimethyl-3-pentanol were used as suitable partitioning tracers to measure the DNAPL saturation, while sodium laurylethersulphate, an anionic surfactant, was used as an interfacial tracer to estimate the effective DNAPL-water interfacial area. All PITTs were conducted as pulse-type experiments and the resulting breakthrough curves were analysed by the method of moments.