As nitrogen removal requires anaerobic conditions for denitrification,which facilitates the production of methane(CH_(4)),a potent greenhouse gas,it is a challenge to achieve nitrogen removal with minimal CH_(4) emiss...As nitrogen removal requires anaerobic conditions for denitrification,which facilitates the production of methane(CH_(4)),a potent greenhouse gas,it is a challenge to achieve nitrogen removal with minimal CH_(4) emissions in constructed wetlands(CWs).This study proposed a solution for mitigating CH_(4) emissions while achieving nitrogen removal using porous fillers in CWs.We found that active denitrification occurred in the interior pores of these fillers in an oxygen-rich environment.The microbial analysis indicated that the internal pores of porous fillers created anaerobic habitats for denitrifiers as they had a higher nosZ/amoA ratio than on the surface.The anaerobic decomposition of organic matter was inhibited,yielding significantly lower CH_(4)/CO_(2) ratios(<1.0×10^(-5))than those of traditional CWs(0.07).The methanogen proliferation and CH_(4) production efficiency also remained at low levels(<1.1×10^(-3) and 0.045%,respectively),which was significantly lower than in traditional CWs(2.3×10^(6) and 38%,respectively).Overall,this study proposed a strategy for mitigating the greenhouse effect of carbon emissions from CWs in the future.展开更多
基金supported by National Natural Science Foundation of China(No.42422605,42277060,42477073)National Key Research and Development Program of China(No.2024YFC3214500)Natural Science Foundation of Jiangsu Province(BK20240142).
文摘As nitrogen removal requires anaerobic conditions for denitrification,which facilitates the production of methane(CH_(4)),a potent greenhouse gas,it is a challenge to achieve nitrogen removal with minimal CH_(4) emissions in constructed wetlands(CWs).This study proposed a solution for mitigating CH_(4) emissions while achieving nitrogen removal using porous fillers in CWs.We found that active denitrification occurred in the interior pores of these fillers in an oxygen-rich environment.The microbial analysis indicated that the internal pores of porous fillers created anaerobic habitats for denitrifiers as they had a higher nosZ/amoA ratio than on the surface.The anaerobic decomposition of organic matter was inhibited,yielding significantly lower CH_(4)/CO_(2) ratios(<1.0×10^(-5))than those of traditional CWs(0.07).The methanogen proliferation and CH_(4) production efficiency also remained at low levels(<1.1×10^(-3) and 0.045%,respectively),which was significantly lower than in traditional CWs(2.3×10^(6) and 38%,respectively).Overall,this study proposed a strategy for mitigating the greenhouse effect of carbon emissions from CWs in the future.
