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Improvement of Technological Modes of Electrodialysis Apparatus for Treatment of Chromium-Containing Waste Waters

Mkheidze Nino, Gotsiridze Raul, Kontselidze Lamzira, Mkheidze Svetlana, Davitadze Ruslan

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 5

47--54

EN

The wastewaters of galvanizing plants contain toxic heavy metals, which causes pollution of the environment and endangers it. The aim of the present study includes concentration of chromium (VI) ions from chromium plating wastewaters, purification of wastewater and its reuse for development of waste-free technological cycle. This study was carried out with the pilot electrodialysis apparatus designed by the authors and produced in the Institute engineering workshop using real plating rinse water of the plating shop. The authors obtained desalinated water which may be recirculated in rinsing bath and chromium salts concentrate that can be applied in chromium plating bath after correction. As a result of the conducted experiment, the ion-exchange membranes resistant to "poisoning" with chromium (VI) ions and stable in the process of regeneration were selected and the technological modes for stable operation of apparatus matched.

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Adsorption of Chromium (VI) on Raw and Modified Carpathian Diatomite

Puszkarewicz Alicja, Kaleta Jadwiga

Journal of Ecological Engineering

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2019

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Vol. 20, nr 7

11--17

EN

The paper presents the research on the usability of natural Carpathian diatomite for removing chromate ions from water solutions. The concentration of chromium (VI) in test water was C0 = 1 g/m3. Both raw diatomite and the diatomite modified with iron compounds of granulation 0.5–1.0 mm were tested. The process kinetics, as well as the effect of water reaction and the diatomite type on chromium sorption were determined under static conditions (no through flow). For both diatomite types, the chromium adsorption proceeded most effectively at pH 4. The effect of diatomite modification with iron compounds on the effectiveness of chromium (VI) adsorption was determined on the basis of Freundlich adsorption isotherm. Compared to raw diatomite, the modified adsorbent (diatomite-Fe) exhibited great sorption capacity for chromate ions from water. When applied under dynamic conditions (v = 4 m/h), as filtration bed, it removed chromium compounds from water very effectively. It makes diatomite-Fe material a promising candidate for application in water treatment systems. The chromium concentration in the effluent oscillated within Ck = 0.001–0.002 mg/dm3, and the adsorption capacity of the bed, determined in the bed breakthrough point, reached Pp = 316.8 mg/kg.

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Efektywność usuwania chromu(VI) z roztworów wodnych w procesie wymiany jonowej

Puszkarewicz A., Kaleta J., Papciak D.

Przemysł Chemiczny

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2013

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T. 92, nr 6

1083--1086

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Removal of chromium from aqueous solutions using Derris indica wood based activated carbon. Adsorption batch studies

Ulaganathan S., Govindan V.

Environment Protection Engineering

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2013

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Vol. 39, nr 3

21--29

EN

Adsorption efficiency in removal of chromium from waste water has been studied using Derris indica based activated carbon by conducting batch adsorption tests. Adsorption kinetics of chromium removal by Derris indica was examined by varying factors such as pH and concentration of synthetic solution and dosage of activated carbon. It has been found that the Derris indica based activated carbon is able to remove 80 mg/dm3 of chromium from aqueous solution by dosage of 0.8 g/150 cm3 with optimum contact time of 15 min. The isotherm data confirms with both Langmuir and Freundlich isotherm forms.