土壤中苯并[a]芘对白符跳(Folsomia candida)的生态毒性研究

苯并(a)芘（B[a]P）是一种典型的多环芳烃（PAHs）,在油田周边和污灌区土壤中有较高的检出率。在污染土壤生态风险评估和制定土壤生态基准时,常用土壤跳虫作为敏感生态受体,但已有研究表明,目前常用的成虫生长率、死亡率和繁殖率等指标特征往往仅对土壤中高剂量B[a]P产生毒性响应。采用白符跳（Folsomia candida）的生态毒理试验筛选可用于较低剂量B[a]P下新的敏感指标特征,并比较其在两种典型地带性土壤天津潮土和鹰潭红壤之间的敏感性差异。结果表明,幼虫的生长指标最敏感,能对土壤较低浓度B[a]P产生毒性响应,可作为指示土壤B[a]P毒性的指标。四个指标的敏感度依次为：幼虫体长>成虫体长>繁殖数>存活数。B[a]P对白符跳的毒性效应在两种土壤类型间存在显著差异（红壤和潮土中幼虫体长的最低效应浓度（LOEC）值分别为1和500 mg kg^-1）,可能受土壤理化性质,特别是有机质含量和pH的影响,在制定土壤生态基准时需对不同土壤的毒性数据进行归一化校正。     

Flux of Benzo(a)pyrene to the Ground Surface and its Distribution in the Ecosystem

Benzo(a)pyrene (BP) has been investigated in bulk atmospheric deposition, moss, needles of pine and some species of vascular plants. At two remote Lithuanian sites, for 1990-1995 the flux of benzo(a)pyrene from the atmosphere to the ground surface varied between 0.3 to 4.8 μg-2 mo-1. Consequently the territory of Lithuania (65,000 km2) yearly was exposed to 624-2574 kg of carcinogen. The distribution of BP in soil and various vascular plant tissues (Trifolium tepens, Elitrygea repens, Thymus serpyllum) indicates that benzo(a)pyrene is assimilated by flora. The concentration of BP is different in various organs of vascular plants and mostly depends on the degree of soil pollution. More than 300 samples of moss, mostly Hylocomium splendens and Pleurozium schreberi were analyzed for BP. From 3.1 to 896.0 μg kg-1 of BP were measured in the moss samples. The flux of BP to the ground surface correlates well with its concentration in moss. A map of BP flux across Lithuania was created.     

Biological Parameters Towards Polycyclic Aromatic Hydrocarbons Pollution: A Study with Dicentrarchus labrax L. Exposed to the Model Compound Benzo(a)pyrene

The objective of the present study was to investigate the short-term effects of benzo(a)pyrene (BaP) on juvenile sea bass (Dicentrarchus labrax L.) using a multiparameter approach. At the end of the 96?h of exposure to a range of BaP concentrations (2?C256???g?l^?1) in laboratorial conditions, a suite of biomarkers involved in biotransformation pathways, oxidative stress and damage, neurotransmission and energetic metabolism were analysed. Levels of BaP metabolites in bile and BaP-type compounds in tissues were also included as biomarkers of exposure, and the post-exposure swimming velocity was used as a toxicity endpoint at a higher level of biological organisation. In addition, a time-series experiment on the levels of bile BaP metabolites was also performed. Increased levels of BaP metabolites in bile and BaP-type compounds in liver and brain of exposed fish were found, indicating BaP uptake, metabolisation and distribution by different tissues. BaP induced oxidative stress and damage, but no significant effects on the post-exposure swimming velocity, neurotransmission and energetic pathways were found. An increase in the levels of BaP metabolites in bile over time was also observed, reaching a threshold similar at all the concentrations tested. Overall, this integrative multiparameter study reflecting different biological responses of D. labrax was suitable to assess the effects caused by the short-term exposure to BaP and may be useful in the marine environmental risk assessment of polycyclic aromatic hydrocarbons pollution. The observed toxic effects also highlight the relevance of short-term exposure to relatively high concentrations of chemicals, as can occur in the case of punctual heavy chemical releases, such as oil spills in the marine environment.     

土壤pH、水分及温度对长期污染土壤中苯并[a]芘动态变化的影响初探

以受多环芳烃长期污染农田土壤中苯并[a]芘(B[a]P)为研究对象,采用室内模拟试验研究了pH、水分和温度对土壤中B[a]P的动态变化的影响。结果表明,供试污染土壤中B[a]P能被土著微生物快速去除,其消减过程受到pH、水分和温度的影响。初始pH为4.6、5.9和7.3的泥浆中B[a]P在7天内的去除率分别为43.8%、37.8%和14.0%。在土壤水分为22%、43%、65%和87%田间持水量,温度为28℃条件下培养80天后土壤中B[a]P的去除率分别为42.5%、96.6%、96.3%和34.3%。在土壤pH为4.5,土壤水分为60%±5%田间持水量,温度为25℃和40℃条件下土壤中B[a]P的半衰期分别为33天和16天。可见,pH、水分和温度等环境条件对土壤中B[a]P的消减过程具有明显的影响,可通过人为调控强化B[a]P污染土壤的生物修复。     

Investigating the Uncertainty in Predicting Responses to Atmospheric Deposition using the Model of Acidification of Groundwater in Catchments (MAGIC) within a Generalised Likelihood Uncertainty Estimation (GLUE) Framework

This study investigates the uncertainty associated with the modelled response of a catchment to historic and predicted future acidic deposition for the period 1851–2041. The MAGICmodel is applied within a GLUE framework to the 3.88 km² Afon Gwy catchment at Plynlimon, Wales. Nine million Monte Carlo simulations resulted in 5700 being accepted as behaviouralas defined by a fuzzy measure comparing observed to simulated variables. Model output and parameter sensitivity analysis indicate that, for this example where weathering rates are low,model dynamics are limited compared to control exerted by modelinitial conditions and by the specified acidic deposition boundary conditions. The results show that despite the small number of behavioural simulations, they are widely spread acrossthe ranges for most of the parameters varied. The GLUE methodology allows simulated prediction ranges for important variables to be presented as quantitative likelihood weighteduncertainty estimates rather than a single prediction for eachvariable over time.     

Addition of porphyrins to cigarette filters to reduce the levels of benzo[a]pyrene (B[a]P) and tobacco-specific N-nitrosamines (TSNAs) in mainstream cigarette smoke

Tobacco-specific N-nitrosamines (TSNAs) and benzo[a]pyrene (B[a]P) in mainstream cigarette smoke (MSS) cause smoking-related diseases and environmental pollution. Porphyrins were added to cigarette filters to reduce B[a]P (porphyrins A-E) and TSNAs (porphyrin F) in MSS. The porphyrin-B[a]P and porphyrin F-TSNAs (N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and N-nitrosonornicotine (NNN)) interactions were investigated by fluorescence quenching and UV-visible spectroscopy. The correlation coefficients were 0.987-0.997 (B[a]P) and 0.994-0.999 (TSNAs), and the binding constants were (1.67-5.02) × 10(5) (B[a]P) and 3.42 × 10(3)-1.40 × 10(4) (TSNAs). Up to 36.72% of B[a]P and 46.67% of the TSNAs were eliminated from MSS, with greater reductions when more porphyrin was included in the filter. With the same mass of porphyrin in the filter, the reduction trend for B[a]P by porphyrins A-E was A > B > C > D > E. The reduction trend for TSNAs by porphyrin F was NNN > NAB > NNK > NAT. The porphyrin mode of action is possibly through strong π-π interactions.     

Long-Term Soil Acidification Model (LTSAM) Development and Application for Analyzing Soil Responses to Acidic Deposition

A long-term soil acidification model (LTSAM) which can describe calcareous and non-calcareous soil responses to acidic deposition is developed based on the conservation of alkalinity and Ulrich buffer ranges. The model which considers nine major ions of armospheric deposition, has focused on certain soil processes (weathering of carbonates, silicates, and aluminum (Al) oxides or hydroxides, cation exchange, anion retention, and CO2 solubility). After comparing the model design and simulation results with the SMART, the paper describes several numerical experiments on the sensitivity of calcareous drab soil in Beijing and red earth (nearly dystric cambisol) in Wenzhou of Zhejiang Province in Southern China to acidic deposition scenarios. The modelling results indicate that increase or decrease in atmospheric deposition of base cations and not only changes in deposition of sulfate (S) and H+ must be considered in assessment of critical loads both for red earth and calcareous drab soil.     

An Application of Geographic Information System (GIS) to a Fictitous Thermal Power Plant in Mersin,Türkiye: An Application of Dispersion Modelling Coupled with GIS

In this study, local air quality impacts of a proposed conventionalcoal-fired power plant in the ?çel region has been investigated using numerical dispersion modeling studies coupled with a GIS application. Within the impact area of the facility, Industrial Source Complex Short Term (ISCST2) dispersion model has been used to estimate ground-level concentrations of air pollutants originating from the power plant. For the same impact area, GIS applications have been utilised to determine the agricultural yield distribution. For this purpose, relevant satellite images were digitised, classified and statistically analyzed. Based on the predicted ground-level pollutant concentrations and sensitivity of the agricultural crops to the pollutants, agricultural yield loss was estimated for the impact area.The results have been quantified and valuated in monetary terms for the purpose of performing an environmental cost benefit analysis. Comparison of the conventional cost benefit analysis with the environmental cost benefit analysis showed the significance of the external cost of the proposed facility, resulting from the environmental damages.

     

Atmospheric Deposition of Nitrogen to a Caribbean Coastal Zone (Cayo Coco,Cuba): Temporal Trends and Relative Importance as a Nitrogen Source

Nitrogen (N) deposition to the ocean is thought to be increasing worldwide, but the amount of coastal and open ocean measurements is very limited. In this paper, we assess N deposition in the coastal zone of Cayo Coco, in central Cuba, during a multi-annual period (2005–2007). Wet and dry N depositions were estimated based on the NH₄⁺ and NO_x^– concentrations in the rain. Cold fronts and troughs, coming from the west, contributed most to rain (41%) and to N deposition, followed by tropical waves and storms coming from the east, which caused 31% of the rain. Average concentrations of NH₄⁺ and NO_x^– in the rain were 8.8 and 8.3 μM. NO_x^– presented a clearly decreasing trend (0.26 μM per month), decreasing by half during 2005–2007. Total N deposition averaged 3.23 kg N ha⁻¹ year⁻¹, similar to that found in Virgin Islands and Puerto Rico, but lower than previously measured in Cuba and in nearby areas of the USA and than model predictions for the oceanic region around Cuba. These low values and the decreasing trend found are attributed to drastic reduction of fossil fuel and fertilizer use in Cuba since 1990. Because land input has decreased even more drastically, deposition seems to be nowadays the most important N source to the coastal zone of Cayo Coco. The δ¹⁵N range of seagrass (Thalassia testudinum) and macroalgae (Penicillus dumetosus) in the area (−1.83‰ to 3.02‰ and +1.02‰ to +4.17‰, respectively) sustain that atmospheric sources (deposition and N₂ fixation) comprise 70–90% of the N budget.     

Predicting Recovery from Acidic Deposition: Applying a Modified TAF (Tracking and Analysis Framework) Model to Maine (USA) High Elevation Lakes

We adapted a reduced-form model, built to predict the aquatic effects of alternative nitrogen and sulfur emissions scenarios on Adirondack lakes, New York, for use on high elevation lakes of Maine (HELM), USA. The Tracking and Analysis Framework (TAF) model was originally designed to evaluate the biotic, economic, and health effects of acid deposition. The TAF model developed in our study was used to assess the biotic effects of different levels of sulfate deposition resulting from alternative emissions scenarios. The aquatic portion of the model is based on a lumped-parameter watershed chemistry model, MAGIC (Model of Acidification of Groundwater in Catchments). The original TAF model was built by calibrating MAGIC to 33 lakes in the Adirondack Mountains. We calibrated MAGIC to 78 HELM lakes, and built reduced-form models from these MAGIC predictions. We evaluated TAF predictions of acid neutralizing capacity (ANC), a fish acid stress index (ASI), and the probability of fish presence in 2030 for four different SO₂ emissions-reduction scenarios. The most dramatic emissions reduction scenario produced only modest increases in mean ANC (16.8 μeq/L ± 7.9 μeq/L) and slight increases in mean predicted probability of presence of acid-sensitive fish (0.07± 0.09) across all lakes. However, a small number of lakes were predicted to have more substantial increases in ANC and improvements in other conditions for acid-sensitive fish. Our results reflect the reality that many of the high elevation lakes of Maine historically had low ANC and that some were even acidic in pre-industrial times. Thus, ’recovery’ for most of the high elevation lakes of Maine will be modest under any scenario of reduced acidic deposition.     

Application of a molecular sensory science approach to alkalized cocoa (Theobroma cacao): structure determination and sensory activity of nonenzymatically C-glycosylated flavan-3-ols

Application of comparative taste dilution analyses on nonalkalized and alkalized cocoa powder revealed the detection of a velvety, smoothly astringent tasting fraction, which was predominantly present in the alkalized sample. LC-MS/MS analysis, 1D- and 2D-NMR, and CD spectroscopy as well as model alkalization reactions led to the unequivocal identification of the velvety, smoothly astringent molecules as a series of catechin- and epicatechin-C-glycopyranosides. Besides the previously reported (-)-epicatechin-8-C-beta-D-galactopyranoside, additional flavan-3-ol-C-glycosides, namely, (-)-epicatechin-8-C-beta-D-glucopyranoside, (-)-catechin-8-C-beta-D-glucopyranoside, (-)-catechin-6-C-beta-D-glucopyranoside, (-)-epicatechin-6-C-beta-D-glucopyranoside, (-)-catechin-8-C-beta-D-galactopyranoside, (-)-catechin-6-C-beta-D-galactopyranoside, (-)-catechin-6-C,8-C-beta-D-diglucopyranoside, (-)-epicatechin-6-C,8-C-beta-D-digalactopyranoside, (-)-catechin-6-C,8-C-beta-D-digalactopyranoside, and epicatechin-6-C,8-C-beta-D-diglucopyranoside, were identified for the first time in cocoa. Most surprisingly, these phenol glycoconjugates were demonstrated by model experiments to be formed via a novel nonenzymatic C-glycosylation of flavan-3-ols. Using the recently developed half-tongue test, human recognition thresholds for the astringent and mouth-drying oral sensation were determined to be between 1.1 and 99.5 micro mol/L (water) depending on the sugar and the intramolecular binding position as well as the aglycone.     

Application of the Regional Mercury Cycling Model (RMCM) to Predict the Fate and Remediation of Mercury in Onondaga Lake,New York

Onondaga Lake exhibits elevated concentrations of total mercury (HgT) and methyl-mercury (MeHg) in the water column, sediments and fish tissue due to industrial inputs, wastewater discharge and urban runoff. The steady-state Regional Mercury Cycling Model (RMCM) was calibrated to Onondaga Lake and applied to evaluate various remediation scenarios. Because of detailed data available for Onondaga Lake, the RMCM was effectively calibrated. Model predictions of water column and fish concentrations of Hg generally agreed with measured values. The model underestimated concentrations of Hg in sediments. Mass balance calculations show that inputs of HgT largely originate from tributary and wastewater inflows to the lake. In contrast, MeHg is largely derived from internal production. Model calculations suggest that elimination of Hg inputs from wastewater effluent and of drainage from a former chlor-alkali facility could greatly decrease Hg concentrations in fish tissue.     

Electrochemical Production of Ferrate (Iron VI): Application to the Wastewater Treatment on a Laboratory Scale and Comparison with Iron (III) Coagulant

This paper presents a comparative study of the performance of ferrate(VI), FeO ₄ ^2? , and ferric, Fe(III), towards wastewater treatment. The ferrate(VI) was produced by electrochemical synthesis, using steel electrodes in a 16 M NaOH solution. Domestic wastewater collected from Hailsham North Wastewater Treatment Works was treated with ferrate(VI) and ferric sulphate (Fe(III)). Samples were analysed for suspended solids, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and P removal. Results for low doses of Fe(VI) were validated via a reproducibility study. Removal of phosphorous reached 40% with a Fe(VI) dose as low as 0.01 mg/L compared to 25% removal with 10 mg/L of Fe(III). For lower doses (<1 mg/L as Fe), Fe(VI) can achieve between 60% and 80% removals of SS and COD, but Fe(III) performed even not as well as the control sample where no iron chemical was dosed. The ferrate solution was found to be stable for a maximum of 50 min, beyond which Fe(VI) is reduced to less oxidant species. This provided the maximum allowed storage time of the electrochemically produced ferrate(VI) solution. Results demonstrated that low addition of ferrate(VI) leads to good removal of P, BOD, COD and suspended solids from wastewater compared to ferric addition and further studies could bring an optimisation of the dosage and treatment.     

湿软土壤剪切应力—剪切速度—时间关系及其应用(第3报)——湿软土壤上履带板的推力计算

为了合理地预测湿软地上履带行走装置的推进力,对履带板的推力计算模型进行了修正。修正后的计算模型考虑了土壤受剪速度对其剪切应力的影响。实验结果表明履带板的推力介于考虑和不考虑履剌效应的两个理论值之间。     

Determination and Evaluation of Sampling Velocity in a Simple Passive Sampling Method to Monitor HNO3(g) in Ambient Air

We evaluated the applicability of a simple passive sampling method to quantify HNO₃(g) in ambient air. The method has the advantages of not only ease of operation but also low cost. A sampling velocity of 214 m day^?1 was determined based on the concentration of HNO₃(g) measured by the four-stage filter-pack method at nine sites located within a 250?×?250-km area in Japan. This sampling velocity was applied at sites located outside of area to verify the applicability and accuracy of the simple passive sampling method. The variation in the results for the application of the sampling velocity ranged from 0.39 to 0.95. The simple passive sampling method should be applied to sites with different meteorological conditions, and the obtained data should be used to obtain more significant information and/or to indicate the need for further developments in the methodology.     

Application of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay to a flow injection system for the evaluation of antioxidant activity of some pure compounds and beverages

The 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*)(+)) assay was adapted to a flow injection (FI) system to obtain a sensitive and rapid technique for the monitoring of antioxidant activity of pure compounds and complex matrixes, such as beverages and food extracts. The FI system includes a HPLC pump that flows the mobile phase (a solution of ABTS(*)(+) in ethanol) through a 20 microL loop injector, a single bead string reactor filled with acid-washed silanized beads, a delay coil and a photodiode array UV-visible detector. The technique was very sensitive, with limits of detection and of quantification of 4.14 and 9.29 micromol of Trolox/L, respectively, and demonstrated high repeatability and reproducibility. The proposed technique was then applied to the evaluation of the antioxidant activity of some pure compounds, demonstrating good agreement with published data obtained by the original spectrophotometric ABTS(*)(+) assay. Finally, the total antioxidant activity of 10 beverages was determined by both the proposed and the original method. The values ranged from 0.09 mmol L(-)(1) for cola to 49.24 mmol L(-)(1) for espresso coffee and did not result significantly different from those obtained by the original spectrophotometric ABTS(*)(+) assay (Student's paired t-test: t = 1.4074, p = 0.1929). In conclusion, the proposed FI technique seems suitable for the direct, rapid and reliable monitoring of total antioxidant activity of pure compounds and beverages and, due to the ability to operate in continuous, it allows the analysis of about 30 samples h(-)(1) making the assay particularly suitable for large screening of total antioxidant activity in food samples.     

Application of a mobile electromagnetic sensing system (MESS) to assess cause and management of soil salinization in an irrigated cotton-growing field

Abstract. Generally, traditional soil surveys do not adequately account for the spatial variability of soil properties. Maps that are derived using these cursory soil data are likely to contain errors and thus make interpretation and soil management difficult. On the other hand quantitative methods of soil inventory at the field scale involve the design and adoption of sampling regimes and laboratory analysis that are time consuming and costly. In the latter case new technologies are required to efficiently sample and observe the soil in the field. This is particularly the case where soil salinization is prevalent, and detailed quantitative information for determining its cause is required. In this paper, a Mobile Electromagnetic Sensing System (MESS) is described and its application in an irrigated-cotton field, located in the lower Namoi valley in New South Wales, Australia. Results from the EM38 instrument were found to be correlated with the effective cation exchange capacity ( r ²= 0.81). This was related to variability in soil mineralogy across the field. In addition, differences in soil chemical and textural variables, measured along a transect and adjacent to water storage, were used to identify seepage areas near a water reservoir where soil salinization was evident.     

The Influence of Soil Properties on the Water Pollution (Nitrate,Phosphate and COD) Following a Single Application of Sewage Sludge to 70 Contrasting Agricultural Soils

The aim was to study the influence of soil properties on the leaching of nitrate, phosphate and organic matter (OM) following the application of sewage sludge to contrasting soils. Seventy agricultural soils from different parts of Spain were amended with sewage sludge (50 t dry weight ha⁻¹), and a controlled column study was developed. After 2, 4 and 6 months of incubation, distilled water, equivalent to an autumn rainfall event of 25 l m⁻² in Mediterranean environments, was applied and leachates collected and analysed: pH, electrical conductivity (EC), chemical oxygen demand (COD), phosphate and nitrate. The mean values of pH in the leachates after 2, 4 and 6 months were similar and close to the neutrality. The highest concentrations for the rest of the parameters analysed were found after 2 months of incubation and diminished for 4 and 6 months, especially COD. Soil pH and texture were the most relevant soil properties controlling the leaching of the analysed parameters. The OM mineralization seemed to be enhanced at high values of soil pH, thus increasing the nitrate and reducing the COD leaching. However, phosphate levels were reduced at high values of soil pH. In addition, leaching was promoted in sandy soils. Other soil properties influenced phosphate leaching being the equivalent calcium carbonate soil content as the most relevant. Soil organic carbon was negatively related to the EC and nitrate concentration in the leachates but resulting in a weak contribution compared with soil pH and texture. Concerns about nitrate pollution have been confirmed.