Reduction remediation of hexavalent chromium by bacterial flora in Cr(VI) aqueous solution

2010 ◽  
Vol 61 (11) ◽  
pp. 2889-2896 ◽  
Author(s):  
Qian Wang ◽  
Xinhua Xu ◽  
Fanglin Zhao ◽  
Zhihao Liu ◽  
Jinan Xu
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Low Cost ◽  
Bacterial Flora ◽  
Industrial Water ◽  
Indigenous Bacteria ◽  
Anaerobic Reactor ◽  
Priority Pollutant ◽  
Chromium Vi ◽  
Energy Conserving

Chromium(VI) is a priority pollutant in soils and wastewaters and reduction of Cr(VI) to Cr(III) is a solution to this problem. In this study a low-cost method was proposed to adapt indigenous bacteria and use them to reduce Cr(VI) in solutions. The experiment results show that Cr(VI) could be efficiently reduced by indigenous bacteria under anaerobic and pH-unadjusted conditions. After about 24 h the concentration of Cr(VI) could be reduced from 21.74 mg/L to below 0.5 mg/L. The observed Cr(VI) reduction rates were affected by temperature and pH. Cr(VI) in aqueous solutions could be reduced to Cr(III) completely and partly be incepted by the organisms. Cr(VI) reduction was enzyme-mediated. It was not an energy-conserving process but a detoxification reaction. This method could be used in an anaerobic reactor to treat low-concentration wastewater or industrial water as the last step.

Removal of Pb(II) and Cd(II) From Aqueous Solution by Adsorption Using Agrowaste-Modified Kaolinite Clay

2021 ◽  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Kaolinite Clay ◽  
Adsorbent Surface ◽  
Initial Adsorption ◽  
Adsorption Rates

This study showed that kaolinite clay modified with Moringa oleifera pods is a promising low cost adsorbent for the removal of metals from aqueous solution because the resultant composite has higher adsorption capacities, and hence a better metal ions removal efficiency. The efficiencies of these adsorbents for the removal of Pb (II) and Cd (II) ions from aqueous solutions were studied as a function of pH, time, adsorbate concentration and adsorbent dose. Adsorption results showed that pH did significantly affect removal of heavy metal ions between pH 3 and 6. Increasing contact time and initial metal ion concentration increased the sorption capacity of the adsorbent for the metal ions. Adsorbent dosage indicated mainly surface phenomena involving sharing of electrons between the adsorbent surface and the metal ion species. The adsorption of metal ions from aqueous solutions of both metal ions at different initial metal ion concentrations reduced the initial adsorption rates of the adsorption of Pb (II) and Cd (II) by unmodified and modified kaolinite clay.

scholarly journals Biosorption of Chromium (VI) and Calculations of Langmuir’s and Freundlichs Isotherms

2018 ◽  
Vol 60 (2) ◽  
pp. 90-95
Author(s):  
Muhammad Tahir Butt ◽  
Zara Amjad ◽  
Rauf Ahmad Khan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Aqueous Solution ◽  
Heavy Metal ◽  
Toxic Metals ◽  
Low Cost ◽  
Cost Effective ◽  
Environmental Applications ◽  
Chromium Vi ◽  
Yeast Biomass ◽  
Process Cost

In the present study yeast biomass has been successfully used as biosorbent for removal of Crfrom aqueous solution. Yeasts of Saccharomyces cerevisiae are effective biosorbents for heavy metal ionsand it can be bought in large quantity at low cost. S. cerevisiae can remove toxic metals from aqueoussolutions to various levels. This low-cost biosorbent will make the process cost-effective and competitiveparticularly for environmental applications in detoxifying effluents. Langmuir’s and Freundlichs isothermswere also plotted to observe the maximum biosorption of heavy metal chromium (VI).

Reduction and Biosorption of Cr from Aqueous Solution Using Banana Skin

2012 ◽  
Vol 518-523 ◽  
pp. 2708-2711 ◽  
Author(s):  
Ming Zhou ◽  
Hang Xu ◽  
Shu Fa Zhu ◽  
Ya Na Liu
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Experimental Results ◽  
Initial Concentration ◽  
Effects Of Ph

The possible use of biowaste-banana skin as an alternative, low-cost biosorbent and reductant for removal of Cr from aqueous solutions was investigated. Effects of pH, contact time, Cr(VI) initial concentration and temperature on the reduction and biosorption of Cr by banana skin were studied. Experimental results showed that 1 g of dried banana skin could reduce about 230 mg of Cr(VI) to Cr(III), at the condition of 30°C, pH 2 and 300 rpm. The maximum Qeq of Cr(III) by banana skin was 6.3mg g-1 at the Cr(VI) initial concentration of 200mg L-1, 30°C , pH 2 and 300 rpm.

Studies on the Treatment of Wastewaters Containing Cr6+ with Iron Oxide-Silica Composite Materials Prepared by Different Methods

2014 ◽  
Vol 353 ◽  
pp. 33-38
Author(s):  
Rafique Ullah ◽  
Biplob Kumer Deb ◽  
Mohammad Yousuf Ali Mollah
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Order Kinetic ◽  
Efficient Technology ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Oxide Composite ◽  
Chromium Vi

Chromium (VI) is known to be carcinogenic to humans and thus it is important to ensure the removal of Chromium (VI) from aqueous solutions and industrial effluents. The present study introduces a good alternative method for Cr (VI) removal from aqueous solutions at ambient temperature by adsorption, allowing the development of newer, lower operational cost, and more efficient technology than other processes already in use. Adsorption was found to be dependent on pH and initial concentration of Cr (VI) solution. Results of adsorption studies suggest that pristine iron oxide and silicon (IV) oxide removes 72.10% and 24.73%, respectively. The iron oxide – silicon (IV) oxide composite, prepared in this work, removes 93.88% Cr (VI) in 20 minutes from aqueous solution at an initial concentration of 50 mgL-1at pH 4.8 ± 0.2. The effect of concentration, contact time, adsorbent dose and solution pH on the adsorption of Cr (VI) were studied in detail in batch experiments. Studies of the sorption kinetics shows that equilibrium adsorption was attained in 20 minutes depending on other experimental conditions. The kinetic data justified Lagergren’s first-order kinetic equation. Adsorption isotherm study showed that the results fulfilled the Langmuir Model of adsorption isotherm. The maximum adsorption (98.28%) was recorded at pH 3 in 90 minutes for the initial Cr (VI) concentration of 50 mg L-1. Therefore, it can be concluded that iron oxide – silicon (IV) oxide composite is a potential adsorbent for adsorption of Cr (VI) from aqueous solution.

scholarly journals Polyethylenimine-functionalized cellulose aerogel beads for efficient dynamic removal of chromium(vi) from aqueous solution

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 54039-54052 ◽  
Author(s):  
Dong-Mei Guo ◽  
Qing-Da An ◽  
Zuo-Yi Xiao ◽  
Shang-Ru Zhai ◽  
Zhan Shi
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Cross Linking ◽  
Amino Groups ◽  
Chromium Vi ◽  
Cellulose Aerogel

Cellulose aerogel beads with high a density of reactive amino groups were facilely prepared via a cross-linking reaction for efficient dynamic removal of Cr(vi) from aqueous solutions.

scholarly journals Adsorption Studies of Chromium by Using Low Cost Adsorbents

Our Nature ◽  
2013 ◽  
Vol 11 (1) ◽  
pp. 11-16 ◽  
Author(s):  
N. Gandhi ◽  
D. Sirisha ◽  
K.B. Chandra Sekhar
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Contact Time ◽  
Low Cost ◽  
Water Bodies ◽  
Batch Adsorption ◽  
Toxic Heavy Metals ◽  
Adsorption Studies ◽  
Chromium Vi ◽  
Aqueous Streams

The presence of toxic heavy metals such as chromium (VI) contaminants in aqueous streams, arising from the discharge of untreated metal containing effluents into water bodies, is one of the most important environmental problems. Adsorption is one of the effective techniques for chromium (VI) removal from wastewater. In the present study, adsorbent was prepared from low cost adsorbents and studies were carried out for chromium (VI) removal. Batch adsorption studies demonstrated that the adsorbents had significant capacity to adsorb the chromium from aqueous solution. It was found that the adsorption increased with increase in contact time and adsorbent dosage. An attempt was made to study mixed algae as an adsorbent for removal of chromium (VI).DOI: http://dx.doi.org/10.3126/on.v11i1.8238 Our Nature Vol.11(1) 2013: 11-16?

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