Watertec cross-flow membrane filtration controls the effect of concentration polarization and the gel layer. It provides the most rapid, and hence economic, continuous membrane filtration.
RO is a moderate to high pressure (80-1200 psig) driven process for separating larger size solutes from aqueous solutions by means of a semi-permeable membrane. This process is carried out by flowing a process solution along a membrane surface under pressure. Retained solutes (such as particulate matter and dissolved salts) leave with the flowing process stream and do not accumulate on the membrane surface. The amount of salt and other impurities is often referred to as TDS, or total dissolved solids. The higher the TDS, the more feed pressure required.
Membranes are made with various rejection rates for different applications. KMS produces membrane polymers to cover the full spectrum of RO pressure ranges. One of these membrane types is the TFC (thin-film-composite) family. TFC-S ("S" for softening) and TFC-SR ("SR" for selective rejection) are ideal for low TDS or softening type applications. For higher purity permeate, the ULP (ultra-low pressure) line offers high water flux and salt rejection in a 125 psi class membrane.
When salt rejection is paramount, the TFC-HR (high rejection) elements offer 99.5% in standard form, or 99.7% in the Premium model. Typically used in brackish water applications with up to 2000-5000 mg/l TDS, they operate around 200 psi When the water is higher in TDS, the XR (extreme rejection) element comes into its own with 99.7% salt rejection and excellent silica and TOC (total organic carbon) removal too.
For seawater desalination, watertec offers the SS (single-stage) membrane in various sizes and configurations that allow optimum system design. In the Premium line, salt rejection is at least 99.75%! Many of the SS products are designed to run up to 1200 psi for high salinity/high recovery installations.
Watertec other main product line is known as ROGAŽ (Reverse Osmosis General Atomic). All ROGAŽ elements are made with a CA (cellulose acetate) blend membrane, which is resistant to organic fouling due to its smooth surface and neutral charge. The CA membrane operates well on chlorinated feeds, making it ideal for wastewater plants or other applications where chlorine is present or desired to minimize bacterial activity.
Watertec elements come in standard 40" lengths, or in the new MagnumŽ series at 60" long. The MagnumŽ series offers several benefits, including fewer interconnectors, o-rings, brine seals; higher active areas; greater productivity; and lower cost per installed gallon. |
