The combination of lime softening, chlorination, clarification and filtration
have long been used as a treatment process in beverage plants
because it provides consistent water quality. However, these
processes require a very large plant area, generate a large volume of
sludge that causes disposal problems, resulting in creating more problems than
the benefits they offer. Chlorination produces trihalomethanes
(THMs) and other byproducts which are detrimental to health and
gives a taste to the final products. Using submerged spiral
wound ultrafiltration membranes integrated with lime softening
may replace the conventional lime softening, clarification and
filtration processes.
This research was conducted to demonstrate the feasibility of
integrating immersed ultrafiltration (UF) membrane with lime
softening. A pilot unit consisting of lime reactor and UF system
treating municipal water supply was operated for a period of 1800
hours, at various pH levels ranging from 7.3 to 11.2, and at membrane flux
rates of 15, 30 and 45 gfd. The filtrate from the pilot unit
achieved alkalinity reduction to 20 to 30 mg/L preferred by
carbonated soft drinks bottlers, with lime dosage close to the
calculated value. The filtrate turbidity during the test was
consistently 0.05 NTU. The TMP values obtained during the test
ranged from 0.1 to 2.5 psi, while the permeability values ranged
from 18.19 to 29.6 gfd/psi. The increase in flux resulted in a
corresponding increase in TMP, and the increase in operating pH
increases the rate of TMP. Permeability decreases with increasing
operating pH. The total organic carbon (TOC) reduction ranges from 2.6 % to 15.8% with
increasing operating pH. No scaling of the UF membranes was observed
during the test. A thirty day UF membrane cleaning interval was
predicted. The results from this study can be used as the basis of
designing and operating a full scale Integrated Lime Softening UF
Treatment Plant. Includes 12 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 470 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 03/01/2007 |
