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1.
大气甲醛(HCHO)是臭氧(O3)和细颗粒物(PM2.5)二次组分的关键前体物,在大气光化学反应和二次污染形成过程中扮演着重要角色,并存在致癌性.然而,当前对大气HCHO排放来源认识存在不足,制约了二次污染形成机制研究和污染防控策略制定.采用排放因子和成分谱结合方法,建立2006~2020年广东省HCHO排放趋势清单,识别了广东省主要HCHO排放来源和排放时空演变特征.结果表明,2006~2020年期间广东省HCHO排放量在3.9~5.6万t区间波动,整体呈现极微弱的下降趋势;生物质燃烧源是广东省重要HCHO排放源,而受到管控措施的显著影响,其排放量占比从2006年的58%降至2020年的27%;溶剂使用源的HCHO排放则逐渐突显,2020年占比增长至28%,并成为广东省首要排放源,其中塑料制品和沥青铺路是主要贡献行业.移动源中以柴油作为燃料的工程机械和货车也是HCHO重要排放来源;虽然珠三角和非珠三角地区对广东省HCHO排放量贡献相当,但空间分布结果表明HCHO排放热点区域分别集中于珠三角中心区域和非珠三角的东西两角,这是由于珠三角主要来源为溶剂使用源和移动源,而非珠三角主要受生物质燃烧源影响.因此,未来应进一步加强珠三角中心区域的工业和移动源减排以及粤西地区的生物质燃烧监管.  相似文献   
2.
Urbanization and mass movement of the population from rural areas and small cities to megacities have led to environmental, economic, and social problems in Iran. In dealing with these challenges, assessing resource and environmental carrying capacity (RECC) is considered an effective method to leverage space and capital to achieve sustainable development. This study aimed to rank the provincial RECC in Iran. Toward this purpose, environmental indices were generated from remotely sensed and statistical census data. Then, the provinces were scored in terms of environmental, economic, and infrastructural carrying capacities, and RECC using the mean variance analysis method. Results demonstrated that in most areas, there is no relationship between economic and infrastructural capacities and development. Statistically, a correlation coefficient of −0.53 between economic and environmental carrying capacities indicated excessive use of environmental capacities. Moreover, the spatial distribution pattern of environmental, economic, and infrastructural carrying capacity was entirely heterogeneous between the provinces; there was a northeast–southwest pattern in terms of infrastructural capacity and an economic pattern from north to south. The distribution pattern of RECC is most consistent with the environmental capacity, pointing at the high weight of the indicators of the RECC model. In conclusion, this research offers a new vision for policymakers and provides a theoretical and applicable framework for implementing sustainable strategies in land-use planning. It is recommended that the RECC concept and tools can be used not only for planning but also for measuring the efficiency of spatial development programs and establishing land balances in the region.  相似文献   
3.
Despite long-standing knowledge of the benefits of riparian buffers for mitigating nonpoint source pollution, many streams are unprotected by buffers. Even landowners who understand ecological values of buffers mow riparian vegetation to the streambank. Do trends in rural riparian conditions reflect the development of riparian forest science? What motivates residential riparian management actions? Using high-resolution orthoimagery, we quantified riparian conditions and trends between 1998 and 2015 in the rural upper Little Tennessee River basin in Macon County, North Carolina and explored how landowners view riparian zone management and riparian restoration programs. Buffer composition in 2015 was as follows: no buffer (32.5%), narrow (19.3%), forested (26.7%), shrub (7.2%), and intermediate (7.0%). Relative to 1998, the greatest decrease occurred in the no buffer class (−17.7%, 46 km) and the largest increases occurred in the shrub (+72.5%, 20 km) and narrow (12.6%, 14 km) classes. Forested buffer marginally increased. Semi-structured interview data suggest that landowners prioritize recreational and scenic aspects of riparian buffers over ecological functions such as filtration and bank stabilization. Riparian restoration programs might be made more enticing to non-adopters if outreach language appealed to landowner priorities, design elements demonstrated intentional management, and program managers highlighted areas where ecological goals and landowner values align.  相似文献   
4.
有机磷酸酯(OPEs)作为溴代阻燃剂的替代品,在生产生活中被广泛使用,其环境污染和毒性效应受到广泛关注.梳理中国七大典型流域水体中OPEs的含量水平和分布特征,计算中国成人、青少年和儿童的OPEs日均饮水暴露量,对其健康风险进行评估,并通过蒙特卡洛模拟方法评价了结果的可靠性.检索整理了12种OPEs对水生生物的毒性效应浓度,构建物种敏感度分布(SSD)曲线,对生态风险进行评估.结果表明,低等暴露水平下,七大流域ΣOPEs的第5百分位浓度为52.61 ng·L-1;中等暴露水平下,七大流域ΣOPEs的中位浓度为499.74 ng·L-1,磷酸三氯乙酯(TCEP)、磷酸三乙酯(TEP)和磷酸三(1,3-二氯-2-丙基)酯(TDCP)为主要污染物;高等暴露水平下,七大流域ΣOPEs的第95百分位浓度为1904.4 ng·L-1,是其中等暴露水平的3.8倍,长江流域的ΣOPEs浓度最高.健康风险评估表明,不同人群通过饮用水暴露于OPEs的非致癌风险均在可接受范围内.磷酸三甲酯(TMP)、磷酸三异丁酯(TiBP)和TCEP是致癌风险的主要贡献者.生态风险评估结果表明,TCEP在高等暴露水平下存在中等生态风险;磷酸三正丁酯(TnBP)在中等暴露水平下存在中等生态风险,在高等暴露水平下,有较高生态风险;磷酸三苯酯(TPhP)在低中高3种暴露水平下的风险商均大于1,有较高生态风险,需要重点关注.  相似文献   
5.
Water quality is a critical challenge in Asia in the context of growing industrialization, urbanization, and climate change. Nature-based solutions (NbS) could play an important role in reducing urban water pollution, while generating multiple co-benefits that could make cities more liveable and resilient. In this regard, a number of pilot and demonstration projects have been set up to explore their potential across cities in Asia. Their effectiveness and impacts, however, have not been adequately documented, thus how they can be sustained, replicated and up-scaled remain poorly understood. This study aims to contribute to addressing this challenge by co-developing an integrated assessment framework and employing it to understand how existing evaluations of NbS in the region can be improved. It focuses specifically on a set of nature-based solutions that have been employed for water treatment across six cities in Southeast Asia (two in each Sri Lanka, the Philippines, and Vietnam), namely, floating wetlands, constructed wetlands and maturation ponds. The study also suggests specific methodologies for capturing a set of core indicators considered relevant for assessing the effectiveness and capturing the multi-faceted impacts of the examined NbS.  相似文献   
6.
The iron and steel industry is not only an important foundation of the national economy, but also the largest source of industrial air pollution. Due to the current status of emissions in the iron and steel industry, ultra-low pollutant emission control technology has been researched and developed. Liquid-phase proportion control technology has been developed for magnesian fluxed pellets, and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets (80%) for the first time in China to realize source emission reduction of SO2 and NOx. Based on the characteristics of high NOx concentrations and the coexistence of multiple pollutants in coke oven flue gas, low-NOx combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur. Based on the characteristics of co-existing multiple pollutants in pellet flue gas, selective non-catalytic reduction (SNCR) coupled with ozone oxidation and spray drying adsorption (SDA) was developed, which significantly reduces the operating cost of the system. In the light of the high humidity and high alkalinity in flue gas, filter materials with high humidity resistance and corrosion resistance were manufactured, and an integrated pre-charged bag dust collector device was developed, which realized ultra-low emission of fine particles and reduced filtration resistance and energy consumption in the system. Through source emission reduction, process control and end-treatment technologies, five demonstration projects were built, providing a full set of technical solutions for ultra-low emissions of dust, SO2, NOx, SO3, mercury and other pollutants, and offering technical support for the green development of the iron and steel industry.  相似文献   
7.
Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO2·, NO3· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O3 and NO2, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O3 and PM2.5 was analyzed by scenario simulation.  相似文献   
8.
In most of the world's building material industries, the control of flue gas pollutants mainly focuses on a single pollutant. However, given the large capacity and high contribution of China's building materials industry to global air pollution, the need to develop multi-pollutant emission reduction technology is urgent. Recently, China has focused on reducing the emissions of flue gas pollutants in the building materials industry, established many key research and development projects, and gradually implemented more stringent pollutant emission limits. This project focuses on the most recent advances in flue gas emission control technology in China's building materials industry, including denitration, dust removal, desulfurization, synergistic multi-pollutant emission reduction, and the construction of pilot research and demonstration projects for pollutant removal in several building material industries. On this basis, revised pollutant limits in flue gas emitted in China's building material industry are proposed.  相似文献   
9.
Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NOx emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m3 for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m3 for the annual average of PM2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NOx emission reductions. If the ozone concentration target were reduced to 155 µg/m3, deep NOx emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m3, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM2.5 and O3 pollution in China.  相似文献   
10.
随着建筑结构的发展,上悬窗日益成为城市建筑窗户的选择,但这种通风条件下腔室火灾的发展特性仍缺乏研究。利用1∶8相似比例的缩尺寸腔室火灾实验台,实验研究了上悬窗不同开口尺寸、不同开窗角度下,通风控制的腔室火灾温度发展特性。实验结果表明,通风控制条件下,腔室火灾温度随着上悬窗开口尺寸和开窗角度的增加而增加,并通过能量平衡分析,建立了通风控制条件下,耦合上悬窗尺寸和开窗角度因素的腔室内部火灾温度预测模型。  相似文献   
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