Advanced Materials Research Vols. 518-523

Abstract: Abstract: This article describes the distribution characteristics of soil microbial in different vegetable types in artificial wetland restoration. The results show that quantity of microbial had a significant increase before and after restoration. The value of Polygonum hydropiper sample was largest. The sequence of increase was Polygonum hydropiper,Phragmites communis Trin,Typha angustifolia and bare land; Referring to the change of three types of microorganisms, bacteria enhance 2.16 times largest; Meanwhile fungi go up 1.11 times least. The range of microbial diversity value before restoration is 0.2437-0.7633, and after is 0.1163-0.4069;Bacteria amount had significant correlation with TN.

Abstract: The photosynthetic efficiency of Tamarix ramosissima Ledeb., one of the major natural plants in the southern oasis-desert ecotone of the Taklimakan Desert, was investigated to assess the ecological effects of duststorms on T ramosissima Ledeb. We measured daily chlorophyll a (Chl a) fluorescence parameters of mature leaves of healthy 10-years old T. ramosissima L. during months of July and August in 2008, using a portable modulated Chl a fluorometer PAM-2100 and three duststorm days were singled out to assess the affects of duststorms on the photosynthetic efficiency. Our results showed that duststorms increased the energy absorption and the increased absorption then enhanced the photosynthetic efficiency of T. ramosissima L. under duststorm weather conditions. Our results also showed that the qP (quenching coefficients for photosynthesis) was significantly decreased and qN (quenching coefficients for non-photosynthesis) was significantly increased during the maximum period of solar readiation between 14:00 and 16:00 under normal conditions, implying that stress might occur in normal weather conditions, but lowered stress to T ramosissima Ledeb. during duststorm weather conditions. In a word, duststorm-facilitated might provide favorable opportunities for constructing and expansing oasis-desert ecotone.

Abstract: Effect of EDTA and EDDS on phytoremediation of Pb- and Zn- contaminated soil by Brassica Juncea was investigated in this work. Especially, the effect of the kind and the method of adding chelating agent was investigated during the plant growth. Plants were grown in an environmental control system. The biomass of the whole plant was weighed, and the uptake of Pb and Zn in shoot and root were determined using ICP-AES. Consequently, the following matters have been obtained: (1) Both EDTA and EDDS significantly enhanced the translocation of metals (Pb and Zn) in soil from root to shoot. Furthermore, the two chelating agents resulted in a sharply biomass loss for more than 30% of the control. As a result, the total uptake amount of metals by Brassica Juncea was decreased (except the uptake of Pb with the addition of 3.0 mmol•kg-1 EDTA). (2) EDDS showed the higher inhibition for the growth of Brassica Juncea than EDTA. (3) The method for adding EDTA and EDDS at several times separately did not necessarily increase the uptake of heavy metals.

Abstract: Studies on the responses of fish to suspended solids (SS) have focused on freshwater salmonid species, far less is about marine species. In this study, juveniles of black sea bream Acanthopagrus schlegelii were exposed continuously to various concentrations of uncontaminated SS for 10 days to detect gill damage, and then returned to clean seawater without SS for 10 days to detect gill recovery. The results showed that, no clear changes in chloride cells, Na+-K+-ATPase activity and DNA damage parameters (comet cell rate, tail length and tail moment) were observed after 10 days of exposure to 100 mg SS/L, while at 1000 mg SS/L these paramaters were significantly altered. After the 1000 mg/L SS-treated fish were transferred from water containing SS to clean seawater only, Na+-K+-ATPase activity, tail length and tail moment all indicated signs of recovery, but these kinds of recoveries were incomplete and did not return to the control levels. The rapid response and recovery observed in our study show that high concentration uncontaminated SS can induce gill damage of juveniles of A. schlegelii, and this kind of damage is difficult to recover completely.

Abstract: Wetland is the important part in urban ecosystem. Microorganisms is integral component of urban wetland ecosystem is the main factor of wetlands sewage treatment, and plays an irreplaceable role in the degradation. In this paper, the authors regard urban wetland of Harbin in north shore of Songhua river as the research object, through experiments to identify the microorganisms types, finding five microorganisms types being nitrify fungi. The article analyzes the contributions of microorganisms in nitrogen cycle of urban wetland. It is present that microorganisms plays an irreplaceable role in controlling pollutions and nitrification and anti-nitrification reactions play the most significant role in the degradation of nitrogen compounds and ammonium oxidation is a possible process in deducing nitrogen pollutions.

Abstract: This text researches some influences of the negative environment effect caused by many years mining development projects on TongGuan gold mine area water resources and eco-environment system. On this base, some measures to water resources and eco-environment protection are put forward, and these have important meaning to the restoration of mineral mountain environment.

Abstract: The high population density and numerous open-pit mines in Jinsha River basin interfere local landscape to a large extent. The present paper discusses the relation between landscape characteristics and population density & area of open-pit mines, by dividing the basin into three sections (i.e. upstream, midstream and downstream) and conducting comparative analysis of the spatial relation between landscape characteristics and population density & area of open-pit mines. Study conclusions: ①major vegetation within the basin includes forestry, shrub grassland and xerophytic cultivated plants and the three sections significantly differ from each other: forestry is densely distributed in upper section, shrub in middle section and xerophytic cultivated plants in lower section; ②the spatial distribution rule of landscape fragmentation level is: middle section > lower section > upper section; ③ the spatial distribution landscape fragmentation level is in proportion to population density & area of open-pit mines: middle section has the highest population density and the largest number of open-pit mines, where the landscape is most seriously divided and patches are the most complicated; ④based on the previous conclusions, proposals for management, protection and control in different sections are provided: middle section – key zone of ecological environment management, upper section – key zone of ecological environment protection, lower section – key zone of ecological environment restoration and control. The study results can serve as ponderable reference for ecological protection and restoration in the basin.

Abstract: The climate change issue and the real or potential substantial climate migration arising from climate change and its adverse impacts have become a severe challenge for human society in the 21st century, and one of the core concerns of human society today. Through the analysis of the climate migration mechanism during the course of social development, and the conceptual definition of climate migrants, this paper aims to strengthen our understanding and perception of climate migration, and further grasp the essence and law of evolution of climate migration, so as to make a preliminary exploration into how to tackle the challenge of climate migration arising from climate change, mitigate social risks facing climate migration, and promote the benign operation and balanced development of society effectively.

Abstract: Nitrous oxide (N₂O) is the fourth most prevalent greenhouse gas in the atmosphere after carbon dioxide (CO₂), methane (CH₄), and water vapor. This gas contributes most significantly to global warming since it decomposes with great difficulty in the atmosphere, even in low concentrations. Emissions of N₂O gas are known to have an impact 310 times greater than the impact of CO₂ on global warming. According to the Intergovernmental Panel on Climate Change, N₂O concentration in the atmosphere has increased by 46 ppb (17%) since 1750, and continues to increase. A biofilter works by draining the contaminated air flow through a porous medium in which contaminants in the air flow are adsorbed by biofilms; these contaminants are then oxidized to produce biomass, CO₂, H₂O, nitrate (NO₃^-), and sulfate (SO₄^2-). In addition, the biofilter supports the growth of microorganisms present in the porous medium. This research was conducted to investigate the performance of two types of a compost-based filter medium in 9 hours N₂O biofiltration, with N₂O flow rate variations and variations in water content levels of the filter medium. A biofiltration experiment was conducted to evaluate the effects of selected parameters on N₂O removal efficiency. The results showed that goat manure-based compost was more effective in reducing N₂O compared with cow manure-based compost, with the highest efficiency of 70.1%.

Abstract: Ecological safety problem from mining activities can not be ignored. Mining ecological security not only relates to ecological environment, also involves technology environment, political environment and cultural environment, etc. Through comprehensive analysis of situation and problems of mining ecological security, we can find Hengyang must go green mining road and must construct ecological mining from the environmental ecology, the political ecology and the cultural ecology, in order to realize mining sustainable development.