The solubility and behaviour of acid gases in the marine aerosol

The following Henry's law constants (K _H/mol²kg^-2atm^-1) for HNO₃ and the hydrohalic acids have been evaluated from available partial pressure and other thermodynamic data from 0°–40°C, 1 atm total pressure: HNO ₃ , 40°C–5.85×10⁵; 30°C–1.50×10⁶; 25°C–2.45×10⁶; 20°C–4.04×10⁶; 10°C–1.15×10⁷; 0°C–3.41×10⁷. HF, 40°C–3.2; 30°C–6.6; 25°C–9.61; 20°C–14.0; 10°C–32.0; 0°C–76. HCl, 40°C–4.66×10⁵; 30°C–1.23×10⁶; 25°C–2.04×10⁶; 20°C–3.37×10⁶; 10°C–9.71×10⁶; 0°C–2.95×10⁷. HBr, 40°C–2.5×10⁸; 30°C–7.5×10⁸; 25°C–1.32×10⁹; 20°C–2.37×10⁹; 10°C–8.10×10⁹; 0°C–3.0×10¹⁰. HI, 40°C–5.2×10⁸; 30°C–1.5×10⁹; 25°C–2.5×10⁹; 20°C–4.5×10⁹; 10°C–1.5×10¹⁰; 0°C–5.0×10¹⁰. Simple equilibrium models suggest that HNO₃, CH₃SO₃H and other acids up to 10x less soluble than HCl displace it from marine seasalt aerosols. HF is displaced preferentially to HCl by dissolved acidity at all relative humidities greater than about 80%, and should be entirely depleted in aged marine aerosols.     

邓阜仙花岗岩熔融实验研究

本文通过对邓阜仙花岗岩饱和水熔融实验结果的计算处理和岩石学相图的分析,从实验岩石学的角度证实了邓阜仙花岗岩是岩浆结晶的,而不是花岗岩化形成的。同时,由实验表明,岩石初熔温度除与岩石成分有关外,还与岩石实际形成条件有密切联系。此外,在加氟化物的饱和水熔融实验中,氟化物不仅能降低岩石初熔温度,而且改变了岩浆体系中不同矿物的稳定性,主要使云母和石英变得稳定,酸性斜长石变得不稳定,而钾长石的稳定性基本不变。     

Controls on the genesis of a high-fluoride thermal spring: Innot Hot Springs,north Queensland *

This study reports on the source, evolution, reactions and environmental impacts of F-rich thermal water at Innot Hot Springs, north Queensland. Thermal water of the Innot Hot Springs has a surface temperature of 71°C, alkaline pH (8.1), low dissolved oxygen (0.61 mg/L) and low total dissolved solids (652 mg/L). The main chemical composition is Na – Cl, with F concentrations (16 mg/L) being comparatively high. Concentrations of alkali and alkali-earth metals (Cs, Li, Rb, Sr) are elevated, while those of other trace elements (Ag, Al, As, Ba, Be, Cr, Cu, Ga, Mn, Mo, U, Zn) are significantly less. Hydrochemical and stable isotope data of hot spring water show that the fluid is meteoric in origin and has undergone significant water – granite interaction. Common geothermometers suggest temperatures of water – rock interaction at depth in the 119 – 158°C range (corresponding to a depth of <3.9 – 5.2 km). Solubility modelling of the thermal fluid demonstrates that the evolution of F concentrations in spring waters at the discharge site can be accounted for by fluid – rock interaction of a H₂O – NaCl solution with fluorite – calcite-bearing granite assemblages between 150 and 200°C and subsequent granite-buffered cooling. Modelling also indicates that the F concentration in the hydrothermal system is largely controlled by interactions with fluorite, with less evidence for the significant involvement of F-topaz. Speciation calculations demonstrate that F speciation in the fluid is dominated by F^? (99.4%), followed by minor CaF⁺ (0.5%) and NaF_(aq) (0.1%), and traces of other F complexes. Thus, the F-rich Innot Hot Springs result from meteoric water circulating through fluorite-bearing granitic rocks and are the surface expression of a low-temperature, non-volcanic geothermal system. Discharge of the hot spring water occurs into an ephemeral stream located in a seasonally wet – dry tropical climate. As a result, the F content of local surface waters is distinctly elevated (max. 18 mg/L) during the dry season, making them unsuitable for stock water supplies.     

Distribution of Aluminum and Fluoride in Tea Plant and Soil of Tea Garden in Central and Southwest China

The distribution of Al and F contents and the relationship between Al and F in tea plants and soils of 12 tea gardens in Central and Southwest China were investigated from October 31 to November 14, 2006. The results show that there were differences in pH, CEC, the contents of organic matter (OM), Al and F in the different soils of the tea gardens. The Al content ranged from 1196 to 7976mg/kg for old leaf, 370 to 2681mg/kg for young leaf and 285 to 525mg/kg for stem, whereas the content of F ranged from 221 to 1504mg/kg for old leaf, 49 to 602mg/kg for young leaf and 13.5 to 77.5mg/kg for stem. The concentrations of labile Al varied obviously in the different soils, but the distribution law of labile Al content for the same garden was Alexchangeable≈AlFe-Mn oxide>Alorganic>Alwater-soluble. The contents of different labile F fractions varied slightly in the different soils and the different soil layers, though the exchangeable F content was lowest among the labile F in the soils. The concentrations of Al and F in tea plants increased with increasing amount of water-soluble Al or F, especially the amount of water-soluble fractions in the soil layer of 0-20cm.The correlation between Al content and F content in the tea leaf was more significant than that in the tea stem. Furthermore, the correlation between Al content and F content in whole tea plant was strongly significant (r=0.8763, p<0.01, n=36). There were evident tendency that Al concentration increased with the increase of F concentration in different soil layers. The correlation of water-soluble Al with water-soluble F in all soils was also strongly significant (r=0.7029, p<0.01, n=34). The results may provide a proof that Al and F are jointly taken up by tea plants to some extent in natural tea gardens.     

贵州织金荷花村拌煤粘土的氟化氢潜在释放

贵州织金县城关镇荷花村的地表土(拌煤粘土)曾被证实普遍高氟且被认为与地氟病长期严重流行密切相关。本文新的研究证实:该村拌煤粘土的氟含量均值为1284μg/g(620.8~2816μg/g,n=45);表观酸度均值为p Ha=4.92(4.03~6.35,n=45),而实际酸度均值达到3.67(2.09~5.03,n=45);实测硫酸根总量均值为4465μg/g(1165~7003μg/g,n=45),且酸度与硫酸根总量呈正相关(相关系数:0.7920),表明该村拌煤粘土含氟量较高且已酸化,酸的存在形式可能是酸性硫酸盐如Na HSO4。据此推论,这里的拌煤粘土在与煤共燃烧或被加热条件下,酸性硫酸盐可能分解煤和粘土中氟化物而释放出氟化氢,且根据酸碱平衡估算出了氟化氢释放量均值为455μg/g(9.1~1643μg/g,n=45)。类似现象在其他地氟病流行区是否具有普遍性有待进一步研究。     

Gas and particle emissions from Soufrière Hills Volcano, Montserrat, West Indies: characterization and health hazard assessment

 The Soufrière Hills Volcano, Montserrat, erupting since 18 July 1995, intensified its degassing in early 1996 with the continuing growth of the lava dome inside the summit crater. During this period of increased activity, between 11 and 18 March 1996, we measured gases and particles within the visible plume to determine whether at that time it posed a health risk to the population of Plymouth, the capital town, which is 5 km southwest (downwind) and was then still occupied. Gravimetric measurements were made of total suspended particles (TSP) and particles having an aerodynamic diameter of less than 10 μm (PM₁₀). Measurements were made of sulphur dioxide (SO₂), hydrochloric acid (HCl), hydrofluoric acid (HF), nitric acid (HNO₃), acetic acid (CH₃COOH), formic acid (HCOOH), and particulate sulphate (SO₄ ^2–), chloride (Cl^–), nitrate (NO₃ ^–), fluoride (F^–), methanesulphonate (CH₃SO₃ ^–), acetate (CH₃COO^–), formate (HCOO^–), ammonium (NH₄ ⁺), sodium (Na⁺) and acidity (H⁺). Trace metals having human health implications [chromium (Cr), nickel (Ni), cobalt (Co), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), tin (Sn), mercury (Hg) and lead (Pb)] were also determined. Mean concentrations of HCl, SO₂ and HF obtained in the town of Plymouth were 14.0, 5.9 and 0.8 ppbv, respectively. Corresponding concentrations in the mixed plume on the crater edge were 533, 168 and 22 ppbv. There were no direct emissions of HNO₃, although nitrate was detected in coarse particles at the source. Higher concentrations of CH₃COOH and HCOOH were measured close to the crater. Mean TSP and PM₁₀ were 64 and 15 μg m^–3 in Plymouth, and 455 and 47 μg m^–3 on the upper volcano slope. Aerosols were highly acidic at the source but rapidly neutralised during transport. Trace metals were enriched in the aerosol relative to crater surface material. The concentrations of the acid gases, sulphur dioxide in particular, and particles were found to be too small to pose a health hazard at the time of these measurements, when relatively modest volcanic activity was occurring. Received: 9 September 1998 / Accepted: 29 August 1999     

黄河口及渤海西南部水体中氟含量

作者根据1984年6月的现场调查,研究了黄河口及渤海西南部水体中氟的含量和行为,结果如下: 一、渤海西南部海水的F:Cl比的平均值为3.8×10~(-5)(S≥25),其值随盐度的降低而增加。 二、黄河水氟含量为0.54mg/kg,高于世界上一些未污染的河水及长江水。 三、黄河口水氟含量与盐度间具有很好的线性关系,因此河口水中氟是一保守成分     

低聚合羟基铁离子-蒙脱石复合体吸附磷和氟的实验研究

将提纯的钙蒙脱石与羟基铁离子溶液作用，制备了低聚合羟基铁-蒙脱石复合体。在实际土壤的酸度(pH=4～8)和温度(t=34～50℃)条件下，进行了低聚合羟基铁-蒙脱石复合体吸附P和F的实验，探讨了复合体的P和F吸附能力与pH值、温度、吸附时间、P和F的初始浓度、离子强度间的关系，并与蒙脱石和含水氧化铁的P和F吸附行为进行了对比。研究表明，在实验条件下，低聚合羟基铁-蒙脱石复合体对磷具有明显的亲合力，对氟的亲合力较低，只略高于蒙脱石原样。低聚合羟基铁-蒙脱石复合体对P和F的吸附，特别是对磷的吸附行为对该元素在土壤中的迁移过程有重要影响，成果对土壤学和环境学研究有参考价值。     

Vertical Column Abundances of COF2 Above the Jungfraujoch Station, Derived from Ground-Based Infrared Solar Observations

Total vertical column abundances of carbonyl fluoride (COF₂) have been derived from observations made at the International Scientific Station of the Jungfraujoch (ISSJ; altitude 3.58 km, latitude 46.5°N, longitude 8.0°E), Switzerland. A systematic analysis of two microwindows containing lines of the ₁ band was performed, based on a large set of high resolution infrared solar absorption spectra recorded with Fourier transform spectrometers, from 1985 to 1995. Examination of the whole available database indicates a significant increase of the burden of COF₂ during the 1988–1995 period. The average exponential rate and the average linear rate referenced to 1992, calculated from daily mean measurements, are both equal to (4.0 ± 0.5)% yr^-1 (one error). The results are also evaluated and discussed within the context of seasonal variability and correlation between carbonyl fluoride and hydrogen fluoride (HF) columns above the ISSJ.     

氟化盐母液综合利用及效益分析

以湿法生产氟化盐工艺过程中所排放的母液为原料,利用母液中的氟、铝和硅等资源,采用化工同元溶解的原理,其工艺路线为氯化钠脱硅—脱硅后的母液合成冰晶石—加石灰中和除氟、除酸。其关键技术为氯化钠脱硅:投入过量氯化钠,使母液中氟硅酸根转化成副产品氟硅酸钠,母液被精制;再加入精制氢氟酸与各形态铝合成冰晶石副产品,从而有效地提高了氟、铝和硅的收率。半工业化实验结果表明:计算年产4 000 t氟化铝产品的母液,企业可回收产品氟化铝140 t,生产副产品氟硅酸钠238 t、冰晶石206 t、中和残渣375 t,每年可获效益140万元人民币。