With tight security and restricted access, biohazard lab facilities need ultrapure water treatment systems that can be serviced without compromising water quality, human safety or the facility’s environment.

Water used in research at these laboratories needs to be extremely pure, but tap water typically contains particulates, dissolved organics and dissolved inorganics, which can impact the testing results. To remove the contaminants and ensure water quality that meets ASTM standards, it must be treated with a combination of technologies.

To meet the special needs of biohazard laboratories, Siemens Water Technologies, Shrewsbury, Mass., offers a standard ultrapure water treatment system, which includes a pretreatment cartridge to remove chlorine and particulates; a reverse osmosis system with storage reservoir; and an ultrapure lab-water polishing system. The system meets 18.2 MΩ ultrapure water with less than 3 ppb total organic carbon and less than 0.001 EU/ml endotoxin levels. When fitted with an optional bioguard filter, the system further removes biological contamination.

In addition, the system is self-contained on a single roller cart that can be transported from the laboratory to a decontamination area or out to an engineer for servicing. The system is fed from a tap-water source.

Incoming tap water enters the water treatment system through external and internal pretreatment cartridges to remove chlorine and particulates. The water then flows into the reverse osmosis membranes, where organics, total dissolved solids and bacteria are reduced. Reverse osmosis cartridges remove 95 percent of the monovalent ions and 98 percent of the divalent ions as well as organics with a molecular weight greater than 200.

The product water then feeds into the storage reservoir, where the pre-purified water is pumped to the laboratory's water-polishing unit, at which point it flows through deionization packs that remove oxidized organics and ions. Then the water flows through a dual-wavelength ultraviolet sterilizer, which disinfects the water and reduces total organic carbon levels. The water undergoes a final ultrafiltration purification step to remove pyrogens and nucleases. An optional point-of-use bioguard filter can be added for microbial reduction at the dispense point. For more information, go to www.water.siemens.com.