Fe2O3控制再燃脱硝中间产物HCN

再燃脱硝过程的中间产物HCN在燃尽过程的二次氧化对最终NO的脱除效率影响很大,有效控制HCN的转化对提高再燃脱硝的效率具有重要意义.以天然气和150目废轮胎粉为再燃燃料,利用模拟烟气在陶瓷管反应器中对典型条件下的再燃脱硝特性和中间产物HCN/NH3的生成特性进行了实验研究.结果表明在典型的再燃条件下,随着再燃区空气系数...     

Interseasonal hydrological characteristics and variabilities in surface water of tropical estuarine ecosystems within Niger Delta, Nigeria

We present a seasonal and baseline survey of selected physicochemical parameters in epipelagic samples from Qua Iboe (QIB) and Cross River (CRV) estuaries in Niger Delta region of Nigeria. The parameters analysed were temperature, pH, salinity, turbidity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total organic carbon (TOC), total nitrogen, available phosphorus, Ca^2?+?, Mg^2?+?, Na^?+?, K^?+? (exchangeable cations) and ${\rm SO}_{4}^{2-}$ , Cl^???, ${\rm NH}_{4}^{+}$ and ${\rm NO}_{3}^{-}$ . The results showed that the physicochemical parameters exhibited spatiotemporally explicit variabilities. The mean levels of the parameters were higher during the wet season (June–September) except salinity, DO, Cl^??? and ${\rm NH}_{4}^{+}$ in CRV, whilst QIB recorded higher mean levels for temperature, pH, salinity, BOD, TOC, ${\rm SO}_{4}^{2-}$ , Cl^??? and ${\rm NH}_{4}^{+}$ during the dry season (November–February). Significant seasonal variability was recorded for salinity, DO, turbidity, TSS, ${\rm SO}_{4}^{2-}$ and ${\rm NH}_{4}^{+}$ levels in CRV and for turbidity, DO, BOD, TSS, TOC, available P, Na, Cl^??? and ${\rm NO}_{3}^{-}$ levels in QIB. This study confirmed that the degree of variability of the various physicochemical surface water quality indicators is dependent on the prevalent environmental estuarine factors.     

South Korean managerial reactions to voicing discontent: The effects of employee attitude and employee communication styles

Using a scenario‐based experiment, this study examined how employee attitude and employee communication styles affected managers' reactions to employees' objections to a company policy. In the experiment, employee attitude (cynical versus trusting) and employee communication styles (aggressive versus diplomatic) were manipulated, and managers' reactions to voicing discontent were assessed through a questionnaire. Based on a sample of 185 middle managers working in various organizations in South Korea, the results showed that managers were more likely to engage in social undermining and were less likely to provide social support when cynical (rather than trusting) employees objected to a company policy. Also, attributed motives (i.e., personal attack and health concern) fully mediated the relationship between employee attitude and social support and social undermining. In addition, managers more likely attributed the objection to moral concerns when trusting (rather than cynical) employees communicated in an aggressive manner. Copyright © 2009 John Wiley & Sons, Ltd.     

II. Incidence of Acute Respiratory Illness

A study of acute respiratory illness was conducted from November 1968 through April 1969 among families residing in an area of relatively high nitrogen dioxide exposure, in an area of elevated suspended particulate exposure, and in two control areas of Greater Chattanooga. Respiratory illness rates were consistently higher in all family segments in the high-nitrogen dioxide exposure area when rates were averaged for the entire 24 weeks of study, the A₂/Hong-Kong epidemic period, or post-epidemic interval. A relative excess in respiratory illness of 18.8 percent was found among families exposed to elevated NO₂ concentrations and an excess of 10.4 percent was found among families in the elevated-suspended particulate exposure area.     

Life cycle based risk assessment of recycled materials in roadway construction

This paper uses a life-cycle assessment (LCA) framework to characterize comparative environmental impacts from the use of virgin aggregate and recycled materials in roadway construction. To evaluate site-specific human toxicity potential (HTP) in a more robust manner, metals release data from a demonstration site were combined with an unsaturated contaminant transport model to predict long-term impacts to groundwater. The LCA determined that there were reduced energy and water consumption, air emissions, Pb, Hg and hazardous waste generation and non-cancer HTP when bottom ash was used in lieu of virgin crushed rock. Conversely, using bottom ash instead of virgin crushed rock increased the cancer HTP risk due to potential leachate generation by the bottom ash. At this scale of analysis, the trade-offs are clearly between the cancer HTP (higher for bottom ash) and all of the other impacts listed above (lower for bottom ash). The site-specific analysis predicted that the contaminants (Cd, Cr, Se and Ag for this study) transported from the bottom ash to the groundwater resulted in very low unsaturated zone contaminant concentrations over a 200 year period due to retardation in the vadose zone. The level of contaminants predicted to reach the groundwater after 200 years was significantly less than groundwater maximum contaminant levels (MCL) set by the US Environmental Protection Agency for drinking water. Results of the site-specific contaminant release estimates vary depending on numerous site and material specific factors. However, the combination of the LCA and the site specific analysis can provide an appropriate context for decision making. Trade-offs are inherent in making decisions about recycled versus virgin material use, and regulatory frameworks should recognize and explicitly acknowledge these trade-offs in decision processes.     

The Scaling of Water Governance Tasks: A Comparative Federal Analysis of the European Union and Australia

Conflicts over how to “scale” policy-making tasks have characterized environmental governance since time immemorial. They are particularly evident in the area of water policy and raise important questions over the democratic legitimacy, economic efficiency and effectiveness of allocating (or “scaling”) tasks to some administrative levels as opposed to others. This article adopts a comparative federalism perspective to assess the “optimality” of scaling—either upward or downward—in one issue area, namely coastal recreational water quality. It does so by comparing the scaling of recreational water quality tasks in the European Union (EU) and Australia. It reveals that the two systems have adopted rather different approaches to scaling and that this difference can partly be accounted for in federal theoretical terms. However, a much greater awareness of the inescapably political nature of scaling processes is nonetheless required. Finally, some words of caution are offered with regard to transferring policy lessons between these two jurisdictions.     

Petroleum hydrocarbons and limiting nutrients in <Emphasis Type="Italic">Macura reptantia</Emphasis>, <Emphasis Type="Italic">Procambarus clarkii</Emphasis> and benthic sediment from Qua Iboe Estuary,Nigeria

The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector. Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February 2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting the potential for exposure of the resident biota and the risk to human health.     

3D MRI measurements of the effects of wind direction on flow characteristics and contaminant dispersion in a model urban canopy

Environmental Fluid Mechanics - Three dimensional velocity fields and contaminant dispersion within an evenly spaced orthogonal array of cubic buildings (height = H) with a central tall...     

Crop uptake of heavy metals in response to the environment and agronomic practices on land near mine tailings in the Zambian Copperbelt Province

Environmental Geochemistry and Health - A field experiment was undertaken on farmers’ fields adjacent to a large mine tailings dam in the Zambian mining town of Kitwe. Experimental plots were...