An evaluation by the Drinking Water Treatment Systems program, a U.S. Environmental Protection Agency initiative, showed a Koch Membrane Systems, Inc. membrane filtration system effectively removed arsenic from drinking water.
Verification of Koch Membrane's TFC® - ULP4 Reverse Osmosis Module was conducted over a 34-day verification test period at the Spiro Tunnel Water Filtration Plant in Park City, Utah.
The system operated continuously during this time and achieved an average total arsenic removal of 99 percent, according to NSF International, which operates the Drinking Water Treatment Systems program in cooperation with the U.S. EPA
The total arsenic concentration in the feedwater averaged 60 micrograms per liter during the test period. The Koch Membrane Systems module reduced total arsenic to an average of 0.9 mg/L in the treated water.
The system also removed dissolved arsenic - which represented 70 percent of the arsenic in the feedwater - by 97 percent, from an average of 42 mg/L, to 1.3 mg/L.
"Arsenic removal by reverse osmosis filtration has been successfully accomplished for years, primarily outside the United States," said Randy Truby, vice president of sales and marketing for Koch Membrane Systems. "Increased awareness, and more stringent regulations have resulted in the NSF/ETV test program. Now agencies and municipalities that have an arsenic problem can access technical information providing them with the assurance they require before using it in their water treatment plants."
The Koch Membrane Systems module evaluated was a spiral-wound polyamide membrane with a fiberglass outer wrap enclosed in a typical membrane housing. The molecular weight cut-off for this system is approximately 100 daltons, and it is rated for a maximum pressure of 350 pounds per square inch. Normal design pressure for the system is 125 psi. The results of this evaluation of the system are not a guarantee of system performance.
Source: Koch Membranes