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1.
This work presents an LC–MS–MS-based method for the quantitation of nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) in water, sediment, and suspended particulate matter, and three of their carboxylated derivatives in water. The alkylphenol ethoxylates (APEOs) were analyzed using isotope dilution mass spectrometry with [ 13C 6]-labeled analogues, whereas the carboxylated derivatives were determined by external standard quantitation followed by confirmation using standard additions. The method was used to study APEO’s behavior in a wastewater treatment plant (WWTP), where total dissolved NP0-16EO concentration was reduced by approximately 99% from influent (390 μg l −1) to final effluent (4 μg l −1), and total OP0-5EO concentration decreased by 94% from 3.1 to 0.2 μg l −1. In contrast, the carboxylated derivatives were formed during the process with NP0-1EC concentrations increasing from 1.4 to 24 μg l −1. Short-chain APEOs were present in higher proportions in particulate matter, presumably due to greater affinity for solids compared to the long-chain homologues. NP (0.49 μg l −1) and NP0-1EC (4.8 μg l −1) were the only APEO-related compounds detected in a surface water sample from a WWTP-impacted estuary; implying that 90% of the mass was in the form of carboxylated derivatives. Sediment analysis showed nonylphenol to be the single most abundant compound in sediments from the Baltimore Harbor area, where differences in homologue distribution suggested the presence of treated effluent in some of the sites and non-treated sources in the rest. 相似文献
2.
The present work focuses on the fate of two cancerostatic platinum compounds (CPC), cisplatin and carboplatin, as well as of two inorganic platinum compounds, [PtCl 4] 2− and [PtCl 6] 2− in biological wastewater treatment. Laboratory experiments modelling adsorption of these compounds onto activated sludge showed promising specific adsorption coefficients KD and KOC and Freundlich adsorption isotherms. However, the adsorption properties of the investigated substances were differing significantly. Adsorption decreased following the order cisplatin > [PtCl 6] 2− > [PtCl 4] 2− > carboplatin. Log KD-values were ranging from 2.5 to 4.3 , log KOC from 3.0 to 4.7. A pilot membrane bioreactor system (MBR) was installed in a hospital in Vienna and fed with wastewater from the oncologic in-patient treatment ward to investigate CPC-adsorption in a sewage treatment plant. During three monitoring periods Pt-concentrations were measured in the influent (3–250 μg l−1 Pt) and the effluent (2–150 μg l−1 Pt) of the treatment plant using ICP-MS. The monitoring periods (duration 30 d) revealed elimination efficiencies between 51% and 63% based on averaged weekly input–output budgets. The derived log KD-values and log KOC-values ranged from 2.4 to 4.8 and from 2.8 to 5.3, respectively. Species analysis using HPLC-ICP-MS proofed that mainly carboplatin was present as intact drug in the influent and – due to low log KD – in the effluent of the MBR. 相似文献
3.
Radioisotopes carbon 14 and chlorine 36 were used to elucidate the environmental role of trichloroacetic acid (TCA) formerly taken to be a herbicide and a secondary air pollutant with phytotoxic effects. However, use of 14C-labeling posed again known analytical problems, especially in TCA extraction from the sample matrix. Therefore—after evaluation of available methods—a new procedure using decarboxylation of [1,2- 14C]TCA combined with extraction of the resultant 14C-chloroform with a non-polar solvent and its subsequent radiometric measurement was developed. The method solves previous difficulties and permits an easy determination of amounts between 0.4 and 20 kBq (10–500 ng g −1) of carrier-less [1,2- 14C]TCA in samples from environmental investigations. The procedure is, however, not suitable for direct [ 36Cl]TCA determination in chlorination studies with 36Cl. Because TCA might be microbially degraded in soil during extraction and sample storage and its extraction from soil or needles is never complete, the decarboxylation method—i.e. 2 h TCA decomposition to chloroform and CO 2 in aqueous solution or suspension in closed vial at 90 °C and pH 4.6 with subsequent CHCl 3 extraction—is recommended here, estimated V < 7%. Moreover, the influence of pH and temperature on the decarboxylation of TCA in aqueous solution was studied in a broad range and its environmental relevance is shown in the case of TCA decarboxylation in spruce needles which takes place also at ambient temperatures and might amount more than 10–20% after a growing season. A study of TCA distribution in spruce needles after below-ground uptake shows the highest uptake rate into current needles which have, however, a lower TCA content than older needle-year classes, TCA biodegradation in forest soil leads predominatingly to CO 2. 相似文献
4.
In the present study, a resting cells suspension of Rhodotorula rubra Y-1529 was shown to have the capacity to perform an ortho-dehalogenation reaction on 2-chlorocinnamic acid. The results from the biodegradation of U-[ 14C]benzoic acid, cinnamic acid, 3-chlorocinnamic acid and 4-chlorocinnamic acid suggest that the first step of the ortho-dehalogenation reaction occurred during the oxidation of the unsaturated C3 side chain of 2-chlorocinnamic acid to 2-chlorobenzoic acid. None of the 2-chlorobenzoic acid was found in the biodegradation system, suggesting that this step was a highly regulated step. After the side-chain oxidation reaction, the hydroxylation of the benzene ring was determined to be at the para-position first, followed by the meta-position. The occurrence of 3:4-position ring fission reactions and the production of the final product, CO 2, was proven by the biodegradation of U-[ 14C] benzoic acid. This oxidative dehalogenation reaction catalyzed by R. rubra was found to be regiospecific for 2-chlorocinnamic acid; the chloride ion was probably removed after the ring fission reaction. A pathway of the ortho-dehalogenation reaction of 2-chlorocinnamic acid catalyzed by R. rubra was proposed based on these data. 相似文献
6.
The influence of intact (FLT) and photomodified (phFLT) fluoranthene (0.05, 0.5 and 5 μmol l −1) and herbicide Basagran (5, 20, 35 and 50 nmol l −1) on the germination, growth of seedlings and photosynthetic processes in pea plants ( Pisum sativum L., cv. Garde) was investigated. The germination was significantly inhibited already by the lowest concentration (0.05 μmol l −1) of FLT and phFLT, while Basagran caused inhibition only in higher concentrations (35 and 50 nmol l −1). The growth of roots was significantly inhibited by higher concentration 5 μmol l −1 of both FLT and phFLT and the shoot of seedlings was significantly influenced only by photomodified form. The length of root and shoot was inhibited already by concentration 5 nmol l −1 of Basagran. Organic compounds applied on chloroplasts suspension influenced primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F0 values and the decrease of FV/ FM and ΦII values by application of FLT (0.5 and 5 μmol l −1) and phFLT (0.05, 0.5 and 5 μmol l −1) was recorded. The maximum capacity of PSII ( FV/ FM) was influenced by the highest (50 nmol l −1) and the effective quantum yield of PSII ( ΦII) already by the lowest (5 nmol l −1) concentration of Basagran. Hill reaction activity decreased and was significantly inhibited by higher concentration (0.5 and 5 μmol l −1) of FLT and phFLT and already by the lowest concentration (5 nmol l −1) of Basagran. 相似文献
7.
13C CP-MAS NMR spectroscopy is a technique that has proved to be useful in studying soil organic matter (SOM). Nevertheless, NMR spectra exhibit a weak signal and have very low resolution due to: the low natural abundance of 13C (1.1 % of C) in SOM, the generally low SOM content of soils, and the presence of paramagnetic impurities. This paper studies the effects of soil chemical pre-treatments on 13CP-MAS NMR spectra quality and spectra representativity i.e. soil C mass balance. After chemical pre-treatment to increase total organic carbon (TOC) content and C/Fe ratio, eight soils characterized by different levels of organic carbon content and C/Fe ratios were studied using 13CP-MAS NMR. Moreover, where chemical treatments were not applicable due to high carbon losses, the number of 13CP-MAS NMR scans was increased in order to obtain satisfactory spectra. Results show that chemical pre-treatment of soils with C/Fe > 1 caused high C losses. Bulk soils were therefore studied by increasing the number of 13CP-MAS NMR scans. Acceptable spectra were obtained from 8K scans (1K = 1024 transient). On the other hand, even when a large number of scan (32K) are used, soil with C/Fe < 1 cannot be studied. As these soils are characterized by low C losses after HCl treatments (range of 2.9–25.4%), a pre-treatment of at least 1.39 mol l−1 HCl removes excess Fe and at the same time increases C/Fe ratio resulting in 32K scans providing good spectra. 相似文献
8.
The characterization of the Chlorella vulgaris solution was carried out using synchronous-scan spectroscopy. The range of concentration of algae and Fe(III) in aqueous solutions were 5 × 10 8–8 × 10 9 cells l −1 and 10–60 μM, respectively. Effective characterization method used was synchronous-scan fluorescence spectroscopy. The wavelength difference (Δ λ) of 90 nm was maintained between excitation and emission wavelengths; 90 nm was found to be the best Δ λ for effective characterization of Chlorella vulgaris solution with or without quencher species (e.g., Fe(III), humic acid (HA)) for the first time. The peak was observed at about EX 236.6 nm/EM 326.6 nm for synchronous-scan fluorescence spectra. The fluorescence quenching of algae in system of algae–Fe(III)–HA was studied using synchronous-scan spectroscopy for the first time. Fe(III) was clearly the effective quencher. The relationship between I0/ I (quenching efficiency) and c (concentration of Fe(III) added) was a linear correlation for the algae solution with Fe(III). Also, Aldrich humic acid was found to be an effective quencher. pH effect on synchronous-scan fluorescence intensity of algal solution with Fe(III) and/or HA was evident. 相似文献
9.
The leachability of polycyclic aromatic hydrocarbons from coal ash into aqueous systems was studied. Carbon-14-labeled 3,4-Benzopyrene (BaP) was deposited on coal fly ash by adsorption from the liquid phase in quantities of about 10 μg/g ash. After a thermal treatment in air at 120 °C for 2 hours the desorption of BaP was measured using aqueous solutions of acetone and methanol as extractants and liquid scintillation counting as detection method. In all cases the 14C-recovery was incomplete. Using water as extractant, 14C-recoveries of about 1 % were found. In the presence of a non-ionic surface active agent (Tween 80) the 14C-recovery was enhanced significantly. For these reasons further experiments under realistic waste disposal conditions are necessary. 相似文献
10.
13C12-Labelled mono-, di-, and tri-chlorinated dibenzo-p-dioxin (CDD) and chlorinated dibenzofuran (CDF) standards have been tested for their applicability to standard EPA sampling and analytical Methods 0023A/8290. These methods target for analysis only the tetra- through octa-CDD/CDF homologues. Extension of the isotope dilution method to include those lower chlorinated homologues is important toward obtaining reliable species concentration data on the complete, mono- to octa-chlorinated homologue profile. These data will improve our ability to model poly-CDD/CDF concentrations through understanding mechanisms of poly-CDD/CDF formation, chlorination, and dechlorination. 相似文献
11.
We have investigated the capacity of various indoles to inhibit specific binding of [1,6- 3H]2,3,7,8-tetrachlorodibenzo-
-dioxin ([ 3H]TCDD) in rat liver cytosol, as analyzed by electrofocusing in polyacrylamide gels. Of these indoles, indolo[3,2-
]carbazole was the most active. The IC 50 value for TCDD receptor binding of indolo[3,2-
]carbazole as well as for 2,3,7,8-tetrachlorodibenzofuran was 3.6 nM. We have also studied the influence on binding exerted by introduction of some substituents on indolo[3,2-
]carbazole. Substitution with methyl groups at the 5 and 11 positions resulted in an increased affinity (IC 50 1.2 nM) for the TCDD receptor as compared to the parent compound. Computer-supported molecular structure studies indicated that if the van der Waals radii of atoms are included, a rectangle of 6.8 × 13.7 Å may account for the binding of high-affinity ligands to the TCDD receptor. 相似文献
12.
Cyanogen chloride was formed by the reactions of purine bases(adenine and guanine) with hypochlorous acid in the presence of ammonium ion. The origin of the carbon and nitrogen atoms of cyanogen chloride formed from adenine was investigated by use of synthetic adenines variously labeled with the isotope of nitrogen( 15N) or carbon( 13C). 相似文献
13.
DDT and benzo[a]pyrene (BaP) were added both separately and as a mixture to filtered (0.22 μm) humic surface water samples. Following a contact time of 1 d, the fraction bound to dissolved organic matter and the freely dissolved part were separated by using reversed-phase octadecyl silica cartridges. The enriched solutes were analysed by gas chromatography-mass spectrometry in the selective ion monitoring (GC-MS/SIM) mode. Partition coefficients to dissolved organic matter, calculated on the basis of the recovery data, varied between 2.0 × 10 4 and 6.6 × 10 4 mL/g for BaP depending on the experimental conditions, whereas the corresponding values for DDT (0.6 × 10 4 mL/g) showed no significant variation. 相似文献
14.
This study aimed to investigate the persistence of imidacloprid in soil after application to cotton seeds and to obtain a complete picture on the mass balance of this compound in soil and cotton plants. The study was carried out as a pot culture experiment under laboratory conditions using a Gaucho formulation containing 14C-labeled imidacloprid. Three treatments of cotton seeds were made in sandy loamy soil: live seeds grown in autoclaved soil, dead seeds put in live soil and live seeds grown in live soil. Results showed that total 14C recoveries decreased by time ranging 93.8–96.2, 77.1–88.4 and 53.5–62.4% of the applied radioactivity at 7, 14, and 21 d after application, respectively. The reduction in the extracted 14C from soil coincided with the increase of non-extracted ones. Levels of bound 14C was always less in autoclaved soil than in live ones. Results revealed also that only 1.8–6.8% of the applied 14C was taken up by the plants and fluctuated within the test period. 14C levels were higher in plants grown in autoclaved soil than those in live ones and the radioactivity tended to accumulate on the edges of cotton leaves. Most of the radioactivity in the soil extracts was identified as unchanged 14C-imidacloprid. 相似文献
15.
The use of nuclear magnetic resonance chemical shift data for predicting the rate of photodegradation of organic chemicals in air, due to reaction with hydroxyl radicals, has been critically examined. Relationships between the average 13C or 1H chemical shift and the hydroxyl radical rate constant have been studied for a wide range of compounds. Recommendations regarding the utility of the procedure are made. 相似文献
16.
The photocatalytic inactivation (PCI) of Escherichia coli (Gram-negative) and Bacillus subtilis (Gram-positive) was performed using polyoxometalate (POM) as a homogeneous photocatalyst and compared with that of heterogeneous TiO 2 photocatalyst. Aqueous suspensions of the microorganisms (10 7–10 8 cfu ml −1) and POM (or TiO 2) were irradiated with black light lamps. The POM-PCI was faster than (or comparable to) TiO 2-PCI under the experimental conditions employed in this study. The relative efficiency of POM-PCI was species-dependent. Among three POMs (H 3PW 12O 40, H 3PMo 12O 40, and H 4SiW 12O 40) tested in this study, the inactivation of E. coli was fastest with H 4SiW 12O 40 while that of B. subtilis was the most efficient with H 3PW 12O 40. Although the biocidal action of TiO 2 photocatalyst has been commonly ascribed to the role of photogenerated reactive oxygen species such as hydroxyl radicals and superoxides, the cell death mechanism with POM seems to be different from TiO 2-PCI. While TiO 2 caused the cell membrane disruption, POM did not induce the cell lysis. When methanol was added to the POM solution, not only the PCI of E. coli was enhanced (contrary to the case of TiO 2-PCI) but also the dark inactivation was observed. This was ascribed to the in situ production of formaldehyde from the oxidation of methanol. The interesting biocidal property of POM photocatalyst might be utilized as a potential disinfectant technology. 相似文献
17.
This study shows the important role of humic acids in the degradation of 14C and 13C labeled isomer of NP by Sphingomonas sp. strain TTNP3 and the detoxification of the resulting metabolites. Due to the association of NP with humic acids, its solubility in the medium was enhanced and the extent of mineralization of nonylphenol increased from 20% to above 35%. This was accompanied by the formation of significant amounts of NP residues bound to the humic acids, which also occurred via abiotic reactions of the major NP metabolite hydroquinone with the humic acids. Gel permeation chromatography showed a non-homogenous distribution of NP residues with humic acids molecules, with preference towards molecules with high-molecular-weight. Solid state 13C nuclear magnetic resonance spectroscopy indicated that the nonextractable residues resulted exclusively from the metabolites. The chemical shifts of the labeled carbon indicated the possible covalent binding of hydroquinone to the humic acids via ester and possibly ether bonds, and the incorporation of degradation products of hydroquinone into the humic acids. This study provided evidences for the mediatory role of humic acids in the fate of NP as a sink for bacterial degradation intermediates of this compound. 相似文献
18.
This study investigated the effect of chemical heterogeneity of humic acids (HAs) on the equilibrium sorption of phenanthrene by HA extracts. Six HA samples were extracted from three different soils with 0.5 M NaOH and 0.1 M Na 4P 2O 7 and were characterized with elemental analysis, infrared spectrometry, and solid-state 13C nuclear magnetic resonance (NMR) spectrometry. The equilibrium sorption measurements were carried out with a batch technique and using the six HA solids as the sorbents and phenanthrene as the sorbate. The measured sorption isotherm data were fitted to the Freundlich equation. The results showed that, for the same soil, (i) the total HA mass extracted with Na 4P 2O 7 was 13.7–22.6% less than that extracted with NaOH, (ii) the Na 4P 2O 7-extracted HA had higher O/C atomic ratio, greater content of polar organic carbons (POC), and lower aliphatic carbon content than the NaOH-extracted HA, and (iii) the Na 4P 2O 7-extracted HA exhibited greater sorption isotherm linearity and but not dramatic difference in sorption capacities than the NaOH extracted HA. The differences in the HA properties resulting from the two different extraction methods may be because NaOH can hydrolyze insoluble HA fractions such as fatty acid like macromolecules bound on soils whereas Na 4P 2O 7 could not. As a result, the HAs extracted with the two different methods had different polarity and functionality which affected their sorption property for phenanthrene. 相似文献
19.
A loamy clay soil containing unextractable 14C-ring labeled atrazine residues was incubated in microcosms under abiotic and biotic conditions. The mineralization activity of the soil microflora was evaluated by the release of total CO 2 and 14C0 2. After 63 days of sample incubation the total organic carbon mineralization was of 1.71%, that of 14C-residues was of 0.72% of the initial radioactivity. No direct relationship was established between the mineralization of atrazine residues and the global mineralization. The contribution of soil microorganisms in the release of 14C-residues was weak. The availability of non-extractable residues was mainly controlled by physico-chemical factors. The low value of the reextractability rate and the distribution of bound residues during the soil sample incubation shown the active role of organic matter in detoxification procedure. Ninety percent of the residues remained bound after 63 days of incubation and were thus, potentially available without biocide activity. The fractionation of soil organic matter allowed to specify the distribution of bound residues within the organic compartments. After a long-stay of pesticides in soils, approximately 65% of bound residues were associated with humin. 相似文献
20.
The binding of three polychlorinated biphenyl (PCB) congeners to natural levels of dissolved organic carbon (DOC) was measured in 12 lakes and streams using Sep-Pak C 18 columns. The association coefficients calculated on the basis of DOC (i.e. K DOC mL/g C), varied by over an order of magnitude among the different freshwaters and ranged between 2.05 × 10 2 and 8.86 × 10 3 mL/g C for PCB 52 and 1.03 × 10 4 and 1.70 × 10 5 mL/g C for PCB 153. In general, there were no significant correlations (p > 0.05) between the K DOC values and various chemical parameters in the study lakes and streams. A relationship was derived between the fraction of bound PCB and the octanol-water partition coefficient. While this relationship explained almost 50% of the variation in the observed data, it is apparent that other factors influence KDOC values and that in natural freshwaters, only a small fraction of the DOC is involved in the binding of PCBs and other hydrophobic pollutants. 相似文献
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