Concentration Levels Of Cr Research Articles

Physical-Chemical Properties and Spatial Distribution of Heavy Metals in Agriculture Soil in Al-Qadisiyah City by using ArcGIS and Multivariate Analysis

Al-Qadisiyah governorate is one of the most important agricultural areas in Iraq, and the study was conducted in different areas of the governorate, including seven areas for sampling. The physical-chemical properties and heavy metals of agricultural soils were examined. The results showed that highest value was Ni (189.9 mg/kg) followed by Cr (124.5 mg/kg), Zn (50.8 mg/kg), Cu (36.9 mg/kg), Pb (35.2 mg/kg) and Cd (1.17 mg/kg). Moreover, Ni and Cr concentration levels were higher than Canadian soil guidelines. Geostatistical analysis was applied to know the sources of heavy metals in agricultural soil and results were revealed that Zn, Cu, Ni, and Cr were the same pollution sources and Cd and Pb also were the same pollution sources indicating these elements impacted by anthropogenic activities. The Pearson correlation coefficients found some physical-chemical properties role in increasing heavy metals in the soil such as EC and Cu, and also TOC, OM and Cr. Therefore, these results are considered useful for the competent authorities in order to reduce and control these pollutants in agricultural soils.

Diffuse transmitted spectroscopy in conjunction with spectral peak averaging as a potential tool for noninvasive creatinine screening

Creatinine (Cr) is a biochemical waste molecule generated from muscle metabolism and primarily cleared from the bloodstream by the kidneys. If kidney function declines, Cr levels in the blood tend to increase. Therefore, Cr serves as an indicator of kidney function. In this work, we present a simple method for the rapid screening for impaired renal function based on the subject’s Cr concentration. In our setup, broadband white light is delivered to a finger clamp through a fiber-optic cable to illuminate the patient’s finger. The light is transmitted through the finger and collected by a second optical fiber coupled to a visible–near-infrared (VisNIR) spectrometer which covers the spectral range from 400[Formula: see text]nm to 1100[Formula: see text]nm. During the calibration process, the transmitted spectra acquired from 60 patients were measured. An average was calculated using the peak level of the transmitted, diffused intensity at three different wavelengths to create a “Cr intensity index”. Patients were divided into five groups according to their Cr concentration levels, ranging from 1[Formula: see text]mg/dL to 13[Formula: see text]mg/dL. Our observations indicated that each group featured a unique spectral fingerprint. Next, we tested the index on 20 patients not included in the calibration procedure (unknown samples). We were able to classify patients into groups according to their Cr level with moderate prediction accuracy ([Formula: see text]) and mean screening error of up to 16%. Future efforts will evaluate the accuracy of this approach with larger patient populations representing a broad range of Cr concentration. Still, this preliminary work is an essential step toward developing this useful noninvasive Cr screening platform using NIR light spectroscopy.

New composite sorbent for speciation analysis of soluble chromium in textiles

AbstractMicrometer-sized silica spheres coated with a layer of Cr(VI) imprinted methylimidazolium ionic liquid were synthesized and applied for fast and selective determination of leachable Cr(VI) in fabrics. The silica cores were synthesized via original seeded growth procedure. Formation of ionic liquid layer onto their surface was simultaneously combined with CrO42− imprinting. The sorbent characterization was accomplished by SEM/ EDS, elemental microanalysis, and thermogravimetry. Excellent separation of Cr(VI) from Cr(III) was achieved at pH 3 for 10 minutes in a batch mode. A mixture of ascorbic and nitric acids was found to be the most efficient eluent. The adsorption equilibrium data were best represented by the Langmuir isotherm model. The sorbent was applied for quantification of Cr(VI) in textile extracts in accordance with international standard ISO105-E04. The analytical procedure developed (LOD 0.015 μg/g (measured by ETAAS), RSD 3−8% for concentration levels of Cr(VI) 0.015-0.5 μg/g) completely meets the requirements of the international textile regulations.

Thyroid dysfunction: how concentration of toxic and essential elements contribute to risk of hypothyroidism, hyperthyroidism, and thyroid cancer.

This study was conducted to evaluate the levels of trace metals Fe, Cr, Co, Cd, Cu, Ni, Hg, Zn, and Pb in healthy individuals and patients with thyroid disease (hyperthyroidism, hypothyroidism, and cancerous). The serum levels of 110 participants living in Birjand City, east of Iran, were collected and analyzed using ICP-MS (Agilent 7900). Results showed that the concentration levels of Cr, Co, Zn, Cd, and Pb were significantly higher at case-patients (p < 0.05), but the levels of Fe, Ni, and Hg were similar between healthy and patient subjects (p > 0.05). In patients with high or low thyroid activity, strong mutual correlations between Cr, Ni, and Fe were noticeable (p < 0.05). In hypothyroid patients, no significant correlation between Zn and Hg, Co, and Cd was found, but Zn was moderately and positively correlated with other trace metals. The moderate negative correlations between Cd-Cr (p = - 0.46) and Cd-Fe (p = - 0.43) were also observed. Logistic regression analysis showed that the effect of Cr, Co, Pb, Cu, Zn, and Cd was significant in developing hyperthyroidism and hypothyroidism; whereas, in patients with thyroid cancer, the effect of Cr, Cd, and Pb was found to be significant. In conclusion, our findings suggest that toxic metals such as Pb, Cd, and Cr can increase the risk of developing hypothyroidism and thyroid cancer, but more research is needed to evaluate the potential toxicity mechanisms of Pb, Cd, and Cr.

Assessment of groundwater geochemistry and diffusion of hexavalent chromium contamination in an industrial town of Italy

Groundwater contamination by hexavalent chromium (Cr (VI)) is currently a very serious and challenging issue. Therefore, in the present study, 108 shallow groundwater samples were collected during the years 2012 to 2015 (n = 27 samples each year) from an industrial town (Aosta) to assess the contamination status of the area. To evaluate the Cr (VI) concentration level, sources of pollutants and groundwater geochemistry of the study area, a combined approach of the multi-statistical and hydrogeochemical techniques were used. Furthermore, a geographic information system (GIS) was applied for the spatial distribution of Cr (VI) so that the most contaminated sites can be identified for a quick decision by policymakers. Results show that the groundwater chemistry was dominated by HCO3– and SO42− in the anionic chemistry and Ca2+ and Na+ in the cationic chemistry, while Ca-Mg-HCO3 and Ca-Mg-Cl-SO4 were the main water types during the years 2012–2015 in the study area. The central part and some north-eastern parts of the Aosta town groundwater was contaminated with Cr (VI) and are unsafe for drinking use. Concentration levels of Cr (VI) in the groundwater were 0.09 μg/L (lowest value) and 165 μg/L (highest value) in the years studied, and the spatial analysis shows the diffusion of Cr (VI) to north-east direction from the source. Contamination of Cr (VI) in the groundwater was due to the superficial slag deposits from a steel company within the study area. This study would be helpful for current and future water resource management in the area concerned.

Transport and fate of hexavalent chromium in slag–soil system

The transport and fate of hexavalent chromium Cr(VI) in slag–soil system, which remain poorly understood, are of great importance for environmental risk assessment and pollution control of Cr(VI) in soil and groundwater. Based on the migration behavior of Cr(VI) in the chromium-containing slag under the effects of rainfall, the transport and fate of Cr(VI) in soil were investigated. Batch and column experiments were undertaken to clarify the Cr(VI) adsorption and transport behavior of aqueous Cr(VI) in soil, respectively. Findings from a combination of experimental and model results clearly suggest that the adsorption of Cr(VI) onto soil is a spontaneous chemical adsorption process. For chromium-soil transport system, the constructed HYDRUS-1D dynamics model is a good simulation for Cr(VI) migration in soil, as the modeling yielded adequate fit for simulated and measured values of Cr(VI) concentration in soil (correlation coefficient R2 = 0.99). The transport modeling then was utilized to assess the transport of Cr(VI) in slag–soil system. Up to the year of 2018, the concentration levels of Cr(VI) in the soil-leaching solution attained 905 mg/L. Due to the thin layer of soil and the high mobility of Cr(VI) in soil, it is no doubt that the Cr(VI) leaching will engender serious pollution of soil and groundwater in the presence of precipitation. The applications and limitations of the HYDRUS-1D were also discussed, such as bacteria transport, more elaborate biogeochemical processes, coupling of vadose zone processes with existing larger scale groundwater flow models.

Concentration of Heavy Metals in Soil around Dumpsites in Jimeta and Ngurore, Adamawa State, Nigeria

Rapid urbanization and industrialization in developing countries have been associated with production and deposition of hazardous wastes in the soil environments. Heavy metals are major components of these wastes and have been implicated in several metal-related diseases and food poisoning in man. This study examined the concentration of Iron (Fe), Lead (Pb), Copper (Cu), Chromium (Cr), and Cadmium (Cd) heavy metals in soil near dumpsites of Jimeta and Ngurore, Yola North Local Government Areas (LGAs), Adamawa State. Soil samples from 0-20cm layer depth were collected in triplicates and analyzed using atomic absorption spectrophotometer (AAS). Results reveal that Fe, Pb, Cu and Chromium were detected, while Cadmium was found to be below the limit of detection. The mean concentration of the exchangeable cation in mg/kg in soil at Jimeta sites were: Fe (31.4 mg/kg) &gt;Pb (0.92 mg/kg) &gt; Cu (0.34 mg/kg) &gt; Cr (0.11 mg/kg) &gt;Cd (below limit of detection), while the mean concentration of the heavy metals in soil at Ngurore sites were: Fe (32 mg/kg) &gt;Pb (0.83 mg/kg) &gt; Cu (0.28 mg/kg) &gt; Cr (0.07 mg/kg) &gt;Cd (below limit of detection), respectively. Iron (Fe) was the most abundant element in both sites, followed by Pb. Heavy metal concentrations in soil followed the order of Fe&gt;Pb&gt;Cu&gt;Cr&gt;Cd, respectively. The paired T-test analyses for concentration of Cr, Fe, and Pb in soil nearthe two dumpsites show that there were statistically significant differences in the concentration levels of Cr, Fe, and Pb, while Cu showed no statistically significant difference between the two dumpsites. However, all the metals detected were below the permissible limit of WHO international standard with the exception of Pb whose concentration was above maximum permissible concentration (MPC). Persistent heavy metals accumulation in soils near these dumpsites may lead to increase uptake by vegetables grown near the dumpsites and this may pose a threat to its quality and safety and ultimately human health. The need to replace open dumpsites with well-designed landfills is advised.

Environmental quantification of soil elements in the catchment of hydroelectric reservoirs in India

ABSTRACTThe contamination of inorganic elements in soil is a serious environmental problem,. The aim of the present study is to investigate concentrations of 19 elements in order to access the extent of their contaminations in the surface soil of hydroelectric catchments, Uttarakhand, India. For analysis, 168 soil samples were divided into eight groups according to altitudes. In soil samples, the concentration levels of Cr and Cu were found more than their background and threshold limit. Moreover, the evaluation of geochemical index (Igeo), enrichment factor (EF), and contamination factor (CF) suggests that soil samples were reasonably contaminated and highly enriched in Rb. The pollution load index (PLI) and degree of contamination (Cd) revealed that the presence of contaminations (PLI: 1.44; Cd: 44.94) in the study site might be a possible health risk for local residents. However, the calculation pollution ecological risk index (PERI) suggests low ecological risk (PERI: 77.61) of these elements. The clustering of sampling groups contained two clusters: the first cluster comprised F1 and F4 while the second cluster consists of the rest of the sampling group. Multivariate statistical analysis revealed that the variation in concentrations of the elements might be a result of agricultural activities and pedological processes.

Chromate surface-imprinted silica gel sorbent for speciation of Cr in surface waters

This study is focused on the synthesis of chromate anion imprinted sorbent supported on silica gel for nonchromatographic Cr speciation in surface waters. The preparation procedure is based on grafting of 3-methyl-1-trimethoxysilylpropylimidazolium, preliminarily coordinated to CrO$_{4}^{2-}$ as a template ion, onto the surface of silica gel. Sorption and desorption characteristics of surface-imprinted sorbent toward Cr(III) and Cr(VI) were examined by batch solid-phase extraction. An excellent separation of Cr(VI), selectively retained on the sorbent, from Cr(III) remained in the solution, was achieved at pH 2-3 for 20 min. A freshly prepared mixture of ascorbic acid and nitric acid was selected as the most efficient eluent for quantitative desorption of the retained Cr(VI). An analytical procedure for Cr speciation in surface waters was developed and validated through analysis of certified reference materials. Detection limits achieved and relative standard deviations for typical concentration levels of Cr(VI) in surface waters matched the requirements of analytical procedures used in monitoring programs.

Predicting toxic heavy metal movements in upper Sanyati catchment in the midlands province in Zimbabwe

The study assessed toxic heavy metal concentrations in the upper Sanyati catchment in the Midlands Province in Zimbabwe and predicted their movements and potential impacts on ground water quality. Topographic surveying was used to determine borehole locations, elevations, hydraulic conductivity and water yields. Monthly ground water samples were analyzed to determine concentrations of Cr, Pb, Cd and Ni for a period of two-years. The results obtained for the wet season showed mean concentration levels of Cr, Pb, Cd and Ni at 0.25, 0.015, 0.042 and 0.031mg/L respectively. Dry season mean concentration levels for Cr, Pb, Cd and Ni were 0.15, 0.07, 0.06 and 0.025 mg/L respectively. Water samples from boreholes located in areas where mining, mineral processing and agricultural activities were dominant, yielded the highest values of toxic heavy metals. Dilution Attenuation Factor (DAF) for each toxic heavy metal was calculated to observe metal behaviour along the contaminant path for each season. The results showed seasonal variation in the spatial distribution of each toxic heavy metal during the wet season between October to March and during the dry season between April to September. Overall, research results showed that concentrations of Cr, Pb, Cd and Ni were above the standard limits set by the World Health Organization. Key Words : Heavy metals; Hydraulic conductivity; Ground water transportation; Contamination; Attenuation; Photometry.

Trace element fluxes and natural potential risks from 210Pb-dated sediment cores in lacustrine environments at the Central Mexican Plateau

The accumulation, enrichment and provenance of selected trace metals (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, V and Zn) were studied in sediment cores collected from three lakes located in the Central Mexican Plateau, selected on the basis of their contrasting degree of urbanization: Santa Elena Lake, in a rural and remote area; El Tule Lake, in a rural and slightly urbanized area; and Chapala Lake, in a highly urbanized area. Grain size, magnetic susceptibility and sedimentary constituents such as organic carbon, calcium carbonate, as well as major (Al, Fe, Mn) and minor (Ca, Li, Rb, Sr, Th) elements were analyzed to explain the concentration trends of trace metals. Factor analysis (FA) was used to assess the provenance of the trace elements. The highest metal enrichment factor (EF) above natural concentration levels was found at Chapala Lake for Ag (EF=3.9), although other trace element EF in all lakes was <2.0, indicating slight contamination. However, the concentration levels of Cr and Ni in all lakes, Hg and Zn in Chapala Lake, Cu in El Tule Lake and As in Santa Elena Lake were above international benchmarks for which adverse effects are expected to occur frequently, even for those metals only slightly enriched (e.g. As, Cr). Through FA, the terrigenous contribution was identified as the most important source of trace metals to the three lakes, most likely related to deforestation and erosion of the surrounding areas, followed by atmospheric transport of volcanic ashes, rather than to direct sources.

Effects of EDTA on Cr+3 Uptake, Accumulation, and Biomass in Nasturtium officinale (Watercress)

A pot study was used to examine the effects of ethylenediaminetetraacetic acid (EDTA) on the growth potential, uptake, and mobilization of Cr by Watercress (Nasturtium officinale) in contaminated water at different concentration levels of the chelating agent EDTA (0, 10-5, and 10-4 M) and four concentration levels of Cr (0, 1, 3, and 10 mgL-1). The EDTA resulted in more solubilization of Cr in water. The application of EDTA 15 d prior to harvest increased the amount of Cr accumulated in watercress with more Cr accumulated by the plants from the media. Nasturtium officinale accumulated high Cr concentration (317 mgkg -1 ) in the root at a concentration of 10 mgL -1 Cr 3+ and 10 4- M EDTA after 15 d growth. The application of EDTA had inhibitory effects on the root and shoot dry biomass compared with that in the

Effect of MgO and CaO/SiO2 on the immobilization of chromium in synthetic slags

This work investigated the chemical and mineralogical properties of CaO–SiO2–Cr2O3–CaF2–MgO slags. Synthetic slags were prepared and the effect of the slag basicity (mass ratio CaO/SiO2) and MgO contents on the stability of the mineralogical species formed was analyzed. The morphology and composition of the slags were analyzed by X-ray powder diffraction (XRD) and scanning electron microscope-energy dispersive spectroscopy (SEM–EDS), whilst their chemical stability was evaluated by leaching with an aqueous acetic acid solution. It was found that in slags with CaO/SiO2 = 1, the main Cr-compound was MgCr2O4 spinel, which forms octahedron crystals. Small amounts of CaCr2O4 and CaCrO4 were also observed. It was found that with increasing the slag basicity from 1 to 2 the compounds MgCr2O4 and CaCr2O4 were formed together with the Cr(V)-containing compound complex Ca5(CrO4)3F which forms hexagonal crystals. The results showed that the highest Cr concentration levels in the leaching liquors corresponded to slags with CaO/SiO2 = 2, probably owing to the formation of CaCrO4 and Ca5(CrO4)3F, whilst the lowest chromium concentration levels corresponded to MgO-based slags owing to the stable binding of chromium in spinel with MgO. Additionally, potential–pH diagrams for the Ca–Cr–H2O and Mg–Cr–H2O systems at 25 °C were calculated.

Correlation between degradation of cathode performance and chromium concentration in (La,Sr)MnO3 cathode

The relationship between the Chromium (Cr) concentration in the porous (La,Sr) MnO3 (LSM) cathode and the polarization resistance was examined at accelerated Cr poisoning conditions. By supplying Cr vapor (p(Cr)~10−8atm) to the porous LSM cathode the polarization resistances were increased significantly. Secondary ion mass spectrometry (SIMS) analysis of the LSM cathode suggested that an increase of Cr concentration levels both at the surface and at the triple phase boundary (TPBs) under polarization. The precise Cr concentration in the porous LSM cathode was successfully determined by SIMS to be in the orders of 0.0001–1wt.% levels. The deposited Cr at the TPB effectively reduced the cathode performance under polarization; and the deposited Cr concentration at the TPB was above 1wt.% in the Cr-poisoned cells. The polarization resistance increased with the Cr-concentration at the TPBs as well as at the cathode surface areas.

Proton Magnetic Resonance Spectroscopy in Adults with Childhood Lead Exposure

BackgroundChildhood lead exposure adversely affects neurodevelopment. However, few studies have examined changes in human brain metabolism that may underlie known adverse cognitive and behavioral outcomes.ObjectiveWe examined the association between mean childhood blood lead levels and in vivo brain metabolite concentrations as adults, determined by proton magnetic resonance spectroscopy (MRS) in a birth cohort with documented low-to-moderate lead exposure.MethodsAdult participants from the Cincinnati Lead Study [n = 159; mean age (± SD), 20.8 ± 0.9 years] completed a quantitative, short-echo proton MRS protocol evaluating seven regions to determine brain concentrations of N-acetyl aspartate (NAA), creatine and phosphocreatine (Cr), cholines (Cho), myo-inositol, and a composite of glutamate and glutamine (GLX). Correlation and multiple linear regression analyses were conducted.ResultsMean childhood blood lead levels were associated with regionally specific brain metabolite concentrations adjusted for age at imaging and Full-Scale intelligence quotient. Adjusted analyses estimated for a unit (micrograms per deciliter) increase in mean childhood blood lead concentrations, a decrease of NAA and Cr concentration levels in the basal ganglia, a decrease of NAA and a decrease of Cho concentration levels in the cerebellar hemisphere, a decrease of GLX concentration levels in vermis, a decrease of Cho and a decrease of GLX concentration levels in parietal white matter, and a decrease of Cho concentration levels in frontal white matter.ConclusionsGray-matter NAA reductions associated with increasing childhood blood lead levels suggest that sustained childhood lead exposure produces an irreversible pattern of neuronal dysfunction, whereas associated white-matter choline declines indicate a permanent alteration to myelin architecture.

Hybrid inorganic/organic alumina adsorbents-functionalized-purpurogallin for removal and preconcentration of Cr(III), Fe(III), Cu(II), Cd(II) and Pb(II) from underground water

Metal pollution is well recognized as one of the major environmental problems that must be imperatively addressed and solved. In this study, three types of alumina adsorbents (I–III) were physically immobilized with purporogallin as a chelating ion exchangers. These were found to exhibit strong capability and selectivity characters for a series of heavy metal ions. Surface modification of hybrid alumina was characterized and identified from the determination of surface coverage and infrared analysis. Hybrid alumina adsorbents were identified for their strong resistivity to acid leaching in pH > 2–7 as well as their high thermal stability up to 350 °C. The ability of newly synthesized hybrid inorganic/organic alumina adsorbents (I–III) to bind and extract various metal ions was examined and evaluated in various buffer solutions (pH 1.0–7.0) via determination of the metal adsorption capacity values. These were identified as high as 420–560, 500–580 and 500–590 μmol g −1 for alumina adsorbents (I), (II) and (III), respectively in the case of high concentration levels of Cr(III), Fe(III) and Cu(II). The influence of alumina matrices were highly characterized when low concentration levels (μg ml −1 and ng ml −1) of metal ions were used. Hybrid alumina adsorbents were successfully applied for selective extraction, removal and preconcentration of various heavy metals from underground water samples with percentage recovery values of 92–100 ± 1–3%.

Accumulation of chromium and histological findings on Hybro chickens kidneys treated with Cr(VI) and vitamin C

It was investigated the effect of both the C vitamin and Cr (VI) on bioaccumulation of Cr in the hystological findings on Hybro chickens kidneys. The chickens were divided into 5 groups (I‐V), each with 10 individulas. The first, was controll group, whereas other groups were treated for 180 days orally with different concentration levels of Cr (VI) and C vitamin (10 mg dose/kg b.w). Preparation of tissues for pathology microscopy was carried out according to standard procedures, whereas staining was done with hematoxylin‐eosin. The concentration of Cr in kidneys was measured with atomic absorbtion spectroscopy (AAS) and UNICAM 929‐AA. spectrometerThe results of our investigation have shown the occurence of little hystopathological changes on glomerule, intersticiel section and on blood vessels: Hydropic expansion and epithels desquamination of proximal tubules, vacoulization of cytoplasm, dylatation of distal tubules, expansion of subcapsular area of some glomerules, and a source of extravasate erythrocites in subcapsular area. Our findigs show that there were not any protective function of C vitamin with the dosage we have applied. C vitamin combined with Cr (VI) has significantly increased the bio‐accumulation of Cr in noted kidneys (ppm., FW) compared with control group chickens and those treated with only Cr (VI).

Determination of Chromium Concentration in Solid Oxide Fuel Cell Cathodes: (La,Sr)MnO[sub 3] and (La,Sr)FeO[sub 3

Chromium poisoning was investigated at the cathode/Gd 0.2 Ce 0.8 O 19 electrolyte interfaces under cathodic polarization by using a preoxidized Cr metal. The concentration levels of Cr in the porous cathodes [La 0.8 Sr 0.2 MnO 3 (LSM) and La 0.8 Sr 0.2 FeO 3 (LSF)] was first determined by secondary ion mass spectrometry. Maxima of Cr concentration were observed at the LSM/electrolyte interfaces (about 1000 ppm). On the other hand, no maxima of Cr concentration were observed with homogeneous distribution of Cr (1000-1700 ppm). The amount of Cr deposited in the LSF cathode is estimated to be about 21% of the supplied Cr and is about 1.6 times higher in the LSM.

Vaporization of components from alloy powder particles in a plasma flow

If molten alloy powder particles are plasma sprayed, their composition usually changes. This is due to the phenomena occurring mainly at the in-flight stage of spraying, in particular to selective oxidation and selective transport of elements to the gas phase (vaporization). The present paper deals with selective vaporization of Al and Cr from four binary alloy powders: Fe-Al, Fe-Cr, and Ni-Cr with two Cr concentration levels.

Determining controls on element concentrations in cement kiln dust leachate

Cement kiln dust is a waste residue composed chiefly of oxidized, anhydrous, micron-sized particles generated as a by-product of the manufacture of Portland cement. When cement kiln dust is brought into contact with water, high concentrations of potassium, sulfate and caustic alkalinity are leached. Other constituents are leached to a lesser extent. The objective of this study was to determine whether the concentration of a given chemical constituent in kiln dust leachate is controlled by the precipitation of a secondary mineral phase or whether its concentration depends on its initial availability to the leachate solution and its subsequent diffusive flux from hydrating particles with time. Differentiating between these two distinctive styles of leaching behavior is necessary to predict the chemical composition of kiln dust leachate under dynamic flow conditions in disposal environments. Evidence of solubility control was found for Si, Ca, Mg, Al, Zn, Ti, Sr, and Ba. The concentrations of Na, Cl, K, Mo, Cr and Se, however, were found to have no solubility control. Because of the observed lack of solubility control and the particularly high concentrations of Cr and Mo in kiln dust leachate, we tested two additives (at 10 mass%) to reduce their concentrations: (1) aluminum oxide to promote the precipitation of calcium aluminosulfates and the proxying of chromate and molybdate for sulfate in their structures; and (2) iron metal to promote the reduction of chromate and molybdate to lower valent and less soluble forms. Neither treatment had any effect on the concentration levels of Cr and Mo in solution. ©