Enhanced Removal of Cr (VI) by PEI/nFe3O4 Ultrafiltration Membranes Using Peristaltic Pump-Driven Dynamic Adsorption
Hui-Lai Zhang
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Ming-Chao Zhu
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Hao-Qiang Fu
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Yong-Ze Lu
School of Energy and Environment, Southeast University, Nanjing 210096, China, Key Laboratory of Water Pollution Control and Ecological Restoration of Xizang, National Ethnic Affairs Commission, Xizang Minzu University, Xianyang 712082, China and Information Engineer College, Xizang Minzu University, Xianyang 712082, China.
Shou-Wen Chen
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Zhao-Xia Hu
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Na Li *
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
*Author to whom correspondence should be addressed.
Abstract
In this study, Fe3O4 nanoparticles (nFe3O4) were loaded onto polyvinylidene fluoride ultrafiltration membranes and capped with polyethyleneimine in order to form PEI/nFe3O4 ultrafiltration membranes. We used a peristaltic pump as a driver for dynamic adsorption, and the PEI/nFe3O4 ultrafiltration membrane had a good ability to remove hexavalent chromium (Cr(VI)) from wastewater. The full permeate volume of the PEI/nFe3O4 ultrafiltration membrane was maximized at pH 3. Meanwhile, the removal of Cr(VI) from the wastewater reached 98% and reduced to trivalent chromium (Cr(III)). When the initial concentration of Cr(VI) increased, the active sites on the membrane would be filled and the removal efficiency of Cr(VI) would decrease. Meanwhile, the coexisting ions affect the removal efficiency of Cr(VI), and PO43- has a strong negative effect on the removal efficiency. PEI/nFe3O4 ultrafiltration membrane is an effective combination of multifunctional nanomagnetic materials and membrane materials, which can effectively remove hexavalent chromium from wastewater. The study provides a basis for future applications in the environmental remediation of low-concentration chromium-containing wastewater.
Keywords: Nano Fe3O4 particles, hexavalent chromium, adsorption membrane, heavy metal