Institute of New Energy Chemistry and Environmental Science, College of Chemistry & Chemical Engineering, Northeast Petroleum University, Daqing 163318, China.
Int J Mol Sci. 2019 Apr 15;20(8):1857. doi: 10.3390/ijms20081857.
Fracturing wastewater is often highly emulsified, viscous, and has a high chemical oxygen demand (COD), which makes it difficult to treat and recycle. Ferrate(VI) is a green oxidant that has a high redox potential and has been adopted for the efficient oxidation of fracturing wastewater to achieve triple effects: demulsification, visbreaking, and COD removal. Firstly, optimal conditions were identified to build a model for fast and efficient treatment. Secondly, wastewater treatment using ferrate oxidation was investigated via demulsification, visbreaking, and COD removal. Finally, a mechanism for ferrate oxidation was proposed for the three effects using Fourier-transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The theoretical and experimental data demonstrated that the ferrate oxidation achieved the three desired effects. When ferrate was added, the demulsification efficiency increased from 56.2% to 91.8%, the total viscosity dropped from 1.45 cp to 1.10 cp, and the total removal rate of COD significantly increased to 74.2%. A mechanistic analysis showed that the strongly-oxidizing ferrate easily and efficiently oxidized the O/W interfacial film materials, viscous polymers, and compounds responsible for the COD, which was a promising result for the triple effects.
压裂返排废水通常具有高度乳化、高粘性和高化学需氧量（COD）的特点，这使得处理和回收变得困难。高铁酸盐（VI）是一种绿色氧化剂，具有较高的氧化还原电位，已被用于有效氧化压裂返排废水，以实现三重效果：破乳、降粘和 COD 去除。首先，确定了最佳条件，以建立快速高效处理的模型。其次，通过破乳、降粘和 COD 去除来研究高铁酸盐氧化处理废水。最后，利用傅里叶变换红外（FT-IR）光谱和扫描电子显微镜（SEM）提出了高铁酸盐氧化对这三种效果的作用机制。理论和实验数据表明，高铁酸盐氧化实现了这三种预期效果。当添加高铁酸盐时，破乳效率从 56.2%提高到 91.8%，总粘度从 1.45 cp 降低到 1.10 cp，COD 的总去除率显著提高到 74.2%。机理分析表明，强氧化性的高铁酸盐容易且有效地氧化了 O/W 界面膜材料、粘性聚合物和 COD 相关化合物，这是三重效果的一个有前途的结果。
