Fractionation of fulvic acids: characteristics and complexation with copper

Two fulvic acid samples isolated from Suwannee river (International Humic Substance Society) and Feeitsuey reservoir were subjected to gel filtration chromatography (GFC) for molecular size fractionation. The GFC-eluted samples were separated into three groups corresponding to the molecular weight ranges: < 220, 220-1000, and 1000-4000. Fluorescence quenching techniques were employed for determining the conditional stability coefficient and kinetic parameters of copper complexation with the three fractions of fulvic acids. Experimental conditions were pH 6, 5 x 10(-5)m total copper and 5 mg C litre(-1) of fulvic acids. The conditional stability coefficients of the fulvic acid fractions were in the order of 0.9-3.3 x 10(5)m(-1), and the forward and reverse rate constants were in the order of 6.9-12.4 x 10(3)m(-1) s(-1) and 3.5-8.0 x 10(-2) s(-1). Information could be useful in modelling copper transport in the hydrosphere.     

The differing capabilities to respond to the challenge of climate change across Annex Parties under the Kyoto Protocol

The Kyoto Protocol marks the beginning of a new global effort to combat climate change. By constructing GDP and CO₂ emissions as two counteracting performance criteria on a per capita basis, this paper aims to advance the understanding of performance variation among different Annex groups under pressure from climate change. This differs from the traditional application of evaluation and aims to identify inherent efficiency differences across systems rather than separately based on the potential inefficiency of individual countries. The ‘world frontier’ for Annex Parties consists of three layers: Annex II forms the first layer, EIT and Annex III form the second layer, and Annex IV forms the third layer. The inferior performance observed in other non-Annex II Parties (EIT, Annex III, and Annex IV Parties) or the existence of a multi-frontier structure is due to an inherent system affiliation rather than poor performance on the part of the individual country. Annex IV Parties can be particularly vulnerable to controls on an emission intensity basis. By not only serving as a reference for future allocation schemes, the results can shed light on the function of a flexible reduction mechanism for countries that cooperate based on their common but differentiated responsibilities.     

Environmental Impact Assessment Regulation in Hong Kong and Shanghai: A Cross-city Analysis

Cross-city analysis in environmental regulation within non-democratic political systems is a neglected area. Taking policy convergence and styles of regulation as the focus, this paper has taken an initial step to compare the environmental impact assessment (EIA) regulation in Hong Kong and Shanghai. In this comparative exercise, it is identified that policy convergence occurs more explicitly in policy ideology and policy consequences, whereas divergence takes place in policy content, regulatory process and public consultation. Convergence, however, is only superficial whereas divergence is substantial. Indeed EIA systems of these two jurisdictions have displayed contrasting styles of regulation. The formal EIA system in Shanghai is dominated by the environmental agency, which regulates informal politics in the EIA process within a legal format. The informal EIA system in Hong Kong is co-ordinated by the environmental agency, which seeks active co-operation with the clients in a consultative EIA process in an informal and discretionary manner. What makes the Hong Kong system superior to the Shanghai system is the existence of institutional channels for public consultation. Within a non-democratic political setting, the EIA process in Hong Kong is more transparent and the EIA system is more accountable to the public, whereas the EIA process in Shanghai is lacking in transparency and the EIA system is under tight bureaucratic control.     

性能化火灾安全评估应用个案研究

性能化火灾安全评估屉当前火灾科学及其应用研究的热点之一。该方法利用火灾动力学、热化学、安全评估原理学等确定性工程方法，针对各类建筑的结构特点和实际状况，对建筑物的火灾危险进行定性的预测和评估。以某高层建筑的维修工程为例，评估了其维修期间的火灾安全水平。通过对其维修前（满足规范要求）和维修期间（不满足规范要求）两种情况下人员疏散过程的比较，并辅以烟气运动规律的预测，得出了该建筑在施工期间的安全水平。     

Decomposition of perfluorooctanoic acid by microwaveactivated persulfate: Effects of temperature, pH, and chloride ions

Microwave-hydrothermal treatment of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water with persulfate (S₂O ₈ ^2? ) has been found effective. However, applications of this process to effectively remediate PFOA pollution require a better understanding on free-radical scavenging reactions that also take place. The objectives of this study were to investigate the effects of pH (pH = 2.5, 6.6, 8.8, and 10.5), chloride concentrations (0.01?C0.15 mol·L^?1), and temperature (60°C, 90°C, and 130°C) on persulfate oxidation of PFOA under microwave irradiation. Maximum PFOA degradation occurred at pH 2.5, while little or no degradation at pH 10.5. Lowering system pH resulted in an increase in PFOA degradation rate. Both high pH and chloride concentrations would result in more scavenging of sulfate free radicals and slow down PFOA degradation. When chloride concentrations were less than 0.04 mol·L^?1 at 90°C and 0.06 mol·L^?1 at 60°C, presence of chloride ions had insignificant impacts on PFOA degradation. However, beyond these concentration levels, PFOA degradation rates reduced significantly with an increase in chloride concentrations, especially under the higher temperature.     

Concentrations and analysis of health risks of ambient air metallic elements at Longjing site in central Taiwan

Environmental Geochemistry and Health - The concentrations of particulates and metallic elements that were bound to total suspended particulates in ambient air at Long Cyuan Elementary School...     

Molecular sieve material from liquid–crystal-display waste glass and silicon carbide sludge via hydrothermal process with alkali fusion pretreatment

Journal of Material Cycles and Waste Management - The goal of this paper was to synthesize eco-humidity-conditioned Al-MCM-41 mesoporous molecular sieves (CHCMs) from liquid–crystal-display...     

Habitat segregation mediates predation by the benthic fish <Emphasis Type="Italic">Cottus gobio</Emphasis> on the exotic amphipod species <Emphasis Type="Italic">Gammarus roeseli</Emphasis>

Predation is often considered as one of the most important biotic factor determining the success of exotic species. The freshwater amphipod Gammarus roeseli has widely colonized Western Europe, where it is frequently found in sympatry with the native species (Gammarus pulex). Previous laboratory experiments revealed that G. roeseli may have an advantage over G. pulex through differential predation by native fish (brown trout). Morphological anti-predator defences (spines) were found responsible for lower rates of predation on the invasive G. roeseli. Here, using both field surveys and laboratory experiments, we tested if a differential of predation exists with other fish predators naturally encountered by gammarids. The main predators present in our field site were nocturnal benthic feeders (mainly bullheads, Cottus gobio). Fish diet analysis showed that, compared to its global availability in the river, G. roeseli was less consumed than G. pulex. In the field, however, G. roeseli was found mainly in the aquatic vegetation whereas G. pulex was found in all habitat types. Laboratory experiments in microcosms revealed that G. roeseli was less prone to predation by C. gobio only when vegetation was present. Depending on the type of predator, the differential of predation could therefore be mediated by antipredator behaviour, and a better usage of refuges, rather than by morphological defences.     

Atmospheric-particulates-bound mercury Hg(p) study at five characteristic sampling sites in Taiwan

The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009-2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).     

Effect of composting on characterization and leaching of copper, manganese, and zinc from swine manure.

This research was conducted to study the influence of composting on the concentrations, water solubility, and phase association of Cu, Mn, and Zn from swine (Sus domesticus) feces. Composting of separated swine manure was performed in two piles for 122 days. The metal concentrations increased rapidly during the first 49 days and leveled off thereafter. All metal concentrations increased approximately 2.7-fold in the final compost due to decomposition of organic matter. A sequential extraction protocol was used to evaluate the humification process and partition metals into water-soluble, exchangeable, organically complexed, organically bound, solid particulate, and residual fractions. Temporal changes in the water-soluble fractions of Cu, Mn, and Zn were reflected by water-soluble organic C concentrations, which rapidly increased to a maximum at Day 18 and declined thereafter. An increase in the humic acid/fulvic acid ratio in Na4P2O7 or NaOH extracts at various stages of composting represented the humification process. During composting, the major portions of Cu, Mn, and Zn were in the organically-bound, solid particulate, and organically complexed fractions, respectively. Metal distributions in different chemical fractions were generally independent of composting age and, thus, independent of respective total metal concentrations in the composts.