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891.
Sebastian Strunz Bernd Klauer Irene Ring Johannes Schiller 《Sustainability Science》2017,12(3):421-432
The flaws of mainstream economic methodology are becoming widely acknowledged. Should we, therefore, reject all of its concepts within the quest for sustainability? A predicament looms: neither would it make sense to neglect useful tools, nor to redundantly replicate the mainstream’s narrow perspective on sustainability problems. We argue that avoiding both fallacies is possible because power of judgment facilitates non-dogmatic methodological decisions: the scientists’ judgment, that is, the capacity to apply general concepts to specific situations, supports their decisions concerning which methods are suitable for tackling a given sustainability problem. The intersubjective quality of judgment prevents the resulting methodological pluralism from drifting toward arbitrariness. 相似文献
892.
893.
Cram S Ponce De León CA Fernández P Sommer I Rivas H Morales LM 《Environmental monitoring and assessment》2006,121(1-3):127-149
Possible contaminants produced by the Petroleos Mexicanos (PEMEX) marine oil complex in the vicinity of the Cayo Arcas (Mexico) coral reef ecosystem were evaluated by analyzing sediments and sea water for hydrocarbons and metal elements. We found that the concentrations of aliphatic hydrocarbons in the sea water were generally low, with the highest values detected near the oil station; the concentration of polycyclic aromatic hydrocarbons (PAHs) was generally below the detection limit. The hydrocarbons found in the sediments seem to have a pyrogenic origin, and were probably produced by marine traffic in the study area. The total PAH concentration did not exceed the NOAA criteria, although levels of some individual PAHs did. The only metal detected in the sea water at high concentrations was nickel. The Ni/V ratio in the sediments indicates the contribution of crude oil to the system. The high content of Ni and Zn was attributed to the ballast waters from the oil tankers that load at the station's monobuoys. The presence of fine sediments that commonly originate from terrestrial ecosystems supported this assumption. 相似文献
894.
Cram S Sommer I Morales LM Oropeza O Carmona E González-Medrano F 《Journal of environmental management》2006,80(1):13-24
A land suitability study was carried out by applying a multiple-criteria technique to 12 different vegetation types in Mexico's Tamaulipas state to help select potentially suitable sites for hazardous waste treatment plants. Species richness, spatial distribution, and uniqueness were selected as the criteria for estimating a vegetation type's suitability. Using the analytical hierarchy process, we ranked and mapped vegetation types, then compared the results with rankings of the same vegetation types based only on their number of endemic species. The suitabilities of the various vegetation types were ordered in more or less the same way by both methods, except in two cases for which the results were very different. The method proved to be a useful tool despite the availability of only partial (mostly qualitative) information; under such circumstances, expert experience can be incorporated in the evaluation process to a limited degree. The technique described in this paper has a high potential to aid decisions when many opinions and options must be considered simultaneously. 相似文献
895.
896.
湖南蔡家塘森林小流域氮和硫的输入输出特征 总被引:5,自引:3,他引:2
以湖南韶山蔡家塘小流域2001~2003年的监测数据为基础,对森林在酸沉降作用下无机氮(NH 4,NO-3)和硫输入、输出的月均通量进行了研究.结果表明,总氮的年输入通量为24~28 kg·hm-2·a-1,主要以NH 4形式(占总输入氮的62%~67%)输入该森林生态系统;年氮输出通量为2~3kg·hm-2·a-1,主要以NO-3形式(占总输出N的83%~98%)输出该森林生态系统.韶山森林年无机氮的滞留量达到22~26kg·hm-2·a-1,其中NH 4占到总氮净截留量的68%~72%.硫的截留量为13~21 kg·hm-2·a-1.高氮沉降导致了一部分氮的输出,但是输出氮仅占到输入氮的8%~9%.有超过90%的氮被生态系统截留.由此可以推断,韶山森林尽管有高氮输入,但是生态系统远没有达到氮饱和状态. 相似文献
897.
利用批量试验研究了不同浓度的亚硝酸盐对聚磷菌好氧摄磷过程的影响,以及在含盐废水硝化过程中亚硝酸盐的累积对聚磷菌好氧摄磷的影响.试验结果表明:亚硝态氮浓度为4 mg/L时,对聚磷菌摄磷有抑制作用,其对摄磷速率的抑制系数为0.08;亚硝态氮浓度为15 mg/L时,对聚磷菌摄磷产生明显的抑制,抑制系数增加到0.61.亚硝酸盐对聚磷菌的抑制作用主要与亚硝酸有关.本研究中亚硝酸浓度在0.000 2 mg/L以上时即对聚磷菌产生较强的抑制作用.亚硝酸盐对聚磷菌的抑制作用只是在亚硝酸盐存在的条件下才发生,一旦亚硝酸盐消失,对聚磷菌的抑制作用即可解除.含盐废水硝化过程中,在好氧反应开始1~2 h内,由于亚硝态氮浓度低,其对聚磷菌摄磷抑制作用小.随着亚硝态氮的逐步累积,亚硝态氮浓度达到8~9mg/L以上时,其对聚磷菌摄磷的抑制作用逐渐增强.进水氨氮浓度高时,好氧反应过程中pH值较低,会导致亚硝酸浓度增高,致使磷酸根的吸收量减少. 相似文献
898.
899.
900.
Fluorescence spectroscopic characterization of dissolved organic matter fractions in soils in soil aquifer treatment 总被引:2,自引:0,他引:2
Shuang Xue Qingliang Zhao Liangliang Wei Youtao Song Mei Tie 《Environmental monitoring and assessment》2013,185(6):4591-4603
This work investigated the effect of soil aquifer treatment (SAT) operation on the fluorescence characteristics of dissolved organic matter (DOM) fractions in soils through laboratory-scale soil columns with a 2-year operation. The resin adsorption technique (with XAD-8 and XAD-4 resins) was employed to characterize the dissolved organic matter in soils into five fractions, i.e., hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N), and hydrophilic fraction (HPI). The synchronous fluorescence spectra revealed the presence of soluble microbial byproduct- and humic acid-like components and polycyclic aromatic compounds in DOM in soils, and SAT operation resulted in the enrichment of these fluorescent materials in all DOM fractions in the surface soil (0–12.5 cm). More importantly, the quantitative method of fluorescence regional integration was used in the analysis of excitation–emission matrix (EEM) spectra of DOM fractions in soils. The cumulative EEM volume (Φ T, n ) results showed that SAT operation led to the enrichment of more fluorescent components in HPO-A and TPI-A, as well as the dominance of less fluorescent components in HPO-N, TPI-N, and HPI in the bottom soil (75–150 cm). Total Φ T, n values, which were calculated as $ {\Phi_{{T,n}}} \times {\mathrm{DOC}} $ , suggested an accumulation of fluorescent organic matter in the upper 75 cm of soil as a consequence of SAT operation. The distribution of volumetric fluorescence among five regions (i.e., P i, n ) results revealed that SAT caused the increased content of humic-like fluorophores as well as the decreased content of protein-like fluorophores in both HPO-A and TPI-A in soils. 相似文献