Study on Mechanism of Simultaneous Nitrification and Denitrification with Four Kinds of Fillers in Simulated Situ Bioremediation for Taihu Lake

Four kinds of different fillers are selected to investigate effects of simultaneous nitrification and denitrification by biofilm process in simulated situ bioremediation in laboratory scale for Taihu Lake. Water temperature and filling rate are both investigated to optimize nitrogen removal effects at the water temperature of 30 °C, 20 °C, 10 °C and the filling rate of 30%, 50%, 70%, respectively. Under the conditions of 30 °C water temperature and 70% filling rate, nitrogen removal effects of filler 1# is best, nitrogen removal efficiency of simultaneous nitrification and denitrification (SND) is 95.44%, nitrogen removal effects of filler 3# is worst, its SND removal efficiency is 79.30%. Moreover, the surface of filler 1# and filler 2# is rough enough to have a hydrophilia for the growth of microorganisms, compare with filler 3# and filler 4#. Thus, the filler 1# and filler 2# could remove more TN and protect polluted surface water, water quality is promoted from class V to class III.