NDMA Articles
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Effects of pipe materials, orthophosphate, and flow conditions on chloramine decay and NDMA formation in modified pipe loops
This study examined the effects of pipe materials (iron, copper, lead and PVC) and orthophosphate on chloramine decay and N-nitrosodimethylamine (NDMA) formation under stagnant, laminar and turbulent conditions using modified pipe loops. As expected, chloramine decay rates generally increased with increasing flow velocity. In the presence of orthophosphate, chloramine degradation in the iron ...
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Source of
N -nitrosodimethylamine in river waters of the upper Tone River basin in JapanThe presence of N-nitrosodimethylamine (NDMA) in the Hirose River and its tributaries, located in the upper Tone River basin, in the Kanto region of Japan, was investigated. NDMA was detected at high levels in the Arato River, one of the tributaries of the Hirose River, at high concentrations (up to 2,100 ng/L). Due to the confluence of the Arato River, NDMA concentration in the Hirose River ...
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Nitrosamine formation from the oxidation of secondary amines
The nitrosamines are potent carcinogens which can be formed as by-products during water treatment. Much recent research activity has been focussed upon the formation, occurrence and control of N-nitrosodimethylamine (NDMA) in particular. In this study, seven secondary amines were oxidised by chlorine, ozone, and UV-irradiation, with and without post-chloramination, to quantify the effect on the ...
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N -nitrosamine formation during chlorination/chloramination of bromide-containing waterThis study investigated the impact of bromide on the formation of N-nitrosamines during chlorination and chloramination, and tried to identify the reactive intermediates responsible for variations in the yield of N-nitrosamines. As an intermediate of the reaction between bromide and HOCl, bromine chloride (BrCl) may improve the yield of N-nitrosodimethylamine (NDMA) formation. But increasing the ...
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Adsorption/reduction of N-dimethylnitrosamine from aqueous solution using nano zero-valent iron nanoparticles supported on ordered mesoporous silica
N-Dimethylnitrosamine (NDMA) has aroused increasing concern among public health agencies. It is necessary to develop some effective methods to remove NDMA from drinking water. A reductive process has been investigated as an alternative treatment method for NDMA removal from water. In this manuscript, zero-valent iron nanoparticles (ZVINPs) were synthesized, and then supported on ...
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Scale-up of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA) and its Advantages Over Low Pressure UV Systems
Untitled Document Recently there has been considerable concern in California about the detection of N-nitrosodimethylamine (NDMA) in drinking water at levels as high as 900 ppt. NDMA was found to be a carcinogen in animals and assessed as a Class 1 carcinogen. It is currently listed as a priority pollutant on the US EPA National Priorities List. California ...
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Application of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA)
N-nitrosodimethylamine (NDMA) was first detected in 1990 as a problem pollutant in drinking water wells at levels as high as 3,000 ppt in Elmira, Ontario, Canada. The waste from a large chemical plant over many years had led to the contamination of the drinking water wells for the community. After extensive evaluation and testing, it was determined that UV photolysis was the most effective ...
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Evaluating Henry's law constant of
N -Nitrosodimethylamine (NDMA)N-Nitrosodimethylamine (NDMA), a potential carcinogen, may contaminate the groundwater when the reclaimed wastewater is used for irrigation and groundwater recharge. Henry's law constant is a critical parameter to assess the fate and transport of reclaimed wastewater-borne NDMA in the soil profile. We conducted a laboratory experiment in which the change of NDMA concentration in water exposed to ...
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Effects of natural organic matter and nitrate on the behavior of nitrosodimethylamine during ultraviolet irradiation and chloramination
Nitrosodimethylamine (NDMA), a potent carcinogen, is found in natural and engineered water systems. Ultraviolet (UV) treatment is potentially a useful tool for controlling NDMA at water purification plants. However, a recent study has reported that UV/advanced oxidation process (AOP) treatment may provide a source of NDMA precursors. Therefore, we investigated the effect of UV treatment on the ...
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Occurrence of N-nitrosodimethylamine precursors in wastewater treatment plant effluent and their fate during ultrafiltration-reverse osmosis membrane treatment
The formation of N-nitrosodimethylamine (NDMA) is of major concern among wastewater recycling utilities practicing disinfection with chloramines. The NDMA formation potential (FP) test is a simple and straightforward method to evaluate NDMA precursor concentrations in waters. In this paper we show the NDMA FP results of a range of tertiary wastewater treatment plants that are also the source for ...
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Effects of ozonation and biological filtration on the formation of nitrogenous disinfection byproducts during chloramination
This study investigates the formation potential (FP) of nitrogenous disinfection byproducts and haloacetic acids (HAAs) during ozonation and biofiltration. Ozonation of raw waters was performed in batches with 1 mg O3/mg dissolved organic carbon (DOC). The ozonized waters were subsequently passed through a biofilter with 25 minutes of empty bed contact time. The results show that the ...
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Application of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA)
Untitled Document N-nitrosodimethylamine (NDMA) was first detected in 1990 as a problem pollutant in drinking water wells at levels as high as 3,000 ppt in Elmira, Ontario, Canada. The waste from a large chemical plant over many years had led to the contamination of the drinking water wells for the community. After extensive evaluation and testing, it was ...
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Scale-up of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA) and its Advantages Over Low Pressure UV Systems
Recently there has been considerable concern in California about the detection of N-nitrosodimethylamine (NDMA) in drinking water at levels as high as 900 ppt. NDMA was found to be a carcinogen in animals and assessed as a Class 1 carcinogen. It is currently listed as a priority pollutant on the US EPA National Priorities List. California has set an 'action level' of 20 ppt for NDMA. NDMA is ...
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The Alamitos Barrier Recycled Water Project
Groundwater pumping in the Los Alamitos, California area over the last century has caused groundwater levels to drop, allowing seawater to intrude into the local groundwater aquifer. To prevent additional infiltration by seawater, a coastline barrier of wells injecting fresh water has been in place since 1965. Until recently, imported potable drinking water was injected into the aquifer. However, ...
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NDMA formation potential removal in treated effluent by UV/H2O2 process
NDMA formation from treated wastewater is one of the concerns in water reuse. This study focused on NDMA formation potential (NDMAFP) removal in wastewater treated effluent by UV/H2O2 technology. A UV/H2O2 system was tested for the removal performance on both organic precursors and NDMAFP. The system consisted of a low pressure ultra-violet (LPUV) with an intensity of 2 mW/cm2 and a H2O2 ...
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NDMA and seven other nitrosamines in selected UK drinking water supply systems
A survey for N-nitrosodimethylamine (NDMA) and seven other nitrosamines in six UK drinking water supply systems was conducted. At the time of the study, there was no NDMA data for UK drinking waters, and the study remains one of few globally to report concentrations of the other seven nitrosamines in water supply systems. Five of the six water supply systems were selected as probable to have ...
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Correlations between surrogate nitrogenous organic precursors and C-, N-DBP formation
Nitrosamines have been emerging as disinfection byproducts in drinking water using source water impacted with domestic wastewaters. Nitrogenous organic compounds are suggested as precursors of nitrosamines, but many of them have not been identified. This study investigated the correlations between nine selected nitrogenous organic compounds with different characteristics and corresponding ...
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Occurrence and fate of
N -nitrosamines and their formation potential in three wastewater treatment plants in JapanN-nitrosamines are well known as carcinogens present in the environment. However, studies of the occurrence and fate of N-nitrosamines and their N-nitrosamine formation potential (FP) in wastewater treatment plants (WWTPs) are lacking. Therefore, the objectives of this study were to determine the occurrence of N-nitrosamines in WWTPs, the FP of N-nitrosamines on chloramination during wastewater ...
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Cause of rapid monochloramine decay observed in treated water
Rapid monochloramine decay has been observed in the product water of three River Murray water treatment plants (WTPs). Previous investigations identified that rapid monochloramine decay was microbiological in nature and observed in samples taken after media filtration but was absent in filtered water samples from a fourth WTP of similar design. The filters at the WTP not exhibiting rapid ...
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Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate
Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. ...
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