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51.
The study examines the history of strategic decision-making concerning water protection in Helsinki, 1850-2000. We identified five major strategic decisions that occurred during the study period. The results indicate that strategic decision-making evolves in long-term policy cycles that last on average 20-30 years. New policy cycles are caused by paradigm shifts. Paradigms are shared and predominant ways of understanding reality that help when groups must act to solve common and complex environmental problems. However the internal structure and external dynamics of paradigms are contradictory. Although paradigms serve initially as means to redefine problems and find creative solutions, as time goes by each paradigm seems to become also a barrier that restricts the introduction of new ways of thinking and acting. The power of paradigms lies in the fact that they can be defined as scientific but also social, political, or cultural agreements depending on the context. 相似文献
52.
Miguel A. Sánchez-Monedero Edward I. Stentiford Sari T. Urpilainen 《Journal of the Air & Waste Management Association (1995)》2013,63(5):612-618
Abstract Bioaerosol release from composting plants is a cause of concern because of the potential health impacts on site workers and local residents. A one-year monitoring was undertaken in a typical composting plant treating green wastes by windrowing in the open. Aspergillus fumigatus spores and mesophilic bacteria were used as monitoring parameters and were collected in a six-stage Andersen sampler impactor from the air at different locations and during different operational activities. Background concentrations of both microorganisms were generally below 1000 colony-forming units m?3 when no vigorous activity was taking place. Shredding of fresh green wastes, pile turning, and screening of mature compost were identified as the activities generating the highest amounts of both bioaerosols 40 m downwind of the composting pad. These air concentrations were ~2 log units higher than background levels. Screening of mature compost generated lower amounts of A. fumigatus than the other two activities (an average of 1 log unit higher than background levels). Workers were identified as the main potential receptors of high bioaerosol concentrations in areas close to the composting pad, whereas no major risk for local residents was expected because the concentrations recorded at distances of 200 and 300 m downwind of the operational area were not significantly different from background levels. 相似文献
53.
Sari Vilhunen Heikki Särkkä Mika Sillanpää 《Environmental science and pollution research international》2009,16(4):439-442
Background, aim, and scope The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps,
like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient
and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of
two emitted wavelengths and different test mediums to Escherichia coli destruction.
Materials and methods Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors
both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and
water with humic acids.
Results Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared
to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also,
the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial
reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases.
Discussion When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra
substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower
wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was
small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage.
Conclusions UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but
the test medium did not have much impact.
Recommendations and perspectives This study found UV LEDs to be an optimal method for bacterial disinfection. The emitted wavelength was found to be an essential
factor when using LEDs; thus, care should be taken in selecting the proper LED for maximum disinfection. 相似文献
54.
Scenarios for shipping traffic in the Gulf of Bothnia (GoB) by 2030 are described in order to identify the main factors that should be taken into account when preparing a Maritime Spatial Plan (MSP) for the area. The application of future research methodology to planning of marine areas was also assessed. The methods include applying existing large scale quantitative scenarios for maritime traffic in the GoB and using real-time Delphi in which an expert group discussed different factors contributing to future maritime traffic in the GoB to find out the probability and significance of the factors having an impact on maritime traffic. MSP was tested on transnational scale in the Bothnian Sea area as a pilot project. 相似文献
55.
Mazaher Moeinaddini Abbas Esmaili Sari Alireza Riyahi bakhtiari Andrew Yiu-Chung Chan Seyed Mohammad Taghavi Darryl Hawker Des Connell 《Environmental science and pollution research international》2014,21(12):7757-7772
The vertical concentration profiles and source contributions of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in respirable particle samples (PM4) collected at 10, 100, 200 and 300-m altitude from the Milad Tower of Tehran, Iran during fall and winter were investigated. The average concentrations of total PAHs and total n-alkanes were 16.7 and 591 ng/m3, respectively. The positive matrix factorization (PMF) model was applied to the chemical composition and wind data to apportion the contributing sources. The five PAH source factors identified were: ‘diesel’ (56.3 % of total PAHs on average), ‘gasoline’ (15.5 %), ‘wood combustion, and incineration’ (13 %), ‘industry’ (9.2 %), and ‘road soil particle’ (6.0 %). The four n-alkane source factors identified were: ‘petrogenic’ (65 % of total n-alkanes on average), ‘mixture of petrogenic and biomass burning’ (15 %), ‘mixture of biogenic and fossil fuel’ (11.5 %), and ‘biogenic’ (8.5 %). Source contributions by wind sector were also estimated based on the wind sector factor loadings from PMF analysis. Directional dependence of sources was investigated using the conditional probability function (CPF) and directional relative strength (DRS) methods. The calm wind period was found to contribute to 4.4 % of total PAHs and 5.0 % of total n-alkanes on average. Highest average concentrations of PAHs and n-alkanes were found in the 10 and 100 m samples, reflecting the importance of contributions from local sources. Higher average concentrations in the 300 m samples compared to those in the 200 m samples may indicate contributions from long-range transport. The vertical profiles of source factors indicate the gasoline and road soil particle-associated PAHs, and the mixture from biogenic and fossil fuel source-associated n-alkanes were mostly from local emissions. The smaller average contribution of diesel-associated PAHs in the lower altitude samples also indicates that the restriction of diesel-fueled vehicle use in the central area of Tehran has been effective in reducing the PAHs concentration. 相似文献
56.
Ahmet Demirak Hanife Ayd?n Y?lmaz Feyyaz Keskin Yal??n ?ahin O?uz Akpolat 《Environmental monitoring and assessment》2012,184(12):7113-7124
The Bay of Gokova in Southeastern Aegean Sea (Turkey) is important by the potential of agricultural, municipal, and tourism activities. In addition, there is no industrial plant within the area in the Aegean Sea. Kad?n Creek (Azmak) and Ak?ap?nar Creek (Azmak) flowing into the inner Gokova Bay are one of the important factors in determining the character of the inner Gokova Bay. In this study, nine stations were selected in the inner Gokova Bay, Kad?n Creek, and Akcap?nar Creek. The concentrations of Cd, Cu, Fe, Pb, and Zn were measured in suspended particulate matter (SPM) and sediments. The samples of sediments and SPM were collected in between February 2008 and September 2008. The aim of the study is searching the change of concentrations of Cd, Cu, Fe, Pb, and Zn in suspended particulate matter and sediments in the inner Gokova bay, Kad?n Creek, and Ak?ap?nar Creek. It has been identified that the metal concentrations in the creeks are higher than the metal concentrations in the marine environment. It has also been observed that the concentrations of Pb, Cd, and Cu in summer season have been higher than in the winter season, but the concentrations of Fe and Zn have not shown a significant difference between in summer and winter seasons. The obtained results show that the some heavy metals are caused by the agricultural, municipal, and tourism activities operating in the coastal areas and terrestrial environment, and they are transported from the creeks to the Gokova Bay by suspended particulate matter. 相似文献
57.
Suni S Koskinen K Kauppi S Hannula E Ryynänen T Aalto A Jäänheimo J Ikävalko J Romantschuk M 《Ambio》2007,36(2-3):173-179
This study examined the efficiency of cotton grass fibers in removing diesel oil from the surface of water in conditions prevailing in the Baltic Sea. The effect of low temperature, salinity, and bacterial amendments were tested in laboratory-scale set-ups, whereas 600-L mesocosms filled with Baltic Sea water were used for testing the effects of diesel oil and rapid removal of the oil on microorganisms, phytoplankton, and mussels. Cotton grass proved to be an excellent sorbent for diesel oil from the water surface at a low temperature. Inoculation with diesel-enriched microorganisms enhanced degradation of oil significantly in laboratory-scale experiments. In mesocosm experiments, the addition of diesel oil (0.66 mg L(-1), 0.533 L m(-2)) to the basins resulted in higher microbial density than in all other basins, including inoculated ones, suggesting that the Baltic Sea contains indigenous hydrocarbon degraders. The removal of oil with cotton grass significantly improved the survival of mussels in the mesocosm tests: 100% mortality in diesel basins versus 0% mortality in basins with cotton grass, respectively. However, the surviving mussels suffered from histopathological changes such as inflammatory responses, degenerations, and cell death. The observed rescuing effect was observable even when the cotton grass-bound oil was left in the water. The results underline the importance of rapid action in limiting damage caused by oil spills. 相似文献
58.
Yucel Guney Yasin Dursun Sari Muhsin Yalcin Ahmet Tuncan Senayi Donmez 《Waste management (New York, N.Y.)》2010,30(8-9):1705-1713
In this study, the potential re-use of waste foundry sand in high-strength concrete production was investigated. The natural fine sand is replaced with waste foundry sand (0%, 5%, 10%, and 15%). The findings from a series of test program has shown reduction in compressive and tensile strengths, and the elasticity modulus which is directly related to waste foundry inclusion in concrete. Nevertheless the concrete with 10% waste foundry sand exhibits almost similar results to that of the control one. The slump and the workability of the fresh concrete decreases with the increase of the waste foundry sand ratio. Although the freezing and thawing significantly reduces the mechanical and physical properties of the concrete. The obtained results satisfies the acceptable limits set by the American Concrete Institute (ACI). 相似文献
59.
Miia Vilve Sari Vilhunen Mikko Vepsäläinen Tonni Agustiono Kurniawan Niina Lehtonen Hannu Isomäki Mika Sillanpää 《Environmental science and pollution research international》2010,17(4):875-884
Background, aim, and scope
Chlorinated volatile organic compounds (CVOCs), widely used in industry as solvents and chemical intermediates in the production of synthetic resins, plastics, and pharmaceuticals, are highly toxic to the environment and public health. Various studies reported that Fenton’s oxidation could degrade a variety of chlorinated VOCs in aqueous solutions. In acidic conditions, ferrous ion catalyzes the decomposition of H2O2 to form a powerful •OH radical. In this study, wastewater from wash of ion-exchange resin containing typical CVOC, 1,2-dichloroethane, was treated using Fenton’s oxidation. To reduce environmental load and processing costs of wastewater, Fenton process as a simple and efficient treatment method was applied to degrade 1,2-dichloroethane of wash water. 相似文献60.
Sánchez-Monedero MA Stentiford EI Urpilainen ST 《Journal of the Air & Waste Management Association (1995)》2005,55(5):612-618
Bioaerosol release from composting plants is a cause of concern because of the potential health impacts on site workers and local residents. A one-year monitoring was undertaken in a typical composting plant treating green wastes by windrowing in the open. Aspergillus fumigatus spores and mesophilic bacteria were used as monitoring parameters and were collected in a six-stage Andersen sampler impactor from the air at different locations and during different operational activities. Background concentrations of both microorganisms were generally below 1000 colony-forming units m(-3) when no vigorous activity was taking place. Shredding of fresh green wastes, pile turning, and screening of mature compost were identified as the activities generating the highest amounts of both bioaerosols 40 m downwind of the composting pad. These air concentrations were approximately 2 log units higher than background levels. Screening of mature compost generated lower amounts of A. fumigatus than the other two activities (an average of 1 log unit higher than background levels). Workers were identified as the main potential receptors of high bioaerosol concentrations in areas close to the composting pad, whereas no major risk for local residents was expected because the concentrations recorded at distances of 200 and 300 m downwind of the operational area were not significantly different from background levels. 相似文献