Study on Pollution Level and Sources Distribution of Polychlorinated Naphthalenes in City Sewage

Polychlorinated naphthalene （PCNs） have similar structure and toxicity with dioxin class （PCDD/Fs）, it can be detected in the global environmental and biological samples. This paper introduces the main sources of PCNs in the environment and environmental fate, introduced emphasis with the emission characteristics of PCNs in burning and metal smelting process, this article summarized the current PCNs city environmental and biotic pollution level and distribution characteristics, summarized and discussed related research of PCNs pollution level and distribution characteristics near the various environmental media and organisms in the city. Finally, the paper put forward the research progress of PCNs in related research areas and challenges.

Campaigning Against City Pollution

The Atmosphere Wang, a governmental clerk in Beijing, still remembers the good old days when the Beijing sky was clear and blue. "When I was a child, I used to stare at the flowing clouds against the pure, blue sky, and let my imagination roam. But now, I raise my head only to see the sky gray and dull," said Wang, who usually goes to work by bicycle. "When I arrive at the office I have to clean my face with tissues, and they always turn dark." A global inspection on the

Mercury emission and pollution in Chongqing City, China

Investigation showed that mercury emission in Chongqing City, China is about 2.1 t/a, 70% of which came from coal burning.Mercury in many water bodies have been detected, in vegetables and milk had exceeded the food standard value in some places.

Short-term Effects of Air Pollution on Mortality in a Heavily Polluted Chinese City

Since the London fog in 1952, numerous epidemioLogical studies have revealed that both short-term and long-term exposure to air pollutants is associated with the development of diseases[1]. Up to date, the assessment of air quality on health and air quality standard establishment in developing countries were mainly relied on extrapolation based on the results from long-term cohort studies conducted in Europe and North America.

Research on the Low-carbon-high-value Agriculture Technology in the Comprehensive Improvement of Intra-county Environment Pollution——Taking the Development of Cultivation and Breeding Industry in the Ecological Cyclic Agricultural Garden in Shaoshan Irri

The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic perspective,the seriousness of rural water quality,soil and atmospheric pollution in Xiangxiang,Xiangtan and the surrounding areas in Shaoshan irrigated area was revealed.The control measure which was 'four-dimensional pollution in the city and countryside'—— low-carbon-high-value agriculture and the technology innovation was proposed.The low-carbon-high-value technology innovation industrialization demonstration in three parts which included the pre-production,mid-production and post-production deep-processing of cultivation and breeding industry in the ecological cyclic agricultural garden in Shaoshan irrigated area was the driving force.We tried to propel the low-carbon ecological cultivation and breeding industry which included the paddy rice,grass,tree,medicinal herbs and pig,cow,chick,duck,fish.We wanted to relieve the structural unbalance of previous cultivation and breeding industry,'cheap grain hurting the farmers' and the short-leg problem of social-economic-ecological benefit.The results showed that the low-carbon-high-value agricultural system was a poly-generation technology system which promoted the multi-level and grading utilization,saved the energy,reduced the consumption and cleaned the production based on the ecology.

AN AIR POLLUTION PREDICTION TECHNIQUE FOR URBAN DISTRICTS BASED ON MESO-SCALE NUMERICAL MODEL

Taking Shenzhen city as an example, the statistical and physical relationship between the density of pollutants and various atmospheric parameters are analyzed in detail, and a space-partitioned city air pollution potential prediction scheme is established based on it. The scheme considers quantitatively more than ten factors at the surface and planetary boundary layer (PBL), especially the effects of anisotropy of geographical environment, and treats wind direction as an independent impact factor. While the scheme treats the prediction equation respectively for different pollutants according to their differences in dilute properties, it considers as well the possible differences in dilute properties at different districts of the city under the same atmospheric condition, treating predictions respectively for different districts. Finally, the temporally and spatially high resolution predictions for the atmospheric factors are made with a high resolution numerical model, and further the space-partitioned and time-variational city pollution potential predictions are made. The scheme is objective and quantitative, and with clear physical meaning, so it is suitable to use in making high resolution air pollution predictions.

Atmospheric Pollution Control Effect of Key Cities in Inner Mongolia in 2014

APEC conference was held in Beijing during November 3- 12,2014. Hohhot City and Baotou City fall into the peripheral key air pollution control cities in the ＂ Beijing- Tianjin- Hebei＂ region. Inner Mongolia government adopted powerful pollution control measures in the period of the conference. According to pollutant concentration data and meteorological data etc. in the course of the event and the same period of last year,the atmospheric pollution variations and control effect were discussed in this study. The results showed that during October 1- 25,2014,there were 16 days with air pollution in Hohhot City and 15 days with air pollution in Baotou City,respectively increasing by 8% and 34% compared with the same period of 2013,and the concentration of particulate matter was also higher than that of last year. During October 22- 24,2014,Hohhot and Baotou cities were polluted persistently. The variation features of hourly concentration of main pollutants PM（10） and PM2. 5were similar to those in the same period of 2013. That is,the pollutant concentration reached the maximum from 21：00 to 23：00,and the minimum appeared from 15： 00 to 19： 00 in the next day. In the course of the event,the concentration of particulate matter in the two cities stared to reduce greatly on October 26. From October 26 to November 13,there were no days with air pollution in Hohhot City,decreasing by 100% compared with the same period of 2013; there were five days with air pollution in Baotou City,and the numbers of days with slight,moderate and severe pollution reduced by 37%,100% and67% respectively compared with the same period of last year. The persistent air pollution from October 22 to the first 10 days of November was related to unfavorable meteorological conditions,and the meteorological condition in the same period of 2014 was even worse. In the course of the event,the Inner Mongolia Government adopted air pollution control measures around October 25 and began to adopt some powerful pollution control measures on November 1. As a result,air pollution in key cities has been controlled effectively. This event showed that urban atmospheric pollution problem can be resolved,and we should take an optimistic attitude towards this matter.

Climatology of Air Quality in Arctic Cities—Inventory and Assessment

Freely available data of sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) observed in Arctic cities (north of 59.99 N) between 1972 and 2016 were compiled into an air-quality inventory of samples taken for limited periods. For cities with multiple years of data, air-quality climatology was determined in terms of daily means in the annual course. Mean urban air-quality climatology was calculated for regions of similar insolation, emission standards, topography, K&#246ppen-Geiger classification, and city size. Urban concentrations of PM precursors (SO2, NH3, NO2), PM2.5 and PM10 (PM with diameter less than 2.5 and 10 μm) were assessed in the sense of climatology with evidence from current knowledge. Typically, annual SO2 and NO2 means were lower for small than large Arctic cities, but can vary more than an order of magnitude over short distance. Cities seeing seasonal sea-ice had W-shaped mean annual courses of daily O3, while other cities had a spring maximum. Typically, annual means of urban pollutants in North America exceeded those in Scandinavia except for O3, where the opposite was true. Annual mean urban PM2.5 and PM10 concentrations varied from 1.6 to 21.2 μg·m-3 and 2 to 18.2 μg·m-3, respectively. Since PM10 encompasses PM2.5, annual PM10 means must be at least 21.2 μg·m-3. According to rural-to-urban ratios of species, seasonal transport of pollutants from wildfires, shipping, and the Kola Peninsula mining area occurred at some sites in Interior Alaska, western and northern Norway, respectively. Concurrent SO2 and PM or NO2 and PM measurements revealed combustion or traffic as major contributors to urban concentrations. Recommendations for potential future measurements of Arctic urban air quality were given based on the assessments of climatology and inventory.

Comprehensive Management and Protection of Lakes in Kaifeng

Through analysing pollution source and status quo of the main lakes in Kaifeng,such as Dragon Pavilion Lake and Baogong Lake,the conclusion is that Kaifeng＇s lake environment has been in a greater pollution condition. For lake pollution situation,we put forward comprehensive management and protection approaches of lakes,including the relocation of businesses around the lake,plugging the sewage outfall surrounding lakes,dredging and deeply digging to increase the water environment capacity of lake. By dredging the river,the lakes in urban district connect together. Controlling aquaculture scale of lakes,the ecological function of the lake is played. Constructing drainage network around the lake,integration of landscape and lake flood control is formed. Adding new water into lakes,stagnant water becomes flowing water. We sum up the experience of lake management and protection： strengthening protection awareness is the key; lake remediation is the fundamental; attention to ecological protection of the lake is the most important factor in the development of lakes; exploiting a variety of functions of the lakes including landscaping,tourism,recreation,aquaculture,public health is the goal.

Distributive Characteristics of Metallic Nano-particles in China's Urban Water Bodies and their Ecological Risks

Engineering nano-materials & their impact on human health or environmental security constitute a newly emerging R&D hot spot and a key problem now urgently waiting for its solution in supporting the sustainability of China's nano-science and related technology development. At present, water bodies in Chinese cities have been seriously polluted by metallic nano-particles (MNPs) while related monitoring data are found woefully lacking throughout the country. Based on the above understanding, this article gives a round-up explanation on distributive characteristics of MNPs in the river mouths or water bodies of Chinese cities, their ecological hazards as well as our research in this regard, providing some inspiring ideas and data for control over this scourge. In addition, our exploration probes the discharge traits of MNPs themselves and the mechanism underlying its impact on water pollution.

Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China

To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate （TSP） and PMI0 samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were （183 ± 73）, （201± 84） and （190 ±66） μg/m3 respectively, and the average PM10 were （171 ± 82）, （178 ± 65） and （179 ± 55） μg/m3 respectively. The lowest TSP and PM10 concentrations occurred at the background Shaping site of Changsha. The average ratio of p（PM10）/p（TSP） was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8-56.5, 18.1-76.3, 3.9-26.1 and 148.0-460.9 ng/m3, respectively, while in PMI0 samples, were 16.4--42.1, 15.5-67.9, 3.3-22.2 and 127.9-389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest.

Aerosol size distributions during haze episodes in winter in Jinan, China

Number concentrations and distributions of 10-10,000 nm particles in a large city （Jinan） in the North China Plain were measured in winter 2009. The mean number concentrations of nucleation mode （10-20 nm）, Aitken mode （20-100 nm）, and accumulation mode （100-1000 nm） particles, as well as total particles were 925, 6898, 2476, and 10,299cm-3, respectively. Two severe haze episodes, with elevated concentrations caused by pollutants accumulating, were observed. Accumulation mode particle concen- trations were significantly higher during the episodes than on clear days, and nucleation mode particle concentrations were pronouncedly higher on clear days than during the episodes. The peaks of domi- nant number, surface area, and mass size distributions were around 30-50, 200-300, and 200-400 rim, respectively, both during the haze episodes and on clear days, but elevated mass and surface area con- centrations around 500-600 nm were also observed during the haze episodes, suggesting these particles had significant contributions to haze formation. These particles were probably formed through larger droplets in cloud and fog evaporating. Two new particle formation events, probably triggered by strong photochemical processes on clear days and significant traffic emissions during haze episode 2, were found. Significant insights were made into haze formation in a oolluted Chinese urban area.