Effects of heating and post-heating equilibration times on soil water repellency
S. H. Doerr A D , P. Douglas B , R. C. Evans B , C. P. Morley B , N. J. Mullinger B , R. Bryant C and R. A. Shakesby AA Department of Geography, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
B Department of Chemistry, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
C School of Chemical Engineering, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
D Corresponding author. Email: S.Doerr@Swansea.ac.uk
Australian Journal of Soil Research 43(3) 261-267 https://doi.org/10.1071/SR04092
Submitted: 25 June 2004 Accepted: 24 December 2004 Published: 25 May 2005
Abstract
The effects of variation in heating temperature T (50–300°C), heating duration (20–60 min), and post-heating equilibration times (24–168 h at 20°C and 50% relative humidity) on the wettability, as measured by the Critical Surface Tension (CST) method, of 4 initially water repellent soils from Canada, Portugal, and the UK are reported. All soils show an increase in water repellency following heating at temperatures in the range of 50 to 150°C, followed by a considerable decline after heating to 200–250°C, and, except for one soil, the eradication of repellency after heating to 300°C. For two soils with a comparatively high organic carbon content and fine texture, water repellency levels were also affected by the length of the post-heating equilibration period.
The results demonstrate that (i) the common practice of heating samples to 105°C does not provide a viable standard procedure for the measurement of water repellency as it may alter repellency to different degrees, and (ii) where heat treatment is required, a post-heating equilibration time of 24 h is not necessarily sufficient for sample repellency levels to adjust to atmospheric laboratory conditions; therefore it is advisable to prolong equilibration to at least one week prior to measurement.
Additional keywords: hydrophobicity, water repellence, water repellent.
Acknowledgments
This study was supported by EU grant FAIR-CT98-4027, NERC Advanced Fellowship NER/J/S/2002/006622 and Australian Research Council International Linkage Scheme Grant LX0211202. This work does not necessarily reflect the European Commission’s views and in no way anticipates its future policy in this area. The authors are grateful to Julie Roy, Imperial Oil Resources, Alberta, Canada, for kindly providing sample material ‘CA’ and related information.
Carter DJ, Hetherington RE, Morrow G, Nicholson D
(1994) Trends in water repellency measurements from soils sampled at different soil moisture and land use. ‘Proceedings of the 2nd National Water Repellency Workshop’. 1–5 August 1994.. (Ed. DJ Carter ,
KMW Howes )
pp. 49–57. (Western Australia Department of Agriculture and GRDC: Perth, W. Aust.)
Chandler C, Cheney P, Thomas P, Trabaud L, Williams D
(1983) Fire effects on soil, water and air. ‘Fire in forestry. Vol. I. Forest fire behaviour and effects’. (John Wiley and Sons: New York)
Crockford H,
Topalidis S, Richardson DP
(1991) Water repellency in a dry sclerophyll eucalypt forest—measurements and processes. Hydrological Processes 5, 405–420.
DeBano LF
(1981) Water repellent soils: a state-of-the-art. USDA Forest Service General Technical Report PS W-46, Berkeley, CA.
DeBano LF
(2000) The role of fire and soil heating on water repellency in wildland environments: a review. Journal of Hydrology 231–232, 195–206.
| Crossref | GoogleScholarGoogle Scholar |
DeBano LF, Krammes JS
(1966) Water repellent soils and their relation to wildfire temperatures. International Association of Hydrological Science Bulletin 2, 14–19.
DeBano LF,
Savage SM, Hamilton DA
(1976) The transfer of heat and hydrophobic substances during burning. Soil Science Society of America Journal 40, 779–782.
Dekker LW, Ritsema CJ
(1994) How water moves in a water repellent sandy soil. 1. Potential and actual water repellency. Water Resources Research 30, 2507–2517.
| Crossref | GoogleScholarGoogle Scholar |
Dekker LW,
Ritsema CJ,
Oostindie K, Boersma OH
(1998) Effect of drying temperature on the severity of soil water repellency. Soil Science 163, 780–796.
| Crossref | GoogleScholarGoogle Scholar |
Doerr SH
(1998) On standardising the ‘water drop penetration time’ and the ‘molarity of an ethanol droplet’ techniques to classify soil hydrophobicity: a case study using medium textured soils. Earth Surface Processes and Landforms 23, 663–668.
| Crossref | GoogleScholarGoogle Scholar |
Doerr SH,
Blake WH,
Shakesby RA,
Stagnitti F,
Vuurens SH,
Humphreys GS, Wallbrink P
(2004) Heating effects on water repellency in Australian eucalypt forest soils and their value in estimating wildfire soil temperatures. International Journal of Wildland Fire 13, 157–163.
| Crossref |
Doerr SH,
Dekker LW,
Ritsema CJ,
Shakesby RA, Bryant R
(2002) Water repellency of soils: the influence of ambient relative humidity. Soil Science Society of America Journal 66, 401–405.
Doerr SH,
Ferreira AJD,
Walsh RPD,
Shakesby RA,
Leighton-Boyce G, Coelho COA
(2003) Soil water repellency as a potential parameter in rainfall-runoff modelling: experimental evidence at point to catchment scales from Portugal. Hydrological Processes 17, 363–377.
| Crossref | GoogleScholarGoogle Scholar |
Doerr SH,
Llewellyn CT,
Douglas P,
Morley CP,
Mainwaring KA,
Haskins C,
Johnsey L,
Ritsema CJ,
Stagnitti F,
Allinson G,
Ferreira AJD,
Keizer JJ,
Ziogas AK, Diamantis J
(2005) Extraction of compounds associated with water repellency in sandy soils of different origin. Australian Journal of Soil Research 43, 225–237.
Doerr SH,
Shakesby RA, Walsh RPD
(1998) Spatial variability of soil hydrophobicity in fire prone Eucalyptus and Pine forests, Portugal. Soil Science 163, 313–324.
| Crossref | GoogleScholarGoogle Scholar |
Franco CMM,
Clarke PJ,
Tate ME, Oades JM
(2000) Hydrophobic properties and chemical characterisation of natural water repellent materials in Australian sands. Journal of Hydrology 231–232, 47–58.
| Crossref | GoogleScholarGoogle Scholar |
Franco CMM, Tate ME, Oades JM
(1994) The development of water-repellency in sands: Studies on the physico-chemical and biological mechanisms. ‘Proceedings of the 2nd National Water Repellency Workshop’. 1–5 August 1994. (Ed. DJ Carter ,
KMW Howes )
pp. 18–30. (Western Australia Department of Agriculture and GRDC: Perth, W. Aust.)
Giovannini G
(1994) The effect of fire on soil quality. ‘Selection of Papers from the International Conference on Soil Erosion and Degradation as a Consequence of Forest Fires 1991, Barcelona, Spain’. (Ed. M Sala ,
JF Rubio )
pp. 15–27. (Geoforma Ediciones: Logroño, Spain)
Jackson, ML (1958).
‘Soil chemical analysis.’ (Prentice-Hall: Engelwood Cliffs, NJ)
King PM
(1981) Comparison of methods for measuring severity of water repellence of sandy soils and assessment of some factors that affect its measurement. Australian Journal of Soil Research 19, 275–285.
| Crossref | GoogleScholarGoogle Scholar |
Krammes JS, DeBano LF
(1965) Soil wettability: A neglected factor in watershed management. Water Resources Research 1, 283–286.
Letey J
(1969) Measurement of contact angle, water drop penetration time, and critical surface tension. ‘Proceedings of the Symposium on Water Repellent Soils’. 6–10 May 1968. (Ed. LF DeBano ,
J Letey )
pp. 43–47. (University of California: Riverside, CA)
Morley CP,
Mainwaring K,
Doerr SH,
Douglas P,
Llewellyn CT, Dekker LW
(2005) Organic compounds at different depths in a sandy soil and their role in water repellency. Australian Journal of Soil Research 43, 239–249.
Nakaya N
(1982) Water repellency in soils. Japan Agricultural Research Quarterly 16, 24–28.
Robichaud PR, Hungerford RD
(2000) Water repellency by laboratory burning of four northern Rocky Mountain forest soils. Journal of Hydrology 231–232, 207–219.
| Crossref | GoogleScholarGoogle Scholar |
Roy JL, McGill WB
(2002) Assessing soil water repellency using the molarity of ethanol droplet (MED) test. Soil Science 167, 83–97.
| Crossref | GoogleScholarGoogle Scholar |
Roy JL,
McGill WB, Rawluk MD
(1999) Petroleum residues as water-repellent substances in weathered nonwettable oil-contaminated soils. Canadian Journal of Soil Science 79, 367–380.
Savage SM
(1974) Mechanism of fire-induced water repellency in soil. Soil Science Society of America Proceedings 38, 652–657.
Savage SM,
Osborn J,
Letey J, Heaton C
(1972) Substances contributing to fire-induced water repellency in soils. Soil Science Society of America Proceedings 36, 674–678.
Scholl DB
(1975) Soil wettability and fire in Arizona chaparral. Soil Science Society of America Proceedings 39, 356–361.
Valat B,
Jouany C, Rivière LM
(1991) Characterization of the wetting properties of air-dried peats and composts. Soil Science 152, 100–107.
