Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Mechanisms Accompanying Chromium Release from Concrete.

ABSTRACT: The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related to the leaching of chromium from concretes made of Portland cement CEM I and slag cement CEM III/B (containing 75% of granulated blast furnace slag). Concrete was evaluated for leaching mechanisms that may appear during tank test over the long term (64 days). It has been presented that the dominating process associated with the leaching of chromium from both types of concrete is surface wash-off. Between the 9th and 64th day of the test, leaching of Portland cement concrete can be diffusion controlled. It has been proven that the participation of slag in the composition of concrete does not affect the level of leaching of chromium into the environment from concrete.

SUBMITTER: Krol A

PROVIDER: S-EPMC7216133 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Mechanisms Accompanying Chromium Release from Concrete.

Król Anna A

Materials (Basel, Switzerland) 20200417 8

The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related to the leaching of chromium from concretes made of Portland cement CEM I and slag cement CEM III/B (containing 75% of granulated blast furnace slag). Concrete was evaluated for leaching mechanisms that ma ...[more]

PMID: 32316506

Similar Datasets

Chromium released from leather - I: exposure conditions that govern the release of chromium(III) and chromium(VI).

Project description:BackgroundApproximately 1-3% of the adult population in Europe is allergic to chromium (Cr). A new restriction in REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) based on the ISO 17075 standard has recently been adopted in the EU to limit Cr(VI) in consumer and occupational leather products.ObjectivesThe aim of this study was to critically assess key experimental parameters in this standard on the release of Cr(III) and Cr(VI) and their relevance for skin exposure.Material and methodsFour differently tanned, unfinished, leather samples were systematically investigated for their release of Cr(III) and Cr(VI) in relation to surface area, key exposure parameters, temperature, ultraviolet irradiation, and time.ResultsAlthough the total release of Cr was largely unaffected by all investigated parameters, except exposure duration and temperature, the Cr oxidation state was highly dynamic, with reduced amounts of released Cr(VI) with time, owing to the simultaneous release of reducing agents from the leather. Significantly more Cr(III) than Cr(VI) was released from the Cr-tanned leather for all conditions tested, and it continued to be released in artificial sweat up to at least 1 week of exposure.ConclusionsSeveral parameters were identified that influenced the outcome of the ISO 17075 test.

| S-EPMC4415597 | biostudies-literature

Chromium(III) and chromium(VI) release from leather during 8 months of simulated use.

Project description:BackgroundChromium (Cr) release from Cr-tanned leather articles is a major cause of Cr contact dermatitis. It has been suggested that Cr(VI) release from leather is not necessarily an intrinsic property of the leather, but is strongly dependent on environmental conditions.ObjectivesTo test this hypothesis for long-term (8?months) simulated use.Materials and methodsThe release of total Cr and Cr(VI) from Cr-tanned, unfinished leather was analysed in subsequent phosphate buffer (pH?8.0) immersions for a period of 7.5?months. The effect of combined ultraviolet treatment and alkaline solution (pH?12.1) was tested. Dry storage [20% relative humidity (RH)] was maintained between immersions. Atomic absorption spectroscopy, X-ray fluorescence and diphenylcarbazide tests were used.ResultsCr(VI) release was dependent on previous dry storage or alkaline treatment, but not on duration or number of previous immersions. Cr(III) release decreased with time. Fifty-two percent of the total Cr released during the last immersion period was Cr(VI). Cr(VI) release exceeded 9?mg/kg in all immersion periods except in the first 10-day immersion (2.6?mg/kg).ConclusionsCr(VI) release is primarily determined by environmental factors (RH prior to immersion, solution pH, and antioxidant content). The RH should be kept low prior to testing Cr(VI) release from leather.

| S-EPMC5084788 | biostudies-literature

Chromium(III) release from chromium-tanned leather elicits allergic contact dermatitis: a use test study.

Project description:BACKGROUND:Chromium (Cr) is a common skin sensitizer. The use of Cr(VI) in leather is restricted in the EU, but that of Cr(III) is not. OBJECTIVES:To assess whether prolonged exposure to Cr-tanned leather with mainly Cr(III) release may elicit allergic contact dermatitis in Cr-allergic individuals. METHOD:Ten Cr-allergic subjects and 22 controls were patch tested with serial dilutions of Cr(III) and Cr(VI), and with leather samples. They then conducted a use test with a Cr-tanned and a Cr-free leather bracelet over a period of 3?weeks, for 12?h per day. Cr deposited on the skin from the bracelets was measured in the controls, and the diphenylcarbazide test for Cr(VI) and extraction tests for Cr(III) and Cr(VI) were conducted for the different leathers. RESULTS:Four of 10 Cr-allergic subjects developed positive reactions to the Cr-tanned bracelet within 7-21?days, whereas only 1 of 10 had a positive patch test reaction to this leather. Cr released from the Cr-tanned leather was most probably entirely Cr(III), with a quantifiable amount being deposited on the skin. CONCLUSIONS:This study strongly suggests that prolonged and repeated exposure to Cr-tanned leather with mainly Cr(III) release is capable of eliciting allergic contact dermatitis in Cr-allergic individuals.

| S-EPMC5901407 | biostudies-literature

concrete metagenome

Project description:Concrete from concrete wall Metagenome

| PRJNA302836 | ENA

concrete metagenome

Project description:Degraded concrete road bridge metagenome

| PRJNA846790 | ENA

Chromium oxide coatings with the potential for eliminating the risk of chromium ion release in orthopaedic implants.

Project description:Chromium oxide coatings prepared by radiofrequency reactive magnetron sputtering on stainless steel substrates were exposed to Ringer's physiological solution and tested for their electrochemical corrosion stability using an open circuit potential measurement, potentiodynamic polarization, electrochemical impedance spectroscopy and Mott-Schottky analysis. The coatings were found to be predominantly Cr2O3, based on the observation of the dominance of [Formula: see text] and Eg symmetric modes in our Raman spectroscopic investigation and the Eu vibrational modes in our Fourier transform infrared spectroscopic measurements on the coatings. We investigated for the presence of chromium ions in Ringer's solution after all of the above electrochemical tests using atomic absorption spectroscopy, without finding a trace of chromium ions at the ppm level for coatings tested under open circuit and at the lower potentials implants are likely to experience in the human body. The coatings were further exposed to Ringer's solution for one month and tested for adhesion strength changes, and we found that they retained substantial adhesion to the substrates. We expect this finding to be significant for future orthopaedic implants where chromium ion release is still a major challenge.

| S-EPMC5541545 | biostudies-other

Synapse-specific and size-dependent mechanisms of spine structural plasticity accompanying synaptic weakening.

Project description:Refinement of neural circuits in the mammalian cerebral cortex shapes brain function during development and in the adult. However, the signaling mechanisms underlying the synapse-specific shrinkage and loss of spiny synapses when neural circuits are remodeled remain poorly defined. Here, we show that low-frequency glutamatergic activity at individual dendritic spines leads to synapse-specific synaptic weakening and spine shrinkage on CA1 neurons in the hippocampus. We found that shrinkage of individual spines in response to low-frequency glutamate uncaging is saturable, reversible, and requires NMDA receptor activation. Notably, shrinkage of large spines additionally requires signaling through metabotropic glutamate receptors (mGluRs) and inositol 1,4,5-trisphosphate receptors (IP(3)Rs), supported by higher levels of mGluR signaling activity in large spines. Our results support a model in which signaling through both NMDA receptors and mGluRs is required to drive activity-dependent synaptic weakening and spine shrinkage at large, mature dendritic spines when neural circuits undergo experience-dependent modification.

| S-EPMC3557099 | biostudies-literature

Hexavalent chromium release over time from a pyrolyzed Cr-bearing tannery sludge.

Project description:Pyrolysis in an inert atmosphere is a widely applied route to convert tannery wastes into reusable materials. In the present study, the Cr(III) conversion into the toxic hexavalent form in the pyrolyzed tannery waste referred to as KEU was investigated. Ageing experiments and leaching tests demonstrated that the Cr(III)-Cr(VI) inter-conversion occurs in the presence of air at ambient temperature, enhanced by wet environmental conditions. Microstructural analysis revealed that the Cr-primary mineral assemblage formed during pyrolysis (Cr-bearing srebrodolskite and Cr-magnetite spinel) destabilized upon spray water cooling in the last stage of the process. In the evolution from the higher to the lower temperature mineralogy, Cr is incorporated into newly formed CrOOH flakes which likely react in air forming extractable Cr(VI) species. This property transforms KEU from an inert waste to a hazardous material when exposed to ordinary ambient conditions.

| S-EPMC10539330 | biostudies-literature

A Review on Bubble Stability in Fresh Concrete: Mechanisms and Main Factors.

Project description:In order to improve the stability of air bubbles in fresh concrete, it is of great significance to have a better understanding of the mechanisms and main influencing factors of bubble stability. In the present review, the formation and collapse process of air bubbles in fresh concrete are essentially detailed; and the advances of major influencing factors of bubble stability are summarized. The results show that the surface tension of air-liquid interface exerts a huge impact on bubble stability by reducing surface free energy and Plateau drainage, as well as increasing the Gibbs surface elasticity. However, surface tension may not be the only determinant of bubble stability. Both the strength of bubble film and the diffusion rate of air through the membrane may also dominate bubble stability. The application of nano-silica is a current trend and plays a key role in ameliorating bubble stability. The foam stability could be increased by 6 times when the mass fraction of nano-particle reached 1.5%.

| S-EPMC7215813 | biostudies-literature

concrete sediment 16s

Project description:concrete sediment 16s Raw sequence reads

| PRJNA1107968 | ENA