Soil Sorption of Organic Vapors and Effects of Humidity on Sorptive Mechanism and Capacity

Cary T. Chiou, Thomas D. Shoup

Research output: Contribution to journalArticlepeer-review

324 Citations (Scopus)


Vapor sorption isotherms on dry Woodburn soil at 20-30 °C were determined for benzene, chlorobenzene, p-di-chlorobenzene, m-dichlorobenzene, 1,2,4-trichlorobenzene, and water as single vapors and for benzene, m-dichlorobenzene, and 1,2,4-trichlorobenzene as functions of relative humidity (RH). Isotherms for all compounds on dry soil samples are distinctively nonlinear, with water showing the greatest capacity. Water vapor sharply reduced the sorption capacities of organic compounds with the dry soil; on water-saturated soil, the reduction was about 2 orders of magnitude. The markedly higher sorption of organic vapors at subsaturation humidities is attributed to adsorption on the mineral matter, which predominates over the simultaneous uptake by partition into the organic matter. At about 90% RH, the sorption capacities of organic compounds become comparable to those in aqueous systems. The effect of humidity is attributed to adsorptive displacement by water of organics adsorbed on the mineral matter. A small residual uptake is attributed to the partition into the soil-organic phase that has been postulated in aqueous systems. The results are essentially in keeping with the model that was previously proposed for sorption on the soil from water and from organic solvents.

Original languageEnglish
Pages (from-to)1196-1200
Number of pages5
JournalEnvironmental Science and Technology
Issue number12
Publication statusPublished - 1985 Dec 1

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry


Dive into the research topics of 'Soil Sorption of Organic Vapors and Effects of Humidity on Sorptive Mechanism and Capacity'. Together they form a unique fingerprint.

Cite this