Efficient removal of nickel(II) from high salinity wastewater by a novel PAA/ZIF-8/PVDF hybrid ultrafiltration membrane
2018; Elsevier BV; Volume: 143; Linguagem: Inglês
10.1016/j.watres.2018.06.031
ISSN1879-2448
AutoresTing Li, Weiming Zhang, Zhai Shu, Guandao Gao, Jie Ding, Wenbin Zhang, Yang Liu, Xin Zhao, Bingcai Pan, Lu Lv,
Tópico(s)Adsorption and biosorption for pollutant removal
ResumoEnhanced removal of trace toxic metals (ppm level) from high-salinity wastewater is crucial to ensure water safety but still a challenging task. In this study, we fabricated a new hybrid ultrafiltration membrane (PAA/ZIF-8/PVDF) by immobilizing zeolitic imidazolate framework-8 (ZIF-8) particles onto the surface of trimesoyl chloride (TMC)-modified polyvinylidene fluoride (PVDF) membrane under protection of polyacrylic acid (PAA) layer. The resultant PAA/ZIF-8/PVDF membrane exhibited relatively high water flux of 460 L·m-2 h-1 and outstanding nickel ion (Ni(II)) capacity (219.09 mg/g) from a synthetic high-salinity ([Na+] = 15000 mg/L) wastewater. X-ray photoelectron spectroscopic studies revealed that preferable Ni(II) uptake was mainly attributed to the specific interaction between Ni(II) and hydroxyl groups on ZIF-8 frameworks and carboxyl groups in PAA layer as well. Compared to PAA, ZIF-8 could selectively bind Ni(II) with negligible effect exerted by concentrated sodium ion. The filtration study showed that the 12.56-cm2 membrane could effectively treat 5.76 L high-salinity wastewater ([Ni(II)0 = 2 mg/L, [Na+]0 = 15000 mg/L) to conspicuously reduce Ni(II) below the maximum contaminant level of China, 0.1 mg/L. Moreover, the hybrid membrane could be regenerated by HCl-NaCl solution (pH = 5.5) for repeated use under direct current electric field. Generally speaking, the newly developed ZIF-8 hybrid ultrafiltration membrane showed a very promising potential in enhanced removal of toxic metals from high-salinity wastewater treatment.
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