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911.
The role of phenolic groups in the interaction of natural organic matter (NOM) with metal hydroxides was investigated with ATR-FTIR spectroscopy and adsorption tests by employing a series of dihydroxybenzoic acids (DHBAs) as the NOM surrogates and aluminum hydroxide as the adsorbent. All DHBAs examined in this study were found to be adsorbed on aluminum hydroxide by forming inner-sphere complexes. Carboxylic groups governed the complexation of DHBAs with aluminum hydroxide at low pH or in cases when the two hydroxyl groups were not adjacent to each other and neither of them was ortho to the carboxylic group. The involvement of the phenolic groups, ortho to another phenolic group or ortho to the carboxylic groups, in the complexation increased with increasing pH as the deprotonation of phenolic groups was easier at higher pH. The presence of phenolic groups increased the electron density of the carboxylic groups and facilitated the inner-sphere complexation of the carboxylic groups with metal hydroxide. The correlation between the pKa values and the amount of organic acid adsorbed on the aluminum hydroxide revealed that the adsorption of DHBAs at acidic pH was largely dependent on the surface chelate formation rather than on the electronic effect. 相似文献
912.
913.
Using estimates of land suitable for restoration in woodlands, grasslands, and deserts, as well as estimates of the rate at
which restoration can proceed, we estimate that carbon storage in these biomes can range up to 0.8 billion tons of carbon
per year (Gt C/yr), for a combination of land management strategies. This corresponds to a reduction in atmospheric buildup
of 0.5 Gt C/yr, which represents up to 15% of the average annual atmospheric carbon buildup in the next century, 3.5 Gt C/yr,
assuming the IPCC 92d scenario. A global strategy for reducing atmospheric carbon dioxide concentration will require the implementation
of multiple options. The advantage of carbon storage in restored drylands is that it comes as a side benefit to programs that
are also justifiable in terms of land management. 相似文献
914.
Mehrez Samaali Michael D. Moran Vronique S. Bouchet Radenko Pavlovic Sophie Cousineau Mourad Sassi 《Atmospheric environment (Oxford, England : 1994)》2009,43(32):4873-4885
The influence of chemical initial conditions and chemical lateral boundary conditions (CLBCs) on long-term regional air quality model simulations was investigated using outputs from an annual simulation of the year 2002 on a North American domain. This simulation was carried out using the AURAMS regional air quality model. It was subdivided into three multi-month segments with two overlap periods (May 15–30 and September 1–30) to allow the segments to be run in parallel. For this approach to work, model predictions had to match very closely by the end of the two-week and four-week overlap periods. The time required for the values of daily domain-average surface PM2.5 concentration to match for the two simulation segments associated with each of the two overlap periods was four and six days, respectively. For individual locations within the model domain, however, the required spin-up period was as much as nine days, considerably longer than the 2–4-day spin-up period usually assumed in the literature. For ozone, on the other hand, the daily domain-average surface ozone concentration values did not converge for either overlap period. A zero-gradient CLBC had been used for all run segments and species. When a time-invariant CLBC for ozone was used instead, the daily domain-average surface ozone concentration values behaved more realistically and did converge after fewer than three days. A similar improvement was also obtained for individual locations, but with spin-up periods of up to nine days. Model chemical spin-up time thus seems to be dependent on the species considered, the time required for the influence of the inflow boundaries to reach all locations within the domain, and the impact of local emissions sources. These results suggest the use of a spin-up period of longer than one week for a large (continental) domain and long-term simulation of PM2.5 and O3 rather than the 2–4 days commonly assumed in the literature. 相似文献
915.
Wun-Cheng Wang 《Journal of the American Water Resources Association》1974,10(4):662-671
ABSTRACT: The adsorption of phosphate on particulate matter from the Illinois and Spoon Rivers was investigated. Adsoprtion reached equilibrium after 5 to 6 days and adsorption isotherms were linear for both constant and varying amounts of particulate matter. Adsorption was maximum at pH 8.3 – 8.4 and minimum at 6.0. Rates of adsorption were influenced by the equilibrium concentration of phosphate-P and were essentially the same for the Illinois and Spoon Rivers. However, the quantity of phosphate-P adsorbed per unit weight of particulate matter differed for the two streams with that in the Illinois River exhibiting an adsorption capacity 7 times that of the Spoon River. 相似文献
916.
Fridtjof Unander 《Natural resources forum》2005,29(4):377-391
The International Energy Agency (IEA), together with the International Atomic Energy Agency (IAEA), UN‐DESA, Eurostat and the European Environmental Agency, has recently published a comprehensive joint‐agency overview of energy indicators for sustainable development. The IEA's contribution to this publication is based on the IEA energy indicator approach. This approach has been developed and used by the IEA over a number of years. The indicators advocated by the IEA are relatively disaggregated to allow for meaningful analysis of sustainability issues in the energy sector. Using a decomposition approach helps reveal the causal links between human/economic driving forces, energy use and emissions. This article presents examples of IEA's work with indicators and an overview of the methodology used, including an explanation of the link to sustainable development. It also provides an example of a simplified indicator analysis of India, to illustrate the importance of improved data systems in developing indicators that can provide meaningful policy analysis. 相似文献
917.
矿业固废淋溶物对地下环境的污染控制研究进展 总被引:4,自引:0,他引:4
初步探讨了矿业生产所产生的固体废物(煤矸石、矿渣和尾矿等)在水的淋溶和其他介质的作用下产生的有毒有害物质对地下环境(土壤和水)的污染机制,重点论述了有毒有害物质(重金属、有机污染物等)含量分配,尤其是有机污染物对地下水环境影响。针对其污染特点,提出了相应解决办法及今后需做的重点工作。 相似文献
918.
Gwebu TD 《Environmental management》2003,31(3):0348-0354
Based on government and other relevant documentation, this paper explores the conceptual linkage between population, development,
and waste management in Botswana and the implications of this relationship for global climate change. Population is increasing,
albeit at a decreasing rate. Spatially, the population is becoming more and more concentrated as the rates and level of urbanization
increase. Economic growth has remained consistently high. The combined effect of population dynamics and economic development
are having a noticeable imprint on the environment in the form of increased waste generation. Poor waste management poses
a real threat to environmental sustainability in general and climate change in particular because of inadequate technology,
weak institutional mechanisms to enforce regulations, and low levels of sensitization among the public to deal with the problem.
Mitigation measures are suggested to minimize the negative effects of waste management on climate change. 相似文献
919.
Combustion of Tyre Pyrolysis Oil 总被引:6,自引:0,他引:6
P.T. Williams R.P. Bottrill A.M. Cunliffe 《Process Safety and Environmental Protection》1998,76(4):291-301
920.
麦杆烟雾中半挥发性有机物的定性检测 总被引:1,自引:0,他引:1
城郊农村含湿量较高的麦杆就地焚烧,造成环境空气严重污染。本文采用模拟无组织排放污染源TSP采样的方法,通过美国惠普公司生产的气相色谱—质谱联用仪对经前处理的样品进行分离及定性检测,确认了十四种有机化合物 相似文献