基于大气污染治理形势及其存在问题和措施探究

在近些年的发展中,我国的经济经济水平就叫得到了不断的进步,这与此同时,大气污染问题不断加重。环保部门对于各类问题加大重视力度,除了对各类环境保护相关措施予以颁布之外,也会应用诸多创新型的技术手段,其主要目的在于使得实际的空气质量得以提升,进一步缓解当前大气所存在的污染问题。对我国大气污染相关问题发展趋势,以及在治理过程当中体现出的各类问题进行分析,进行综合性的讨论,形成以下观点,希望能够为我国的大气污染治理工作提供一定程度的参考。

爆破CO的行为规律

爆破ＣＯ不仅危害职工的安全和健康，还污染大气环境。在恫室内的沙土中进行爆破实验，研究ＣＯ的行为规律和迁移速率，结果表明，爆破ＣＯ的行为方程近似为抛物线方程；且随着爆破后时间的增加，时间迁移速率减小，浓度迁移速率和浓度一时间迁移速率基本不变。

Experiment and mechanism investigation on advanced reburning for NO_x reduction:influence of CO and temperature

Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were inves- tigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%~25% reburn heat input, temperature range from 1100 °C to 1400 °C and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 °C and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 °C^1100 °C. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures.

Characteristics and Cause Analysis of Heavy Haze in Changchun City in Northeast China

Northeast China has been reported as having serious air pollution in China with increasing occurrences of severe haze epi- sodes. Changchun City, as the center of Northeast China, has longstanding industry and is an important agricultural base. Additionally, Changchun City has a long winter requiring heating of buildings emitting pollution into the air. These factors contribute to the complex- ity of haze pollution in this area. In order to analyze the causes of heavy haze, surface air quality has been monitored from 2013 to 2015. By using satellite and meteorological data, atmospheric pollution status, spatio-temporal variations and formation have been analyzed. Results indicated that the air quality in 88.9% of days exceeding air quality index （AQI） level-1 standard （AQI 〉50） according to the National Ambient Air Quality Standard （NAAQS） of China. Conversely, 33.7% of the days showed a higher level with AQI 〉 100. Ex- treme haze events （AQI 〉 300） occurred frequently during agricultural harvesting period （from October 10 to November 10）, intensive winter heating period （from Late-December to February） and period of spring windblown dust （April and May）. Most daily concentra- tions of gaseous pollutants, i.e., NO2 （43.8 gg/m3）, CO （0.9 mg/m3）, SO2 （37.9 gg/m3）, and 03 （74.9 gg/m3） were evaluated within level-1 concentration limits of NAAQS standards. However, particulate matter （PM2.5 and PMI0） concentrations （67.3 ~tg/m3and 115.2 ~g/m3, respectively） were significantly higher than their level-1 limits. Severe haze in spring was caused by offsite transported dust and windblown surface soil. Heavy haze periods during fall and winter were mainly formed by intensive emissions of atmospheric pollutants and steady weather conditions （i.e., low wind speed and inversion layer）. The overlay emissions of widespread straw burning and coal combustion for heating were the dominant factors contributing to haze in autumn, while intensive coal burning during the coldest time was the primary component of total emissions. In addition, general emissions including automobile exhaust, road and construction dust, residential and industrial activities, have significantly increased in recent years, making heavy haze a more frequent occurrence. There- fore, both improved technological strategies and optimized pollution management on a regional scale are necessary to minimize emis- sions in specified seasons in Changchun City, as well as comprehensive control measures in Northeast China.

Distribution, Chemical Speciation, and Environmental Risk Assessment of Heavy Metals in Tailings Soils near Dexing Copper Mine, China

To complement information of heavy metals＇ distribution, chemical speciation, activity and environmental risks in agricultural soils surrounding tailings, a total of 16 samples obtained from the 4 # railings site of Dexing copper mine of China were investigated. The total concentrations of heavy metals Zn, Fe, Cu, Pb, Cd, Cr, Hg, As, Mn, Ag, Co, and Ni were determined by inductively coupled plasma-atomic emission spectrometry. Chemical speciations of Cu, Cd, and Zn were investigated with the procedures recommended by Tessier（1979）. Two different assessment approaches （GB 15618- 1995 and risk assessment code, RAC ） were employed to estimate heavy metals＇ environmental risks. Results indicated that heavy metals, especially Cu and Cd were in high levels of accumulation in these samples. Chemical speciation analysis results revealed that Cu was mainly in organic matter bound fraction （ORG） and residual fraction （ RES）, and Cd was predominantly in exchangeable fraction （EXC）, while Zn appeared mainly with the RES fraction. Environmental risk analysis results showed that Cd was in ＂heavy＂ pollution level （ classification m ） in almost all samples, which may exert ＂high＂ or ＂very high＂ environmental risks. Whereas, for Cu, one fourth samples showed ＂heavy＂ pollution level, but were located in ＂low＂ or ＂medium＂ environmental risk ranks. For Zn, many samples were grouped in ＂light＂ pollution level （ classification II ）, but were related to ＂ medium＂ and ＂ high＂ environmental risk ranks. These results indicated heavy pollution and high environmental risk of Cd in soils surrounding the 4# tailings site, which should be paid more attention to. Meanwhile, for Cu and Zn, the contrary results obtained by different environmental risk assessment approaches, may suggest that a more scientific, adequate environmental risk assessment criterion should consider both total content and chemical speciation activity of heavy metals.

Kinetics of Atmospheric Corrosion of Mild Steel in Marine and Rural Environments

In continuation of the extensive studies carried out to update the corrosion map of India, in this study, the degradation of mild steel by air pollutants was studied at 16 different locations from Nagore to Ammanichatram along the east coast of Tamilnadu, India over a period of two years. The weight loss study showed that the mild steel corrosion was more at Nagapattinam site, when compared to Ammanichatram and Maravakadu sites. A linear regression analysis of the experimental data was attempted to predict the mechanism of the corrosion. The composition of the corrosion products formed on the mild steel surfaces was identified by XRD technique. The corrosion rate values obtained are discussed in the light of the weathering parameters, atmospheric pollutants such as salt content ＆ SO2 levels in the atmosphere, corrosion products formed on the mild steel surfaces.

On assessing haze attribution and control measures in China

This paper analyzes the air pollution situation in China,particularly the severe intensifying tendency in central North China.Five major comments on the air pollution issue in China are proposed,emphasizing the scientific understanding on the mechanisms of air pollution formation processes,the interannual variability,the relative roles of climate change and pollutant emissions,the interaction between climate change and atmospheric chemical processes,and the seasonal prediction of air pollution.The viewpoints have significance for air pollution management in China and around the world.

Particulate matter trends and quantification of the spring sand-dust contribution in Hohhot,Inner Mongolia,from 2013 to 2017

On 10 September 2013,the State Council promulgated the Action Plan for the Prevention and Control of Air Pollution(hereinafter referred to as the Action Plan).To study the variations in the air pollutant concentrations in Hohhot during the implementation of the Action Plan and the effects of various measures,the daily concentrations of air pollutants(fine particulate matter(PM_(2.5)),inhalable PM(PM 10),SO_(2),and NO_(2))in Hohhot published by the China Environmental Monitoring Station were obtained to analyze the general meteorological conditions in Inner Mongolia from 2013 to 2017.The variations and causes of the ambient PM concentration in Hohhot were examined,and the quantitative influence of sandstorms on the ambient PM concentration in Hohhot was analyzed by selecting the spring season with frequent sandstorms as an example.The results showed the following.(1)The air quality in Hohhot continuously improved,and compared with those in 2013,the PM_(2.5)and PM 10 concentrations decreased by 24.6%and 48.2%,respectively,in 2017.However,the air pollutant concentrations remained high,with the average PM_(2.5)and PM 10 concentrations exceeding the national secondary standards by 22.9%and 35.7%,respectively.(2)The reductions in the spring PM_(2.5)and PM 10 concentrations were 5.6%and 8.9%,respectively,and the annual decreases in the PM_(2.5)and PM 10 concentrations were 3.6 and 15.1μg m^(−3)yr−1,respectively,from 2013 to 2017.(3)The absolute contribution ranges of dust weather to the concentrations of PM_(2.5),PM 10,and TSP during 2013–17 were 0.6–5.2μg m^(−3),9.0–16.9μg m^(−3),and 14.7–30.0μg m^(−3),respectively,in Hohhot during the spring.

Microbial Function, Enzymatic Activities and Diversity in an Anaerobic-Anoxic-Aerobic Reactor System

Enzymatic activities of beta-gincosidase （ β-GLC ）, （ LAP）, and alkaline phosphatase （ APA）, corresponding to nutrient eliminations, and the microbial community structures were analyzed in an anaerobic-anoxic-aerobic reactor system. Results showed that most activity of β-GLC （64.2 μmoi/（ L · h ）） associated with the largest fraction of small- molecular-weight carbohydrates was found in the aerobic reactor, indicating the existence of coupled hydrolysis-uptake mechanism in the aerobic bacteria. Similar activities of LAP presented in the anoxic and aerobic environments, whose increases accompanied by increments in nitrogen uptake rates greatly accelerated the processes of aerobic nitrification and anoxic denitrification. The highest APA activity displayed in the anaerobic reactor, however, dephosphorization performance was mainly achieved under aerobic condition. Microbial community fingerprints generated by polymerase chain reaction amplification and denaturing gradient gel dectrophoresls （ PCR-DGGE ） revealed that Proteobacterium, Actinobacterium, and Nitrosplra were the predominant classes in the activated sindge and there was no evidence of community variations among each function reactor in the system with biomass recycling.

Inactivation of Giardia by Ozone and Its Disinfect Mechanisms

This study was to investigate the effect of ozone （ O3 ） inactivation on Giardia in water by the fluorescence staining method. In order to elucidate the dominant mechanisms of inactivation, cell surface or inner cell components damage were comparatively examined by scanning dectron microscopy （SEM）. Results suggested that O3 had a stronger effect on inactivating capability. Firstly, when the concentration of O3 was above 2.0 mg/L and the contact time was up to 5 min, it showed a significant inactivating effect. Secondly, the effect of turbidity on inactivation was also found to be significant in synthetic water; when turbidity increased, the inactivating effect decreased. Thirdly, the inactivating rates were improved with a temperature increase from 5 to 25℃, but decreased when the temperature were out of this range. The inactivating capability of O3 was stronger under acidic conditions than alkalic conditions. Lastly, when the concentration of organic matter in the reactive system was increased, probably due to the competition between G/ard/a and organics on O3, the inactivating rate was decreased; in addition, the cellular morphology of Giardia varied with different contact times. At contact time of 30 s, cells were rotundity and sphericity; at 60 s they became folded, underwent emboly, and burst; and at 240 s, the cell membrane of Giardia shrinked and collapsed completely.

The Effect of PM2.5 on Economic Situation of Beijing and Solutions

China＇s environmental problems have become increasingly serious, which have caused great attention of the relevant departments of the state. Through the survey, we found that in most of the cities in our country, the inhalable particulate matter PM10 is one of the main pollutants, especially in the capital of China -- Beijing, which is the arch-criminal cause of the air pollution. According to the quality control report released in Beijing City Environmental Protection Bureau, as can be learned, in recent years, Beijing＇s air quality goes from bad to worse, and in the overall atmospheric pollutants, the PM10 is up to above nine tenths. There are more reports saying that the air pollution levels in Beijing have been not suitable for the human habitation. With the increasing of the air pollution, the term PM2.5 is also more and more familiar to us. The air more intensified the pollution is, the greater the ratio of PM2.5 in PM10 is. In that case, it not only seriously affects the people＇s health, but also brings the huge economic losses. This paper is aimed to analyze the influence of PM2.5 on the economic situation of Beijing, and puts forward the concrete solutions.

Challenges from the New Emission Standards for SO_2 and NO_X

The Emission Standards of Air Pollutants from Thermal Power Plants (GB 13223-2011) prescribe a stricter limitation to air pollutants than ever before. As set in the new emission standard, the limitations of SO2 and NOX for sensitive areas under normal conditions are 50 mg/m3 and 100 mg/m3, respectively. The objective analysis and suggestions are proposed. The recent status and operational experience of desulfurization and denitrification equipment are discussed. From the discussions, thermal power plants face a huge challenge to satisfy the new emission standards. For further reducing of the emission concentrations of SO2 and NOX, three methods were introduced, including: seriously implementing the emission standards, improving treatment equipment, and increasing the efficiencies of desulfurization and denitrification.

A 200-Year Record of Polycyclic Aromatic Hydrocarbons Contamination in an Ombrotrophic Peatland in Great Hinggan Mountain, Northeast China

Peat bogs are regarded as one of the faithful archives of atmospheric polycyclic aromatic hydrocarbons(PAHs) deposition, and a large number of studies on PAHs accumulation in peatlands have been reported in Europe and North America. Comparatively little information is available on peat chronological records of atmospheric PAHs flux in China. We investigated the concentrations and historical accumulation rates of PAHs(AR PAHs) through geochemical analysis of three 210Pb-dated ombrotrophic peat cores from Great Hinggan Mountain, northeast China. Eight USEPA priority PAHs were detected and they are naphthalene(Nap), acenaphthylene(Acl), acenaphthene(Ace), fluorence(Flu), phenanthrene(Phe), anthracene(Ant), fluoranthene(Fla) and pyrene(Pyr), respectively. The average total eight PAHs(tPAHs) concentrations are 135.98- 262.43 μg kg-1 and the average AR tPAHs over the last two centuries are 96.45- 135.98 μg m-2 yr-1. The Ace, Acl and Phe account for 30.93- 54.04%, 25.29- 35.81%, and 9.14- 19.84% of the tPAHs, respectively, and have significant positive correlations with the tPAH. As a result, they are regarded as the iconic compounds of PAHs pollution in this area. A ca.200-yr atmospheric PAHs contamination history was reconstructed from the temporal sequences of bothconcentration and AR tPAHs, suggesting the variation of local environmental pollution. The main sources of the PAHs are identified by two isomer ratios as petrogenic origin including oil extraction and refining process as well as their combustions for industrial development. In addition, the contribution of coal combustion for industrial activities and resident heating could not be ignored. But prior to 1860, the undeveloped industry and most of agricultural activities might mainly account for the low level of PAHs, although it could infer a long-range input of atmospheric PAHs from other industrial areas. Therefore, there is a global implication to study longterm PAHs pollution records and all the results will provide practical significance in formulating policies to achieve sustainable and healthy development.

Thinking About the New Atmospheric Pollutant Emission Standard for Thermal Power Plants

China's new Atmospheric Pollutant Emission Standard for Thermal Power Plants has been made the most stringent atmospheric pollutant emission limit in the world,with the intensified control of nitrogen oxides in the air pollutants emitted by thermal power plants,the tightened limit on the emission of sulfur dioxide,and the widened range of control including mercury and other compounds discharge.The adoption of the new standard will considerably impact the survival and development of power plants,even the whole economy of the nation.While implementing all the policies and measures on emission reduction issued by the State to fulfill political,social,and economic responsibilities,China Huadian Corporation,one of the leading state-owned power generation groups,is actively exploring the green and low-carbon path for the sound and rapid development of the group.

Quantifying Changes of Mobile Source Air Pollution in Metropolitan Areas Using Vehicle Emission Model MOVES

Vehicle emissions are one of the major sources of urban air pollution and are also called mobile source emissions. A large amount of gross vehicle emissions is generated by vehicles commuting between residential homes and the workplace. Homebuyers generally prefer to purchase residential houses that are relatively less expensive, albeit at the cost of relatively longer commuting times. Consumers usually consider additional travel time, fuel consumption, and other personally concerned factors, with less apprehension about the extra air pollution possibly generated. In cities with populations between 15,000 and 1,000,000, an increase of one additional minute of average commuting time is associated with a reduction of 1.9 dollars in housing price per square foot （p-value： 0.038）. To account for the generation of additional air pollution, this paper numerically characterizes factors related to air pollutants caused by additional travel time due to housing prices. Air pollutants such as CO, CO2, NO2, NO, NOx and SO2 as well as fuel consumption were estimated by MOVES （motor vehicle emissions simulator）. The results will be a useful reference to generate recommendations for more efficient reduction of mobile source air pollution in metropolitan areas through joint efforts by government, agencies, the public, and industry from multiple fields including environment protection, land use, housing markets, transportation management, and law enforcement.