Highly efficient removal of ammonia nitrogen from wastewater by dielectrophoresis-enhanced adsorption

Dongyang Liu; Chenyang Cui; Yanhong Wu; Huiying Chen; Junfeng Geng; Jianxin Xia

doi:10.7717/peerj.5001

Highly efficient removal of ammonia nitrogen from wastewater by dielectrophoresis-enhanced adsorption

PeerJ. 2018 Jun 15:6:e5001. doi: 10.7717/peerj.5001. eCollection 2018.

Authors

Dongyang Liu¹, Chenyang Cui¹, Yanhong Wu¹, Huiying Chen¹, Junfeng Geng², Jianxin Xia¹

Affiliations

¹ College of Life and Environmental Science, Minzu University of China, Beijing, China.
² Institute for Materials Research and Innovation, Institute for Renewable Energy and Environmental Technologies, University of Bolton, Bolton, UK.

Abstract

A new approach, based on dielectrophoresis (DEP), was developed in this work to enhance traditional adsorption for the removal of ammonia nitrogen (NH₃-N) from wastewater. The factors that affected the removal efficiency were systematically investigated, which allowed us to determine optimal operation parameters. With this new method we found that the removal efficiency was significantly improved from 66.7% by adsorption only to 95% by adsorption-DEP using titanium metal mesh as electrodes of the DEP and zeolite as the absorbent material. In addition, the dosage of the absorbent/zeolite and the processing time needed for the removal were greatly reduced after the introduction of DEP into the process. In addition, a very low discharge concentration (C, 1.5 mg/L) of NH₃-N was achieved by the new method, which well met the discharge criterion of C < 8 mg/L (the emission standard of pollutants for rare earth industry in China).

Keywords: Adsorption; Ammonia nitrogen; Dielectrophoresis; Wastewater; Zeolite.

Grants and funding

This work was supported by National Major Science and Technology Program for Water Pollution Control and Treatment (No. 2017ZX07101-002), the Fundamental Research Funds for the Central Universities (2016SHXY06) and National Natural Science Foundation of China (No. 51609271). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.