Experimental work has been carried out on filtration of polystyrene latex particles through deep fibrous beds aided by electric fields. The use of different fibres allowed their properties to be correlated filtration performance, based on removal of 1 mum diameter particles from an aqueous suspension with a conductivity in the range 5-10 muS cm-1, one order of magnitude lower than natural waters. Correlations were obtained between filtration performance and applied voltage and between relative performance and a factor containing fibre surface charge and wet fibre conductivity.