自然光条件下光自芬顿/PMS协同体系处理新污染物的实验设计

为强化学生对新污染物处理理论和实验技能的掌握,设计了光自芬顿/过氧单硫酸盐(PMS)协同体系在自然光条件下对新污染物的强化降解实验。利用水热法和浸渍法制备改性氮化碳空心球MoS_(2)/TCN_(Cl-S)(P),以四环素(TC)作为新污染物代表,构建了光自芬顿/PMS协同体系,基于其耦合效应,提高在自然光条件下污染物的降解效率。结果表明,光自芬顿/PMS体系对TC在120min内的降解率可以达到80%,较不引入PMS的光自芬顿体系提高了30%。其原因在于光自芬顿反应中产生的H_(2)O_(2)与PMS发生协同作用,产生了更多的·O_(2)^(-)、SO_(4)^(-)·和^(1)O_(2)等活性自由基,从而提高了TC的降解效率。该实验设计体系有助于促进学生对高级氧化技术的掌握,为学生科研创新能力培养体系的构建提供参考。

基于隧道实测试验的南京市机动车污染物排放特征研究

为深入研究水下特长公路隧道机动车尾气污染物的排放及分布特征,对南京应天大街长江隧道的交通特征、环境参数和污染物排放质量浓度进行实测研究。采用摄像采集法统计隧道交通特征,结果表明:车辆交通数据与环境数据均呈现明显的日周期变化规律,早高峰车流量显著大于晚高峰,车速与车流量呈负相关。夜间测试结果表明:1)隧道内部污染物质量浓度沿行车方向的变化趋势为先增后减,由于隧道呈现V形的地势特点,PM_(2.5)质量浓度峰值出现在V形底部;2)受到隧道出口风机开启的影响,CO质量浓度峰值出现位置较PM_(2.5)稍有滞后。昼间测试时风机关闭,污染物质量浓度峰值出现在隧道出口,早高峰期间隧道出口CO和PM_(2.5)的质量浓度峰值分别为31.0 mg/m^(3)和145μg/m^(3),分别为质量浓度限值的3.1倍和2倍。采用皮尔逊(Pearson)相关系数法对各相关参数进行相关性检验,CO质量浓度与汽油车数量呈强正相关,PM_(2.5)质量浓度与柴油车数量呈强正相关,2种污染物质量浓度均与风速呈强负相关。

周期性干旱下桂花滞尘能力的变化及其生理响应

干旱的反复发生会导致植物自身产生胁迫记忆,进而会对植物的滞尘能力产生影响,然而,干旱胁迫记忆如何影响植物的滞尘效率及植物的生理响应和适应尚未明确。通过向开顶式气室(OTCs)内输送机动车尾气,停止供水达到干旱,分别设置尾气胁迫组(P)、干旱胁迫组(D)、双胁迫组(PD)和对照组(CK)4个处理组。每个周期性胁迫设置为期12 d,恢复期也为12 d。结果表明,桂花叶片表面滞尘量在P组下由S1周期的33.77μg·cm^(-2)下降到S3的21.32μg·cm^(-2),PD组下由S1周期的38.08μg·cm^(-2)下降到S3的25.70μg·cm^(-2);蜡质层滞尘量在P组呈显著性下降(P<0.001),在PD组中下降不显著。植物体内抗氧化酶活性随着周期处理而逐渐减小,可溶性糖含量先上升后下降,叶绿素含量与颗粒物在第2阶段呈显著负相关,第3周期并无显著相关性。表明反复干旱下提高了植物生理对胁迫的适应性,说明植物的胁迫记忆可以帮助植物更好地应对再次到来的胁迫。

UV/PMS和UV/H_(2)O_(2)降解偶氮染料橙黄G的对比研究

随着社会的发展与人民生活的需求,染料被广泛应用于纺织、印刷与皮革加工等工业生产当中,因而产生了大量富含染料的印染废水。其中,偶氮染料在染料生产与使用市场中占比最高,亟需高效的技术来消除此类毒害污染物。本文以橙黄G为例,深入对比分析了UV/PMS和UV/H_(2)O_(2)两种紫外高级氧化工艺对偶氮染料废水的降解与矿化效能。结果表明,中性条件下UV/PMS工艺更具优势,当氧化剂浓度为5 mmol/L,OG质量浓度为50 mg/L时在20 min内能去除100%的橙黄G与46.4%的TOC。

面向灰霾减缓的寒地城市规划应对策略——基于三维景观环境的定量研究

城市灰霾污染日益突出,该问题在寒地城市的采暖季表现更为显著,这通常与城市三维形态、污染源、交通、气象条件等关联密切。聚焦于寒地城市三种颗粒物的空间分布特征,探讨颗粒物分布和扩散的影响机制及规划应对策略。对沈阳四环内典型主干道路颗粒物浓度开展监测,并借助ArcGIS平台以及街景图片测算城市三维景观环境,采用机器学习和结构方程模型分析气象、交通、三维景观和污染源四类要素与颗粒物浓度间的关系。结果表明:温度和湿度等气象因子对颗粒物污染的影响最大;绿视率和天空可见度等三维景观因子也是主要影响因素。调控策略包括适当增加街道高宽比,提升界面围合度,天空开阔度以0.5左右为宜,并构建城市通风廊道以减少污染物的聚集和沉积。

基于机器感知与学习的空气颗粒物智能检测、识别与预警方法研究综述

随着空气污染问题的不断加剧,准确检测和及时预警空气颗粒物(particulate matter,PM)的重要性日益突出。传统方法依赖专业设备,不适用于实时检测。与传统方法相比,基于机器感知与学习的方法体现出技术优势,具有可实时检测、准确性高等优点。因此,对近几年的基于机器感知与学习的PM智能检测、识别与预警方法进行详细综述。首先,对PM的标准和来源进行介绍;然后,从检测、识别和预警这3个方面详细总结了各类方法,并对比各方法的特点和性能,其中,基于机器学习和深度学习的方法在各研究中取得了较大进展;最后,总结全文主要内容,并提出当前领域面临的挑战以及未来的重点研究方向。未来的研究应该继续关注技术创新和数据质量,以实现更好的空气质量监测和管理。

净化臭氧和颗粒物复合大气污染的城市绿化树种筛选

随着城市化和工业化进程不断加快,春夏季臭氧(O_(3))污染和秋冬季颗粒物(PMs)污染等复合大气污染问题成为困扰我国各大城市的环境难题,严重威胁城市森林的碳汇潜力和净化空气等生态系统服务功能。筛选既具有较强吸收O_(3)和PMs能力且具有较低植源性挥发性有机化合物(BVOCs)释放量的抗性树种,是当今维持城市森林生态功能和人类福祉的重要保障。文章通过整合已发表的文献数据,运用权重赋值法和综合因子分析,解析我国常见386种绿化树种的O_(3)吸收能力、PMs吸附能力、BVOCs释放速率以及复合效应。结果表明:侧柏、圆柏和毛白杨表现出较强的O_(3)和PMs吸收、吸附能力和较低的BVOCs释放量,可作为综合抗性能力较强的城市绿化树种进行推广;悬铃木、鹅掌楸和枫香表现出较弱的O_(3)抗性和PMs吸附能力且BVOCs释放速率较高,不适宜作为城市绿化树种栽植。因此,在适地适树的基础上,城市绿化需要综合考虑树种景观布局和下垫面大气污染的组分和严重程度,选择适宜的绿化树种进行绿化布局,最大限度地发挥绿化树种在城市建设中的生态效益。

Progress of Air Pollution Control in China and Its Challenges and Opportunities in the Ecological Civilization Era

China’s past economic growth has substantially relied on fossil fuels,causing serious air pollution issues.Decoupling economic growth and pollution has become the focus in developing ecological civilization in China.We have analyzed the three-decade progress of air pollution controls in China,highlighting a strategic transformation from emission control toward air quality management.Emission control of sulfur dioxide(SO2)resolved the deteriorating acid rain issue in China in 2007.Since 2013,control actions on multiple precursors and sectors have targeted the reduction of the concentration of fine particulate matter(PM2.5),marking a transition to an air-quality-oriented strategy.Increasing ozone(O3)pollution further requires O3 and PM2.5 integrated control strategies with an emphasis on their complex photochemical interactions.Fundamental improvement of air quality in China,as a key indicator for the success of ecological civilization construction,demands the deep de-carbonization of China’s energy system as well as more synergistic pathways to address air pollution and global climate change simultaneously.

Characterizing PM_2.5Pollution of a Subtropical Metropolitan Area in China

The chemical and physical characteristics of PM2.5, especially their temporal and geographical variations, have been explored in metropolitan Hangzhou area (China) by a field campaign from September 2010 to July 2011. Annual average concentrations of PM2.5 and PM10 during non-raining days were 106 - 131 μg.m-3 and 127 - 158 μg.m-3, respectively, at three stations in urban breathing zones, while corresponding concentrations of PM2.5 and PM10 at an urban background station (16 mabove ground level in a park) were 78 and 104 μg.m-3, respectively. For comparison, the annual average PM10 concentration at a suburban station (5 mAGL) was 93 μg.m-3. Detailed chemical analyses were also conducted for all samples collected during the campaign. We found that toxic metals (Cd, As, Pb, Zn, Mo, Cu, Hg) were highly enriched in the breathing zones due to anthropogenic activities, while soluble ions (, , ) and total carbon accounted for majority of PM2.5 mass. Unlike most areas in China where sulfate was several times of nitrate in fine PM, nitrate was as important as sulfate and highly correlated with ammonium during the campaign. Thus, a historical shift from sulfate-dominant fine PM to nitrate-dominant fine PM was documented.

Characteristics of air pollution events over Hotan Prefecture at the southwestern edge of Taklimakan Desert, China

Hotan Prefecture is located at the southwestern edge of Taklimakan Desert, the world＇s largest shifting sand desert, of China. The desert is one of the main sources for frequent sand-dust weather events which strongly affect the air quality of Hotan Prefecture. Although this region is characterized by the highest annual mean PMlo concentration values that are routinely recorded by environmental monitoring stations across China, both this phenomenon and its underlying causes have not been adequately addressed in previous researches. Reliable pollutant PM_10 data are currently retrieved using a tapered element oscillating microbalance （TEOM） 1400a, a direct real-time monitor, while additional concentration values including for PM_2.5, sulfur dioxide （SO_2）, nitrogen dioxide （NO_2）, carbon monoxide （CO） and ozone （O_3） have been collected in recent years by the Hotan Environmental Monitoring Station. Based on these data, this paper presents a comparison of the influences of different kinds of sand-dust weather events on PM_10 （or PM_2.5） as well as the concentrations of other gaseous pollutants in Hotan Prefecture. It is revealed that the highest monthly average PM_10 concentrations are observed in the spring because of the frequent occurrence of three distinct kinds of sand-dust weather events at this time, including dust storms, blowing dust and floating dust. The floating dust makes the most significant contribution to PM_10 （or PM_2.5） concentration in this region, a result that differs from eastern Chinese cities where the heaviest PM_10 pollution occurs usually in winter and air pollution results from the excess emission of local anthropogenic pollutants. It is also shown that PM_10 concentration varies within wpical dust storms. PM_10 concentrations vary among 20 dust storm events within Hotan Prefecture, and the hourly mean concentrations tend to sharply increase initially then slowly decreasing over time. Data collected from cities in eastern China show the opposite with the hourly mean PM_10 （or PM_2.5） concentration tending to slowly increase then sharply decrease during heavy air pollution due to the excess emission of local anthropogenic pollutants. It is also found that the concentration of gaseous pollutants during sand-dust weather events tends to be lower than those cases under clear sky conditions. This indicates that these dust events effectively remove and rapidly diffuse gaseous pollutants. The analysis also shows that the concentration of SO_2 decreases gradually at the onset of all three kinds of sand-dust weather events because of rapidly increasing wind velocity and the development of favorable atmospheric conditions for diffusion. In contrast, changes in O_3 and NO_2 concentrations conformed to the opposite pattern during all three kinds of sand-dust weather events within this region, implying the inter transformation of these gas species during these events.

Seasonal to interannual prediction of air pollution in China:Review and insight

Complex air pollution problems have resulted in considerable adverse impacts on the environment,human health,and economy in China.However,owing to strict regulations since 2013,the air quality has been greatly improved.Now,the prevention of air pollution has entered a critical stage in combination with climate change mitigation in China.Accurate seasonal to interannual prediction of air pollution(haze,surface 03,and sandstorms) could support the government in planning for air pollution control on an annual basis.Scientists from all over the world have made great progress in understanding climate change and the variability of air pollution and associated physical mechanisms in China,which has provided a scientific basis for the development of climate prediction of air pollution.This paper reviews the progress made in air-pollution climate prediction,and gives some critical insights including update of predictand,change of predictability,and development of coupled model.

Outdoor air pollution as a possible modifiable risk factor to reduce mortality in post-stroke population

Outdoor air pollution is a known risk factor for mortality and morbidity.The type of air pollutant most reliably associated with disease is particulate matter（PM）,especially finer particulate matter that can reach deeper into the lungs like PM_（2.5）（particulate matter diameter 〈 2.5 μm）.Some subpopulations may be particularly vulnerable to PM pollution.This review focuses on one subgroup,long-term stroke survivors,and the emerging evidence suggesting that survivors of a stroke may be at a higher risk from the deleterious effects of PM pollution.While the mechanisms for mortality are still under debate,long-term stroke survivors may be vulnerable to similar mechanisms that underlie the well-established association between PM pollution and cardiovascular disease.The fact that long-term stroke survivors of ischemic,but not hemorrhagic,strokes appear to be more vulnerable to the risk of death from higher PM pollution may also bolster the connection to ischemic heart disease.Survivors of an ischemic stroke may be more vulnerable to dying from higher concentrations of PM pollution than the general population.The clinical implications of this association suggest that reduced exposure to PM pollution may result in fewer deaths amongst stroke survivors.

Numerical simulation of an extreme haze pollution event over the North China Plain based on initial and boundary condition ensembles

The North China Plain often su ers heavy haze pollution events in the cold season due to the rapid industrial development and urbanization in recent decades.In the winter of 2015,the megacity cluster of Beijing Tianjin Hebei experienced a seven-day extreme haze pollution episode with peak PM2.5(particulate matter(PM)with an aerodynamic diameter≤2.5μm)concentration of 727μg m 3.Considering the in uence of meteorological conditions on pollu-tant evolution,the e ects of varying initial conditions and lateral boundary conditions(LBCs)of the WRF-Chem model on PM2.5 concentration variation were investigated through ensemble methods.A control run(CTRL)and three groups of ensemble experiments(INDE,BDDE,INBDDE)were carried out based on difierent initial conditions and LBCs derived from ERA5 reanalysis data and its 10 ensemble members.The CTRL run reproduced the meteorological conditions and the overall life cycle of the haze event reasonably well,but failed to capture the intense oscillation of the instantaneous PM2.5 concentration.However,the ensemble forecasting showed a considerable advantage to some extent.Compared with the CTRL run,the root-mean-square error(RMSE)of PM2.5 concentration decreased by 4.33%,6.91%,and 8.44%in INDE,BDDE and INBDDE,respectively,and the RMSE decreases of wind direction(5.19%,8.89%and 9.61%)were the dominant reason for the improvement of PM2.5 concentration in the three ensemble experiments.Based on this case,the ensemble scheme seems an e ective method to improve the prediction skill of wind direction and PM2.5 concentration by using the WRF-Chem model.

Economic Valuation of Health Impact of PM_(10) Pollution in Beijing from 2001 to 2006

In light of the practical need for research to inform policy in Beijing,this study evaluates the economic cost of the impact of PM 10 pollution in Beijing from 2001 to 2006,taking health as the main impact,and mortality as the main outcome.Based on the literature review,this study adopts relatively conservative parameters as the basis for calculating the health impacts.It concludes that nearly 30%of mortality among registered residents above age 30 in Beijing can be attributed to PM 10 pollution,and that the economic cost equals 0.8%-1.2%of the city's GDP over the same period.This is lower than the results of previous studies,but still high enough to warrant a commitment to solve the city's air pollution problem.

A new approach to spatial source apportionment of haze pollution in large scale and its application in China

Long-lasting expansion of haze pollution in China has already presented a stern challenge to regional joint prevention and control. There is an urgent need to enlarge and reconstruct the coverage of joint prevention and control of air pollution in key area. Air quality models can identify and quantify the regional contribution of haze pollution and its key components with the help of numerical simulation, but it is difficult to be applied to larger spatial scale due to the complexity of model parameters. The time series analysis can recognize the existence of spatial interaction of haze pollution between cities, but it has not yet been used to further identify the spatial sources of haze pollution in large scale. Using econometric framework of time series analysis, this paper developed a new approach to perform spatial source apportionment. We applied this approach to calculate the contribution from spatial sources of haze pollution in China, using the monitoring data of particulate matter(PM_(2.5)) across 161 Chinese cities. This approach overcame the limitation of numerical simulation that the model complexity increases at excess with the expansion of sample range, and could effectively deal with severe large-scale haze episodes.

The Pollution Character Analysis and Risk Assessment for Metals in Dust and PM_(10) around Road from China

INTRODUCTION In recent years, with the gradual improvement of road construction, the rapid increase of the number of motor vehicles, vehicle emissions and the current poor vehicle performance, poor vehicle maintenance, higher emission factor and so on, air pollution caused by the traffic issues becomes the focus of people attention. The harmful substances are gradually accumulated to atmosphere particles surrounding roads due to dust particles （soil dusts, road dusts, construction dusts）, coal emissions, industrial emissions, vehicle emissions, biomass burning, secondary particles, which has a certain harmful influence to the atmosphere, soil and plants surrounding roads.

Health Impact Assessment of Air Pollution in Some Regions in Albania

Air is the ocean we breathe. Air supplies us with oxygen which is essential for our bodies to live. 99.9% air is nitrogen, oxygen, water vapor and inert gases. Human activities can release substances into the air, some of which can cause problems for humans, plants and animals. There are several main types of pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and ＂holes＂ in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment. The age and health condition are more important also at the response opposite the pollution of air. During the last decade in our country such as result of freely population movement, development and growth of their industrial activities, growth of vehicle number, collapse of roadway infrastructure etc., an increase of air quality pollution is evident. In this study, we exhibited the causers, such as increasing of number of the old cars, which is an important factor of the air pollution and, at the same time, we exhibited the pollution indicators of the air quality, such as PM I 0, total dust, dust levels outdoors and indoors, which are in the high levels. These factors indicated on human health. We have observed the health indicators, especially lung diseases such as bronchial asthma with higher percentage, chronic bronchitis and lung cancer. There was consistency in the finding that relates the acute increases in urban air pollution and the short-term health effects or patients suffering from chronic obstructive pulmonary diseases.

Environmental Pollution and Economic Growth in China: A Test of the Environmental Kuznets Curve

We apply a two pronged approach to analyze the presence of Environmental Kuznets Curve, EKC, in three types of emissions in the People’s Republic of China from 1994 to 2014: a structural breakpoint analysis and a model based test. We apply it to PM2.5, industrial waste and domestic water pollution time series, and find evidence of EKC in all three types of emissions that require appropriate policy.

Study on the Current Situation and Source Apportionment of PM_(2.5) Pollution in China

In this paper,using concentration data of PM2. 5in 2013 in China and referring to a lot of literature,we preliminary studied the pollution of fine particulate matter and summarized PM2. 5source apportionment in the key cities in China. Our results showed that PM2. 5showed significant spatial and temporal distribution; high surface concentrations of PM2. 5concentrated mainly in the North China Plain,the Sichuan Basin,Yangtze River Delta and other regions; the average annual concentration of PM2. 5was about 80μg / m3 in North China Plain; Seasonal changes in the concentration of PM2. 5was winter > spring > autumn > summer; fired sources,industrial sources,vehicle exhaust were the major sources of PM2. 5; motor vehicle exhaust mostly contributed 10%- 30% to PM2. 5. This review provides a fundamental understanding of PM2. 5source apportionment and serves as an important reference for future source apportionment studies to be widely conducted in China.

Air Pollution in Major Chinese Cities: Some Progress, But Much More to Do

Background: Ambient (outdoor) air pollution has been implicated as a major cause of acute cardiovascular and pulmonary illnesses and increased risk for acute and chronic effects after chronic exposures, including mortality and morbidity. In 2008, due to persistent health concerns about its workforce and their dependents, the US Mission in China began monitoring air quality at the US Embassy in Beijing. Subsequently, monitoring stations were also established at US consulates at Shanghai (2011), Guangzhou (2011), Chengdu (2012), and Shenyang (2013). Objectives: To determine whether there have been definable trends in air quality in these five Chinese cities. Methods: Air monitoring results from each locale for accumulated PM2.5 particulate matter were calculated hourly. Accumulated data were organized, culled using a standardized set of heuristics, and analyzed for trends. Results: China’s capital city, Beijing, experienced decreased PM2.5 from 2013 through 2015, but no significant long-term downward trend from 2008 through 2015. Shanghai has not shown any definable air quality trend since 2012. Chengdu experienced some improvement in air quality since 2013, but none discernible from 2012 through 2015. Guangzhou had generally better air quality, and a downward trend since 2012. Shenyang experienced increasingly severe air pollution from 2013 through 2015. Conclusion: There appear to have been recent tangible, though modest, improvements in air quality in three large Chinese cities: Beijing, Chengdu, and Guangzhou, but no apparent progress in Shanghai, and a worrisome decline in air quality observed in Shenyang. Despite recent progress, there is a long way to go before even the cities which show improvement reach Chinese standards.