Membrane Technologies

Synder Filtration recently released a new line of polyacrylonitrile UF membranes specially designed for oil separation and removal in wastewater treatment applications. These membranes join the broad range of molecular weight cut-offs available within Synder Filtration’s ultrafiltration  product line, and consist of PX (400kDa), PY (100kDa), and
PZ (30kDa).

The development of these membranes was driven, in part, by the rise in discharge regulations by environmental agencies. These strict regulations have pushed manufacturers to implement various forms of oil removal technology in order to reuse and discharge large volumes of wastewater. The removal of oil is a necessity, as its presence hinders many downstream processes and increases maintenance costs for manufacturers. Compared to other oil removal techniques, ultrafiltration technology has proven to be a viable alternative, with regards to both cost and efficiency, for the removal of oil in wastewater applications.

Synder’s polyacrylonitrile (PAN) ultrafiltration (UF) membranes serve as a more hydrophilic, lower-fouling alternative to PVDF membranes, which are also typically used for similar applications involving wastewater treatment. With molecular cut-offs ranging from 30kDa to 400kDa, these membranes provide manufacturers with a variety of sizes and configurations that can also be customized to fit their existing systems. All three types are available in both flat sheet  and spiral-wound element configurations, with feed spacers varying in thickness from 24mil to 80mil depending on the solid content of the incoming feed stream. Additionally, these membranes provide good resistance to pH and temperature, making them suitable for use in other industrial applications such as oil/water separation and oil removal in mining tailing ponds and textile wastewater facilities.  

A recent case study  was performed at Synder’s HQ facility in Vacaville, CA. Synder’s PX membrane and a polyacrylonitrile membrane of a leading competitor were evaluated for their flux performance and oil retention characteristics. The test was performed using a flat sheet cross-flow filtration system run at 15psi, with a cross-flow rate of 0.5gpm, and the feed solution was kept at ambient temperature while being recirculated in the system. The feed composition contained a mixture of 1,000ppm emulsified I-19 paraffinic vacuum pump oil with 500ppm sodium dodecyl sulfate as an emulsifying agent, and both flux and rejection were evaluated. Overall, Synder’s PX membrane demonstrated superior clean water flux and a competitive steady state flux when challenged with emulsified oil. Rejection was calculated using UV-Vis and was determined to be >99%, making it quite suitable for use in similar oil removal applications.

These results indicate that Synder’s PAN ultrafiltration membranes are an effective form of wastewater treatment for applications involving oil separation and removal and have the potential to decrease operating costs and reduce environmental risks.

About Synder Filtration

With over 25 years of experience in the membrane filtration industry, Synder continues to put a focus on specialty process applications and custom membrane solutions. The addition of PAN membranes to Synder’s ultrafiltration line provides even greater flexibility in separation process development. As a financially independent membrane manufacturer, California-based membrane manufacturer, Synder invests heavily in R&D and application development and delivers exceptional lead times and responsiveness.