垃圾填埋场植被恢复及其环境影响因子的研究

对中山市一个关闭了5a左右的垃圾卫生填埋场进行植被恢复、土壤、填埋气和植物自然定居与植被恢复等方面的调查研究。结果表明：垃圾填埋场的土壤偏碱性，场内土壤的盐分、含水量、有机质和重金属等含量远远高于场外的对照土壤。填埋场的植被自然恢复得很好，总盖度达到98％，以草本植物为主，灌木为辅，另外还有少量的藤本植物和乔本存在。本次调查共记录高等植物74种，隶属63属30科。优势种为狗牙根，亚优势种包括苦楝、胜红蓟、蟛蜞菊、加拿大飞蓬、小牵牛、鸭跖草、少花龙葵、鸡矢藤、红斑一品红、牛筋草、类芦和田菁等12种植物。其中类芦、加拿大飞蓬和胜红蓟是本垃圾填埋场植被恢复先锋植物。场内的填埋气含量显著地高于对照样方，但与其它垃圾填埋场相比，其填埋气的含量较低，因此填埋气对植被恢复的限制作用也相对较小。影响本填埋场植被恢复的环境因子主要是土壤的营养成分、重金属和填埋气。最后，提出了对垃圾填埋场进行植被恢复时应采取的关键措施。图1表5参19。     

城市垃圾填埋场建设环境影响评价支持系统设计

我国卫生填埋场产生的环境污染愈来愈突出，引起人们普遍关注。填埋场建设之前做好环境影响评价，对于垃圾填埋场选址，建设，管理，以及有效防止填埋场对环境污染显得非常重要。填埋场环境影响评价考虑因素很多，需要应用较多的数学模型及方法。鉴于此，在对其环境影响系统分析基础上本文建立了一个评价内容全面，实用性强，规范快速的填埋环境影响评价系统EIASL(Environmental Impact Assessment System of Landfill)。     

Application of CFD modelling to air quality in Kuwait City

High-resolution computational fluid dynamics (CFD) simulations have been performed to assess the dispersion of air pollutants (CO₂) emanating from traffic in a busy street and in the vicinity of a complex configuration of buildings located in Salmiya, Kuwait City. New buildings are planned for this area, and the work here includes predictions for the dispersion of pollutants after the buildings’ completion. The CFD simulations are based on calculated CO₂ concentration levels for traffic counts taken on location in Salmiya with the existing configuration of buildings. As the computer code used in this work has been evaluated previously, it will be applied here to predict with confidence any potential air pollution problem areas on the addition of the new buildings. It was found for very light wind, that the proposed new buildings help reduce pollution in the vicinity of residential buildings within the configuration of buildings, but as the wind becomes moderate to strong, there was a tendency for the pollutant to get trapped in the residential area. Results are given for both exceptionally high ambient temperatures and very light wind, which are not often reported in studies found in the literature.     

封闭垃圾填埋场通过地表向大气释放汞的测定

利用动力学通量箱及自动测汞仪联用技术,于2004年3月中旬对贵阳市的一座封闭生活垃圾填埋场汞通过地表向大气释放的过程进行了研究。3个采样点的汞释放通量日均值分别为559.1、88.2、53.6ng·m-2·h-1,汞释放通量强度与表层基质中的汞含量密切相关,该测定值高于世界背景地区通量的1~2个数量级,说明封闭垃圾填埋场也是大气汞的潜在来源。汞释放通量呈现明显的昼夜变化规律,白天较高并在午间前后达到最大,而夜间降至最低。气相因子中光照强度与汞的释放过程相关性最高,其次分别是气温、相对湿度、地温和风速。氧化态汞的光致还原作用是可能垃圾填埋场Hg0生成的主要途径,降雨初期能促进地表汞的释放。     

生活垃圾填埋场地下水污染风险分级方法研究

在综合分析国内外不同行业、不同领域风险分级方法的基础上,初步建立了一种生活垃圾填埋场地下水污染风险分级方法。该方法利用由美国环保局（USEPA）开发的多介质、多路径、多受体风险评价模型（3MRA）中用于描述污染物在地下水迁移的EPACMTP模型和风险评估模型计算生活垃圾填埋场地下水污染风险指数I,利用地下水含水层脆弱性模型（DRASTIC模型）计算地下水含水层脆弱性指数DRASTIC。并以I和DRASTIC为风险分级指标,以MATLAB聚类分析为方法,对生活垃圾填埋场地下水污染风险进行分级。以北京市22个生活垃圾填埋场为例,利用建立的风险分级方法,可将这22个填埋场地下水污染风险从高到低分为4级,并且大部分填埋场属于风险级别较低的3、4级。表明该风险分级方法可行、有效,在一定程度上可以为生活垃圾填埋场地下水污染的风险管理提供依据。     

硝化渗滤液回灌对填埋垃圾反硝化、产甲烷及稳定化的影响

垃圾填埋场是重要的甲烷释放源,其有效管理是减缓温室效应的重要环节.通过硝化渗滤液回灌模拟垃圾填埋柱,研究硝化渗滤液在新鲜垃圾和老龄垃圾填埋柱中的脱氮及对垃圾稳定化和产甲烷的影响.结果表明,回灌的硝化渗滤液在不同填埋龄垃圾柱中,均可实现总氧化态氮(Total oxidation nitroge,TON)完全还原.当回灌TON负荷分别达到14.19 g t-1(TS)d-1和10.45 g t-1(TS)d-1时,新、老垃圾柱中甲烷产生开始受到抑制.实验后期,回灌TON负荷增至38.78 g t-1(TS)d-1和30.62 g t-1(TS)d-1时,新、老垃圾填埋柱产甲烷相对抑制率分别达54.10%和95.77%.同时,回灌反硝化对新、老垃圾柱中垃圾降解贡献率(Rd)分别达85%和93%,能有效促进垃圾稳定.     

Aeolian erosion of storage piles yards: contribution of the surrounding areas

Dust emissions from stockpiles surfaces are often estimated applying mathematical models such as the widely used model proposed by the USEPA. It employs specific emission factors, which are based on the fluid flow patterns over the near surface. But, some of the emitted dust particles settle downstream the pile and can usually be re-emitted which creates a secondary source. The emission from the ground surface around a pile is actually not accounted for by the USEPA model but the method, based on the wind exposure and a reconstruction from different sources defined by the same wind exposure, is relevant. This work aims to quantify the contribution of dust re-emission from the areas surrounding the piles in the total emission of an open storage yard. Three angles of incidence of the incoming wind flow are investigated ( $30^{\circ }, 60^{\circ }$ and $90^{\circ }$ ). Results of friction velocity from numerical modelling of fluid dynamics were used in the USEPA model to determine dust emission. It was found that as the wind velocity increases, the contribution of particles re-emission from the ground area around the pile in the total emission also increases. The dust emission from the pile surface is higher for piles oriented $30^{\circ }$ to the wind direction. On the other hand, considering the ground area around the pile, the $60^{\circ }$ configuration is responsible for higher emission rates (up to 67 %). The global emissions assumed a minimum value for the piles oriented perpendicular to the wind direction for all wind velocity investigated.     

Indicating landfill stabilization state by using leachate property from Laogang Refuse Landfill

Variation and evolution process of leachate can be applied as a reference for landfill stabilization phase. In this work, leachates with different ages were collected from Laogang Refuse Landfill, and characterized with 14 key parameters. Simultaneously, principal component analysis （PCA） was applied to develop a synthetic parameter-F based on these 14 parameters, and a logarithm equation was simulated for the landfill stabilization process finally. It was predicted that leachates would meet Class I and Class II in standard for pollution control on the landfill site of municipal solid waste （GB 16889-1997） after 32 years and 22 years disposal under the natural attenuation in the humid and warm southern areas of China, respectively. The predication of landfill state would be more accurate and useful according to the synthetic parameter F of leachate from a working landfill.     

Effect of the topography of an industrial site on dust emissions from open storage yards

The erosion, transport and subsequent deposition of particles by wind has been identified as an important environmental problem worldwide. Investigations assessing fugitive dust emissions represent a relevant subject for various applications such as prevention of desert expansion, farmland erosion, quantification of dust emissions due to wind erosion from mining zones or open storage yards of granular materials. The present study, within this latter framework, aims to improve the methods of quantification of fugitive emissions from granular materials stockpiles on industrial sites. The methodology mostly used by the industrial operators to quantify dust emissions from their plants is based on the wind flow analysis and application of emission factors into such pattern. In this paper, three-dimensional numerical simulations were done to simulate wind flow over a real configuration of a power plant to highlight the influence of the surroundings buildings on the real exposure of the granular materials stockpiles. This study emphasizes the necessity to take into consideration the presence of surrounding buildings for the calculation of the particle emissions rate on stockpiles in order to obtain a more accurate and relevant evaluation of fugitive dust emissions from open storage systems on industrial sites.     

Evaluation and remediation of organics,nutrients and heavy metals in landfill leachate – a case study in Beijing

Leachate pollution in landfill sites is a major source of environmental concern. This study evaluates organics, nutrients and heavy metals in a landfill site in Beijing, and introduces a method combining coagulation–flocculation with filtration for the advanced treatment of leachate. The results confirm that COD_Cr, TN, NH₄⁺ ? N, TP, Mn and As in leachate treated by an anaeobic–oxic biological method are unable to meet discharge or surface water quality standards. When treated with coagulation–flocculation combined with filtration under optimal conditions (cationic polyacrylamide dosage of 8.0 mg/L; polyaluminium chloride dosage of 350 mg/L; 0.4–0.6 mm ceramsite media in the filtration process), the residual NH₄⁺? N, TN, Mn and As in the leachate meet the maximum allowed values for landfill leachate discharge or surface water quality standards in China; the exceptions are chemical oxygen demand and total phosphorus. Leachate treatment processes could be further strengthened or improved.     

Dust emission calculations in open storage piles protected by means of barriers, CFD and experimental tests

The importance of open mineral storage piles in bulk solids port terminals have increased considerably in recent years in Europe and USA (in Spain, great extensions of transoceanic ports are being made) to address the increasing demand of raw material importation due to local mining operation closure. These storage piles are affected by the climatologically processes and the dust emission to the atmosphere, causing repercussions to health and environmental, which is intimately related to the air velocity, according to USEPA studies, maximum ratio of dust emission emitted from CFD and software Ansys CFX 10.0 is determined. In addition, an emission variability study based on the pile distance of different height solid barriers is developed, reducing the emission to 66%. The studies have been contrasted by published investigations and industrial measurement.     

垃圾填埋场新型覆盖层材料厚度对甲烷氧化行为的影响

甲烷是一种长期存在于大气中的重要温室气体,它对温室效应的贡献率是二氧化碳的21倍,生活垃圾填埋场是仅次于水稻田的第二大甲烷人为排放源,减少垃圾填埋场的甲烷气体排放对缓解全球变暖压力具有重要意义.在实验室条件下模拟垃圾填埋场甲烷排放情况,将堆肥+陶粒混合物(体积比1:1)这一新型覆盖层材料按6个厚度(30、40、50、60、70、80 cm)装入有机玻璃柱中研究甲烷氧化与覆盖层深度的关系.研究结果表明:试验94 d甲烷氧化率开始下降,到实验结束前6个柱体中甲烷氧化率相似,维持在24.6%～34.8%之间;甲烷氧化速率由于甲烷通入量不断加大呈现先增加后减小的趋势,最低值为2.45 mol·m~(-2)·d~(-1),最高值为17.82 mol·m~(-2)·d~(-1);在试验第119～121d对各个柱体不同深度的气体成分进行分析.发现甲烷氧化的范围主要集中在基质0cm～30cm深处.     

Phytoremediation of landfill leachate using Pennisetum clandestinum

Landfills are still the most widely used solid waste disposal method used across the world. Leachate generated from landfill areas exerts environmental risks mostly on surface and groundwater, with its high pollutant content, most notably metals, which cause an unbearable lower water quality. During dumping or after the capacity of the landfill has been reached, a decontamination and remediation program should be taken for the area. This study was conducted to assess the capacity and efficiency of Pennisetum clandestinum, a prostrate perennial plant, to accumulate chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), zinc (Zn) and lead (Pb). Leachate, taken from the Sofulu Landfill Site, was given to Pennisetum clandestinum for 180 days, in 3 dilution sets as 1/1, 1/2 and 1/4, in batch configuration. An additional control set was also installed for comparison. Results showed that, even though the metal content of soil had risen, plants accumulated 2 to 8.5 times higher concentrations than the control set. It is important to see, the plant showed almost no stress symptoms even if the set was fed by pure leachate. Pennisetum clandestinum was observed to accumulate metals mostly in the upper bodies, excluding Fe and Cu. 76% of accumulated Cr, 85% of Ni, 66% of Zn and 100% of Pb was observed to accumulate in above-ground parts, where only 20% of Cu and 4% of Fe was accumulated. Due to the high pollution tolerance of Pennisetum clandestinum, makes this plant suitable for decontamination and remediation of landfill sites.     

北京PM2.5化学物种的质量平衡特征

以北京2个采样点连续采集的样品对PM2.5中的元素、水溶性离子和含碳组分进行分析．车公庄和清华园PM2.5中有机物的含量分别为27．8％和30．9％,是含量最丰富的物种,其次是二次无机粒子、土壤尘、元素碳和微量元素．PM2.5中约有24％的质量未能鉴别成分,相关性分析表明,含碳物种的估算所引起的偏差可能是主要的原因．采暖期重污染周和春季沙尘周PM2.5的化学物种构成悬殊,反映了季节性变化的源排放和特殊气象条件的综合作用．     

Source apportionment of polycyclic aromatic hydrocarbons in Lake Baikal water and adjacent air layer

The composition of polycyclic aromatic hydrocarbons (PAHs) in Lake Baikal water and adjacent air layer and PAH emission composition profiles of possible sources were investigated. Analysis of emission composition data showed that the source profiles could not be grouped by fuel type or pyrogenic/petrogenic origin. Because of the similarity of source PAH profiles, the drawing of 3D mixing diagrams was the only way to check whether some of the potential PAH sources were the true sources. The mixing diagrams showed that the sources of air pollution were paper mills and wood burning and that the sources of water pollution were coal-fired and oil-fired boilers. The common source for both air and water was only oil and petroleum products. To determine the locations of PAH sources, their contributions to air and water pollution were calculated and mapped. Based on the results, air and water were polluted from both local and regional sources. The location of the zone influenced by a particular source was conditioned by physical properties of source emission, direction of air/water flows that transfer PAHs and temperature differences between mixing air/water flows.     

Effects of greenbelt plant configuration on atmospheric PM2.5 in Beijing

High atmospheric PM2.5 concentrations are a major problem associated with air pollution in Beijing due to their frequent occurrence and harmful effects. The construction of greenbelts beginning in 2000 has altered the surface structure of the area between 4th ring road and 6th ring road; wind speed, which strongly influences the atmospheric PM2.5 content, has decreased simultaneously during this period. Here, we estimated the effects of different plant configurations on wind speed and dust retention in Beijing. We recommend configuring rough bushy shrub-grass in the northwest, west, and north; grass and rough bushy shrub-grass in the north, east, and southeast; and rough bushy shrub-grass and arbor-shrub-grass in the southwest and northeast. As vegetation types and planting methods influence the ability of shrub-grass and arbor-shrub-grass to block wind and dust, we recommend increasing planting density and introducing plants with hairy leaves and exuberant foliage.     

Accounting for the Mesoscale Effects on the Air Pollution in Some Cases of Large Sulfur Pollution in Bulgaria or Northern Greece

The objective of the present work is to demonstrate the influence of the meso-scale dynamic phenomena on the larger scale air pollution characteristics. A limited set of episodes with very large sulphur pollution in Bulgaria or Northern Greece is chosen for the study. A 3D quasi-hydrostatic model of the meso-scale dynamics, based on the Businesque approximation (the formulation of Guthman) is used for the purpose. Some numerical experiments for the Balkan Peninsula are carried out under different background (synoptic) conditions. The simulated flow systems outline the main topography effects, typical for the region, such as slope winds, channelling of the air flows or blocking effects. Numerical simulations of the air pollution transport are also carried out, with and without accounting for the meso-scale deformations of the wind field. The comparison of the air pollution characteristics, obtained in both the cases demonstrates that the underlying surface heterogeneity in some of the synoptic situations may have influence not only on the detailed air pollution field in the region, but also on some larger scale pollution characteristics – the total pollution quantity in the air above the countries, the mean surface concentration, the pollution fluxes trough the country boundaries, dry and wet deposition.     

徐州市城市大气中的PAHs来源解析

采用化学质量平衡模型（CMB）对徐州市大气颗粒物中的多环芳烃（PAHs）进行来源分析,从而来确定各个源对大气的PAHs贡献值。主要通过利用大流量采样器配置PM10切割头在冬季和夏季对不同功能区,即生活区、工业区和旅游区采样大气中的可吸入颗粒物（PM10）样品,并用高效液相色谱法（HPLC）重点分析和研究了美国环保局（EPA）列出的16种PHAS优先污染物。研究结果表明：徐州市PM10污染比较严重,PM10污染质量浓度水平冬季是（288.81μg·m-3）大于夏季（276.34μg·m-3）,特别是工业区,污染数值达到393.13μg·m-3。夏季的总PAHs质量浓度为22.89 ng·m-3,分别是生活区28.35 ng·m-3、工业区21.75 ng·m-3和旅游区18.58 ng·m-3。冬季的总PAHs质量浓度为306.29 ng·m-3,分别是工业区388.03 ng·m-3、生活区276.29 ng·m-3和旅游区254.28 ng·m-3。夏季和冬季情况下,旅游区的污染相对来说都是最低的PM10中多环芳烃的源解析结果为,煤烟尘污染源的全年贡献率为64.00%,冬季煤烟尘污染源的贡献率为66.51%,夏季煤烟尘污染源的贡献率为57.21%,说明煤烟尘是PM10中多环芳烃的主要贡献源,土壤尘次之,全年贡献率为24.90%,冬季为25.48%,夏季为28.97%,因此,扬尘和烟煤尘的污染是徐州市的PM10中PAHs的最主要来源。     

上海市宝山区大气降尘污染时空变化特征

为了探讨上海市宝山区大气尘降污染的时空变化特征,对上海市宝山区冬、春、秋季3个时段的大气降尘采样和分析,利用单因子指数法和空气污染指数法对宝山区降尘污染进行评价.结果表明,宝山区降尘通量为3.4-52.5 g·m~(-2)·month~(-1),各个季节的降尘总量上,春季高于冬季,秋季最低;从区域受污染范围大小看,春季>冬季>秋季,其中春季48.7%的区域受到污染;冬季最高降尘污染等级是三个季节中最高的,达到重污染水平;工业区的降尘通量和降尘污染等级都显著高于其他功能区,是宝山最主要的降尘污染源.     

化学质量平衡受体模型新技术的应用──TEDA大气颗粒物来源解析实例

本文结合实例介绍了大气颗粒物来源解析最常用的模型－化学质量平衡（ＣＭＢ）的原理、有效方差最小二乘解法及诊断检验技术，并用ＭＰＩＮ矩阵检验了拟合元素对拟合源的灵敏度，奇异值分解法（ＳＶＤ）鉴别了共线源，得出天津市经济技术开发区（ＴＥＤＡ）的ＴＳＰ主要来源为风沙、扬尘，其次为燃煤飞灰和木灰。