AWWA ACE93238

The practice of installing treatment to remove Radon 222 (Rn 222) from drinking water is not frequently seen. However, current USEPA proposals will require the installation of radon treatment systems in approximately 30,000 US water systems over the next few years. As radon contamination generally occurs in small groundwater supplies, this huge impact will be felt by a small and select fraction of community water systems in the US. These proposed regulations limit the amount of radon allowed in community and nontransient, noncommunity water systems to 300 pCi/l. The national average concentration by comparison is about 650 pCi/l. In the proposed rule, EPA defines the Best Available Treatment (BAT) to remove radon from drinking waters as Packed Tower Aeration (PTA). This technology is well suited to radon removal due to its highly volatile nature. In fact, the Henry's law constant for radon is about 2260 which places it over carbon dioxide in volatility. In addition to PTA, radon can be stripped by a number of other conventional and nonconventional aeration systems. Additionally, radon is readily adsorbed onto Granular Activated Carbon (GAC). Studies illustrating the effectiveness of this treatment technique are generally available. While retained by the GAC, radon rapidly disintegrates through a series of "daughter" radionuclides, ending up as lead 210 (Pb 210) with a radioactive 1/2 life of about 20 years.

Product Details

Published:

01/01/1993

ISBN(s):

0898677157

Number of Pages:

8

File Size:

1 file , 280 KB