Chemical, physical and biological technologies for removal of sulphate from mine tailings pond water (8 g SO 4 2− /L) were investigated. Sulphate concentrations of approximately 1,400, 700, 350 and 20 mg/L were obtained using gypsum precipitation, and ettringite precipitation, biological sulphate reduction or reverse osmosis (RO) after gypsum pre-treatment, respectively.

The evaluation of chemical precipitation for sulfate removal such as gypsum and ettringite formation as well as the use of membrane filtration and the decision

the ettringite precipitation stage, in comparison to the other two liquid reagents. Table 4 contains the test results for the solid reagents. It is surprising to find that products based on crystalline aluminium hydroxide (Hydrargillite), even at relatively high doses, are not appropriate for ettringite precipitation. The obvious 2020-08-01 · Ettringite precipitation was implemented as an alternative to lime precipitation to process sulfate-rich brine resulting from the NF operation. More than 93% of the sulfate ions were removed by ettringite precipitation, whereas lime precipitation removed less than 28% under the same conditions due to the difference in their solubility.

Ettringite precipitation

Chemical precipitation techniques can be used to solve a number of problems in mine water treatment. Precipitation and co-precipitation are applicable for the removal of metals as hydroxides Chemical precipitation. Sulphide precipitation; Precipitation with barium salts; Ettringite precipitation; Iron co-precipitation; Ion exchange; Membrane processes; Sulphate reduction in reactors; Treatment/disposal of water treatment residues; Passive treatment technologies. Aerobic constructed wetlands; Anaerobic constructed compost wetlands The ettringite process flow diagram used for simulation is illustrated in Figure 3.

A portion of the ettringite sludge from the ettringite precipitation reactor, Reactor 3, is recycled and mixed with the feed water in the ettringite dissolution reactor, Reactor 1 to In the present study, experiments were conducted to optimize sulfate removal efficiency with ettringite precipitation from landfill leachate using Response Surface Methodology (RSM) and Central Composite Design (CCD). The statistical analysis of the results showed that the operating parameters such as molar rates of Ca/ SO4 and Al/SO4, and pH had a significant effect on sulfate removal ettringite precipitation has been found to be around 12,0 (Kabdaşlı et al., 2015). After the precipitation reaction is complete, the ettringite solids are separated from the feed water, filtered and thickened.

from the performed experimental tests with the tested mine waters that ettringite precipitation yielded in low residual concentrations in treated water.

The plant consists essentially of a raw water tank, a reactor tank followed by a (2016). Sulphate control by ettringite precipitation in textile industry wastewaters. Environmental Technology: Vol. 37, 9TH IWA SYMPOSIUM ON WASTE MANAGEMENT PROBLEMS IN AGRO-INDUSTRIES-AGRO’2014, pp. 446-451.

Ettringite was precipitated in the presence of TcO 4 –, IO 3 –, and/or CrO 4 2–, known contaminants of concern to nuclear waste treatment, over pre-determined precipitation periods. Solution analyses quantified contaminant removal, and the collected solid was characterized using bulk and microprobe X-ray diffraction coupled with pair distribution function and microprobe X-ray

Known processes for sulphate removal with ettringite precipitation contain the main unit Development stage. Known 2016-10-01 1998-11-01 2004-02-01 2019-03-05 the ettringite precipitation stage, in comparison to the other two liquid reagents. Table 4 contains the test results for the solid reagents. It is surprising to find that products based on crystalline aluminium hydroxide (Hydrargillite), even at relatively high doses, are not appropriate for ettringite precipitation… Ettringite precipitation can be applied for removal of sulfate from textile wastewater (Tunay et al., 2014), acidic mine drainage (Madzivire et al., 2010), tap 2017-07-01 Ettringite formation can also provide a polishing effect, allowing precipitation of difficult-to-remove metals such as chromium, arsenic, selenium and cadmium, often below their respective analytical detection limits. Boron, fluoride and up to 30 percent of the … The simulation of ettringite precipitation process was carried out assuming only ettringite in a solid phase. Other constituents were in liquid phase, also gibbsite and portlandite.

In the present study, experiments were conducted to optimize sulfate removal efficiency with ettringite precipitation from landfill leachate using Response Surface Methodology (RSM) and Central Composite Design (CCD). The statistical analysis of the results showed that the operating parameters such as molar rates of Ca/ SO4 and Al/SO4, and pH had a significant effect on sulfate removal efficiency. Ettringite was precipitated in the presence of TcO4-, IO3-, and/or CrO42-, known contaminants of concern to nuclear waste treatment, over pre-determined precipitation periods. Solution analyses quantified contaminant removal and the collected solid was characterized using bulk and microprobe XRD coupled with PDF and microprobe XRF more » analyses. DOI: 10.1590/0104-6632.20180353S20170528 Corpus ID: 104463417. STATISTICAL OPTIMIZATION OF ETTRINGITE PRECIPITATION IN LANDFILL LEACHATE @article{Aygun2018STATISTICALOO, title={STATISTICAL OPTIMIZATION OF ETTRINGITE PRECIPITATION IN LANDFILL LEACHATE}, author={A. Aygun and S. Dogan and M. E. Argun}, journal={Brazilian Journal of Chemical Engineering}, … ettringite precipitation Source.
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-C3S. -C2S. -C4AF. - Gypsum (CSH2) is added to the clinker. Water is added to make hydrated paste.

This process is based on the addition of aluminium hydroxide and lime at pH 11.5-12.0 resulting in precipitation of ettringite (Ca 3 Al 2 O 6 3CaSO 4 ⋅33H 2 O). By employing ettringite ettringite precipitation is a well-known process and can be described as a standard method for sulphate removal from industrial wastewater at relatively small flow (S. CHUSTER . et al., 1996).
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Ettringite precipitation can reduce the sulphate concentration to ca. 200 mg/l (concentrations < 100 mg/l have also been reported) and provides also simultaneous reduction of calcium. Ettringite formation can also provide a polishing effect, allowing precipitation of metals and metalloids such as Ni, Cd, Cu, Zn, Cr, As, Se, and Cd.

A novel sulfate removal process via ettringite precipitation was developed by dissolving ettringite and recycling Al 3+ under low pH condition. Effects of solid to liquid ratios, pH and temperature on ettringite dissolution, Al recovery and transformation of precipitates were investigated by batch experiments. ettringite precipitation is a well-known process and can be described as a standard method for sulphate removal from industrial wastewater at relatively small flow (S. CHUSTER .

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Regarding the phase development during hydration, ettringite precipitation was identified as the dominant reaction in the first two hours. For both temperatures, the increasing ettringite content turned out to correlate very well with the loss of workability of the reacting cement paste.

Help on Composition: Composition: Molecular Dec 27, 2019 Snow. Sleet. Freezing rain. A winter storm can bring a sloppy mix of the three, pile up with pure snow, or freeze everything in thick ice. from the performed experimental tests with the tested mine waters that ettringite precipitation yielded in low residual concentrations in treated water. Ettringite precipitation can reduce the sulphate concentration to ca.