The cost of filter media contributes a significant proportion of the i
nitial capital outlay in wastewater treatment by biological aerated fi
lters (BAFs). Media characteristics also affect day to day running cos
ts such as those involved in backwashing. To allow an informed choice
relating to filter media and their prospective uses a number of standa
rds have been produced, most recently the British Effluent and Water A
ssociation (BEWA) standard. The aim of this study was to investigate a
number of granular media using the BEWA standard in order to determin
e their suitability for BAFs. All the media samples investigated appea
r suitable for use as BAF media with one in particular having all the
necessary characteristics e.g. low density, high specific surface area
and resistance to attrition. Copyright (C) 1996 IAWQ. Published by El
sevier Science Ltd.