Open AccessSimultaneous Removal of Nitrogen and Refractory Organics from a Biologically Treated Leachate by Pulse Electrochemical Oxidation in a Multi-channel Flow Reactor
Author(s) -
Zhanghao Jiang,
Zhiliang Cheng,
Chaoqun Yan,
Xuan Zhang,
Yijuan Tian,
Xianming Zhang,
Xuejun Quan
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c03567
Subject(s) - effluent , chemical oxygen demand , electrochemistry , chemistry , leachate , anode , wastewater , nitrogen , pulp and paper industry , environmental engineering , electrode , environmental chemistry , environmental science , organic chemistry , engineering
Electrochemical oxidation (EO) is often used in the advanced treatment of refractory wastewater. However, in a conventional EO process of direct-current (DC) power supply, oxide layers often form on the anodes, which not only hinder the oxidation reaction on them but also cause higher energy consumption. In this paper, a biologically treated leachate (BTL) of municipal solid waste (MSW) was comparably treated by EO with DC (DC-EO), monopulse (MP-EO), and double pulse (DP-EO) power source models in a home-made multi-channel flow reactor. The effects of process parameters of current density ( I A ), superficial liquid velocity ( U L ), pulse frequency ( f P ), duty ratio ( R D ), and so forth on the removal efficiency of chemical oxygen demand (COD) (RE COD ), total organic carbon (TOC) (RE TOC ), and total nitrogen (TN) (RE TN ) were investigated simultaneously. Average energy consumption () and organic composition of the treated effluent of DC-EO and MP-EO were also compared comprehensively, and a new mechanism of MP-EO has been proposed accordingly. Under optimal conditions, 2 L of BTL was treated by MP-EO for 180 min, and the RE COD , RE TOC , and RE TN could reach as high as 80, 30, and 80%, respectively. Compared with DC-EO, the of MP-EO is reduced by 69.27%. Besides, the kinds of organic matter in the treated effluent of MP-EO are reduced from 53 in the BTL to 11, which is much less than in the DC-EO process of 29 kinds. Therefore, the MP-EO process exhibits excellent removal performance of organics and TN and economic prospects in the treatment of refractory organic wastewater.