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Mark Radosevich Samuel J. Traina Olli H. Tuovinen 《Journal of environmental science and health. Part. B》2013,48(4):457-494
Abstract An atrazine‐degrading bacterial isolate (M91–3) was able to utilize simazine and cyanazine as N sources for glucose‐dependent growth. The degradation of these three 5‐triazine herbicides was also investigated in binary and ternary mixtures. The organism used atrazine and simazine indiscriminately, whereas cyanazine degradation was slow and delayed until the depletion of the two other herbicides. There was no apparent effect of other commonly used herbicides on the rate of atrazine degradation by M91–3. 相似文献
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The purpose of the study was to evaluate the potential of phenanthrene and fluoranthene biodegradation in yardwaste compost materials. These polynuclear aromatic hydrocarbons were chosen for this work because they are relatively readily biodegradable and ubiquitous in the environment. Compost samples were incubated in biometers with 14C-labeled phenanthrene and the evolution of "4CO2 was assessed as a measure of mineralization. The '4CO2 evolution varied widely among replicate biometers, possibly as the result of (1) uneven and patchy colonization of phenanthrene-degrading microorganisms on compost particles, and (2) non-uniform dispersion of the labeled substrate spike into the yardwaste microenvironment. Mineralization of phenanthrene reached about 40%extent of 14CO2 evolution at best before leveling off, but the maximum varied from sample to sample and could be as low as 1%after three months. Active mineralization occurred at mesophilic and thermophilic temperatures. Methanol extraction was used to recover "4C from biometer samples that were spiked with "4C-labeled phenanthrene. Extraction for 24-48 h yielded 1-14% recovery of 14C, depending on the length of the preceding incubation. The low extraction yield and relatively low maximum mineralization(<40%) indicated that residual phenanthrene was sorbed and bound within the compost matrix in the biometer. Amendment ofbiometers with 0.05% Tween 80 or addition of water did not consistently enhance the mineralization. Variability in mineralization was greatly reduced in liquid samples taken from pre-enriched compost samples. Mineralization of 14C-labeled fluoranthene was negligible in biometers but could be stimulated by pre-enrichment with salicylate or naphthalene. Pre-enrichment also accelerated the mineralization of phenanthrene. 相似文献
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Erisman JW Vermeulen A Hensen A Flechard C Dämmgen U Fowler D Sutton M Grünhage L Tuovinen JP 《Environmental pollution (Barking, Essex : 1987)》2005,133(3):403-413
Monitoring and modelling of deposition of air pollutants is essential to develop and evaluate policies to abate the effects related to air pollution and to determine the losses of pollutants from the atmosphere. Techniques for monitoring wet deposition fluxes are widely applied. A recent intercomparison experiment, however, showed that the uncertainty in wet deposition is relatively high, up to 40%, apart from the fact that most samplers are biased because of a dry deposition contribution. Wet deposition amounts to about 80% of the total deposition in Europe with a range of 10-90% and uncertainty should therefore be decreased. During recent years the monitoring of dry deposition has become possible. Three sites have been operational for 5 years. The data are useful for model development, but also for model evaluation and monitoring of progress in policy. Data show a decline in SO(2) dry deposition, whereas nitrogen deposition remained constant. Furthermore, surface affinities for pollutants changed leading to changes in deposition. Deposition models have been further developed and tested with dry deposition measurements and total deposition measurements on forests as derived from throughfall data. The comparison is reasonable given the measurement uncertainties. Progress in ozone surface exchange modelling and monitoring shows that stomatal uptake can be quantified with reasonable accuracy, but external surface uptake yields highest uncertainty. 相似文献
5.
Modelling stomatal ozone flux across Europe 总被引:4,自引:0,他引:4
Emberson LD Ashmore MR Cambridge HM Simpson D Tuovinen JP 《Environmental pollution (Barking, Essex : 1987)》2000,109(3):403-413
A model has been developed to estimate stomatal ozone flux across Europe for a number of important species. An initial application of this model is illustrated for two species, wheat and beech. The model calculates ozone flux using European Monitoring and Evaluation Programme (EMEP) model ozone concentrations in combination with estimates of the atmospheric, boundary layer and stomatal resistances to ozone transfer. The model simulates the effect of phenology, irradiance, temperature, vapour pressure deficit and soil moisture deficit on stomatal conductance. These species-specific microclimatic parameters are derived from meteorological data provided by the Norwegian Meteorological Institute (DNMI), together with detailed land-use and soil type maps assembled at the Stockholm Environment Institute (SEI). Modelled fluxes are presented as mean monthly flux maps and compared with maps describing equivalent values of AOT40 (accumulated exposure over threshold of 40 ppb or nl l(-1)), highlighting the spatial differences between these two indices. In many cases high ozone fluxes were modelled in association with only moderate AOT40 values. The factors most important in limiting ozone uptake under the model assumptions were vapour pressure deficit (VPD), soil moisture deficit (for Mediterranean regions in particular) and phenology. The limiting effect of VPD on ozone uptake was especially apparent, since high VPDs resulting in stomatal closure tended to co-occur with high ozone concentrations. Although further work is needed to link the ozone uptake and deposition model components, and to validate the model with field measurements, the present results give a clear indication of the possible implications of adopting a flux-based approach for future policy evaluation. 相似文献
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A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study 总被引:1,自引:0,他引:1
Simpson D Ashmore MR Emberson L Tuovinen JP 《Environmental pollution (Barking, Essex : 1987)》2007,146(3):715-725
Two very different types of approaches are currently in use today for indicating risk of ozone damage to vegetation in Europe. One approach is the so-called AOTX (accumulated exposure over threshold of Xppb) index, which is based upon ozone concentrations only. The second type of approach entails an estimate of the amount of ozone entering via the stomates of vegetation, the AFstY approach (accumulated stomatal flux over threshold of Y nmol m(-2) s(-1)). The EMEP chemical transport model is used to map these different indicators of ozone damage across Europe, for two illustrative vegetation types, wheat and beech forests. The results show that exceedences of critical levels for either type of indicator are widespread, but that the indicators give very different spatial patterns across Europe. Model simulations for year 2020 scenarios suggest reductions in risks of vegetation damage whichever indicator is used, but suggest that AOT40 is much more sensitive to emission control than AFstY values. 相似文献
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The EMEP/MSC-W routine model for long-range atmospheric transport of sulphur and nitrogen includes a correction for the unresolved sub-grid-scale deposition in emission grid-squares. A constant fraction of the emissions is assumed to be directly deposited inside the first grid-square. Experiments have been performed to estimate the effects of using factors which vary with emission height and meteorological conditions. Results indicate that the constant local deposition factor used for sulphur dioxide in the routine model, is an overestimate, in particular for high-level emission sources. The change in annual deposition caused by the new local deposition factor for sulphur dioxide, is most clearly seen as a decreased deposition in the grid-squares with the largest emissions such as due for the former German Democratic Republic. The amount of this decrease strongly depends on the source height distribution. With the presently available emission data, a decrease of maximum 36% can be expected in individual grid squares. In grid-squares dominated by transboundary deposition, the increase is typically lower than 10%. 相似文献
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Tuovinen JP 《Environmental pollution (Barking, Essex : 1987)》2000,109(3):361-372
A discussion is presented on the application of micrometeorological deposition modelling principles to improve the characterisation of vegetation exposure to ozone and thus the use of critical levels as the basis of targeted emission control. The AOT40 (accumulated exposure over a threshold of 40 ppb or nl l(-1)) ozone exposure index is shown to impose a differential weighting that results in a high sensitivity, by a factor of two to 10 depending on the pollution climate, with respect to concentration. This makes it necessary to correct for systematic effects, such as the concentration profile below the measurement height, in order to justify a comparison with the biological data obtained from well-mixed exposure chambers. Available studies indicate a 50-70% lower AOT40 at the vegetation height. The resistance method for estimating the profile is extended to allow for stomatal effects that potentially bias the plant response predicted with an exposure index. This integrated profile-uptake correction refines the current approach and serves as a transitional step towards a real flux-based approach. For the latter, a new deposition parameterisation is tested against field observations. 相似文献
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Under certain conditions, sanitary sewer overflows (SSOs) containing raw wastewater may be discharged to public land and can contribute to environmental and public health issues. Although this problem has attracted the attention of local, state, and federal government and regulators, relatively little SSO abatement research has been published. This study used fixed-media bioreactors, a proven onsite technology in rural areas, to treat wet weather SSO wastewater and reduce its effects on the receiving water environment. The results of this 32-month laboratory study showed that fixed-media bioreactors, especially sand bioreactors, efficiently removed organic matter, solids, and nutrients during six-hour simulated SSO peak flows. Five-day biochemical oxygen demand (BODs) of the simulated SSO varied between 40 and 125 mg/L. The average effluent concentration of BOD5 was 13 mg/L in sand bioreactors at a hydraulic loading rate of 20.4 cm/h. In addition to having high hydraulic loadings, SSO events occur infrequently. This irregularity requires that treatment systems quickly start up and effectively treat wastewater after a period of no flow. This research found that an interval up to six months between two SSO peak flows did not affect the bioreactor performance. Based on this work, fixed-media bioreactors have the potential to reduce the effects of SSOs on the water environment by following proper design parameters and operation strategies. The pollution loading of approximately 18 g BODs/m2 x h is recommended for the efficient performance of sand bioreactors in the SSO treatment. 相似文献
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Tuovinen JP Simpson D Emberson L Ashmore M Gerosa G 《Environmental pollution (Barking, Essex : 1987)》2007,146(3):578-586
This study evaluates the robustness of the AOTX and AF(st)Y indices for assessing the ozone-induced risk to vegetation. These indices represent the accumulated concentration and stomatal flux, respectively, above a threshold value. The robustness is expressed as the sensitivity to changes in inputs and the uncertainty due to input errors. The input data are taken from a regional-scale chemical transport model. Both indices show increasing sensitivity with increasing threshold values. The sensitivity depends on the threshold and the characteristics of the frequency distribution for concentrations and stomatal fluxes. AF(st)Y appears less sensitive than AOTX for the thresholds adopted for critical levels. The couplings between concentration gradients and deposition algorithms complicate the assessment of the total uncertainty. For AF(st)Y, the uncertainty due to the modelled stomatal conductance may sometimes increase, but sometimes decrease, the overall uncertainty significantly. In particular, the maximum stomatal conductance plays an important role in determining the uncertainty. 相似文献