CIESC Journal ›› 2018, Vol. 69 ›› Issue (8): 3509-3516.DOI: 10.11949/j.issn.0438-1157.20171630

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Removal of chromium-containing wastewater by integration treatment of magnetic flocculation and HGMS magnetic-fluid extraction

DU Jiao, SUN Zongying, GUAN Yueping, ZHANG Zhi, LI Tao, XU Guoli, FAN Qingqian   

  1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2017-12-12 Revised:2018-07-03 Online:2018-08-05 Published:2018-08-05
  • Supported by:

    supported by the National Basic Research Program of China (2013CB632602).

磁絮凝法和高梯度磁流体萃取法集成处理含铬废水

杜蛟, 孙宗英, 官月平, 张智, 李涛, 徐郭莉, 范青乾   

  1. 北京科技大学材料科学与工程学院, 北京 100083
  • 通讯作者: 官月平
  • 基金资助:

    国家重点基础研究发展计划项目(2013CB632602)。

Abstract:

The magnetic separation technology was combined with chemical flocculation and solvent extraction method to synthetically provide a new way of treating chromium-containing wastewater by the application of magnetic flocculation and high gradient magnetic separation (HGMS) for magnetic-fluids extraction.Namely magnetic flocculation method was used to treat high concentration chromium-containing electroplating wastewater once, and the optimal magnetic flocculation conditions were obtained by orthogonal test method:pH 8, the dosage of magnetic Fe3O4 particles 4 g, mixing speed 80 r·min-1, the main flocculant PAFC dosage 6 ml, under which can reduce the chromium concentration in the wastewater from 4325.13 mg·L-1 to 29.8·mg·L-1. After magnetic flocculation treatment, the method of high gradient magnetic-fluids extraction was used in secondary processing, the wastewater was pumped and continuously flowed through two series of high gradient magnetic-fluids extraction devices within seven hours, and the highest extraction rate could achieve 99.4%, average extraction rate could achieve 98.97%, under optimal conditions. Furthermore, chromium concentration could be reduced to 0.31 mg·L-1, which met the national emission standard. Under alkaline conditions, the stripping rate of magnetic fluid was more than 90%, and the regenerated magnetic fluid extraction agent can be reused.

Key words: magnetic flocculation, HGMS magnetic-fluid extraction, integration treatment, chromium-containing wastewater

摘要:

将磁分离技术和化学絮凝法、溶剂萃取法相结合,提出磁絮凝法和高梯度磁流体萃取法集成处理高浓度含Cr电镀废水的新工艺。采用磁絮凝法对高浓度含Cr电镀废水进行一次处理,通过正交实验方法获得了最佳磁絮凝条件:pH 8,磁性Fe3O4颗粒用量4 g,搅拌速度80 r·min-1,主絮凝剂PAFC用量6 ml,可使废水中Cr浓度由4325.13 mg·L-1降为29.8 mg·L-1;采用高梯度磁流体萃取法对磁絮凝后废水进行二次处理,将该废水流经两个串联的高梯度磁流体萃取装置,持续动态萃取7 h,在最佳萃取条件下,最高萃取率为99.40%,平均萃取率98.97%,总萃余液Cr浓度由29.8 mg·L-1降为0.31 mg·L-1,低于国家排放标准;碱性条件下磁流体萃取剂反萃率大于90%,再生磁流体萃取剂可重复使用。

关键词: 磁絮凝, 高梯度磁流体萃取, 集成处理, 含铬废水

CLC Number: