Ecological and Comparative Performance Studies on High-rate Sewage Filter Media

Abstract

Used waters containing high concentrations of organic materials
have proved difficult to treat to suitable standards for discharge to
inland waters ,using conventional biological filtration,
The use of two stage filtration has been shown to produce effluents
of a higher standard than single stage filtration. This investigation
was undertaken to determine the optimum conditions for two stage
filtration where the primary stage employed various types of biological
media designed to accept high organic loadings,
Pilot and laboratory scale filters were designed and constructed
to investigate the mechanisms of two stage filtration, The quality of
effluents obtained from the pilot scale high-rate filters was examined
and their effects on nitrification in laboratory scale secondary
filters employing low organic loadings observed. The ecological
maturation of the high-rate primary filters was monitored.
The study indicated that under the loading conditions considered,
the high-rate filter media developed biological films which could
support carbonaceous oxidation in proportion to the media specific
surface areas, Random packed media developed weights of biological
film in proportion to their specific surface areas, Modular media
supported significantly less film per wit of specific surface area.
The dominant flora and fauna of high-rate filter films were
identified, After two years of operation, -the filters had not fully
matured, ‘
Suitable primary hizh-rate filter effluents could be obtained to
permit full nitrification in laboratory scale nitrifying filters,
Further studies are required to optimise the use of high-rate filtration,

Date of Award	1979
Original language	English