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Finding The Right Pretreatment Mix For RO/Ion Exchange Systems


Advanced Filtration Proving Effective

Smart defense benefits the entire team. Having an ffective, durable water pretreatment system in advance of reverse osmosis (RO) or ion exchange systems is the first, most critical line of defense ensuring smooth, more trouble-free performance downstream.

It’s especially true when dealing with today’s RO and ion exchange technologies, which require TSS (total suspended solids) of 0.1-0.5 mg/L, turbidities of 0.1-1 NTU (nephelometric turbidity units) and SDIs (silt density index) values of <5, and ideally <3.

Most suppliers of ion exchange resin would advise removal of suspended solids to at least 1 mg/l or better through some form of pretreatment and that some, but not all, of the residual solids that accumulate within resin beds be removed by periodic backwashing of the resin. If allowed to accumulate, these solids can adversely impact water and regenerant chemical distribution, will ultimately increase pressure drop, and degrade water quality and quantity. Furthermore, longer term fouling by solids can make subsequent resin cleaning much more difficult, if not impossible.