PILOT PLANT SISTEM LUMPUR AKTIF UNTUK PENYISIHAN NITRAT (NO3-N) DAN NITRIT (NO2-N) MELALUI SIMULTANEOUS NITRIFICATION – DENITRIFICATION (SND) DENGAN VARIABEL DO (DISSOLVED OXYGEN)

Abstract

Nitrogen is one of the main nutrients needed in waste water treatment, but if the waste water contains a lot of nitrogen is disposed to the stream may cause eutrophication and other problems. Biological treatment waith activated sludge system Simultaneous Nitrification Denitrification (SND) is able to remove nitrogen optimally because nitrification and denitrification occur in the same tank. In an effort to overcome the problem caused by the high nitric and nitrate concentration, PT. Hartono Istana Teknologi Sayung Demak is planning to change its waste water treatment plant to an activated sludge SND plant. Dissolved Oxygen (DO) use as parameters in this observation because SND require DO control to assure that both nitrification and denitrification occurs in the single tank. The variation of DO concentration is done by change the air flowrate (the number of diffusers) entered in the aeration tank. DO variable used is (0.5 – 1.0) mg/l, (1.0 – 1.5) mg/l, (1.5 – 2.0) mg/l, and (2.0 – 2.5) mg/l. The effect of the DO concentration to the activated sludge Simultaneous Nitrification Denitrification (SND) removal is illustrative by the removal efficiency of NO2-N and NO3-N. The most efficient of the NO2-N and NO3-N removal is on the (0.5 – 1.0) mg/l , which is; 98.39% for the NO2-N removal efficiency, and 97.47% for the NO3-N removal efficiency. The efficiency of the removal of NO2-N and NO3-N achieve the design criterion, so this activated sludge treatment with SND method did increase the effluent quality compared to the original treatment. The effluent of this treatment has fulfilled the standard quality of the waste water disposal. The conclusion by the analysis based on this experiment shows by using the activated sludge system with SND method is able to finished the problem at PT. Hartono Istana Teknologi Sayung Demak waste water to make the effluent with low NO2-N and NO3-N concentration.