Leachate treatment by a pilot scale ceramic membrane bioreactor

The experimental research presented here was carried out for over one year and proved the reliability of complete leachate nitrification in a pilot-scale pure-oxygen MBR (V = 500 L) at a maximum rate of 0.6 kgTKN (kgTSS d)-1 at 25 ± 1°C. Leachate came from a MSW landfill that was closed in 1994; it was treated in a full scale anaerobic rector before entering the pilot-scale MBR. The ceramic membrane was a MEMBRALOX® P19-40 tubular zirconic membrane, 50 nm pore size diameter. Chemical cleaning was performed very seldom, since one of the objectives of the experimentation was checking membrane robustness against clogging in the long run at increasing total solid concentration. For complete nitrogen removal, post-denitrification with a moving bed biofilm reactor (MBBR) was also tested in the experimental programme, as the COD/TKN ratio of the leachate was around 4 – 4.5. A pre-denitrification stage could also be considered for future research or full scale application, allowing partial removal of nitrate.