Ingeniero De Minas

Desalination 223 (2008) 349–360

Heavy metal-contaminated groundwater treatment by a novel nanofiber membrane
Yimin Sanga*, Fasheng Lib, Qingbao Gub, Cunzhen Lianga, Jiaqing Chena
Department of Environmental Engineering, Beijing Institute of Petrochemical Technology, 19 Qingyuan North Road, Daxing District, Beijing 102617, China Tel. +86 13671116309; Fax +86 1081292291; email:soundym@vip.sohu.com b Department of Soil Pollution Control, Chinese Research Academy of Environmental Science, Beijing 100012, China
Received 18 December 2006; accepted 3 January 2007
a

Abstract The morphology, interspace and surface properties of a novel nanofiber membrane are characterized by scanning electron microscopy (SEM), pore percent and contact angle. The membrane, named M-1, is prepared fromchloridized polyvinyl chloride by high-voltage electrospinning process. The removals of divalent metal cations including Cu2+, Pb2+ and Cd2+ from the simulated groundwater by M-1 have been investigated. To obtain the best heavy metal removal, several experimental methods using M-1 have been presented, including static adsorption, direct filtration, soil-addition filtration, diatomite-additionfiltration and micellar enhanced filtration (MEF). Specially, MEF experiments are performed as a function of SDBS concentration and applied membrane layers. From static adsorption experiments, maximum uptakes of Cu2+, Cd2+, Pb2+ and their adsorption equilibrium time have been obtained respectively in the simulated groundwater. Dynamic filtration experiments indicate that the best experimental methodfor M-1 to remove heavy metal cations is MEF whose optimal experimental conditions are 10-layer filtration and sodium dodecyl benzene sulfonate (SDBS) concentration of 5 mmol/L. The experimental results show that the rejections of copper in the simulated groundwater by MEF using M-1 can reach more than 73%; the rejections of lead more than 82%; and the rejections of cadmium more than 91%. It isindicated that MEF method using M-1 can be used for the treatment of the groundwater containing Cu2+, Pb2+ and Cd2+ with high efficiency. Keywords: Nanofiber membrane; Heavy metal removal; Groundwater; Adsorption; Micellar-enhanced filtration

*Corresponding author. Presented at the conference on Desalination and the Environment. Sponsored by the European Desalination Society and Center forResearch and Technology Hellas (CERTH), Sani Resort, Halkidiki, Greece, April 22–25, 2007.
0011-9164/06/$– See front matter © 2008 Published by Elsevier B.V. doi:10.1016/j.desal.2007.01.208

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Y. Sang et al. / Desalination 223 (2008) 349–360

1. Introduction Groundwater pollution, often due to contaminant seepage from the disposal sites, is a big problem in many countries [1]. Industriessuch as plating, ceramics, glass, mining and battery manufacturing are considered the main sources of heavy metals in local water streams, which will cause the contamination of groundwater with heavy metals. Besides, heavy metals which are commonly found in high concentrations in landfill leachate are also a potential source of pollution for groundwater [2]. In peri-urban areas of developingcountries, e.g. China, sewage irrigation may affect heavy metal content in groundwater in the long term. The elevated level of heavy metals in the groundwater poses a substantial risk to local resource users and to the natural environment potentially. In China, the removal of heavy metals from groundwater has more and more captured the interest of the public and government. Because of theirintrinsically persistent nature, when heavy metal ions (Cu2+, Cd2+, Pb2+, etc.) are discharged or transported into the environment, they may undergo transformations and can have a large environmental, public health and economic impact [3,4]. Current methods available for removing heavy metals from groundwater include coagulation, flocculation, precipitation–filtration, ion-exchange, reverse osmosis,...