Water displacement by surfactant solution: an experimental study to represent wastewater loss from sewers to saturated soil

Abstract

Leakage of wastewater from sewer lines may result in contamination of soil and groundwater. Our investigation dealt with the effects of surfactant as one of the constituents of wastewater on the infiltration process of wastewater through soil. To that aim, in a laboratory experiment, a column was uniformly packed with glass beads of 0.25-0.50 mm diameter and equipped with sensors to measure local fluid pressure at three observation points along the direction of flow. The artificial laboratory wastewater was created by adding a commercially available detergent to degassed tap water producing surfactant concentrations between 8 and 16 mg l -1 . The displacement process of degassed tap water by such a particle-free artificial wastewater was studied by loading the surfactant solution into the saturated glass beads column. Short-term pressure changes were observed while the interface between water and surfactant solution passed the observation points within the column. The pressure peaks increased for higher surfactant concentrations. The theory of growing interface between surfactant solution and clean water by aggregation of monomers to a double layer could be supported by the column experiments.

Influence of Anionic Surfactant on Saturated Hydraulic Conductivity of Loamy Sand and Sandy Loam Soils

“…This colmation layer usually has a thickness ranging from millimeters to centimeters [42][43][44], with a perpetual and extremely low permeability [33]. This low permeability has been traditionally attributed to pore clogging caused by organic particles contained in sewage [45].…”

“…Moreover, previous studies emphasized elucidating the overall K s of the columns, with little data derived on the variation of the K s profile. Thus in this study, we sought to examine the influence of the anionic surfactant, which is the most widely used surfactant in industry [12,33], on the K s of various soil types and, more importantly, to assess the K s responses in soils with difference distances from the injection point of the surfactant.…”