Role of porous polymer carriers and iron-carbon bioreactor combined micro-electrolysis and biological denitrification in efficient removal of nitrate from wastewater under low carbon to nitrogen ratio

Jian Liu; Junfeng Su; Amjad Ali; Zhao Wang; Changlun Chen; Liang Xu

doi:10.1016/j.biortech.2020.124447

Role of porous polymer carriers and iron-carbon bioreactor combined micro-electrolysis and biological denitrification in efficient removal of nitrate from wastewater under low carbon to nitrogen ratio

Bioresour Technol. 2021 Feb:321:124447. doi: 10.1016/j.biortech.2020.124447. Epub 2020 Dec 3.

Authors

Jian Liu¹, Junfeng Su², Amjad Ali³, Zhao Wang³, Changlun Chen³, Liang Xu³

Affiliations

¹ Xi'an University of Architecture and Technology University of South Australia An De College, Xi'an 710055, China.
² Xi'an University of Architecture and Technology University of South Australia An De College, Xi'an 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: sjf1977518@sina.com.
³ School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.

PMID: 33302007
DOI: 10.1016/j.biortech.2020.124447

Abstract

In the current research, a novel bioreactor composed of porous polymer carriers and iron-carbon (PPC@FeC) was established through bacterial immobilized technology. The influence of key factors was studied on the nitrate removal performance of the PPC@FeC bioreactor. The experimental results showed that the highest removal rate of nitrate (7.33 mg L^-1 h^-1) can be obtained with short hydraulic retention times (HRT = 2.0 h) and low carbon-to-nitrogen ratio (C/N = 2.0). The results of high-throughput sequencing revealed that Zoogloea sp. L2 was the dominant strain in bioreactor responsible for nitrate removal. Moreover, the SEM and XRD analyses elucidated that Fe₂O₃ was the final product produced by the interaction of FeC and strain L2. These findings showed that the PPC@FeC bioreactor successfully combined micro-electrolysis and biological denitrification, which exhibited great potential in removing nitrate effectively from wastewater under low C/N ratio and short HRT conditions.

Keywords: Denitrification; Micro-electrolysis; Nitrate removal; PPC@FeC bioreactor.

MeSH terms

Bioreactors
Carbon
Denitrification
Electrolysis
Iron
Nitrates*
Nitrogen
Polymers
Porosity
Wastewater*

Substances

Nitrates
Polymers
Waste Water
Carbon
Iron
Nitrogen