Jerzy Weber

and 3 more

This paper present results on soil contamination with petroleum hydrocarbons (PHs) on soil sorptivity and hydrophobicity under different soil moistures. The micro-infiltrometer method was used in laboratory experiment to determine the soil water repellency index (R) and the water drop penetration time (WDPT) test. The increase in PHs contamination contributed to soil repellency and caused a decrease in water sorptivity. The negative effect of contamination with PHs on soil sorptivity depended on soil moisture and was marked especially clearly after exceeding the critical moisture threshold. However, contamination by PHs did not reveal significant changes when ethanol was used instead of water. The R index and the WDPT test revealed a similar trend, inversely related to the level of soil contamination with PHs. The total amount of water available to plants in non-contaminated soil was 19.04%, while contamination equal to 100 g kg -1 caused a decrease to 6.36%. Hydrophobization of water-conducting pore surfaces by petroleum hydrocarbons severely reduced infiltration and destroyed the existing hydrological system of naturally hydrophilic soil. The almost three-fold decrease in total amount of water has a fundamental influence on increasing the risk of soil drought. The soil water repellency causes a decrease in resistance to droughts and slows the alimentation process of soil water retention. The results obtained indicated that the interrelations presented between the level of PHs contamination, soil sorptivity, water repellency, and soil moisture are key to predicting the environmental effects of contamination and effective soil remediation.