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密云水库沉积物-水界面磷的地球化学作用 总被引:11,自引:4,他引:11
以密云水库为例,研究了水库沉积物中有机质的含量与有机磷的关系,表明表层沉积物中的总有机碳和有机磷的含量都明显高于底层,是由于一些以磷为营养素的富营养化指示藻类在水体中逐年增加,它们死亡后的残骸经分解-矿化后在底积物中累积的结果。沉积物和孔隙水中磷的剖面特征研究表明,表层沉积物和孔隙水中的磷都有明显上升的趋势,是由于沉积物的表层微生物和活性有机碎屑层比较丰富,有机质降解和含磷的有机化合物分解,使溶解性磷酸盐进入孔隙水。对沉积物磷形态、总有机碳及孔隙水中总磷对磷释放的影响进行了线性相关分析,结果表明上覆水中的磷主要来自沉积物的铁结合态磷、铝结合态磷、溶解态磷三种形态,孔隙水中总磷以及总有机碳含量对上覆水中总溶解磷浓度存在较大的影响,这些为研究水库沉积物作为水库内污染源对水质的影响提供了基础资料。 相似文献
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偏最小二乘法回归 (PLS)研究酸性森林土壤中铝的释放过程 总被引:6,自引:1,他引:5
采集了华南和西南酸性森林小流域中的土壤和土壤水并分析其化学组成,利用偏最小二乘法回归(PLS)研究了土壤中铝的释放过程,以综合评价各种影响因素的相对重要性。连续3年(2000~2002)的现场监测数据表明,尽管土壤水中铝的浓度存在显著差异,但铝的形态分布在各流域之间基本相似。大多数土壤水中单体铝(Ala)主要以无机态(Ali)存在,有机铝(Alo)一般不足10%。在pH3.6~5.6范围内,土壤水中Al3 活度(pAl)与土壤水pH值呈显著正相关关系(P<0.001),上层和下层土壤中pH-pAl拟合直线的斜率分别为1.28和2.00,明显偏离三水铝石(gibbsite)的溶解平衡模式。偏最小二乘法回归分析显示,上层和下层土壤中铝具有不同的来源和主导影响因素。上层土壤中,铝主要来源于有机键合铝(Alorg),土壤水离子强度(I)是造成铝浓度差异的主导因素。与此同时,铝的释放过程明显受到离子交换反应的影响。下层土壤中,铝近乎全部来源于无机键合铝(Alinorg),土壤水H 浓度成为影响铝释放过程的最主要因素。与上层土壤相比,离子交换对土壤铝释放过程影响明显减小。 相似文献
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沉水植物黑藻对上覆水中各形态磷浓度的影响 总被引:18,自引:2,他引:16
室内模拟研究了沉水植物黑藻对上覆水中不同形态磷浓度的影响及其季节性变化,并从沉水植物生长、间隙水和碱性磷酸酶活性(APA)三方面进行了讨论,进一步揭示磷在浅水湖泊水-沉积物界面的交换机理。结果表明,在本研究条件下,上覆水中各形态磷以溶解性总磷(DTP)为主,其他形态磷浓度变异较大,黑藻降低了上覆水中总磷(TP)、溶解性活性磷(SRP)和DTP浓度,也降低了DTP和SRP占总磷的比例,从而使颗粒态总磷(PP)和溶解性有机磷(DOP)占总磷比例升高。黑藻主要通过吸收上覆水中的磷和抑止沉积物、上覆水中APA使上覆水中各形态磷浓度保持较低水平,其中对SRP和DTP浓度的影响更明显。上覆水中各形态磷浓度呈现明显的季节性变化。在7~8月,TP、SRP和DTP浓度呈下降趋势,并在8月达到最低值;9~10月间有所升高,但仍然维持在较低水平,不同采样时间存在波动。 相似文献
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新型混凝剂处理印染废水的实验研究 总被引:5,自引:0,他引:5
采用自行制各的具有不同SiO2:Al:Fe(摩尔比值)和碱化度的两类新型无机高分子混凝剂聚硅酸氯化铝铁(PSAFC)和聚硅酸硫酸铝铁(PSAFS)各7种,直接对印染废水进行处理。从中选出2种温凝剂,考察了pH值、混凝剂投量等对混凝效果的影响,并对混凝处理后,印染废水出水中残留温凝剂主要成分Al、Fe、SiO2的含量进行分析。实验结果表明,氯化物型(PSAFC)和硫酸盐型(PSAFS)混凝剂对印染废水的色度、浊度、COD Cr均有良好的去除效果;总体而言,PSAFS的混凝效果略优于PSAFC;混凝处理后印染废水出水中残留铝、铁、硅的含量均比较低;pH值和碱化度对温凝剂在水体中残留铝含量有影响。 相似文献
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根据法拉第电解定律,利用电化学原理自制了净水器,并进行了工作参数的选择,净水器的电生铝离子用来沉淀和分离水中超标的氟离子,以此除去高氟水中的氟化物,得到符合卫生标准的生活饮用水。应用该装置对9.0mg/L的高氟水进行处理,可以达到1.0mg/L的饮用水。 相似文献
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聚硅氯化铝铁(PSAFC)絮凝剂的形态分析 总被引:5,自引:0,他引:5
通过对聚硅氯化铝铁水解共聚物的合成制备及水解共聚过程PH变化的研究,对铝铁共物的化学形态、二氧化硅的加入和碱化度B对铝铁共聚物的影响进行了研究和讨论;并应用Ferron配合逐时比色法对聚合物中铁的形态进行了表征,为深入研究聚硅氯化铝铁铁奠定了理论基础。 相似文献
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卢治平 《华东地质学院学报》1995,18(2):179-184
本文根据发生硅钼黄反应的条件,将天然水中硅酸分为三种形态:α-硅酸、β-硅酸和γ-硅酸,并提出了用硅钼黄和硅钼兰测定水中三种相应形态硅酸的分光光度测定法。 相似文献
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为了研究煤炭固体废弃物中铝的含量及赋存状态,探讨其中氧化铝提取的可能性,在处理煤炭固体废弃物的同时扩大我国自然铝资源,分别采用化学分析、XRD、SEM及粒度分布等方法对鄂尔多斯北缘准格尔等煤田煤矸石及粉煤灰进行了化学成分、物相组成及结构测定。结果表明:该地区的煤矸石和粉煤灰中氧化铝的质量分数均接近或大于40%, 达到了铝矿床的工业品位;煤矸石中铝主要赋存在高岭石和勃姆石中,OF灰中铝主要赋存在莫来石中,而CFB灰中铝则赋存在非晶态物质中;同时CFB灰与OF灰相比具颗粒细小且粒度分布均匀、颗粒形态呈絮状、结构活性高等特点;CFB灰中的铝活性高易提取,煤矸石中的铝只需要热活化即可提取,而OF灰中的铝则需要化学活化才可以提取。高铝煤炭固体废弃物中铝的有效提取可以补充铝资源的不足。 相似文献
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利用铝型材厂碱蚀渣为主要原料,采用二步煅烧工艺制备铝方柱石材料。探索二次煅烧温度对铝型材厂碱蚀渣制备铝方柱石材料相组成、结晶度、微观结构的影响,进而研究氧化铬对铝方柱石材料相组成、微观结构的影响。采用同步热分析、X射线衍射、扫描电镜及相关分析软件表征制备的铝方柱石材料的相组成和显微结构。结果表明:铝型材厂碱蚀渣中有大量可烧失成分,物料需要进行致密化处理,再经过1500℃煅烧后的铝方柱石材料结构中具有明显的铝方柱石条柱状结构,结晶度增大,铝方柱石相对含量达到91%。随着氧化铬加入量增加,结构中的铝铬酸钙相增加。当氧化铬加入量为2%时,试样中结晶相的结晶度最高,形成条柱状铝方柱石相与立方状铝铬酸钙相共存的结构。当氧化铬加入量4%时,试样中铝方柱石相几乎消失,结晶度降低。 相似文献
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钙、铁、铝形态对岩溶石灰土磷有效性的影响 总被引:2,自引:1,他引:1
为揭示钙、铁、铝形态与岩溶地区土壤磷有效性关系,通过改进的BCR元素形态连续提取法获取石灰土不同发育阶段土壤矿质元素赋存形态,并分析与总磷及速效磷含量之间的相关关系。初步研究表明:石灰土壤中全磷和速效磷在石灰土发育过程呈降低趋势,从黑色石灰土到黄色石灰土,总磷降低了76.7%,速效磷减少了84.7%。石灰土总磷与速效磷同酸溶态、可还原态及残渣态钙,可氧化态铁、铝和可还原态铝显著正相关,而同总铁、总铝以及残渣态铝显著负相关,相关系数绝对值均达到0.9以上。随着石灰土发育进行,钙总量及其形态均降低,而铝、铁总量和形态呈增加趋势,可能导致岩溶地区石灰土磷及其有效性缺乏越发突出。 相似文献
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铬天青S光度法是硅中铝含量的测定方法之一,该方法的标准曲线大多采用不过零点的线性拟合,导致低铝含量测定误差大。为提高方法准确度并降低方法检出限,研究了铝标准曲线低浓度部分的拟合问题,探讨了不同拟合模型对检测结果准确度的影响。实验结果表明,不同浓度铝标准液的吸光度在0~0.3 μg/mL范围内并不满足一次函数线性关系,采用三次函数关系y=-17.45230x3+10.42883x2+1.04047x (y为扣空白的吸光度,x为铝的质量浓度)拟合能获得良好结果,其相关系数R2为0.99975。利用已知铝含量的硅试液检验该公式,其相对标准偏差(RSD)为2.55%。样品中铝的测定值与电感耦合等离子体发射光谱法测定值吻合。该法可以显著提高低浓度的铝测定的准确性,可用于测定高纯硅中含量在0.55 μg/g以上的铝杂质。 相似文献
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The paper presents study results obtained for the bottom sediment samples of fjords Kongsfjord, Isfjord, Hornsund in the form of surface samples and their core profiles. The concentrations of labile form of aluminum and heavy metals were determined using the single-stage extraction with 3 mol L?1 HCl. The obtained results allowed defining the occurrence of variability of labile aluminum form in the samples of bottom sediments of the studied fjords depending on the point and depth of sample collection. The conducted chemometric analysis allowed for the study of spatial variability of aluminum occurrence in the area of the investigated fjords. Based on the analysis, the correlations between aluminum and heavy metals were determined. 相似文献
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《International Geology Review》2012,54(3):526-539
The relation between aluminum and titanium in the course of bauxite formation is one of the key problems in deciphering the genesis of bauxitic rocks, particularly those occurring in geosynclinal areas. The source of aluminum and titanium in marine geosynclinal bauxites is related directly to the effects of volcanism. Ultra-acidic thermal waters may extensively leach volcanic rocks, resulting in the removal and migration of large amounts of aluminum in solution. These solutions are extremely stable, even when diluted by surface waters, and move to the sea without losing aluminum by precipitation. Primary titanium minerals are also decomposed and displaced in hydrothermally-altered rocks. Titanium is removed primarily as colloidal titanium hydroxide. Aluminum in solution and titanium in the form of colloidal titanium hydroxide films are carried to the sea in acid streams. As the acid streams are neutralized upon mixing with sea water, aluminum forms an amorphous colloidal hydroxide that coagulates and crystallizes. Titanium is extracted by its co-precipitation with aluminum hydroxide by a sorption mechanism. The migration and co-precipitation of these elements in the manner outlined is believed to be responsible for the formation of geosynclinal bauxite deposits in volcanic areas of island arcs. — R.D. DeRudder. 相似文献
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S. N. Jamal M. Z. Iqbal M. Athar 《International Journal of Environmental Science and Technology》2006,3(4):411-416
A greenhouse experiment was conducted to determine the phytotoxic effect of aluminum and chromium on the germination and early growth of two wheat (Triticum aestivum) varieties Anmol and Kiran. Seed were treated with 40, 80, 120 and 160 ppm of aluminum and chromium solution individually and in combined form. Observations were made on seed germination, root, shoot and seedling length, and dry biomass. Seed germination and dry biomass showed no effect of aluminum, chromium and combined treatment. Root, shoot and seedling length of both the varieties showed significant (P<0.05) decrease as compared to control. The growth was also reduced as the concentration of aluminum and chromium increased. Seedling length decreased in both the varieties at all the concentration of different treatment of aluminum, chromium and combined treatment. Attempts are being made in different laboratories to construct novel plants using genetic manipulation technologies that may have a greater tolerance to the presence of toxic metals. The results of the present study may help in understanding the mechanisms involved and their possible use in pytoremediation. 相似文献
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Sh. N. Jamal B.Sc. M.Sc. M. Z. Iqbal B.Sc. M.Sc. Ph.D. M. Athar M.Sc. M.Phil. Ph.D. D.Sc. 《International Journal of Environmental Science and Technology》2006,3(2):173-176
Prosopis seeds were grown under controlled environment in solution of aluminum and chromium at different concentration alone as well as combined together. The effect of these metals was studied on seed germination, root length, shoot length, seedling length and dry biomass. Aluminum and chromium alone, and combined together showed no effects on germination and dry biomass. Chromium alone was found toxic to root, shoot and seedling length. However, application of different concentrations of aluminum increased the root, shoot and seedling growth. It may be concluded that aluminum is not as toxic as chromium, and their combined treatment showed the intermediate effect by ameliorating the impact of one another. 相似文献