PureSep UF Ultrafiltration Membrane Systems

Conventional filtration methods are often based on a multitude of processes including sand filtration and traditional media filtration. They require consistent raw water quality to deliver quality filtrate, which is not always possible. They also don’t provide an absolute barrier. Traditional media filters typically remove particles down to about 5 microns. Ultrafiltration membrane technology, on the other hand, do not suffer from those limitations.

Ultrafiltration (UF) is carried out using hollow fiber membrane technology to deliver sub-1-micron filtration in either inside to outside, outside to inside configurations. The ultrafiltration process removes suspended solids and reduces turbidity while providing a sterile barrier, meeting increasingly stringent water-quality standards around the world, and providing a stable, reliable, and consistent water quality.

PureSep UF skid with hollow fiber membranes: This ultrafiltration equipment will be deployed to treat stagnant quarry water. Once treated, the filtrate will reduce the need for expensive towns water supply.

Envirogen’s PureSep UF ultrafiltration membrane range is operated in a dead-end filtration mode and uses 462.8ft² (43m²) hollow fiber membranes in an inside to outside configuration to optimum back-pulse performance. Inside-out technology means the feed passes along the inside of the lumen and through the membrane wall as purified water. This approach minimizes dead space and eliminates the potential of solids build-up within the module housings.

Each hollow fiber membrane is constructed from a blend of hydrophilic polyethersulphone (PES) and polyvinylpyrrolidone (PEV) chemistry, providing market-leading permeability rates. Available either as 150 kilodalton (kDa) or 10kDa molecular weight cut-off (MWCO) ratings, they deliver excellent removal of suspended solids, bacteria, and log 4 reduction of viruses.

PureSep UF excels in the following process applications:

• Reverse osmosis (RO) pre-treatment
• Potable water production
• Municipal and industrial wastewater treatment
• Food and beverage applications
• Water recycling

For over 20 years, we’ve been supplying solutions for ultrafiltration equipment. This experience led to the development of our PureSep UF range of systems which are supplied as ready-to-install ‘blocks’. Back-pulsing and chemically enhanced back-pulsing equipment are also supplied as standard. Manufacturers can choose the configuration and bolt-ons to achieve process-specific clarification standards without the cost of a fully custom-made system.

Available with four modules and all the way up to fourteen, our standard range covers most applications, with flux-rates starting at 1.85 gpm/ft² (40 l/m2/hr) and up to 5.58 gpm/ft² (120 l/m2/hr).

150kDa ultrafiltration membranes – these hollow fiber membranes have smaller pore sizes than most of the widely available UF membranes in the water market, resulting in an increase in stability during the filtration process, with reduced pore blocking and higher virus log retention. 150kDa membranes are all delivered alongside stable filtrate flows, even on high fouling feed waters. Excellent at removal of suspended solids, turbidity, bacteria, and viruses.

10kDa ultrafiltration membranes – these membranes provide a 10kDa molecular weight cut off (MWCO). A unique polymer used in construction results in the membrane being extremely robust and resistant to high pressures. The pore size of the membrane material is narrow enough to remove colloidal silica making the membrane suitable for RO pre-treatment (i.e., boiler feed applications) as they can be operated at high trans-membrane pressures. Excellent for removal of colloidal silica, suspended solids, turbidity, bacteria, and viruses.

The Envirogen range of Puresep UF skid systems come complete with the following:

• Siemens S7 PLC control system for fully automated operation including a color HMI
• Inverter driven back-pulse pump that enables control to suit the process conditions
• Complete suite of dosing pumps for automatic chemical enhanced back-pulse sequences
• Skid mounted system that enables factory acceptance testing and minimum on-site installation requirements

Optional extras:

• Filtrate storage vessel for back-pulse operations
• Self-cleaning disk filter to protect lumens operating with large particle distribution

When you make the switch to PureSep UF you invest in future-proofed hollow fiber membrane technology. This filtration offers distinct benefits across all applications:

• Strong mechanical integrity for stabile filtration and consistent filtrate quality
• Improved OpEx performance and lower energy use and cleaning frequency, due to reduced pore blocking
• Low capital cost investment per ft²
• Remote monitoring and data trending available
• Future proofed flexibility – skids available with blanked membrane ports
• Specific hollow fiber membrane service packages available – designed to ensure optimum performance and profitability
• Ongoing support and full lifecycle value with service and maintenance packages

When used as a pre-treatment for reverse osmosis (RO), the PureSep ultrafiltration process also helps reduce fouling of the RO membranes, which can lead to reduced chemical cleaning frequency and consequently, lower operating costs and downtime. There’s also potential for operating the RO at higher flux, with fewer membranes and vessels — leading to lower capital cost for the RO system.

Our flexible, bench-top manual pilot plant systems accommodate a wide range of microfiltration and ultrafiltration hollow fiber membrane technology for comprehensive filtration tests. Our 0.5ft² (0.05m²) unit requires only limited feedstock and represents a scaled version of a full filtration solution. Detailed assessments on permeability and efficiency of back-pulse sequences can be achieved with only a 5-gallon (20-litre) sample.

An Envirogen benchtop ultrafiltration pilot plant.

On-site pilot plant trials can be conducted using mobile UF skids to confirm process stability and CIP efficacy. These provide 150 ft² (14m²) of membrane surface area and are able produce between 75-110 gallons/hour (350-500 litres/hour). These mobile plants are mounted to compact sized skids with forklift slots for easy offloading and on-site positioning.

An Envirogen PureSep UF mobile skid testing system.