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Partitioning and interfacial tracer tests for NAPL source zone characterisation at a former gasification plant
Published in Poul L. Bjerg, Peter Engesgaard, Thomas D. Krom, Groundwater 2000, 2020
M. Piepenbrink, C. Eberhardt, T. Ptak, P. Grathwohl
In-situ PITTs allow the determination of the NAPL amount and distribution in the whole subsurface area, that is flushed during an experiment. This study focuses on the determination of tar oil residual saturations based on PITT. The alcohols Isopropanol (IPA), 2,3-Dimethyl-2-Butanol (2.3DM-2-B), 4-Methyl-2-Pentanol (4-M-2-P), 1-Hexanol (1-HEX) and 2,4-DM-3-Pentanol (2,4-DM-3-P) are suitable partitioning tracers and can easily be detected by GC-FID analysis even in the presence of high contaminant concentrations in the water. Marlinat, an anionic surfactant is used as interfacial tracer and can be analized by IC conductivity measurement. NaCl was used as conservative tracer and was detected by a conductivity electrode.
Reaction of Pentanol isomers with OH radical – A theoretical perspective
Published in Molecular Physics, 2018
Basheer Aazaad, Senthilkumar Lakshmipathi
A saturated aliphatic alcohol, Pentanol has three isomeric forms namely 1-Pentanol, 2-Pentanol and 3-Pentanol. The relative energy analysis of these three molecular entities shows that the 2-Pentanol isomeric form is the most stable form and possesses lower energy than 1-Pentanol and 3-Pentanol isomers by 3.47 and 2.06 kcal/mol, respectively. However, the relative energy difference of three isomeric forms is less than 4 kcal/mol. Hence, they undergo degradation reaction with atmospheric oxidants. The highly reactive atmospheric oxidants like OH, Cl, NO3 radicals react exclusively with oxygenated volatile organic compounds. In the present study, all the three Pentanol isomers are expected to undergo H-atom abstraction reactions rather than OH addition reaction due to the lack of unsaturated double bonds in the parent molecule. The geometries of reactant (R), reactant complexes (RCs), TS, product complexes (PCs) and product (P) were optimised at M06-2X level of theory, and the structures are shown in Supplementary Information Figure S1. The relative energy, enthalpy and Gibbs free energy of the initial reactions of 1-Pentanol, 2-Pentanol and 3-Pentanol, calculated at M06-2X, MPW1K, BHandHLYP, MP2 and CCSD(T) functional with 6-311+G(d,p) basis set, are given in Tables 1–3, respectively.