Ndma Articles & Analysis
26 articles found
According to the National Disaster Management Authority (NDMA), India faces nearly 7,000 flood-related incidents annually, impacting lives, property, and critical infrastructure. ...
However, in the presence of organic matter, even at low concentrations, chlorine-based chemicals can produce a range of potentially carcinogenic by-products including trihalomethanes (THMs), haloacetic acids (HAAs) and nitrosodimethylamine (NDMA), whilst ozone can generate bromates from bromide in the raw water. ...
One of the major challenges of combining the highly volatile compounds from EPA Method 522 with the less volatile nitrosamines from EPA 521 was minimizing the retention time variability of the early eluting compounds (THF, 1,4-dioxane, and NDMA). Early runs collected under the final GC analytical conditions showed great retention time variation for these compounds. ...
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. ...
Additional samples were analysed to assess the impact of chloraminated backwash water on N-Nitrosodimethylamine (NDMA) formation and biological degradation of taste and odour compounds 2-methyl isoborneol (MIB) and geosmin in the filter media. ...
In the two nitrogen-rich natural organic matters (NOMs), transphilics and HPIs constituted half of the organic carbons and contributed 64–70% of the total N-nitrosodimethylamine (NDMA) formation. Ozonation-biofiltration reduced NDMA precursors in these two water sources but significantly enhanced NDMA formation in Suwannee River NOM. The increase ...
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. ...
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. ...
In WWTP O, the rates of production of N-nitrosodimethylamine (NDMA) (42%) and NDBA (58%) were the highest. In WWTP E, only NDBA (34%) was produced. In WWTP N, NPYR and NPIP (both >99%) were produced. NDMA FPNH2Cl values were very high in influent in all WWTPs. The efficiencies of removal of N-nitrosamine FPNH2Cl during ...
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. ...
Besides dimethylamine, the well-known precursor of nitrosamines, 3-(N,N-dimethyloctylammonio)propanesulfonate (3-N,N-DAPSIS) inner salt and benzyldimethyltetradecylamine (benzalkonium chloride, BKC) were suggested as important nitrosamine precursors. 3-N,N-DAPSIS could form about 1,000 ng/L of N-nitrosodimethylamine (NDMA) and more than 1,000 μg/L of THMs. More than 150,000 ng/L ...
Likewise N-Nitrosodimethylamine (NDMA), a toxic and suspected carcinogen can also be removed by using UV light. ...
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. ...
The model was applied to three model compounds (atrazine, ibuprofen and NDMA) in two different pilot reactors, and it has been shown that reactor performance can be fairly predicted by applying this ‘UVPerox’ model. ...
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 ...
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 formation of seven nitrosamines, including NDMA. ...
Due to the confluence of the Arato River, NDMA concentration in the Hirose River increased (up to 61 ng/L). The NDMA in the Arato River was due to industrial discharge from a livestock processing plant located near the river. There were three discharges at the plant, with NDMA concentrations of 78, 11, and 33,000 ng/L. The industrial discharges ...
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 amount of bromide added would result in BrCl being converted into HOBr, which is a weaker oxidant than HOCl. ...
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. ...
Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar ...