Coagulation prior to membrane filtration is widely accepted as a standard hybrid process
because it allows poorer quality source waters to be used with less fouling. But more must be
understood about the effect of coagulation conditions on the performance of membrane
system, especially in submerged membrane system. The objectives of this research were to
elucidate the relation between coagulation pretreatment and membrane performance and
explore the effect of coagulation pretreatment and microfiltration on GAC post-treatment.
Experiments were conducted in pilot scale using a 500 m3/day plant with submerged
microfilters. Raw water collected from Han River was used as feed water and ploy aluminium
chloride was used as coagulants. Granular activated carbon at EBCT of 15 min was used as
post- treatment of membrane system to control taste and odor in product water. The results
indicate that the coagulation condition had a significant impact on membrane fouling.
Coagulation pretreatment was essential to stabilize transmembrane pressure (TMP) especially
when the turbidity of feed water was high. As more organic matter was removed by
coagulation, membranes fouled less. On the other hand, TMP was not sensitive to feed
turbidity after coagulation and sedimentation. It appears that not only the removal of particles
and organics but also the characteristics of coagulation flocs affect the membrane
performance and pretreatment efficiency. Based on the experimental results, a technique using
fouling index was suggested to control coagulation process. Coagulation was found to
prolong the lifetime of GAC post-treatment by reducing dissolved organic matters up to 60 %. Includes 11 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 420 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 8 |
| Published : | 06/01/2006 |
