Toray UF membranes online in North Dakota

An ultrafiltration UF system in North Dakota, USA, has become the first large municipal drinking-water system in the US to use Toray HFS-2020 UF membrane modules.

The 2 MGD (7,600 m³/d) UF system, commissioned in New Town in June 2011 by Wigen Water Technologies, is one of three on the Fort Berthold Indian Reservation being set up to meet the demand for improved drinking water infrastructure driven by the oil boom in the region.

A 1.4 MGD (5,300 m³/d) system at Mandaree commissioned in July 2011 also uses Toray’s UF membrane modules, as will a 1 MGD (3,800 m³/d) system at Twin Buttes scheduled to start-up in early 2012. Each of these systems draws water from Lake Sakakawea, which is located on the upper reaches of the Missouri River.

Toray’s HFS-2020 module is a pressurized outside-in module with hollow fiber polyvinylidene fluoride (PVDF) membranes having a nominal pore diameter of 0.02 µm. The membrane surface area in each module is 775 ft² (72 m²).

With such a high surface area per module and approval by the Californian Department of Public Health (CDPH) for at least 4-log Giardia and Cryptosporidium removal at a maximum flux of 120 gfd (204 L/m²h), UF systems using Toray’s HF-2020 module have a smaller footprint than other commercially available UF systems and therefore potentially a lower overall capital cost.

“We have had a very positive response to our entry into the UF market from engineers and municipalities and with the availability of the Toray UF membranes to complement our reverse-osmosis (RO) equipment, we can now provide fully integrated membrane systems” said Jeff Wigen, president of Wigen Water Technologies. “Our first integrated UF/RO system is a 4.5 MGD (17,000 m³/d) installation currently under construction and due to start up later this year.”