Analysis of water retention characteristics of oil-polluted earthy materials with different textures based on van Genuchten model
- 39 Downloads
The water retention characteristics of polluted soil systems are affected not only by the properties of the soil (e.g., texture) but also by those of the pollutants. This study aimed to evaluate the effect of oil pollution on the water-holding capacity of earthy materials with different textures.
Materials and methods
Three earthy materials (Lou, Loessial, and Aeolian sandy earthy materials) with different textures were treated with crude oil at five pollution levels (0, 0.5, 1, 2, and 4%). The soil water retention curve (SWRC) obtained for each treated sample was analyzed using the van Genuchten model.
Results and discussion
Oil pollution resulted in lower soil water retention in each case, with a leftward shift of the corresponding SWRC, and led to a decrease in the saturated water content of the earthy material, characterized by a marked increase in incomplete saturation, and a decrease in the residual water content (i.e., irreducible saturation). Oil pollution also determined a marked increase in the slope of the SWRC. The response of the SWRC to oil pollution was significantly influenced by the texture of earthy material, and the saturated water content of all earthy materials was strongly affected by the level of oil pollution. The residual water content of the heavier-textured Lou earthy material was also strongly affected by the oil pollution level, but no clear influence was found for the lighter-textured Loessial or Aeolian sandy earthy materials. The SWRC slope of the Aeolian sandy earthy material was sensitive to oil pollution, unlike those of the Lou and Loessial earthy materials.
Oil pollution reduced the water-holding capacity of different earthy materials to an extent depending on the soil texture. Under low-suction conditions, a significant effect of oil pollution on earthy materials of different texture was generally observed, while under high-suction conditions, the effect of oil pollution was greater for heavier-textured earthy materials.
KeywordsOil pollution Saturated water content Soil texture Water-holding capacity
Soil water retention curve
- V-G model
van Genuchten model
This study was supported by the Research Project of Shaanxi Provincial Land Engineering Construction Group (DJNY2018-17).
- Chai GQ, Zhao YA, Huang XC, Zhang YQ, Shi XJ (2017) Effects of different carbonaceous conditioners on water retention capacity of purple soil. J Soil Water Conserv 31:296–302,309Google Scholar
- Fetter CW (2011) Contaminant hydrogeology (2nd Edition). (Zhou NQ and Huang Y, Trans.) Beijing: Higher Education Press:154–190 (in Chinese)Google Scholar
- Gao HB, Shao MA (2011) Effect of temperature on soil moisture parameters. Adv Water Resour 22:484–494Google Scholar
- Gao HY, Guo SL, Liu WZ, Li M, Zhang J (2014) Spatial variability of soil water retention curve under fertilization practices in arid-highland of the loess plateau. Trans Soc Agric Mac 45:161–165,176Google Scholar
- Guo XH, Sun XH, Ma JJ (2009) Parametric estimation of the van Genuchten’s equation based on hybrid genetic algorithm. Adv Water Resour 20:677–682Google Scholar
- Han XF, Lv J (1999) Influencing factors of soil water characteristic curve. Cross-Strait Soil and Fertilizer Symposium of China Soil SocietyGoogle Scholar
- Lei ZD (1987) Soil hydrodynamics. Tsinghua University Press, Beijing (in Chinese)Google Scholar
- Liang C (2011) Studies on hydrodynamic characteristics of oil-contaminated aquifer medium. China Ocean University, Qingdao (in Chinese with English abstract)Google Scholar
- Ran YL, Wang YQ, Zhang RX, Zhu FH, Liu J (2015) Research on the mechanism of super absorbent polymer to soil water-holding characteristic. Agric Res Arid Areas 33:101–107Google Scholar
- Schofield RK (1935) Th pF of the water in soil. Trans Int Congr Soil Sci:38–48Google Scholar
- Van Genuchten MT, Leij FJ, Yates SR (1991) The RETC code for quantifying the hydraulic functions of unsaturated soils: project summaryGoogle Scholar
- Wang XH, Jia KL, Liu JH, Li LJ (2009a) Application of van Genuchten model to analysis of soil moisture characteristic curve. Agric Res Arid Areas 27:179–188Google Scholar
- Wu HB, Fang HL, Li AP (2016) Effects of modified materials commonly used on green belt on soil water characteristic. Soils 48:1229–1236Google Scholar
- Xia JW, Wei YJ, Cai CF (2017) Correlations between characteristic curves of physical properties of weathered granite soils. Acta Pedol Sin 54:1–11Google Scholar
- Xu SH, Liu JL (2003) Advances in approaches for determining unsaturated soil hydraulic properties. Adv Water Resour 14:494–501Google Scholar