Zeng Guilu, Yang Rumin, Tian Shuang, Zhou Zelong, Wang Qi, Yu Xiu, Fu Rongbing, Lyu Shuguang
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
Center for Environmental Risk Management & Remediation of Soil & Groundwater, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
J Hazard Mater. 2022 Jul 15;434:128803. doi: 10.1016/j.jhazmat.2022.128803. Epub 2022 Apr 8.
In this work, the effect of different desorbents (low molecular weight organic acids (LMWOAs), surfactants, and inorganic salts) on naphthalene (NAP) desorption in soil was investigated, and the results showed that NAP desorption pattern fitted the pseudo-second-order kinetics. The addition of LMWOAs, especially citric acid (CA), could stimulate the reactive oxygen species (ROS) generation and NAP degradation in Fe(II) activated persulfate (PS) system, while the presence of surfactants and CaCl could inhibit the NAP removal due to the competitive consumption of ROS. The maximum removal of NAP was 97.5% within 120 min at the PS/Fe(II)/CA/NAP molar ratio of 15/5/1/1, and the pseudo-first-order kinetic constant of NAP removal increased from 0.0110 min to 0.0783 min with the addition of CA. Compared with surfactants and inorganic salts, LMWOAs, especially CA, were more suitable as desorbent in soil washing coupled with in situ chemical oxidation technique. Moreover, 1.86 mg L desorbed amount and 36.1% removal of NAP from soil could be obtained with the presence of 1 mM CA. Finally, the significant removal of NAP and other contaminants (phenanthrene, fluoranthene, and benzene series) in actual groundwater could provide theoretical basis and technical support for the remediation of organic contaminated sites with desorbents.
