scholarly journals Relationship between organic precursors and N-nitrosodimethylamine (NDMA) formation in tropical water sources

2014 ◽  
Vol 12 (4) ◽  
pp. 736-746 ◽  
Author(s):  
Wang Qi ◽  
Lim Fang Yee ◽  
Hu Jiangyong
Keyword(s):  
Organic Nitrogen ◽  
Correlation Study ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Secondary Effluent ◽  
Small Molecular Weight ◽  
Tropical Water ◽  
Water And Wastewater ◽  
Organic Precursors ◽  
Emerging Dbps

The presence of organic compounds in water sources is one of the concerns in water treatment. They are potential precursors of disinfection byproducts (DBPs) and thus induce health problems in humans. Among the emerging DBPs, carcinogenic compound N-nitrosodimethylamine (NDMA) has been receiving attention during the last decade. This study examined the characteristics of organic components in various water sources and investigated their relationships with NDMA formation. Experiments were carried out on selected water samples from both natural water and wastewater. Results showed similar NDMA formation kinetics for both water sources. However, more contribution of NDMA precursors was found to be from the wastewater due to its higher organic nitrogen content. NDMA formation potential (NDMAFP) of secondary effluent ranged from 264 to 530 ng/L. A correlation study between organic compound characteristics and NDMAFP indicated that the majority of NDMA precursors came from dissolved organic nitrogen (DON) compound with small molecular weight (smaller than 500 Da), with correlation R2 = 0.898. Although secondary treatment removed more than 90% of NDMA precursors, the remaining precursors in secondary effluent would still pose a challenge for water quality.

Characterization of DON in IOM derived from M. aeruginosa and its removal by sunlight/immobilized TiO2system

RSC Advances ◽  
2015 ◽  
Vol 5 (51) ◽  
pp. 41203-41209 ◽  
Author(s):  
Cheng Liu ◽  
Jie Wang ◽  
Wei Chen ◽  
Haoqiang Zhu ◽  
Hongkai Bi
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Eutrophic Water

Dissolved organic nitrogen (DON) is now considered as one of the most important precursors of nitrogenous disinfection byproducts (N-DBPs), and the algae cells were the main source of DON in eutrophic water sources.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters

2012 ◽  
Vol 76 ◽  
pp. 153-161 ◽  
Author(s):  
Doris Sobral Marques Souza ◽  
Ana Paula Dores Ramos ◽  
Fabrício Flores Nunes ◽  
Vanessa Moresco ◽  
Satie Taniguchi ◽  
...  
Keyword(s):  
Water Sources ◽  
Southern Brazil ◽  
Chemical Parameters ◽  
Tropical Water

Agriculture, water and the environment: future challenges

2003 ◽  
Vol 3 (4) ◽  
pp. 51-57 ◽  
Author(s):  
G. Oron
Keyword(s):  
Supply And Demand ◽  
Water Source ◽  
Water Sources ◽  
Additional Treatment ◽  
Treated Wastewater ◽  
Secondary Effluent ◽  
Arid Zones ◽  
Runoff Water ◽  
High Quality ◽  
Future Challenges

Various countries in the Mediterranean Basin and other arid and semi-arid regions are facing a gap between water supply and demand. This gap is closely linked with agricultural production and environmental issues. It is probably due to small amounts of precipitation and low availability of natural water sources. Special ventures have to be undertaken in order to supply water at adequate quality for all requirements. These can be accomplished by development of additional water sources that currently are considered marginal. The additional sources include saline ground water, treated wastewater and runoff water and are usually required to augment the limited supply from the regional conventional high quality local sources. The paper presented options for development of the marginal water sources in arid zones in conjunction with minimizing the dependence on high quality water. Domestic secondary effluent is a valuable water source for reclamation however, additional treatment is required to use it for unrestricted purposes. It can be achieved primarily by implementation of the membrane technology, namely ultrafiltration (UF) and reverse osmosis (RO) stages.

Effect of pre-ozonation on N-nitrosodimethylamine (NDMA) formation from four drinking-water sources during subsequent chloramination

2019 ◽  
Vol 19 (6) ◽  
pp. 1816-1822
Author(s):  
X. B. Liao ◽  
L. Zhao ◽  
L. L. Shen ◽  
M. Y. Chen ◽  
C. Chen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Ammonia Concentration ◽  
Quality Parameters ◽  
Water Sources ◽  
Ultraviolet Absorbance ◽  
Drinking Water Sources ◽  
The World ◽  
Doc Concentration

Abstract Ozone has been widely used for water treatment all over the world. This study investigated the effects of pre-ozonation on N-nitrosodimethylamine (NDMA) formation from four drinking-water sources during subsequent chloramination. Moreover, relationships between NDMA and water-quality parameters (dissolved organic carbon (DOC), dissolved organic nitrogen (DON), hydrophobic fractions (HFs), positive-charged fractions (PCFs), ultraviolet absorbance at 254 nm wavelength (UV254), ammonia) were determined. The results indicated that NDMA formed directly by ozonation, but the concentrations (5.7–37.8 ng/L) were much lower than during chloramination (25.3–193 ng/L). Pre-ozonation slightly augmented NDMA formation from reservoirs, while it facilitated NDMA precursor destruction in the lake and river. The river was rich in organic matter, its DOC concentration was up to 4.97 mg/L, while the DON/DOC ratio (4.68%) was low; the lake possessed the most organic nitrogen and highest DON/DOC ratio (10.76%). HFs in reservoir #2 were low (1.27 mg/L), and the HFs/DOC ratio was especially high (73.4%). PCFs constituted 48.5–72.1% of DOC. UV254 values were in the range 0.081–0.175 cm−1. The ammonia concentration was high in the lake water (0.29 mg/L), while that in reservoir #2 was only 0.08 mg/L. There was a strong correlation between NDMA formation and the removal of ammonia, DON and PCFs.

scholarly journals Characteristics of Dissolved Organic Nitrogen in the Sediments of Six Water Sources in Taihu Lake, China

2019 ◽  
Vol 16 (6) ◽  
pp. 929 ◽  
Author(s):  
Xiaofan Yang ◽  
Xueyu Wei ◽  
Xiaoping Xu ◽  
Yu Zhang ◽  
Jincheng Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Drinking Water ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Taihu Lake ◽  
Water Sources ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Endogenous Release ◽  
Molecular Weight Fractions

KCl-extractable sediment dissolved organic nitrogen (KS-DON) extracted from sediments near drinking water intakes of six drinking water sources in Taihu Lake in China was partitioned into hydrophobic and hydrophilic fractions and high/low molecular weight fractions. The results showed that the total dissolved nitrogen (TDN) contents of the extracts ranged from 67.78 to 128.27 mg/kg. KS-DON was the main TDN species, accounting for more than 50%, with NH4+-N and NO3−-N averaging 30% and 20%, respectively. The molecular weight fractions of <1 kDa accounted for almost half of KS-DON. Hydrophilic compounds accounted for more than 75% of KS-DON. Three fluorescence peaks were identified: soluble microbial byproducts (A); protein-like substances (B); and humic acid-like substances (C). It is concluded that the KS-DON in Taihu Lake sources has higher bioavailability and higher risk of endogenous release. Ecological dredging and establishment of constructed wetlands are possible measures to reduce the release of endogenous nitrogen.

scholarly journals NDMA formation potential removal in treated effluent by UV/H2O2 process

2015 ◽  
Vol 6 (1) ◽  
pp. 156-166 ◽  
Author(s):  
Wang Qi ◽  
Hu Jiangyong
Keyword(s):  
Water Reuse ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Ultra Violet ◽  
Treated Wastewater ◽  
Activated Sludge Process ◽  
Formation Potential ◽  
Treated Effluent ◽  
Organic Precursors ◽  
H2o2 System

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 dosage of 100 ppm. Reaction time was 60 minutes. Two types of wastewater treated effluents were collected: activated sludge process (ASP) effluent and membrane bio-reactor (MBR) effluent. Results showed efficient dissolved organic carbon (DOC) removal (70%). Dissolved organic nitrogen (DON) removal was less efficient (20–30%). Eighty per cent of NDMAFP in ASP effluent was removed within 1 hour. However, no NDMAFP removal was discovered in MBR effluent. This indicated that the effect of the UV/H2O2 system on NDMAFP removal was water specific. A generation of intermediate NDMA precursors was observed in the ASP effluent. Results indicated that sufficient oxidation should be provided to reduce intermediate NDMA precursors and to achieve NDMAFP removal.

scholarly journals Adsorption of estrone on nanofiltration and reverse osmosis membranes in water and wastewater treatment

2002 ◽  
Vol 46 (4-5) ◽  
pp. 265-272 ◽  
Author(s):  
L.D. Nghiem ◽  
A.I. Schäfer ◽  
T.D. Waite
Keyword(s):  
Reverse Osmosis ◽  
Surface Waters ◽  
Natural Waters ◽  
Membrane Resistance ◽  
Secondary Effluent ◽  
Water And Wastewater Treatment ◽  
Natural Hormone ◽  
Trace Contaminant ◽  
Water And Wastewater ◽  
Reverse Osmosis Membranes

Adsorption of the trace contaminant estrone, a natural hormone and commonly abundant in surface waters and in treated as well as untreated wastewaters, to eight commercial nanofiltration and reverse osmosis membranes was investigated under well defined conditions. Experiments were conducted in stainless steel stirred cells by spiking trace levels (100 ng.L−1) of estrone into five different matrices, namely MilliQ water, a bicarbonate solution, synthetic natural waters containing natural organics, and secondary effluent. Results show that estrone is adsorbed to the membranes to varying degrees with extent of adsorption influenced by the feedwater composition with different mechanisms of association controlling adsorption to different membrane types. Increase in membrane resistance is typically observed to result in decrease in extent of estrone adsorption.

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