Details
| Original language | English |
|---|---|
| Pages (from-to) | 392-403 |
| Number of pages | 12 |
| Journal | Journal of Hydrology and Hydromechanics |
| Volume | 68 |
| Issue number | 4 |
| Publication status | Published - 1 Dec 2020 |
Abstract
Microinfiltrometers to assess soil water repellency (SWR) are limited to small tension ranges and have different technical setups, hindering a comparison between results from different laboratories. Hence, a microinfiltrometer which considers various aspects like extent and persistence of SWR is needed. The technical update suggested here uses glass tubes (e.g., 3 mm inner diameter), a fabric of mesh size 15 μm around the tip to enable good contact between soil surface and tip, ultrapure degassed water, and an evaporation protection for tip and reservoir during long-term infiltration. The adjustment of a continuous range of pressures and tensions (i.e., +0.5 to -40 cm) was done using glass tubes of various lengths connected to the tip. Three soil samples with initial contact angles, CA, of 18°, 62°, and 91° after 25°C treatment were additionally treated at 80°C to increase SWR persistence and CA. The soil particle interface chemical composition was determined by X-ray photoelectron spectroscopy (XPS). The hydrophysical properties evaluated included water and ethanol sorptivity as well as very important aspects of SWR, i.e. water drop penetration time, water repellency cessation time, repellency index, and modified repellency index. The results derived from the technically modified microinfiltrometer setup showed consistent differences between initial wettability and the water repellency cessation time as a parameter describing the development of SWR with time. The interface O/C ratio as derived from XPS data was negatively correlated with CA (p <0.05), thus proving the close relationship between interface chemistry and wettability. Our findings illustrated a strong positive correlation (R2 = 0.99, p < 0.05) between sorptivity and O/C ratio under -2 cm tension which can be considered as the universal tension for different aspects of SWR.
Keywords
- Ethanol, Infiltration, Interface chemistry, Sorptivity, Thermal treatment, X-ray photoelectron spectroscopy
ASJC Scopus subject areas
- Environmental Science(all)
- Water Science and Technology
- Engineering(all)
- Mechanical Engineering
- Chemical Engineering(all)
- Fluid Flow and Transfer Processes
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In: Journal of Hydrology and Hydromechanics, Vol. 68, No. 4, 01.12.2020, p. 392-403.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Development of a universal microinfiltrometer to estimate extent and persistence of soil water repellency as a function of capillary pressure and interface chemical composition
AU - Sepehrnia, Nasrollah
AU - Woche, Susanne K.
AU - Goebel, Marc O.
AU - Bachmann, Jörg
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Microinfiltrometers to assess soil water repellency (SWR) are limited to small tension ranges and have different technical setups, hindering a comparison between results from different laboratories. Hence, a microinfiltrometer which considers various aspects like extent and persistence of SWR is needed. The technical update suggested here uses glass tubes (e.g., 3 mm inner diameter), a fabric of mesh size 15 μm around the tip to enable good contact between soil surface and tip, ultrapure degassed water, and an evaporation protection for tip and reservoir during long-term infiltration. The adjustment of a continuous range of pressures and tensions (i.e., +0.5 to -40 cm) was done using glass tubes of various lengths connected to the tip. Three soil samples with initial contact angles, CA, of 18°, 62°, and 91° after 25°C treatment were additionally treated at 80°C to increase SWR persistence and CA. The soil particle interface chemical composition was determined by X-ray photoelectron spectroscopy (XPS). The hydrophysical properties evaluated included water and ethanol sorptivity as well as very important aspects of SWR, i.e. water drop penetration time, water repellency cessation time, repellency index, and modified repellency index. The results derived from the technically modified microinfiltrometer setup showed consistent differences between initial wettability and the water repellency cessation time as a parameter describing the development of SWR with time. The interface O/C ratio as derived from XPS data was negatively correlated with CA (p <0.05), thus proving the close relationship between interface chemistry and wettability. Our findings illustrated a strong positive correlation (R2 = 0.99, p < 0.05) between sorptivity and O/C ratio under -2 cm tension which can be considered as the universal tension for different aspects of SWR.
AB - Microinfiltrometers to assess soil water repellency (SWR) are limited to small tension ranges and have different technical setups, hindering a comparison between results from different laboratories. Hence, a microinfiltrometer which considers various aspects like extent and persistence of SWR is needed. The technical update suggested here uses glass tubes (e.g., 3 mm inner diameter), a fabric of mesh size 15 μm around the tip to enable good contact between soil surface and tip, ultrapure degassed water, and an evaporation protection for tip and reservoir during long-term infiltration. The adjustment of a continuous range of pressures and tensions (i.e., +0.5 to -40 cm) was done using glass tubes of various lengths connected to the tip. Three soil samples with initial contact angles, CA, of 18°, 62°, and 91° after 25°C treatment were additionally treated at 80°C to increase SWR persistence and CA. The soil particle interface chemical composition was determined by X-ray photoelectron spectroscopy (XPS). The hydrophysical properties evaluated included water and ethanol sorptivity as well as very important aspects of SWR, i.e. water drop penetration time, water repellency cessation time, repellency index, and modified repellency index. The results derived from the technically modified microinfiltrometer setup showed consistent differences between initial wettability and the water repellency cessation time as a parameter describing the development of SWR with time. The interface O/C ratio as derived from XPS data was negatively correlated with CA (p <0.05), thus proving the close relationship between interface chemistry and wettability. Our findings illustrated a strong positive correlation (R2 = 0.99, p < 0.05) between sorptivity and O/C ratio under -2 cm tension which can be considered as the universal tension for different aspects of SWR.
KW - Ethanol
KW - Infiltration
KW - Interface chemistry
KW - Sorptivity
KW - Thermal treatment
KW - X-ray photoelectron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85094923632&partnerID=8YFLogxK
U2 - 10.2478/johh-2020-0035
DO - 10.2478/johh-2020-0035
M3 - Article
AN - SCOPUS:85094923632
VL - 68
SP - 392
EP - 403
JO - Journal of Hydrology and Hydromechanics
JF - Journal of Hydrology and Hydromechanics
SN - 0042-790X
IS - 4
ER -