中部城市群二氧化硫扩散模型的建立

应用CALPUFF中尺度空气质量扩散模式，建立辽宁中部城市群地区二氧化硫扩散模型，成功地模拟了区域二氧化硫的污染状况。     

沈阳地区二氧化硫污染分析

本文利用常规气象资料,SO_2连续监测的数据和电子计算机计算的结果,从污染气象学的角度对沈阳地区二氧化硫污染进行了分析。沈阳地区二氧化硫浓度的日变化和风速的日变化呈明显的负相关,风速在中午13时达最大值,风速曲线呈单峰状。浓度曲线在中午左右出现波谷,冬季二氧化硫污染的日变化有两个高峰。沈阳地区地势平坦,在风速大于2m/s 时,水平风场是均匀的,采用烟羽模式计算是适合的。沈阳地区出现重污染时的天气形势符合普遍性的规律,本地特点是在出现长白山小高压时二氧化硫污染最重,这是本地区值得注意的特殊性。     

谈谈二氧化硫污染地区的绿化

二氧化硫是对人体健康有害的气体。在以煤作为工业和生活燃料的地区,二氧化硫对空气的污染是个普遍存在的问题。在以石油为燃料的地区,二氧化硫的污染同样存在。因此,如何对二氧化硫进行净化,对于保护城市和工矿区的环境是个重要课题。一些大量产生二氧化硫尾气的工厂,应该注意净化和回收利用二氧化硫。但是,总会有一部分排放到空气中来。因此,利用生物尤其是植物来净化空气中的二氧化硫是一种重要的补充手段。植物在进行光合作用和呼吸的过程中,可以把二氧化硫     

瑞典中部法伦地区1000年铜生产对环境的影响

瑞典中部的法伦地区在铜生产过程中向大气中排放二氧化硫(SO2)和金属的历史至少有1000年.在17世纪,排放达到高峰,当时,法伦地区铜产量占世界铜供应量的2/3.因此,该地区为研究酸沉降和金属污染的长期效应,包括随后3个世纪降低二氧化硫排放和金属沉降的恢复提供了一个难得的机会.本文对当地二氧化硫的排放进行了1000年的回顾,估算了二氧化硫的大气浓度和干沉降,及对土壤和湖泊的酸化和金属污染.尽管长期以来二氧化硫的沉降超过了临界负荷,但土壤酸化仅局限于矿区西北和东南12km污染最严重的范围内.根据湖泊沉积物中的硅藻分析,14个湖泊中仅有8个为酸化型(0.4～0.8pH单位).可能是由于大量的硫酸盐仍然累积在土壤中,以及土地利用方式发生了变化,这些湖泊目前仍处于酸化状态.     

珠江三角洲地区酸雨污染简析

以珠江三角洲地区主要城市的降水常规监测数据资料为依据,简要分析了该地区降水酸度和酸雨频率年度变化情况,并对酸雨的危害进行了初步的探讨。研究结果表明:该地区酸雨污染依然严重,降水酸度与二氧化硫污染等因素有关,酸雨类型以硫酸型为主。      

烧结过程SO_2排放预测模型研究

本文以物料平衡法为基础,对炼铁厂烧结工序进行解析,结合经验估算法的分配因子,耦合生产过程的物质流、能量流,建立了烧结二氧化硫排放预测模型,并以马钢三铁厂为例,验证了该二氧化硫排放预测模型,并从操作参数和预测公式两方面进行了排放模型的优化。     

二氧化硫在三聚氰胺浆液中的吸收

测定和在理论上分析了二氧化硫和三聚氰胺浓度对三聚氰胺浆液吸收二氧化硫速度的影响。二氧化硫与三聚氰胺水溶液反应生成水合亚硫酸三聚氰胺,这种几乎不可逆的反应产生一种沉淀,该沉淀可在100～200℃热分解而完全再生三聚氰胺,并产生二氧化     

定电位电解法测定SO2过程中出现的问题及解决方式

摘要：目前,环境监测部门对烟道内二氧化硫浓度的测定普遍采用定电位电解法来完成。其主要原理是二氧化硫气体在传感器的电解槽内发生氧化原反应,通过产生的扩散电流确定二氧化硫浓度,此方法快捷、简便,但准确程度却受到多方面因素影响。本文即对影响该方法准确程度的诸多因素做系统分析,并对检测过程应注意的环节做简要说明。     

氨的湿去除及氨在酸雨中的作用

为定量说明氨的湿去除,应用GR模式模拟了各种情况下氨的湿去除。结果表明:对氨的湿去除,影响最大的因素是成云过程中液体水含量和降雨过程中的雨强;氨在酸雨中有着重要的作用,氨能有效地增加云水和雨水的pH值,因而能加速二氧化硫在水中的溶解和臭氧对4价硫的氧化,最终加速了二氧化硫的湿去除。模式结果还表明,在典型的情况下,氨的湿去除速率为每小时52%。      

葫芦岛市工业源二氧化硫普查结果分析与对策

通过对葫芦岛市工业源二氧化硫普查结果全面系统分析,阐明了各区域、行业、企业的二氧化硫产生、排放及分布特点,指出了葫芦岛地区工业源二氧化硫存在的主要问题,提出了具体的对策措施。     

Characteristics and recent trends of sulfur dioxide at urban, rural, and background sites in North China: Effectiveness of control measures

SO₂ measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO₂ at different types of sites in Northern China. The overall average concentrations of SO₂ are (16.8 ± 13.1) ppb, (14.8 ± 9.4) ppb, and (7.5 ± 4.0) ppb at China Meteorological Administration (CMA, Beijing urban area), Gucheng (GCH, relatively polluted rural area, 110 km to the southwest of Beijing urban area), and Shangdianzi (SDZ, clean background area, 100 km to the northeast of Beijing urban area), respectively. The SO₂ levels in winter (heating season) are 4-6 folds higher than those in summer. There are highly significant correlations among the daily means of SO₂ at different sites, indicating regional characteristics of SO₂ pollution. Diurnal patterns of surface SO₂ at all sites have a common feature with a daytime peak, which is probably caused by the downward mixing and/or the advection transport of SO₂-richer air over the North China Plain. The concentrations of SO₂ at CMA and GCH show highly significant downward trends (-4.4 ppb/yr for CMA and -2.4 ppb/yr for GCH), while a less significant trend (-0.3 ppb/yr) is identified in the data from SDZ, reflecting the character of SDZ as a regional atmospheric background site in North China. The SO₂ concentrations of all three sites show a significant decrease from period before to after the control measures for the 2008 Olympic Games, suggesting that the SO₂ pollution control has long-term effectiveness and benefits. In the post-Olympics period, the mean concentrations of SO₂ at CMA, GCH, and SDZ are (14.3 ± 11.0) ppb, (12.1 ± 7.7) ppb, and (7.5 ± 4.0) ppb, respectively, with reductions of 26%, 36%, and 13%, respectively, compared to the levels before. Detailed analysis shows that the differences of temperature, relative humidity, wind speed, and wind direction were not the dominant factors for the significant differences of SO₂ between the pre-Olympics and post-Olympics periods. By extracting the data being more representative of local or regional characteristics, a reduction of up to 40% for SO₂ in polluted areas and a reduction of 20% for regional SO₂ are obtained for the effect of control measures implemented for the Olympic Games.     

北京地区一次大气环境持续严重污染过程中SO2的垂直分布分析

在2004-09-27～2004-10-12期间,以325m气象与环境观测塔为平台,使用43CTL型高精度脉冲荧光SO₂分析仪,分别布置在观测塔8m、47m、120m和280m 4层观测平台,对大气中的SO₂气体浓度、PM₁₀和PM_2.5粒子质量浓度及同步气象因素进行了垂直梯度、连续观测.结合气象数据分析了观测期间大气中SO₂气体浓度的垂直梯度分布及变化形势,进行了SO₂浓度与混合层高度变化、海平面气压变化,风速、风向变化等要素的相关分析,观测到在实验期间大气边界层中SO₂浓度由上向下递减分布的现象.由于地形与污染源分布的影响,北风最有利于污染扩散等状况.观测期间捕捉到一次主要由气象因素造成的大气环境严重持续污染及污染清除的全过程.     

Physico-chemical study by two aircraft of a plume from a coal-fired power plant

During the experimental field program that was conducted in October 1985 ton study the physics and chemistry of the Le Havre power plant plume, joints flights were performed with two aircraft from EDF and KEMA. The two episodes with very different meteorological conditions were investigated. The first episode was characterized by fairly constant wind speed and direction with altitude, low solar irradiation and neutral vertical dispersion conditions. The second episode was characterized by low wind speed and changing wind direction, high solar irradiation and stable vertical dispersion conditions. During the latter episode, the concentrations of emitted gases, SO₂ and NO_x remained high, even at several tens of km downwind of the stock. Increased SO₄^2- and NO₃^- concentrations were detected in the power plant plume. In addition, important photochemical activity took p-lace in the plume of a nearby industrial area. The former episode showed more significantly vertical dilution and oxidation of NO but did not reveal any contribution of the power plant plume to aerosol formation.     

V2O5/AC催化剂脱除烟气中SO2的微观动力学研究

利用热重分析仪对V2O3/AC脱除SO2的微观动力学进行了研究,考察了催化剂V2O5的含量[w(V2O5)]、反应物SO2和H2O的浓度[ψ(SO2)和ψ(H2O)]及反应温度对催化剂增重分率的影响,并采用微孔填充模型描述V2O5/AC的脱硫行为.模型研究表明:V2O5/AC脱除SO2反应速率由吸附-催化剂表面化学反应控制,SO2和H2O的吸附可用Langmuir-Hinshelwood模型分析.将活性组分表面分率和V2O5/AC的微孔孔容随反应的变化用参数n表示,n类似于反应级数,以表示二者对反应的影响程度.     

Vertical distributions of tropospheric SO2 based on MAX-DOAS observations: Investigating the impacts of regional transport at different heights in the boundary layer

Information on the vertical distribution of air pollutants is essential for understanding their spatiotemporal evolution underlying urban atmospheric environment. This paper presents the SO₂ profiles based on ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements from March 2018 to February 2019 in Hefei, East China. SO₂ decrease rapidly with increasing heights in the warm season, while lifted layers were observed in the cold season, indicating accumulation or long-range transport of SO₂ in different seasons might occur at different heights. The diurnal variations of SO₂ were roughly consistent for all four seasons, exhibiting the minimum at noon and higher values in the morning and late afternoon. Lifted layers of SO₂ were observed in the morning for fall and winter, implying the accumulation or transport of SO₂ in the morning mainly occurred at the top of the boundary layer. The bivariate polar plots showed that weighted SO₂ concentrations in the lower altitude were weakly dependent on wind, but in the middle and upper altitudes, higher weighted SO₂ concentrations were observed under conditions of middle-high wind speed. Concentration weighted trajectory (CWT) analysis suggested that potential sources of SO₂ in spring and summer were local and transported mainly occurred in the lower altitude from southern and eastern areas; while in fall and winter, SO₂ concentrations were deeply affected by long-range transport from northwestern and northern polluted regions in the middle and upper altitudes. Our findings provide new insight into the impacts of regional transport at different heights in the boundary layer on SO₂ pollution.     

SO_2体积分数对ZL50活性炭吸附脱硫行为的影响和动力学分析

通过动态吸附烟气脱硫实验,考察了烟气中不同SO2体积分数对ZL50脱硫脱硝活性炭脱硫行为的影响,并进行了动力学分析.随着烟气中SO2体积分数增大,脱硫率和ZL50脱硫脱硝活性炭的活性度下降;SO2吸附量和吸附速率增大.模拟结果表明,Bangham模型模拟效果最优,SO2的催化氧化反应对化学吸附有重要影响;Lagergren准一级吸附速率常数随SO2进口体积分数的增加而增大,表明SO2的催化氧化反应在吸附前期可能为速控步骤.推导和定义了Lagergren模型和Bangham模型的初始吸附速率;推导了文献上的Ho模型和Elovich模型的初始速率式。定义的Bangham初始吸附速率与初始吸附速率实验值吻合最好;建立的Bangham吸附反应动力学模型能较好地描述SO2动态吸附速率.结果表明,SO2的初始反应速率分级数为1或接近1,而O2和水蒸气的初始速率分级数分别为0.15～0.20和0.45～0.50之间的常数.     

The effect of wind velocity,air temperature and humidity on NH3 and SO2 transfer into bean leaves (phaseolus vulgaris L.)

The influence of wind velocity, air temperature and vapour pressure deficit of the air (VPD) on NH₃ and SO₂ transfer into bean leaves (Phaseolus vulgaris L.) was examined using a leaf chamber. The measurements suggested a transition in the properties of the leaf boundary layer at a wind velocity of 0.3–0.4 ms⁻¹ which corresponds to aRe_crit value of about 2000. At higher wind velocities the leaf boundary layer resistance (r_b) was 1.5–2 times lower than can be calculated from the theory. Nevertheless, the assessed relationships betweenr_b and wind velocity appeared to be similar to the theoretical derived relationship forr_b. The NH₃ flux and in particular the SO₂ flux into the leaf strongly increased at a VPD decline. The increase of the NH₃ flux could be attributed to an increase of the stomatal conductance (g_s). However, the increase of the SO₂ flux could only partly be explained by an increase ofg_s. An apparent additional uptake was also observed for the NH₃ uptake at a low temperature and VPD. The SO₂ flux was also influenced by air temperature which could be explained by a temperature effect ong_s. The results suggest that calculation of the NH₃ and SO₂ flux using data ofg_s gives a serious understimation of the real flux of these gases into leaves at a low temperature and VPD.     

水蒸气电晕放电下的烟气脱硫效果

采用多针-板式电极,在70 m³/h烟气流量范围内,研究了水蒸气浓度、烟气流量、电场强度等因素对不饱和水蒸气正直流电晕放电烟气脱硫率的影响以及水蒸气电晕放电对脉冲放电烟气脱硫率的提高.研究结果表明,实验范围内,按照NH₃∶SO₂摩尔比为2∶1添加NH3的条件下,增加水蒸气流量、增强电场强度、减少烟气流量,烟气脱硫率能提高10%,达到60%左右.同时,水蒸气电晕放电能使脉冲放电的烟气脱硫率提高5%左右,达到90%以上.     

Heterogeneous sulfur conversion in sea-salt aerosol particles: the role of aerosol water content and size distribution

Meteorological and chemical conditions during the July 1988 Bermuda-area sampling appear to have been favorable for conversion of sulfur gases to particulate excess sulfate (XSO₄). Observed average XSO₄ and SO₄ concentrations of 11 and 2.1 nmol m⁻³, respectively, at 15 m a.s.l. in the marine boundary layer (MBL) upwind of Bermuda, indicate that conversion of SO₂ to XSO₄, over and above homogeneous conversion, may be necessary to explain the > 5.0 average molar ratio of XSO₄ to SO₂. Given an observed cloud cover of <15% over the region and the <3 nmol m⁻³ SO₃ concentrations observed by aircraft, heterogeneous conversion mechanisms, in addition to cloud conversion of SO₂, are necessary to explain the observed 11 nmol XSO₄ m⁻³.Aerosol water content, estimated as a function of particle size distribution plus consideration of SO₂ mass transfer for the observed particle size distribution, shows that SO₂ was rapidly transferred to the sea-salt aerosol particles. Assuming that aqueous-phase SO₂ reaction kinetics within the high pH sea-salt aerosol water are controlled by O₃ oxidation, and considering mass-transfer limitations, SO₂ conversion to XSO₄ in the sea-salt aerosol water occurred at rates of approximately 5% h⁻¹ under the low SO₂ concentration, Bermuda-area sampling conditions. All of the 2 nmol XSO₄ m⁻³ associated with sea-salt aerosol particles during low-wind-speed, Bermuda-area sampling can be explained by this conversion mechanism. Higher wind speed, greater aerosol water content and higher SO₂ concentration conditions over the North Atlantic are estimated to generate more than 4 nmol XSO₄ m⁻³ by heterogeneous conversion of SO₂ in sea-salt aerosol particles.     

Emission inventory evaluation using observations of regional atmospheric background stations of China

Any accurate simulation of regional air quality by numerical models entails accurate and up-to-date emissions data for that region.The INTEX-B2006 (I06),one of the newest emission inventories recently popularly used in China and East Asia,has been assessed using the Community Multiscale Air Quality model and observations from regional atmospheric background stations of China.Comparisons of the model results with the observations for the species SO2,NO 2,O 3 and CO from the three regional atmospheric background stations of Shangdianzi,Longfengshan and Linan show that the model can basically capture the temporal characteristics of observations such as the monthly,seasonal and diurnal variance trends.Compared to the other three species,the simulated CO values were grossly underestimated by about two-third or one-half of the observed values,related to the uncertainty in CO emissions.Compared to the other two stations,Shangdianzi had poorer simulations,especially for SO2 and CO,which partly resulted from the site location close to local emission sources from the Beijing area;and the regional inventory used was not capable of capturing the influencing factors of strong regional sources on stations.Generally,the fact that summer gave poor simulation,especially for SO2 and O 3,might partly relate to poor simulations of meteorological fields such as temperature and wind.