An integrated biological-electrocatalytic process for highly-efficient treatment of coking wastewater. (November 2021)

• Record Type: Journal Article
• Authors: Wu, Zhen-Yu; Zhu, Wei-Ping; Liu, Yang; Zhou, Lu-Lu; Liu, Peng-Xi; Xu, Juan
• Is Part Of: Bioresource technology. Volume 339(2021)
• Publication Date: 2021-11
• Subjects: Coking wastewater -- Biological-electrocatalytic system -- Three-dimensional biofilm electrode reactor -- Biological aerated filter; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.125584
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: A novel biological-electrocatalytic system is developed to treat coking wastewater. 3DERs decompose NH4 + -N, NO3 – -N and COD by electrochemical redox reactions. BAFs convert NH4 + -N to NO3 – -N and remove partial COD. 3DBER mainly eliminates NO3 – -N by bio-electrochemical denitrification. The toxicity of coking wastewater is significantly reduced. Abstract: Coking wastewater is typically refractory, mainly due to its biological toxicity and complex composition. In this study, a novel integrated biological-electrocatalytic process consisting of two three-dimensional electrochemical reactors (3DERs), two biological aerated filters (BAFs), and a three-dimensional biofilm electrode reactor (3DBER) is developed for the advanced treatment of coking wastewater. 73.21% of chemical oxygen demand (COD), 38.02% of ammonium nitrogen (NH4 + -N) and 91.46% of nitrate nitrogen (NO3 – -N) are removed by 3DERs. BAFs mainly convert NH4 + -N to NO3 – -N through microbial nitrification. The 3DBER removes the residual NO3 – -N by bio-electrochemical denitrification. The integrated system can eliminate 74.72–83.27% of COD, 99.38–99.74% of NH4 + -N, and 69.64–99.83% of total nitrogen from coking wastewater during the continuous operation, as well as significantly reducing the toxicity of the wastewater. The superiorities of the integrated 3DERs/BAFs/3DBER system recommend the application of such biological-electrocatalytic technology in the treatment of highly toxic wastewater.