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1.
对采自新疆尉犁蛭石矿的金云母蛭石间层矿物样品进行了酸处理实验研究。在样品化学成分和XRD分析的基础上,研究了样品酸处理后酸浸取物的化学组成、含量及结构变化特征;分析讨论了金云母蛭石间层矿物在酸处理过程中不同阳离子浸出率的变化规律和酸蚀机理。结果表明,层间可交换性阳离子的氧化物CaO和Na2O的酸浸取率最高,层间不可交换性阳离子的氧化物K2O次之,八面体中阳离子的氧化物MgO、Fe2O3和Al2O3具有较高的酸浸取率,而四面体阳离子的氧化物Si O2的酸浸取率最低;金云母蛭石间层矿物中蛭石晶层含量高的样品酸浸取率高,金云母蛭石间层矿物的耐酸蚀性能不如金云母。 相似文献
2.
用红外、拉曼谱学方法探讨了硅藻土表面酸位,并分析了其来源。结果表明,硅藻土表面有限的Lewis酸位来源于矿样中的少量粘土矿物。其表面的Brφnsted酸位也很稀少,这是由于大部分表面羟基是非质子酸性。 相似文献
3.
以稍酸、盐酸、氢氟酸及王水作为溶剂,采用微波消解和电感耦合等离子体方法对钢铁中的砷、铅、锑、锡、铜等微量元素进行测量的方法.实验考查了不同消解酸、温度计时间对对消解效果产生的影响.结果发现在压强为1.52MPa,温度为200℃下,使用3mL盐酸、1mL硝酸及1mL氢氟酸组成的混合液,可以将钢中的As、Pb、Sb、Sn、... 相似文献
4.
Humic acid adsorption onto the bacterial surface of Bacillus subtilis was measured with and without Cd, as a function of pH and humic–bacteria–Cd ratios. These experiments tested for the existence of ternary interactions in a bacteria–humic–metal system. We determine both the effects of humic acid on the bacterial adsorption of Cd, as well as the effects of the aqueous metal cation on the bacterial adsorption of humic acid. The presence of Cd does not affect the extent of humic acid adsorption onto the bacterial surface, indicating that there is no competition for sorption sites between humic acid and Cd under the experimental conditions, and that changes in the charging properties of the bacterial surface, as a result of the Cd adsorption, are not significant enough to affect humic acid adsorption. The presence of humic acid does diminish Cd adsorption onto the bacterial surface, suggesting the presence of an aqueous Cd–humate complex under mid to high pH conditions. However, we also observe that the solubility of humic acid is unaffected by the presence of aqueous Cd. This apparently inconsistent behavior of an aqueous Cd–humate complex affecting Cd adsorption but not affecting humic acid solubility is not observed with simpler ionizable organic molecules. We propose that the solubility of humic acid is controlled by the solubility of a less soluble fraction of the acid. Cd forms an aqueous complex with the more soluble fraction of humic acid and there is no interdependence between the aqueous activities of the more and less soluble fractions. That is, the solubility of one humic acid fraction is unaffected by the presence of an aqueous Cd–humate complex involving another humic acid fraction. These experimental results constrain the relative importance of surface ternary and aqueous metal–humate complexes on the bacterial adsorption of both humic acid and metal cations. 相似文献
5.
The key components of S. triqueter root exudates involved 4-oxo-pentanoic acid, succinic acid, glutaric acid, phthalate acid, citric acid, vanillic acid, myristic acid, pentadecanoic acid, decanoic acid, 14-methyl-pentadecanoic acid, hexadecanoic acid, octadecanoic acid and oleic acid, and the content of the water-soluble organic acids (citric acid, succinic acid and glutaric acid) significantly increased in pyrene and lead co-contaminated rhizosphere soil. These three water-soluble organic acids including citric acid, succinic acid and glutaric acid were detected as the specific root exudates of S. triqueter under stress of pollutants for pyrene and lead, so they were chosen as the research objects, and they were added into the bioremediation systems of pyrene and lead co-contaminated wetland soils. Compared with the control, the treatments added the three organic acids always improved the quantity of the bioavailable fraction of pyrene and lead in wetland soils and greatly influenced other chemical states of pyrene and lead fractions in the test concentration range. Under the 50 g kg ?1 of organic acids concentration, the amount of the bioavailable fraction of pyrene and lead increased 41.0 and 872.7 % by citric acid, respectively. The enhancement of bioavailability of pyrene and lead in the wetland soil by adding organic acids generally decreased in the following order: citric acid > succinic acid > glutaric acid. Enhancing effects of organic acids on the bioavailability improvement of pyrene and lead is remarkable. 相似文献
6.
本文提出以P_(507)为固定相,盐酸为流动相的萃取色谱法把铈从溶液中分离出来,以偶氮氯瞵-mN与铈的高灵敏显色反应进行比色。本法灵敏度ε=7.8×10~4。实验部分色谱柱:φ8×120m/m 硅烷化硅球100—120目(上试一厂出品) P_(507)(上海有机化学所实验工厂) 偶氮氯膦-mN0.05%水溶液杂质洗除液:5%NH_4Cl,2%磺基水杨酸,1%抗坏血酸,调至pH2—3 铈、镧、镨标准液:用光谱纯的氧化铈、氧化镧、氧 相似文献
7.
将样品放入坩埚中用王水溶解,再放入高氯酸,然后在中温电热板加热坩埚至冒高氯酸的白烟,此时硝酸已蒸发掉,趁热加入盐酸将锡还原成低价。用硫脲—抗坏血酸消除铁等过渡金属元素的干扰,用氢化物原子荧光法测定化探样品中的锡。经国家一级标准样品验证,这种方法简便可靠,具有较高的灵敏度和较低的检出限。 相似文献
8.
The experiments on gold solubility in amino acid solution mdicate that gold is very intensively soluble in amino acid(or other organic acids),which is extensively present in geological bodies,and is most soluble in histidine.The temperature and concentration,acidity and type of amino acid in the solution are important factors affecting gold-amino acid complexing. The solubility of gold in amino acid is different under different conditions of temperature, amino acid concentration and pH value of the solution,At 80℃ and pH=6-8,gold is most soluble in amino acid.Gold dispersed in water and rocks could be concentrated and transported by amino acid and then precipitated in favorable loci.Amino acids might have played an important role in metallogenesis as well as in the formation of source beds of gold.Nitrogen,oxygen and sulfur in amino acid might have reacted with gold to form soluble complex ions. 相似文献
9.
57Fe Mössbauer spectra have been obtained from samples of humic acid, fulvic acid and kerogen and from the organic material extracted from bituminous chalk with benzene-methanol. The spectra indicate that iron occurs in a trivalent form in the silicate residue of the humic acid fraction, as hydrated ferrous ions associated with the fulvic acid fraction, as pyrite in kerogen and in a form not detectable by Mössbauer spectroscopy in the benzene-methanol extract. 相似文献
10.
样品经硝酸、氢氟酸分解除硅,加热硫酸冒烟除尽硝酸、氢氟酸,利用铟与氢溴酸能生成稳定的络合物并被乙酸丁酯萃取的性质,将铟与其它干扰离子分离并富集.使用MOLAARM6(Thermo Electron Corporation)石墨炉原子吸收分光光度计,以钒为机体改进剂,测定铅锌矿中的铟.方法检出限为LD=0.012ug/ml.实验结果令人满意. 相似文献
11.
本文论述了一种聚氨酯泡塑预富集—石墨炉原子吸收分光光度法测定土壤样品中痕量铊的方法。样品经盐酸—硝酸—高氯酸—氢氟酸分解后,再加入10%硝酸。在Fe件和过氧化氢介质中,痕量铊被聚氨酯泡塑富集。用蒸馏水在沸水浴中解脱,以抗坏血酸作基体改进剂消除基体影响后,用石墨炉原子吸收分光光度法测定痕量铊。方法检出限为0.2ng/g。用本方法测定土壤国家一级标准物质中痕量铊,结果与推荐值相符,12次检测结果的精密度(RSD)为:5.05%~8.74%。 相似文献
12.
研究水玻璃-碳酸钙注浆材料随着碳酸钙加入量的变化胶凝时间的变化规律发现,随着碳酸钙加入量的减少,溶胶胶凝时间随之增加,但并非均匀增加,当碳酸钙的量减少到一定量时,溶胶的胶凝时间会有一个突增点,溶液对碳酸钙的加入量非常敏感,凝胶时间不易准确控制。这是因为碳酸钙在整个反应体系中充当碱性反应剂,与溶液体系中的H+反应,降低了硫酸的浓度,提高了溶胶的pH值,从而改变了溶胶的胶凝时间。选择胶凝时间适宜的胶体测定其本身的强度以及对应的固砂体强度,得出两种强度的变化规律:在硫酸用量一定的条件下,一般随碳酸钙的增加,纯胶体强度会相应增加,但加入到一定量后,其强度不再增加。而固砂体强度随碳酸钙的变化并不明显。选择较优配比浆液作为新型注浆材料,并根据浆液的性能,建议相应的注浆工艺。为后续工程应用作了较好的铺垫。 相似文献
13.
大量研究表明,溶解性有机质与铁的螯合对生物可利用性铁的输出有重要影响.然而,对于天然有机质,尤其是泥炭沼泽源的酚类物质,与铁相互作用的地球化学机制仍然缺乏研究.以长白山西麓哈尼泥炭沼泽为研究对象,调查了泥炭沼泽源水体可溶性总铁、亚铁、水溶性总酚等理化指标.同时,测定了泥炭中酚酸的组成及含量,分析对比泥炭与土壤中铁的主要赋存形态.并开展了酚铁相互作用模拟实验,研究了泥炭沼泽源水体中酚铁相互作用机制.结果表明:哈尼泥炭沼泽水体中亚铁浓度与水溶性总酚浓度显著相关,说明水溶性总酚对亚铁的存在及运移有重要影响.哈尼泥炭中含有原儿茶酸、咖啡酸、没食子酸、龙胆酸、丁香酸、阿魏酸、对羟基苯甲酸、对香豆酸、水杨酸、香草酸等多种酚酸.其中,具有儿茶酚或没食子酰基结构的原儿茶酸、咖啡酸和没食子酸能与亚铁形成稳定螯合物,是泥炭沼泽源水体中Fe(Ⅱ)保持稳定并可以远距离迁移的关键.研究还表明,原儿茶酸、咖啡酸、没食子酸和龙胆酸对Fe(Ⅲ)有显着的还原作用,有利于沼泽区水体中的保持较高Fe(Ⅲ)和Fe(Ⅱ)浓度.哈尼泥炭中铁主要以活动态(可交换态、络合态和无定形态)为主,为铁的迁移、转化和循环奠定了基础.鉴于泥炭沼泽在全球的分布面积巨大以及亚铁对海洋生物有促进作用,酚酸对铁的作用机制对陆地系统向海洋输送生物可利用铁具有重要意义,并对碳循环、硫循环以及气候变化有重要影响. 相似文献
14.
为了粉煤灰的高附加值综合利用,采用酸浸法对准格尔地区循环流化床粉煤灰进行了镓的浸出实验研究,考察了多种因素对镓的浸出率的影响,包括粉煤灰粒度,酸的种类与浓度、酸浸温度与时间、固液比等。结果表明,提高镓的浸出率的适宜条件为:粉煤灰粒度200目,盐酸的浓度6 mol/L,酸浸温度应大于160℃,酸浸时间6 h,液固比在5∶1~6∶1之间为宜。在优选的工艺条件下,镓的浸出率可达80%以上。从粉煤灰中提取镓,使其作为一种资源加以利用,是提高粉煤灰综合利用价值的有效途径。 相似文献
15.
选取广西的桂林、柳州、河池、百色、玉林、南宁、钦州7个酸雨监测点进行了为期一年(2014年5月至2015年5月)的监测,结合各站点溶蚀试片和降雨降雨量、降雨时间、pH值和电导率等,分析了试片溶蚀量的主要影响因素及酸雨的源汇效应。结果表明,试片溶蚀量与累计降雨时间,即溶蚀作用发生的时间关系密切。单场酸雨对碳酸盐岩的溶蚀过程可分为两个阶段,即:前期强酸溶蚀碳酸盐岩,释放CO2,为碳源;后期碳酸溶蚀碳酸盐岩,吸收大气CO2,为碳汇。而就整年而言,碳汇过程占绝对优势,酸雨减汇量仅占总溶蚀量的0.27%~3.52%,平均为1.96%,但酸雨减汇比例随酸雨pH值的降低而呈指数增加。酸雨对岩溶碳汇有着显著影响,在岩溶碳汇的研究中不应忽视。 相似文献
16.
Modern acid and neutral saline lakes in Western Australia are an excellent natural laboratory for testing how pH affects halite, and for developing criteria for distinguishing past acid saline waters from past neutral saline waters in the rock record. This study characterizes and compares physical, chemical and biological features in halite precipitated from acid (pH 1·7 to 4·2) and neutral (pH 6·8 to 7·3) saline lakes in southern Western Australia. Supplemental data include synthetic halite grown from acid and neutral saline solutions, as well as halite deposited in Permian acid lakes. Although physical processes of halite growth are not affected by pH, there are differences in the colour, accessory minerals, fluid inclusions and microfossils between acid and neutral halites. Acid lake halite commonly is yellow or orange in colour; neutral lake halites examined in this study are always snow white. Acid halites tend to contain abundant sulphate and iron oxide minerals, both as solid inclusions and as solids within fluid inclusions; neutral halites contain little, if any, sulphates and no iron oxides. Acid fluid inclusion freezing/melting behaviours include characteristics that differ from neutral fluid inclusion behaviours, such as lower eutectic temperatures, higher and wider temperature range of hydrohalite rims with a definable fuzzy border and more complex metastable phases. Acid halite contains 'hairy blobs', clusters of bacterial/archaeal/fungal remains and sulphate crystals, which are not found in halite from neutral lakes. This distinct assemblage of features characteristic of modern acid lake halites may serve as informal criteria for the recognition of past acid lake evaporites in the rock record. 相似文献
17.
在综述国内外酸雨研究基础上,提出了我国酸雨研究中存在的一些问题。我国在酸雨研究方面已经取得了重大的进展,许多研究成果被有效地应用于酸雨的控制,但由于酸雨的不断加重和酸雨问题的复杂性,许多问题还需要深入研究,如:①随着能源结构的不断变化,研究建立适合我国特点的酸雨预测模型;②从生态系统角度研究酸沉降及其酸沉降破坏的生态系统的恢复技术;③研究燃煤二氧化硫的控制和不同行业如化工、建材、冶金等工艺废气的脱硫技术;④研究与我国的经济发展水平相适应的、合理的酸雨控制对策;⑤将新技术与酸沉降研究有机结合起来,研究基于GIS的酸化模型,规划酸沉降临界负荷。 相似文献
18.
针对有机质对疏浚淤泥固化处理效果产生的影响,研究有机质的主要成分腐殖酸对水泥固化的影响。研究表明,腐殖酸对水泥的水化具有抑制作用,腐殖酸含量对淤泥固化土的无侧限抗压强度和破坏应变的影响存在一个极限含量(3.62 %),超过这一极限含量,随腐殖酸含量的增加固化土的强度和破坏应变几乎不再变化。同时,研究结果表明,随着腐殖酸含量的增加,固化土塑性增强。 相似文献
19.
The chemical weathering can consume atmosphere/soil CO2. Human activities such as pollution, fertilization and acid precipitation have exerted a large impact on CO2 intake by carbonate weathering. Thus, based on the analysis on chemical component change of the karst groundwater in the karst ridge watershed of Conglin Village, Fuling District of Chongqing City, the influence of human activities such as fertilization, sewage discharges from mustard tuber processing, breeding industry and acid rain precipitation on carbonate weathering and CO2 intake in 1980, 2003 and 2006 was studied. The results showed that CO2 intake by carbonate rock declined with year. Because H+ derived from acid sewage discharge, fertilization and acid precipitation reacted with carbonate rock when mustard tuber production and swine breeding were developed fleetly after 2000 as well as the burning amount of high-sulfur coal augmented persistently, which led to the increase of (Ca2++Mg2+)/HCO3-. The difference on charge between Ca2++Mg2+ and HCO3- was balanced by NO3-+SO42-. The control on pollution and acid rain, especially the pre-neutralization of acid waste water, would rejuvenate the atmospheric CO2 intake strength of carbonate weathering besides the protection of water and soil environment 相似文献
20.
通过对一些矿物纤维粉尘耐酸蚀性及其酸蚀残余物化学活性的测试分析和对矿物纤维粉尘的酸蚀历程尤其在酸蚀过程中其表面活性基团的变化及影响耐酸蚀性及其化学活性的诸多因素的较深入的探讨,并结合作者以前和前人的研究成果,探讨了矿物纤维粉尘耐酸蚀性强弱及酸蚀过程澡表面活性基团变化与生物活性大小变化的关系。结果表明,矿物纤维粉尘的酸蚀持久性与其晶体结构、结晶度、晶格缺陷多少有关,也与其表面官能团种类、位置及裸露程 相似文献
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