Seasonal Differences in the Levels of Gaseous Air Pollutants in the Vicinity of a Waste Dump

Hydrogen sulphide, ammonia, nitrogen dioxide, mercaptans and sulphur dioxide (H₂S, NH₃, NO₂, R-SH, SO₂) concentrations were measured at the location in the vicinity of the waste dump to determine the air pollution level of these pollutants prior to the operation of the Mobile Thermal Treatment Plant. Samples were collected over one year period. Seasonal differences, and the influence of meteorological parameters (temperature, relative humidity, pressure and wind direction) on the air pollution levels were studied. Results show relatively low concentrations of H₂S, NO₂, R-SH and SO₂, while NH₃ levels were higher compared to the guideline values. Good weather conditions (high air pressure and low relative humidity) are connected to long range transport of NO₂, while higher temperatures result in elevated NH₃ and R-SH concentrations. Because of the predominant northeast wind direction (the same as the waste dump direction), the contribution of air pollution from the direction of the waste dump at the measuring site is significant, but that does not necessarily mean that the pollutants originated from that source.     

Monitoring the effect of restoration measures in Indonesian peatlands by radar satellite imagery

In the context of the ongoing climate change discussions the importance of peatlands as carbon stores is increasingly recognised in the public. Drainage, deforestation and peat fires are the main reasons for the release of huge amounts of carbon from peatlands. Successful restoration of degraded tropical peatlands is of high interest due to their huge carbon store and sequestration potential. The blocking of drainage canals by dam building has become one of the most important measures to restore the hydrology and the ecological function of the peat domes. This study investigates the capability of using multitemporal radar remote sensing imagery for monitoring the hydrological effects of these measures. The study area is the former Mega Rice Project area in Central Kalimantan, Indonesia, where peat drainage and forest degradation is especially intense. Restoration measures started in July 2004 by building 30 large dams until June 2008. We applied change detection analysis with more than 80 ENVISAT ASAR and ALOS PALSAR images, acquired between 2004 and 2009. Radar signal increases of up to 1.36 dB show that high frequency multitemporal radar satellite imagery can be used to detect an increase in peat soil moisture after dam construction, especially in deforested areas with a high density of dams. Furthermore, a strong correlation between cross-polarised radar backscatter coefficients and groundwater levels above -50 cm was found. Monitoring peatland rewetting and quantifying groundwater level variations is important information for vegetation re-establishment, fire hazard warning and making carbon emission mitigation tradable under the voluntary carbon market or REDD (Reducing Emissions from Deforestation and Degradation) mechanism.     

Accounting for the effect of concentration fluctuations on toxic load for gaseous releases of carbon dioxide

In Great Britain, advice on land-use planning decisions in the vicinity of major hazard sites and pipelines is provided to Local Planning Authorities by the Health and Safety Executive (HSE), based on quantified risk assessments of the risks to the public in the event of an accidental release. For potential exposures to toxic substances, the hazard and risk is estimated by HSE on the basis of a “toxic load”. For carbon dioxide (CO₂), this is calculated from the time-integral of the gas concentration to the power eight. As a consequence of this highly non-linear dependence of the toxic load on the concentration, turbulent concentration fluctuations that occur naturally in jets or plumes of CO₂ may have a significant effect on the calculated hazard ranges. Most dispersion models used for QRA only provide estimates of the time- or ensemble-averaged concentrations. If only mean concentrations are used to calculate the toxic load, and the effects of concentration fluctuations are ignored, there is a danger that toxic loads and hence hazard ranges will be significantly under-estimated.This paper explores a simple and pragmatic modification to the calculation procedure for CO₂ toxic load calculations. It involves the assumption that the concentration fluctuates by a factor of two with a prescribed square-wave variation over time. To assess the validity of this methodology, two simple characteristic flows are analysed: the free jet and the dense plume (or gravity current). In the former case, an empirical model is used to show that the factor-of-two approach provides conservative estimates of the hazard range. In the latter case, a survey of the literature indicates that there is at present insufficient information to come to any definite conclusions.Recommendations are provided for future work to investigate the concentration fluctuation behaviour in dense CO₂ plumes. This includes further analysis of existing dense gas dispersion data, measurements of concentration fluctuations in ongoing large-scale CO₂ release experiments, and numerical simulations.     

基于ARCGIS的水泥行业碳排放点源分布与变化分析

首先对水泥行业产能与产量数据进行调研,对不同的工艺采用不同的CO2排放因子系统地计算了2000—2009年各点源企业水泥生产的CO2排放量,在点源企业排放量数据的基础上分析计算了各省份及全国总排放量的年度增长趋势。其次利用ARCGIS绘制了全国水泥行业排放点源年度分布图并分析了其空间分布特征,调查分析了我国水泥企业CO2排放源点源分布与变化规律,对水泥工业节能减排、发展低碳经济的工作具有重要的意义。     

矿用救生舱内二氧化碳净化特性研究

煤矿救生舱是在矿井下发生事故后保护被困矿工生存、等待救援的密闭舱室设备。在救援过程中,二氧化碳的处理是舱内空气净化系统的一项主要功能。本文对救生舱内二氧化碳净化装置的功率、吸收效率、药剂床层厚度等因素进行了一系列试验,确定了救生舱二氧化碳的最优净化方式,并通过救生舱内真人生存试验对其进行了验证。最终得出救生舱内处理二氧化碳最佳反应条件为:药剂量20kg,最佳功率为100W;间歇式工作的运行时间与停机时间比例为2:3;在救生舱内8人生存模拟实验中,得出8kg药剂可供8人使用6.1h,平均吸收速率为1.34L/min。     

WK－1A型二氧化硫自动测定仪测定烟气中SO_2的方法研究

本文研究了仪器电导法测定烟气中ＳＯ２的监测方法,并与碘量法进行了比较,提出了吸收液测定的影响及吸收液的配制方法。本方法简单快速,能够满足烟气中ＳＯ２监测工作的要求。     

分子筛孔结构对CO_2吸附性能的影响

采用巨正则蒙特卡罗方法模拟了CO_2在FAU分子筛上的吸附情况,比较了不同CO_2逸度下,CO_2在分子筛模型上的吸附位、吸附量的变化,拟合了其吸附等温线。结果表明:在吸附饱和状态下,分子筛的孔结构越大,对CO_2的吸附量越大,对于比CO_2分子更小的微孔结构,吸附几乎不发生;在低逸度下,CO_2的吸附主要发生在小孔内,随着逸度的提高,CO_2的吸附量迅速上升;在高逸度下,吸附量的提高主要发生在大孔内;FAU分子筛吸附CO_2的过程符合Ⅰ型Langmuir吸附等温线,在高压下对CO_2的吸附能力远大于低压下的吸附能力。     

中国工业SO2排放量动态变化分析

中国工业SO2减排工作的重点。经济增长、经济空间结构变化、技术进步是影响污染物排放量变化的三个重要因素。在分析我国工业SO2排放量、排放结构、排放强度等变化趋势的基础上,通过构建对数平均权重分解模型定量分解经济增长、结构变化、技术进步这3个因素对工业SO2排放量变化的贡献。结果表明：（1）中国工业SO2排放量年均增长48.7×10^4 t,年均增长率为3.2%,且2002—2006年增速加快;（2）分地区看,1991年以来,东部地区SO2排放量所占比重明显下降,中部地区略有上升,而西部地区所占比重增加显著;（3）单位产值工业SO2排放强度在研究期内迅速降低,年均下降幅度为8.4%,对减缓SO2排放量的过快增长起到了积极作用;（4）经济增长平均每年促进SO2排放量增长183.7×10^4 t,技术进步则平均每年使SO2排放量减少134.2×10^4 t,空间结构因素平均每年减少SO2排放量0.8×10^4 t。可以看出,长期以来,虽然我国的技术水平有了一定程度提高,但经济规模的扩张使中国工业SO2排放量持续增长,对中国环境压力形成了巨大压力,同时,经济总量在不同地区的分配对SO2排放量的影响也在不断变化中。     

广州市园林绿化植物苗木对二氧化硫和二氧化氮吸收能力分析

采用人工模拟熏气法,研究了36种广州市园林绿化植物对SO2和NO2气体吸收净化能力,以系统聚类分析方法为依据,将参试植物的吸收净化能力划分为强性、较强、中等、较弱及弱5个等级。结果显示,在不同SO2质量浓度（0.259和0.448 mg.m-3）环境下,黄槐、鸡冠刺桐、红花银桦、木棉、红千层、大花紫薇、复羽叶栾树吸收SO2能力具有强或较强的能力,而罗汉松、竹柏、深山含笑、乐昌含笑、观光木、樟树、阴香、双翼豆、印度紫檀、大花五桠果、长芒杜英、五月茶、海南蒲桃、芒果、海南红豆、糖胶树和幌伞枫吸收SO2能力表现为较弱或弱;在NO2质量浓度（0.149和0.428 mg.m-3）环境下,黄槐、黄葛榕、红花银桦、红千层、麻楝、复羽叶栾树、大花紫薇和小叶榄仁吸收净化NO2能力为较强或强,而深山含笑、五月茶、芒果、海南红豆、糖胶树和桂花叶片对NO2吸收能力表现为较弱或弱。在不同SO2和NO2浓度环境下,黄槐、红花银桦、红千层、复羽叶栾树和大花紫薇叶片对SO2和NO2吸收净化能力表现为强或较强,而深山含笑、五月茶、芒果、海南红豆、糖胶树叶片对SO2和NO2吸收净化能力为较弱或弱。研究结果为珠三角城市功能型园林植物选择和广东生态景观林带建设提供科学依据。     

园林绿化树种香樟叶片的含硫量动态分析

植物对一定浓度范围内的大气污染物,具有一定程度的抵抗及吸收净化作用。为了解南京市主要园林绿化树种香樟（Cinnamomum camphora）叶片吸收净化SO2的能力,选择在5个不同污染靶区,以3个不同胸径级的香樟叶片为研究对象,采用硫酸钡比浊法测定了不同季节香樟叶片的含硫量。结果表明：香樟叶片对SO2具有一定的吸收净化能力,其叶片含硫量平均为0.2160%,且其含量随分布区、生长季节及个体胸径不同差异显著;并与异域大气中SO2污染指数成一定的正相关;与个体胸径大小成显著负相关;季节间呈现出＂先降后升再降＂的动态趋势,于春秋季较高,而夏冬季较低。