A dynamic model was developed to describe the competitive adsorption of
trace organic compounds by powdered activated carbon (PAC) in a PAC/membrane
filtration system. Two major competitive mechanisms caused by natural organic matter (NOM), direct
competition for sites and pore blockage were considered. The model accurately predicted
atrazine removal in the presence of 1,4-dichlorobenzene (p-DCB) and poly(styrene
sulfonate) (PSS), which represented the strongly competing and the pore blocking NOM
fractions, respectively. The model was applied to investigate the effects of important
design and operating parameters such as the length of membrane cleaning interval,
manner of membrane cleaning (backwash or hydraulic flushing), PAC type, dose, and
dosing scenarios on the removal of trace organic compounds. Atrazine removal was
found to be affected by the membrane cleaning interval (MCI) more than by the hydraulic
retention time (HRT). It was also found that a long MCI was not necessarily beneficial
for the adsorption of trace organic compounds when low PAC doses were used. The
optimal membrane backwash interval for trace organic compound removal should be
determined based on the NOM characteristics of the influent water, the PAC dose and the
backwash or hydraulic flushing water quality. The type of adsorbent was also very
important. It should be selected based on the NOM characteristics of the influent water. Includes 10 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 310 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 18 |
| Published : | 03/05/2003 |
