Formation of HAAs during Chlorination of Aspartic Acid in Drinking Water

2011 ◽  
Vol 250-253 ◽  
pp. 3425-3428 ◽  
Author(s):  
Zhong Lin Chen ◽  
An Li ◽  
Sheng Jun Wang ◽  
Ying Han ◽  
Feng Liu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Reaction Time ◽  
Aspartic Acid ◽  
Trichloroacetic Acid ◽  
Initial Period ◽  
Dichloroacetic Acid ◽  
Haloacetic Acids ◽  
Chlorination Process ◽  
Alkaline Conditions ◽  
By Products

As a traditional disinfection method, chlorination disinfection is used generally in the plants ,however, disinfection by-products (DBPs) during chlorination process generate accordingly. Nitrogenous organic compounds is a kind of important precursors of DBPs. Haloacetic acids (HAAs) is one kind of the main DBPs. Aspartic acid (Asp) is one kind of elementary amino acids,which are typical nitrogenous organic compounds.In this paper, the formation characteristics of HAAs by Asp under different chlorination disinfection conditions have been researched, such as reaction time, chlorine dosage, pH, temperature and Br- . The results show that the yields of dichloroacetic acid(DCAA) and trichloroacetic acid(TCAA) are both increased with the reaction time increasing,and the formation rates is accelerated at the initial period; With the increase of chlorine dosage, the yields of DCAA and TCAA increased; The yield of DCAA and TCAA are both low in the acidic condition and high in the conditions of neutral and alkaline conditions. The yield of DCAA and TCAA increased with the increase of temperature. When there is Br- in water, bromided-HAAs can be formed.The total HAAs yield and BIF both increase with the increase of Br- concentration. The HAAs constituents contain DCAA,TCAA,BCAA,DBCAA, DCBAA, DBAA and TBAA. At low Br- concentration,the order of HAAs constituents yields is DCAA>BCAA>DCBAA>TCAA>DBCAA> DBAA>TBAA.

scholarly journals Exposure to disinfectant by-products and the risk of stillbirth in Massachusetts

2018 ◽  
Vol 75 (10) ◽  
pp. 742-751 ◽  
Author(s):  
Zorimar Rivera-Núñez ◽  
J Michael Wright ◽  
Amy Meyer
Keyword(s):  
Drinking Water ◽  
Trichloroacetic Acid ◽  
Dichloroacetic Acid ◽  
Haloacetic Acids ◽  
Future Research ◽  
Second Trimester ◽  
Exposure Response ◽  
Exposure Metrics ◽  
Monobromoacetic Acid ◽  
By Products

ObjectivesWe examined stillbirths in relation to disinfection by-product (DBP) exposures including chloroform, bromodichloromethane (BDCM), dibromochloromethane, bromoform, trichloroacetic acid, dichloroacetic acid (DCAA), monobromoacetic acid and summary DBP measures (trihalomethanes (THM4), haloacetic acids (HAA5), THMBr (brominated trihalomethanes) and DBP9 (sum of THM4 and HAA5)).MethodsWe randomly selected 10 controls for each of the 2460 stillbirth cases with complete quarterly 1997–2004 THM4 and HAA5 town-level drinking water data. Adjusted (aORs) were calculated based on weight-averaged second-trimester DBP exposures.ResultsWe detected statistically significant associations for stillbirths and the upper DCAA quartiles (aOR range: 1.50–1.71). We also found positive associations for the upper four HAA5 quintiles and different stillbirth cause of death categories that were examined including unexplained stillbirth (aOR range: 1.24–1.72), compression of umbilical cord (aOR range: 1.08–1.94), prematurity (aOR range: 1.37–2.88), placental separation and haemorrhage (aOR range: 1.44–2.01) and asphyxia/hypoxia (aOR range: 1.52–1.97). Additionally, we found positive associations between stillbirths and chloroform exposure (aOR range: 1.29 – 1.36) and unexplained stillbirths and BDCM exposure (aOR range: 1.51 – 1.78). We saw no evidence of exposure–response relationships for any categorical DBP metrics.ConclusionsConsistent with some previous studies, we found associations between stillbirths and chloroform and unexplained stillbirth and BDCM exposures. These findings strengthen existing evidence of prenatal THM exposures increasing the risk of stillbirth. Additionally, we saw statistically significant associations between DCAA and stillbirth. Future research should examine cause-specific stillbirths in relation to narrower critical windows and additional DBP exposure metrics beyond trihalomethanes and haloacetic acids.

scholarly journals Biodegradation of six haloacetic acids in drinking water

2007 ◽  
Vol 6 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Walt Bayless ◽  
Robert C. Andrews
Keyword(s):  
Drinking Water ◽  
Trichloroacetic Acid ◽  
Distribution Systems ◽  
Water Distribution ◽  
Haloacetic Acids ◽  
Health Concern ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Monobromoacetic Acid ◽  
By Products

Haloacetic acids (HAAs) are produced by the reaction of chlorine with natural organic matter and are regulated disinfection by-products of health concern. Biofilms in drinking water distribution systems and in filter beds have been associated with the removal of some HAAs, however the removal of all six routinely monitored species (HAA6) has not been previously reported. In this study, bench-scale glass bead columns were used to investigate the ability of a drinking water biofilm to degrade HAA6. Monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA) were the most readily degraded of the halogenated acetic acids. Trichloroacetic acid (TCAA) was not removed biologically when examined at a 90% confidence level. In general, di-halogenated species were removed to a lesser extent than the mono-halogenated compounds. The order of biodegradability by the biofilm was found to be monobromo > monochloro > bromochloro > dichloro > dibromo > trichloroacetic acid.

scholarly journals Occurrence of Free d-Amino Acids and Aspartate Racemases in Hyperthermophilic Archaea

1999 ◽  
Vol 181 (20) ◽  
pp. 6560-6563 ◽  
Author(s):  
Megumi Matsumoto ◽  
Hiroshi Homma ◽  
Zhiqun Long ◽  
Kazuhiro Imai ◽  
Toshii Iida ◽  
...  
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Hyperthermophilic Archaea ◽  
Homologous Genes ◽  
Aspartate Racemase ◽  
Crude Extracts ◽  
By Products

ABSTRACT The occurrence of free d-amino acids and aspartate racemases in several hyperthermophilic archaea was investigated. Aspartic acid in all the hyperthermophilic archaea was highly racemized. The ratio of d-aspartic acid to total aspartic acid was in the range of 43.0 to 49.1%. The crude extracts of the hyperthermophiles exhibited aspartate racemase activity at 70°C, and aspartate racemase homologous genes in them were identified by PCR.d-Enantiomers of other amino acids (alanine, leucine, phenylalanine, and lysine) in Thermococcus strains were also detected. Some of them might be by-products of aspartate racemase. It is proven that d-amino acids are produced in some hyperthermophilic archaea, although their function is unknown.

scholarly journals Photooxidation of atrazine and its influence on disinfection byproducts formation during post-chlorination: effect of solution pH and mechanism

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yucan Liu ◽  
Kai Zhu ◽  
Huayu Zhu ◽  
Min Zhao ◽  
Lihua Huang ◽  
...  
Keyword(s):  
Trichloroacetic Acid ◽  
Irradiation Time ◽  
Disinfection Byproducts ◽  
Dichloroacetic Acid ◽  
Solution Ph ◽  
Chlorination Process ◽  
Process System ◽  
Uv Lamps ◽  
The Impact ◽  
Degradation Intermediates

AbstractPartial photooxidation of micropollutants may lead to various degradation intermediates, obviously affecting disinfection byproducts (DBPs) formation during the post-chlorination process. The photooxidation of atrazine (ATZ) in aqueous solutions with low-pressure mercury UV lamps in UV, UV/H2O2 and UV/TiO2 treatment system and the formation of chlorinated disinfection byproducts (DBPs) during subsequent chlorination processes including dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), 1,1,1-trichloro-2-propanone (TCP), trichloromethane (TCM) and chloropicrin (CHP) were investigated in this study. The effect of solution pH on the oxidation pathway of ATZ in three UV photooxidation treatment process and the impact of photooxidation on the DBPs formations were assessed. Based on UPLC-ESI–MS/MS analyses, identification of main oxidation intermediates was performed and the plausible degradation pathways of ATZ in photooxidation system were proposed, indicating that photooxidation of ATZ in UV/H2O2 and UV/TiO2 process system was significantly pH-dependent processes. Dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), 1,1,1-trichloro-2-propanone (TCP), trichloromethane (TCM) and chloropicrin (CHP) were detected in photooxidized ATZ solutions. Compared to the other three DBPs, TCM and TCP were the main DBPs formed. The DBPs formations were greatly promoted in oxidized ATZ solutions. Solution pH and UV irradiation time exhibited obvious impact on the DBPs formation on the basis of DBP species. The variation tendency of DBPs observed relates to the combustion of ATZ in photooxidation system and the production oxidation intermediates.

Quantifying the formation of nitrogen-containing disinfection by-products in chlorinated water using absorbance and fluorescence indexes

2011 ◽  
Vol 63 (1) ◽  
pp. 40-44 ◽  
Author(s):  
P. Roccaro ◽  
F. G. A. Vagliasindi ◽  
G. V. Korshin
Keyword(s):  
Organic Matter ◽  
Reaction Time ◽  
Real Time ◽  
Natural Organic Matter ◽  
Haloacetic Acids ◽  
Real Time Monitoring ◽  
Potential Toxicity ◽  
Reaction Conditions ◽  
Drinking Waters ◽  
By Products

Among known but unregulated disinfection by-products (DBPs), several nitrogenous species (N-DBPs) have been found in drinking waters. While concentrations of N-DBP are much lower than those of trihalomethanes (THMs) and haloacetic acids (HAAs), their potential toxicity is higher. In this study the relationships between the formation of N-DBPs and the changes in NOM caused by the chlorination of raw Ancipa water quantified by the use of differential absorbance and fluorescence indexes were investigated. Very strong relationships were found between selected N-DBPs (i.e. trichloronitromethane and dichloroacetonitrile) and the proposed spectroscopic indexes that were previously developed to quantify the changes in natural organic matter (NOM) during chlorination at varying reaction conditions (chlorine dose, reaction time and temperature) and the generation of DBPs. Obtained results clearly indicate that the changes in NOM absorbance and fluorescence are fundamental descriptors of the formation of both commonly controlled halogenated DBPs and N-DBPs. This approach may be suitable for real time monitoring of emerging N-DBPs and for studying their formation pathways.

The Evaluation of Genotoxicity Using DNA Repairing Test for Chemicals Produced in Chlorination and Ozonation Processes

1991 ◽  
Vol 23 (1-3) ◽  
pp. 329-338 ◽  
Author(s):  
Yoshiro Ono ◽  
Isao Somiya ◽  
Masasumi Kawamura
Keyword(s):  
Dna Repair ◽  
Organic Compounds ◽  
Quantitative Evaluation ◽  
Trichloroacetic Acid ◽  
Research Work ◽  
Dichloroacetic Acid ◽  
Umu Test ◽  
Organic Halogenated Compounds ◽  
By Products ◽  
Microsomal Activation

The umu-test which can detect the induction of DNA repair is applied in order to analyze the genotoxicity of by-products of chlorination and ozonation. In this research work, the genotoxicities of 37 comnercial chemicals which are expected to be involved in the by-products of chlorination and ozonation processes are checked and evaluated by the umu-test. The genotoxicities of the following organic halogenated compounds are clearly detected: Without microsomal activation; m-dichlorobenzene, 1,2,4-trichlorobenzene and bromoform: With microsomal activation; m-dichlorobenzene, dichloroacetic acid, trichloroacetic acid and chloral are detected. From the results on some compounds which are expected to be produced by ozonation, formaldehyde and ionone show positive genotoxicities without microsomal activation, and 5 compounds have positive genotoxicities with microsomal activation; formaldehyde, furfrol, carvone, glyoxal and acrolein. The effects of the concentration on genotoxicities of those chemicals are discussed and compared with the results obtained in other bacterial assays. Some of the selected organic compounds, chloroform and so on, are identified positive genotoxic, which were reported not to be mutagenic in other bacterial assays. As the Quantitative evaluation for genotoxicity on chemical dose, the time of DNA repairing on damaged spots by SOS genes and the induction rate of umu gene are experimentally evaluated.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Enzymatic Synthesis of 15N-L-aspartic Acid Using Recombinant Aspartase from Escherichia Coli K12

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Iulia Lupan ◽  
Sergiu Chira ◽  
Maria Chiriac ◽  
Nicolae Palibroda ◽  
Octavian Popescu
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Enzymatic Synthesis ◽  
Large Scale ◽  
Recombinant Dna ◽  
Industrial Enzymes ◽  
Recombinant Dna Technology ◽  
Bacterial Fermentation ◽  
Natural Protein ◽  
Novel Method

Amino acids are obtained by bacterial fermentation, extraction from natural protein or enzymatic synthesis from specific substrates. With the introduction of recombinant DNA technology, it has become possible to apply more rational approaches to enzymatic synthesis of amino acids. Aspartase (L-aspartate ammonia-lyase) catalyzes the reversible deamination of L-aspartic acid to yield fumaric acid and ammonia. It is one of the most important industrial enzymes used to produce L-aspartic acid on a large scale. Here we described a novel method for [15N] L-aspartic synthesis from fumarate and ammonia (15NH4Cl) using a recombinant aspartase.

Post-proline endopeptidase, further characterization of the enzyme from pig kidneys

1984 ◽  
Vol 49 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
Karel Hauzer ◽  
Tomislav Barth ◽  
Linda Servítová ◽  
Karel Jošt
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Relative Molecular Mass ◽  
Enzyme Molecule ◽  
Thiol Compounds ◽  
Modified Method ◽  
N Terminus

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.

scholarly journals Enzymatic Preparation of Bioactive Peptides Exhibiting ACE Inhibitory Activity from Soybean and Velvet Bean: A Systematic Review

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3822
Author(s):  
Azis Boing Sitanggang ◽  
Jessica Eka Putri ◽  
Nurheni Palupi ◽  
Emmanuel Hatzakis ◽  
Elvira Syamsir ◽  
...  
Keyword(s):  
Systematic Review ◽  
Amino Acids ◽  
Reaction Time ◽  
Hydrolytic Activity ◽  
Converting Enzyme ◽  
Enzymatic Preparation ◽  
Angiotensin I ◽  
Velvet Bean ◽  
Angiotensin I Converting Enzyme ◽  
Aspergillus Sp

The Angiotensin-I-converting enzyme (ACE) is a peptidase with a significant role in the regulation of blood pressure. Within this work, a systematic review on the enzymatic preparation of Angiotensin-I-Converting Enzyme inhibitory (ACEi) peptides is presented. The systematic review is conducted by following PRISMA guidelines. Soybeans and velvet beans are known to have high protein contents that make them suitable as sources of parent proteins for the production of ACEi peptides. Endopeptidase is commonly used in the preparation of soybean-based ACEi peptides, whereas for velvet bean, a combination of both endo- and exopeptidase is frequently used. Soybean glycinin is the preferred substrate for the preparation of ACEi peptides. It contains proline as one of its major amino acids, which exhibits a potent significance in inhibiting ACE. The best enzymatic treatments for producing ACEi peptides from soybean are as follows: proteolytic activity by Protease P (Amano-P from Aspergillus sp.), a temperature of 37 °C, a reaction time of 18 h, pH 8.2, and an E/S ratio of 2%. On the other hand, the best enzymatic conditions for producing peptide hydrolysates with high ACEi activity are through sequential hydrolytic activity by the combination of pepsin-pancreatic, an E/S ratio for each enzyme is 10%, the temperature and reaction time for each proteolysis are 37 °C and 0.74 h, respectively, pH for pepsin is 2.0, whereas for pancreatin it is 7.0. As an underutilized pulse, the studies on the enzymatic hydrolysis of velvet bean proteins in producing ACEi peptides are limited. Conclusively, the activity of soybean-based ACEi peptides is found to depend on their molecular sizes, the amino acid residues, and positions. Hydrophobic amino acids with nonpolar side chains, positively charged, branched, and cyclic or aromatic residues are generally preferred for ACEi peptides.

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