Effects of ferric ion on bioleaching of heavy metals from contaminated sediment

2003 ◽  
Vol 48 (8) ◽  
pp. 151-158 ◽  
Author(s):  
S.Y. Chen ◽  
J.G. Lin ◽  
C.Y. Lee
Keyword(s):  
Heavy Metals ◽  
Ferric Ion ◽  
Contaminated Sediment ◽  
Practical Application ◽  
Slow Kinetics ◽  
Removal Of Heavy Metals ◽  
Sulfur Oxidizing ◽  
Sediment Ph ◽  
Kinetics Of ◽  
Metal Solubilization

Bioleaching is one of the promising procedures for removal of heavy metals from contaminated sediments. The advantages of this biotechnology are that it is easy, efficient, less costly and friendly to the environment. However, the principal disadvantage of this process is its slow kinetics in metal solubilization, which may limit practical application of the bioleaching process. In order to enhance the rate and efficiency of metal solubilization, the ferric ion was used as a catalytic agent in the bioleaching process. It was found that the sediment pH apparently decreased in the bioleaching after addition of ferric ion. The metal solubilization increased quickly after the addition of ferric ion. The rate of metal solubilization was enhanced by the addition of ferric ion, especially for Cr and Pb. An increase in the amount of ferric ion added increased the final efficiency of metal solubilization. The highest final efficiency of metal solubilization was obtained in the bioleaching with 1 g/L of ferric ion. Besides, the growth of sulfur-oxidizing bacteria was not affected by addition of ferric ion in the bioleaching. It was concluded that the kinetics of metal solubilization were enhanced by addition of ferric ion in the bioleaching process.

Factors affecting bioleaching of metal contaminated sediment with sulfur-oxidizing bacteria

2000 ◽  
Vol 41 (12) ◽  
pp. 263-270 ◽  
Author(s):  
S. Y. Chen ◽  
J. G. Lin
Keyword(s):  
Heavy Metals ◽  
Solid Content ◽  
Bacterial Activity ◽  
Optimum Concentration ◽  
Contaminated Sediment ◽  
Sulfur Concentration ◽  
Factors Affecting ◽  
Sulfur Oxidizing ◽  
Ph Dependent ◽  
Metal Solubilization

Bioleaching is one of the feasible methods for the treatment of sediments contaminated with heavy metals. Effects of solid content, substrate (sulfur) concentration and pH on the performance of bioleaching process were investigated in this study. It was found that rates of sediment acidification and metal solubilization decreased with increasing solid content. Besides, sulfur concentration greater than 5 g/l was found to be inhibitory to bacterial activity and metal solubilization from sediment. It was concluded that a substrate concentration of 5 g/l in reactor was the optimum concentration for bioleaching process. It was also observed that solubilization of heavy metal from the sediment was highly pH-dependent. For all values of solid content and sulfur concentration tested, the efficiency of metal solubilization from sediment followed the order Cu>Zn>Pb>Cr.

Study of the Cu(II) removal from aqueous solutions by adsorption on titania

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Toxic Metals ◽  
Low Cost ◽  
Lateral Interaction ◽  
Tio2 Surface ◽  
High Toxicity ◽  
Removal Of Heavy Metals ◽  
Solution Parameters ◽  
Kinetics Of

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.

Nitrogen doped porous carbon fiber/vertical graphene as efficient polysulfide conversion catalyst for high performance lithium sulfur batteries

2021 ◽  
Author(s):  
junsheng lin ◽  
Yangcheng Mo ◽  
Shiwen Li ◽  
Jie Yu
Keyword(s):  
High Performance ◽  
Practical Application ◽  
Nitrogen Doped ◽  
High Sulfur Content ◽  
Slow Kinetics ◽  
Lithium Sulfur Batteries ◽  
Conversion Catalyst ◽  
Kinetics Of ◽  
Lithium Sulfur ◽  
High Sulfur Loading

Under high sulfur loading, high sulfur content and low electrolyte/sulfur ratio (E/S), the practical application of lithium sulfur (Li–S) batteries is seriously limited by the negative and slow kinetics of...

Heavy metal removal from wastewater and leachate co-treatment sludge by sulfur oxidizing bacteria

2001 ◽  
Vol 44 (10) ◽  
pp. 53-58 ◽  
Author(s):  
L. C. Aralp ◽  
A. Erdincler ◽  
T. T. Onay
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Heavy Metal Concentration ◽  
Organic Content ◽  
Removal Of Heavy Metals ◽  
Sulfur Oxidizing ◽  
Sulfur Oxidizing Bacteria

Heavy metal concentration in sludge is one of the major obstacles for the application of sludge on land. There are various methods for the removal of heavy metals in sludge. Using sulfur oxidizing bacteria for microbiological removal of heavy metals from sludges is an outstanding option because of high metal solubilization rates and the low cost. In this study, bioleaching by indigenous sulfur oxidizing bacteria was applied to sludges generated from the co-treatment of municipal wastewater and leachate for the removal of selected heavy metals. Sulfur oxidizing bacteria were acclimated to activated sludge. The effect of the high organic content of leachate on the bioleaching process was investigated in four sets of sludges having different concentrations of leachate. Sludges in Sets A, B, C and D were obtained from co-treatment of wastewater and 3%, 5%, 7% and 10% (v/v) leachate respectively. The highest Cr, Ni and Fe solubilization was obtained from Set A. Sulfur oxidizing bacteria were totally inhibited in Set D that received the highest volume of leachate.

Kinetics of Heavy Metals Adsorption on Gravels Derived From Subsurface Flow Constructed Wetland

2020 ◽  
pp. 193-213
Author(s):  
Celestin Defo ◽  
Ravinder Kaur
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
Contact Period ◽  
Batch Experiments ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Adsorption Rates ◽  
Kinetics Of ◽  
Best Fit ◽  
Concentration Levels

Adsorption kinetics of Ni, Cr, and Pb on gravels collected from constructed wetland was studied at varied metal concentrations and contact period for estimating the removal of heavy metals from wastewater. Batch experiments were conducted by shaking 120 ml of metal solutions having 5 concentration levels each of Ni (1.0, 2.0, 3.5, 5.0 and 6.0 mg l-1), Cr (1.0, 2.0, 3.0, 4.5 and 6.0 mg l-1), and Pb (1.0, 3.0, 6.0, 8.0 and 12.0 mg l-1) with 50 g of gravels for as function of time. Adsorption of Ni, Cr, and Pb on gravels ranged from 34.8 to 47.2, 42.7-54.9, and 47.5-56.9%, indicating their removal in the order: Pb > Cr > Ni. Freundlich model showed a good fit for Ni and Cr (R2>0.9) while Langmuir model fitted better for Pb (R2= 0.7). The pseudo-second-order model showed the best fit to simulate the adsorption rates of these metals on gravel.

Microbial Ferrous Ion Oxidation versus Ferric Ion Precipitation at Low Temperature Conditions

2017 ◽  
Vol 262 ◽  
pp. 381-384 ◽  
Author(s):  
Emmanuel Chinonso Chukwuchendo ◽  
Tunde Victor Ojumu
Keyword(s):  
Packed Column ◽  
Ferrous Ion ◽  
Design Management ◽  
Ferric Ion ◽  
Oxidation Rates ◽  
Temperature Conditions ◽  
First Order Kinetics ◽  
Slow Kinetics ◽  
Cold Condition ◽  
Kinetics Of

Ferric ion precipitation in a typical bioleach operation is known to be inevitable. However, its management has been emphasized as critical to efficiently maximize the potential that bioleach technique offers, especially in heap bioleach systems. Although there are some studies on ferric ion precipitation, limited studies exist in the context of a cold condition which often prevails in some operations. This study investigated ferrous ion biooxidation and ferric ion precipitation under cold temperature conditions. The results showed that maximum ferrous ion oxidation rates of 1.05, 1.25, 1.51 and 1.60 mmol/L/h at 6, 7, 8 and 10°C respectively were achieved in packed column reactor. The results further showed a simultaneous ferric ion precipitation during the oxidation process. The kinetics of ferric ion precipitation follows a first order kinetics with the rate constants of 0.0066, 0.0074, 0.0080 and 0.011 h-1. Activation energies of 68 and 77 kJ/mol were obtained for both ferrous ion biooxidation and ferric ion precipitation respectively. Although slow kinetics are expected for both processes, the kinetics information may be useful for design management consideration at least to predict when bioleach liquor would likely run out of dissolved ferric ion.

Hydrogenation and Dehydrogenation Properties of Mg-Cu, Mg-Al Eutectic Alloy

2009 ◽  
Vol 1216 ◽  
Author(s):  
Ho Shin ◽  
Yuma Eto ◽  
Hiroyuki T. Takeshita ◽  
Koji Tanaka
Keyword(s):  
Eutectic Alloy ◽  
Functional Materials ◽  
Rolling Process ◽  
Sintering Process ◽  
Practical Application ◽  
Hydrogen Density ◽  
Storage Study ◽  
Major Subject ◽  
Slow Kinetics ◽  
Kinetics Of

AbstractMg has 7.6 mass% of high gravimetric hydrogen density, an abundance of resources and inexpensive price compared with other functional materials. Owing to these merits, it has been the major subject of hydrogen storage study. However, it is unsuitable for practical application due to thermodynamic stability and slow kinetics of Mg hydride. Therefore, many ways such as fabrication of nanocrystalline or addition of catalyst have been proposed to solve the problems of Mg hydride system. Copper and aluminum are inexpensive and can obtain easily as well as Mg. Each eutectic alloy could be produced by sintering process and observed improvement of reaction with hydrogen. Mg2Cu laminate, one phase of Mg-Cu eutectic alloy, could also be produced by cold-rolling process, and it showed reversible reaction with hydrogen, at this study.

Bioleaching of heavy metals from contaminated aquatic sediments using indigenous sulfur-oxidizing bacteria: a feasibility study

1998 ◽  
Vol 37 (6-7) ◽  
pp. 387-394 ◽  
Author(s):  
H. Seidel ◽  
J. Ondruschka ◽  
P. Morgenstern ◽  
U. Stottmeister
Keyword(s):  
Heavy Metals ◽  
Pilot Plant ◽  
River Sediments ◽  
Chemical Properties ◽  
Leaching Potential ◽  
Removal Of Heavy Metals ◽  
Sulfur Oxidizing ◽  
Physical And Chemical ◽  
Better Than ◽  
Sulfur Oxidizing Bacteria

The removal of heavy metals from contaminated river sediments was studied using suspension leaching under laboratory conditions and percolation leaching in a pilot plant. The leaching potential of indigenous sulfur-oxidizing bacteria was compared with acid treatment. Bioleaching with elemental sulfur as substrate was found to be better than treatment with sulfuric acid for the solubilization of all metals tested. The physical and chemical properties of the sediments used in this study did not affect leaching capacity under optimum conditions in the laboratory. Under the practical conditions in the pilot plant, the redox state of sludge had a considerable influence on leaching efficiency. In a deposited oxic sediment with good permeability, about 62% of the metals tested were removed by percolation leaching after 120 days. Zn, Cd, Ni, Co and Mn were sufficiently leached to enable treated sediments to be reused as soil. In a freshly dredged anoxic sediment, only a total of 9 % of metals were removed. The results indicate that freshly dredged sediments need to undergo pretreatment before percolation leaching to improve mass transfer and to activate the leaching active bacteria.

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