新疆农业碳减排管理经验初探

研究了美国国际集团(AIG)注资新疆昌吉玛纳斯等3县开展温室气体减排项目的推进过程.这是在中国成功开展的第一例农业温室气体自愿减排项目,该项目共减排温室气体21×104t CO2当量.主要通过农户沼气推广、沙漠防沙林种植、农业滴灌灌溉等项目,达到温室气体减排、节约能源、防沙造林、改善当地的生态环境、增加农民收入等目的....     

浅谈新疆“十二五”畜禽养殖业主要污染物的减排

结合主要污染物"十二五"总量控制规划编制工作经验,对新疆畜禽养殖业主要污染物的减排潜力及途径进行分析,宏观测算出新疆畜禽养殖业"十二五"期间的减排潜力,并提出新疆畜禽养殖业的减排途径及方法,为新疆主要污染物"十二五"减排工作提供合理化建议。     

中山市一次臭氧重污染过程污染来源和减排效果模拟分析

利用WRF-CMAQ模式和中山市空气质量预报预警业务系统中的NAQPMS模式,对中山市2022年9月一次臭氧(O₃)重污染过程进行了污染过程分析、来源解析和减排评估分析。WRF-CMAQ模式能较好地模拟出该时段的气象条件、二氧化氮及O₃浓度的变化过程。该次O₃污染过程主要是由台风外围下沉气流叠加大陆高压等不利气象条件引起的。本地排放及区域输送对中山市O₃浓度的平均贡献率分别为20.5%和79.5%,区域输送占主导。对中山市O₃浓度贡献最大的两个来源分别是交通源和溶剂使用源,平均贡献率分别为39.6%和35.6%。工业源的贡献也不可忽略,平均贡献率为9.9%。单独针对中山市进行减排,无法消除本次重度污染天气,表明单个城市减排难以抵御区域性大范围污染过程,需加强区域联动。模拟结果显示,对中山、广州、东莞、佛山、江门和深圳等珠三角重点城市进行联合减排,减排力度越大则空气质量改善越明显。当减排力度达到100%时,可消除中度及以上污染天气,但依然存在轻度污染天气,表明大幅度减排可以显著降低O₃浓度峰值和减少O₃污染天数,但仍难以完全抵御极端不利气象条件的影响。     

我国污水资源化战略探讨

当前我国用水面临水资源短缺和水环境恶化的双重考验,污水资源化是解决水资源短缺和水环境恶化的有效途径。本文根据对我国污水资源化实施状况的调查分析,探讨了我国开展污水资源化的若干战略因素。     

长江下游典型滨海地区农业土壤重金属污染特征

为揭示长江下游滨海地区农业土壤重金属污染状况,以滨江临海的南通市为例,网格化布点,采集表层农业土壤样品共计334个,对其重金属Cu、Pb、Cr、As、Hg含量进行了测定分析.结果表明,研究区域表层农业土壤中各重金属含量均已超过其背景值,且以Pb污染最为严重;区域性差异较大,以滨海的如东、海门、启东污染最为严重,且以海门、启东As含量最高;各重金属间相关性不显著,来源途径不止一种.从而提出南通市农业土壤重金属污染的防治应立足于防重于治的方针,着重滨海地区,以Pb、As污染源为主,并对污染土壤进行修复.     

Ambient Aerosol and its Carbon Content in Gainesville, a Mid-Scale City in Florida

Ambient aerosols were collected during 2000–2001 in Gainesville, Florida, using a micro-orifice uniform deposit impactor (MOUDI) to study mass size distribution and carbon composition. A bimodal mass distribution was found in every sample with major peaks for aerosols ranging from 0.32 to 0.56 μm, and 3.2 to 5.6 μm in diameter. The two distributions represent the fine mode (<2.5 μm) and the coarse mode (>2.5 μm) of particle size. Averaged over all sites and seasons, coarse particles consisted of 15% carbon while fine particles consisted of 22% carbon. Considerable variation was noted between winter and summer seasons. Smoke from fireplaces in winter appeared to be an important factor for the carbon, especially the elemental carbon contribution. In summer, organic carbon was more abundant. The maximum secondary organic carbon was also found in this season (7.0 μg m⁻³), and the concentration is between those observed in urban areas (15–20 μg m⁻³) and in rural areas (4–5 μg m⁻³). However, unlike in large cities where photochemical activity of anthropogenic emissions are determinants of carbon composition, biogenic sources were likely the key factor in Gainesville. Other critical factors that affect the distribution, shape and concentration were precipitation, brushfire and wind.     

低碳经济背景下克拉玛依市的发展现状分析

克拉玛依是一座典型的资源型城市,正处于工业化、城市化快速发展的阶段,能源消费和CO2排放持续增长将成为克拉玛依经济发展的硬约束。本文以2002—2013年克拉玛依市统计年鉴中的产业结构、人口、能源消费和经济数据为基础,分析了克拉玛依市的产业结构、能源消费、CO2排放情况,提出了发展低碳城市的思考。     

Natural and Anthropogenic Factors Controlling the Dissolved Organic Carbon Concentrations and Fluxes in a Large Tropical River, India

Carbon studies in tropical rivers have gained significance since it was realized that a significant chunk of anthropogenic CO₂ emitted into the atmosphere returns to the biosphere, that is eventually transported by the river and locked up in coastal sediments for a few thousand years. Carbon studies are also significant because dissolved organic carbon (DOC) is known to complex the toxic trace metals in the river and carry them in the dissolved form. For the first time, this work has made an attempt to study the variations in DOC concentrations in space and time for a period of 19 months, and estimate their fluxes in the largest peninsular Indian river, the Godavari at Rajahmundry. Anthropogenic influence on DOC concentrations possibly from the number of bathing ghats along the banks and domestic sewage discharge into the river are evident during the pre-monsoon of 2004 and 2005. The rise in DOC concentrations at the onset of monsoon could be due to the contributions from flood plains and soils from the river catchment. Spatial variations highlighted that the DOC concentrations in the river are affected more by the anthropogenic discharges in the downstream than in the upstream. The discharge weighted DOC concentrations in the Godavari river is 3–12 times lower than Ganga-Brahmaputra, Indus and major Chinese rivers. The total carbon fluxes from the Godavari into the Bay of Bengal is insignificant (0.5%) compared to the total carbon discharges by major rivers of the world into oceans.     

Roadside Concentration of Gaseous and Particulate Matter Pollutants and Risk Assessment in Dar-Es-Salaam, Tanzania

This study used manual air sampling method to assess the contribution of road traffic to air pollution level in Dar-es-Salaam City, Tanzania. Samples were collected from 11 different sites. Parameters measured were: sulphur dioxide using pararosaniline method, nitrogen dioxide using saltzman method, particulate matter and particulate lead using filtration method and atomic absorption spectrometric method, respectively. Results showed that hourly average sulphur dioxide concentration range from 127 to 1385 g/m³. The measured values of sulphur dioxide were above the recommended WHO guidelines with an hourly objective value of 350 g/m³ at 87% of the sampling sites. The hourly average nitrogen dioxide concentration ranged from 18 to 53 g/m³. The maximum hourly nitrogen dioxide concentration at 53 g/m³ was below the WHO guideline value of 200 g/m³. The hourly average suspended particulate matter (SPM) ranged from 98 to 1161 g/m³, exceeding the recommended value of 230 g/m³ by WHO at 87% of the sampling sites. The hourly average lead concentration was found to range from 0.60 to 25.6 g/m³, exceeding again the WHO guideline value of 1.5 g/m³at 83% of the sampling sites. Results predicted by Gaussian model when compared with the measured values were found to have a correlation coefficient of 0.8, signifying a good correlation. The risk assessment was undertaken considering the people who spend a significant portion of their time near the roads, such as the Uhuru primary school pupils and the adult population who reside by the roadside. The unit risk realised was 18.2 × 10^–6 for adult population and 2.2 × 10^–6 for pupils, both scenarios showing risk higher than the United Sates of America Environmental Protection Agency (USEPA) acceptable limit of 1× 10^–6. Considering the magnitude of the problem at hand, this study recommends an introduction of mandatory emission tests of SPM, lead and sulphur dioxide (SO₂). The study further recommends the introduction of continuous and/or regular air quality monitoring and the use non-leaded petrol in Tanzania.     

Effects of Traffic Management and Transport Mode on the Exposure of Schoolchildren to Carbon Monoxide

The exposure to CO of schoolchildren was assessed in the town of Northampton, UK, both by direct measurement and by GIS-based activity modelling. Personal measurement of CO showed that exposures when travelling by car were significantly greater than those when walking, although journey times by car were shorter. However, journey exposures had little effect on maximum 8h mean CO exposures. CO concentration fields in the study area were modelled from current traffic flows, and those expected under different traffic management scenarios. These fields were then used, in combination with children's home and school location, and their activity profiles, to simulate frequency distributions of exposure for different transport modes and traffic management scenarios. The results show a large variability in the effect of traffic management interventions, depending on the child's home and school location.     

Spatial Variability of Soil Organic Carbon in Relation to Environmental Factors of a Typical Small Watershed in the Black Soil Region, Northeast China

A total of 292 soil samples were taken from surface soil (0–20 cm) of a typical small watershed–Tongshuang in the black soil region of Heilongjiang province, northeast China in June 2005 for examining the concentration of soil organic carbon (SOC). Spatial variability of SOC in relation to topography and land use was evaluated using classical statistics, geostatistics and geographic information system (GIS) analyses. The objective of this study was to provide a scientific basis for land management targeting at improving soil quality in this region. Classical statistical analysis results indicated that the variability of SOC was moderate (C _V = 0.30). Slope position and land use types were discriminating factors for its spatial variability. Geostatistics analyses showed that SOC had a strong spatial autocorrelation, which was mainly induced by structural factors. Mean concentration of SOC in surface soil was 2.27% in this watershed, which was a very low level in the northern black soil region of northeast China. In this small watershed, present soil and water conservation measures played an important role in controlling soil loss. But SOC's restoration was unsatisfactory. Nearly three-quarters of the area had worrisome productivity. How to improve SOC concentration targeting at soil fertility is a pressing need in the future.     

Air Quality in Norwich, UK Multi-Scale Modelling to Assess the Significance of City, County and Regional Pollution Sources

Norwich is the eastern most city in the United Kingdom. Despite a population of only 100,000 and very little local industry, studies have shown that the city experiences levels of nitrogen dioxide, ozone, particulates and sulphur dioxide exceeding the UK Air Quality Standards. Because of Norwich's situation within a large, predominantly rural area a large non-resident workforce is one factor that contributes to large, often very congested traffic flows. The city's location close to the European mainland also exposes it to polluted airmasses transported from the continent, especially in the case of particulates and ozone. In order to assess the relative contributions of local and regional sources, data from rural and urban monitoring sites are to be used in conjunction with ADMS-Urban and the UK Meteorological Office's NAME model.     

Comparison of EC and BC and evaluation of dust aerosol contribution to light absorption in Xi'an, China

The concentrations of EC, BC and dust aerosols were determined for atmospheric samples collected from an observation station in Xi'an, China. The results show that the averaged correlation coefficient between EC and BC was founded to be 0.72 with 0.81 (n = 49) in autumn, 0.70 (n = 112) in winter and 0.69 (n = 57) in spring, respectively. Absorption coefficients of dust aerosol were estimated to be 2.7 m² g⁻¹ in autumn and 4.4 m² g⁻¹ in winter. The comparison of absorption coefficients of dust aerosol with those of BC implies that BC is the principal light-absorbing aerosol over Xi'an atmosphere. By combining thermal analysis of elemental carbon and dust contents in the aerosol samples, however, the fraction of dust absorption to total light absorption is estimated to be 19% in autumn and 31% in winter, respectively.     

Concentrations of PM2.5-associated OC, EC, and PCDD/Fs measured during the 2003 wildfire season in Missoula, Montana

Throughout August and September, 2003, wildfires burned in close proximity to Missoula, Montana, with smoke emanating from the fires impacting the valley for much of the summer. This presented the perfect opportunity to measure the levels of polychlorinated dibenzodioxins and dibenzofurans (PCDD/F) comprising ambient forest fire smoke particles impacting the Missoula Valley. An air sampler at the Montana Department of Environmental Quality's (DEQ) compliance site in Missoula measured hourly averages of PM₁₀ throughout the fire season. Three collocated PM_2.5 cyclones collected 24-h smoke samples using quartz filters and Polyurethane Foam (PUF) sorbent cartridges. From the quartz filters, concentrations of Organic and Elemental Carbon (OC/EC) were measured, while PCDD/F were measured from one set of a filter (particle phase) and PUF (vapor phase) aggregate of samples in an attempt to also investigate the different phases of PCDD/F in forest fire smoke impaired communities.Hourly PM₁₀ concentrations peaked at 302.9 μg m⁻³ on August 15. The highest OC concentration (115.6 μg m⁻³) was measured between August 21–22, and the highest EC concentration of 10.5 μg m⁻³ was measured August 20–21. Measurable concentrations of PM_2.5 associated PCDD/Fs were not detected from a representative aggregate sample, with the exception of small amounts of 1,2,3,4,6,7,8-heptachlorodibenzodioxin and octachlorodibenzodioxin. PM_2.5 samples collected during the smoke events were composed of approximately 65% OC. However, the OC fraction of the particles collected in the smoke impaired Missoula valley was not composed of significant amounts of PCDD/F.     

Study of Meteorological Aspects and Urban Concentration of SO2 in Atmospheric Environment of La Plata, Argentina

This article presents and discusses SO₂ (ppbv) concentration measurements combined with meteorological data (mainly wind speed and direction) for a five-year campaign (1996 to 2000), in a site near an oil refinery plant close to the city of La Plata and surroundings (aprox. 740.000 inh.), considered one of the six most affected cities by air pollution in the country. Since there is no monitoring network in the area, the obtained results should be considered as medium term accumulated data that enables to determine trends by analyzing together gas concentrations and meteorological parameters. Preliminary characterization of the behaviour of the predominant winds of the region in relation with potential atmospheric gas pollutants from seasonal wind roses is possible to carry out from the data. These results are complemented with monthly averaged SO₂ measurements. In particular, for year 2000, pollutant roses were determined which enable predictions about contamination emission sources. As a general result we can state that there is a clear increase in annual SO₂ concentration and that the selected site should be considered as a key site for future survey monitoring network deployment. Annual SO₂ average concentration and prevailing seasonal winds determined in this work, together with the potential health impact of SO₂ reveals the need for a comprehensive and systematic study involving particulate matter an other basic pollutant gases.