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691.
Land use is known to alter the nature of land–water interactions, but the potential effects of widespread forest management on headwaters in boreal regions remain poorly understood. We evaluated the importance of catchment land use, land cover, and local stream variables for macroinvertebrate community and functional trait diversity in 18 boreal headwater streams. Variation in macroinvertebrate metrics was often best explained by in-stream variables, primarily water chemistry (e.g. pH). However, variation in stream variables was, in turn, significantly associated with catchment-scale forestry land use. More specifically, streams running through catchments that were dominated by young (11–50 years) forests had higher pH, greater organic matter standing stock, higher abundance of aquatic moss, and the highest macroinvertebrate diversity, compared to streams running through recently clear-cut and old forests. This indicates that catchment-scale forest management can modify in-stream habitat conditions with effects on stream macroinvertebrate communities and that characteristics of younger forests may promote conditions that benefit headwater biodiversity.  相似文献   
692.
This study was conducted to assess the merits and limitations of various high-pressure membranes, tight nanofiltration (NF) membranes in particular, for the removal of trace organic compounds (TrOCs). The performance of a low-pressure reverse osmosis (LPRO) membrane (ESPA1), a tight NF membrane (NF90) and two loose NF membranes (HL and NF270) was compared for the rejection of 23 different pharmaceuticals (PhACs). Efforts were also devoted to understand the effect of adsorption on the rejection performance of each membrane. Difference in hydrogen bond formation potential (HFP) was taken into consideration. Results showed that NF90 performed similarly to ESPA1 with mean rejection higher than 95%. NF270 outperformed HL in terms of both water permeability and PhAC rejection higher than 90%. Electrostatic effects were more significant in PhAC rejection by loose NF membranes than tight NF and LPRO membranes. The adverse effect of adsorption on rejection by HL and ESPA1 was more substantial than NF270 and NF90, which could not be simply explained by the difference in membrane surface hydrophobicity, selective layer thickness or pore size. The HL membrane had a lower rejection of PhACs of higher hydrophobicity (log D>0) and higher HFP (>0.02). Nevertheless, the effects of PhAC hydrophobicity and HFP on rejection by ESPA1 could not be discerned. Poor rejection of certain PhACs could generally be explained by aspects of steric hindrance, electrostatic interactions and adsorption. High-pressure membranes like NF90 and NF270 have a high promise in TrOC removal from contaminated water.
  相似文献   
693.
This study was undertaken to evaluate the effectiveness of several household practices (washing with water or acidic, alkaline, and oxidizing solutions, and peeling) in minimizing pesticide residue contamination of tomatoes, as well as the impact on the quality of the treated fruit. Tests were performed using two systemic fungicides (azoxystrobin and difenoconazole) and one contact fungicide (chlorothalonil). Solid-liquid extraction with low temperature partition (SLE/LTP) and liquid-liquid extraction with low temperature partition (LLE/LTP) were used to prepare the samples for pesticides determination by gas chromatography. Washing the tomatoes with water removed approximately 44% of chlorothalonil, 26% of difenoconazole, and 17% of azoxystrobin. Sodium bicarbonate (5%) and acetic acid (5%) solutions were more efficient, removing between 32 and 83% of the residues, while peeling removed from 68 to 88% of the pesticides. The washing solutions altered some fruit quality parameters, including acidity and chroma, and also caused weight loss. Acetic acid (0.15 and 5%) and hypochlorite (1%) solutions had the greatest effect on these parameters.  相似文献   
694.
The main limitation of a conventional palm oil mill effluent (POME) ponding system lies in its inability to completely decolourise effluent. Decolourisation of effluent is aesthetically and environmentally crucial. However, determination of the optimum process parameters is becoming more complex with the increase of the number of coagulants and responses. The primary objective of this study is to determine the optimum polymeric coagulant in the coagulation–flocculation process of palm oil mill effluent by considering all output responses, namely lignin–tannin, low molecular mass coloured compounds (LMMCC), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), pH and conductivity. Here, multiple-objective optimisation on the basis of ratio analysis (MOORA) is employed to discretely measure multiple response characteristics of five different types of coagulants as a function of assessment value. The optimum coagulant is determined based on the highest assessment value and was identified as QF25610 (cationic polyacrylamide). On the other hand, the lowest assessment value was represented by AN1800 (anionic polyacrylamide). This study highlights the simplicity of MOORA approach in handling various input and output parameters, and it may be useful in other wastewater treatment processes as well.  相似文献   
695.
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   
696.
Triclocarban (TCC) is an antibacterial agent found in pharmaceuticals and personal care products (PPCP). It is potentially bioaccumulative and an endocrine disruptor, being classified as a contaminant of emerging concern (CEC). In normal uses, approximately 96% of the used TCC can be washed down the drain going into the sewer system and eventually enter in the aquatic environment. UV photolysis can be used to photodegrade TCC and ecotoxicity assays could indicate the photodegradation efficiency, since the enormous structural diversity of photoproducts and their low concentrations do not always allow to identify and quantify them. In this work, the TCC was efficiently degraded by UVC direct photolysis and the ecotoxicity of the UV-treated mixtures was investigated. Bioassays indicates that Daphnia similis (48 h EC50 = 0.044 μM) was more sensitive to TCC than Pseudokirchneriella subcapitata (72 h IC50 = 1.01 μM). TCC and its photoproducts caused significant effects on Eisenia andrei biochemical responses (catalase and glutathione-S-transferase); 48 h was a critical exposure time, since GST reached the highest activity values. UVC reduced the TCC toxic effect after 120 min. Furthermore, TCC was photodegraded in domestic wastewater which was simultaneously disinfected for total coliform bacterial (TCB) (360 min) and Escherichia coli (60 min).
Graphical abstract TCC degradation and ecotoxicological assessment
  相似文献   
697.
In the last two decades, there has been a rich debate about the environmental degradation that results from exposure to solid urban waste. Growing public concern with environmental issues has led to the implementation of various strategic plans for waste management in several developed countries, especially in the European Union. In this paper, the relationships were assessed between economic growth, renewable energy extraction and greenhouse gas (GHG) emissions in the waste sector. The Environmental Kuznets Curve hypothesis was analysed for the member states of the European Union, in the presence of electricity generation, landfill and GHG emissions for the period 1995 to 2012. The results revealed that there is no inverted-U-shaped relationship between income and GHG emissions in European Union countries. The renewable fuel extracted from waste contributes to a reduction in GHG, and although the electricity produced also increases emissions somewhat, they would be far greater if the waste-based generation of renewable energy did not take place. The waste sector needs to strengthen its political, economic, institutional and social communication instruments to meet its aims for mitigating the levels of pollutants generated by European economies. To achieve the objectives of the Horizon 2020 programme, currently in force in the countries of the European Union, it will be necessary to increase the share of renewable energy in the energy mix.  相似文献   
698.
The microclimatic monitoring of the historic church of Mogi?a Abbey (Kraków, Poland) was carried out to study the impact of the environmental parameters on the organic and hygroscopic artworks. Specific indexes were proposed to objectively assess the quality of time series of temperature (T), relative humidity (RH), and carbon dioxide (CO2) before applying the exploratory data analysis. The series were used to define the historic environmental conditions as stated in the European Standard EN 15757:2010 and with the use of the climate evaluation chart (CEC). It was found that the percentage of time in which T and RH values are within the allowable limits of the ASHRAE (2011) Class B is more than 85 %. This means that, for about 15 % of the time, there is a high risk of mechanical damage to highly vulnerable objects mainly due to the RH variability. The environment at the chancel resulted moister than that at the cornice, and the fungal growth is possible. In addition, the time-weighted preservation index (TWPI) is computed to evaluate the life expectancy of the objects, taking into account the environmental conditions of the site under study. The method of analogues, developed to predict the evolution of a system given observations of the past and without the knowledge of any equation among variables, was proposed and applied to the time series of temperature, relative humidity, and carbon dioxide with a 1-h sampling time to avoid the influence of the autocorrelation.  相似文献   
699.
Environmental Science and Pollution Research - Little is known about biosecurity measures and toxic effects during pesticide application in the province of Jujuy, Argentina, particularly concerning...  相似文献   
700.
Regional Environmental Change - This paper presents empirical data on household perceptions of capability to adapt to climate hazards and associated capacity needs. Households play an important...  相似文献   
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