The RSL Membranes™ are NSF approved for potable water treatment. The typical potable water treatment system design considered for the RSL Membrane™ is to use it prior to a UF, NF or RO membrane. The quality of water from the RSL Membrane™ will be similar to the quality of water from a UF membrane. As a result, the UF or NF or RO membranes after the RSL Membrane™ will have a long filtration run without chemical enhanced backwash (CEB) and clean in place (CIP) requirements. The objective is to simplify water treatment for small communities while also ensuring a safe supply. RSL Membranes™ offer longer filtration runs before needing to clean the membranes (2 month to 12 months). To ensure a high-quality water treatment, conventional UF, NF or RO membranes can be used as the certified final filtration barrier. The longer filtration runs will reduce the need for CEB and CIP thereby allowing for third party cleaning or offsite cleaning and eliminating the complexity for a small community operator.
Another option is the NSF 61 approved Harmsco disposable filter system. This technology uses a disposable filter https://www.harmsco.com/municipal_store/. The filter provides 3.7 log removal however the disadvantage to this filter is the waste of disposable filters. With the RSL Membrane™ in front of the Harmsco disposable filter, the operator has no need for chemical cleaning. The local operator can easily replace the disposable UF filters. The RSL Membrane™ pretreatment will provide the added benefit of infrequent UF filter replacement
Recently a consultant’s cost evaluation was undertaken on a 50 m3/hr conventional UF membrane water treatment system which was compared to an RSL Membrane™ treatment system for potable water supply. The water quality feeding the membrane was a high-quality surface water with NTU less than 2 NTU. The RSL Membrane™ system was combined with an NSF certified UF disposable cartridge system. This configuration, with the RSL Membrane™ as the lead filtration technology, provides longevity in the certified barrier technology which relies on disposable cartridges. Table 1 below shows the total capital cost of construction of a 50 m3/hr. water treatment plant in USD $. The comparison is based on a conventional UF membrane with multimedia pretreatment. RSL Membranes™ have no pretreatment but use a UF disposable Cartridge system to provide the certified barrier.
