Purification of pickling wastewater from the steel industry using membrane filters: Performance and membrane fouling

Zhang, Jinfeng; Chen, Guanyi; Ma, Yanning; Xu, Miao; Qin, Songyan; Liu, Xiaoliang; Feng, Haijun; Hou, Lian

doi:.0..

DOI: https://doi.org/10.4491/eer.2020.486

Purification of pickling wastewater from the steel industry using membrane filters: Performance and membrane fouling

Jinfeng Zhang^1,2^†, Guanyi Chen^1,3, 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.

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.