长春市空气质量污染特征分析与防治对策

为探讨2003－2007年长春市污染新特征,了解大气污染物变化趋势,对市区内客车厂等6个环境空气质量国控点位监测数据进行了归纳计算,并采用API评价方法,得到了PM₁₀、SO₂和NO₂ 3种污染物年均值变化曲线和各种污染类型天数,同时查明了大气污染物的来源。结果表明：2003－2007年间长春市大气污染主要呈现波动略上升的总体特征,据此从气象条件和城市能源消耗等角度分析成因,并提出加深节能减排工作等一系列大气污染防治对策与建议。     

长江口南港的水文泥沙环境及污染物输移

南港河道水域宽广,水体量大,动力条件强,悬沙含量较高且都是细颗粒物质,纳污容量大,具有较强的输运、稀释和自净能力。污水进入南港以后,污染物在河道中迁移转化,主要吸附在泥沙上。在外泄过程中污染物质在南港中往返逗留,循环输移,向底层、滩地、涨潮沟等地迁移,并在河海相接地带富集。     

Implications of EU-Water Framework Directive for the East German Postmining Landscape Lausitz: Coping with a sparse knowledge of the underground

Mining dumps are major sources of pollutants within the mining area of Lausitz, especially sulphate and iron. Their existence in catchment areas comprising groundwater bodies or lakes often imposes negative effects on the water quality. The European Union Water Framework Directive [EU-WFD, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. The European Parliament and Council, L327/1, p. 72] aims to achieve ‘good quality’ status for all water bodies across Europe by 2015. Consequently, predicting the development of ground and lake water quality is necessary and must be based on the geochemical composition of the mining dumps. Therefore, the dumps need to be quantified as pollutant sources.A method to calculate the amount of sulphate in mine dumps is presented. It is based on historic geological and geochemical data characterising the pre-mining situation. Additional information on the dump body, derived from the vertical extension of mining activities and the current Digital Elevation Model (DEM), allows the composition of the dump to be determined. This procedure is demonstrated for the Bärwalde site. An average total sulphur content of 0.62% (5.9 million tonnes) was calculated for the Bärwalde dump. About 40% of it is estimated to be pyrite sulphur. Applying an average pyrite oxidation rate for the whole dump body of 7% led to an additional water-soluble mass of 0.18 million tonnes of sulphate sulphur.Applying this technique to all mine dumps managed by the postmining administration company LMBV, will improve our knowledge of the catchment area for the different lakes of Lausitz and will form an essential basis for reactive transport calculations.     

白洋淀地区土壤——植物系统中污染物含量与变化规律研究

研究长期利用城市污水浇灌的农田土壤--植物系统中污染物的含量及其行为与归宿，不仅对农田生态系统的环境质量控制有重要意义[1],同时，还可以为合理发展污灌，实现污水资源化，促进农业生产的持续发展提供科学依据[2].本文调查了华北白洋淀地区典型污灌农田土壤中污染物含量及其在土壤--植物系统中分布和累积状况。结果表明，污灌区土壤中某些重金属含量有一定的累积趋势。目前，这些重金属对农田作物无明显危害，大部分累积在根部。加强科学管理和污灌指导，利用农田作为土地处理系统来消纳污水中耗氧有机物，是本地区近期可行的污水资源化途径之一。     

填海造地对胶洲湾污染物输运影响的数值研究

以胶洲湾为例，采用分步杂交法，在已建潮流场的基础上，建立胶洲湾海域二维变边界对流－扩散数值模拟，选COD为有机污染的指标因子，并视为保守元素，对不同的填海方案，造成胶州湾内COD浓度场的改变及污染物通量的变化，进行计算分析，并给出对污染物输运影响数值研究的初步结论。     

太原地区灰霾天气特征及影响因子分析

利用2008~2012年太原常规地面气象观测资料、高空探测资料和大气污染物观测资料,对主要天气形势、典型气象要素以及空气污染状况下灰霾天气特征及形成机制进行了综合分析。结果表明:1)太原地区灰霾出现频率存在明显的季节变化,冬半年灰霾出现天数占全年的65.7%;一天中08:00(北京时间,下同)至13:00发生灰霾的频率较高。2)霾日静风频率较高,主导风向为偏东南风;重度灰霾天气出现时相对湿度较高。3)霾日的大气稳定度主要表现为稳定类;霾日平均混合层高度比非霾日低约100 m;08:00逆温出现次数高于20:00,霾时平均逆温强度和厚度高于非霾时。4)高压类型天气形势对灰霾的产生有重要影响,低压天气形势下较少出现灰霾天气。5)可吸入颗粒物、SO2和NO2浓度在非霾日比霾日分别下降32.6%、48.6%、21.7%;随着灰霾等级的增加,SO2和可吸入颗粒物的浓度有显著的增加。6)灰霾天气下到达地面的太阳辐射强度明显减弱,日照时数明显减少。     

On the Impact of Trees on Dispersion Processes of Traffic Emissions in Street Canyons

Wind-tunnel studies of dispersion processes of traffic exhaust in urban street canyons with tree planting were performed and tracer gas concentrations using electron capture detection (ECD) and flow fields using laser Doppler velocimetry (LDV) were measured. It was found that tree planting reduces the air exchange between street canyons and the ambience. In comparison to treeless street canyons, higher overall pollutant concentrations and lower flow velocities were measured. In particular, for perpendicular approaching wind, markedly higher concentrations at the leeward canyon wall and slightly lower concentrations at the windward canyon wall were observed. Furthermore, a new approach is suggested to model porous vegetative structures such as tree crowns for small-scale wind-tunnel applications. The approach is based on creating different model tree crown porosities by incorporating a certain amount of wadding material into a specified volume. A significant influence of the crown porosity on pollutant concentrations was found for high degrees of porosity, however, when it falls below a certain threshold, no further changes in pollutant concentrations were observed.     

非开挖导向强度分析及其在电力铺管设计中的应用

全面分析了非开挖铺管导向钻进轨迹设计的主要决定因素;合理地剖析了钻遇地层的性质及其它施工条件对导向强度的影响;提出导向强度的计算方法,更科学、准确地设计出导向孔轨迹,并应用到实际电力管道铺设导向孔三维轨迹设计中。     

Critical pollution levels in Umguza River,Zimbabwe

In most countries worldwide regulatory bodies set effluent discharge limits into rivers and other natural water bodies. These limits specify the maximum permissible concentration of defined pollutants that may be discharged into the water body. This limit is conceptually based on the self-purification (assimilative) capacity of the receiving water. However, this self-purification constant is itself a function of the water's pollutant loading. Umguza River situated south west of Zimbabwe, is fed by tributaries that drain an urban catchment and as such is prone to pollution due to human activities in the catchment. This study investigated the levels of pollution in Umguza River that would affect its self-purification capacity. This was achieved by characterising the spatial distribution of a selected range of water quality parameters as well as determining the self-purification capacity of a stretch of the river. Critical pollutant concentrations were determined for some of the parameters that showed high values along the stretch. The selected parameters of interest were dissolved oxygen, suspended solids, phosphates, nitrates, COD, turbidity, ammonia, pH, alkalinity and temperature. The study was carried out from January 2014 to April 2014. The self-purification capacity was determined using a formula that compares the mass flux of a pollutant upstream and downstream of the selected stretch of the river. Statistical analysis was used to establish relationships between the pollutants and the self-purification capacity of the river. The study found that the levels of ammonia and phosphates were very high compared to the regulated limits (2 mg/l vs 0.5 mg/l; and 8 mg/l vs 0.5 mg/l respectively). It was also found that the self-purification capacity varied significantly across pollutants. It was therefore concluded that a critical pollutant concentration exists above which the river completely loses its natural ability to assimilate and decrease its pollutant load over time. It was also concluded that the self-purification capacity depends on the pollutant of concern in the river. It is recommended that the self-purification capacity of a river be determined before regulatory bodies set effluent discharge limits. It is also recommended that the water quality of water bodies draining pollution prone catchments be monitored regularly, besides just monitoring the discharge points.