Carbon slow-release and enhanced nitrogen removal performance of plant residue-based composite filler and ecological mechanisms in constructed wetland application

Zhaoyang Li; Tianyin Huang; Wei Wu; Xiaoyi Xu; Bingdang Wu; Jinlong Zhuang; Jingjing Yang; Haochen Shi; Yang Zhang; Bin Wang

doi:10.1016/j.biortech.2024.130795

Carbon slow-release and enhanced nitrogen removal performance of plant residue-based composite filler and ecological mechanisms in constructed wetland application

Bioresour Technol. 2024 May 4:402:130795. doi: 10.1016/j.biortech.2024.130795. Online ahead of print.

Authors

Zhaoyang Li¹, Tianyin Huang², Wei Wu², Xiaoyi Xu³, Bingdang Wu², Jinlong Zhuang¹, Jingjing Yang², Haochen Shi¹, Yang Zhang¹, Bin Wang⁴

Affiliations

¹ College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
² College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Key Laboratory of Suzhou Sponge City Technology, Suzhou 215009, China.
³ College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Key Laboratory of Suzhou Sponge City Technology, Suzhou 215009, China. Electronic address: xuxiaoyiskd@usts.edu.cn.
⁴ College of Civil Engineering, Guizhou University, Guiyang, 550025, China.

PMID: 38705213
DOI: 10.1016/j.biortech.2024.130795

Abstract

Stable carbon release and coupled microbial efficacy of external carbon source solid fillers are the keys to enhanced nitrogen removal in constructed wetlands. The constructed wetland plant residue Acorus calamus was cross-linked with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) to create composite solid carbon source fillers (Ac-BDPs). The study demonstrated the slow release of carbon sources from Ac-BDPs with 35.27 mg/g under an average release rate of 0.88 mg/(g·d). Excellent denitrification was also observed in constructed wetlands with Ac-BDPs. Moreover, the average removal rate of nitrate nitrogen (NO₃^--N) was increased by 1.94 and 3.85 times of the blank groups under initial NO₃^--N inputs of 5 and 15 mg/L, respectively. Furthermore, the relatively high abundances of nap, narG, nirKS, norB, qnorZ and nosZ guaranteed efficient denitrification performance in constructed wetlands with Ac-BDPs. The study introduced a reliable technique for biological nitrogen removal by using composite carbon source fillers in constructed wetlands.

Keywords: Composite carbon source filler; Constructed wetland; Denitrification; Functional gene.