以绿化三维量分析植物群降解SO2的宏观效应

控制和降低城市上空ＳＯ２的环境浓度对于改善城市环境，促进城市生态的良性循环具有十分重要的意义。本文从上海市绿化三维量分布模型、与ＳＯ２浓度分布模型的相关分析入手，以季节变化作为对比因子，讨论了城市绿化植物群的数量及分布对城市上空ＳＯ２浓度分布的宏观影响；并据此提出了可有效地控制城市上空ＳＯ２浓度的绿地建设的基本原则。     

An Assessment on Variation of Sulphur Dioxide and Particulate Matter in Erzurum (Turkey)

Sulphur dioxide and PM₁₀ levels are investigated in Erzurum during the periods of 1990–2000 heating season to assess air pollution level. For that reason, emissions of sulphur dioxide and particulate matter were calculated by using consumption of fuels and Turkish emission factors. These emission values were evaluated together with air pollution levels, which were measured at six stations in Erzurum atmosphere during 1990–2000 winter periods. Results reveal that in 1990–1994 heating period, there is an increasing trend in the emissions and air pollution levels over Erzurum, and the air quality limits were not met. The daily 24 h limit (short-term limit) was exceeded 127 days in 1992–1993 winter period. The reason for this increase was found to be the switching to use of low-quality fossil fuels instead of cleaner ones. Results also indicated that there was a considerable decrease in emissions of air pollutants and air pollution levels after 1995. This can be explained by the consumption of more high-quality fossil fuels. The correlation coefficient of SO₂ with PM₁₀ is obtained as r² = 0.85, which is a high value supporting the idea that both pollutants are emitted from the same source.     

Use of Natural 35S to Trace Sulphate Cycling in Small Lakes,Flattops Wilderness Area,Colorado, U.S.A.

Measurements of the cosmogenically-produced ³⁵S, a radioisotope of sulphur (t_1/2 = 87 days), are reported for the Ned Wilson Lake watershed in Colorado. The watershed contains two small lakes and a flowing spring presumed to be representative of local ground water. The watershed is located in the Flattops Wilderness Area and the waters in the system have low alkalinity, making them sensitive to increases in acid and sulphate deposition. Time series of ³⁵S measurements were made during the summers of 1995 and 1996 (July–September) at all three sites. The system is dominated by melting snow and an initial concentration of 16–20 mBq L^-1 was estimated for snowmelt based on a series of snow samples collected in the Rocky Mountains. The two lakes had large initial ³⁵S concentrations in July, indicating that a large fraction of the lake water and sulphate was introduced by meltwater from that year's snowpack. In 1995 and 1996, ³⁵S concentrations decreased more rapidly than could be accounted for by decay, indicating that other processes were affecting ³⁵S concentrations. The most likely explanation is that exchange with sediments or the biota was removing ³⁵S from the lake and replacing it with older sulphate devoid of ³⁵S. In September of 1995 and 1996, ³⁵S concentrations increased, suggesting that atmospheric deposition is important in the sulphate flux of these lakes in late summer. Sulphur-35 concentrations in the spring water were highly variable but never higher than 3.6 mBq L^-1 and averaged 2 mBq L^-1. Using a simple mixing model, it was estimated that 75% of the spring water was derived from precipitation of previous years.     

Long Term Trends in Sulphur and Nitrogen Deposition in Europe and the Cause of Non-linearities

Emissions of sulphur and oxidized nitrogen compounds in Europe have been reduced following a series of control measures during the last two decades. These changes have taken place during a period in which the primary gases and the wet deposition throughout Europe were extensively monitored. Since the end of the 1970s, for example land based sulphur emissions declined by between 90 and 70% depending on the region. Over the same period the total deposition of sulphur and its partitioning into wet and dry deposition have declined, but the spatial pattern in the reduction in deposition differs from that of emission and has changed with time. Such non-linearities in the emission-deposition relationship are important to understand as they complicate the process of assessing the effects of emission reduction strategies. Observed non-linearities in terrestrial sulphur emission-deposition patterns have been identified in north west Europe due to increases in marine emissions, and are currently slowing the recovery of freshwater ecosystems. Changes in the relative amounts of SO₂ and NH₃ in air over the last two decades have also changed the affinity of terrestrial surfaces for SO₂ and have therefore changed the deposition velocity of SO₂ over substantial areas. The consequence of this effect has been the very rapid reduction in ambient SO₂ concentration in some of the major source areas of Europe, where NH₃ did not change much. Interactions between the different pollutants, generating non-linearities are now being incorporated in long-range transport models to simulate the effects of historical emission trends and to provide projections into the future. This paper identifies non-linearities in emission deposition relationships for sulphur and nitrogen compounds in Europe using data from the EMEP long-rang transport model and measured concentration fields of the major ions in precipitation and of SO₂ and NO₂ in surface air.     

甘肃平凉市大气湿沉降中氮、硫污染物循环特征分析

大气环境中氮,硫污染物的循环,正在自然系统改变。人为活动已明显冲击了氮、硫元素的循环过程,它们可能对生物多样性,局地气侯变暖,土壤,水体,人体健康等逐渐带来严重影响。氮、硫污染物亦是大气酸沉降的主要来源。通过对甘肃平凉市大气湿沉降中氮、硫污染物特征分析,掌握氮、硫污染物动态变化,分析它们在大气湿沉降中的化学变化及污染循环特征,为做好节能减排工作提供理论依据。使氮、硫元素的循环趋于平衡,防止酸沉降在我市发生,进一步提高我市环境空气质量。     

生物型煤固硫技术

研究出生物型煤的生产工艺流程，对型煤和生物型煤的固流效果进行了对比。成功地试验生产出固硫性能优良的生物型煤，为消除煤能源利用中的硫污染开辟了新途径。     

我国动力用煤煤灰自身固硫特性的统计分析

对１８６种我国典型动力用煤在实验室制灰条件下煤灰自身固硫特性的统计分析表明，含硫量越高的煤，其Ｃａ／Ｓ以及Ｍｇ／Ｓ、２Ｎａ／Ｓ和２Ｋ／Ｓ摩尔比一般越低，因而其煤灰固硫率也越低；钙对煤灰自身固硫起主要作用，固硫率随Ｃａ／Ｓ比的增加呈指数增加；而煤中其它碱性成分对固硫也起一定的作用．     

Tree ring analysis for determination of pollution history of Chengde City, north China

ＴｒｅｅｒｉｎｇａｎａｌｙｓｉｓｆｏｒｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｐｏｌｌｕｔｉｏｎｈｉｓｔｏｒｙｏｆＣｈｅｎｇｄｅＣｉｔｙ，ｎｏｒｔｈＣｈｉｎａ￥ＪｉａｎｇＧａｏｍｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉ...     

An estimate of the conversion rates of SO2 to SO2-4 and NO2 to HNO3+ NO3- for the evaluation air pollution in Beijing

The conversion rates of SO₂ to SO^2-₄ and NO₂ to HNO₃₊NO₃- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO₂ is about four times as much as that of SO₂; The conversion rates have a diurnal variation in a day. On the average, the rate of SO₂ is estimated to be 4.7% h^-1 during the daytime and 3.4% h^-1 during the nighttime. Similarly, the rate of NO₂ is estimated to be 17.2% h^-1 and 12% h^-1 respectively.     

The Danish eulerian hemispheric model — a three-dimensional air pollution model used for the arctic

A three-dimensional Eulerian hemispheric air pollution model, the Danish Eulerian Hemispheric Model (DEHM), is in development at the National Environmental Research Institute (NERI). The model has been used to study long-range transport of air pollution in the Northern Hemisphere. The present version of the model includes long-range transport of sulphur dioxide (SO₂) and particulate sulphate (SC₄²⁻. The chemistry in the model is described by a simple linear oxidation of SO₂ to SO₄²⁻, and the wet deposition of SO₂ and SO₄⁻ is estimated based on the amount of precipitation, which is calculated from the contents of liquid cloud water (see Christensen, Air Pollution Modelling and its Applicatioons, Vol. X, pp. 119–127, Vol. XI, pp. 249–256, Plenum press, New York; 1995, Ph.D. thesis, National Environmental Research Institute, Denmark). The model has been used to study the air pollution in the Arctic. Results from yr simulation with an analysis of the results is presented: the model results are verified by comparisons, to measurements not only from the Arctic region but also from Europe and Canada. Some examples of episodes in the Arctic including analysis of the meteorological conditions during the episodes are presented. Finally, the model has been used to estimate the contribution from the different source regions on the northern hemisphere to the Arctic sulphur pollution.