Membrane and Desalination Technologies - TCE Moodle Website

246 L.K. Wang et al.
Fig. 6.7. Schematic of spiral-wound membrane module.
for complete systems by a factor of three, from around US$ 1,400/m 2 to as low as US$ 370
per m 2 membrane area installed. This price drop occurred within a few months. Since 1989,
the prices have declined further. In early 2001, the price for a pharmaceutical system was
typically US$ 200–300 per m 2 . Dairy systems typically sold for US$ 150–250 per m 2 and
water systems for US$ 70–150 per m 2 (20).
In order to calculate the cost per unit of product, the capital costs are depreciated over a
period of time, often 10 years. And the operational cost can be divided into four parts: energy
requirement; membrane replacement; labor; maintenance.
Table 6.3 shows typical recoveries, TMPs, power requirements, consumption, and resulting
energy costs of different membrane filtration process. Membrane cost was estimated from
fluxes obtained in experiments and the membrane area required to produce 1,000 m 3 /day
product water (21).
A computer program, named the Water Treatment Cost Estimation Program (WTCost) can
be used to estimate costs of water treatment (including pretreatment and posttreatment)
processed employing MF, UF, NF, RO, and ED. The program has been tested by industry
experts, and it has been shown to accurately project true water treatment costs for a number of
plants (22).