摘要
The efficient separation of oil from complex industrial wastewaters, particularly hydraulic fracturing flowback, remains a critical environmental challenge. This study presents an innovative approach to utilizing cationic polyacrylamide (CPAM) synergistically modified with hydrophobic nano silica (SiO 2 ) and 3-(methacryloyloxy)propyltrimethoxy silane (KH570) to enhance oil/water separation efficiency. Comparative evaluation of unmodified CPAM against CPAM-SiO 2 -KH570 composites at varying SiO 2 loadings (10%, 13%, and 16%) revealed significant performance improvements. Unmodified CPAM achieved a peak transmittance of 89% at pH 7 (0.4 g/L), with reduced clarity in acidic and alkaline conditions. In contrast, the nano-modified composites demonstrated superior and more robust flocculation. The 10% SiO 2 composite exhibited excellent clarity (90-94% at pH 7) and the broadest dose tolerance (0.3-0.4 g/L), offering high operational flexibility. The 13% SiO composite achieved the highest and most robust clarity (95-98% at pH 7) over a broad dosage window (0.25-0.4 g/L), maintaining strong performance across varying pH, making it ideal for high-specification polishing. While the 16% SiO 2 composite delivered clarification (∼99%) at lower dosages (0.1-0.2 g/L), it exhibited a narrow optimal window and high pH sensitivity. These enhancements result from the hybrid flocculant’s increased hydrodynamic diameter 16-25 μm vs. ∼7 μm for CPAM and sustained positive charge. Additionally, stronger electrostatic and hydrophobic anchoring via the KH570 alkyl shell, combined with enhanced bridging capability due to rigid silica nodes, leads to more stable flocs. This research demonstrates that hydrophobic nano-modified CPAM offers a highly efficient, fast-kinetics, and structurally robust solution for oilfield wastewater treatment, enabling high separation efficiency with reduced chemical consumption and promoting sustainable water management practices.
危险品化学品经营许可证（带存储）