Experimental Study on the Adsorption Law of Anionic Surfactants in Shield Soil
(1. State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University,Beijing 100084; 2. CCCC-SHEC Third Highway Engineering Co., Ltd., Xi′an 710016)
Abstract:
This paper studies the adsorption and desorption behaviors of anionic surfactant sodium dodecyl sulfate (SDS) on the surface of soil particles in different particle size ranges, analyzes the adsorption and desorption patterns of surfactants in shield soil, measures the changes of zeta potential of soil particles, and investigates the feasibility of rapid determination of SDS adsorption by zeta potential. The results show that the unit equilibrium adsorption capacity of SDS is larger on soil particles with smaller size. The equilibrium adsorption capacity increases with the increase of SDS concentration and the adsorption isotherm is linear when the SDS concentration of the surfactant is less than its critical micellar concentration. The equilibrium adsorption capacity decreases with increasing SDS concentration when the concentration is greater than the critical micelle concentration. The smaller the particle size of the residue, the less effective the SDS desorption. The larger the adsorption capacity of SDS, the lower the desorption rate. It is feasible to determine the surface SDS equilibrium adsorption capacity of soil particles with particle size less than 0.075 mm by measuring their zeta potential.
CAO Yazhou1 WU Zhixiong1 LI Yannan1 HU Liming1 WANG Rui1 ZHANG Xuan2 XIAO Ying2
.Experimental Study on the Adsorption Law of Anionic Surfactants in Shield Soil[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(1): 195-201