A sensitive and selective method has been developed for the speciation of chromium in water samples based on cloud point extraction (CPE) separation and preconcentration and determination by flame atomic absorption spectrometry. In the CPE method, Cr(III) reacts with acetylacetone yielding a hydrophobic complex, which is …

The extraction efficiency for CCA elements increased with increasing the concentration of wood vinegar and the extraction conditions, resulting in maximal removal rate of copper (95.7%), followed by arsenic (92.7%) and chromium (86.3%). Since wood vinegar afforded high levels of copper extraction, its use was extended to copper-based ...

Chromium speciation is a two step process and involves complicated chemistry to perform the extraction without interconversion of the two predominant …

Chromium is a naturally-occurring element found in rocks, animals, plants, soil, and in volcanic dust and gases. Chromium is mined in two different ways: underground mining and surface mining. Underground mining is used to reach deeper deposits. It involves digging a tunnel into the Earth, then blasting and excavating the ore.

The extraction of chromium (VI) from aqueous solutions of 0.1 m ionic strength by trioctylmethylammonium compounds (Aliquat 336) in a mixture of kerosene and xylene was investigated. The results ...

However, this high-temperature separation method has yet to attract attention in vanadium-chromium slag vanadium extraction. Hence, a compelling need is to investigate a new, cost-effective, streamlined approach for separating and extracting V and Cr from high-temperature heating V-Cr slag. This innovative approach represents a novel method for ...

Basic oxygen furnace slags (BOS) are by-products of basic oxygen steel production. Whereas the solubility of some elements from these slags has been well investigated, information about the mineralogy and related leaching, i.e., availability of the environmentally relevant elements chromium (Cr), molybdenum (Mo), and vanadium …

Here we report a viable strategy to efficiently extract Cr from four different Cr-containing wastes (chromium ore processing residue, tannery sludge, electroplating sludge and stainless steel slag) by a …

1. Introduction. Chromium (Cr) resource is extensively used in electroplating, stainless steel manufacturing, and leather tanning (Barnhart, 1997, Fang et al., 2018).China is lack of Cr resource (Peng et al., 2021); thus, the Cr-containing tailings resulted from other resource extraction processes are essential in China (Gu et al., 2021, Ibraev et al., …

In the last five decades numerous physico-chemical and bio-chemical mechanisms have been proposed for the detection of chromium speciation, extraction …

A procedure using disposable pipette tips adapted for solid-phase extraction, known as DPX‑SPE, was used as an alternative way for the chromium determination in wastewater samples.

AbstractThe extraction equilibrium of Cr(VI) with trialkylamine (N235, R3 N, R = C8–C10) using kerosene as the diluent was investigated. The influence of various analytical parameters such as pH, equilibrium time, temperature, extractants, and diluents was systematically evaluated. The structure of organic solution was identified by Fourier …

Novel extraction of sustainable continuous emulsion liquid membrane (ELM) comprising ionic liquid extractants ([TOMA +][Cl −]) and palm oil as green diluent …

The chief ore of chromium is chromite ore. Extraction of chromium metal from chromite ore. The extraction of chromium metal from chromite ore consists of the following steps. 1. Concentration. The crushed ore is concentrated by gravity separation method. 2. Conversion of the concentrated chromite ore into Na2CrO4.

Liquid-liquid extraction of chromium (VI) from synthetic waste solution using Alamine 336/kerosene was investigated. The extraction conditions were evaluated by varying the experimental parameters.

Abstract. A sensitive and simple method for high-performance liquid chromatography (HPLC) determination of traces of chromium species in lake …

The effect of diluent on the extraction of chromium with amide was investigated. • The diluents can affect extraction performance, extracted complex, and thermodynamics. • FT-IR spectra and UV–Vis spectra under different diluents were compared. • The diluent can affect the reaction site of the amide extractant and change …

Extraction of chromium with the TritonX-100 concentration was investigated within the range of 0.1–6.0 ... the concentration of TritonX-100 was chosen as 3.0 g L −1 in order to achieve the optimal surfactant concentration in conjunction with the highest possible extraction efficiency. Download : Download full-size image; Fig. 2.

A synergistic solvent extraction method for recovering chromium (III) was proposed using the mixed extractant consisting of di (2-ethylhexyl) phosphoric acid (D2EHPA) and isooctanol. Based on the ...

The extraction efficiency for chromium was 86.3% after the 48-h extraction. In the case of arsenic extraction, effective removal was achieved with 3:1 diluted solution after the 36-h extraction and with undiluted solution after the 24-h extraction. The extraction efficiency for chromium was 92.7% with undiluted solution after the 48-h ...

The extraction ratio of chromium roasted by microwave irradiation increased from 4.75% to 7.35% and then slightly decreased to 3.62% for roasting temperatures from 300 °C to 600 °C and up to 1000 °C. Similarly, the extraction ratio of chromium roasted by muffle furnace increased from 3.67% to 6.51% and then slightly decreased to 2.16% for ...

Solvent extraction system for removal of Cr (VI) from acidic aqueous solutions with trioctylamine in toluene was developed in a microreactor operating in slug …

Extraction. Chromite ( FeCr2O4 FeCr 2 O 4) is the most commercially useful ore, and is extensively used for extraction of chromium. Chromium is produced in two forms: Ferrochrome by the reduction of chromite with …

The solvent extraction of hexavalent chromium from acidic aqueous solutions by trioctylamine has been developed in a slug flow microreactor to resolve some drawbacks of conventional contactors. The employed microreactor had a T-shaped junction and a circular microchannel with an inner diameter of 0.7 or 1.0 mm. Excellent …

The results of bench-scale laboratory tests and in situ, pilot-scale demonstration of electrokinetic extraction of chromium and cadmium from contaminated soil are presented. The laboratory tests were conducted using 10 cm long samples under current density of 5 A/m 2 for 1200 h. Tests were conducted with and without citric acid …

1. Introduction. Membrane extraction technology with simultaneous extraction and stripping has attracted much attention in the field of separation due to its high selectivity, greenness, and energy saving [1], [2]pared with supported liquid membranes, polymer inclusion membrane (PIM) has emerged as the most promising …

4. Conclusions. The finding showed that PGPR inoculation with plants (P. putida) increased plant growth and metal uptake, however microbe-assisted phytoremediation enhance the Cr accumulation and reclaim the Cr toxic soils.Our study demonstrated that the growth promoting effect of PGPR having ACCD activity was …

Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr 2 O 3 cannot be extracted after chromite sodium roasting and remains in COPR, wasting valuable Cr resources. In this study, Mg was selectively removed by using (NH 4) 2 SO 4 roasting in …

Conventional vanadium (V) extraction methods for vanadium-bearing slags create high chromium content discharge Cr(VI)-containing hazardous wastes. In this article, an ecofriendly magnesiation roasting-acid leaching method is proposed to selectively extract V from the slag. In the near-zero discharge process the generation of Cr(VI) is …

Generally, extraction of Cr(VI) using calixarenes offers two advantages: one is the stability of the aromatic core structure, which can effectively avoid oxidation of …

Table 4 also shows that the attempts at extraction of Cr (III) using LiFDDC did not result in any detectable amounts of chromium. The poor extraction of 5 ppm Cr (VI) probably has more to do with a limiting reagent situation. The NIST 1-ppm Cr (VI) standard sample was recovered at 88.4±2.91%. Table 4.

VCRS is considered hazardous waste owing to the significant amount of heavy metals it contains, including carcinogenic hexavalent chromium. As shown in Fig. 1, VCRS is mainly generated from the wastewater produced during vanadium production using chromium-bearing vanadium slag.During the wastewater treatment, VCRS is obtained …

The best conditions, yielding a chromium recovery of about 92%, were a time of 60 min, a temperature of 60 °C and 2.1 mol/L peroxide. Additional essays revealed that the same result could be obtained with more economic conditions (40 min, 1.4 mol/L peroxide and 60 °C). This technique proved not only effective in comparison with existing ...

Introduction. Minerals are essential nutrients for the body and chromium is one of them. Cr with symbol "Cr" with a molecular weight of 51.9961 +/- 0.0006 u occupying allotted space number 24 in Mendeleev table [].Out of all forms of Cr compounds, trivalent Cr is the most stable form in a biological system and found in food, and hexavalent is a …

One of the difficulties in performing speciation analyses on solid samples is finding a suitable extraction method. Traditional methods for extraction of hexavalent chromium, Cr(VI), in soils, such as SW846 Method 3060A, can be tedious and are not always compatible with some determination methods. For example, the phosphate and …

Chromium was reclaimed from electroplating sludge using intermediate temperature roasting-sodium oxidization method.Single factor experiments were done on the major factors affecting the reclamation of chromium,which included roasting temperature,roasting time,ratio of sludge and sodium carbonate and extraction time.Through the orthogonal …

In the present work an attempt has been made to extract Cr (VI) through emulsion liquid. surfactant membrane (or, emulsion liqui d membrane-ELM) from it's acidic solution using alamine-336 and ...

Based on the previous investigation, Li et al. . proposed asynchronous extraction of vanadium and chromium by stepwise sodium roasting-water leaching to accomplish the separation of vanadium and chromium in V-Cr slag. The overall extractions of vanadium and chromium are 98.9 and 96.6%, respectively. However, as reported by …