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1.
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   

2.
For the determination of the quantum yields of 1,2,3,4,7-pentachlorodibenzo-p-dioxin (1) and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (2), ten Pyrex glass photochemical cells were constructed and their correction factors determined. Quantum yields at 313 nm for 1 and 2 in aqueous acetonitrile (4:6 v/v) were (9.781 ± 2.376) 10?5 and (1.096 ± 0.020) × 10?4, respectively. These quantum yields and the measured absorption spectra were used to estimate the environmental phototransformation first-order rate constants and photochemical half-lives of 1 and 2 in water under conditions of variable sunlight intensity during various seasons from solar intensity data available in the literature. In summer, typical half-lives for the phototransformation of 1 and 2, respectively, near the surface of water bodies at 40° north latitude would be 364 ± 88 and 151 ± 3 h; whilst such values in winter would be 1257 ± 309 and 518 ± 10 h.  相似文献   

3.
Chen  Hui  Mao  Wei  Shen  Yiqiu  Feng  Weiwei  Mao  Guanghua  Zhao  Ting  Yang  Lanqin  Yang  Liuqing  Meng  Chunfeng  Li  Yong  Wu  Xiangyang 《Environmental science and pollution research international》2019,26(24):24609-24619

Phthalates (PAEs) in drinking water sources such as the Yangtze River in developing countries had aroused widespread concern. Here, the water, suspended particulate matter (SPM), and sediment samples were collected from 15 sites in wet and dry seasons in Zhenjiang, for the determination of six PAEs (DMP, DEP, DIBP, DBP, DEHP, and DOP) using the solid-phase extraction (SPE) or ultrasonic extraction coupled with gas chromatography-mass spectrometry (GC-MS). The total concentrations of six PAEs (Σ6PAEs) spanned a range of 2.65–39.31 μg L?1 in water, 1.97–34.10 μg g?1 in SPM, and 0.93–34.70 μg g?1 in sediment. The partition coefficients (Kd1) of PAEs in water and SPM phase ranged from 0.004 to 3.36 L g?1 in the wet season and from 0.12 to 2.84 L g?1 in the dry season. Kd2 of PAEs in water and sediment phase was 0.001–9.75 L g?1 in the wet season and 0.006–8.05 L g?1 in the dry season. The dominant PAEs were DIBP, DBP, and DEHP in water and SPM, DIBP, DEHP, and DOP in sediment. The concentration of DBP in water exceeded the China Surface Water Standard. The discharge of domestic sewage and industrial wastewater might be the main potential sources of PAEs. The risk quotient (RQ) method used for the risk assessment revealed that DBP (0.01 < RQ < 1) posed a medium risk, while DIBP and DEHP (RQ > 1) posed a high environmental risk in water, DIBP (RQ > 1) also showed a high risk in sediment.

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4.
The high density missile fuels RJ-5 and JP-9 resisted biodegradation when incubated with water/sediment suspensions collected from aquatic habitats. RJ-5 and JP-9 were not toxic to the microbial communities at concentrations of 400 mg per liter, but RJ-5 was toxic to Mysidopsis bahia in 96-hour acute tests (LC50 88 μg/l).  相似文献   

5.
Experiments were conducted to determine the factors responsible for the loss (adsorption, chemical hydrolysis, microbial degradation, etc.) of dichlorvos (2,2-dichlorovingl 0,0-dimethyl phosphate) in soil perfusion systems of Houston Black clay. The rate of disappearance from the perfusate (hence the rate of dichlorvos degradation in soil) was related directly to the presence of Bacilluscereus in the perfusion system, the pH of the system, and the extent of dichlorvos adsorption. Gas liquid chromatographic analyses of the perfusates showed that dichlorvos disappearance was rapid when B. cereus was added to a previously sterilized soil perfusion system (50% in 3.9 days). Under sterile conditions, 50% of the added dichlorvos was recovered after 10 days. When B. cereus was added to a mineral salts medium containing dichlorvos as sole ccrbon source, 49% of the initial dichlorvos concentration was degraded in 4 days. The organism was not capable of utilizing dichlorvos as a sole phosphorus source. Chemical hydrolysis of dichlorvos in aqueous, buffered, soil-free systems showed that hydrolysis did not occur in very acid systems (<pH 3.3), but increased with increasing pH values (26% in 4 days at pH 6.9), and was rapid at pH 9.3 (> 99% in 2 days). The extent of dichlorvos adsorption was determined by comparing the initial loss of dichlorvos in a sterile, soil-free extract solution with the initial loss in a sterile soil perfusion system. The rapid initial disappearance of dichlorvos in the presence of sterilized soil was attributed to soil adsorption of the pesticide. After 10 days both systems contained equal concentrations (50%) of dichlorvos. Non-biological mechanisms accounted for 70% of the total degradation of dichlorvos, while bacterial degradation accounted for 30% in the soil perfusion systems.  相似文献   

6.
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   

7.
Daniel Barug 《Chemosphere》1981,10(10):1145-1154
The degradation of the biocide bis (tributyltin) oxide by pur cultures of microorganisms has been studied. Attempts to isolate microorganisms able to utilize bis (tributyltin) oxide as sole carbon source, were unsuccessful. Of many bacterial species investigated Pseudomonas aeruginosa and Alcaligenes faecalis degraded sublethal amounts of bis (tributyltin) oxide during aerobic growth in the presence of suitable carbon sources. P. aeruginosa converted bis (tributyltin) oxide into monobutyltin and small amounts of dibutyltin derivatives. Similar results were obtained with growing mycelium of Coniophora puteana, Trametes versicolor and Chaetomium globosum. Microbial conversion of monobutyltin trichloride was not observed. Dibutyltin dichloride was converted into monobutyltin derivatives under certain sterile conditions.  相似文献   

8.
Yuan SY  Liu C  Liao CS  Chang BV 《Chemosphere》2002,49(10):1295-1299
Concentrations and microbial degradation rates were measured for eight phthalate esters (PAEs) found in 14 surface water and six sediment samples taken from rivers in Taiwan. The tested PAEs were diethyl phthalate (DEP), dipropyl phthalate (DPP), di-n-butyl phthalate (DBP), diphenyl phthalate (DPhP), benzylbutyl phthalate (BBP), dihexyl phthalate (DHP), dicyclohexyl phthalate (DCP), and di-(2-ethylhexyl) phthalate (DEHP). In all samples, concentrations of DEHP and DBP were found to be higher than the other six PAEs. DEHP concentrations in the water and sediment samples ranged from ND to 18.5 μg/l and 0.5 to 23.9 μg/g, respectively; for DBP the concentration ranges were 1.0–13.5 μg/l and 0.3–30.3 μg/g, respectively. Concentrations of DHP, BBP, DCP and DPhP were below detection limits. Under aerobic conditions, average degradation half-lives for DEP, DPP, DBP, DPhP, BBP, DHP, DCP and DEHP were measured as 2.5, 2.8, 2.9, 2.6, 3.1, 9.7, 11.1 and 14.8 days, respectively; under anaerobic conditions, respective average half-lives were measured as 33.6, 25.7, 14.4, 14.6, 19.3, 24.1, 26.4 and 34.7 days. In other words, under aerobic conditions we found that DEP, DPP, DBP, DPhP and BBP were easily degraded, but DEHP was difficult to degrade; under anaerobic conditions, DBP, DPhP and BBP were easily degraded, but DEP and DEHP were difficult to degrade. Aerobic degradation rates were up to 10 times faster than anaerobic degradation rates.  相似文献   

9.
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   

10.
Chlorination for drinking water forms various disinfection byproducts (DBPs) of trihalomethanes (THMs) and haloacetic acids (HAAs). Chlorination has been attributed to the destruction of activated aromatic sites of the natural organic matter (NOM) predominantly at electron rich sites. Experiments with Istanbul surface waters showed that the magnitude of the decrease in the ultraviolet (UV) absorbance at 272 nm (UV272) was an excellent indicator of destruction of these sites by chlorine. The main objective of the present study is to develop the differential UV272 absorbance (ΔUV272) related models for the prediction of the formation of THM, HAA, and their species in raw water samples from Terkos, Buyukcekmece, and Omerli lakes under different chlorination conditions. Significant factors affecting DBP formation in the raw waters were identified through numerical and graphical techniques. The R2 values of the models varied between 0.94 and 0.97, indicating excellent predictive ability for THM4 and HAA9 in the raw waters. The models were validated using additional data. The results of this study concluded that addition of ΔUV272 parameter into THM4 and HAA9 models make the prediction of these DBP compounds more precisely than those of DBP models developed in the past. A better understanding of these modeling systems will help the water treatment plant operators to minimize the DBP formation, providing a healthier and better drinking water quality as well as identifying strategies to improve water treatment and disinfection processes.  相似文献   

11.
We have studied the acute toxicity of fluoride ion to Gasterosteus aculeatus, Pimephales promelas, and juvenile Salmo gairdneri. LC50 values varied with species and (due to precipitation) initial water hardness. Exposure to elevated fluoride levels in water resulted in increased blood fluoride levels in Salmo gairdneri.  相似文献   

12.
Water hyacinth [Eichhorniacrassipes (Mart.) Solms] is an effective fertillizer, mulch, soil amendment and fodder for cattle and sheep. The consequences of the ability of the plant to accumulate heavy metals needs consideration. Small and large water hyacinth ecotypes collected from two “rural” rivers in Florida, the Peace and Withalachoochee respectively, were examined for an accumulation of cadmium from the natural environment. Less than trace amounts (below limits of detection, 2.5ppb) were present. Water hyacinths tested for cadmium accumulation under laboratory conditions exhibited a pronounced ability to absorb and accumulate the metal. The roots contained 0.982 mg of the 2.0 mg cadmium presented to the plant. The distribution of the metal within the plant was 76.7% in the roots, 22.4% in the stems with the remainder in the leaves. Of the total cadmium presented to the plant, 80.8 ± 3.0% was recovered by the plant after 7 days, the mean generation time of the plant. With increasing urbanization, accumulation of cadmium by water hyacinths exists. It is either an asset or a potential hazard and needs to be appreciated.  相似文献   

13.
Photolysis of the hydrophobic pollutant 1,1-bis(p-chlorophenyl)-2,2-dichloroethylene (DDE) was studied in aqueous suspensions of three well-characterized sediments. Results of the study can be described by equations that are based on a kinetic model that takes into account sorption kinetics. Analysis of the kinetic data using this model indicates that the sorbed DDE is, at equilibrium, about half in reactive sites and half in sites where the DDE is unreactive.  相似文献   

14.
A number of long term, low level petroleum hydrocarbon exposures were carried out from 1978 to 1981 in order to further evaluate use of the mixed function oxygenase (MFO) system in biological monitoring. The studies involved exposure, at ambient temperatures, of fish from three separate families including (a) spawning codfish (Gadus morhua), (b) post-spawned sculpins (Myoxocephalus octodecemspinosus), and (c) gonadally maturing flounder (Pseudopleuronectes americanus). MFO activity remained elevated approximately four-fold in the liver, and three-fold in the gills of codfish exposed for four months to water concentrations of 0.30–0.60 ppm petroleum, at ?1-1°C. Similarly, liver enzyme activity remained elevated approximately three-fold in sculpins exposed to very low levels (0.15–0.20 ppm) of petroleum for three months, at 4–12°C. Results indicate that several years may be required before hydrocarbon concentrations are reduced in petroleum contaminated sediments, such as those heavily impacted by oil spills, to non-inducing threshold levels. Oil contaminated sediment was, even after a year of weathering, quite effective in inducing a high level of MFO activity (seven-fold) in flounder, at 11-6°C. A number of factors that might detract from use of the mixed function oxygenase system in biological monitoring were not realized in these long term studies with petroleum hydrocarbons.  相似文献   

15.
The adsorption of the herbicide 14C-atrazine to the marine fungus Dendryphiellasalina was studied using sodium azide as an inhibitor of active uptake. Adsorption of atrazine (94 ppb) was found to reach equilibrium within six hours. Adsorption as a function of concentration (9.4 to 468 ppb) conformed to the empirically derived Freundlich equation giving a K value of 6.2. Atrazine on the fungal cell surface was easily desorbed by successive artificial seawater washes indicating a relatively loose binding. The ability of the marine fungus D.salina to remove 14C-atrazine from an artificial seawater medium suggests an environmental role in the transport and redistribution of atrazine in estuaries.  相似文献   

16.
A mixture of ten metals (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, Se and Zn) at the Great Lakes Water Quality Objective levels was found to reduce the primary productivity of four cultured freshwater algae (Scenedesmus, Chlorella, Anabaena and Navicula) as well as natural phytoplankton from Lake Ontario water. The metal mixture also caused a reduction in the reproduction and transport of an amino acid analogue (α-aminoisobutyric acid) by Ankistrodesmus. The depuration and exchange of the amino acid analogue were not affected by the metal mixture. The nitrogenase activity of Anabaena was, however, reduced in the presence of the metal mixture.  相似文献   

17.
Aliphatic hydrocarbons and non-polar aromatic compounds have been analyzed after a spill of grude oil at Baltic Sea 1979 from drifting weathered oil glumps, sediment and sediment trap samples and bivalves at five areas of the Finnish Archipelago Sea. Mytilus and flounder muscles and flounder livers were analyzed 1980 and 1981 from three of the previous five areas. The glumps were shown to be weathered grude oil. Sediment trap samples on the visibly contaminated area contained higher amounts of oil residues and in different ratios than the bottom sediments at the same areas. Extra local aliphatic hydrocarbon pollution was detected from the sediment traps at the reference area. Bivalves contained high amount of oil residues at visibly polluted but in some visibly non-polluted areas also 1979. Any significant decontamination was not detected at summer 1979 but next year the Mytilus samples contained only traces if any and 1981 no detectable levels of aromatic oil residues. Aliphatic hydrocarbon residues in flounders showed no regional differences and no significant change of levels between 1980 and 1981. In contrary, the aromatic oil residues decreased to the non-detectable level in flounder muscles and to a significantly lower level in flouder livers 1981 related to 1980. Linear correlations of the analysis results are discussed.  相似文献   

18.
The effect of cadmium and of zinc on the rate of uptake of a pentose sugar xylose and an aminoacid tryptophan by the intestine of a teleost fish, Heteropneustesfossilis was studied under two experimental conditions. In the first, four concentrations of cadmium or zinc (1.0 mM, 0.1 mM, 0.01 mM and 0.001 mM) mixed with the nutrient solution were filled in the intestinal sacs, and the rate of absorption was recorded after 1 h at 23°C. In the second experiment fish were exposed by bath to a sublethal concentration of cadmium (0.26 mg/1) or zinc (4 mg/1) for 15 and 30 days and the rate of absorption of the two nutrients was measured. The activity of intestinal Na+, K+ activated adenosine triphosphatase was also assayed. The two heavy metals at all the four concentrations decreased the rate of intestinal transport of nutrients. Increase in the concentration of each of the heavy metals decreased the uptake of nutrients, but the decreases were not linear. The rate of intestinal absorption of the two nutrients was also reduced by exposure of fish to the heavy metals invivo. The activity of Na+, K+ ATPase decreased invitro with all four concentrations of cadmium and zinc and was diminished in fish exposed for 15 and 30 days. Of the two heavy metals, cadmium was more effective in reducing the rate of transport of xylose and tryptophan.  相似文献   

19.
Accumulation of 14C labelled bis(tributyltin) oxide (TBTO) by the mud crab, Rhithropanopeusharrisii, was determined through short-term exposure to labelled water and food. The potential for trophic accumulation during chronic low level exposure is emphasized.  相似文献   

20.
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   

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