This work involved the treatment of industrial wastewater from a nylon
-carpet printing plant in Northern Ireland which currently receives no
treatment and is discharged straight to sea. As nylon is particularly
difficult to dye, acid dyes are required for successful colouration,
but they cause major problems with the plant's effluent disposal. Gran
ular activated carbon Filtrasorb 400 was used to treat this effluent i
n a fixed-bed column system. Breakthrough curves from the fixed-bed co
lumn were shallow, even at low flow rates, which indicated a large mas
s transfer zone and inefficient use of adsorbent. Decrease in adsorben
t particle size and decrease in linear flow rate produced a better bed
performance. The bed depth service time (BDST) model proved effective
for comparison of column variables, with calculated BDST constants pr
oviding a useful indication of bed performance. The BDST model also ga
ve good approximation in predicting a bed performance using the relati
onships postulated by Hutchins (1973). (C) 1997 Elsevier Science Ltd.