Use of Industrial By‐Products in Urban Roadway Infrastructure

Incorporating the beneficial use of industrial by‐products into the industrial ecology of an urban region as a substitute or supplement for natural aggregate can potentially reduce life cycle impacts. This article specifically looks at the utilization of industrial by‐products (IBPs) (coal ash, foundry sand, and foundry slag) as aggregate for roadway sub‐base construction for the Pittsburgh, Pennsylvania, urban region. The scenarios compare the use of virgin aggregate with the use of a combination of both virgin and IBP aggregate, where the aggregate material is selected based on proximity to the construction site and allows for minimization of transportation impacts. The results indicate that the use of IBPs to supplement virgin aggregate on a regional level has the potential of reducing impacts related to energy use, global warming potential, and emissions of nitrogen oxides (NO_x), sulfur dioxide (SO₂), carbon monoxide (CO), PM₁₀ (particulate matter—10 microns), mercury (Hg), and lead (Pb). Regional management of industrial by‐products would allow for the incorporation of these materials into the industrial ecology of a region and reduce impacts from the disposal of the IBP materials and the extraction of virgin materials and minimize the impacts from transportation. The combination of reduced economic and environmental costs provides a strong argument for state transportation agencies to develop symbiotic relationships with large IBP producers in their regions to minimize impacts associated with roadway construction and maintenance—with the additional benefit of improved management of these materials.     

Contribution of Urban Water Supply to Greenhouse Gas Emissions in China

Greenhouse gas (GHG) emissions from energy use in the water sector in China have not received the same attention as emissions from other sectors, but interest in this area is growing. This study uses 2011 data to investigate GHG emissions from electricity use for urban water supply in China. The objective is to measure the climate cobenefit of water conservation, compare China with other areas on a number of emissions indicators, and assist in development of policy that promotes low‐emission water supply. Per capita and per unit GHG emissions for water supplied to urban areas in China in 2011 were 24.5 kilograms carbon dioxide equivalent (kg CO₂‐eq) per capita per year and 0.213 kg CO₂‐eq per cubic meter, respectively. Comparison of provinces within China revealed that GHG emissions for urban water supply as a percentage of total province‐wide emissions from electricity use correlate directly with the rate of leakage and water loss within the water distribution system. This highlights controlling leakage as a possible means of reducing the contribution of urban water supply to GHG emissions. An inverse correlation was established between GHG emissions per unit water and average per capita daily water use, which implies that water demand tends to be higher when per unit emissions are lower. China's high emission factor for electricity generation inflates emissions for urban water supply. Shifting from emissions‐intensive electricity sources is crucial to reducing emissions in the water supply sector.     

Converting carbon dioxide to high value-added products: Microalgae-based green biomanufacturing

Today's world faces the dual pressure of carbon dioxide (CO₂) emission reduction and an energy crisis. Microalgae, which can use solar energy to convert CO₂ to organic matter, have emerged as a promising and renewable cell factory for producing nutrients, biofuels, and various high value-added compounds (HVACs). They possess numerous advantages, such as high photosynthetic efficiency, fast growth rate, and use of agro-industrial waste and nonagricultural land for cultivation. Microalgae can also effectively remove eutrophic elements (e.g., nitrogen and phosphorus) from wastewater and atmospheric pollutants (e.g., SO_x and NO_x) from flue gas, thus providing great environmental benefits. However, microalgae-based production often faces low productivity, limiting applicability in industrial settings. Genetic and metabolic modifications of certain microalgal strains have proven effective in improving productivity. Here, we review the latest developments regarding the microalgae-based production of platform compounds, biofuels, and other HVACs. Although still in the early exploration stage, the rapid development of gene editing tools, a deeper understanding of the metabolic pathways of microalgae and their regulatory mechanisms, and further optimization of cultivation procedures and photosynthetic efficiency can eventually enable the launch of microalgae-based biomanufacturing for green industrial production. Therefore, this technology is strategically important for solving the current energy crisis problems of excessive CO₂ emissions and environmental pollution. This review provides information about the advancement and development of microalgae-based production over the past two decades and discusses possible future directions in the field.     

Life cycle and matrix analyses for re-refined Oil in Japan

Unstable market systems and consumer preferences for virgin oil have inhibited the development of waste oil re-refining in Japan. In this papery comparative life cycle inventories were developed for re-refining waste oil and for the no-refining case in which the waste oil is incinerated and needs are supplied with virgin oil. Total energy, CO₂, NO_x, and SO₂ emissions were included during the re-refining and consumption (incineration) stages; all are lower in the case of re-refined fuel use. In addition, by using a streamlined LCA matrix, we demonstrate that re-refining waste oil can reduce environmental impacts compared with the case in which virgin oil is chosen.     

Does Size Matter? Scaling of CO2 Emissions and U.S. Urban Areas

Urban areas consume more than 66% of the world’s energy and generate more than 70% of global greenhouse gas emissions. With the world’s population expected to reach 10 billion by 2100, nearly 90% of whom will live in urban areas, a critical question for planetary sustainability is how the size of cities affects energy use and carbon dioxide (CO₂) emissions. Are larger cities more energy and emissions efficient than smaller ones? Do larger cities exhibit gains from economies of scale with regard to emissions? Here we examine the relationship between city size and CO₂ emissions for U.S. metropolitan areas using a production accounting allocation of emissions. We find that for the time period of 1999–2008, CO₂ emissions scale proportionally with urban population size. Contrary to theoretical expectations, larger cities are not more emissions efficient than smaller ones.     

我国典型城市化石能源消费CO2排放及其影响因素比较研究

城市是化石能源消费和CO_2排放的主要区域。分析典型城市化石能源消费CO_2排放特征,明确不同城市CO_2排放动态及主要影响因素的差异,是开展城市减排行动的重要科学依据。采用IPCC推荐方法及中国的排放参数核算11个典型城市2006—2015年间化石能源消费产生的CO_2排放量。根据各城市经济发展和CO_2排放特征将之分为四类:经济高度发达城市(北京、上海、广州)、高碳排放城市(重庆、乌鲁木齐、唐山)、低排放低增长城市(哈尔滨、呼和浩特和大庆)和低排放高增长城市(贵阳、合肥),并运用对数平均迪氏指数法(Logarithmic Mean Divisia Index,即LMDI分解法)对比分析了四类城市CO_2排放量的影响因素。结果表明:(1)研究期内大部分城市CO_2排放总量有所增加,仅北京和广州呈下降趋势,工业部门CO_2排放在城市排放总量及其变化中占据主导地位;四类城市的人均CO_2排放量表现出与排放总量相似的变化趋势;CO_2排放强度整体上表现为经济高度发达城市(均值为0.88 t CO_2/万元)低排放低增长城市(均值为2.82 t CO_2/万元)低排放高增长城市(均值为3.05 t CO_2/万元)高碳排放城市(均值为6.62 t CO_2/万元)。(2)在城市CO_2排放的影响因素中,经济发展和人口规模均是4类城市CO_2排放增长的促进因素,但经济发展效应的累积贡献值大于人口规模效应;能源强度降低是4类城市CO_2排放最主要的抑制因素,且经济高度发达和高碳排放城市的抑制作用强于其他两类城市;对第三产业GDP年平均增速高于第二产业的6个城市来说,产业结构是CO_2排放的抑制因素;能源结构的变化仅对煤炭消费比重较低且降幅较大的北京和广州的CO_2排放是抑制作用,累积贡献值分别为-21.73Mt和-0.03Mt,而对其他城市,特别是高碳排放城市的CO_2排放具有明显的促进作用。     

An integrated approach to improving fossil fuel emissions scenarios with urban ecosystem studies

The future trajectory of fossil fuel emissions is one of the largest uncertainties in predicting climate change. While global emissions scenarios are ultimately of interest for climate modeling, many of the factors that influence energy and fuel consumption operate on a local rather than global level. However, there have been relatively few comprehensive studies of the ecological and socioeconomic processes that will determine the future trajectory of net carbon dioxide (CO₂) emissions at local and regional scales. We conducted an interdisciplinary, whole ecosystem study of the role of climate, urban expansion, urban form, transportation, and the urban forest in influencing net CO₂ emissions in the Salt Lake Valley, Utah, a rapidly urbanizing region in the western U.S. Our approach involved a detailed emissions inventory validated with atmospheric measurements, as well as a system dynamics model of future CO₂ emissions developed in collaboration with local stakeholders. The model highlighted the importance of a positive feedback between urban land development and transportation investments that may strongly affect emissions by amplifying declines in developmental densities and increases in vehicular traffic. Simulations suggested that while doubling the density of tree planting would have a negligible effect on total urban CO₂ emissions, land use and transportation policies that dampen the intensity of the urban sprawl feedback could result in a 22% reduction in CO₂ emissions by 2030 relative to a business as usual scenario. We suggest that by advancing our mechanistic understanding of energy and fuel consumption regionally, this urban ecosystem approach has great potential for improving emissions scenario studies if replicated in other cities and urbanizing regions.     

城市能源利用碳足迹分析——以厦门市为例

城市能源利用碳足迹分析综合考虑直接与间接碳排放,对于深度分析碳排放的本质过程、制定科学全面的碳减排计划具有重要意义。以厦门市为研究案例,应用碳足迹的混合分析方法,对厦门市2009年能源利用碳足迹进行了分析,除了包括传统研究中的城市能源终端利用产生的直接碳排放,还计算了跨界交通和城市主要消耗物质的内含能引起的间接碳排放。研究结果表明:(1)城市边界内的工业、交通、商业等部门的能源消耗产生的直接碳排放(即层次1和层次2)只占到总碳足迹的64%,而一直被忽略的跨界交通和城市主要消耗物质的内含能引起的间接碳排放(层次3)占到36%;(2)在直接碳排放中,工业部门的碳排放贡献率最大,占到直接碳排放的55%,其中化工行业带来的碳排放占到工业部门的25%;(3)在间接碳排放中,跨界交通引起的碳排放占间接碳排放的27%,其中长途道路运输贡献率最大,占跨界交通碳排放的38%;主要材料内含能碳排放占间接碳排的73%,其中燃料的内含能碳排放占总内含能的份额最大,达51%。;(4)从人均碳足迹角度比较,厦门市人均碳足迹和丹佛市的人均直接碳排(层次1+层次2)分别为5.74 t CO2e/人、18.9 t CO2e/人,包含3个层次的人均碳足迹分别为9.01 tCO2e/人、25.3 t CO2e/人,其中跨界交通引起的碳排放均占总碳足迹的10%左右,主要材料的内含能引起的碳排放分别占到总碳足迹的26%、15%;通过国内外典型城市不同层次碳足迹比较可见厦门还是相对低碳的,但有个显著的特点是主要消耗物质的内含碳排放比例较高,这在一定程度上说明了发展中国家城市消耗更多的基础材料,进一步证明了传统核算中忽略的第3层次碳排放核算与管理的重要性。     

LCA of concrete and steel building frames

The effects on the external environment of seven concrete and steel building frames representative of present-day building technology in Sweden were analysed using LCA methodology. Objects of the study included frame construction and supplementary materials. Several-storey offices and dwellings were studied. The functional unit was defined as one average m² of floor area during the lifetime of the building. Inventory data were elaborated for concrete and steel production, the building site, service life, demolition and final disposal. Parameters included were raw material use, energy use, emissions to air, emissions to water and waste generation. The inventory results were presented and evaluated as such, in addition to an interpretation by using three quantitative impact assessment methods. Parameters that weighed heavily were use of fossil fuels, CO₂, electricity, SO_x ² NO_x ² alloy materials and waste, depending on what assessment method was used. Over the life cycle, building production from cradle to gate accounted for about the same contribution to total environmental loads as maintenance and replacement of heat losses through external walls during service life, whereas demolition and final disposal accounted for a considerably lower contribution.     

From Energy to Environmental Analysis

Unsustainable private consumption causes energy and environmental problems. This occurs directly (resource depletion and emissions through using cars for transport) or indirectly (purchase of consumer goods and services for which the production uses energy and emits damaging gases). A hybrid energy analysis proved that indoor energy consumption, mobility, and vacations are the main consumer categories from an energy point of view. Although energy is often used as a proxy for environmental load from private consumption, there are other proxies like methane (CH₄), sulfur oxides (SO_x), and land use. This article describes the results of the extension of the hybrid energy analysis with energy and ten environmental stressors (CH₄, nitrous oxide [N₂O], nitrogen, phosphate, SO_x, nitrogen oxides [NO_x], ammonia [NH₃], nonmethane volatile organic compounds [NMVOCs], particulate matter [PM10], and land use), combined in five impact categories (global warming potential [GWP], acidification, eutrophication, summer smog, and land use). Household consumption was analyzed by dividing Dutch household expenditure into 368 consumer items in 11 categories. The results show that food impacts, in particular, are underestimated when only energy is taken into account. Food makes the highest contribution in three out of five impact categories when all ten stressors are taken into account. Within the food domain, meat and dairy consumer items have the highest environmental impact, about 45% of total food impact on average across all five impact categories. Looking in detail (368 consumer items), there are nine food items in the top ten most‐polluting items. Salad oil and cheese are the most polluting food items.     

Development of life cycle inventories for electricity grid mixes in Japan

Since most industrial processes consume electricity, it is quite important to develop reliable inventory data for electricity. There is, however, a problem that only a few figures concerning emissions related to electricity have been reported. In this work, process models of power plants were developed for the Japanese situation which simulate the mass flows and estimate the missing figures of emissions dependent on technical parameters of the plants and fuels. In Japan, electricity is supplied to the various regions by 10 electric companies. Therefore, life cycle inventories for the electricity grid mixes of the 10 electric companies in 1997 were developed. The functional unit is 1 kWh of electricity distributed to electricity users in each region. The emission of CO₂, SO₂, NO_k, CH₄, CO, non-methane volatile organic compound (NMVOC), dust (all particulates) and heavy metals (Ni, V, As, Cd, Cr, Hg, Pb, Zn) from power stations as well as those from fuel production and transport were investigated. Other pollutants into air, emissions to water, solid wastes, radiation and radioactive emissions from atomic power stations were not included due to a limitation of the available data. Direct CO₂ emissions related to 1 kWh of electricity distributed by companies ranged from 0.21 to 1.0 kg/kWh (average value: 0.38 kg/kWh). Direct emissions of SO₂ and NO_x from power stations related to 1 kWh of electricity are 2.5* 10^-4 and 2.2* 10^-4 kg/kWh on the average, respectively. SO₂ emissions calculated in this work were somehow large compared with those reported by electric companies. Detailed information concerning total sulfur content in oil consumed in each oil-fired power station are required for an exact calculation of SO₂ emissions from oil-fired power stations. In addition, the ratio of sulfur that goes into slag in combustion must be investigated further. The average amounts of CO, CH₄, NMVOC and dust emissions were 5.0*10^-5, 8.2*10^-6, 1.8*10^-5 and 6.8 * 10^-6 kg/kWh, respectively. Heavy metal emissions from power stations were on the order of 10^-9 to 10^-8 kg/kWh. Detailed information concerning heavy metal content in oil and coals consumed in fossil fuel power stations are further required for an improved assessment of heavy metal emissions. Contribution of fuel production and transport to total CO₂ emission was relatively small. On the other hand, contributions of fuel production and transport to total SO₂ and NO_x emissions were relatively large. In the case of CO, NMVOC and dust, emissions in fuel production and transport were predominant to total emissions. Heavy metal emissions into air during production and transport of fuels were on the order of 10/^-8 to 10^-9 kg/kWh.     

A Longitudinal Study of Sick Building Syndrome (SBS) among Pupils in Relation to SO2, NO2, O3 and PM10 in Schools in China

There are fewer longitudinal studies from China on symptoms as described for the sick building syndrome (SBS). Here, we performed a two-year prospective study and investigated associations between environmental parameters such as room temperature, relative air humidity (RH), carbon dioxide (CO₂), nitrogen dioxide (NO₂), sulphur dioxide (SO₂), ozone (O₃), particulate matter (PM₁₀), and health outcomes including prevalence, incidence and remission of SBS symptoms in junior high schools in Taiyuan, China. Totally 2134 pupils participated at baseline, and 1325 stayed in the same classrooms during the study period (2010–2012). The prevalence of mucosal symptoms, general symptoms and symptoms improved when away from school (school-related symptoms) was 22.7%, 20.4% and 39.2%, respectively, at baseline, and the prevalence increased during follow-up (P<0.001). At baseline, both indoor and outdoor SO₂ were found positively associated with prevalence of school-related symptoms. Indoor O₃ was shown to be positively associated with prevalence of skin symptoms. At follow-up, indoor PM₁₀ was found to be positively associated with new onset of skin, mucosal and general symptoms. CO₂ and RH were positively associated with new onset of mucosal, general and school-related symptoms. Outdoor SO₂ was positively associated with new onset of skin symptoms, while outdoor NO₂ was positively associated with new onset of skin, general and mucosal symptoms. Outdoor PM₁₀ was found to be positively associated with new onset of skin, general and mucosal symptoms as well as school-related symptoms. In conclusion, symptoms as described for SBS were commonly found in school children in Taiyuan City, China, and increased during the two-year follow-up period. Environmental pollution, including PM₁₀, SO₂ and NO₂, could increase the prevalence and incidence of SBS and decrease the remission rate. Moreover, parental asthma and allergy (heredity) and pollen or pet allergy (atopy) can be risk factors for SBS.     

Life cycle inventory for electricity generation in China

Background, Goal and Scope The objective of this study was to produce detailed a life cycle inventory (LCI) for the provision of 1 kWh of electricity to consumers in China in 2002 in order to identify areas of improvement in the industry. The system boundaries were processes in power stations, and the construction and operation of infrastructure were not included. The scope of this study was the consumption of fossil fuels and the emissions of air pollutants, water pollutants and solid wastes, which are listed as follows: (1) consumption of fossil fuels, including general fuels, such as raw coal, crude oil and natural gas, and the uranium used for nuclear power; (2) emissions of air pollutants from thermal power, hydropower and nuclear power plants; (3) emissions of water pollutants, including general water waste from fuel electric plants and radioactive waste fluid from nuclear power plants; (4) emissions of solid wastes, including fly ash and slag from thermal power plants and radioactive solid wastes from nuclear power plants. Methods Data were collected regarding the amount of fuel, properties of fuel and the technical parameters of the power plants. The emissions of CO₂, SO₂, NO_x, CH₄, CO, non-methane volatile organic compound (NMVOC), dust and heavy metals (As, Cd, Cr, Hg, Ni, Pb, V, Zn) from thermal power plants as well as fuel production and distribution were estimated. The emissions of CO₂ and CH₄ from hydropower plants and radioactive emissions from nuclear power plants were also investigated. Finally, the life cycle inventory for China’s electricity industry was calculated and analyzed. Results Related to 1 kWh of usable electricity in China in 2002, the consumption of coal, oil, gas and enriched uranium were 4.57E-01, 8.88E-03, 7.95E-03 and 9.03E-08 kg; the emissions of CO₂, SO₂, NO_x, CO, CH₄, NMVOC, dust, As, Cd, Cr, Hg, Ni, Pb, V, and Zn were 8.77E-01, 8.04E-03, 5.23E-03, 1.25E-03, 2.65E-03, 3.95E-04, 1.63E-02, 1.62E-06, 1.03E-08, 1.37E-07, 7.11E-08, 2.03E-07, 1.42E-06, 2.33E-06, and 1.94E-06 kg; the emissions of waste water, COD, coal fly ash, and slag were 1.31, 6.02E-05, 8.34E-02, and 1.87E-02 kg; and the emissions of inactive gas, halogen and gasoloid, tritium, non-tritium, and radioactive solid waste were 3.74E+01 Bq, 1.61E-01 Bq, 4.22E+01 Bq, 4.06E-02 Bq, and 2.68E-10 m³ respectively. Conclusions The comparison result between the LCI data of China’s electricity industry and that of Japan showed that most emission intensities of China’s electricity industry were higher than that of Japan except for NMVOC. Compared with emission intensities of the electricity industry in Japan, the emission intensities of CO₂ and Ni in China were about double; the emission intensities of NO_x, Cd, CO, Cr, Hg and SO₂ in China were more than 10 times that of Japan; and the emission intensities of CH₄, V, Pb, Zn, As and dust were more than 20 times. The reasons for such disparities were also analyzed. Recommendations and Perspectives To get better LCI for the electricity industry in China, it is important to estimate the life cycle emissions during fuel production and transportation for China. Another future improvement could be the development of LCIs for construction and operation of infrastructure such as factory buildings and dams. It would also be important to add the information about land use for hydropower.     

Acidification: its impact on the environment and mitigation strategies

The effect of acidification on ecosystems is reviewed. About 30% of the world land area is acidified mostly by natural processes. Only a small part of it is acidified from pollution which leads to extensive forest and surface water deterioration in Europe and North America. The damage is especially visible in areas of poor soil quality. The acid deposition pattern is characterized, with a special emphasis on Poland. It was shown that strategies for mitigation of ecosystem acidification lead to a decrease of SO₂ emissions due to the use of lower sulphur content fuels and application of desulphurisation methods. Also, a decrease in NO_x emissions is observed due to use of catalysts and application of NO_x removal technologies. However, since about 50% of NO_x emission is from vehicles, this improvement is offset by a continuously increasing vehicle population. The application of liming, forest fertilisation and suitable land use for mitigation of ecosystem acidification is also reviewed.     

Environmental assessment of urban mobility: Combining life cycle assessment with land-use and transport interaction modelling—Application to Lyon (France)

In France, greenhouse gas (GHG) emissions from transport have grown steadily since 1950 and transport is now the main source of emissions. Despite technological improvements, urban sprawl increases the environmental stress due to car use. This study evaluates urban mobility through assessments of the transport system and travel habits, by applying life cycle assessment methods to the results of mobility simulations that were produced by a Land Use and Transport Interactions (LUTI) model. The environmental impacts of four life cycle phases of urban mobility in the Lyon area (exhausts, fuel processing, infrastructure and vehicle life cycle) were estimated through nine indicators (global warming potential, particulate matter emissions, photochemical oxidant emissions, terrestrial acidification, fossil resource depletion, metal depletion, non-renewable energy use, renewable energy use and land occupancy). GHG emissions were estimated to be 3.02 kg CO₂-eq inhabitant⁻¹ day⁻¹, strongly linked to car use, and indirect impacts represented 21% of GHG emissions, which is consistent with previous studies. Combining life cycle assessment (LCA) with a LUTI model allows changes in the vehicle mix and fuel sources combined with demographic shifts to be assessed, and provides environmental perspectives for transport policy makers and urban planners. It can also provide detailed analysis, by allowing levels of emissions that are generated by different categories of households to be differentiated, according to their revenue and location. Public policies can then focus more accurately on the emitters and be assessed from both an environmental and social point of view.     

Using LCA‐based Decomposition Analysis to Study the Multidimensional Contribution of Technological Innovation to Environmental Pressures

This article presents a general framework for macroenvironmental assessment, combining life cycle assessment (LCA) with the IPAT equation, and explores its combination with decomposition analysis to assess the multidimensional contribution of technological innovation to environmental pressures. This approach is illustrated with a case study in which carbon dioxide (CO₂) and nitrogen oxides (NO_x) air emissions from diesel passenger cars in Europe during the period 1990–2005 are first decomposed using index decomposition analysis into technology, consumption activity, and population growth effects. By a second decomposition, the contribution of a specific innovation (diesel engine) is calculated on the basis of the technology and consumption activity effects, through a technological comparison with a relevant alternative and the calculation of the rebound effect, respectively. The empirical analysis for diesel passenger cars highlights the discrepancies between the micro (LCA) and macro (IPAT‐LCA) analytical approaches. Thus, whereas diesel engines present a relatively less‐pollutant environmental product profile than their gasoline counterparts, total CO₂ and NO_x emissions would have increased partly as a consequence of their introduction, mainly driven by the increase in travel demand caused by the induced direct price rebound effect from fuel savings and fuel price differences. The counterintuitive result shows the need for such an analysis.     

Chang impact analysis of level 3 COVID-19 alert on air pollution indicators using artificial neural network

In this study, mean monthly and diurnal variations in fine particulate matters (PM_2.5), nitrate, sulfate, and gaseous precursors were investigated during the Level 3 COVID-19 alert from May 19 to July 27 in 2021. For comparison, the historical data during the identical period in 2019 and 2020 were also provided to determine the effect of the Level 3 COVID-19 alert on aerosols and gaseous pollutants concentrations in Taichung City. A machine learning model using the artificial neural network technique coupled with a kinetic model was applied to predict NO_x, O₃, nitrate (NO₃⁻), and sulfate (SO₄²⁻) to investigate potential emission sources and chemical reaction mechanism. D during the Level 3 COVID-19 alert, a decrease in NO_x concentration due to a decrease in traffic flow under the NO_x-saturated regime was observed to enhance the secondary NO₃⁻ and O₃ formation. The present models were shown to predict 80.1, 77.0, 72.6, and 67.2% concentrations of NO_x, O₃, NO₃⁻, and SO₄²⁻, respectively, which could help decision-makers for pollutant emissions reduction policies development and air pollution control strategies. It is recommended that more long-term datasets, including water soluble inorganic salts (WIS), precursors including OH radicals, NH₃, HNO₃, and H₂SO₄, be provided by regulatory air quality monitoring stations to further improve the prediction model accuracy.     

Effect of flue gas components on succinate production and CO2 fixation by metabolically engineered Escherichia coli

Escherichia coli pfl ldhA ptsG (AFP111) was studied for succinate production in defined medium using trace gases typically found in flue gas; i.e. oxygen (O₂), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO). Following aerobic cell growth, cells were exposed to 50% CO₂ and 3–10% O₂, or 50–300 ppm NO₂, SO₂ or CO during the succinate production phase. Although 3% O₂ did not significantly affect succinate formation, 10% O₂ reduced the final succinate concentration from 33 to 17 g/L, specific productivity from 1.90 to 1.13 mmol/g h and yield from 1.15 to 0.81 mol/mol glucose. The effect of O₂ correlated with the culture redox potential (ORP) with more reducing conditions favoring succinate production. The trace gases NO₂ and SO₂ also reduced the rate of succinate formation by as much as 50%, and led to a greater than twofold increase in pyruvate formation. Similar concentrations of CO showed no effect on succinate production rate or yield. Using synthetic flue gas AFP111 generated 12 g/L succinate with a specific productivity of 0.73 mmol/g h and a yield of 0.65 mol/mol.     

北京市主要建筑保温材料生命周期与环境经济效益评价

在低碳、绿色、环保、生态成为当代城市文明的主题下,建筑保温材料作为建筑节能最主要的解决途径之一备受关注,以北京市75%节能6层模拟住宅为例,利用DeST-h软件计算得出其墙体传热系数K值为0.40 W m-2K-1,节约电量42.31 kW h-1m-2,通过计算可节约标煤17.09 kg/m2,减少CO2排放量42.19 kg/m2,减少SO2排放量1.27 kg/m2,减少NOx排放量0.635 kg/m2,减少煤粉尘排放量11.5 kg/m2,减少煤烟尘排放5.75 kg/m2,环境效益36.66元/m2。并利用生命周期原理进行简化计算出4种常见保温材料岩棉、XPS、EPS和聚氨酯的50a建筑寿命周期中的总能耗分别为6.55×106、6.63×106、6.58×106、6.77×106kJ/m2,其中不同阶段能耗所占的比例从大到小依次为运行能耗生产能耗运输能耗。保温材料资金回收年限、环境效益回收年限和能耗回收年限的大小顺序:聚氨酯XPS≈EPS岩棉,三者顺序基本一致。并对建筑外墙保温材料科学评价与发展趋势进行探讨。     

Decoupling Analysis of Four Selected Countries

We examine decoupling conditions of domestic extraction of materials, energy use, and sulfur dioxide (SO₂) emissions from gross domestic product (GDP) for two BRIC (Brazil, Russia, India and China) countries (i.e., China and Russia) and two Organisation for Economic Co‐operation and Development (OECD) countries (Japan and the United States) during 2000–2007, using a pair of decoupling indicators for resource use (D_r) and waste emissions (D_e) and the decoupling chart, which can distinguish between absolute decoupling, relative decoupling, and non‐decoupling. We find that (1) during 2000–2007, decoupling between environmental indicators and GDP was higher in the two OECD countries as compared with the two BRIC countries. The key reason is that these countries were in different development stages with different economic growth rates. (2) Changes in environmental policies can significantly influence the degree of decoupling in a country. (3) China, Japan, and the United States were more successful in decoupling SO₂ emissions from GDP than in decoupling material and energy use from GDP. The main reason is that, unlike resource use, waste emissions (e.g., SO₂ emissions) can be reduced by effective end‐of‐pipe treatment. (4) The decoupling indicator is different from the changing rate of resource use and waste emissions. If two countries have different GDP growth rates, even though they may have similar values using the decoupling indicator, they may show different rates of change for resource use and waste emissions.