[Nitrogen uptake and denitrification study on the joint treatment of aquatic vegetation and immobilized nitrogen cycling bacteria in Taihu Lake].

Undisturbed sediment cores were collected from Meiliang Bay, Taihu Lake. Immobilized nitrogen cycling bacteria (INCB), Elodea nuttallii were added to four groups of restoration incubation chambers respectively to explore the nitrogen removal mechanism in different restoration treatments. uN tracer and isotope pairing technique were used to determine the rates of plant uptake and denitrification in different treatments. The results showed that denitrification rates were significantly different among the treatments, while cores with addition of both INCB and Elodea nuttallii achieved the highest denitrification rate of 99.35 μmol · (m2 · h)( -1) and plant uptake rate of 36.55 μg · (m2 · h) -1. Elodea nuttallii in the cores could assimilate nitrate itself and enhance coupled nitrification- denitrification. Compared with plant uptake, denitrification was the main pathway of nitrogen removal. The results also showed that the combination of Elodea nuttallii and INCB could promote benthic nitrogen removal and purification of water body.