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Dense nonaqueous phase liquids (DNAPLs) prevent remediation of contaminated aquifers by preventing the solubilization and mobilization of residual NAPL. A new method that increases the efficiency of NAPL removal and surfactant recovery involves the use of nonionic surfactants such as Triton X-100. The technology promotes the removal of residual NAPL by improving macroemulsion transport. Mathematic models describing the technology are included.

The effectiveness of cosolvents in removing dense nonaqueous phase liquids (DNAPLs) at residual saturation within porous media is evaluated. The results showed that methanol flushing caused the mobilization, non-equilibrium dissolution and flow bypassing of tetrachloroethylene. Small-scale heterogeneities can lead to high residual DNAPL saturations which lend themselves easily to mobilization.

Experiments were carried out to determine the spatial and temporal distributions of basaltic pyroclastic materials subjected to physicochemical weathering. The experiments involved the analysis of 17 elements of pyroclastic materials from Mt. Fuji, Japan, using a multivariate statistical method and two weathering indices. Results show that the concentration of mobile elements can be taken as a function of time and the distance of the materials from the volcano.

The measurement of several polycyclic aromatic hydrocarbons partitioned from eight coal tar samples from manufactured gas plants (MGPs) into water is discussed. Raoult's law convention for activity coefficients and hypothetical supercooled liquid solubilities were used to evaluate the measured partition coefficients. Results indicate that solubility primarily determined the release of PAH from coal tar disposed at MGP sites.