US EPA

1427046 

Technical Report 

Particle count monitoring of reverse osmosis water treatment for removal of low-level radionuclides 

Moritz, EJ; Hoffman, CR; Hergert, TR 

1995 

NTIS/02980667_3 

GRA and I 

GRA and I 

Laser diode particle counting technology and analytical measurements were used to evaluate a pilot-scale reverse osmosis (RO) water treatment system for removal of particulate matter and sub-picocurie low-level radionuclides. Stormwater mixed with Waste Water Treatment Plant (WWTP) effluent from the Rocky Flats Environmental Technology Site (RFETS), formerly a Department of Energy (DOE) nuclear weapons production facility, were treated. No chemical pretreatment of the water was utilized during this study. The treatment system was staged as follows: multimedia filtration, granular activated carbon adsorption, hollow tube ultrafiltration, and reverse osmosis membrane filtration. Various recovery rates and two RO membrane models were tested. Analytical measurements included total suspended solids (TSS), total dissolved solids (TDS), gross alpha ((alpha)) and gross beta ((beta)) activity, uranium isotopes (sup 233/234)U and (sup 238)U, plutonium (sup 239/240)Pu, and americium (sup 241)Am. Particle measurement between 1--150 microns ((mu)) included differential particle counts (DPC), and total particle counts (TPC) before and after treatment at various sampling points throughout the test. Performance testing showed this treatment system produced a high quality effluent in clarity and purity. Compared to raw water levels, TSS was reduced to below detection of 5 milligrams per liter (mg/L) and TDS reduced by 98%. Gross (alpha) was essentially removed 100%, and gross (beta) was reduced an average of 94%. Uranium activity was reduced by 99%. TPC between 1-150(mu) were reduced by an average 99.8% to less than 1,000 counts per milliliter (mL), similar in purity to a good drinking water treatment plant. Raw water levels of (sup 239/240)Pu and (sup 241)Am were below reliable quantitation limits and thus no removal efficiencies could be determined for these species. 

Waste Water Treatment; *Reverse Osmosis; *Radioactive Wastes; *Meetings; Chemical Removal(Water Treatment); Radiation Counters; Americium 241; Particulates; Plutonium 239; Plutonium 240; Radiochemical Separation; Chemical Analysis; Uranium 233; Uranium 234; Uranium 238; Performance Evaluation; Alpha Detection; Beta Detection; Bench-Scale Experiments; EDB/400100