CO2 capture performance of bi-functional activated bleaching earth modified with basic-alcoholic solution and functionalization with monoethanolamine: isotherms, kinetics and thermodynamics

CO_2 capture performance of bifunctional activated bleaching earth(ABE) was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction(XRD), Brunauer–Emmett–Teller(BET), Caron-Hydrogen-Nitrogen analysis(CHN), Fourier transform infrared(FT-IR) and thermal gravimetric analysis(TGA). The CO_2 capacity was enhanced via basic-modification and monoethanolamine(MEA) loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30 wt.%MEA loading(SAB-30) showed the highest CO_2 capture capacity, but this was decreased with excess MEA loading( 30 wt.%). At a 10%(V/V) initial CO_2 concentration feed, the maximum capacity of SAB-30 increased from 2.71 mmol/g at 30℃(without adding moisture to the feed) to 3.3 mmol/g at 50℃ when adding 10%(V/V) moisture to the feed. Increasing the moisture concentration further reduced the maximum CO_2 capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture CO_2 even in a 100%(V/V) initial CO_2 concentration feed. A maximum CO_2 capacity of5.7 mmol/g for SAB-30 was achieved at 30℃. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO_2 capture capacity. Avrami's equation and Toth's isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO_2 capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO_2 capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.     

The effects of temperature and resource availability on denitrification and relative N2O production in boreal lake sediments

Anthropogenic environmental stressors(like atmospheric deposition,land use change,and climate warming) are predicted to increase inorganic nitrogen and organic carbon loading to northern boreal lakes,with potential consequences for denitrification in lakes.However,our ability to predict effects of these changes is currently limited as northern boreal lakes have been largely neglected in denitrification studies.The aim of this study was therefore to assess how maximum potential denitrification and N_2O production rates,and the relationship between the two(relative N_2O production),is controlled by availability of nitrate(NO_3~-),carbon(C),phosphorus(P),and temperature.Experiments were performed using the acetylene inhibition technique on sediments from a small,nutrient poor boreal lake in northern Sweden in 2014.Maximum potential denitrification and N_2O production rates at 4°C were reached already at NO_3~-additions of 106–120 μg NO_3~-–N/L,and remained unchanged with higher NO_3 amendments.Higher incubation temperatures increased maximum potential denitrification and N_2O production rates,and Q10 was somewhat higher for N_2O production(1.77) than for denitrification(1.69).The relative N_2O production ranged between 13% and 64%,and was not related to NO_3~-concentration,but the ratio increased when incubations were amended with C and P(from a median of 16% to 27%).Combined,our results suggests that unproductive northern boreal lakes currently have low potential for denitrification but are susceptible to small changes in NO_3 loading especially if these are accompanied by enhanced C and P availability,likely promoting higher N_2O production relative to N_2.     

2005年-2014年新疆生态足迹的计算及分析

随着社会经济的发展和人口密度不断增加的双重压力下,新疆维吾尔自治区的生态环境质量问题也日益突出,这就妨碍了区域经济的可持续发展.生态足迹是评估生态环境质量的重要指标,文章根据新疆维吾尔自治区2005年-2014年自然资源、能源消费、人口等数据,计算得出的生态足迹、生态环境承载能力和生态赤字结果显示,新疆维吾尔自治区自然资源供应和需求之间的关系不均衡,新疆生态足迹和生态承载力并不是处于最佳可持续性状态.     

Water footprint: methodologies and a case study for assessing the impacts of water use

The methodologies, approaches and indicators for assessing the impacts of freshwater usage are still evolving. The development of the water footprint concept has been an important step in this direction but the existing methodologies mainly assess the quantity of water used rather than the related impacts. Although there is a recognised need to consider the latter, particularly on a life cycle basis, the difficulty is that there are little or no reliable data on water usage in life cycle databases; furthermore, there is no agreed life cycle impact assessment method for estimating impacts related to freshwater use. However, there have been some methodological developments which propose methods for inventory modelling and impact assessment for water use in life cycle assessment. This paper reviews some of these approaches and discusses their strengths and limitations through a case study, which considers the impacts of freshwater consumption from corn-derived ethanol produced in 12 different countries. The results show a huge variation in the results between different methods and demonstrate the need for a standardised methodology for assessing the impacts of water use on a life cycle basis. Specific recommendations for further research in this field have been made accordingly.     

软包装印刷的有机废气净化和溶剂回收工艺研究

为了促进企业开展节能减排和资源回用,在车间选取了一条干式复合线进行废气净化和溶剂回收及利用工艺研究,使用乙酸乙酯作为粘胶剂的稀释剂,废气净化和溶剂回收采用吸附浓缩+冷凝回收工艺,溶剂脱水提纯采用渗透汽化膜分离工艺.结果表明,这两种工艺组合十分适合干式复合线的溶剂回收和溶剂脱水提纯,处理装置具有溶剂回收率高、纯度好、运行...     

2005～2009年南京市二氧化碳排放特征研究

采用IPCC报告(2006版)提供的计量方法与碳含量缺省值,对南京市能源消费碳排放进行了计量研究.结果表明:从2005～2009年,CO2排放总量从8.05×107t增加到1.02×108t,人均CO2排放量从11.7 t/a增加到13.2 t/a,但CO2排放强度持续降低,从3.34 t/万元下降到2.41 t/万元...     

Carbon balance of an intensively grazed temperate pasture in two climatically contrasting years

Grazed grasslands occupy 26% of the earth's ice free land surface and are therefore an important component of the global C balance. In New Zealand, pastoral agriculture is the dominant land use and recent research has shown that soils under intensive dairy pastures have lost large amounts of carbon (∼1000 kg C ha⁻¹ y⁻¹) during the past few decades. The objective of this research was to determine the net ecosystem carbon balance (NECB) of an intensively grazed dairy pasture in New Zealand. Net ecosystem CO₂ exchange (NEE) was measured using an eddy covariance (EC) system from 1 January 2008 to 31 December 2009. Other C imports (feed) and exports (milk, methane, leaching, and harvested biomass) were calculated from farm production data and literature values. During 2008 there was a one in 100 year drought during summer/autumn, which was followed by a very wet winter. There were no prolonged periods of above or below average rainfall or soil moisture in 2009, but temperatures were consistently lower than 2008. The severe summer/autumn drought during 2008 caused a loss of CO₂ to the atmosphere, but annual NEE remained negative (a CO₂ sink, −1610 ± 500 kg C ha⁻¹), because CO₂ lost during the drought was regained during the winter and spring. The site was also a net CO₂ sink during 2009 despite the colder than usual conditions (−2290 ± 500 kg C ha⁻¹). Including C imports and exports in addition to CO₂ exchange revealed that the site was a C sink in both years, with a NECB of 590 ± 560 kg C ha⁻¹ in 2008, and 900 ± 560 kg C ha⁻¹ in 2009. The C sequestration found in this study is in agreement with most other Northern Hemisphere EC studies of grazed pastures on mineral soils, but is not consistent with the large C losses reported for soils under dairy pastures throughout New Zealand. In the current study (like many other EC studies) the influence of climatic conditions and management practices on the annual C balance was only semi-quantitatively assessed. An extended period of EC measurements combined with modelling is required to more accurately quantify the effect of different climatic conditions on the annual C balance, and the influence of different management practices needs to be quantified using specifically designed studies (such as paired EC towers), so that practices which minimise C losses and maximise C sequestration can be identified.     

基于IPAT模型的天津市经济增长与资源环境负荷分析

以协调经济、资源和能源三者之间的关系,实现城市的可持续发展为目标,基于IPAT模型,参考《天津统计年鉴》,定量分析天津市1999—2008年经济增长与能源消耗之间的关系,并将生态足迹模型引入其中,对资源能源的利用效率进行评估,得出以下结论：10a中,天津市经济增长给环境带来的负效应超过了科学技术进步带来的正面效应;人均GDP从1999年的1.54万元增加到2008年的5.55万元,同比增加了2.6倍,同时,单位GDP生态足迹从0.62hm2/万元到0.30hm2/万元,同比下降了52%;针对天津市资源能源的利用效率问题提出有关对策和措施。     

Land Area Eligible for Afforestation and Reforestation within the Clean Development Mechanism: A Global Analysis of the Impact of Forest Definition

Within the United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol, countries have significant latitude to define a forest. The most important parameter affecting area designated as forest is the minimum crown cover which can be set between 10 and 30%. The choice will have implications for the amount of land available in a country for afforestation and reforestation activities within the Clean Development Mechanism (CDM-AR). In this paper, we present an analysis of the regional differences in land availability for CDM-AR projects. We then examine how the choice of a high or low threshold value for crown cover will affect the area available for CDM activities and how the limitations imposed by this element of the definition compares to other factors that are likely to limit CDM activities. Results represent a global analysis that included all countries not included in Annex I of the Kyoto Protocol, and examined the effect on land availability of a range of crown cover thresholds ranging from 10–30%. Of the 140 Non-Annex One countries, 107 countries were found to have a potential for CDM-AR projects. Asia had the largest amount of combined area suitable for CDM-AR at the 10% crown cover threshold level. However, at 30%, South America had the greatest amount of land available, and a large change in available land area, which increased by almost five times compared to what was available at the 10% threshold. The area available in Africa increased by a factor of 5.5. Central America showed the largest increase, to almost 10 times more at the 30% threshold. By contrast, within Asia, the area increase was comparatively less, but still the area nearly doubled. Globally, a low threshold of 10% crown cover excluded almost 2/3 of the land identified that was eligible at 30%, over 5 million km². The spatial analyses showed not only the effects of the choice of the crown cover criterion, but also where the land was available for CDM activities within each country at different thresholds. Protected areas account for 10–20% of the CDM-AR eligible area in most countries.     

基于生态足迹模型的土地利用生态环境分析方法研究

随着经济和社会的发展,生态环境问题正日益受到各国政府和社会的关注。而作为人类一切活动载体的土地,其生态环境显得愈加重要。生态足迹法是一种定量度量生态经济发展协调状况及发展能力的有效方法。本文是基于Bicknell的投入产出模型探讨了对土地利用生态环境进行动态分析的方法,进一步研究了一定区域在进行对外贸易时,对土地资源的开发利用和消费,为衡量土地生态环境和可持续发展状况,作出科学的决策提供定量工具。并从土地利用角度出发,提出了减少生态赤字一些对策。