Page 228 - ro membanes

9.7 OVERVIEW OF MEMBRANE PRODUCTS USED FOR SALINE WATER PRETREATMENT 211 TABLE 9.6 Memcor (Evoqua) Membrane Pretreatment Systems
Parameter
Membrane elements (modules) Module configuration
Number of modules per unit (maximum)
Module length
Module diameter
Membrane area
Fiber inner diameter, mm
Fiber outer diameter, mm
Maximum trans-membrane pressure
pH operating range
Weight per module
Suitable for pump-through configuration
Submerged CS-10V
S10 V Vertical 900
1.19 m (47-in.) 130 mm (5.2-in.) 27.9 m2(300 ft2) 0.5
0.8
1.2 bar (17 psi)
1.0e10.0
6.5 kg (14 lbs) No
Pressurized CP-L10 V
L10 V Vertical 960
1.19 m (47-in.) 150 mm (5.9-in.) 55 m2(252 ft2) 0.25
0.5
1.5 bar (21 psi)
1.0e13.0
6.5 kg (14 lbs) Yes
Pressurized CP-L20 V
L20 V Vertical 960
1.80 m (71-in.) 120 mm (4.7-in.) 38.1 m2(410 ft2) 0.25
0.5
1.5 bar (21 psi)
1.0e13.0
9 kg (20 lbs) Yes
and their fibers have pore sizes of 0.04 mm. Memcor membranes are classified as UF type and their pore size is adequately small to remove up to 3 logs (99.9%) of viruses. Table 9.6 pro- vides a summary of the key performance parameters of the Memcor membrane elements that have found application for seawater pretreatment. Besides the UF membranes listed in Table 9.6, Memcor offers a number of other UF elements.
Both submerged and pressurized Memcor (Evoqua) units are designed for combination of air and water backwash. Submerged systems have slightly higher backwash volume (reject flow), of 7%e8% compared to pressure-driven systems, which generate backwash volume of 4%e5% of the total intake flow.
The Southern Seawater Desalination Plant in Perth, Australia, with total fresh water pro- duction capacity of 300,000 m3/day (80 MGD) uses pressure-driven Memcor CP 960 mem- brane racks (see third column of Table 9.6). These racks have 912 modules each. The desalination plant consists of two 150,000 m3/day (40 MGD) plants, which share common intake and outfall. Each plant has two sets of four duty and one standby racks (e.g., a total of 20 CP 960 racks for the entire plant). The membranes are designed for a flux of 65 lmh (38 gfd) and produce filtered water of SDI15 lower than 3 for over 95% of the time.
The 300,000 m3/day (80 MGD) Adelaide desalination plant in Australia uses submerged Memcor CS membrane pretreatment system and consists of two 150,000 m3/day (40 MGD) plants with common intake and outfall. The pretreatment system for each of the two 150,000 m3/day plants has 14 Memcor CS 900 units (see first column of Table 9.6) deigned at a flux of 52 lmh (30 gfd) and does use coagulants.