Organochlorine pollution in tropical rivers (Guadeloupe): role of ecological factors in food web bioaccumulation

Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of β-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to β-HCH.     

新型水处理活性炭选型技术

活性炭依其原料不同、生产工艺不同,而有不同的吸附性能.使用简易的活性炭选型方法,可以减少应用测试时的备选炭型,从而大大降低活性炭水处理技术的运行成本.以碘值、甲基蓝值、苯酚值和丹宁酸值4种吸附容量性能指标为依据的活性炭选型技术,可以有效地预测活性炭对于水中各种大小不同污染物的去除能力.BET测试结果证明了这4项指标数据对于活性炭孔径分布预测的准确性.2,4-二氯苯酚和腐殖酸等目标化合物的吸附容量实验结果也都验证了这4项指标的预测功用,说明这种简便的活性炭选型技术有着广泛的应用价值.     

环境水体微污染有机物及其去除技术研究进展

水体有机污染物因其生物毒性对人体健康和生态环境造成了严重的危害。随着环保技术的发展,高浓度有机污染物已得到很好的去除。检测水平的不断提高使微量有机污染物日益受到广泛关注。为了深入地研究微污染有机物及其去除技术,对微污染有机物的种类、性质和危害进行了详细阐述,并综述了国内外生物法、膜处理技术、高级氧化技术、吸附技术对微污染有机物的去除效果,总结了各种技术的优缺点。     

Fading of Selected Drapery Fabrics by Air Pollutants

A statistically designed laboratory study to assess both direct and synergistic effects of air pollutants and other environmental factors on six different classes of materials was recently completed.¹ One of the material classes was dyed textile fabrics. Drapery fabrics were specifically selected because they are economically important, are designed to have a fairly long life, and are subject to atmospheric fading. In fact, fading, whether caused by sunlight, pollution or both, frequently limits the useful life of draperies.     

Sorption of 4-n-nonylphenol, 4-n-octylphenol,and 4-tert-octyphenol on cyclodextrin polymers

Environmental Science and Pollution Research - Alkylphenols are industrial pollutants commonly present in wastewater. They are difficult to eliminate by conventional treatment processes, ending up...     

Abiotic degradation of chlorinated ethanes and ethenes in water

INTRODUCTION: Chlorinated ethanes and ethenes are among the most frequently detected organic pollutants of water. Their physicochemical properties are such that they can contaminate aquifers for decades. In favourable conditions, they can undergo degradation. In anaerobic conditions, chlorinated solvents can undergo reductive dechlorination. DEGRADATION PATHWAYS: Abiotic dechlorination is usually slower than microbial but abiotic dechlorination is usually complete. In favourable conditions, abiotic reactions bring significant contribution to natural attenuation processes. Abiotic agents that may enhance the reductive dechlorination of chlorinated ethanes and ethenes are zero-valent metals, sulphide minerals or green rusts. OXIDATION: At some sites, permanganate and Fenton's reagent can be used as remediation tool for oxidation of chlorinated ethanes and ethenes. SUMMARY: Nanoscale iron or bimetallic particles, due to high efficiency in degradation of chlorinated ethanes and ethenes, have gained much interest. They allow for rapid degradation of chlorinated ethanes and ethenes in water phase, but they also give benefit of treating dense non-aqueous phase liquid.     

Cigarette butt littering consequences: a study of pollution rate on beaches and urban environments

Cigarette butts are hazardous wastes that are not properly discarded by most smokers. They are one of the most abundant litters in the environment and a threat to various organisms because they leak numerous pollutants. This study aimed to assess the distribution of cigarette butts in a coastal city south of the Caspian Sea in Mazandaran Province, Iran. Observations were performed using the visual survey technique based on standardized protocol. The results showed 11,261 littered cigarette butts in 15 studied urban areas ( an average of 0.306 units per square meter). Also, the average density of littered cigarette butts on the studied beaches was 0.106 per square meter. The littered cigarette butts had significant spatial variation, and the number of counts was 135 to 2090. The land-use has a significant effect on the density of littered cigarette butts due to its population density. The inquiry’s index demonstrated that 33.3% of the studied urban areas are high pollution and severe pollution, while all beaches are high and severe. Therefore, a significant focus must be considered to reduce cigarette butts littering due to the collection problems and challenges of cigarette butt management. Because the pollution on the beaches is higher than in urban areas, improving waste management services and establishing a regular cleaning program are essential.

     

Spatial variability of sediment ecotoxicity in a large storm water detention basin

Detention basins are valuable facilities for urban storm water management, from both the standpoint of flood control and the trapping of pollutants. Studies performed on storm water have shown that suspended solids often constitute the main vector of pollutants (heavy metals, polycyclic aromatic hydrocarbon (PAH), etc.). In order to characterise the ecotoxicity of urban sediments from storm water detention basins, the sediments accumulated over a 6-year period were sampled at five different points through the surface of a large detention basin localised in the east of Lyon, France. A specific ecotoxicological test battery was implemented on the solid phase (raw sediment) and the liquid phase (interstitial water of sediments). The results of the study validated the method formulated for the ecotoxicological characterization of urban sediments. They show that the ecotoxicological effect of the sediments over the basin is heterogeneous and greater in areas often flooded. They also show the relationship between, on one hand, the physical and chemical characteristics of the sediments and, on the other hand, their ecotoxicity. Lastly, they contribute to a better understanding of the dynamics of the pollution close to the bottom of detention basins, which can be useful for improving their design. The results of this research raise particularly the issue of using oil separators on the surface of detention basins.     

Intercontinental transport of aerosols and photochemical oxidants from Asia and its consequences

The intercontinental transport of aerosols and photochemical oxidants from Asia is a crucial issue for air quality concerns in countries downwind of the significant emissions and concentrations of pollutants occurring in this important region of the world. Since the lifetimes of some important pollutants are long enough to be transported over long distance in the troposphere, regional control strategies for air pollution in downwind countries might be ineffective without considering the effects of long-range transport of pollutants from Asia. Field campaigns provide strong evidence for the intercontinental transport of Asian pollutants. They, together with ground-based observations and model simulations, show that the air quality over parts of North America is being affected by the pollutants transported from Asia. This paper examines the current understanding of the intercontinental transport of gases and aerosols from Asia and resulting effects on air quality, and on the regional and global climate system.     

An experimental study of the horizontal and vertical distribution of ozone over Athens

In this study, we present measurements of ozone (O₃) concentrations both on the surface and aloft, taken at sites appropriately located to give information about the effect of the local flows, such as the sea breeze circulation, on the air quality of Athens. Profiles of O₃ and other meteorological parameters of the atmospheric boundary layer were obtained at a location in the center of Athens. Surface measurements of O₃ were conducted in a number of other locations which included the shoreline and an island. The measurements confirmed well known models for the effect of sea breeze on photochemical pollutants and the diurnal variation of O₃ in the evolving atmospheric boundary layer and showed that pollutants released in the evening and early morning hours are advected offshore where they generate O₃ which in turn is advected back to the city by the sea breeze. They also showed that Athens pollutants are found in considerable concentrations in Aegina and outside the main basin to the north. The results of this study demonstrate the need to take into account advection patterns in any attempt to formulate pollution abatement strategies for sites with strong local circulations such as the Athens basin.     

Chlorinated fatty acids - Environmental pollutants with intriguing properties

The chlorine bound in chlorinated fatty acids (ClFAs) have been concluded to contribute to a major part of the extractable organically bound chlorine found in fish and other aquatic biota. Despite ClFAs giving rise to toxic effects they appear not to be recognised as “xenobiotic” compounds by the organism. They are readily accumulated via food and incorporated into complex lipids to approximately the same extent as unchlorinated fatty acids and may thus be transferred from prey to predator in the food chain. The ClFAs thus diverge from traditional environmental pollutants, such as PCBs, in several aspects and their fate in the environment can not be predicted by conventional risk assessment methods.     

Native plant species suitable as bioindicators and biomonitors for airborne fluoride

For 30-40 years airborne fluoride, usually in the form of HF or SiF4, was one of the most important and damaging air pollutants affecting forests, crops and natural vegetation. It is much more toxic than most other air pollutants such as O3 or SO2 because injury to the most sensitive species begins when they are exposed to a concentration below 1 ppb (ca. 0.8 microg m(-3)) for a 1- to 3-day period. The long-term threshold concentration is around 0.25-0.30 microg m(-3). Higher concentrations and longer durations of exposure induce much more rapid and extensive injury. However, there is a difference in sensitivity between the most and least sensitive species of around 2-3 orders of magnitude and most species possess a degree of resistance. Dramatic improvements in engineering technology have greatly reduced emissions but because of the high toxicity, cases of vegetation injury are still common, even in developed countries, and cases involving litigation still occur. Therefore there is a continuing need for bioindicators and biomonitoring of fluorides, so this paper reviews the subject, drawing attention to the strengths and limitations of the techniques. Visible symptoms are described and illustrated and tables of relative sensitivity are given and their limitations discussed. Finally, examples of biomonitoring in Europe and the USA are presented.     

Personal exposure of children to air pollution

Changes over recent decades in outdoor concentrations of air pollutants are well documented. However, the impacts of air pollution on an individual's health actually relate not to these outdoor concentrations but to their personal exposure in the different locations in which they spend time. Assessing how personal exposures differ from outdoor concentrations, and how they have changed over recent decades, is challenging. This review focuses on the exposure of children, since they are a particularly sensitive group. Much of children's time is spent indoors, and childhood exposure is closely related to concentrations in the home, at school, and in transport. For this reason, children's personal exposures to air pollutants differ significantly from both those of adults and from outdoor concentrations. They depend on a range of factors, including urbanisation, energy use, building design, travel patterns, and activity profiles; analysis of these factors can identify a wider range of policy measures to reduce children's exposure than direct emission control. There is a very large variation in personal exposure between individual children, caused by differences in building design, indoor and outdoor sources, and activity patterns. Identifying groups of children with high personal exposure, and their underlying causes, is particularly important in regions of the world where emissions are increasing, but there are limited resources for environmental and health protection. Although the science of personal exposure assessment, with the associated measurement and modelling techniques, has developed to maturity in North America and western Europe over the last 50 years, there is an urgent need to apply this science in other parts of the world where the effects of air pollution are now much more serious.     

Fractal and multifractal approach to environmental pollution

A few case studies will be presented involving both radioactive and chemical pollution at small, medium, and large space-time scales. Reported are recent advances in the field of environmental pollution involving the use of fractals and multifractals. The mathematical tools proposed here may offer new perspectives for investigating many of the problems of nonlinear variability which commonly arise when dealing with pollutants, such as the presence of outliers and the sparseness of the sampling networks. They may also lead to a simplification of the models adopted for studying natural phenomena, thanks to a scaling approach. Finally, they may provide parameters whose values are directly related to the nonlinear dynamics involved in the pollutant distribution in the environment which, in turn, may be relevant for computer simulation and epidemiological or risk assessment purposes.     

Prioritizing research for trace pollutants and emerging contaminants in the freshwater environment

Organic chemicals have been detected at trace concentrations in the freshwater environment for decades. Though the term trace pollutant indicates low concentrations normally in the nanogram or microgram per liter range, many of these pollutants can exceed an acceptable daily intake (ADI) for humans. Trace pollutants referred to as emerging contaminants (ECs) have recently been detected in the freshwater environment and may have adverse human health effects. Analytical techniques continue to improve; therefore, the number and frequency of detections of ECs are increasing. It is difficult for regulators to restrict use of pollutants that are a human health hazard; scientists to improve treatment techniques for higher priority pollutants; and the public to modify consumption patterns due to the vast number of ECs and the breadth of literature on the occurrence, use, and toxicity. Hence, this paper examines literature containing occurrence and toxicity data for three broad classes of trace pollutants and ECs (industrials, pesticides, and pharmaceuticals and personal care products (PPCPs)), and assesses the relevance of 71 individual compounds. The evaluation indicates that widely used industrials (BPF) and PPCPs (AHTN, HHCB, ibuprofen, and estriol) occur frequently in samples from the freshwater environment but toxicity data were not available; thus, it is important to establish their ADI. Other widely used industrials (BDE-47, BDE-99) and pesticides (benomyl, carbendazim, aldrin, endrin, ethion, malathion, biphenthrin, and cypermethrin) have established ADI values but occurrence in the freshwater environment was not well documented. The highest priority pollutants for regulation and treatment should include industrials (PFOA, PFOS and DEHP), pesticides (diazinon, methoxychlor, and dieldrin), and PPCPs (EE2, carbamazepine, βE2, DEET, triclosan, acetaminophen, and E1) because they occur frequently in the freshwater environment and pose a human health hazard at environmental concentrations.     

Using nanoscale zero-valent iron for the remediation of polycyclic aromatic hydrocarbons contaminated soil

The sites contaminated with recalcitrant organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) with multiple benzene rings, are colossal and ubiquitous environmental problems. They are relatively nonbiodegradable and mutagenic, and 16 of them are listed in the U.S. Environment Protection Agency priority pollutants. Thus, the efficient and emerging remediation technologies for removal of PAHs in contaminated sites have to be uncovered urgently. In this decade, the zero-valent iron (ZVI) particles have been used successfully in the laboratory, pilot, and field, such as degradation of chlorinated hydrocarbons and remediation of the other pollutants. Nevertheless, as far as we know, little research has investigated for soil remediation; this study used nanoscale ZVI particles to remove pyrene in the soil. The experimental variables were determined, including reaction time, iron particle size, and dosage. From the results, both the micro- and nanoscales of ZVI were capable of removing the target compound in soil, but the higher removal efficiencies were by nanoscale ZVI because of the massive specific surface area. The optimal operating conditions to attain the best removal efficiency of pyrene were obtained while adding nanoscale ZVI 0.1 g/g soil within 60 min and 150 rpm of mixing. Thus, nanoscale ZVI has proved to be a promising remedy for PAH-contaminated soil in this study, as well as an optimistically predictable application for additional pilot and field studies.     

石油化工废水处理技术研究进展

石油化工废水组成复杂、浓度高、毒性强和难降解,对环境危害大.概括介绍了国内外石油化工废水的主要处理方法如物化法、化学法和生化法,并评述了各种处理方法的适用条件和处理效果,总结了各种处理方法的优缺点.最后,提出推行清洁生产,开展废水资源化,并用高效的末端治理方法处理废水,是石油化工行业水污染控制的出路.     

Pollution and probabilistic human health risk assessment of potentially toxic elements in the soil-water-plant system in the Bolkar mining district,Niğde,south-central Turkey

Environmental Science and Pollution Research - Globally, potentially toxic elements (PTEs) are regarded as an important group of pollutants for the wider environment because of their intrinsic...     

Using Nanoscale Zero-Valent Iron for the Remediation of Polycyclic Aromatic Hydrocarbons Contaminated Soil

Abstract

The sites contaminated with recalcitrant organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) with multiple benzene rings, are colossal and ubiquitous environmental problems. They are relatively nonbiodegradable and mutagenic, and 16 of them are listed in the U.S. Environment Protection Agency priority pollutants. Thus, the efficient and emerging remediation technologies for removal of PAHs in contaminated sites have to be uncovered urgently. In this decade, the zero-valent iron (ZVI) particles have been used successfully in the laboratory, pilot, and field, such as degradation of chlorinated hydrocarbons and remediation of the other pollutants. Nevertheless, as far as we know, little research has investigated for soil remediation; this study used nanoscale ZVI particles to remove pyrene in the soil. The experimental variables were determined, including reaction time, iron particle size, and dosage. From the results, both the micro- and nanoscales of ZVI were capable of removing the target compound in soil, but the higher removal efficiencies were by nanoscale ZVI because of the massive specific surface area. The optimal operating conditions to attain the best removal efficiency of pyrene were obtained while adding nanoscale ZVI 0.1 g/g soil within 60 min and 150 rpm of mixing. Thus, nanoscale ZVI has proved to be a promising remedy for PAH-contaminated soil in this study, as well as an optimistically predictable application for additional pilot and field studies.