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1.
Water solubilities (SW) determined by the HPLC generator column method are reported for a series of chlorinated dibenzo-p-dioxins (PCDDs) with SW ranging from 0.4 ng/L (ppt) for octa-chlorodibenzo-p-dioxin to 430 ng/L for 1,2,3,7-tetrachlorodibenzo-p-dioxin at 20°C. A correlation is demonstrated between SW and HPLC capacity factors (k′) for these extremely hydrophobic compounds, allowing calculation of SW of PCDDs from k′ and melting point data.  相似文献   

2.
This paper reports the bioaccumulation of three PCBs (2,4′-dichlorobiphenyl, 2,4,6,2′-tetrachlorobiphenyl and 2,4,6,2′,4′-pentachlorobiphenyl) by the green alga Chlorellafusca under various conditions. A probable pattern of the bioconcentration mechanism is suggested. No metabolites were extracted from algae or water 6 days after incubation with PCBs.  相似文献   

3.
MR Cull  AJ Dobbs 《Chemosphere》1984,13(9):1091-1099
Wood samples treated with technical pentachlorophenol (PCP), technical sodium pentachlorophenoxide (NaPCP) and octachlorodibenzo-p-dioxin have been exposed outdoors for periods up to 212 years. Analysis of extracts from the samples show that photolytic reductive dechlorination of highly chlorinated dibenzo-p-dioxins to less chlorinated isomers occurs. However there is no discernible increase in polychlorodibenzo-p-dioxin concentrations in the technical PCP treated wood presumably because further photolytic reactions and volatilisation compete effectively with the photolytic formation. There is no evidence for formation of octachlorodibenzo-p-dioxin (OCDD) in technical PCP treated wood in this study, probably because photolytic destruction and volatilisation compete effectively with formation reactions when the initial OCDD concentration is relatively high.  相似文献   

4.
J.H. Canton  W. Slooff 《Chemosphere》1982,11(9):891-907
The toxicity of nitrolotriacetic acid (NTA), citrex-S-5, sodium alluminium silicate (NAS), carboxymethyloxysuccinate (CMOS), linear alkylbenzene sulfonate (LAS) and soap was examined using bacteria (Pseudomonasfluorescens), algae (Chlorellavulgaris and Microcystisaeruginosa), crustaceans (Daphniamagna), insects (Aedesaegypti), fishes (Poeciliareticulata and Oryziaslatipes) and amphibians (Xenopuslaevis). The biodegradability of NTA, citrex-S-5, CMOS and LAS was studied in the OECD-test.The acute toxicity of the compounds differed largely with the organisms tested (up to a factor 1,000). Based on the results of the short-term toxicity tests (with all test organisms) and the long-term toxicity tests (with Daphniamagna and in case of LAS also with Poeciliareticulata) the following no-observed-effect concentrations (NOEC) could be derived: LAS 3.2 mg/1; NAS and soap 10 mg/1; CMOS 32 mg/1; NTA 100 mg/1 and citrex-S-5 320 mg/1. However, testing different samples of one test compound may result in marked differences in toxicity (e.g. NAS: a factor 32).All compounds tested showed to be biodegradable as the percentage DOC decreased more than 80% within four weeks. CMOS biodegraded quickly, whereas citrex-S-5 and LAS showed a somewhat slower rate of degradation. In contrast to the other compounds NTA required an adaptation period of 1 week.  相似文献   

5.
William M. Draper 《Chemosphere》1985,14(9):1195-1203
The present study describes a procedure for determination of an average quantum yield for the wavelength range of 310 to 410 nm. Solutions of the pollutant in sealed Pyrex tubes are irradiated in a Rayonet photoreactor fitted with fluorescent lamps emitting maximally at 355 nm. The integrated spectral overlap and the photolysis half-life for both the chemical actinometer and the pollutant are determined and from these data the quantum yield is calculated. The method has been evaluated by measuring quantum yields for organophosphorus, chlorinated hydrocarbon, and dinitroaniline pesticides and p-nitroanisole/pyridine mixtures. Corrected quantum yields are obtained on simultaneous irradiation of the trifluralin actinometer.  相似文献   

6.
The preparation of 14C-labelled biphenyl, 2,5-dichlorobiphenyl, 2,4′,5-trichlorobiphenyl, 2,2′,4,5′-tetrachlorobiphenyl, 2′,3,4,4′,5-pentachlorobiphenyl, 2,2′,3,4,4′-pentachlorobiphenyl, 2,3,3′,4′,6-pentachlorobiphenyl and 2,2′,3,3′,6-pentachlorobiphenyl is described [14C]Aniline hydrogen sulfate used as a starting material was acetylated, chlorinated and deacetylated followed by coupling to benzene or an appropriate chlorobenzene to give the biphenyls labelled in the phenyl nuclei having chlorine atoms at the 4-, 2,4- or 2,3,6-positions, respectively. The structures of the labelled compounds were established by comparison with authentic samples among which 2′,3,4,4′,5- and 2,2′,3,4,4′-pentachlorobiphenyl were not earlier described.A simple method for the preparation of 2,3,6-trichloroacetanilide, unlabelled and labelled, was worked out. 2,6-Dichloroacetanilide in concentrated hydrochloric acid gave the meta substituted product when treated with chlorine.An improved thin layer chromatographic technique utilizing plates impregnated with certain tetraalkylammonium salts was used for separation of some of the labelled compounds prepared.  相似文献   

7.
The LC50 values of eight triorganotin compounds for crab zoeae, Rhithropanopeusharrisii correlate with substituent constants reflecting partitioning effects. Computed molar surface areas predict toxicity as well as any parameter used suggesting that partitioning into lipids controls the toxicity.  相似文献   

8.
The activities of several commercial PCB mixtures as inducers of microsomal aryl hydroarbon hydroxylase (AHH) and ethoxyresorufin 0-deethylase (EROD) in male Wistar rats and rat hepatoma cells were dependent on the chlorine content (and congener distribution) of the mixtures. The was a correlation between the in vivo and in vitro induction potencies of these mixtures; the most active mixtures, Aroclors 1242, 1248 and 1254 contained 42–54% by weight of Cl whereas formulations with higher or lower (Aroclors 1221 and 1268 respectively) chlorine content exhibited lower activities. This corresponds with studies reported for PCB isomers and congeners in which the most active compounds are tetra-hexachlorobiphenyls.  相似文献   

9.
Uptake, clearance and extent of metabolism of 14C-labelled t-butylphenyldiphenyl phosphate (t-BPDP), tri-m-cresyl phosphate (mTCP), tri-p-cresyl phosphate (pTCP) and triphenyl phosphate (TPP) were studied in rainbow trout (Salmogairdneri) and fathead minnows (Pimephalespromelas) using short-term static exposures (50 and 5 μmg/L). Bioconcentration factors for pTCP, mTCP, TPP and tBPDP calculated by use of total radioactivity in whole fish were 1420, 784, 573 and 1096 respectively, for rainbow trout and 928, 596, 561 and 1010 respectively, for fathead minnows. Differences in rates of clearance and biotransformation among the four compounds were more closely related to their ease of hydrolysis than to hydrophobicity.  相似文献   

10.
Weddell seal samples taken from the Antarctic have been found to be contaminated with chlordane compounds. ΣChlordane (cis-chlordane + cis-nonachlor + trans-nonachlor + oxychlordane) was present in blubber of seals at the range of 12 - 62 ng/g fresh weight. The order of chlordane compound concentrations was trans-nonachlor >oxychlordane >cis-nonachlor >cis-chlordane. Relative aboundance of cis-chlordane in Σchlordane is higher than that in humans. A probable explanation for their occurrence in the Antarctic is an airborne transport.  相似文献   

11.
Biofiltration is cost-effective for the treatment of gases containing low concentrations of volatile organic compounds (<3gm−3). However, conventional biofilters, based on compost and bacterial activity, face problems with the elimination of hydrophobic compounds. Besides that, biofilter operational stability is often hampered by acidification and drying out of the filter bed. To overcome these problems, biofilters with fungi on inert packing material have been developed. Fungi are more resistant to acid and dry conditions than bacteria, and it is hypothesised that the aerial mycelia of fungi, which are in direct contact with the gas, can take up hydrophobic compounds faster than flat aqueous bacterial biofilm surfaces. Alpha-pinene was chosen as a model compound. It is an odorous compound emitted by the wood processing industry. In 2l biofilter columns four different packing materials were tested: perlite, expanded clay granules, polyurethane foam cubes and compost. The filters were inoculated with forest soil and ventilated with gas containing alpha-pinene. Start up took 1–2 months and removal efficiencies of more than 90% were observed, but mostly ranged from 50% to 90% due to overloading. In the filters containing perlite, clay, polyurethane and compost volumetric removal capacities of, respectively, 24, 33, 38 and 24g alpha-pinenem−3 filter bedh−1 were attained and the gas pressure drops in the 60cm high filter beds measured at a superficial gas velocity of 35mh−1 were 70, 550, 180 and 250Pa. The results indicate that it is possible to develop biofilters based on the action of fungi with higher elimination capacities for alpha-pinene as reported in literature for bacterial biofilters. The use of polyurethane foam cubes is preferred because of the low gas pressure drop in combination with a high volumetric elimination capacity.  相似文献   

12.
13.
The in situ detection of mutagens by the TLC/Ames’ assay has been applied to aqueous discharges from a textile plant. The samples were fractionated in acid/neutral and basic fractions which subsequently were subject to the TLC/Ames’ test. The results demonstrate the presence of a number of both direct and indirect mutagens in the waste water. The chemical properties of these compounds are discussed in light of their chromatographic behaviour. The applicability of this method for characterizing mutagens in complex mixtures is demonstrated.  相似文献   

14.
C.M. Tu 《Chemosphere》1982,11(10):1027-1033
The relative toxicity of 23 pesticides, including 21 fungicides and two pyrethroid insecticides, on Rhizobiumjaponicum, four soybean pathogens, Fusariumoxysporum, Phytophthoramegasperma, Phytophthoraparasitica and Pythiumultimum, and germination of soybean seeds was compared with a highly toxic broad spectrum germicide, HgCl2 under laboratory conditions.  相似文献   

15.
P. Miramand  M. Unsal 《Chemosphere》1978,7(10):827-832
Acute toxicity of vanadium to some marine benthic and phytoplanktonic speciesThe acute toxicity of vanadium as sodium metavanadate to three benthic (Carcinusmaenas, Mytilusgalloprovincialis, and Nereisdiversicolor) and three phytoplankton species (Dunaliellamarina, Prorocentrummicans and Asterionellajaponica) were studied. In general the phytoplankton were found to be more sensitive than the benthic organisms used in our experiments. Considering the results from LC50 (9 days) experiments, the organisms, can be classified in the following decreasing order of sensitivity: D. marina (0.5 ppm), A. japonica (2 ppm), P. micans (3 ppm), N. diversicolor (10 ppm), C. maenas (35 ppm), M. galloprovincialis (65 ppm).  相似文献   

16.
The kinetics of oxidation of methylhydrazine (MMH) and 1,1-dimethylhydrazine (UDMH) by dissolved oxygen in water has been measured at various acidities as a function of catalyst (cupric ion) concentration. In dilute solutions the oxidation occurs through a cupric ion catalyzed process as well as by an uncatalyzed step. The extent of formation of nitrosodimethylamine (NDMA) depends upon the initial UDMH concentration. In dilute solutions NDMA is not formed, but in more concentrated solutions, NDMA formation increases with increasing UDMH content, reaches a maximum at 60–80% UDMH (by volume) and then decreases. The NDMA yield appears to approximately parallel the viscosity of the medium, and it is speculated that the factors which control viscosity may also be responsible for governing NDMA formation.  相似文献   

17.
C.M. Tu 《Chemosphere》1981,10(1):127-134
A study of the effect of 5 fungicide seed treatments on alfalfa (Medicagosativa L. var. Vernal) growth and nodulation by Rhizobiummeliloti 102F66 was conducted in a growth chamber. Captan, maneb and thiram exhibited greater toxicity to R. meliloti and alfalfa plants than that of benomyl and zineb. Recovery of the inhibitory effect was rapid.  相似文献   

18.
A new way of detecting trace elements in water is developed by using charged Particle Induced X-ray Emission (PIXE) analysis of cell walls of Chara corallina, a fresh water alga.  相似文献   

19.
The photolysis of methyl 2-benzimidazolecarbamate (Carbendazim, 1) in methanol and in the presence of singlet oxygen, was studied. Dimethyl oxalate 4, 2-aminobenzimidazole 7, benzimidazole 9, N,N′-dicarbomethoxyguanidine 13, monocarbomethoxyguanidine 14, monocarbomethoxyurea 15, and 2-guanidinobenzimidazole 17, were isolated and identified in this reaction.A mechanism that accounts for the formation of the photoreaction products, is presented.  相似文献   

20.
A single intraperitoneal administration of tin (II) tartrate to albino rats (2 mg Sn++100 g body wt) depressed the levels of hepatic glutathione reductase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, succinic dehydrogenase, reduced glutathione (GSH) and total sulfhydryl contents and led to an elevated level of tin. Serum aminotransferase levels were however, not affected but an increase in serum bilirubin and calcium levels was noticed.Invitro studies showed that tin tartrate upto a concentration of 2 uM did not affect the activity of liver enzymes tested, when the enzyme preparations were incubated with metallic salts during the time of assay. The critical concentration of tin for these parameters was at 5 uM.  相似文献   

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