Evaluation of the First Phase of Sulfur Dioxide and Nitrogen Oxides Provisions of the 1990 Clean Air Act: A Plant-Based Approach

Electric power generating plants that use coal were among the key targets of Title IV of the 1990 Clean Air Act. Under the first phase of the act, 110 coal-fired electric power plants were required to reduce their sulfur dioxide emissions by 1995 and nitrogen oxide emissions by 1996. Phase 2 of the act requires even greater reduction of sulfur dioxide emissions by 2000 and nitrogen oxide emissions by 2008. This study examines whether the 107 targeted plants (three plants went off-line) have achieved the desired sulfur dioxide and nitrogen oxide emission levels. The analysis of sulfur dioxide is based on data from 1990, 1995, and 1999. The findings show that although sulfur oxide increased by 3% from 1995 to 1999, it decreased by 45% over the 1990–1999 period at the firm level for the targeted firms. The findings also indicate that the overall reduction in sulfur dioxide was achieved by utilizing low sulfur coal and by purchasing emission allowances. So far as nitrogen oxides are concerned, there has been a reduction of 14% over the 1990–1999 period, of which 7% was achieved during the 1995–1999 period. An evaluation of emissions at the plant level indicates that several plants do not meet the emissions level for sulfur dioxide or nitrogen oxides. These results provide a mixed scorecard for reduction in emissions both for sulfur dioxide and nitrogen oxides. Even though there is reduction in the emissions on an overall basis at the firm level, several plants that have not been able to reduce emissions deserve special attention to meet the goals of the act in reducing emissions.     

The benefits and costs of reducing emissions from the electricity sector

Recent federal policy proposals to reduce emissions of sulfur dioxide (SO(2)), nitrogen oxides (NO(x)), and mercury from the US electricity sector promise important improvements in air quality and reductions in acid deposition. The cost of achieving these reductions depends on the form and stringency of the regulation. In this research, we analyze the economic benefits and costs of the US Environmental Protection Agency's (EPA's) Clean Air Interstate Rule (CAIR) as characterized in the supplemental rule proposed in June 2004, and the Clean Air Mercury Rule (CAMR) as proposed in February 2004. The assessment integrates a model of the electricity sector, two models of atmospheric transport of air pollutants, and a model of environmental and public health endpoints affected by pollution. We model explicitly the emissions of SO(2), NO(x), mercury and carbon dioxide (CO(2)) and the effects of changes in emissions of SO(2) and NO(x) on environmental and public health. The manner in which mercury emissions are regulated will have important implications not only for the cost of the regulation, but also for emission levels for SO(2) and NO(x) and where those emissions are located. We find the economic benefits of CAIR and CAMR are far greater than the costs. Recent estimates of benefits of reductions in mercury and acidification indicate that our model captures the lion's share of quantifiable benefits. We also find that the EPA would have been justified on economic grounds in pursuing additional SO(2) emissions reductions beyond the requirements of CAIR.     

Economic and Environmental Analysis of Retrofitting a Large Office Building with Energy-Efficient Lighting Systems

An evaluation of the economic and environmental costs and benefits that would result if the Zorinsky Federal Building, located in Omaha, Nebraska, USA, converted its current lighting system to a more energy-efficient system (i.e., joined the EPA's Green Lights Program) was conducted. Lighting accounts for 20–25 percent of all electricity sold in the United States. Costs considered in the study included the cost of retrofitting the building's existing lighting system and the cost of disposal of the current lamps and ballast fixtures. Benefits included a reduction of electric utility costs and a reduction of emissions of SO₂, NO _x , CO₂, and CO from electric utility power plants. Environmental and health issues for air pollutant emissions were also addressed. The results showed that significant reductions in utility bills as well as reductions in air emissions would result from a major building converting to a more energy efficient lighting system. The results showed that conversion of this large building would reduce SO₂ emissions by 14.6 tons/yr and NO _x emissions by 6.3 tons/yr. In addition, the conversion would reduce annual energy costs by approximately $114,000.     

Environmental Management of Sulfur Trioxide Emission: Impact of SO3 on Human Health

The major contributors to global acidification are sulfur oxides and nitrogen oxides emitted mostly by the burning of fossil fuels. From the scientific point of view, it is necessary to make a clear distinction between sulfur dioxide and sulfur trioxide when referring to sulfur oxides. These two air pollutants have different properties. This paper reports the following aspects: the strong effect of sulfur trioxide on local human health (a case study of asthma in Yokkaichi), the problem of corrosion caused by sulfur trioxide, the difference in analytical methods for determining sulfur dioxide concentrations and sulfur trioxide concentrations, and the difference in removal methods for sulfur dioxide and sulfur trioxide. An important initiative at the third European conference of environment ministers was that the issue of human health related to local air pollution should be given priority over that of global pollution. The declines in the emissions of sulfur dioxide and nitrogen oxides have mainly been effective in reducing acidification due to long-range transport. The reduction in sulfur trioxide may be more effective in improving local human health mentioned in the initiative.     

论长江经济带大气污染防治的若干问题与防治对策

长江经济带是世界上最大的内河产业带和制造业基地,建设长江经济带是新时期中国三大国家发展战略之一,积极、有效地保护长江经济带生态环境具有非常重要的战略意义。本研究从识别突出的大气污染防治问题入手,深入分析大气污染的主要驱动力产业与能源结构,以问题为靶向,提出长江经济带的大气污染防治策略。研究结果发现,占国土面积21%的长江经济带排放了全国34%的二氧化硫、32%的氮氧化物、28%的烟粉尘、44%的挥发性有机物、43%的氨,单位面积污染物排放强度是全国平均水平的1.3~2.1倍,污染物排放远超环境容量。长江经济带126个城市中,6项主要大气污染物年平均浓度全部达标的城市比例不到1/3。颗粒物是影响城市达标的主要污染物。长江经济带产业结构偏重和能源消费以煤为主,是造成大气污染排放量的主要源头,是大气污染的主要驱动力。以解决突出的大气环境问题为核心,将环境质量作为大气污染防治的底线,持续推进空气质量改善,重点措施上,从大气污染驱动力着手,提出优化产业与能源结构、深化多污染物协同控制、推进区域联防联控等大气污染防治对策建议。     

超低排放背景下煤电机组氨管控存在的问题及对策探析

近年来,我国大气污染防治成效显著,煤电机组超低排放政策实施对此做出了突出贡献。氮氧化物是煤电机组超低排放中的重要控制指标之一。然而,受现有氮氧化物排放监测和喷氨控制技术的精度、反馈时效等因素的限制,为提高脱硝效率保证性,电厂在实际运行中存在过量喷氨现象,未完全反应的氨进入大气后可能造成二次颗粒物增加。针对这一现象,本文回顾了我国火电行业氮氧化物排放标准和治理措施的演化及实施效果,对煤电机组氨排放现状和存在的问题进行了深入分析,提出在推进氮氧化物超低排放过程中应开展脱硝过量喷氨现状调研,鼓励企业开展脱硝系统优化,加强复杂烟气环境下氨监测技术研发,完善脱硝氨逃逸日常环境监管,推动氨排放全生命周期转化规律基础研究和大气环境效应评估,进一步提升煤电机组超低排放政策实施的综合环境效益,也对其他行业超低排放政策推进起到示范作用。     

Control strategies for vehicular NOx emissions in Guangzhou, China

Guangzhou is a city in southern China that has experienced very rapid economic development in recent years. The city's air has very high concentrations of various pollutants, including sulphur dioxide (SO₂), oxides of nitrogen (NOx), ozone (O₃) and particulate. This paper reviews the changes in air quality in the city over the past 15 years, and notes that a serious vehicular-related emissions problem has been superimposed on the traditional coal-burning problem evident in most Chinese cities. As NOx concentrations have increased, oxidants and photochemical smog now interact with the traditional SO₂ and particulate pollutants, leading to increased health risks and other environmental concerns.
Any responsible NOx control strategy for the city must include vehicle emission control measures. This paper reviews control strategies designed to abate vehicle emissions to fulfill the city's air quality improvement target in 2010. A cost-effectiveness analysis suggests that, while NOx emission control is expensive, vehicular emission standards could achieve a relatively sizable emissions reduction at reasonable cost. To achieve the 2010 air quality target of NOx, advanced implementation of EURO3 standards is recommended, substituting for the EURO2 currently envisioned in the national regulations. Related technical options, including fuel quality improvements and inspection/maintenance (I/M) upgrades (ASM or IM240), are assessed as well.     

Urban sprawl and air quality in large US cities

This study presents the results of a paper of urban spatial structure and exceedances of the 8-h national ambient air quality standard for ozone in 45 large US metropolitan regions. Through the integration of a published index of sprawl with metropolitan level data on annual ozone exceedances, precursor emissions, and regional climate over a 13-year period, the association between the extent of urban decentralization and the average number of ozone exceedances per year, while controlling for precursor emissions and temperature, is measured. The results of this analysis support the hypothesis that large metropolitan regions ranking highly on a quantitative index of sprawl experience a greater number of ozone exceedances than more spatially compact metropolitan regions. Importantly, this relationship was found to hold when controlling for population size, average ozone season temperatures, and regional emissions of nitrogen oxides and volatile organic compounds, suggesting that urban spatial structure may have effects on ozone formation that are independent of its effects on precursor emissions from transportation, industry, and power generation facilities.     

“排污权”和“碳排放权”交易的减污降碳协同效应研究——基于污染治理和政策管理的双重视角

全面系统地评估排污权交易和碳排放权交易的减污降碳协同效应，对于进一步发挥应对气候变化和大气污染治理的协同效应、推进全国统一生态环境市场建设具有重要意义。本文基于污染治理和政策管理的双重视角，采用多时点双重差分和倾向得分匹配，分别检验排污权交易和碳排放权交易的减污和降碳效应；并在此基础上，研究三种政策情景下（排污权交易、碳排放权交易以及组合政策）的协同减排效应差异。研究表明，从污染治理视角，排污权交易和碳排放权交易均显著降低了二氧化硫和二氧化碳排放量，实现了减污降碳的协同效应；从政策协同管理视角，在减少二氧化硫污染方面，组合政策比各类政策的单独实施更为有效；在降低二氧化碳排放方面，碳排放权交易比排污权交易和组合政策更为有效。因此，在推进气候变化应对和大气污染治理机制融合的进程中，应有所侧重地推进碳排放权交易和排污权交易组合使用。     

张掖市城区采暖期环境空气中污染物分布特征分析

以张掖市甘州区城区采暖期2008—2012年5年环境空气质量数据为主,对采暖期污染物变化状况及污染物分布情况进行分析。张掖市冬季采暖主要以燃煤为主,能源结构不合理、锅炉污染严重、工业企业结构不合理以及交通污染等原因,使得冬季采暖期间张掖市甘州区城区环境空气中主要污染物为二氧化硫、可吸入颗粒物、二氧化氮,采暖期间污染物浓度随时问呈正态分布特征。结合污染特点,提出调整能源结构、利用清洁能源、加大监管力度等建议,以期改善张掖市采暖期的环境空气质量。     

Urban air pollution and atmospheric diffusion research in China

Air pollution has become a serious problem in China as a result of that country's efforts in the last 30 years to become a great industrial power. The burning of coal, which currently provides over 70% of all China's energy needs, is a major source of air pollution. Because Chinese coal is high in sulfur and ash content and because most combustion devices in China have low efficiencies, SO₂ and particulate emissions are a serious problem and are comparable to or exceed those found in many countries that are much more industrialized. Although most coal is burned in North China, acid precipitation is most severe in South China because of the lack of buffering loess dust found in the former region.The Chinese government has already taken major steps to mitigate air pollution, such as relocating polluting industries, supplying coal with lower sulfur content, using gas instead of coal for residential heating, and levying fines on industries that exceed pollution standards. Atmospheric environmental impact assessment (AEIA) is also required for all major new projects. This article describes three types of mathematical diffusion models and field and wind-tunnel experiments that are used in such assessments.The Chinese authorities believe that a range of technological, managerial, locational, and behavioral changes must be effected before the air of Chinese cities can be significantly improved.     

Can China control the side effects of motor vehicle growth?

Motor vehicle growth in China is the fastest in the world. This is placing great strain on the urban environment and causing a rapid increase in oil imports and motor vehicle carbon dioxide emissions. To deal with the environmental and health effects of air pollution, China has adopted a strong motor vehicle pollution control programme and imposed limits on fuel consumption of new light duty vehicles. The article will review these problems and programmes. Special focus will be given to the need to reduce sulphur levels in both gasoline and diesel fuel.     

A human ecological assessment of air quality management: A convergence in economic and ecological thinking?

Traditional air pollution management practices are examined using the human ecological framework adopted by Boyden and others (1981) in their study of Hong Kong—the biohistorical or biosocial approach. The subsequent analysis of current air quality management practices assesses their effectiveness in protecting the overall health of both humans and the natural environment. The uncertainties inherent in air pollution management practices which emerge highlight the need to reduce emissions rather than rely on scientific knowledge to define clean air. The assessment also clearly defines roles for research in various areas such as atmospheric models, health effects, and environmental damage. The final recommendations emphasize the need for the introduction of such incentives to reduce emissions as economic instruments and warn against using health information to define clean air. Health and environmental damage information can, however, be used in risk assessment strategies together with atmospheric dispersion models.     

Strategies for Emission Reduction of Air Pollutants Produced from a Chemical Plant

Various air pollution control (APC) techniques were employed in order to reduce emissions of air pollutants produced from chemical plants, which have many different chemical production facilities. For an emission reduction of acid gases, this study employed a method to improve solubility of pollutants by decreasing the operating temperature of the scrubbers, increasing the surface area for effective contact of gas and liquid, and modifying processes in the acid scrubbers. To reduce emission of both amines and acid gases, pollutant gas components were first separated, then condensation and/or acid scrubbing, depending on the chemical and physical properties of pollutant components, were used. To reduce emission of solvents, condensation and activated carbon adsorption were employed. To reduce emission of a mixture gases containing acid gases and solvents, the mixed gases were passed into the first condenser, the acid scrubber, the second condenser, and the activated carbon adsorption tower in sequence. As a strategy to reduce emission of pollutants at the source, this study also employed the simple pollution prevention concept of modification of the previously operating APC control device. Finally, air emissions of pollutants produced from the chemical plants were much more reduced by applying proper APC methods, depending upon the types (physical or chemical properties) and the specific emission situations of pollutants.     

Efficient regional ozone control strategies for the eastern United States

When environmental regulatory bodies formulate control plans, it is incumbent upon them to try to achieve the stated goals in an economically efficient manner. The US Environmental Protection Agency (EPA) is presently developing regulations to limit the influence of transported ozone on areas that are having difficulty meeting the ambient air quality standard. EPA has proposed stringent control measures for emissions of nitrogen oxides (NOx) in 22 states of the eastern US. The strategy would necessitate the use of selective catalytic reduction or similar high-performance technology on almost all major power plants in the region, as well as extensive controls on industrial sources. This paper suggests several alternative approaches that would achieve equal or better environmental improvement at lower cost. These include focusing control efforts on sources closer to the North-east Corridor, pushing controls on close-in sources to a higher level of technology performance, and relaxing the stringency of requirements for states remote from ozone problem areas. All the approaches examined are two to three times more cost-effective than EPA's proposed approach in the North-east Corridor.     

Air assimilative capacity-based environment friendly siting of new industries--a case study of Kochi region, India

Air pollution has become a matter of grave concern, particularly in mega-cities and urban areas, where the situation is alarming and becoming more and more severe day-by-day and warrants, therefore, careful planning to facilitate future industrial development. Site selection, with the objective of minimizing adverse environmental impacts based on environmental criteria is a vital prerequisite, particularly for air polluting industries. In order to locate any air polluting industry, the assimilative capacity of the region needs to be assessed carefully and planned accordingly, so that the receiving environment is not adversely affected. Assimilative capacity of a region/airshed, widely represented through the ventilation coefficient by many researchers in the past, does not give a clear picture about the amount of emission load that can be assimilated in a given region. The ventilation coefficient, at best, can only present a broad picture about the air pollution dispersion potential (low, medium or high) of the region. A modified approach, which utilizes air quality modelling as a tool to estimate the maximum allowable emission load that a region can assimilate without violating the stipulated standards, has been used for estimating the assimilative capacity of the air environment. Details of this approach have been presented in this paper through a case study carried out for the Kochi region, located in the Kerala State of India. A variety of emission and meteorological scenarios have been considered and critical emission loads have been estimated. This approach shall provide necessary technical guidance to the environmental regulatory authorities as well as to the industries in planning environment friendly industrial development.     

Historical Analysis of SO<Subscript>2</Subscript> Pollution Control Policies in China

Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China’s national sulfur dioxide (SO₂) emissions have been the highest in the world for many years, and since the 1990s, the territory of China’s south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO₂ emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO₂ control in China, we found that Chinese SO₂ control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China’s environmental goals, however, has been made difficult by China’s economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological “campaign” or “storm” that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced.     

Passive monitoring of nitrogen dioxide in urban air: a case study of Durban metropolis, South Africa

To devise and implement strategies to manage the quality of urban air, a metropolis needs air pollution data on which an air quality management plan can be formulated. Although air pollutants can come from several sources, many reports suggest that nitrogen dioxide from motor vehicle emissions is the major contributor to air pollution in cities. Since vehicles stop or move slowly through traffic intersections, concentrations of nitrogen dioxide (NO(2)) are expected to be relatively high at these sites. Inexpensive Ogawa passive samplers were placed at selected traffic intersections in the Durban Metropolis to trap the NO(2) which was then analysed by a sensitive laboratory-based method. The data obtained by this method was compared with data from sophisticated system comprising an active sampler cum on-line chemiluminescence detector. The sampling was done over a twelve month period to cover all seasons. Statistical analysis of the data showed that there was no significant difference between the means for the two methods. This study has established that an Ogawa passive sampler may be used as an economical and reliable collector for NO(2) in ambient air under varying climatic conditions. Further, the analysis method using a UV-Visible spectrophotometer was sensitive enough to detect NO(2) at the 10-20 ppb level. The cost of the method should be well within the budgets of most municipalities and it would motivate them to develop policies to alleviate traffic congestion.     

火电厂氮氧化物控制标准、政策分析及研究

制订污染物的排放标准及控制政策是治理环境污染的主要措施之一，世界各国针对火电厂氮氧化物（NOx）排放量分别制订了适合各国国情的控制政策及排放标准。通过对美国、欧盟及日本等世界主要发达国家及地区火电厂氮氧化物排放控制对策的分析，提出了对我国火电厂氮氧化物排放控制政策的建议。