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

Abstract

Surfactants released into the terrestrial environment in large amounts can potentially alter the physical, chemical and biological properties of soils, particularly the saturated hydraulic conductivity (K s ). Unfortunately findings regarding this process are quite limited. In this study, column tests were used to analyze the effects of Aerosol 22, a widely used anionic surfactant, on K s of loamy sand and sandy loam soils. Solutions were injected into columns from the bottom with controlled pressure heads. Both the overall K s of columns and the K s of 6 layers at distances of 0-1 cm, 1-3 cm, 3-5 cm, 5-7 cm, 7-9 cm, and 9-10 cm from the bottom, were continuously monitored before and after the surfactant injections. Results showed that the overall K s of all columns decreased after 2-4 pore volumes of the surfactant injections. However, stabilization and even increase at the beginning of the surfactant injection was also observed due to the different K s variations in different layers. Specifically, a surfactant injection of 2-4 pore volumes continuously decreased the K s of the 0-1 cm layers which yielded a K s reduction of two orders of magnitude and dominated the K s variations of the column. In contrast, an increase in the K s of the 1-3 cm and 3-5 cm layers was more likely, while K s variation of the 5-10 cm layers was less likely. We hypothetically attributed the K s variations to the swelling of clay, the collapse of soil aggregates and subsequent particle displacements from surfactant adsorption, which caused pore clogging in the bottom 0-1 cm layer and higher porosities in the layers above. The adsorption of the surfactant aggregates and crystallization were also possibly thought to cause a pore clogging in the bottom layer thus decrease the surfactant concentration from the inlet, the severity of which affects these layers less at greater distances from the inlet. In view of the uncertainty showed by the experimental results, we also suggest to include more replicate columns in future studies, so as to increase the repeatability of the measurements.

Fate and transport of Cryptosporidium parvum oocysts in repacked soil columns: Influence of soil properties and surfactant

“…This low permeability value of the colmation layer is the result of soil pores being clogged by the organic compound, the surfactant Aerosol 22. The formation of a colmation layer and soil pore clogging were reported in a study investigating the effect of anionic surfactant Aerosol 22 on saturated hydraulic conductivity of these same loamy sand (Sparta and Gilford series) and sandy loam (Lewsiton and Greenson series) soils (Peng et al., 2017). In addition, as the soil columns underwent slicing, the crystallization of the surfactant in soil was observed in the top soil layer.…”

Assessment of industrial effluent impacts on soil physiochemical properties in Kwashe Industrial Area, Iraq Kurdistan Region.

“…Soil EC in this area is highly affected by the discharge of industrial effluents as it dissolves salts in the soil and found to be in the same range in the sites as shown in table 2. High concentration of EC in soil causing excessive particles to wash away from the soil due to decline surface tension, large pores and a high EC in the soil will allow more pollutants to enter the soil, resulting in increased groundwater pollution [16,49]. These research in the line with the [16] who indicated that Soil irrigation with a detergent effluent would raise the electrical conductivity (EC) of the soil, which increases salinity of soil in the long time.…”

Surfactant pollution, an emerging threat to ecosystem: Approaches for effective bacterial degradation

“…Due to their massive consumption in various industries and households, a relatively high concentration of surfactants is reported in sediments (Li et al, 2018), surface waters (D'Agostino & Mabury, 2017; Munoz et al, 2017), soil and sludge (Abril et al, 2020; Gomez et al, 2011; Jardak et al, 2016). As a component of greywater, surfactants have been identified to cause water repellence and a decrease in the hydraulic conductivity of soil (Lado & Ben‐Hur, 2009; Peng et al, 2017; Travis et al, 2010). Increased foaming of the water bodies and changes in several physicochemical properties of soil are two major effects of the surface‐active agents on the abiotic environment.…”

“…Alteration in the optimum soil pH will pose a threat to the soil's biological activity (Anwar, 2011; Chirani et al, 2021). In a study to investigate the effects of common household surfactants on hydraulic conductivity, sorptivity, penetration and soil stability, it was observed that the application of surfactants resulted in a reduction in hydraulic conductivity (Abu‐Zreig et al, 2003; Peng et al, 2017). Also, the magnitude of hydraulic conductivity is dependent on the soil texture, type of surfactant and concentration.…”