Modified solid carbon sources with nitrate adsorption capability combined with nZVI improve the denitrification performance of constructed wetlands

Yufeng Zhao; Xinshan Song; Xin Cao; Yuhui Wang; Zhimiao Zhao; Zhihao Si; Shihong Yuan

doi:10.1016/j.biortech.2019.122189

Modified solid carbon sources with nitrate adsorption capability combined with nZVI improve the denitrification performance of constructed wetlands

Bioresour Technol. 2019 Dec:294:122189. doi: 10.1016/j.biortech.2019.122189. Epub 2019 Sep 24.

Authors

Yufeng Zhao¹, Xinshan Song², Xin Cao¹, Yuhui Wang¹, Zhimiao Zhao³, Zhihao Si¹, Shihong Yuan¹

Affiliations

¹ State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
² State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China. Electronic address: newmountain@dhu.edu.cn.
³ College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, PR China; Engineering Research Center for Water Environment Ecology in Shanghai, Shanghai 201306, PR China.

PMID: 31569043
DOI: 10.1016/j.biortech.2019.122189

Abstract

In this study, various modified agricultural wastes (modified canna leaves (MCL), modified rice straw (MRS) and modified peanut shells (MPS)) as solid carbon sources (SCSs) were used to remove nitrate in constructed wetlands (CWs). Then, modified SCSs combined with nZVI (SCSN) as co-electrons further enhanced both heterotrophic denitrification (HD) and autotrophic denitrification (AD) performance of CWs. The results showed that NO₃^--N removal efficiencies in CWs with SCSNs (75.3-91.1%) and in CWs with SCSs (63.3-65.5%) were significantly higher than that in CK-CW (47.0%). The presence of SCSs reduced the accumulation of NO₂^--N in CWs. Compared to the addition of SCSs, the addition of SCSNs decreased the effluent COD concentration in CWs, avoiding secondary pollution. In addition, the solid-phase denitrifiers Silanimonas and Thauera were enriched in MPS-CW. Thermomonas, an autotrophic denitrifying bacteria (ADB), and Azospira, a nitrate-reducing Fe (II) oxidation bacteria (NRFOB), exhibited high relative abundance in MPN-CW.

Keywords: CWs; Denitrification performance; Microbial diversity; Solid carbon source; nZVI.

MeSH terms

Adsorption
Carbon
Denitrification*
Nitrates
Nitrogen
Wetlands*

Substances

Nitrates
Carbon
Nitrogen