Biological treatment of highly concentrated wastewater
from environmentally friendly toilet facilities in a rolling stock

Summary

Russian Railways has been operating over 8,200 passenger carriages equipped with environmentally friendly vacuum-type toilet facilities. The object of the study was wastewater from environmentally friendly toilet facilities of a rolling stock in the repair and servicing shop of the Moscow Railways. The pilot test objective was developing a process flow scheme of wastewater treatment based on aerobic biological treatment in bioreactors with HPDE PP plastic media to achieve the standard effluent quality for discharge into the municipal sewer system. The studies were carried out in three series-connected periodic pilot bioreactors. The pollution indicators in the wastewater at the inlet of the pilot unit were: BOD5 2230 mg/dm³, COD 4530 mg/dm³, ammonium ion 1740 mg/dm³. The achieved purification efficiency of the pilot unit as for BOD5 was 91%, for COD 91%. The obtained data allow to recommend implementing the proposed treatment process flow scheme in a full-scale flow through mode, and conducting further studies of nitri-denitrification with account of using disinfectants for the effluent of environmentally friendly toilet facilities of the rolling stock.

Key words

biological treatment , bioreactor , high concentrated wastewater , environmentally friendly vacuum-type toilet facilities , rolling stock