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331.
Whole effluent toxicity was assessed for the fish Oryzias latipes and the prawn Macrobrachium nipponense for 18 h in a dilution series (0-66%) of the inflow and effluent of a municipal waste water treatment plant as well as waste water from a teramycin producing pharmaceutical industry, before, during and after a pilot laboratory purification process. The waste waters caused acute toxicity as measured by inhibition of light emission in the luminiscent bacterium Vibrio qingaiensis sp. nov. (Q67). EROD and aryl hydrocarbon hydroxylase activity in in vitro carp liver-cells showed a dose-dependent toxic response to the municipal waste water. Behavioural responses and time-to-death of fish and prawn, recorded online with the "Multispecies Freshwater Biomonitor" proved to be concentration- and time-dependent sensitive toxicity indicators in both types of waste water. Behaviour changed stepwise from normal activity to (increased or decreased) activity to more time spent on ventilation and finally to increased morbidity at higher concentration and time of exposure. The municipal waste water treatment plant managed to reduce toxicity to bacteria (Q67), prawn and fish. The pharmaceutical waste water treatment process still has to be improved, in order to reduce toxicity for fish and prawn.  相似文献   
332.
Zheng MH  Bao ZC  Zhang B  Xu XB 《Chemosphere》2001,44(6):1335-1337
An extensive investigation on the input, formation and fate of PCDD/Fs in a pulp mill using reeds as raw materials in China was carried out. The main PCDD/Fs input in the production process came from reeds, which may be contaminated by PCDD/Fs from sodium pentachlorophenate to control snailborne schistosomiasis. High levels of I-TEQ in the products were observed.  相似文献   
333.
Sorption capability of bedrock components from a fractured chalk province was evaluated using ametryn, phenanthrene, m-xylene, 2,4,6-tribromophenol, and 1,2-dichloroethane. Sorption isotherms for the four aromatic compounds were nonlinear on gray (unoxidized) chalk. Over the studied solution ranges, the distribution coefficient decreased by factor of 3 for phenanthrene and m-xylene, a factor 4 for ametryn, and by an order of magnitude for 2,4,6-tribromophenol. In contrast, 1,2-dichloroethane displayed a linear isotherm. The importance of polar interactions for ametryn sorption was evaluated by normalizing sorption to an "inert" solvent, n-hexane. n-Hexane-normalized sorption of ametryn was much greater than that of phenanthrene, presumably due to ametryn participation in hydrogen bonding interactions. In sharp contrast to sorption to gray chalk, sorption to white (oxidized) chalk is 100- to 1000-fold lower at any given solution concentration. The much greater sorption on gray chalk cannot be explained by specific surface area, clay content, or organic matter content; thus, the nature of the organic matter is considered to control sorption in the chalk samples. Gray chalk sorption capacity estimates for ametryn and 2,4,6-tribromophenol are similar, which, together with evidence of competition for sorption sites, suggests that the limited capacity sorption domain for both compounds is similar.  相似文献   
334.
A study was conducted from summer 1995 to summer 1997 to assess the seasonal occurrence of pesticide residues and other organic contaminants, polychlorinated biphenyls (PCBs), in water at the estuaries of Rosetta and Damiatta branches of the Nile river. The results indicated that organochlorine compounds (OCs) including HCB, lindane, p,p'-DDE, p,p'DDD, p,p'-DDT, aroclor 1254 and aroclor 1260 were present in all the water samples at concentration levels ranging between 0.195-0.240, 0.286-0.352, 0.035-0.067, 0.019-0.033, 0.024-0.031, 0.390-0.70 and 0.166-0.330 microgram/l, respectively. The levels of these compounds were higher in water of Damiatta branch than those found in water of Rosetta branch. Aldrin, dieldrin and endrin were not detected in all water samples. Only 4 compounds from 36 organophosphorus insecticides, fungicides and s-triazine herbicides tested were detected in water samples collected during summer and autumn seasons from Rosetta branch. The concentration levels of these detected compounds, dimethoate, malathion, captan, and ametryne, ranged from 0.011 to 0.340 microgram/l, respectively. Similar compounds during the same seasons as found in water of Rosetta branch were also detected in water of Damiatta branch except ametryne. The levels of the detected compounds (dimethoate, malathion and captan) ranged between 0.030 and 0.330 microgram/l. The levels of detected organophosphorus insecticides, fungicides and s-triazine herbicides were in the order: dimethoate > malathion > captan > ametryne.  相似文献   
335.
A multi-step mass transfer-biodegradation model is developed to describe the bioactive adsorber dynamics for the biotreatment of livestock generated odor causing VOCs (VOC-odor) based on a biologically active dust particle (BADP) process. The BADP process employs dust particles with adsorbat-acclimated microbial culture to form the bioactivated dust particles (BDP) for the simultaneously adsorption, mass transfer, and biodegradation of VOC-odor. The model incorporating age and size distributions of BDP considers the equilibrium partitioning of VOC-odor at BDP and bulk gas interface that followed by two kinetic processes occurring in the bulk and solid phases: bulk gas mass transfer-biodegradation and BDP biofilm diffusion-biodegradation. Analytical equations indicate that the overall biotransformation rate of VOC-odor in a BADP process is controlled by BDP-bulk gas equilibrium processes represented by the slowest of two kinetic processes determined by a dimensionless group: the Thiele modulus (phi 2), the Damkohler number (Da) and the Biot number (Bi). Computer simulations demonstrate that the most favorable performance of a BADP system in reducing VOC-odor concentrations is operated under Bi < 1, Da < 1, or Bi > 1 phi 2 < 1; indicating diffusion-biodegradation controlled. The dimensionless group can be used to identify the dominant rate-limiting processes and to evaluate the overall biomineralization rate in a BADP process. Simulation results allow the determination of preliminary design for prototype development.  相似文献   
336.
The aim of this paper was to investigate the capacity of a small water fern, Azolla caroliniana Willd. (Azollaceae), to purify waters polluted by Hg and Cr. Many plants are capable of accumulating heavy metals (called hyperaccumulators) and one of them is the water fern A. caroliniana. During 12 days of the experiment the fern was grown on the nutrient solution containing Hg2+, Cr3+ and CrO4(2-) ions, each in a concentration 0.1, 0.5 and 1.0 mg dm(-3). The presence of these ions caused a 20-31% inhibition of A. caroliniana growth, the highest in the presence of Hg(II) ions, in comparison to the control. After day 12 of the experiment, metal contents the solution decreased to 0-0.25 mg dm(-3), and this decrease comprised between 74 (Cr3+ 1.0 mg dm(-3) treatment) and 100% (CrO4(2-) 0.1 mg dm(-3) treatment). The fern took a lesser quantity of the metals from 0.1 mg dm(-3) treatments compared to 0.5 and 1.0 mg dm(-3) treatments. In the A. caroliniana tissues the concentration of heavy metals under investigation ranged from 71 to 964 mg kg(-1) dm; the highest level being found for Cr(III) containing nutrient solution.  相似文献   
337.
Copper tolerance,uptake and accumulation by Phragmites australis   总被引:1,自引:0,他引:1  
Ye ZH  Baker AJ  Wong MH  Willis AJ 《Chemosphere》2003,50(6):795-800
Copper (Cu) uptake and accumulation of five populations of Phragmites australis growing in two mine sites (Parys Mountain, Wales, UK and Plombières, Belgium) contaminated with Cu and three 'clean' sites (Felixstowe, UK; Wisbech, UK and Mai Po, Hong Kong) were studied under field and glasshouse conditions. Cu tolerances in these populations of seedlings raised from seeds collected from the above five sites were also studied under glasshouse conditions. Although concentrations of Cu in the plant tissues (leaves, stems, rhizomes and roots) of P. australis and the associated soils from the Cu-contaminated sites were significantly higher than those of the plant tissues and the soils collected in the clean sites, small differences were found between the two Cu-contaminated populations and the three clean populations when seedlings were grown in 0.1 and 0.5 microg ml(-1) Cu treatment solutions. In general, different populations of seedlings showed similar growth responses, metal uptake and indices of Cu tolerance when cultured in the same Cu treatment solution for 3 weeks. There was insufficient evidence to support the hypothesis that the Cu-contaminated populations have evolved to Cu-tolerant ecotypes.  相似文献   
338.
339.
Bioconcentration and biokinetics of heavy metals in the earthworm   总被引:3,自引:0,他引:3  
This study examines the steady state and non-steady state kinetics of five metals, cadmium, copper, lead, nickel, and zinc in earthworms. The steady state kinetics are based on field studies in which worms from contaminated and uncontaminated sites were collected and measurements were made of concentrations in the earthworms and soils. For each of the metals, evidence suggests that bioconcentration depends on the metal concentrations in the soil; bioconcentration is greater at lower soil concentrations. The studies of non-steady state kinetics involve uptake and elimination experiments in which worms are transferred from an uncontaminated soil to a contaminated soil (uptake studies) or from a contaminated soil to an uncontaminated soil (elimination studies). The voiding time is shown to be an important experimental variable in determining the measured levels of metal in earthworms because experimental measurements are usually made on a worm-soil complex (i.e. the soft tissue of the worm and the soil in the gut of the worm). Thus, for metals that are bioconcentrated in worm tissue, increasing the voiding period increases the concentration of the metal in the worm-soil complex. Conversely, for metals that are not bioconcentrated, increasing the voiding time leads to a decrease in concentrations in the worm-soil complex.  相似文献   
340.
Chiu KK  Ye ZH  Wong MH 《Chemosphere》2005,60(10):1365-1375
Vetiveria zizaniodes (vetiver) is commonly known for its effectiveness in soil and sediment erosion control. It can tolerate to extreme soil conditions and produce a high biomass even growing in contaminated areas. Zea mays (maize) can also produce a very high biomass with a fast growth rate and possesses some degree of metal tolerance. A greenhouse study was conducted to investigate the feasibility of using vetiver and maize for remediation of arsenic (As)-, zinc (Zn-), and copper (Cu)-amended soils and evaluate the effects of chelating agents on metal uptake by these plants. Vetiver had a better growth (dry weight yield of root and shoot) than maize under different treatment conditions. The effects of different chelating agents on As, Zn, and Cu extraction from soil to soil solution were studied. Among the nine chelating agents used, it was noted that 20 mmol NTA could maximize As and Zn bioavailability, while 20 mmol HEIDA could maximize Cu bioavailability in the soil solution. The surge time in maximizing metal uptake ranged from 16 to 20 days which indicated that timing on plant harvest was an important factor in enhanced metal accumulation. In general, vetiver was a more suitable plant species than maize in terms of phytoextraction of metals from metal-contaminated soil. Application of NTA in As-amended soil and HEIDA in Cu-amended soil at the rate of 20 mmol kg(-1) increased 3-4-fold of As and Cu in shoot of both plants, whereas application of NTA (20 mmol kg(-1)) increased 37- and 1.5-fold of Zn accumulation in shoot of vetiver and maize, respectively. The potential environmental risk of metal mobility caused by chelating agents used for phytoextraction should not be overlooked.  相似文献   
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