A comparative study of chromium(VI) removal using sawdust and eucalyptus bark

2009 ◽  
Vol 9 (4) ◽  
pp. 343-347
Author(s):  
Abhinav Sharma ◽  
Aditya Tulsyan ◽  
Srinivas Motamarri
Keyword(s):  
Comparative Study ◽  
Hexavalent Chromium ◽  
Low Cost ◽  
Industrial Area ◽  
Contaminated Water ◽  
Tannery Effluent ◽  
Freundlich Isotherms ◽  
Chromium Vi ◽  
Experimental Parameters ◽  
Eucalyptus Bark

A comparative study on low cost biological adsorbents such as eucalyptus bark and sawdust has analyzed them for their effectiveness in the removal of hexavalent chromium. Batch experiments were carried out on synthetic solutions mimicking bore water collected from an industrial area contaminated with tannery effluent. The analysis on hexavalent chromium removal was carried out by varying experimental parameters such as pH, dosage and contact time. The study reveals that sawdust works best at pH 3 while eucalyptus shows better results at pH 2. Moreover, the optimum dosages determined for the absorbents were in compliance with the Langmuir and Freundlich isotherms. The study highlights the benefits of eucalyptus bark in purification of Cr(VI) contaminated water supply.

Breakthrough analysis for hexavalent chromium removal from drinking water in a fixed bed column

2009 ◽  
Vol 9 (6) ◽  
pp. 661-670 ◽  
Author(s):  
S. P. Dubey ◽  
K. Gopal
Keyword(s):  
Aqueous Solution ◽  
Hexavalent Chromium ◽  
Fixed Bed ◽  
Entropy Change ◽  
Spectroscopic Technique ◽  
Fixed Bed Column ◽  
Chromium Vi ◽  
Fixed Bed Adsorption ◽  
Optimal Column ◽  
Eucalyptus Bark

The activated carbon of Eucalyptus globulus was tested for their effectiveness in removing hexavalent chromium from aqueous solution using column experiments. Result revealed that adsorption of chromium(VI) on eucalyptus bark carbon was endothermic in nature. Thermodynamic parameters such as the entropy change, enthalpy change and Gibbs free energy change were found to be 1.39 kJ mol−1 K−1, 1.08 kJ mol−1 and −3.85 kJ mol−1, respectively. Different chromium concentrations were used for the fixed bed adsorption studies. The pre- and post-treated adsorbents were characterized using a FTIR spectroscopic technique. It was concluded that Eucalyptus bark carbon column could be used effectively for removal of hexavalent chromium from aqueous solution at optimal column conditions. This study showed that this biological material is potential adsorbent of Cr(VI) from water.

scholarly journals Hexavalent Chromium Removal from Groundwater—A Low-Tech Approach

2020 ◽  
Vol 2 (1) ◽  
pp. 25
Author(s):  
Samiotis Georgios ◽  
Lefteri Lefteris ◽  
Mavromatidou Charoula ◽  
Tsioptsias Costas ◽  
Trikilidou Eleni ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Low Cost ◽  
Water Bodies ◽  
Contaminated Water ◽  
Chromium Removal ◽  
Chromium Reduction ◽  
Complete Understanding ◽  
Pump And Treat ◽  
Reduction Mechanisms ◽  
The Creation

Chromium occurs in nature mainly in its trivalent or hexavalent form. Hexavalent chromium Cr(VI) is particularly toxic to humans, animals, and plants. The extensive pollution of groundwaters with Cr(VI) necessitates the complete understanding of natural chromium oxidation and reduction mechanisms, both for assessing the risk of hexavalent chromium formation and for the development of techniques for the reduction and removal of Cr(VI) from contaminated water bodies. In this work, the possibility of hexavalent chromium reduction by discarded or low-cost materials, which contain reducing compounds, is investigated regarding the creation of a compact, pump-and-treat filter for Cr(VI) removal from groundwater.

Purification of Contaminated Water with Chromium (VI) Using Pseudomonas aeruginosa

2016 ◽  
Vol 721 ◽  
pp. 143-148 ◽  
Author(s):  
Nora Noureddine ◽  
Samia Benhammadi ◽  
Fouad Kara ◽  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Hexavalent Chromium ◽  
Contact Time ◽  
Culture Broth ◽  
Contaminated Water ◽  
Toxic Heavy Metals ◽  
Initial Concentration ◽  
Chromium Vi ◽  
Batch System ◽  
Uncontaminated Soil

A bacterial strain Pseudomonas aeruginosa isolated from an uncontaminated soil has been used for the removal of hexavalent chromium (Cr (VI)). The experiments were carried out in batch system in a culture broth. The results obtained have shown that 100% of Cr (VI) are removed. Contact time, initial concentration of the hexavalent chromium, temperature, as well as the nature of the culture broth have influenced this elimination. To the initial concentration of 20g/L of Cr (VI) the elimination rates are lower, while the reverse occurs for an initial concentration of 8g/L. This study allows considering the use of Pseudomonas aeruginosa in the treatment of water polluted by toxic heavy metals such as Cr (VI).

scholarly journals Isolation of hexavalent chromium (VI) tolerant fungi from tannery effluent and their growth responses to different concentrations of chromium (VI)

2020 ◽  
Author(s):  
Soumyajit Guha ◽  
Sampa Debnath ◽  
Saswati Gayen
Keyword(s):  
Heavy Metal ◽  
Hexavalent Chromium ◽  
Morphological Characteristics ◽  
Blue Staining ◽  
Tolerance Index ◽  
Tannery Effluent ◽  
Industrial Complex ◽  
Growth Responses ◽  
Fungal Strains ◽  
Chromium Vi

The main objective of this study was to isolate, characterize, and determine chromium (VI) tolerance capacities of fungal strains from tannery effluent of the Kolkata Leather Complex area. Chromium (VI) is a heavy metal that is known to be toxic as well as carcinogenic. It is an important heavy metal widely used in various industries of which the tanning industry deserves special mention. The majority of Cr (VI) waste is discharged into the environment annually as a consequence of industrial and manufacturing activities. Kolkata Leather Complex is an industrial complex intended to serve as a central leather-tanning complex for Kolkata located at Bantala, near East Kolkata, India. Samples (tannery effluent) were collected in sterile capped tubes from Kolkata Leather Complex Area and brought to the laboratory for analysis. The samples were serially diluted and were plated on Czapekdox agar plates and incubated at 300C. After a few days, a number of morphologically different colonies were selected and sequentially subcultured for pure colony isolation on the same medium. They were preserved in the refrigerator at 40 C. Lactophenol cotton blue staining was done to observe and record the fungal morphological characteristics. They were further assessed for their hexavalent chromium tolerance capacities and subsequently the metal tolerance index was derived for each strain respectively. All 16 fungal strains isolated from the Kolkata Leather Complex tannery area were found to be chromium (VI) tolerant starting at 0.1mg/ml Cr (VI) concentration. Maximum chromium (VI) tolerance was displayed by sample S12 (2mg/ml) which was later identified as having 99.82% similarity with Aspergillus nomius strain.Keywords: effluent, fungi, heavy metal, isolation, hexavalent chromium, tannery, tolerance.

scholarly journals Cr(VI) Removal from Wastewater by Using Rice Husk Ash (RHA)

2006 ◽  
Vol 6 (1) ◽  
pp. 53
Author(s):  
M. J. Uddin ◽  
M. M.R. Khan ◽  
M S. Iftekhar ◽  
M A Islam
Keyword(s):  
Rice Husk ◽  
Optimum Parameter ◽  
Rice Husk Ash ◽  
Toxic Metal ◽  
Synthetic Wastewater ◽  
Tannery Effluent ◽  
Freundlich Isotherms ◽  
Chromium Vi ◽  
Langmuir And Freundlich Isotherms ◽  
Equilibrium Data

Rice husk ash (RHA) was studied as a potential adsorbent for Chromium (VI)removal from wastewater. RHA was able to remove effectively and economically toxic metal from synthetic wastewater. Experiments were done on the removal of Cr(VI) from dichromate solution which is a form of chromium in tannery effluent. The amount of Cr(VI) adsorption increased with the decrease in pH. The optimum parameter was = 2.0 evaluated at pH and the dose rate of the adsorbent was 5 kg RHNm3. The equilibrium data fit well in both the Langmuir and Freundlich isotherms. The study showed that 89.29 x 10-3kg Cr(VI) could be removed by 1 Kg of RHA. Since rice husk (RH) is available and cheap in Bangladesh, it can be used easily as an appropriate adsorbent to remove more than 95% Cr(VI) from tannery wastewater.

scholarly journals Hexavalent chromium reduction by ZnO, SnO2 and ZnO-SnO2 synthesized using biosurfactants from extract of Solanum macrocarpon

2021 ◽  
Author(s):  
Damian Onwudiwe ◽  
Opeyemi Oyewo ◽  
Oluwasayo Esther Ogunjinmi ◽  
Olusola Ojelere
Keyword(s):  
Hexavalent Chromium ◽  
Low Cost ◽  
Toxic Metal ◽  
Ultra Violet ◽  
Hexagonal Wurtzite Structure ◽  
Binary Oxides ◽  
Chromium Vi ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Diffraction Patterns

Abstract In this study, ZnO, SnO2 and their composite (ZnO-SnO2) were synthesized by green route using aqueous extract of Solanum macrocarpon fruit and were used for the photo-reduction of hexavalent chromium. The synthetic route involved a two-step procedure, induced by temperature via calcination at 350 and 600 ºC. The composite was prepared by the treatment of a mixture of the precursor compounds to a temperature up to 800 ºC, and the extension of the temperature to 1000 ºC, resulted in the emergence of ZnO-SnO2-ZTO. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV–vis spectroscopy. The XRD studies of the binary oxides confirmed a hexagonal wurtzite structure for the ZnO and a cubic structure for the SnO2, without any change in the diffraction patterns or supplementary diffraction peaks. The morphology of the nanoparticles indicated fairly spherical shapes for the ZnO, that tend to agglomerate with increase in temperature. The SnO2 showed rectangular shapes at both temperatures of reaction, while the ZnO-SnO2 composite showed the presence of both morphologies of the component binary oxides. In the photo-enhanced degradation study, under ultra-violet light, the effect of pH (2–8), concentration of chromium(VI) (2–8 ppm), and photocatalyst dosage (25–150 mg/L) on the reduction of Cr(VI) to Cr(III) were investigated. The reduction showed higher efficiency in acidic environment than in the alkaline environment, and also with increase in photocatalyst dosage. The composite exhibited the highest photoreduction efficiency, above 90%, at the optimum condition of pH 2, 150 mg/L photocatalyst, 2 ppm chromium solution after 90 min. These low-cost and non-toxic metal oxide and their green synthesized composite have great potentials for Cr(VI) pollution clean-up from waste water.

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