Total Aluminum Concentration Research Articles

Sensitivity of Blacknose Dace (Rhinichthys Atratulus) to Moderate Acidification Events in Shenandoah National Park, U.S.A.

Shenandoah National Park (SNP) receives more acid deposition than any other national park in the United States of America. As part of an effort to assess the impact of acidification upon fish in the park, in situ sub-lethal stress bioassays (measured by monitoring hematocrit) were conducted with acid sensitive blacknose dace Rhinichthys atratulus. Study streams experienced moderate acidification events that resulted in reduced pH (the largest reductionbeing 6.18 to 5.37) and increased total monomeric aluminum (TMA) concentration (the largest being 15 to 39 μg L-1). Although some of these acidification events were within the pH and TMA range expected to result in blacknose dace stress, none was detected by monitoring hematocrit. In an acid-sensitive stream, mean baseflow (pre-event) hematocrit ± SD, was 33.5±4.5%, and hematocrit during the largest event was 31.5±4.9%, A moderate acidification event also occurred in a less acid sensitive stream; pH dropped from 7.18 to 6.38 but TMA remained below 10 μg L-1. Mean hematocrit during baseflowin this stream was 32.3±2.8%, and hematocrit during event flow was 34.1±5.0%. At the time of this bioassay, acidificationevents that would result in acute toxicity for most species of fish did not occur, however the conditions documented in this investigation do not represent the most acute acidification events that have been observed in SNP. It should be noted that a chronic sub-lethal stress, measured by condition indices, has been observed among blacknose dace in SNP streams.

Simulation of flow in a continuous galvanizing bath: Part II. Transient aluminum distribution resulting from ingot addition

The coupled phenomena of momentum, heat, and mass transfer were simulated in order to predict and to better understand the generation and movement of intermetallic dross particles within certain regions of a typical galvanizing bath. Solutions for the temperature and aluminum concentration can be correlated with the solubility limits of aluminum (Al) and iron (Fe) to determine the amount of precipitated aluminum in the form of Fe2Al5 top dross. Software developed by the Industrial Materials Institute of the National Research Council of Canada (IMI-NRC), including k-ε turbulence modeling for heat and mass transfer, was adapted for the simulation of a sequence of operating parameters. Each case was modeled over a period of 1 hour, taking into account an ingot-melting period followed by a nonmelting period. The presence of an ingot significantly changes the temperature distribution and also results in important variations in the local aluminum concentration, since the makeup ingot has a higher aluminum concentration. The simulation showed that during the ingot melting, the total aluminum concentration is higher at the ingot side of the bath than at the strip exit side. The region below the ingot presents the highest aluminum concentration, whereas lower aluminum concentrations were found in the region above the sink roll, between the strip and the free surface. It was shown that precipitates form near the ingot surface because this region is surrounded by a solution at 420 °C, which is lower than the average bath temperature of 460 °C. When no ingot is present, the total aluminum concentration becomes much more uniform and decreases with time at a constant rate, depending on the coating thickness. This information is of major significance in the prediction of the formation of dross particles, which can cause defects on the coated product.

Optimum conditions for Al 13 polymer formation in PACl preparation by electrolysis process

This paper introduces a new and effective method for preparation of PACl-electrolysis process. A series of PACl with high content of Al 13 polymer was successfully prepared by electrolysis process. The amount of Al 13 polymer formed in electrolysis process was found to be highly influenced by current density ( d i ), the distance between the electrodes, electrolysis time and the stirring rate of the electrolyte. For the Al T (total aluminum concentration) of 2.0 M PACl obtained by electrolysis process, the optimal d i and distance between the electrodes were 1.1 A dm −2 and 10 mm respectively. The optimum circulating rate was 5.5 l h −1. Because of the inhomogeneous pH between the surface of cathode and the bulk solution, the electrolysis process has the advantage to form more Al(OH) 4 − as precursor of Al 13 polymer. At the optimum condition, Al 13 polymer accounted for above 70% of Al T (PACl of Al T=2.0 M and B=2.0), which was much higher than that of PACl prepared by other method.

Comparison of Two Wet Digestion Procedures for Multi‐element Analysis of Plant Samples

Two microwave digestion systems for multi‐element analysis of leaves and fruits were compared. Samples were digested by two different methods: 1) with HNO3 (8 mL) and HClO4 (6 mL) using an open microwave system and 2) with HNO3 (5 mL) and H2O2 (3 mL) in a closed microwave system. Total concentrations of aluminum (Al), cadmium (Cd), copper (Cu), chromium (Cr), iron (Fe), leaf (Pb), magnesium (Mg), manganese (Mn), nickel (Ni), and zinc (Zn) were determined in 22 samples by inductively coupled plasma atomic emission spectrometry and by simultaneous inductively coupled plasma mass spectrometry (ICP/AES and ICP/MS). Not statistical differences for Cu, Mn, Mg, Pb, and Zn concentration between the two methods were observed. Trace elements, whose concentration is low, such as Cr and Cd, have to be determinate by ICP/MS. The accuracy of the procedures was acceptable, except for Al, Fe, and Mg using the open microwave system, as the results from certified reference materials were in agreement with certified values.

Development of an on-line electrochemical analyser for trace level aluminium

An in-house designed computerised flow injection (FI) system for low-level aluminium analysis is examined. A simple, low cost electrochemical detection system has been implemented with computerised control and data acquisition system. The system consists of a commercial electrochemical analyser, FI components (manifold, pumps and valves) and an in-house designed control system to perform automated analysis. This system was developed to study aluminium speciation in water, particularly for drinking water. The analytical technique was based upon the complexation reaction between aluminium and a ligand—DASA (1,2-dihydroxy-anthraquinone-3-sulphonic acid). ‘Labile’ and total aluminium concentrations, Al labile and Al total, respectively, were determined by measuring the sample before and after UV irradiation by amperometry at +0.6 V. The limit of detection for this technique was 10 μg/l (0.37 μM) and the linear calibration range was up to 1.6 mg/l (60 μM) with r 2 value of 0.999. The Al labile/Al total ratios of the water treated by 40, 80 and 100 mg/l of alum using a laboratory scale pilot plant to simulate conventional drinking water treatment processes were found to be 0.4, 0.5 and 0.8, respectively. These results indicated that when higher alum dose was employed, the residual aluminium was present mostly as the ‘labile’ species. Whereas, if the treatment process was not running at its optimum condition (underdosing), a large portion of aluminium was present as natural organic matter (NOM)—aluminium complexes in the treated water. The system offers a practical and effective means of providing extended knowledge of residual aluminium in drinking water.

Study of aluminium concentration and speciation of surface water in four catchments in the Limousin region (France)

This study highlights the contamination of the upstream catchment of several rivers (Vienne, Gartempe, Vézère) in the Limousin (France) by aluminium in the absence of atmospheric pollution. The presence of acid soils on a granitic platform is a natural factor which contributes to the presence of protons and aluminium in water. In the Limousin, it seems that the presence of aluminium in surface water is due to a combination of natural factors: poor acid soils, numerous wet moors and peat bogs. It is currently difficult to evaluate the real impact of intensive cultivation of coniferous trees on the aluminium concentrations found in water in this area. In water, the concentration in total aluminium increases with a decrease in pH and an increase in organic matter. Despite, high concentrations of total aluminium at low pH (close to or lower than 6), the monomeric toxic forms of aluminium, computed with a speciation software, are always inferior to the toxic values for fish. Under such conditions, the concentration in aluminium recorded in some upstream catchments of the Limousin rivers may not cause damage to aquatic life.

Influence of aluminum doping on titania pigment structural and dispersion properties

The influence of aluminum concentration on the structural properties and rheological behavior of aqueous suspensions of aluminum-doped titania pigment from the chloride process was investigated. The variation in rheological properties correlates with the change in the pigment surface properties, determined from electrophoresis measurements and atomic surface concentrations. Pigment suspensions exhibited a maximum yield stress and viscosity at or near the isoelectric point (iep). The pH of the maximum yield value of the pigment suspension increases with increasing aluminum hydroxyl group density at the particle surface. For pigments with a high aluminum surface concentration, at pH values where the magnitude of the zeta potential was high, a low-viscosity, dispersed suspension was obtained. The pigment with the lowest aluminum concentration, however, retained high yield stresses over a large pH range even when the zeta potential was of considerable magnitude. Pigment particle interactions are chiefly dictated by van der Waals forces and electrostatic repulsive forces, likely to be influenced by heteroaggregation. The aggregate strength would therefore depend upon the proportion and distribution of aluminum and titanium surface groups of the heterogeneous pigment, which will influence both the Hamaker constant and the degree of heteroaggregation. Overall, very small additions to the total aluminum concentration translate to significant aluminum surface concentration disparities and subsequently to large particle interaction differences.

Determination of total aluminum concentration in soil solution using capillary electrophoresis

Determination of aluminum ion (Al3+) as total aluminum (Al) was performed using on-line pre concentration (field-amplified sample stacking) with a long sample injection time of 180 s in capillary electrophoresis (CE). A linear calibration curve of the Al concentration was obtained, ranging from 10 to 2,000 µg L −1, with a wide range and good determination coefficient of 0.999. This study suggests that the minimum detectable Al concentration can be increased 12 times and that this method is sensitive enough for soil solution analysis, compared with the results obtained by Gottlein and Blasek (Soil Sci., 161, 705–715, 1996). Determination method of total Al concentration in the soil solution was proposed using CE in this study. Soil solution sample collected from Andosols and buffer solution (p-methylaminophenol sulfate (metol)) were adjusted to pH 2.3 and 3.0, respectively, by the addition of HNO3 as a pretreatment for the determination of the total Al concentration. A capillary 40 cm in length × 75 µm in inner diameter was used in order to determine the total Al concentration and shorten the electrophoresis time. This method provides certain advantages such as a very small total sample volume requirement (< 100 µL) and rapid analysis in soil solutions.

Effect of impurities in phosphoric acid on the granulometery of the produced DAP(Di-ammonium PHOSPHATE) in petrochemical plants

The influence of impurities in phosphoric acid on the granulometery of the produced DAP was experimentally investigated in a petrochemical plant. It was found that DAP granulometery can be substantially improved as the total concentration of aluminum and iron oxides in the phosphoric acid is increased up to 2.2±0.1 wt%. A correlation was proposed for predicting the DAP granulometery in terms of total concentrations percent of (Al2O3+Fe2O3) in the phosphoric acid.

Electrode reactions in dc electroslag remelting of steel rod

The non-metallic inclusion content increased significantly when a steel rod of Fe-Ni was remelted by dc electroslag remelting. The silicon content increased slightly. The manganese and sulphur contents did not change. The total aluminium content in the ingot was max. 0·7%, while that in the electrode was only 10 ppm. The aluminium cations Al3+ in the slag are reduced to metallic aluminium at the slag/electrode interface, while O2 - anions are oxidised to dissolved O in the metal pool. This Al and O subsequently recombine to form alumina inclusions in the metal pool. The inclusion content was dependent on the alumina content in the slag. When a rod of plain carbon steel was remelted, however, the increase in nonmetallic inclusion content was as little as one-tenth of that for the remelted Fe-Ni rod. The non-metallic inclusion content was independent of the polarity of the electrode.

A major water quality problem in smolt farms: combined effects of carbon dioxide, reduced pH and aluminium on Atlantic salmon ( Salmo salar L.) smolts: physiology and growth

Hatchery reared Atlantic salmon ( Salmo salar L.) smolts (mean start weight 80 g) in soft freshwater were exposed to three levels of carbon dioxide partial pressure for 38 days (25 days for the high group) in an open flow system: 0.5 mm Hg (1.8 mg/l CO 2; pH 6.6; control group), 2.7 mm Hg (9.3 mg/l CO 2; pH 6.0; medium group) and 5.7 mm Hg (19.4 mg/l CO 2; pH 5.7; high group). The different pH levels were a consequence of the addition of carbon dioxide to the water. Water temperature was 6–8 °C and effluent oxygen levels above 9 mg/l. During the experiment, the total aluminium concentration in the water was relatively stable in the range 115–140 μg/l. Labile Al concentration was low in all groups (about 10 μg/l). Despite this, the mean gill aluminium deposition was five times and seven times higher in the medium and high carbon dioxide groups, respectively, compared with the control group ( p<0.05). Mean respiration frequency was significantly increased both in the medium and high carbon dioxide groups compared to the control group ( p<0.05). The main gill lesions observed in the groups with elevated CO 2 were focal to diffuse hypertrophy and hyperplasia of chloride cells and adhesion of lamellae. Even though no significant differences were found in mean plasma cortisol concentrations in the medium group compared to the control group at any sampling time, mean plasma chloride and gill Na +,K +-ATPase activity in the medium group were lower than controls on day 19 ( p<0.05) and the mean condition factor was significantly reduced on day 38 ( p<0.05). The overall specific growth rate (SGR) for the medium group was −0.06%/day compared to 0.26%/day for the control group between days 3 and 38. After 38 days, accumulated mortality for the control group and the medium group was 0.4% and 4%, respectively. Days 2 and 19 mean plasma cortisol and hematocrit were significantly increased in the high group, and mean plasma chloride concentration was significantly reduced compared to the control group. There was a significant depression in gill Na +,K +-ATPase activity between days 2 and 19 ( p<0.01) in the high CO 2 group, to a level of approximately 30% of control levels. The specific growth rate for this group was negative (−0.25%/day) between days 3 and 38. Accumulated mortality in the high group was 42% after 25 days and the experiment was discontinued for ethical reasons. The present investigation has shown that the build-up of carbon dioxide, reduction in pH and the changes in Al chemistry may be detrimental to Atlantic salmon smolts even at low concentrations. Further investigations are, however, needed to study combined effects of aluminium, pH and carbon dioxide and effects of each parameter in isolation on Atlantic salmon smolts.

Modification of an ecotoxicological rating to bioassess small acid mine drainage‐impacted watersheds exclusive of benthic macroinvertebrate analysis

The modified ecotoxicological rating (METR) approach to synthesizing integrative bioassessment data into a single number ranging from 0 to 100 was found to differentiate between multiple levels of impacts from acid mine drainage (AMD). Our objective was to develop a more cost-effective and time-efficient bioassessment technique than previously used in other large scale ecotoxicological ratings (ETRs) by minimizing the number of parameters required to rank stations to only those most descriptive of the benthic macroinvertebrate community responses to AMD. Nineteen physical, chemical, toxicological, and ecological measurements were made at 38 stations in two adjacent watersheds. The most descriptive parameters were selected through multiple linear regression analysis, bivariate correlation analysis, and one-way analysis of variance. We found that habitat assessment, 30-d in situ Asian clam survival, mean conductivity, and mean total water column concentration of aluminum and manganese were the most descriptive parameters. The METR constructed from these parameters was equally effective at differentiating stations as were two previous published ETRs that incorporated up to 10 parameters, including benthic macroinvertebrate indices. When the METR was applied to a new watershed, the scores were significantly correlated with benthic macroinvertebrate indices for those stations.

The clinical impact of aluminium overload in renal failure.

Chronic aluminium exposure and toxicity related to aluminium absorption and contaminated dialysis fluid continue to be a problem for many patients with renal failure, particularly in South America and in some developing countries. The two most prevalent sources of aluminium in this population are water used to prepare dialysate and aluminium-containing phosphate binders. Of particular concern is the effect of aluminium at the level of the bone, the haematopoietic system and the brain. Here we focus mainly on the adverse effects of aluminium on bone, the preferred organ of aluminium accumulation in the body. Unfortunately, aluminium has a cumulative effect, thus even short-term exposure to aluminium in phosphate binders adds to the total load and may contribute to the risk of aluminium-related bone disease. Even a bone biopsy does not allow a precise determination of total bone aluminium content. We examine the mechanisms by which aluminium contributes to abnormal bone remodelling. Studies indicate that aluminium has a direct effect, inhibiting bone formation and resorption. There is also evidence for an indirect effect through the action of aluminium on parathyroid hormone synthesis and by its modulation of calcium activity. We discuss commonly used techniques for identifying aluminium load and review studies of chelation therapy as a method to lower aluminium load. It is apparent that aluminium overload has serious consequences for patients with chronic renal failure, yet this problem can be largely prevented by the use of aluminium-free phosphate binders. The deleterious effects on bone remodelling caused by chronic exposure to aluminium suggest that caution should be observed when using other metals as phosphate binders.

Identification of Anomalous Aluminium Contents in Surface and Ground Water in the Alba Territory (NW Italy)

Aluminium was determined in surface and ground waters in the Alba region of NW Italy to provide information on natural and anthropogenic sources of contamination. Determinations were made by a spectrophotometric method based on the aluminium‐pyrocatechol complex. The total aluminium content of waters was determined as well as the toxic form of monomeric aluminium, obtained from samples that had been passed through 0.20 μm cellulose filters to remove colloidal and particulate material. Results were correlated with mortality data associated with Alzheimer's disease. There appeared to be a correlation between mortality data and areas having the highest aluminium content of water.

Factors Controlling Total Concentration and Aqueous Speciation of Aluminium in an Acidic Headwater Stream of the Bavarian Forest National Park: a Modelling Approach

The purpose of the present paper is to analyse factors controlling total concentration and aqueous speciation of aluminium in the Grose Ohe River, using a thermodynamic equilibrium model and a mixing approach. A model compound for humic substances is derived on the basis of the relation between anion deficit and the organic carbon content in the river as well as literature data. An equilibrium speciation model for aluminium is set up, considering this model compound and relevant inorganic solutes. Although the model cannot be verified directly, its results may be viewed as qualitatively correct. Applying the model to measured stream water samples highlights that aqueous speciation of aluminium is mainly controlled by the pH value and discharge and that free aluminium concentrations reach clearly toxic levels during acidic episodes. Comparing measured concentrations of sulfate and H+ and calculated concentrations of Al3+ with solubility curves of gibbsite like minerals and jurbanite clearly shows that total aluminium concentrations are not controlled by equilibria with these mineral phases alone. The observed relationship can be better explained from a mixture of two distinct waters, representing lowflow and highflow chemistry, and the resulting equilibrium concentrations. This indicates that total aluminium concentration, in particular during high discharge events, is mainly controlled by the mixture of waters with differing chemistry and flowpaths. Kontrollfaktoren fur die Gesamtkonzentration und die wassrige Speziierung von Aluminium in einem sauren Quellfluss im Nationalpark Bayerischer Wald: Ein Modellansatz Ein Gleichgewichtsmodell und ein Mischungsansatz werden verwendet, um die Kontrollmechanismen fur die Speziierung und die Gesamtkonzentration von gelostem Aluminium in der Grosen Ohe zu analysieren. Auf Grundlage von Literaturdaten und der Beziehung zwischen Anionendefizit und organisch gebundenem Kohlenstoff wird eine Modellsubstanz fur die im Wasser enthaltenen Huminstoffe abgeleitet und zusammen mit relevanten anorganischen Spezies ein Modell fur die Aluminiumspeziierung aufgestellt. Wenngleich dieses nicht direkt verifiziert werden kann, sind auf seiner Grundlage qualitative Aussagen moglich. Die Anwendung des Modells auf im Bachwasser gemessene Konzentrationen verdeutlicht, dass die Speziierung von Aluminium durch das Abflussgeschehen gesteuert wird und wahrend Versauerungsschuben offenkundig toxische Konzentrationen freien Aluminiums auftreten. Aus dem Vergleich der gemessenen Sulfat- und H+- und der berechneten Al3+-Konzentrationen mit den Loslichkeitskurven von Gibbsit und Jurbanit wird deutlich, dass die Aluminiumkonzentration nicht ausschlieslich durch Gleichgewichte mit diesen Mineralphasen gesteuert wird. Die beobachteten Konzentrationsbeziehungen lassen sich besser aus der Mischung zweier Wasser (Basis- bzw. Hochwasserabfluss) und den sich hieraus ergebenden Gleichgewichtskonzentrationen erklaren. Insbesondere bei Hochwasser wird die Aluminiumkonzentration offenbar durch die Mischung von Wassern mit unterschiedlichen Abflussbildungsprozessen und Chemismen gesteuert.

Metal-triggered structural transformations, aggregation, and fibrillation of human alpha-synuclein. A possible molecular NK between Parkinson's disease and heavy metal exposure.

Parkinson's disease involves the aggregation of alpha-synuclein to form fibrils, which are the major constituent of intracellular protein inclusions (Lewy bodies and Lewy neurites) in dopaminergic neurons of the substantia nigra. Occupational exposure to specific metals, especially manganese, copper, lead, iron, mercury, zinc, aluminum, appears to be a risk factor for Parkinson's disease based on epidemiological studies. Elevated levels of several of these metals have also been reported in the substantia nigra of Parkinson's disease subjects. We examined the effect of various metals on the kinetics of fibrillation of recombinant alpha-synuclein and in inducing conformational changes, as monitored by biophysical techniques. Several di- and trivalent metal ions caused significant accelerations in the rate of alpha-synuclein fibril formation. Aluminum was the most effective, along with copper(II), iron(III), cobalt(III), and manganese(II). The effectiveness correlated with increasing ion charge density. A correlation was noted between efficiency in stimulating fibrillation and inducing a conformational change, ascribed to formation of a partially folded intermediate. The potential for ligand bridging by polyvalent metal ions is proposed to be an important factor in the metal-induced conformational changes of alpha-synuclein. The results indicate that low concentrations of some metals can directly induce alpha-synuclein fibril formation.

A preliminary study of the dermal absorption of aluminium from antiperspirants using aluminium-26

Aluminium chlorohydrate (ACH), the active ingredient in many antiperspirants, was labeled with the radioisotope 26Al. The labeled ACH was then fractionated into about 100 samples using gel filtration chromatography. Each fraction was analyzed for 26Al and total aluminium content. Aluminium-26 was only detected in the fractions that also contained aluminium, which verified that the ACH was uniformly labeled. 84 mg of the labeled ACH was then applied to a single underarm of two adult subjects with blood and urine samples being collected over 7 weeks. Tape-stripping and mild washings of the skin were also collected for the first 6 days. Results indicate that only 0.012% of the applied aluminium was absorbed through the skin. At this rate, about 4 μg of aluminium is absorbed from a single use of ACH on both underarms. This is about 2.5% of the aluminium typically absorbed by the gut from food over the same time period. Therefore, a one-time use of ACH applied to the skin is not a significant contribution to the body burden of aluminium.

Total aluminium and lead content in eastern Mediterranean rainwaters

Total aluminium and lead content in eastern Mediterranean rainwaters

Spatial variations in total aluminum concentrations in drinking water supplies studied by geographic information system (GIS) methods

Aluminum sulfate (alum) is routinely added in many water treatment systems as a coagulant. Some amount of aluminum may persist in the filtered water designated for human consumption. However, there are no reliable data to predict the magnitude of residual concentrations that would reach consumers’ taps. Studies in the United States, Canada, Europe, and Japan associated aluminum in tap water with various health problems, most notably, neuro-skeletal disorders and cognitive impairments. Whether or not aluminum in the drinking water is, indeed, a risk factor for these diseases has not been resolved conclusively. However, evidence has accumulated to suggest that it might be prudent to minimize residual aluminum in drinking water supplies. Harris County, Texas, by virtue of its multiple water supply sources and treatment methods, provides a unique opportunity to study spatial variations in concentrations of aluminum in the tap water within a defined geographic location. Statistical analysis of sampling results, coupled with GIS mapping, showed a range of variations, from none detected to as much as 530 μg/l of total aluminum in tap water. Peak concentrations were associated with source water treated with alum and were 2.5 times in excess of 200 μg/l currently recommended for public drinking water supplies. Median concentrations in the alum-treated water were up to five times greater than in raw water, regardless of its origin (surface or ground), and greater than in the water treated with an alternative coagulant (ferric chloride). Our findings show that options exist to minimize residual aluminum and these options need to be explored.

Analysis of aluminum-26 labeled aluminum chlorohydrate

A small quantity of aluminum chlorohydrate (ACH), the active ingredient in antiperspirants, was labeled with the radioisotope 26Al. This labeled drug will be used in future studies to measure the absorption of aluminum from antiperspirant use. The purpose of this study was to demonstrate that the technique used to make the 26Al-labeled ACH resulted in a uniformly labeled complex, and therefore any measurement of 26Al would be indicative of total aluminum. The labeled ACH was fractionated using gel filtration chromatography into 72 evenly spaced samples. The fractions were then measured for 26Al and total aluminum content using accelerator mass spectrometry (AMS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results indicate that the ACH is uniformly labeled.