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AN EXPLORATORY ANALYSIS OF TRIHALOMETHANE AND HALOACETIC ACID FORMATION POTENTIAL MODELING OF CEDAR LAKEPeterson, Kristian 01 August 2019 (has links)
An exploratory analysis of the trihalomethane (THM) and haloacetic acid (HAA) formation potential (FP) of Cedar Lake in order to produce formation potential curves for both THM and HAA; determine the THMFP and rate constant and compare to previous studies on Cedar Lake; and develop modeling for the formation potential loss of HAA from laboratory analysis of the raw lake water. While extensive modeling approaches have been explored for THM formation on different water sources, not many have been applied to the reservoir that supplies water to the Carbondale Water Treatment Plant and even fewer have explored the formation and modeling of HAA. Data for this study was obtained through laboratory experiment by applying bleach as a substitute for free chlorine to raw water samples obtained from Cedar Lake and quenching the samples at specific time steps to stop the reaction. Samples were then analyzed for THM content using standard method EPA 524.2R4.1 and HAA content using standard method EPA 552.2. The observed peak formation was 641.2701 µg/L for THM and 426.8 µg/L for HAA, but modeling fitted to the laboratory results indicated that a lower FP provided a better fitting of the data. A detailed analysis of the formed THM and HAA compounds indicated that a model produced for each compound resulted in more appropriate fitting by being able to account for the differing reaction rates and limiting factors of each reaction.
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The Generation of Disinfection By-Products during Advanced Drinking Water Treatment ProcessesYang, Chia-yu 01 July 2008 (has links)
Disinfectants, such as chlorine, are widely used in water treatment plants to ensure the safety and quality of drinking water. However, these disinfectants easily react with some natural or man-made organic compounds in raw water and then form disinfection by-products (DBPs). For example, halogenated acetic acid (HAAs) and trihalomethanes (THMs) are two main components of DBPs.
The purposes of this study are to analyze the concentration of DBPs including HAAs and THMs in drinking water and investigate the distribution of DBPs in the processes of three advanced water treatment plants in southern Taiwan. The analytical method of HAAs is based on the USEPA Method 552.3 and THMs is analyzed by headspace solid-phase microextraction(HS-SPME). Moreover, some factors which may influence the formation of DBPs such as dissolved organic carbon (DOC) and water temperature are also analyzed to further discuss the relation to the generation of DBPs. Through this study, the results could be the reference for operation control in water treatment plants and regulation setting in Taiwan.
The samples of drinking water were collected in three advanced water treatment plants in southern Taiwan from June 2007 to April 2008. The analyzed HAA9 results were 28.71 ¡Ó 14.77£g g / L in Plant A, 24.43 ¡Ó 15.70 £g g / L in Plant B, 28.91 ¡Ó 14.38 £g g / L in Plant C. Comparing the HAA5 results with the maximum contaminant level (MCL) in USEPA, it was clearly found that all the values were under the standard of 60 £g g / L. As to THMs, the results were 9.99 ¡Ó 3.39£g g / L in Plant A, 0.94 ¡Ó 2.12 £g g / L in Plant B, 28.91 ¡Ó 14.38 £g g / L in Plant C and greatly under the EPA standard of 80 £g g / L in Taiwan. Furthermore, the major species of HAA9 in order were BCAA and TCAA while THMs was trichloromethane (CHCl3).
In the relation between DOC and DBPs, the results demonstrated that DOC was more relative to DBPs in raw water; meanwhile, the water temperature did not show great relation. In general, despite the poor correlation, it was still could conclude that the concentration of DBPs increases with the increase of DOC and temperature.
In conclusion, the research results showed that the removal efficiency of DBPs in Plant A and B (UF/RO system) is greater than Plant C (Biological Activated Carbon system, BAC system ), and all three advanced water treatment plants could show greatly effectiveness in drinking water quality improvement. However, higher concentration of bromine products in HAAs was discovered in this research. It was suggested that the phenomenon should be further discussed and controlled.
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Effects of Phosphate-based Corrosion Inhibitors on Disinfectant Stability and HAA/NDMA Formation when in Contact with Copper, Iron, and LeadHong, Zhang 08 January 2013 (has links)
This research examined the impacts of water quality, phosphate-based corrosion inhibitors and pipe wall exposure on free chlorine (HOCl)/chloramine (NH2Cl) degradation and haloacetic acid (HAA)/N-nitrosodimethylamine (NDMA) formation in simulated distribution system water mains and household plumbing at bench-scale and pilot scale.
In bench-scale bottle tests, the reactivity of fresh/pre-corroded pipe materials with HOCl/NH2Cl in decreasing order was: ductile iron, copper, lead. The addition of phosphate-based corrosion inhibitors generally increased HOCl/NH2Cl degradation for fresh iron coupons, but decreased HOCl/NH2Cl decay only for fresh copper coupons. Generally, these corrosion inhibitors did not impact HAA formation.
Copper corrosion products, including Cu(II), Cu2O, CuO and Cu2(OH)2CO3, catalyzed HAA and NDMA formation. For HAAs, copper catalysis increased with increasing pH from 6.6 to 8.6 and/or increasing concentrations of these copper corrosion products. Interactions of copper with natural organic matter (NOM), likely by complexation, and the subsequent increase in the reactivity of NOM were proposed to be the primary reason for the increased HAA formation.NDMA formation increased with increasing Cu(II) concentrations, DMA concentrations, alkalinity and hardness but was inhibited by the presence of NOM. The transformation of NH2Cl to dichloramine (NHCl2) and complexation of copper with DMA were proposed to be involved in elevating the formation of NDMA at pH 7.0.
Finally, in pilot-scale modified pipe loop tests, copper catalysis of NDMA formation was confirmed, especially under laminar flow conditions, and iron was shown to possibly catalyze NDMA formation under turbulent conditions. Orthophosphate increased the catalytic effects of iron but decreased copper catalysis on NDMA formation by either modifying the properties of the iron-associated suspended particles or reducing the dissolved metal concentrations. Orthophosphate increased chloramine decay when in contact with iron, likely by promoting nitrite formation, but orthophosphate decreased chloramine decay for copper and lead by reducing the availability of metal corrosion products.
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Effects of Phosphate-based Corrosion Inhibitors on Disinfectant Stability and HAA/NDMA Formation when in Contact with Copper, Iron, and LeadHong, Zhang 08 January 2013 (has links)
This research examined the impacts of water quality, phosphate-based corrosion inhibitors and pipe wall exposure on free chlorine (HOCl)/chloramine (NH2Cl) degradation and haloacetic acid (HAA)/N-nitrosodimethylamine (NDMA) formation in simulated distribution system water mains and household plumbing at bench-scale and pilot scale.
In bench-scale bottle tests, the reactivity of fresh/pre-corroded pipe materials with HOCl/NH2Cl in decreasing order was: ductile iron, copper, lead. The addition of phosphate-based corrosion inhibitors generally increased HOCl/NH2Cl degradation for fresh iron coupons, but decreased HOCl/NH2Cl decay only for fresh copper coupons. Generally, these corrosion inhibitors did not impact HAA formation.
Copper corrosion products, including Cu(II), Cu2O, CuO and Cu2(OH)2CO3, catalyzed HAA and NDMA formation. For HAAs, copper catalysis increased with increasing pH from 6.6 to 8.6 and/or increasing concentrations of these copper corrosion products. Interactions of copper with natural organic matter (NOM), likely by complexation, and the subsequent increase in the reactivity of NOM were proposed to be the primary reason for the increased HAA formation.NDMA formation increased with increasing Cu(II) concentrations, DMA concentrations, alkalinity and hardness but was inhibited by the presence of NOM. The transformation of NH2Cl to dichloramine (NHCl2) and complexation of copper with DMA were proposed to be involved in elevating the formation of NDMA at pH 7.0.
Finally, in pilot-scale modified pipe loop tests, copper catalysis of NDMA formation was confirmed, especially under laminar flow conditions, and iron was shown to possibly catalyze NDMA formation under turbulent conditions. Orthophosphate increased the catalytic effects of iron but decreased copper catalysis on NDMA formation by either modifying the properties of the iron-associated suspended particles or reducing the dissolved metal concentrations. Orthophosphate increased chloramine decay when in contact with iron, likely by promoting nitrite formation, but orthophosphate decreased chloramine decay for copper and lead by reducing the availability of metal corrosion products.
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Determinação de ácidos haloacéticos em água utilizando técnicas cromatográficas / DETERMINATION OF ACIDS IN HALOACÉTICOS WATER USING CHROMATOGRAPHIC TECHNIQUESSilva, Claudia Pereira da 18 March 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Disinfection is an essential step in water treatment. This step, in most cases, is made by the use of chlorine and its derivatives, which have been quite effective. However, the use of chlorination to disinfect water produces various
organic substances, among them, haloacetic acids (HAAs), a total of nine species: monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), monobromoacetic acid (MBAA), acid dibromoacetic (DBAA) tribromoacetic acid (TBAA) bromochloroacetic acid (BCAA), bromodichloroacetic acid (BDCA) and dibromochloroacetic acid
(DBCA), which are haloreplaced carboxylic acids, which are toxic to humans, animals and plants. Recent studies have demonstrated an association between the development of some types of cancer with the haloacetic acids. Because of this, the Environmental Protection Agency (EPA) has established for the disinfection by-products a maximum contamination level (MCL) in treated water from 60 μg/L for the sum of five HAAS (MCAA, DCAA, TCAA, MBAA, DBAA ). The World Health Organization (WHO) also established MCL
for DCAA (50 μg/L) and TCAA (100 μg/L). However, Brazil and the European Community do not set limits for these species. Therefore, this study aimed to develop an analytical method for the determination of Haas in water, using chromatographic techniques. Tests chromatographic separations were performed by ion chromatography (IC), high performance liquid
chromatography (HPLC) and gas chromatography (GC) method development for the analysis of haloacetic acids in water. From the tests there were drawbacks in the analysis when it used IC or HPLC. By carrying out analysis by GC, that was with favorable conditions for the analysis, and a prerequisite
for bypass was necessary. When the band worked with 0,5 to 50,0 μg/L were obtained correlation coefficients (r) ranging from 0,98 to 0,99, recoveries in the range 67 to 179%, detection limit of 0,08 to 7,2 μg/L and limit of quantification between 0,2 to 21,6 μg/L for the determination of Haas in
water. / A desinfecção é uma etapa indispensável no tratamento de água. Esta etapa, na grande maioria das vezes, é feita pelo uso do cloro e seus derivados, os quais têm se mostrado bastante eficientes. Entretanto, o uso da cloração para desinfecção de água produz diferentes substâncias
organocloradas, dentre elas, os ácidos haloacéticos (HAAs), em um total de nove espécies: ácido monocloroacético (MCAA), ácido dicloroacético (DCAA), ácido tricloroacético (TCAA), ácido monobromacético (MBAA), ácido dibromoacético (DBAA), ácido tribromoacético (TBAA), ácido
bromocloroacético (BCAA), ácido bromodicloroacético (BDCAA) e ácido dibromocloroacético (DBCAA), que são ácidos carboxílicos halosubstituídos, os quais são tóxicos a seres humanos, animais e plantas. Estudos recentes têm demonstrado a associação entre o desenvolvimento de alguns tipos de câncer com os ácidos haloacéticos. Devido a isto, a Agência de Proteção Ambiental (EPA) tem estabelecido para esses subprodutos de desinfecção um nível de contaminação máximo (MCL) em água tratada de 60μg/L para a soma de cinco HAAs (MCAA, DCAA, TCAA, MBAA, DBAA). A Organização
Mundial de Saúde (WHO) também estabeleceu MCL para DCAA (50μg/L) e TCAA (100μg/L). No entanto, o Brasil e a Comunidade Européia não estabelecem limites para estas espécies. Portanto, o presente trabalho teve como objetivo desenvolver um método analítico para a determinação de
HAAs em água, utilizando técnicas cromatográficas. Testes de separações cromatográficas foram realizados por cromatografia iônica (IC), cromatografia líquida de alta eficiência (HPLC) e cromatografia a gás (GC) para desenvolvimento de método para a determinação dos ácidos
haloacéticos em água. A partir dos testes verificaram-se inconvenientes nas análises quando se usou IC ou HPLC. Ao se proceder a análise por GC, esta se mostrou com condições favoráveis para a análise, sendo que uma etapa prévia de derivação foi necessária. Quando se trabalhou na faixa de
concentração 0,5 a 50 μg/L, obtiveram-se coeficientes de correlação (r) variando de 0,98 0,99, recuperações no intervalo de 67 179%, limite de detecção entre 0,08 7,2 μg/L e limite de quantificação entre 0,2 21,6 μg/L para as determinações dos HAAs em água.
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Effect of drinking water disinfection by-products in human peripheral blood lymphocytes and spermAli, Aftab H.M., Kurzawa-Zegota, Malgorzata, Najafzadeh, Mojgan, Gopalan, Rajendran C., Plewa, M.J., Anderson, Diana 26 August 2014 (has links)
No / Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. OBJECTIVES: To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses.
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