Radioactive Materials in Biosolids

Abstract

past experience, there have been concerns that radioactive materials could concentrate in sewage sludge and The Nuclear Regulatory Commission (NRC) announced the availash and pose a threat to the health and safety of POTW ability of three new documents concerning radioactive materials in sewage sludge and ash from publicly owned treatment works (POTW). workers or the general public. One of the documents is a report presenting the results of a volunteer As a result of interest from the U.S. Congress, the survey of sewage sludge and ash samples provided by 313 POTWs. Interagency Steering Committee on Radiation Standards The second document is a dose modeling document, using multiple (ISCORS) conducted a survey of radioactive material in exposure pathway modeling focused on a series of generic scenarios, sewage sludge and ash. The committee also performed to track possible exposure of POTW workers and members of the dose modeling of the survey results to address radiation general public to radioactivity from the sewage sludge or ash. The concerns and to estimate typical levels of radioactive third document is a guidance report providing recommendations on materials in POTWs around the country. The committee the management of radioactivity in sewage sludge and ash for POTW then provided recommendations on the management of owners and operators. This paper explains how radioactive materials radioactivity in sewage sludge and ash for POTW ownenter POTWs, provides criteria for evaluating levels of radioactive material in sludge and ash, and gives a summary of the results of the ers and operators, including guidance on evaluating survey and dose modeling efforts. Average Typical range Radiation source exposure of variability Sv yr Ϫ1 ‡ WHY IS THERE RADIOACTIVE Natural sources MATERIAL IN SEWAGE AND Terrestrial 300 100-800 SEWAGE SLUDGE? Radon 2000 300-8 200 Cosmic 300 300-800 Radioactive materials are an ever-present component Internal 400 200-1 000 of the natural environment and are also produced through Man-made sources some human activities. Generally, the presence of radio-Medical 500 active materials is a concern only when concentrations Consumer products 100 Other (nuclear fuel cycle 10 become sufficiently elevated above background levels and occupational) (Table 1) to potentially pose a health risk, or in cases Total where the ability of a POTW to use or dispose of the 3600 900-10 800 sewage sludge or ash is limited. † Sources: National Council on Radiation Protection and Measurements Publicly owned treatment works can receive naturally (1987a) for average exposure values, Huffert et al. (1994) and Fisher occurring radioactive material (NORM) or man-made (personal communication, 2003) for ranges of variability. ‡ 1 microsievert (1 Sv) ϭ 0.1 milliroentgens (0.1 mrem).

Levels and behaviour of radionuclides in water treatment plants : the case of the Barcelona metropolitan area urban water cycle

“…One previous relevant study on this field is Bastian et al (2005) giving information about 311 sewage sludge samples from WWTPs located in the United States and 35 sewage sludge ash samples, where 44 different radionuclides from diverse origins (natural and artificial) were found. In the review from Fonollosa et al (2015) a total of 28 radionuclides were found in the sludges from the different DWTPs studied.…”

“…A relevant study about the presence of radionuclides in WWTPs is Fischer et al (2009) which reported the presence of medically-derived 99m Tc and 131 I in wastewater, sludges, sewage effluent and in sediments. Although some studies reported levels of medically-derived radionuclides in WWTPs (Barci-Funnel et al, 1993;Dalmasso et al, 1997;Bastian et al, 2005;Rose et al, 2012;Punt et al, 2007;Fenner and Martin 1997;Montaña et al, 2013a;Barredo 2010;Chang et al, 2011;Mc Gowan et al, 2014;Martínez et al, 2018), very few studies have gone one step beyond and identify relationships of the levels found with other factors (Zannonni et al, 2018;Hormann and Fischer 2018).…”

“…Many articles have been devoted to the analysis of the nuclear medicine (NM) radionuclides content of sewage effluent and its discharge into the environment (Carvalho et al, 2013;Fischer et al, 2009;. However, very few articles provide an integral picture of the behaviour and fate of medically-derived radionuclides in a wastewater treatment plant (WWTP), since, in most cases, the presence of such isotopes is based on only one kind of samples: sewage sludge (Bastian et al, 2005) At a worldwide level can be cited the studies of (Rose et al, 2012) in the USA and (Chang et al, 2011) in Korea for different sized plants (3,000-1,400,000 m 3 •d −1 ), however, they provide results mainly on sewage effluent. Among several conclusions, in these previous studies, it was pointed out that it is of the utmost importance to sampling the inflow, the effluent and sewage sludges of the WWTPs in order to determine their radioactivity content, and consequently, to know the behaviour of the medically-derived isotopes in the different stages of the treatment.…”