Environmental Science and Pollution Research - Simulating changes in the value of ecosystem services caused by land use changes in large cities under multiple scenarios is of great significance for... 相似文献
The optical beam deflection method was applied to study the effects of acid solution on both a terrestial and aquatic plants Egeria and Cerastium, which are common aquatic plant and terrestial weed respectively. A probe beam from a He-Ne laser was passed through a vicinity of a leaf of the plants, which were put in culture dishes filled with acid solutions. Deflection signals of the probe beam were monitored and compared for acid solutions with different pH values. The results of Egria showed that the deflection signals changed dramatically when pH values of acid solutions were 2.0 and 3.0, while little at pH of 4.0 and 5.0. For Cerastium when pH were below 3.0, deflection signals changed greatly with time at the begining. After a certain period of time, deflection signals changed little with time. When pH value was above 4.0, deflection signals of Cerastium were still changing with time even after 20 hours. The results suggested that the damage threshold of pH was between 3.0 and 4.0 for both the land and aquatic plants. 相似文献
Paddy soil and irrigation water are commonly contaminated with hexavalent chromium [Cr(VI)] near urban industrial areas, thereby threatening the safety of agricultural products and human health. In this study, we develop a porous and high specific area bone char (BC) to support nanoscale zero-valent iron (nZVI) and apply it to remediate Cr(VI) pollution in water and paddy soil under anaerobic conditions. The batch experiments reveal that BC/nZVI exhibits a higher removal capacity of 516.7 mg/(g?nZVI) for Cr(VI) than nZVI when normalized to the actual nZVI content, which is 2.8 times that of nZVI; moreover, the highest nZVI utilization is the nZVI loading of 15% (BC/nZVI15). The Cr(VI) removal efficiency of BC/nZVI15 decreases with increasing pH (4 – 10). Coexisting ions (phosphate and carbonate) and humic acid can inhibit the removal of Cr(VI) with BC/nZVI15. Additionally, BC exhibits a strong advantage in promoting Cr(VI) removal by nZVI compared to the widely used biochar and activated carbon. Our results demonstrate that reduction and coprecipitation are the dominant Cr(VI) removal mechanisms. Furthermore, BC/nZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(VI) in paddy soil, as compared to nZVI. These findings provide a new effective material for remediating Cr(VI) pollution from water and soil. 相似文献
Abstract Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis. 相似文献
Environmental Science and Pollution Research - The correlation coefficient can calculate paired correlations among different ecological indicators as a whole, but it cannot calculate the specific... 相似文献
Flow cytometry (FCM) has been widely used in multi-parametric assessment of cells in various research fields, especially in environmental sciences. This study detected the metabolic activity of Escherichia coli and Staphylococcus aureus by using an FCM method based on 5-cyano-2,3-ditolyltetrazolium chloride (CTC); the accuracy of this method was enhanced by adding SYTO 9 and 10%R2A broth. The disinfection effects of chlorine, chloramine, and UV were subsequently evaluated by FCM methods. Chlorine demonstrated stronger and faster destructive effects on cytomembrane than chloramine, and nucleic acids decomposed afterwards. The metabolic activity of the bacteria persisted after the cytomembranewas damaged as detected using CTC. Low-pressure (LP) UV or medium-pressure (MP) UV treatments exerted no significant effects on membrane permeability. The metabolic activity of the bacteria decreased with increasing UV dosage, and MP-UV was a stronger inhibitor of metabolic activity than LP-UV. Furthermore, the membrane of Gram-positive S. aureus was more resistant to chlorine/chloramine than that of Gram-negative E. coli. In addition, S. aureus showed higher resistance to UV irradiation than E. coli.
