Study on runoff nitrogen removal efficiency of biochar amended pyrite substrate bioretention facility
Pyrite bioretention systems,as an emerging stormwater treatment facility with sim-ultaneous nitrogen and phosphorus removal,have a wide range of potential applications.To ad-dress the problem of low nitrogen removal performance of pyrite bioretention systems under high nitrogen loading of runoff,a biochar-modified pyrite bioretention system was developed,and the nitrogen removal performance of the biochar-modified bioretention system with autotrophic denitri-fication of pyrite on simulated stormwater runoff,as well as the removal of COD and TP,was in-vestigated,and the surface of the reacted pyrite in the system was characterized by SEM.The re-sults showed that the bioretention system with mixed substrate of biochar and pyrite could achieve more efficient denitrification and nitrogen removal,with an average removal rate of 71.2％for NOx--N and 75.6％for TN,and the system had low COD demand and was able to carry out deni-trification efficiently when faced with a low C/N ratio of rainfall by the electron shuttling and stor-age battery mechanism of biochar.At the same time,the water-holding capacity of biochar can ef-fectively reduce the degree of oxidation of pyrite,thereby extending the life of the bioretention sys-tem.
NETL
NSTL
万方数据
