Purification of pickling wastewater from the steel industry using membrane filters: Performance and membrane fouling |
Jinfeng Zhang1,2†, Guanyi Chen1,3, Yanning Ma2, Miao Xu2, Songyan Qin4, Xiaoliang Liu2, Haijun Feng2, and Lian Hou1 |
1School of Environmental Science and Technology, Tianjin University, Tianjin 300072, China 2Tianjin Academy of Environmental Sciences, Tianjin 300191, China 3School of Science, Tibet University, No. 36 Jiangsu Street, Lhasa 850012, Tibet Autonomous Region, China 4Tianjin University of Technology, Tianjin 300384, China |
Corresponding Author:
Jinfeng Zhang ,Tel: +86-022-87671613, Fax: +86-022-87671613 , Email: zjf644@163.com |
Received: August 27, 2020; Accepted: December 24, 2020. |
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ABSTRACT |
A new technique for treating pickling wastewater discharged from the steel industry using membrane filters was developed and membrane fouling was characterized in a full scale membrane filter. The morphological and chemical properties were examined through scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) etc. The results showed that inorganic elements such as phosphates, chlorides, and sulfates were severely blocked in membrane surfaces and pores. The porosity, permeability, hydrophilic contact angle, and surface charge capacity of fouled membranes were all lower than those of new membranes, while the optimal neutralization reaction pH region for fouled membranes shifted and narrowed. Charge neutralization is a critical reason to membrane fouling. By increasing the Zeta potential of the pickling wastewater, the membrane fouling could be controlled. This method is proven to effectively improve the separation property of precipitates after pickling wastewater was neutralized. Moreover, Neutralization helped to reduce the unit number of treatment processes. This investigation could assist in obtaining a better understanding of the fouling properties and behavior in the full-scale membrane filters in the pickling wastewater treatment. |
Keywords:
Hydrophilic contact angle | Membrane filter | Membrane fouling | Pickling wastewater | Porosity | Zeta potential |
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