丢状氢氧化镁铝对偶氮染料酸性黑10B的脱色性能研究

分别用层状氢氧化镁铝（LDH）和焙烧层状氢氧化镁铝（CLDH）作为吸附剂吸附脱除水溶液中偶氮染料酸性黑10B。考察了脱色时间、pH值、吸附剂的投加量、温度、染料初始浓度和焙烧温度等因素对脱色率的影响。结果表明，LDH及CLDH对酸性黑10B染料具有良好的脱除效果，室温下，10g／L LDH和1g／L的CLDH对浓度为100mg／L的染料的脱色率分别达95．93％和99．97％。pH值是影响吸附能力的关键因素，吸附剂对溶液pH值有一定缓冲作用。LDH及CLDH对酸性黑10B吸附结果符合Langmuir吸附等温式。饱和吸附后的LDH及CLDH用高温热解法再生，吸附性能良好，随再生次数增多，脱色率下降。     

新型絮凝剂聚合氯化铝钙中铝形态表征及钙含量测定

以Al2O3和CaCO3为原料经高温焙烧酸溶制备工艺合成新型高效絮凝剂——聚合氯化铝钙。采用Al-Ferron逐时络和比色法研究产品中的铝形态;络合滴定法研究钙含量。结果表明:焙烧工艺对钙含量的影响较大,酸溶工艺对钙含量的影响较小。在最佳配比条件下,生成的Alb为最佳;焙烧温度提高Ala、Alc含量减小,Alb含量增大;增长酸溶反应时间Alb含量减少;增加酸用量,Ala、Alc含量减少,Alb含量增大。     

Effects of Al doping on the structure and properties of goethite and its adsorption behavior towards phosphate

Al substitution in goethite is common in soils, and has strong influence on the structure and physicochemical properties of goethite. In this research, a series of Al-doped goethites were synthesized, and characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The adsorption behavior of these samples towards PO₄^3 − was also investigated. Characterization results demonstrated that increasing Al content in goethite led to a reduction in crystallinity, increase in specific surface area (SSA), and morphology change from needle-like to granular. Rietveld structure refinement revealed that the lattice parameter a remained almost constant and b slightly decreased, but c was significantly reduced, and the calculated crystal density increased. EXAFS analysis demonstrated that the Fe(Al)–O distance in the structure of the doped goethites was almost the same, but the Fe–Fe(Al) distance decreased with increasing Al content. Surface analysis showed that, with increasing Al content, the content of OH groups on the mineral surface increased. The adsorption of phosphate per unit mass of Al-doped goethite increased, while adsorption per unit area decreased owing to the decrease of the relative proportion of (110) facets in the total surface area of the minerals. The results of this research facilitate better understanding of the effect of Al substitution on the structure and properties of goethite and the cycling of phosphate in the environment.     

Aluminium: The Need for a Re-Evaluation of Its Toxicity and Solubility in Mature Forest Stands

Aluminium (Al) is a key element in critical loadcalculations for forest. Here, we argue for re-evaluating theimportance of Al. Effects of two levels of enhanced Alconcentrations and lowered Ca:Al ratios in the soil solutionin a field manipulation experiment in a mature spruce stand(1996–1999) on tree vitality parameters were tested. Inaddition, Al solubility controls were tested. Various loads ofAl were added to forest plots by means of an irrigationsystem. Potentially toxic Al concentrations and criticalratios of Ca to inorganic Al were established. The ratio of Cato total Al was not a suitable indicator for unfavourableconditions for plant growth. No significant effects on crowncondition, tree growth and fine root production were observedafter three years of treatment. In 1999, foliar Mg content inthe highest Al addition treatment had declined significantly.This agreed with the known response to Al stress of seedlingsin nutrient solution experiments. No support was found forusing the chemical criterion Ca:Al ratio in soil solution,foliar and root tissue as an indicator for forest damage dueto acidification. Al solubility was considerably lower thanimplied by the assumption of equilibrium with gibbsite,particularly in the root zone. The gibbsite equilibrium iscommonly used in critical load models. Substitution of thegibbsite equilibrium with an Al-organic matter complexationmodel to describe Al solubility in soil water may have largeconsequences for calculation of critical loads. The resultsindicate that critical load maps for forests should bereconsidered.     

模拟酸雨及其活化Al~（3＋）构成的复合污染对中小型土壤动物的毒杀效果

酸雨可引起土壤中铝离子的活化而造成铝毒问题,因此酸雨及其活化的金属铝离子势必造成对土壤中小型动物的复合污染与影响。为此,通过室内模拟试验,研究3种优势土壤动物直接暴露在4种不同酸度的模拟酸雨和4种不同铝离子浓度梯度组合而构成的复合污染处理条件下的死亡率,以探明酸雨通过降低土壤酸度同时活化Al3＋对土壤动物的叠加影响效应。研究结果表明：弹尾目、线虫、蜱螨目等土壤动物直接暴露在酸水和铝离子的复合溶液中,其死亡率总体上均会随着酸水pH值的降低和Al3＋离子浓度的升高而增加。通过单因素和双因素方差分析还发现,不同类群的土壤动物对模拟酸雨pH和溶液中Al3＋含量的敏感性各不相同,其中酸水和铝离子复合胁迫对线虫和蜱螨目动物死亡率的影响并没有表现出明显的交互作用,但对弹尾目土壤动物死亡率存在显著的交互作用影响。     

烧结法提取沸腾炉渣中的铝和铁

近年来,热电厂和钢厂产生了大量的沸腾炉渣.这些炉渣不仅占用了大量的土地,还污染了土壤、地下水和大气.由于该沸腾炉渣中氧化铝的含量很高,因此,评估其氧化铝提取的可利用性是必要的.本文对内蒙古包头钢铁厂的沸腾炉渣进行了粒径分布试验和化学成分分析试验.X-荧光分析显示,该炉渣中SiO2含量为42.60%,Al2O3含量为32.60%,Fe2O3含量为2.43%,CaO含量为2.16%,K2O含量为0.74%,MgO含量为0.44%,Na2O含量为0.16%,TiO2含量为0.88%,还有一些其他痕量元素.将沸腾炉渣和石灰及精煤混合制成小球,然后在约1 000 ℃下烧结.取不同烧结时间的样品,用硫酸浸取,得到含铝离子和铁离子的溶液.试验结果表明,使用浓度为4 mol·L-1的硫酸,在80 ℃下浸取烧结球样品(质量比为50%沸腾炉渣:40%精煤:10%石灰),24 h可以得到铝和铁的最大提取率,分别为86.50%和94.60%.滤渣可以作为固化材料用于高速公路的路基建设或水泥生产中的添加剂.     

某型飞机防护体系性能优选试验研究

目的采用盐雾对比试验,优选获得抗腐蚀性能优异的防护体系。方法选用飞机常用的两种结构材料(2024、30Cr Mn Si A)的几种备选防护体系,开展盐雾加速腐蚀试验。结果铝合金试件经过10个周期盐雾加速腐蚀试验,涂层鼓泡失效,基体未发生腐蚀;经过7个周期加速腐蚀试验,结构钢试件预制划痕处涂层剥落、基体腐蚀。结论铝合金外部防护体系B方案(铬酸阳极化+37底漆+E面漆)和内部防护体系H方案(铬酸阳极化+TB06底漆)最佳,结构钢推荐选用GE方案(镀镉+钝化+TB06底漆+TS96面漆)。     

铝合金管缩为长锥管金属沿轴向延伸和壁厚变化规律的研究

对铝合金管在无芯棒情况下,缩为内锥为2.5°左右长锥管的金属沿轴向延伸率和壁厚变化规律进行研究,提出了相应的计算公式,可做为确定管坯长度和模具型腔尺寸的依据.     

宇宙成因核素26Al/10Be约束贵州涟江流域沉积物埋藏历史

贵州喀斯特地区位于青藏高原向丘陵地貌转换过渡带,区内发育多级层状地貌面,是研究区域构造-气候-剥蚀耦合作用的天然实验场。本文测定了贵州省惠水县境内涟江I级阶地沉积物中原位宇宙成因核素¹⁰Be和²⁶Al浓度,通过暴露-埋藏模型对沉积物埋藏历史和物源进行研究。与前人研究结果相比,涟江流域单核素剥蚀速率（¹⁰Be平均剥蚀速率为10.85±0.97 m/Ma）显著低于贵州高原其他流域。结合双核素暴露-埋藏模型,研究结果表明更新世以来沉积物样品可能经历了复杂暴露-埋藏-再暴露过程,其物源可能是异地埋藏或洞穴堆积等非稳态剥蚀区。宇宙成因核素对²⁶Al-¹⁰Be联用能有效判别非稳态剥蚀过程,弥补了单核素不能表征沉积物埋藏历史的不足。     

Promoting effect of Zr on the catalytic combustion of methane over Pd/γ-Al2O3 catalyst

The effect of Zr on the catalytic performance of Pd/y-A1203 for the methane combustion was investigated. The results show that the addition of Zr can improve the activity and stability of Pd/γ-Al2O3 catalyst, which, based on the catalyst characterization （N2 adsorption, XRD, CO- Chemisorption, XPS, CHa-TPR and O2-TPO）, is ascribed to the interaction between Pd and Zr. The active phase of methane combustion over supported palladium catalyst is the Pd^0/Pd^2＋ mixture. Zr addition inhibits Pd aggregation and enhances the redox properties of active phase Pd^0/ Pd^2＋. H2 reduction could effectively reduce the oxidation degree of Pd species and regenerate the active sites （Pd^0/ pd^2＋）.