Bioaugmentation with butane-utilizing microorganisms to promote in situ cometabolic treatment of 1,1,1-trichloroethane and 1,1-dichloroethene

A field study was performed to evaluate the potential for in-situ aerobic cometabolism of 1,1,1-trichloroethane (1,1,1-TCA) through bioaugmentation with a butane enrichment culture containing predominantly two Rhodococcus sp. strains named 179BP and 183BP that could cometabolize 1,1,1-TCA and 1,1-dicholoroethene (1,1-DCE). Batch tests indicated that 1,1-DCE was more rapidly transformed than 1,1,1-TCA by both strains with 183BP being the most effective organism. This second in a series of bioaugmentation field studies was conducted in the saturated zone at the Moffett Field In Situ Test Facility in California. In the previous test, bioaugmentation with an enrichment culture containing the 183BP strain achieved short term in situ treatment of 1,1-DCE, 1,1,1-TCA, and 1,1-dichloroethane (1,1-DCA). However, transformation activity towards 1,1,1-TCA was lost over the course of the study. The goal of this second study was to determine if more effective and long-term treatment of 1,1,1-TCA could be achieved through bioaugmentation with a highly enriched culture containing 179BP and 183BP strains. Upon bioaugmentation and continuous addition of butane and dissolved oxygen and or hydrogen peroxide as sources of dissolved oxygen, about 70% removal of 1,1,1-TCA was initially achieved. 1,1-DCE that was present as a trace contaminant was also effectively removed ( 80%). No removal of 1,1,1-TCA resulted in a control test leg that was not bioaugmented, although butane and oxygen consumption by the indigenous populations was similar to that in the bioaugmented test leg. However, with prolonged treatment, removal of 1,1,1-TCA in the bioaugmented leg decreased to about 50 to 60%. Hydrogen pexoxide (H₂O₂) injection increased dissolved oxygen concentration, thus permitting more butane addition into the test zone, but more effective 1,1,1-TCA treatment did not result. The results showed bioaugmentation with the enrichment cultures was effective in enhancing the cometabolic treatment of 1,1,1-TCA and low concentrations of 1,1-DCE over the entire period of the 50-day test. Compared to the first season of testing, cometabolic treatment of 1,1,1-TCA was not lost. The better performance achieved in the second season of testing may be attributed to less 1,1-DCE transformation product toxicity, more effective addition of butane, and bioaugmentation with the highly enriched dual culture.     

Long-term changes in nitrogen deposition in Finland (1990–2006) monitored using the moss Hylocomium splendens

Nitrogen deposition in Finland was investigated on the basis of the nitrogen concentration in the forest moss, Hylocomium splendens, collected during heavy metal moss surveys carried out in 1990, 1995, 2000, and 2005/06. Significant regional differences were found in the nitrogen concentrations in mosses. The concentrations were the highest in the southern part of the country in all the surveys, with a decreasing trend on moving northwards. The mean concentrations in the surveys were 1.07%, 1.00%, 0.89% and 0.92%. In general, the concentrations in mosses reflected nitrogen deposition at the level of the whole country. However, they did not correlate very well with the modelled nitrogen deposition because of the high local variation in the nitrogen concentration in H. splendens. One reason for the high variation was the effect of the structure of the tree stand on nitrogen concentrations in H. splendens.     

Genotoxic effect of polycyclic aromatic hydrocarbons in the metropolitan area of Porto Alegre, Brazil, evaluated by Helix aspersa (Müller, 1774)

The purpose of this study was to biomonitor metropolitan areas of Porto Alegre (Brazil) for PAHs associated with atmospheric particles and check their effects on the DNA of the land mollusk Helix aspersa. The sampling sites are located in an urban area with heavy traffic: (i) Canoas, (ii) Sapucaia do Sul, and (iii) FIERGS/Porto Alegre. The samples were collected during a continuous period of 24 hours during 15 days using Stacked Filter Units (SFU) on polycarbonate filters (two separated size fractions: PM_10-2.5 and PM_<2.5). The concentrations of 16 major PAHs were determined according to EPA. Comet assay on H. aspersa hemolymph cells was chosen for genotoxicity evaluation. This evaluation shows that, in general, the smaller PM-size fractions (PM_<2.5) have the highest genotoxicity and contain higher concentrations of extractable organic matter. In addition, associations between chemical characteristics and PM carcinogenicity tend to be stronger for the smaller PM-size fractions.     

全氟辛烷磺酸盐(PFOS)在藻渣/小球藻上的吸附行为及机理

为了开发新型廉价生物吸附剂,以高效吸附去除水体中全氟辛烷磺酸盐(PFOS),对小球藻提取生物柴油后的藻渣吸附酸性水体中的PFOS进行了吸附行为及机理的研究。小球藻提取生物质柴油后,比表面积、孔容、孔径几乎没有变化;等电点由3.3降低至2.7;蛋白质含量由51.45%提高到57.35%。在酸性条件下(pH≤3),小球藻和藻渣对PFOS的吸附率均达到99%以上;随着pH值增加至7,二者的吸附去除率迅速降低,但仍保持在22%~26%。小球藻和藻渣对PFOS的最大吸附容量分别为353.69 mg/g和444.83 mg/g。Freundlich模型能较好地拟合二者对PFOS的吸附数据,表明为多层吸附,即小球藻以静电吸引的形式吸附PFOS阴离子,并疏水分配至所含蛋白质中;而藻渣中含量较高的蛋白质对PFOS的疏水性分配作用是导致藻渣吸附量增高的主要原因。     

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone # 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air.     

Breeding performance of blue tits (Cyanistes caeruleus) and great tits (Parus major) in a heavy metal polluted area

We compared heavy metal levels, calcium levels, breeding parameters and condition of nestling and adult Cyanistes caeruleus and Parus major along a heavy metal pollution gradient. Both species started laying earlier and showed inferior nestling growth and smaller fledging probability in the polluted areas, which are phenologically advanced in spring due to sparse forests. The major inter-specific difference in the responses was that the clutch size and hatching success were decreased in the polluted area in P. major, but not in C. caeruleus. Heavy metal profiles in nestling feces were relatively similar in the two species, though Ni and Pb levels were higher in C. caeruleus than in P. major. However, the latter species showed markedly higher fecal calcium concentrations. Lower calcium levels and higher levels of some heavy metals in C. caeruleus suggest that in Ca-deficient environments this species might be more susceptible to negative pollution effects than P. major.     

Using the optical properties of aerosols from the AERONET database to calculate surface solar UV-B irradiance in Córdoba, Argentina: Comparison with measurements

The main purpose of this study was to perform an evaluation of the particles’ optical parameters’ influence on surface solar UV-B (280–315 nm) irradiance in Córdoba, Argentina. To achieve this objective UV-B irradiance dataset, AERONET (AErosol RObotic NETwork) database, and TUV (Tropospheric Ultraviolet and Visible) model were used to analyze the effects of aerosols on surface irradiance on cloudless days during specific days of winter and spring of the period 1999–2006. Together with a direct observer, total irradiance (300–3000 nm) measurements were used as an ancillary tool to verify the cloudless condition. Every year, during this period, important reductions in surface irradiance are observed due to the aerosol load. Aerosols were incorporated in the model through the aerosol optical depth at 340 nm, the asymmetry parameter at 440 nm, and the single scattering albedo at 440 nm, all of them provided by AERONET Córdoba-CETT site. These factors vary from near to zero up to 1.4, from 0.56 up to 0.83 and from 0.43 up to 0.99, respectively. The behaviors of these factors along the year are analyzed considering the meteorology of Córdoba. When AERONET data are included in the TUV model they allow an accurate simulation of the UV-B irradiance, making the agreement with the experimental measurements substantially better. Only a small differences (±2%) remains, which can be attributed to diverse factors. As the AERONET site is 20 km away from the irradiance measurement site, these results show the regional character of the aerosols in Córdoba, although small contributions of urban aerosols are not discarded. An episode of high aerosol and pollutants laden due to fires in the surrounding hills is briefly analyzed. A set of additional studies are needed to describe comprehensively the characteristics and behavior of the Córdoba aerosols. Some of them are being already carried out.     

Impact of the global economic crisis on metal levels in particulate matter (PM) at an urban area in the Cantabria Region (Northern Spain)

Air pollution by particulate matter is well linked with anthropogenic activities; the global economic crisis that broke out in the last year may be a proper indicator of this close relationship. Some economic indicators show the regional effects of the crisis on the Cantabria Region. The present work aims to evaluate the impact of the economic crisis on PM10 levels and composition at the major city of the region, Santander. Some metals linked to anthropogenic activities were measured at Santander and studied by Positive Matrix Factorization; this statistical analysis allowed to identify three main factors: urban background, industrial and molybdenum-related factor. The main results show that the temporal trend of the levels of the industrial tracers found in the present study are well agree with the evolution of the studied economic indicators; nevertheless, the urban background tracers and PM10 concentration levels are not well correlated with the studied economic indicators.     

北京市交通道路空气中NO_x的污染现状及时空变化规律研究

基于2008年及2009年分4个季节对北京市3种类型道路(开阔型、交叉路口型和峡谷型)空气中的NOx的现场监测结果,分析了3种类型道路空气中NOx的污染现状和时空变化规律及影响因素。实验结果表明,昼间北京市各类型街道空气中NOx浓度呈早晚浓度高、中午浓度低的变化规律,NOx浓度随季节和车流量变化较明显。交通道路空气中NO占NOx的分担率高,且有较好的相关性,而NO2分担率较低,与NOx相关性较差。     

Assessment of the quality of the air in the city of Palermo through chemical and cell analyses on Pinus needles

The influence of air pollution on the chemical composition of Pinus sp. needles was examined in polluted and control sites in and around the city of Palermo (Sicily). The chemical composition of needles indicated the extent of contamination of the trees, which were cytologically examined. Cell analysis was carried out on pine samples, including needles and pollens, from 15 different locations. Biostructural and spectrophotometric tests were performed. In particular, concentrations of toxic (Cd, Pb) and non-toxic metals (Fe,Cu, Zn) were determined, as well as injury caused by their accumulation in the needles. The more highly urbanised areas showed higher concentrations of metals (Pb, Cu. Zn, Fe); only the concentrations of Cd and Mn turned out to be constant in all the sites. Cell analysis revealed displasic cells and secondary metabolite accumulations in trees from polluted sites. These changes observed were most likely caused by the toxic effect of pollutants.     

Influence of environmental factors on the response of a natural population of Daphnia magna (Crustacea: Cladocera) to spinosad and Bacillus thuringiensis israelensis in Mediterranean coastal wetlands

The present study was undertaken to assess the impact of a candidate mosquito larvicide, spinosad (8, 17 and 33 μg L⁻¹) on a field population of Daphnia magna under natural variations of water temperature and salinity, using Bti (0.16 and 0.50 μL L⁻¹) as the reference larvicide. Microcosms (125 L) were placed in a shallow temporary marsh where D. magna was naturally present. The peak of salinity observed during the 21-day observation period may have been partly responsible for the decrease of daphnid population density in all the microcosms. It is also probably responsible for the absence of recovery in the microcosms treated with spinosad which caused a sharp decrease of D. magna abundance within the first two days following treatment whereas Bti had no effect. These results suggest that it may be difficult for a field population of daphnids to cope simultaneously with natural (water salinity and temperature) and anthropogenic (larvicides) stressors.     

Embryo toxicity of pesticides and heavy metals to the ramshorn snail, Marisa cornuarietis (Prosobranchia)

An invertebrate embryo toxicity test with the ampullariid snail, Marisa cornuarietis, to assess the toxicity of pesticides and heavy metals recently was established. Snail embryos were treated with atrazine (100, 1000, 10 000, and 30 000 μg/L), imidacloprid (10 000, 25 000, and 50 000 μg/L), Ni²⁺ (0.1, 1, 10, and 100 μg/L) or Zn²⁺ (100, 200, 500, 1000, 2000, and 5000 μg/L). The effect of these substances was examined by monitoring the following endpoints: mortality, formation of tentacles and eyes, heart rate, hatching, and weight after hatching. Effects in term of a significant delay on the formation of both tentacles and eyes were found after treatment with 100 μg/L Ni²⁺ or 200 μg/L Zn²⁺. The heart rate was shown to significantly decrease at 25 000 μg/L imidacloprid or 1000 μg/L Zn²⁺. At 100 μg/L atrazine, 10 μg/L Ni²⁺, or 1000 μg/L Zn²⁺ a significant delay in hatching became visible. No significant mortality was observed for the tested concentrations of atrazine, imidacloprid, or Ni²⁺, while 5000 μg/L Zn²⁺ resulted in 100% mortality after 10 d. The weight of freshly hatched individuals remained unaffected in all treatments. On the basis of the lowest observed effect concentrations (LOECs) recorded, we could show the M. cornuarietis embryo toxicity test (MariETT) to react up to three orders of magnitude more sensitive (for metals) and at least one order of magnitude more sensitive (for the tested organics) than the established Danio rerio embryo test.     

Reproduction disturbances of Brachionus calyciflorus (rotifer) for the screening of environmental endocrine disrupters

Rotifers and especially the Brachionus calyciflorus species have already shown advantages (e.g. good sensitivity, simplicity, ecological relevance, short generation time) for the chronic toxicity assessment of water pollutants. In this study, the B. calyciflorus three-day test was evaluated on ethinylestradiol, nonylphenol and testosterone for the determination of endocrine disrupting (reproductive) effects. Reproduction (intrinsic rate of population increase) and sex ratio (males/females and mictic females/amictic females) were explored and discussed as suitable endpoints. B. calyciflorus has shown a fair sensitivity to detect reproductive disrupting effects after exposure to ethinylestradiol, nonylphenol and testosterone. Population growth (intrinsic rate of population increase, r) and the ratio ovigerous females/non-ovigerous females are both suitable endpoints, whereas the occurrence of males was not frequent enough to be used as endpoint.     

纺锤芽孢杆菌(Bacillus fusiformis)降解萘的特性及动力学

在前期研究中发现,纺锤芽孢杆菌(Bacillus fusiformis,BFN)可以用于降解水溶液的萘,为了解其降解过程,发现BFN菌生长量随着溶液中的萘的含量增加而提高。其中,萘的含量分别是30、50、100和200 mg/L时,BFN的生物量OD600值分别为0.057、0.081、0.126和0.193;降解培养基溶液COD的去除率分别为59.4%、65.3%、69.2%和70.6%,说明BFN菌在生长的过程中利用萘作为碳源。同时,动力学拟合发现,对不同含量萘的降解过程都符合一级降解动力学方程,且BFN菌的生长过程满足逻辑斯蒂方程。扫描电镜图表明,BFN菌在萘的存在下生长得更好。紫外光谱显示波长为276 nm的萘的吸收峰在降解后下降很多。红外光谱数据则表明,降解液中有2组新的吸收峰出现:一组出现在2 878、2 930和2 968 cm-1处,说明在萘的降解过程中有新的羧酸类生成;另一组出现在3 438、3 667和3 731 cm-1处有新的酚类物质生成。     

Impact of glyphosate on the development, fertility and demography of Chrysoperla externa (Neuroptera: Chrysopidae): Ecological approach

Few ecotoxicological studies have used life table analysis to evaluate the toxicity of pesticides on beneficial organisms. This study is the first report of the effect of the herbicide glyphosate on a predator insect, Chrysoperla externa, using a demographic approach. This predator is associated to soybean pests and has a potential role as a biological control agent in the Neotropical Region. The objective of this work was to evaluate the side-effects of glyphosate on the development, fertility and demography of C. externa, treated orally by ingestion of glyphosate-dipped eggs of Sitotroga cerealella in laboratory conditions. The data were analyzed using the age-stage, two-sex life table. Development from third larval instar to pupae and adult longevity were shorter in glyphosate-treatment than in the control. Adult pre-reproductive period was longer in glyphosate-treatment than in the control. Fecundity and fertility were deeply reduced, as well, being fertility greater affected. A high important reduction was registered in all population parameters. Most eggs from glyphosate-treated cohort looked abnormal, smaller than control, dehydrated and became black 2 d after oviposition. In addition, adults developed tumours in the abdomen region at 20 d after emergence, being the effect more drastic in females than males. It is beyond the scope of our study to speculate on the effects of this herbicide on C. externa field populations. However, it seems likely that populations under continuous use of glyphosate would be exposed at greater detrimental effects in the long term.     

A global assessment of chromium pollution using sperm whales (Physeter macrocephalus) as an indicator species

Chromium (Cr) is a well-known human carcinogen and a potential reproductive toxicant, but its contribution to ocean pollution is poorly understood. The aim of this study was to provide a global baseline for Cr as a marine pollutant using the sperm whale (Physeter macrocephalus) as an indicator species. Biopsies were collected from free-ranging whales around the globe during the voyage of the research vessel The Odyssey. Total Cr levels were measured in 361 sperm whales collected from 16 regions around the globe detectable levels ranged from 0.9 to 122.6 μg Cr g tissue⁻¹ with a global mean of 8.8 ± 0.9 μg g⁻¹. Two whales had undetectable levels. The highest levels were found in sperm whales sampled in the waters near the Islands of Kiribati in the Pacific (mean = 44.3 ± 14.4) and the Seychelles in the Indian Ocean (mean = 19.5 ± 5.4 μg g⁻¹). The lowest mean levels were found in whales near the Canary Islands (mean = 3.7 ± 0.8 μg g⁻¹) and off of the coast of Sri Lanka (mean = 3.3 ± 0.4 μg g⁻¹). The global mean Cr level in whale skin was 28-times higher than mean Cr skin levels in humans without occupational exposure. The whale levels were more similar to levels only observed previously in human lung tissue from workers who died of Cr-induced lung cancer. We conclude that Cr pollution in the marine environment is significant and that further study is urgently needed.     

Effects of bleached kraft mill effluents on the swimming activity of Monoporeia affinis (crustacea, amphipoda) lindström

The crustacean Monoporeia affinis Lindström was exposed to two different concentrations of bleached kraft mill effluent (BKME) containing, originally, 8.3 mg/g organic chlorine determined as adsorbable organic halogen (AOX). The swimming activity of the animals was recorded by pairs of infra-red sensitive photocells attached to 5.6 1 aquaria having a seawater inflow rate of 12 ml/min. The test sequence included a control phase, an exposure phase and a recovery phase. During the exposure phase the total swimming activity decreased in three of the four test aquaria containing effluent, indicating that the animals had retreated into the sediment. Total activity increased during the recovery phase and, in the case of the lower organic chlorine concentration, activity almost achieved the original control-phase level. Statistical differences in swimming activity changes during experiment were evaluated using ANOVA. Experimental methods are explained in detail.     

原位水解生成的羟基氧化铁凝聚吸附除磷效能与机制简

将不同摩尔比Fe³⁺与OH^-（[Fe³⁺]：[OH^-]=1：0、1：1、1：2和1：3）反应获得原位水解生成的羟基氧化铁（in situ FeO_xH_y）,研究了具有不同水解程度的羟基氧化铁对凝聚吸附除磷效能与机制。研究显示,In situ FeO_xH_y对磷的去除率随铁投量增大而升高,且均在中性pH范围内具有最佳除磷效果;在相同铁投量条件下,磷去除率随着[OH^-]：[Fe³⁺]的升高而降低;当体系碱度较低时（pH<6）,引入OH^-可促进Fe³⁺水解而提高除磷效果。4种羟基氧化铁均可在15 s内可快速吸附磷,且吸附过程符合准二级动力学模型;Freundlich模型均可很好地描述磷在4种羟基氧化铁表面的吸附行为。磷酸盐吸附后,In situ FeO_xH_y表面Zeta电位明显降低,且[Fe³⁺]：[OH^-]为1：0的羟基氧化铁降低最为显著。结合MINITEQ计算软件磷酸盐、铁盐形态分析结果显示,对于碱度较低的体系,通过投加一定量OH^-可促进Fe³⁺水解,进而使得其更易与水中H₂PO₄^-与HPO₄^2-结合,生成具有多核羟基的磷酸铁络合物,进而提高除磷效果。     

Potential genotoxic effects of melted snow from an urban area revealed by the Allium cepa test

The presence of well-known atmospheric pollutants is regularly screened for in large towns but knowledge about the effects of mixtures of different pollutants and especially their genotoxic potential is largely missing. Since falling snow collects pollutants from the air, melted snow samples could be suitable for evaluating potential genotoxicity. For this purpose the Allium cepa anaphase–telophase test was used to analyse melted snow samples from Belgrade, the capital city of Serbia. Samples of snow were taken at two sites, characterized by differences in pollution intensity, in three successive years. At the more polluted site the analyses showed a very high degree of both toxicity and genotoxicity in the first year of the study corresponding to the effects of the known mutagen used as the positive control. At the other site the situation was much better but not without warning signals. The results showed that standard analyses for the presence of certain contaminants in the air do not give an accurate picture of the possible consequences of urban air pollution because the genotoxic potential remains hidden. The A. cepa test has been demonstrated to be very convenient for evaluation of air pollution through analyses of melted snow samples.     

The influence of the North-Föhn on tracer organic compounds in ambient air PM10 at a pre-alpine site in Northern Italy

The ambient air in Northern Italy is characterised by relatively high PAH and PM₁₀ concentrations in relation to calm wind and intensive temperature inversions, especially during cold periods. These stagnant conditions are occasionally interrupted by North-Föhn events, which cause a drop in relative humidity and an increase in O₃ levels, indicating the mixing of local and free troposphere air flows. In this study the influence of the North-Föhn on concentrations of tracer organic compounds, including polycyclic aromatic hydrocarbons (PAHs), PM₁₀, O₃ and black carbon (BC) was studied during a North-Föhn event in November 2007. Large fluctuations in the concentration of these compounds, as well as changes in PM₁₀ composition due to daytime and night-time variations of local source emissions were observed. Although these events occur at low frequencies (6-10%) they can for short periods, strongly affect the regional air quality by quickly decreasing the concentrations of these tracer organic compounds.