Challenge

The incoming water supply used by a Midwestern company contained high levels of suspended matter that was adversely affecting production and wreaking havoc with the plant’s existing reverse osmosis (RO) system.  While the company had previously purchased an RO system for increased production requirements, they were not aware of the need for pretreatment equipment to treat the suspended matter.   

Also referred to as total suspended solids or TSS, suspended matter consists of tiny insoluble particles in water that include grit, silt, clay, ferric iron and other precipitates.  As is usually the case, the suspended matter was adhering to the surface of the RO membranes and interfering with the passage of water through the membrane which resulted in:

• Membrane fouling, particularly the first elements of the first stage
• Increased pressure drop, thereby causing lower flows
• Greater pump discharge pressure used to overcome fouling, thereby leaving less pressure to drive the water through the membranes
• Frequent cleanings and unplanned downtimes

Plant personnel needed a quick, reliable solution that would maximize production and protect the existing RO system.

Solution

Siemens provided a multimedia filter to treat the suspended matter in the feed water to the RO system and ensure maximum effluent quality:

• No membrane fouling
• Flow rates meet the design parameters
• Adequate pressure to drive the water through the membranes

These multimedia filters are ideal for all industries where the incoming water contains suspended solids.  The filters are simply installed upstream from the RO system and remove the suspended matter from the feed water prior to it entering the RO system.

Results

Suspended matter in water is a common problem faced by a multitude of plants throughout the world.  By using multimedia filters, the suspended solids are removed to ensure:

• Maximum performance
• Consistent quality and quantity of water
• Minimal unscheduled downtimes
• Protection of downstream equipment
• Protection of RO membranes from fouling