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1.

Among the wide range of compounds reaching the soil are the veterinary antimicrobials. Since no regulations regarding acceptable levels of drug concentrations in the environment exist, monitoring tests, particularly concerning soils, are carried out very rarely. This study presents a preliminary assessment of the contamination of agricultural soils in Northern Poland with seven antimicrobial veterinary medicines which has never been carried out before. Veterinary drugs were detected in 54% of the examined soil samples; the most commonly detected drugs were sulfonamides and trimethoprim. The highest indicated concentrations refer to enrofloxacin (57.0 μg kg?1) and trimethoprim (47.8 μg kg?1). The presence of these target drugs in the soil environment confirms the need for further monitoring studies. The analytical methods developed in this study are an excellent tool to achieve this goal and allow an estimation of the risk connected with the presence of veterinary antimicrobials in soils.

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2.
To investigate the effect of temperature on effective diffusion coefficients and retardation factors for Zn and Cd, combined diffusion and sequential extraction analyses were conducted at 15 ˚C and 55 ˚C. The effective diffusion coefficients of the metals increased up to ten times according to the increased temperature. On the other hand, the effect of temperature on the retardation factor depended on the retention mechanisms of the metals. The distribution coefficient for Zn, which was mainly partitioned in the carbonate phase, increased up to two times with the increase in temperature. On the other hand, the distribution coefficient for Cd, which was mainly partitioned in the exchangeable phase, was hardly affected by the temperature change. Results of combined diffusion and sequential extraction analysis showed that the effect of temperature on the heavy metals’ (Zn and Cd) migration through the compacted natural clay was influenced by the combined effects of the diffusion coefficient and the retardation factor. Additionally, we could also observe the change in retention mechanism for the metals with the change in pore water concentration.  相似文献   
3.
The use of molecular tools, principally qPCR, versus traditional culture-based methods for quantifying microbial parameters (e.g., Fecal Indicator Organisms) in bathing waters generates considerable ongoing debate at the science–policy interface. Advances in science have allowed the development and application of molecular biological methods for rapid (~2 h) quantification of microbial pollution in bathing and recreational waters. In contrast, culture-based methods can take between 18 and 96 h for sample processing. Thus, molecular tools offer an opportunity to provide a more meaningful statement of microbial risk to water-users by providing near-real-time information enabling potentially more informed decision-making with regard to water-based activities. However, complementary studies concerning the potential costs and benefits of adopting rapid methods as a regulatory tool are in short supply. We report on findings from an international Working Group that examined the breadth of social impacts, challenges, and research opportunities associated with the application of molecular tools to bathing water regulations.  相似文献   
4.
The socio-cultural assessment of ecosystem services has been proposed as a promising tool for eliciting people’s preferences towards ecosystem services. Despite an increasing integration of the socio-cultural perspective in ecosystem service research, little knowledge exists about linkages between landscape and the socio-cultural values people assign to ecosystem services. This paper combines a socio-cultural valuation approach with the use of landscape pictures to analyse and compare people’s perceived importance of the provisioning, regulating, and cultural ecosystem service categories across three landscape types (i.e. larch meadows, spruce forests, and hay meadow). A survey with 470 tourists visiting the region of South Tyrol (Italy) was conducted to link people’s perceived importance to their socio-demographic background and to the landscape types explored. The results show that regulating ecosystem services are preferred over provisioning and cultural services, whereby environmental awareness is found to be more influential than formal education levels regarding the perceived importance of regulating services. The results further demonstrate that cultural background is an important driver in determining people’s perceived importance of cultural services. The underlying landscape types, however, exert an even stronger influence on people’s socio-cultural valuation of ecosystem service categories. This finding suggests that the focus of most ecosystem services assessments on the study area as a whole risks mistakenly attributing differences in people’s socio-cultural values to socio-demographic characteristics only. A better knowledge of the spatial integration of socio-cultural values, however, could help with anticipating the consequences of changes in the landscape and provide better guidance for future landscape planning.  相似文献   
5.
Kim do H  Mulholland JA  Ryu JY 《Chemosphere》2007,67(9):S135-S143
Polychlorinated naphthalenes (PCNs) formed along with dibenzo-p-dioxin and dibenzofuran products in the slow combustion of dichlorophenols (DCPs) at 600 degrees C were identified. Each DCP reactant produced a unique set of PCN products. Major PCN congeners observed in the experiments were consistent with products predicted from a mechanism involving an intermediate formed by ortho-ortho carbon coupling of phenoxy radicals; polychlorinated dibenzofurans (PCDFs) are formed from the same intermediate. Tautomerization of the intermediate and H2O elimination produces PCDFs; alternatively, CO elimination to form dihydrofulvalene and fusion produces naphthalenes. Only trace amounts of tetrachloronaphthalene congeners were formed, suggesting that the preferred PCN formation pathways from chlorinated phenols involve loss of chlorine. 3,4-DCP produced the largest yields of PCDF and PCN products with two or more chlorine substituents. 2,6-DCP did not produce tri- or tetra-chlorinated PCDF or PCN congeners. It did produce 1,8-DCN, however, which could not be explained.  相似文献   
6.
The De?le River in Northern France experienced serious contamination from the metallurgical industry, especially from the smelter Metaleurop prior to 2003. In 2002 the surface sediments were collected from the bed of the river around 10 km above and 10 km below the smelter. Total mercury (HgT) and methylmercury (MeHg) concentrations exceeded the background value of 0.1 mg kg(-1). The average concentrations were 19.67 ± 1.02 mg kg(-1) and 10.88 ± 1.08 μg kg(-1), respectively. In 2003 the sediment core samples were collected at two different sites near the factory for survey depth profiles of Hg contamination. The concentrations of HgT and MeHg in sediment cores varied from 10.47 to 259.44 mg kg(-1) and from 3.24 to 82.61 μg kg(-1), respectively. The concentration of total mercury was significantly correlated with the methylmercury concentration in the sediment below a depth of 23.5 cm (R(2) = 0.81, p < 0.01). This may suggest that the production of MeHg is directly related to the HgT concentration. Nevertheless the MeHg/HgT ratio in the upper part of the sediment core was higher than that in the lower part. This suggests that HgT and MeHg may have been co-deposited together. However, the methylmercury production takes place in the surface sediment by microorganisms. The strong correlation observed between MeHg and acid volatile sulfides (AVS) suggests that MeHg variability is associated with the bacterial activity (presence of AVS).  相似文献   
7.
8.
In order to determine the distribution and enable the elimination of quinalphos, a popular active pesticide compound used in the Mekong Delta, an experiment was set up in a rice-fish integration system in Can Tho City, Vietnam. Fish was stocked into the field when the rice was two-months old. Quinalphos was applied twice in doses of 42.5 g per 1000 m2. Water, fish and sediment samples were collected at time intervals and analyzed by a Gas Chromatography Electron Capture Detector system. The results show that quinalphos residues in fish muscles were much higher than those of the water and the bioconcentration factor (logBCF) was above 2 for the fish. The half-life of first and second quinalphos applications were 12.2 and 11.1 days for sediment, 2.5 and 1.1 days for silver barb, 1.9 and 1.3 days for common carp, and 1.1 and 1.0 days for water, respectively.  相似文献   
9.
Among the effects of global warming, sea level rise (SLR) and severe typhoons pose the greatest threat to the stability of human settlements along coastlines. Therefore, countermeasures must be developed to mitigate the influences of strong typhoons and persistent SLR for coastal protection. This study assesses climate change impacts on coastal erosion, especially in two projected SLR scenarios of RCP2.6 and RCP8.5. The results show that SLR and severe typhoons lead to the increase of coastal erosion, beach lowering and scour. Moreover, as in projected SLR scenarios, average waves in high tide can cause severe soil erosion at inner slopes and lead to dyke failure by 2060. The paper highlights the need for additional countermeasures to protect the coast of Hai Hau district against SLR and severe typhoons. Among the alternatives available for countering these threats, applying soil stabilization and soil improvement combined with geosynthetics are promising strategies for coastal structures. Hybrid structures can be used with earth reinforcement and soil improvement. Additionally, the paper emphasizes the importance of multiple protective adaptations, including geosynthetics and ecological engineering measures against climate change-induced severe erosion on the coast of Hai Hau district.  相似文献   
10.
Membrane fouling is a major concern for the optimization of membrane bioreactor (MBR) technologies. Numerous studies have been led in the field of membrane fouling control in order to assess with precision the fouling mechanisms which affect membrane resistance to filtration, such as the wastewater characteristics, the mixed liquor constituents, or the operational conditions, for example. Worldwide applications of MBRs in wastewater treatment plants treating all kinds of influents require new methods to predict membrane fouling and thus optimize operating MBRs. That is why new models capable of simulating membrane fouling phenomenon were progressively developed, using mainly a mathematical or numerical approach. Faced with the limits of such models, artificial neural networks (ANNs) were progressively considered to predict membrane fouling in MBRs and showed great potential. This review summarizes fouling control methods used in MBRs and models built in order to predict membrane fouling. A critical study of the application of ANNs in the prediction of membrane fouling in MBRs was carried out with the aim of presenting the bottlenecks associated with this method and the possibilities for further investigation on the subject.  相似文献   
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