Yang Chaoge, Zhang Chunpeng, Liu Fangyuan, Dong Jun
Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, China; Jilin Provincial Key Laboratory of Water Resources and Water Environment, Jilin University, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, China.
Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, China; Jilin Provincial Key Laboratory of Water Resources and Water Environment, Jilin University, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, China.
J Hazard Mater. 2024 Dec 5;480:135776. doi: 10.1016/j.jhazmat.2024.135776. Epub 2024 Sep 8.
Density-modification remediation of dense nonaqueous phase liquid (DNAPL) using colloidal biliquid aphron (CBLA) is an efficient means of enhancing flushing and avoiding the risk of downward migration of DNAPL. However, the use of demulsifier is currently necessary for CBLA to achieve density modification. This leads to issues such as low modification efficiency and the risk of secondary contamination. In this work, we developed a self-demulsifying CBLA (PO-CBLA-S) for density-modification remediation of DNAPL, eliminating the need for external demulsifiers. The self-demulsification process exhibited pseudo-secondary reaction kinetics, achieving densities below 1 g/cm for various DNAPLs. Groundwater chemistry parameters (pH, anions, cations, temperature, and humic acid (HA) content) were investigated for their impact on perchloroethylene (PCE) density modification. Cations were found to enhance PO-CBLA-S density modification more than anions. Both strong acidic and alkaline environments promote the density regulation of PCE by PO-CBLA-S, and temperature positively correlates with the efficiency of density modification. High concentrations of HA also have a favorable facilitating effect on the density modification. The mechanisms of self-demulsifying density modification were clarified at the microscale. Surfactant entanglement caused by internal surfactant-solvent interaction decreased the stability of PO-CBLA-S, leading to self-demulsification. This study addresses density modification challenges and provides a theoretical foundation for its groundwater remediation applications.
使用胶体双液相泡（CBLA）对致密非水相液体（DNAPL）进行密度改性修复是增强冲洗效果并避免DNAPL向下迁移风险的有效方法。然而，目前CBLA实现密度改性需要使用破乳剂。这导致了改性效率低和二次污染风险等问题。在这项工作中，我们开发了一种用于DNAPL密度改性修复的自破乳CBLA（PO-CBLA-S），无需外部破乳剂。自破乳过程呈现准二级反应动力学，可使各种DNAPL的密度低于1 g/cm³。研究了地下水化学参数（pH值、阴离子、阳离子、温度和腐殖酸（HA）含量）对全氯乙烯（PCE）密度改性的影响。发现阳离子比阴离子更能增强PO-CBLA-S的密度改性。强酸性和碱性环境均促进PO-CBLA-S对PCE的密度调节，且温度与密度改性效率呈正相关。高浓度的HA对密度改性也有良好的促进作用。在微观尺度上阐明了自破乳密度改性的机制。内部表面活性剂 - 溶剂相互作用引起的表面活性剂缠结降低了PO-CBLA-S的稳定性，导致自破乳。本研究解决了密度改性挑战，并为其在地下水修复中的应用提供了理论基础。
