江苏省2006年酸雨分布特征及其与气象条件的关系分析   总被引：9，自引：4，他引：5  

吴洪颜  濮梅娟  商兆堂  孔一江 《气象科学》2008,28(5):563-567

统计江苏省4个酸雨监测站2006年的酸雨监测资料得到:徐州、南京的年酸雨发生频率高于常年同期,年平均pH值低于常年同期;常州、淮安的年酸雨发生频率比常年同期偏少,年平均pH值高于常年同期;各站的月酸雨发生频率呈逐月上升趋势,秋冬季酸雨发生频次均高于历史同期.结合同步的气象要素分析发现,降水强度、风、前期气候状况以及天气系统等都与酸雨的发生有密切关系.  相似文献   

Acid drainage generation and associated Ca-Fe-SO₄ minerals in a periglacial environment, Eagle Plains, Northern Yukon, Canada: A potential analogue for low-temperature sulfate formation on Mars     

Denis Lacelle  Richard Léveillé 《Planetary and Space Science》2010,58(4):509-843

Near Eagle Plains, northern Yukon, Canada, acidic Ca-Fe-Mg sulfate waters are discharging year-long from disturbed permafrosted sandstone bedrock overlying pyritiferous black shales. These acidic waters are precipitating gypsum with minor amounts of jarosite-K (Na), schwertmannite and hematite. This mineral assemblage is similar to that observed at Meridiani Planum (and other location on Mars), making this site a valuable analogue for low-temperature sulfate geochemistry and mineral formation on Mars. Stable O-S isotope analysis of the acidic waters near Eagle Plains revealed that the oxygen in the dissolved sulfate is mostly derived from water (ca. 70%), suggesting that the sulfide oxidation process could be in part biomediated (i.e., accelerated by acidophilic Fe-oxidizing bacteria). However, unlike the dissolved sulfate in the waters, the formation of the Ca-Fe-SO₄ minerals appears to be purely abiotic. The stable O-S isotope composition of the sulfate minerals is well within the predicted equilibrium range at low temperature, suggesting that they formed through physico-chemical processes (i.e., evaporation or freezing). Low-temperature geochemical modeling with FREZCHEM and PHREEQC suggests that the mineral assemblage at Eagle Plains precipitated mainly through the freezing of Ca-Fe-Mg-SO₄ acidic waters, rather than through evaporation during the dry summer season, although the latter is still possible. This suggests that the sulfate mineral assemblage observed on Mars could have also formed under a periglacial-type climate. Considering that the active layer in the zone affected by acid drainage does not freeze-over during winter, the residual talik offers a localized niche environment to support acidophilic microorganisms. Overall, the fact that acid drainage is presently active near Eagle Plains allows the direct observation of the low-temperature geochemical processes responsible for generating acid drainage conditions and precipitation of gypsum, schwertmannite, jarosite-K, jarosite-Na, goethite and hematite.  相似文献   

腐植酸泥浆正交试验优化研究     

石朋飞  乌效鸣  符碧犀 《岩土钻凿工程》2010,(2):49-52

腐植酸泥浆是非开挖钻进砂层、砾石、卵石以及破碎地层时常用的一种护壁浆液。针对常用的腐植酸泥浆的配方,设计了四因素三水平的正交试验,分析了泥浆性能受各组分影响的主次,然后进行配方优化。把NaCl作为一个正交试验因素,分析了NaCl不同加量对泥浆性能的影响。正交优化后的泥浆性能粘度较高,失水量较小,能较好的满足施工的要求。  相似文献   

Speciation of aluminum in the stream waters from the Susquehanna River watershed, Chesapeake Bay     

Shuping Bi 《Environmental Geology》2001,40(3):300-304

 The aim of this paper was to analyze the processing and transport of aluminum speciation through the terrestrial and aquatic ecosystems of the Chesapeake Bay landscape. Stream waters were sampled in 14 different streams from the Susquehanna River watershed to the upper reach of Chesapeake Bay. The basic water quality data were documented and Al speciation was evaluated by modified MINEQL computer model. It was found that the increase in acidity in some of the stream waters near New York were closely linked with a marked decline in basic cation concentrations. In these areas, the sum of the toxic forms of Al³⁺ plus AlOH²⁺ and Al(OH)₂ ⁺ concentrations exceeds the critical level of 5 μmol l^–1. A potential threat from aluminum may occur. Received: 3 January 2000 · Accepted: 21 March 2000  相似文献   

胶州湾养殖海区沉积物中酸可挥发性硫的研究   总被引：19，自引：1，他引：19  

霍文毅  李全生  马锡年 《地理科学》2001,21(2):135-139

沉积物中酸可挥发性硫化物（AVS）的含量对控制重金属在沉积物/间隙水中的分配和重金属的生物可利用性方面有重要意义，也是海洋养殖业的重要指标之一，研究改正目前《海洋监测规范》中沉积物酸可挥发硫化物的测定方法基础上，建立了一套简单易行的仪器装置和分析程序，讨论了N2流量、反应时间、酸强度、硫总量4个方面对测定结果的影响，给出了胶州湾海区沉积物中AVS的定量数据，表明胶州湾养殖海区沉积物中AVS的含量显著高于非养殖海区和其它海湾沉积物中AVS的定量数据，表明胶州湾养殖海区沉积物中AVS的含量显著高于非养殖海区和其它海湾沉积物中AVS的含量，探讨了应用AVS归一化沉积物中二价有毒金属评价其化学活性和生物可用性的可能性。  相似文献   

晶安高科“三废”治理及综合利用     

罗方承 《矿产与地质》2001,15(Z1):540-547

介绍了晶安高科污染源的来源、采取的措施及综合治理、利用方法.使废水指标由PH11～12;SS<1000mg/l;CODcr≤200mg/l;氨氮≤200mg/l降到PH6～9;SS<70mg/l;CODcr≤100mg/l;氨氮≤15mg/l;酸雾指标由HCl500～800mg/m3达到小于25～40mg/m3;炉窑烟气由林格曼黑度5,烟尘浓度2700～5191mg/Nm3降到林格曼黑度1,烟尘浓度小于200mg/Nm3;硅渣可生产复合絮凝剂和白炭黑,不仅可改善环境影响,而且可回收盐酸和利用废资源,可给企业带来经济效益.  相似文献   

An assessment of acid rock drainage continuous monitoring technology     

K. Fytas  J. Hadjigeorgiou 《Environmental Geology》1995,25(1):36-42

In order to assess the magnitude and impact at affected mine sites of acid rock drainage (ARD), fixed-frequency sampling is often employed. This often involves manual sampling, at regular time intervals, of water and solids. It is felt that such sampling does not adequately describe the system evolution. Continuous monitoring offers a viable alternative in that it can better follow the seasonal fluctuations and high-frequency variations that characterize ARD. This paper evaluates existing continuous monitoring technology.  相似文献   

中国和日本降水化学特性的分析比较   总被引：19，自引：2，他引：19       下载免费PDF全文

黄美元  植田洋匡  刘帅仁 《大气科学》1993,17(1):27-38

本文对中国33个站、日本29个站及美国9个站的降水化学资料进行了分析比较.结果表明,中、日、美三国的降水化学特性有很大不同.三国都有酸雨,但以美国的pH平均值最低.雨水中离子总浓度以中国为最高,其中SO_4~=,NH_4~+和Ca~(++)的浓度特别高.日本雨水中Cl~-和Na~+的浓度很高.NO_3~-在美国雨水中最高.从雨水中离子结构组成和几种重要参量的比值分析表明,中国雨水中的离子浓度受陆地源影响很大,而影响日本雨水中离子浓度最大因素是海洋.在美国以工业交通污染的影响相对最大.文中还对中、日两国不同地区的降水化学特性进行了分析和讨论.  相似文献   

区域酸沉降模式   总被引：5，自引：3，他引：5  

贾新媛 《大气科学》1993,17(6):732-740

本文提出一个区域的欧拉酸雨模式,包括了大气中污染物质的输送、扩散、非线性化学转化和干湿沉降等物理和化学过程.气相化学反应有18种化学物质,包含了二氧化硫气相氧化的主要化学方程.液相氧化反应包含了H_2O_2,O_3及催化剂对二氧化硫的氧化过程.水平方向有35×35个网格点,垂直方向分15层.选用了四川、贵州地区1988年的8次降水过程对模式作了检验,结果证明模式能较好地模拟这个地区的二氧化硫、硫酸根及降水pH的分布状况.  相似文献   

On the scavenging of SO2 by cloud and raindrops: I. A theoretical study of SO2 absorption and desorption for water drops in air     

C. J. Walcek  H. R. Pruppacher 《Journal of Atmospheric Chemistry》1983,1(3):269-289

An extention of our previous theory for trace gas absorption into freely-falling cloud and raindrops is presented. This theory describes the convective diffusion of a trace gas through air and into a water drop with internal circulation, the drop falling at its terminal velocity. Using flow fields for the circulating water inside and for the moving air outside the drop, obtained by numerical solutions to the Navier—Stokes equation of motion, we numerically solved the convective diffusion equation to determine the uptake of SO₂ by water drops of various sizes, time exposure to the gas phase, and concentration of SO₂ in the gas phase. It was found that for drops of radius larger than 1 mm and relatively low gas concentrations (10 ppb (v)), resistance to gas diffusion lies mainly in the gas phase; while for drops of radius less than 500 m and gas concentrations larger than those found in the atmosphere (1% (v)), the resistance to diffusion lies primarily in the liquid phase. With drop sizes and gas concentrations between these limits, the rate of SO₂ uptake is controlled by a coupled resistance to diffusion inside and outside the drop. In addition to our general model, a simplified version was formulated which allows considerable savings in computer time for evaluation and improved ease of handling without significant loss of accuracy. A comparison between our simplified model and that of Barrie (1978) shows that the boundary-layer approach of Barrie may be a useful alternate approach to estimating trace gas absorption by water drops, provided appropriate values are chosen for the thickness of the boundary layers involved.  相似文献