Kinetics of the tropospheric formaldehyde loss onto mineral dust and urban surfaces

The kinetics of the heterogeneous reaction between gaseous HCHO and TiO₂/SiO₂ mineral coatings were investigated using a coated-wall flow tube to mimic HCHO loss on mineral aerosol and TiO₂ coated depolluting urban surfaces. The measured uptake kinetics were strongly enhanced when the flow tube was irradiated with 340–420 nm UV light with an irradiance of 1.45 mW cm^?2. The associated BET uptake coefficients ranged from (3.00 ± 0.45) × 10^?9 to (2.26 ± 0.34) × 10^?6 and were strongly dependent on HCHO initial concentration, relative humidity, temperature, and TiO₂ content in the mineral coating, which ranged from 3.5 to 32.5 ppbv, 6–70%, 278–303 K, and 1–100 %wt, respectively. The measured kinetics were well described using a Langmuir–Hinshelwood type formalism. The estimated uptake coefficients were used to discuss the importance of heterogeneous HCHO surface loss, in terms of deposition lifetimes, as compared to major homogeneous gas-phase losses such as OH reaction and photolysis. It is found that deposition may compete with gas-phase removal of HCHO in a dense urban environment if more than 10% of the urban surface is covered with TiO₂ treated material.     

City breathability and its link to pollutant concentration distribution within urban-like geometries

This paper is devoted to the study of pollutant concentration distribution within urban-like geometries. By applying efficiency concepts originally developed for indoor environments, the term ventilation is used as a measure of city “breathability”. It can be applied to analyse pollutant removal within a city in operational contexts. This implies the evaluation of the bulk flow balance over the city and of the mean age of air. The influence of building packing density on flow and pollutant removal is, therefore, evaluated using those quantities. Idealized cities of regular cubical buildings were created with packing density ranging from 6.25% to 69% to represent configurations from urban sprawl to compact cities. The relative simplicity of these arrangements allowed us to apply the Computational Fluid Dynamics (CFD) flow and dispersion simulations using the standard k–? turbulence model. Results show that city breathability within the urban canopy layer is strongly dependent from the building packing density. At the lower packing densities, the city responds to the wind as an agglomeration of obstacles, at larger densities (from about 44%) the city itself responds as a single obstacle. With the exception of the lowest packing density, airflow enters the array through lateral sides and leaves throughout the street top and flow out downstream. The air entering through lateral sides increases with increasing packing density.At the street top of the windward side of compact building configurations, a large upward flow is observed. This vertical transport reduces over short distance to turn into a downward flow further downstream of the building array. These findings suggest a practical way of identifying city breathability. Even though the application of these results to real scenarios require further analyses the paper illustrates a practical framework to be adopted in the assessment of the optimum neighbourhood building layout to minimize pollution levels.     

乌江梯级电站开发对大型底栖无脊椎动物群落结构和多样性的影响

为了解乌江贵州段的底栖动物资源现状以及梯级电站开发对底栖动物群落结构和多样性的影响,对18个断面的底栖动物进行了调查。底栖动物多样性通过Shannon Wiener多样性指数进行计算。结果显示：自然河段中,底栖动物物种丰富,以节肢动物占优势,物种丰富度和密度均以思南断面最高,生物多样性则以沿河二桥断面最高;群落类型复杂,环节动物 软体动物 节肢动物为优势群落,软体动物为群落中的优势类群。梯级水库的修建使底质环境差异变小,底栖动物物种丰度、密度和生物多样性降低,群落类型趋于简单,优势类群表现不明显,并且水库建成的年代越久,底栖动物的丰度、密度就越低,群落的组成类群就越少,物种组成以寡毛类和摇蚊类为主。研究表明,梯级电站的修建对底栖动物的物种组成、密度分布、多样性、群落类型等都造成了负面影响。〖     

A Generic Bio-Economic Farm Model for Environmental and Economic Assessment of Agricultural Systems

Bio-economic farm models are tools to evaluate ex-post or to assess ex-ante the impact of policy and technology change on agriculture, economics and environment. Recently, various BEFMs have been developed, often for one purpose or location, but hardly any of these models are re-used later for other purposes or locations. The Farm System Simulator (FSSIM) provides a generic framework enabling the application of BEFMs under various situations and for different purposes (generating supply response functions and detailed regional or farm type assessments). FSSIM is set up as a component-based framework with components representing farmer objectives, risk, calibration, policies, current activities, alternative activities and different types of activities (e.g., annual and perennial cropping and livestock). The generic nature of FSSIM is evaluated using five criteria by examining its applications. FSSIM has been applied for different climate zones and soil types (criterion 1) and to a range of different farm types (criterion 2) with different specializations, intensities and sizes. In most applications FSSIM has been used to assess the effects of policy changes and in two applications to assess the impact of technological innovations (criterion 3). In the various applications, different data sources, level of detail (e.g., criterion 4) and model configurations have been used. FSSIM has been linked to an economic and several biophysical models (criterion 5). The model is available for applications to other conditions and research issues, and it is open to be further tested and to be extended with new components, indicators or linkages to other models.     

What makes neighborhood different from home and city? Effects of place scale on place attachment

Several years ago Hidalgo and Hernandez reported a curvilinear, U-shaped, relationship between scale of place (apartment, neighborhood, city) and strength of attachment to the place. In this paper four studies are presented, carried out in four Central-European cities, that (1) confirmed the reported curvilinear relationship using five places (apartment, building, neighborhood, city district, city) in three out of four cities and for five items of the Place Attachment Scale, (2) revealed a consistent curvilinear, inverse U-shaped relationship between scale of place and percentage of variance of place attachment predicted by three groups of factors: physical (type of housing, size of building, upkeep and personalization of house precincts, etc.), social (neighborhood ties and sense of security in the residence place), and socio-demographic (age, education, gender, length of residence, family size), and (3) identified strength of direct and indirect effects of the three groups of predictors on attachment to the five types of places. The curvilinear relationship between place scale and place attachment was particularly strong in highly attractive cities and in those scale items that described people's emotional reactions to places whereas a linear relationship was obtained in the least attractive city and in the items that referred to sense of security, amount of control and knowledge of place. In all four cities the best predicted variable was attachment to middle ranges of the place scale (building and neighborhood). The overall best direct predictor of place attachment was neighborhood ties, followed by direct and indirect effects of length of residence, building size, and type of housing. In conclusion it is argued that the usual choice of predictors of place attachment is biased by researchers' interest in the middle scales of place (neighborhood) at the expense of other place scales. In the paper a claim is made that attachments to smaller (apartments, homes) and larger (city) scales of place along with their unique predictors deserve more attention from environmental psychologists.     

Frequency of micronuclei and of other nuclear abnormalities in erythrocytes of the grey mullet from the Mondego,Douro and Ave estuaries—Portugal

Fish are bioindicators of water pollution, and an increased rate of their erythrocyte nuclear morphological abnormalities (ENMAs)—and particularly of erythrocyte micronuclei (EMN)—is used as a genotoxicity biomarker. Despite the potential value of ENMAs and MN, there is scarce information about fish captured in Iberian estuaries. This is the case of the Portuguese estuaries of the Mondego, Douro and Ave, suffering from different levels of environmental stress and where chemical surveys have been disclosing significant amounts of certain pollutants. So, the aim of this study was to evaluate genotoxicants impacts and infer about the exposure at those ecosystems, using the grey mullet (Mugil cephalus) as bioindicator and considering the type and frequency of nuclear abnormalities of erythrocytes as proxies of genotoxicity. Sampling of mullets was done throughout the year in the important Mondego, Douro and Ave River estuaries (centre and north-western Portugal). The fish (total n?=?242) were caught in campaigns made in spring–summer and autumn–winter, using nets or fishing rods. The sampled mullets were comparable between locations in terms of the basic biometric parameters. Blood smears were stained with Diff-Quik to assess the frequencies of six types of ENMAs and MN (given per 1,000 erythrocytes). Some basic water physicochemical parameters were recorded to search for fluctuations matching the ENMAs. Overall, the most frequent nucleus abnormality was the polymorphic type, sequentially followed by the blebbed/lobed/notched, segmented, kidney shaped, vacuolated, MN and binucleated. The total average frequency of the ENMAs ranged from 73?‰ in the Mondego to 108?‰ in the Ave. The polymorphic type was typically ≥50 % of the total ENMAs, averaging about 51?‰, when considering all three estuaries. The most serious lesion—the MN—in fish from Mondego and Douro had a similar frequency (≈0.38?‰), which was significantly lower than that in the Ave (0.75?‰). No significant seasonal differences existed as to the MN rates and seasonal differences existed almost only in the Douro, with the higher values in AW. In general, the pattern of ENMAs frequencies was unrelated with the water physicochemical parameters. Considering the data for both the total ENMAs and for each specific abnormality, and bearing in mind that values of MN in fish erythrocytes >0.3?‰ usually reflect pollution by genotoxicants, it is suggested that mullets were likely being chronically exposed to such compounds, even in the allegedly less polluted ecosystem (Mondego). Moreover, data supported the following pollution exposure gradient: Mondego?<?Douro?<?Ave. The scenario and inferences nicely agree with the published data from chemical monitoring.     

Opportunities for Increasing Resilience and Sustainability of Urban Social–Ecological Systems: Insights from the URBES and the Cities and Biodiversity Outlook Projects

Urban futures that are more resilient and sustainable require an integrated social–ecological system approach to urban policymaking, planning, management, and governance. In this article, we introduce the Urban Biodiversity and Ecosystem Services (URBES) and the Cities and Biodiversity Outlook (CBO) Projects as new social–ecological contributions to research and practice on emerging urban resilience and ecosystem services. We provide an overview of the projects and present global urbanization trends and their effects on ecosystems and biodiversity, as a context for new knowledge generated in the URBES case-study cities, including Berlin, New York, Rotterdam, Barcelona, and Stockholm. The cities represent contrasting urbanization trends and examples of emerging science–policy linkages for improving urban landscapes for human health and well-being. In addition, we highlight 10 key messages of the global CBO assessment as a knowledge platform for urban leaders to incorporate state-of-the-art science on URBES into decision-making for sustainable and resilient urban development.     

Chemical and spectroscopic characterization of organic matter during the anaerobic digestion and successive composting of pig slurry

In this work, anaerobic digestion of pig slurry and successive composting of the digestate after centrifugation were studied by means of chemical analysis, FTIR and fluorescence spectroscopy as excitation–emission matrix (EEM). Chemical analysis highlighted the organic matter transformation occurring during the processes. A decrease of volatile solids and total organic carbon were observed in the digestate with respect to the fresh pig slurry as a consequence of the consumption of sugars, proteins, amino acids and fatty acids used by microorganisms as a C source. Water Extractable Organic Matter (WEOM) was obtained for all samples and fractionated into a hydrophilic and a hydrophobic fraction. The highest WEOM value was found in the pig slurry indicating a high content of labile organic C. The digestate centrifuged and the digestate composted showed lower hydrophilic and higher hydrophobic contents because of the decrease of labile C. Total phenolic content was lower in the digestate with respect to fresh pig slurry sample (36.7%) as a consequence of phenolic compounds degradation. The strong decrease of total reducing sugars in the digestate (76.6%) as compared to pig slurry confirmed that anaerobic process proceed mainly through consumption of sugars which represent a readily available energy source for microbial activity. FTIR spectra of pig slurry showed bands indicative of proteins and carbohydrates. A drop of aliphatic structures and a decrease of polysaccharides was observed after the anaerobic process along with the increase of the peak in the aromatic region. The composted substrate showed an increase of aromatic and a relative decrease of polysaccharides. EEM spectra provided tryptophan:fulvic-like fluorescence ratios which increased from fresh substrate to digestate because of the OM decompostion. Composted substrate presented the lowest ratio due to the humification process.     

The impact of infield biomass burning on PM levels and its chemical composition

In the South of Italy, it is common for farmers to burn pruning waste from olive trees in spring. In order to evaluate the impact of the biomass burning source on the physical and chemical characteristics of the particulate matter (PM) emitted by these fires, a PM monitoring campaign was carried out in an olive grove. Daily PM10 samples were collected for 1 week, when there were no open fires, and when biomass was being burned, and at two different distances from the fires. Moreover, an optical particle counter and a polycyclic aromatic hydrocarbon (PAH) analyzer were used to measure the high time-resolved dimensional distribution of particles emitted and total PAHs concentrations, respectively. Chemical analysis of PM10 samples identified organic and inorganic components such as PAHs, ions, elements, and carbonaceous fractions (OC, EC). Analysis of the collected data showed the usefulness of organic and inorganic tracer species and of PAH diagnostic ratios for interpreting the impact of biomass fires on PM levels and on its chemical composition. Finally, high time-resolved monitoring of particle numbers and PAH concentrations was performed before, during, and after biomass burning, and these concentrations were seen to be very dependent on factors such as weather conditions, combustion efficiency, and temperature (smoldering versus flaming conditions), and moisture content of the wood burned.     

Chemical Leasing business models and corporate social responsibility

Chemical Leasing is a service-oriented business model that shifts the focus from increasing sales volume of chemicals towards a value-added approach. Recent pilot projects have shown the economic benefits of introducing Chemical Leasing business models in a broad range of sectors. A decade after its introduction, the promotion of Chemical Leasing is still predominantly done by the public sector and international organizations. We show in this paper that awareness-raising activities to disseminate information on this innovative business model mainly focus on the economic benefits. We argue that selling Chemical Leasing business models solely on the grounds of economic and ecological considerations falls short of branding it as a corporate social responsibility initiative, which, for this paper, is defined as a stakeholder-oriented concept that extends beyond the organization’s boundaries and is driven by an ethical understanding of the organization’s responsibility for the impact of its business activities. For the analysis of Chemical Leasing business models, we introduce two case studies from the water purification and metal degreasing fields, focusing on employees and local communities as two specific stakeholder groups of the company introducing Chemical Leasing. The paper seeks to demonstrate that Chemical Leasing business models can be branded as a corporate social responsibility initiative by outlining the vast potential of Chemical Leasing to improve occupational health and safety and to strengthen the ability of companies to protect the environment from the adverse effects of the chemicals they apply.