Minimizing losses of nonionic and anionic surfactants to a montmorillonite saturated with calcium using their mixtures

Clay mineral dependent desorption of pyrene from soils by single and mixed anionic–nonionic surfactants

“…6). This result was consistent with previous studies [50,51]. Strong sorption of SDBS by kaolin at different mass ratios was similar to what was seen for the sorption of SDBS by montmorillonite (Fig.…”

“…In contrast, at a mass ratio of 5:5, the percentage of sorbed SDBS on soil C increased significantly initially and then declined. Stellner [27] and Yang [50] reported that when the equilibrium SDBS concentrations is 1.5-fold above the CMC, the precipitates of SDBS redissolve leading to reduced SDBS sorption onto soils by counterion binding of Ca 2+ from Ca-montmorillonite into mixed micelles.…”

Surfactant-enhanced remediation of organic contaminated soil and water

“…6) SDBS sorbed sharply to a maximum at its equilibrium concentration about 1.5 CMC (∼ 1400 mg/L) and then decreased rapidly to zero when equilibrium concentration is about to that of maximum. The shape of the isotherm is similar to that of precipitation curve between SDBS and Ca 2+ in CaCl 2 solution as the precipitation of Ca(DBS) 2 appears to be the primary mechanism for the sorption of SDBS [57,58]. In further, X-ray diffraction (XRD) study shows SDBS could not enter into the interlayer of the montmorillonite.…”

“…There are several studies on the adsorption of anionic surfactants on soil [45][46][47][48][49][50][51] or soil constituents like alumina [52][53][54][55], clay [56][57][58], sediment [59][60][61]. Among the anionic surfactants, LAS is the surfactant used extensively in detergents in throughout the world because of its effectiveness, versatility, cost/performance ratio and environmental safety.…”

Effect of SDBS–Tween 80 mixed surfactants on the distribution of polycyclic aromatic hydrocarbons in soil–water system

“…Due to sorption of surfactants on soil, the effective concentration of surfactants in solution to solubilize organic contaminants decreased and the hydrophobicity and organic carbon content of soil increased, which facilitated the sorption of organic contaminants to soil (Lee et al 2000;Paria and Yuet 2006;Zheng and Obbard 2002). The precipitation of SDBS with mineral ions in soil such as Ca 2+ appears to be the primary mechanism for the sorption of SDBS onto soil (Yang et al 2005(Yang et al , 2007, while hydrogen bonding may be considered as the major driving force for nonionic surfactants' sorption onto soil (Mathur and Moudgil 1998). As a result, anionic-nonionic mixed surfactant could mutually decrease their sorption on soil, hence increasing the effective surfactant concentration in solution, which was beneficial for desorption of PAHs from soil to aqueous phase.…”