Simultaneous enhanced ammonia and nitrate removal from secondary effluent in constructed wetlands using a new manganese-containing substrate  

作　　者：Zhihao Xian Jun Yan Jingyi Dai Hao Wu Xin Zhang Wenbo Nie Fucheng Guo Yi Chen 

机构地区：[1]Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment(Ministry of Education),Chongqing University,Chongqing 400044,China [2]College of Environment and Ecology,Chongqing University,Chongqing 400044,China

出　　处：《Frontiers of Environmental Science & Engineering》2024年第4期91-102,共12页环境科学与工程前沿（英文）

基　　金：the Chongqing Science Fund for Distinguished Young Scholars(CSTB2022NSCQ-JQX0023).

摘　　要：Constructed wetlands(CWs)are widely used to treat secondary effluent.However,simultaneously removing ammonia(NH_(4)^(+)-N)and nitrate(NO_(3)^(–)–N)is challenging because of insufficient oxygen and carbon sources.In this study,a novel composite material(MPCM)comprising MnO_(2) and polycaprolactone was developed as a substrate for CWs to enhance the synchronous removal of NH_(4)^(+)–N and NO_(3)^(–)–N.The CWs with a higher MPCM content(H-CW),lower MPCM content(LCW),and controlled CW(C-CW)exhibited average NH_(4)^(+)–N removal efficiencies of 75.69%,70.49%,and 52.40%,respectively.The 15N isotope tracking technique showed that NH_(4)^(+)–N removal was attributed to anaerobic ammonia oxidation mediated by MnO2 reduction(Mnammox),which accounted for 17.16%–27.24%of the NH_(4)^(+)–N removal in the composite material layers(0–20 cm)of the H-CW and L-CW.The richness of ammonia oxidizers in the upper layers(40–50 cm)of the HCW and L-CW further facilitated NH_(4)^(+)–N removal.Moreover,the average total nitrogen(TN)removal efficiencies of the H-CW and L-CW were 1.99 and 1.59 times that of C-CW,respectively,owing to enhanced denitrification by MPCM.Furthermore,N_(2)O emissions were reduced by 81.31%and 70.83%in the H-CW and L-CW,respectively.This study provides an effective approach for improving nitrogen removal and reducing N2O emissions during the treatment of secondary effluent by CWs.

关 键 词：Constructed wetland Nitrogen removal Manganese redox POLYCAPROLACTONE Nitrous oxide 

分 类 号：X70[环境科学与工程—环境工程]