اثر آلودگي نفتي بر ويژگي هاي هيدروليكي، آب قابل استفاده و آب گريزي خاك در بختيار دشت اصفهان

چكيده انگليسي :

011 Effect of petrolium contamination on soil hydraulic properties available water and water repellency in Bakhtiardasht Isfahan Mahdieh Kermanpour mahdiehkermanpour@yahoo com Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiM R Mosaddeghi mosaddeghi @cc iut ac irAbstractPetroleum pollution is an important environmental problem in countries with oil industry In addition tothe harmful effects on human health petroleum pollution impacting soil and water resources and naturalecosystems could adversely affect living organisms especially plants This study was done to investigatethe effects of petroleum pollution on soil hydraulic properties and water repellency in Bakhtiardashtregion Isfahan Polluted locations with various soil texture and oil concentration total petroleumhydrocarbons TPHs in the range of 2 10 and adjacent non polluted locations were selected to berepresentative in the green space around the Isfahan Oil Refinery In the first part the impact of soilpetroleum pollution on in situ unsaturated infiltration and soil hydraulic properties was evaluated usingtension infiltrometer at four consecutive matric suctions 15 10 5 and 2 cm Soil hydraulic parameterswere then predicted using Wooding s analytical and DISC numerical methods Persistence of soil waterrepellency was assessed using water drop penetration time WDPT and soil structural stability wasevaluated using the wet sieving method and mechanically dispersible clay MDC The data wereanalyzed using two way ANOVA of 4 soil texture groups and 4 levels of petroleum contamination none TPHs of zero low TPHs of 1 3 moderate TPHs of 3 6 high TPHs 6 with dissimilarreplicates In the second part which was done in the laboratory petroleum pollution of water well waterin the region was also considered in addition to the aged petroleum pollution of the soils Soil sampleswith specific degree of compactness 80 of the reference bulk density were repacked The soils werewetted and dried for 13 cycles using unpolluted and petroleum polluted waters Then saturated hydraulicconductivity Ks and water characteristic curve of the soil samples were measured using constant headmethod and at 16 matric suctions respectively The soil water characteristic data were modeled using vanGenuchten and Durner dual porosity models and soil hydraulic parameters were predicted Furthermore pore size distribution Dexter s physical quality index SDexter and soil available water for plant AW were calculated Several indices for soil water repellency were measured calculated using molarity ofethanol droplet MED capillary rise method CRM and intrinsic sorptivity of water ethanol Results ofthe first part showed that cumulative infiltration into the soil was significantly decreased due to petroleumpollution Likewise petroleum pollution significantly reduced Ks and near saturated hydraulicconductivity soil sorptivity S and steady state flow rate q at all matric suctions Results of numericalanalysis also indicated that petroleum pollution significantly decreased Ks and saturated s and near saturated water contents Overall petroleum pollution up to TPHs of 6 did not considerably affect waterinfiltration and soil hydraulic properties but high pollution TPHs 6 could significantly alter theseproperties A positive and significant relation was found between log WDPT and TPHs independent ofsoil texture i e TPHs clay Presence of petroleum hydrocarbons in soil significantly increased the water stable aggregates and decreased MDC Results of the second part showed that petroleum pollution of soiland water intensified soil hydrophobicity i e significant increase in soil water contact angle and waterrepellency indices Through increased stability of pores and macroporosity petroleum pollution resultedin significant and non significant increase of s and Ks respectively Besides the SDexter was significantlyincreased as a result of petroleum pollution Despite greater s and SDe

كرمانپور، مهديه

اثر آلودگي نفتي بر ويژگي هاي هيدروليكي، آب قابل استفاده و آب گريزي خاك در بختيار دشت اصفهان

نفوذ غير اشباع , منحني مشخصه ي رطوبتي خاك , توزيع اندازه منافذ , آب قابل استفاده