Notification Level Research Articles

Notification levels related to the control of radioactive discharges

In relation to the management of elevated discharges of radioactive materials from the Paks Nuclear Power Plant, two different types of notification level are proposed. They relate to discharges which are above normal but below those associated with an emergency. The first is technically based (reference level) while the second (reporting level) is mainly based on considerations of public concern. The actions expected to be implemented if either of the levels is exceeded are summarized.

The Importance of Reverse Osmosis in Removal of Notification Level Chemicals and Selected Endocrine Disrupting Chemicals - A Pilot Study

The Importance of Reverse Osmosis in Removal of Notification Level Chemicals and Selected Endocrine Disrupting Chemicals - A Pilot Study

Perchlorate and nitrate treatment by ion exchange integrated with biological brine treatment

Groundwater contaminated with perchlorate and nitrate was treated in a pilot plant using a commercially available ion exchange (IX) resin. Regenerant brine concentrate from the IX process, containing high perchlorate and nitrate, was treated biologically and the treated brine was reused in IX resin regeneration. The nitrate concentration of the feed water determined the exhaustion lifetime (i.e., regeneration frequency) of the resin; and the regeneration condition was determined by the perchlorate elution profile from the exhausted resin. The biological brine treatment system, using a salt-tolerant perchlorate- and nitrate-reducing culture, was housed in a sequencing batch reactor (SBR). The biological process consistently reduced perchlorate and nitrate concentrations in the spent brine to below the treatment goals of 500 μg ClO 4 −/L and 0.5 mg NO 3 −-N/L determined by equilibrium multicomponent IX modeling. During 20 cycles of regeneration, the system consistently treated the drinking water to below the MCL of nitrate (10 mgNO 3 −-N/L) and the California Department of Health Services (CDHS) notification level of perchlorate (i.e., 6 μg/L). A conceptual cost analysis of the IX process estimated that perchlorate and nitrate treatment using the IX process with biological brine treatment to be approximately 20% less expensive than using the conventional IX with brine disposal.

N-nitrosodimethylamine (NDMA) removal by reverse osmosis and UV treatment and analysis via LC–MS/MS

N-nitrosodimethylamine (NDMA) is a probable human carcinogen found in ng/l concentrations in chlorinated and chloraminated water. A method was developed for the determination of ng/l levels of NDMA using liquid chromatography–tandem mass spectrometry (LC–MS/MS) preceded by sample concentration via solid-phase extraction with activated charcoal. Recoveries were greater than 90% and allowed a method reporting limit as low as 2 ng/l. Using this method, the removal of NDMA was determined for the Interim Water Purification Facility (IWPF), an advanced wastewater treatment facility operated by the Orange County Water District (OCWD) in Southern California. The facility treats effluent from an activated sludge treatment plant with microfiltration (MF), reverse osmosis (RO), and an ultraviolet-hydrogen peroxide advanced oxidation process (UV-AOP). Six nitrosamines were surveyed: NDMA, N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi- n-propylamine (NDPA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Only NDMA was detected and at all treatment steps in the IWPF, with influent concentrations ranging from 20 to 59 ng/l. Removals for RO and UV ranged from 24% to 56% and 43% to 66%, respectively. Overall, 69±7% of the original NDMA concentration was removed from the product water across the advanced treatment process and, in combination with blending, the final concentration did not exceed the California drinking water notification level of 10 ng/l. NDMA removal data are consistent with findings reviewed for other advanced treatment facilities and laboratory studies.

Simultaneous Bio-reduction of Nitrate, Perchlorate, Selenate, Chromate, Arsenate, and Dibromochloropropane Using a Hydrogen-based Membrane Biofilm Reactor

We tested the hypothesis that the H(2)-based membrane biofilm reactor (MBfR) is capable of reducing multiple oxidized contaminants, a common situation for groundwater contamination. We conducted bench-scale experiments with three groundwater samples collected from California's San Joaquin Valley and on two synthetic groundwaters containing selenate and chromate. The actual groundwater sources had nitrate levels exceeding 10 mg-N l(-1) and different combinations of anthropogenic perchlorate + chlorate, arsenate, and dibromochloropropane (DBCP). For all actual groundwaters, the MBfR reduced nitrate to less than 0.01 mg-N l(-1). Present in two groundwaters, perchlorate + chlorate was reduced to below the California Notification Level, 6 microg-ClO(4) l(-1). As(V) was substantially reduced to As(III) for two groundwaters samples, which had influent As(V) concentrations from 3 to 8.8 microg-As l(-1). DBCP, present in one groundwater at 1.4 microg l(-1), was reduced to below its detection limit of 0.01 microg l(-1), which is well below California's 0.2 microg l(-1) MCL for DBCP. For the synthetic groundwaters, two MBfRs initially reduced Se(VI) or Cr(VI) stably to Se degrees or Cr(III). When we switched the influent oxidized contaminants, the new oxidized contaminant was reduced immediately, and its reduction soon was approximately the same or greater than it had been reduced in its original MBfR. These results support that the H(2)-based MBfR can reduce multiple oxidized contaminants simultaneously.

Aplicación del método captura-recaptura en la evaluación del sistema de vigilancia epidemiológica de la enfermedad meningocócica en Tenerife (1999-2001)

Meningococcal Disease is mainly monitored passively on the Canary Islands, the regular Compulsory Disease Notification channels being used. The objective of this study includes describing the qualitative and quantitative aspects of this system and evaluating the exhaustiveness, by means of the capture-recapture system, of three information sources. This study covers the 1999-2001 period in Tenerife. The information was gathered from three sources: the Compulsory Disease Notification System, the Microbiology Laboratories and the hospital Minimum Basic Data Set. The Evaluation Protocols of the Monitoring System of the Atlanta Centers of Disease Control and Prevention were used. A log-linear model was used for estimating the number of cases. The calculations of the exhaustiveness and the 95% confidence intervals were done in the SPSS10 statistics package. The system was found to have an 84.9% sensitivity, and an 80.4% positive predictive value. The delay in notification (timeliness) fell within the 0.5-13-day range, averaging 3 days. The system was found to have a 76.6% overall acceptability. The exhaustiveness value was 98.1%. This disease is being monitored well, with a degree of sensitivity which would be revealing of a good notification level, also confirmed by its exhaustiveness. Although the positive predictive value is high, this could be indicative of the expeditious starting of antibiotic treatment which would hinder microbiological confirmation. The system is timely, affording the possibility of measures being taken for fast intervention.