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241.
Raymond Anthony 《Journal of Agricultural and Environmental Ethics》2012,25(6):813-841
Here, I investigate the challenges involved in addressing ethical questions related to food policy, food security, and climate change in a public engagement atmosphere where “experts” (e.g., scientists and scholars), policy-makers and laypersons interact. My focus is on the intersection between food and climate in the state of Alaska, located in the circumpolar north. The intersection of food security and climate represents a “wicked problem.” This wicked problem is plagued by “unruliness,” characterized by disruptive mechanisms that can impede how ethical issues in policy-making are broached. Unruliness is exacerbated by conditions of engagement that can be characterized as occurring in a “fog.” In this fog, interlocutors encounter both moral and epistemological conundrums. In considering how to mitigate unruliness, a bottom-up approach is recommended. I discuss “taming” strategies for addressing these ethical concerns; modest suggestions on what should be taken into count when confronting issues of science and ethics within the context of promoting greater deliberative discourse regarding food security issues at more local levels. My recommendations are made in light of developments in food policy in Alaska and may be instructive for other regions pursuing cold climate agricultural expansion, for example. 相似文献
242.
Li WW Sheng GP Zeng RJ Liu XW Yu HQ 《Environmental science and pollution research international》2012,19(5):1422-1431
Background and purpose
China's environmental problems and pollution control have global implications. China??s water pollution has been increasing with its urbanization and industrialization. Although great efforts have been taken to keep its wastewater discharge standards in pace with the water pollution development and technological advances, many challenges remain. A summary of the past achievements and lessons as well as the current problems in water pollution may provide a basis for future improvements in China and a reference for other countries.Methods
Statistical data are summarized to reveal the evolution of China??s population, wastewater discharge and corresponding discharge standards over the past four decades. In particular, the specific control indexes and number of controlled items are discussed in details. The present water pollution situation is clearly illustrated by the water pollution map and the water quality distribution diagram. A comparison between China??s present wastewater discharge standards and those in the USA and the EU are also presented to find the possibilities for future improvement.Results
The historical origins, major challenges and future perspectives of China??s wastewater discharge standards are overviewed. The barriers and ongoing efforts for standards formulation and implementation are highlighted. Some suggestions for future endeavors are given.Conclusions
China??s wastewater discharge standard system has seen significant improvement over the past decades, but it still has many defects and limitations. Nonetheless, unprecedented great efforts are underway to address all these challenges. More stringent standards and subsequently a cleaner water environment in China can be expected in the near future. 相似文献243.
Nitrate has become an increased regulatory concern due to gradual deterioration of surface and groundwater quality primarily related to widespread fertilizer use. Remediation of nitrate is a relatively straightforward process; however, nitrate impacts to groundwater are often a symptom of a sustained source from another nitrogen form (e.g., ammonia, ammonium nitrate, urea), analogous to how nonaqueous phase liquid can serve as a long‐term source of volatile organic compounds in groundwater. Understanding the various nitrogen transformation reactions when selecting, implementing, or documenting a remedy associated with nitrate is therefore critical to successfully reaching remedial endpoints. Case studies are presented that highlight in situ remedial successes with nitrogen‐impacted groundwater and discuss the key considerations that should be factored into remedy application. ©2015 Wiley Periodicals, Inc. 相似文献
244.
245.
F. Jason Martin Raymond C. Loehr 《Journal of the Air & Waste Management Association (1995)》2013,63(6):539-546
Abstract A biofilter does not operate as a true filter, but removes chemicals from gases by sorption and biologically degrades them. The objective of the research reported in this paper was to investigate the effect of periods of non-use on biofilter performance. The concept of non-use had two meanings in this research: "no chemical loading," which indicated that humidified air was passing through the biofilter with no chemicals, and "stagnant," which reflected that no flow at all was passing through the biofilter. Both instances of nonuse can require the microorganisms in the biofilter to reacclimate to differences in loading and type of chemical when a chemical load is re-applied. Acclimation time was compared with three different chemicals, initial acclimation was compared with re-acclimation following different periods of non-use, and the effect of humidification during the period of non-use was examined. Bench scale testing produced results indicating that acclimation times ranged from several hours to longer than a day. Longer periods of biofilter non-use resulted in longer reacclimation periods and transition between different chemicals resulted in acclimation periods shorter than initial acclimation periods. Stagnant periods produced longer re-acclimation periods than periods of no chemical loading. 相似文献
246.
Tony J. Ward Raymond F. Hamilton Jr. Garon C. Smith 《Journal of the Air & Waste Management Association (1995)》2013,63(7):1007-1013
Abstract The city of Missoula is located in a high mountain valley (elevation 3200 ft) in western Montana and contains one of the largest populations in the entire Rocky Mountain Region completely enclosed by mountains. During the 2000/2001 Missoula Valley Sampling Program, ambient levels of 61 semivolatile organic compounds (SVOCs) and 54 volatile organic compounds (VOCs) were originally quantified before refining the analytical program to 28 of the most prominent SVOCs and VOCs found in the Missoula Valley airshed. These compounds were measured over 24-hr periods at two locations throughout an entire year. This study provides the first, comprehensive appraisal of the levels of SVOCs and VOCs measured simultaneously throughout all four seasons at two locations in the Missoula Valley, including those levels measured during the 2000 Montana wildfire season. Generally, SVOC levels were comparable between both sides of the Missoula Valley. However, there were nearly double the amount of VOCs measured at the more urban Boyd Park site compared with the rural Frenchtown sampling site, a result of the greater number of automobiles on the eastern side of the Valley. SVOCs and VOCs were measured at their highest levels of the sampling program during the winter. Forest fire smoke samples collected during the summer of 2000 showed significant increases in SVOC phenolic compounds, including phenol, 2-methylphenol, 4-methylphenol, and 2,4-dimethylphenol. Although there were modest increases in some of the other SVOCs and VOCs measured during the fire season, none of the increases were as dramatic as the phenolics. 相似文献
247.
Greenhouse gas emissions from two soils receiving nitrogen fertilizer and swine manure slurry 总被引:2,自引:0,他引:2
Jarecki MK Parkin TB Chan AS Hatfield JL Jones R 《Journal of environmental quality》2008,37(4):1432-1438
The interactive effects of soil texture and type of N fertility (i.e., manure vs. commercial N fertilizer) on N(2)O and CH(4) emissions have not been well established. This study was conducted to assess the impact of soil type and N fertility on greenhouse gas fluxes (N(2)O, CH(4), and CO(2)) from the soil surface. The soils used were a sandy loam (789 g kg(-1) sand and 138 g kg(-1) clay) and a clay soil (216 g kg(-1) sand, and 415 g kg(-1) clay). Chamber experiments were conducted using plastic buckets as the experimental units. The treatments applied to each soil type were: (i) control (no added N), (ii) urea-ammonium nitrate (UAN), and (iii) liquid swine manure slurry. Greenhouse gas fluxes were measured over 8 weeks. Within the UAN and swine manure treatments both N(2)O and CH(4) emissions were greater in the sandy loam than in the clay soil. In the sandy loam soil N(2)O emissions were significantly different among all N treatments, but in the clay soil only the manure treatment had significantly higher N(2)O emissions. It is thought that the major differences between the two soils controlling both N(2)O and CH(4) emissions were cation exchange capacity (CEC) and percent water-filled pore space (%WFPS). We speculate that the higher CEC in the clay soil reduced N availability through increased adsorption of NH(4)(+) compared to the sandy loam soil. In addition the higher average %WFPS in the sandy loam may have favored higher denitrification and CH(4) production than in the clay soil. 相似文献
248.
Smith KE Putnam RA Phaneuf C Lanza GR Dhankher OP Clark JM 《Journal of environmental quality》2008,37(5):1855-1861
Runoff from turf environments, such as golf courses, is of increasing concern due to the associated chemical contamination of lakes, reservoirs, rivers, and ground water. Pesticide runoff due to fungicides, herbicides, and insecticides used to maintain golf courses in acceptable playing condition is a particular concern. One possible approach to mitigate such contamination is through the implementation of effective vegetative filter strips (VFS) on golf courses and other recreational turf environments. The objective of the current study was to screen ten aesthetically acceptable plant species for their ability to remove four commonly-used and degradable pesticides: chlorpyrifos (CP), chlorothalonil (CT), pendimethalin (PE), and propiconazole (PR) from soil in a greenhouse setting, thus providing invaluable information as to the species composition that would be most efficacious for use in VFS surrounding turf environments. Our results revealed that blue flag iris (Iris versicolor) (76% CP, 94% CT, 48% PE, and 33% PR were lost from soil after 3 mo of plant growth), eastern gama grass (Tripsacum dactyloides) (47% CP, 95% CT, 17% PE, and 22% PR were lost from soil after 3 mo of plant growth), and big blue stem (Andropogon gerardii) (52% CP, 91% CT, 19% PE, and 30% PR were lost from soil after 3 mo of plant growth) were excellent candidates for the optimization of VFS as buffer zones abutting turf environments. Blue flag iris was most effective at removing selected pesticides from soil and had the highest aesthetic value of the plants tested. 相似文献
249.
250.
Improved understanding of hyperaccumulation yields commercial phytoextraction and phytomining technologies 总被引:2,自引:0,他引:2
Chaney RL Angle JS Broadhurst CL Peters CA Tappero RV Sparks DL 《Journal of environmental quality》2007,36(5):1429-1443
This paper reviews progress in phytoextraction of soil elements and illustrates the key role of hyperaccumulator plant species in useful phytoextraction technologies. Much research has focused on elements which are not practically phytoextracted (Pb); on addition of chelating agents which cause unacceptable contaminant leaching and are cost prohibitive; and on plant species which offer no useful phytoextraction capability (e.g., Brassica juncea Czern). Nickel phytoextraction by Alyssum hyperaccumulator species, which have been developed into a commercial phytomining technology, is discussed in more detail. Nickel is ultimately accumulated in vacuoles of leaf epidermal cells which prevents metal toxicity and provides defense against some insect predators and plant diseases. Constitutive up-regulation of trans-membrane element transporters appears to be the key process that allows these plants to achieve hyperaccumulation. Cadmium phytoextraction is needed for rice soils contaminated by mine wastes and smelter emissions with 100-fold more soil Zn than Cd. Although many plant species can accumulate high levels of Cd in the absence of Zn, when Cd/Zn>100, only Thlaspi caerulescens from southern France has demonstrated the ability to phytoextract useful amounts of Cd. Production of element-enriched biomass with value as ore or fertilizer or improved food (Se) or feed supplement may offset costs of phytoextraction crop production. Transgenic phytoextraction plants have been achieved for Hg, but not for other elements. Although several researchers have been attempting to clone all genes required for effective hyperaccumulation of several elements, success appears years away; such demonstrations will be needed to prove we have identified all necessary processes in hyperaccumulation. 相似文献