title: Accumulation of oil and grease in soils irrigated with greywater and their potential role in soil water repellency.
abstract: The potential impact of oil and grease (O and G) to soils irrigated with greywater (GW) was investigated. Greywater streams were sampled and analyzed for O and G content, along with corresponding GW-irrigated soils. Untreated kitchen GW averaged 200 mg L(-1) O and G, over an order of magnitude more than other GW streams. GW-irrigated soils showed O and G accumulation of up to 200 mg kg(-l) within the first 20-cm of depth. To determine the potential effects of such O and G accumulation on water movement in soil, capillary rise and water drop penetration time (WDPT) experiments were conducted. The results showed up to 60% decrease in capillary rise when sand containing 250 mg kg(-1) O and G was used. Interestingly, no additional reduction in capillary rise was observed at concentrations above 250 mg kg(-1). WDPT was observed to increase linearly with increased O and G content, up to 1000 mg kg(-1). This work demonstrated that O and G in GW used for irrigation can accumulate in soil and may lead to a significant reduction in the soils ability to transmit water.
authors.affiliation: Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Israel.
authors.forename: Micheal J
authors.initials: MJ
authors.lastname: Travis
authors.forename: Noam
authors.initials: N
authors.lastname: Weisbrod
authors.forename: Amit
authors.initials: A
authors.lastname: Gross
mesh_terms: D000383:Agriculture / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D009821:Oils / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009821:Oils; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical