This study was to investigate the effects of dumping nightsoil, septage, and leachate to the activated sludge process receiving a mixture of sewage and industrial wastewater on its treatment performance.
For the mixture of sewage and industrial waste...
This study was to investigate the effects of dumping nightsoil, septage, and leachate to the activated sludge process receiving a mixture of sewage and industrial wastewater on its treatment performance.
For the mixture of sewage and industrial wastewater, the overall removal efficiencies of BOD, COD and SS were 87.6%, 74.5% and 94.0% respectively. When the nightsoil and septage were dumped into the plant, the scum and foaming problems occurred at each stage of treatment unit. Direct dumping of the septage also induced the DO deficiencies in the aeration tanks, which resulted in a deflocculation problem in the secondary clarifiers. It may be favorite to pretreat it at the nightsoil treatment plant. When the leachate was dumped into the plant, the effluent qualities were highly fluctuating probably due to the presence of the toxic and inhibitory substances in it. It might be necessary to pretreat the raw leachate at the landfill site prior to dumping it into the plant.