scholarly journals Bacterially generated Fe2(SO4)3 from pyrite, as a leaching agent for heavy metals from lignite ash

2007 ◽  
Vol 72 (6) ◽  
pp. 615-619 ◽  
Author(s):  
Jelena Jekic ◽  
Vladimir Beskoski ◽  
Gordana Gojgic-Cvijovic ◽  
Mirjana Grbavcic ◽  
Miroslav Vrvic
Keyword(s):  
Heavy Metals ◽  
Environmental Protection ◽  
Coal Combustion ◽  
Shake Flask ◽  
Metal Leaching ◽  
Testing Technique ◽  
Leaching Experiment ◽  
Leaching Efficiency ◽  
Oxidation Agent ◽  
Ash Leaching

Investigations of heavy metals from lignite ash, which is a coal combustion by-product, have for years been very interesting from different aspects of environmental protection. In this study, the possibility of microbiological ash leaching, with a strong oxidation agent, bacterially generated Fe2(SO4)3 was investigated in order to minimize the concentration of toxic ash elements. Leaching experiment by the shake flask testing technique was performed during a period of 20 d at a temperature of 28?C. The results obtained show 5- to 22-fold (for Cd and Ni approx. 5, Zn approx. 6, Mn approx. 8, Cr approx. 13 and Cu approx. 22) higher metal leaching efficiency in the suspension with bacterially generated Fe2(SO4)3 than in the control suspension. .

Separation of Cd(ii) and Ni(ii) in a binary mixture through competitive adsorption and acid leaching

RSC Advances ◽  
2015 ◽  
Vol 5 (113) ◽  
pp. 92885-92892 ◽  
Author(s):  
Hong Guo ◽  
Shufen Zhang ◽  
Zinong Kou ◽  
Shangru Zhai ◽  
Wei Ma ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Binary Mixture ◽  
Aqueous Solutions ◽  
Environmental Protection ◽  
Competitive Adsorption ◽  
Acid Leaching

Different heavy metals present simultaneously in aqueous solutions should be separated to promote environmental protection.

scholarly journals The Impact of Changing Environmental Conditions on the Retention of Heavy Metals Adsorbed by Pine Bark

2017 ◽  
pp. 278-284
Author(s):  
Oleksandr Khokhotva
Keyword(s):  
Heavy Metals ◽  
Environmental Conditions ◽  
Metal Removal ◽  
High Capacity ◽  
Pine Bark ◽  
Urea Solution ◽  
Metal Leaching ◽  
Total Efficiency ◽  
Runoff Water ◽  
The Impact

Landfills are widely used for the disposal of households' and industrial waste. Liquid landfill effluents contain heavy metals, are toxic to humans and ecosystems and have to be efficiently treated. One treatment option that is becoming popular is the reactive filter technology. The total efficiency of metal removal by a filter media greatly depends not only on adsorption itself, but also on the metal leaching from the adsorbent. The last parameter, in turn, may be dependant on changing environmental conditions since filters are usually located on open air and flow of contaminated water (landfill leachate, runoff water) has the intermittent nature. A filter material may dry, become frozen or stay wet, depending on a season. Previously adsorbed metals can leach from an adsorbent at the next flash of water, coming to water treatment facilities. Among others, pine bark has shown a high capacity to adsorb heavy metals from landfill leachates. In this study, pine bark has been pre-treated with urea-solution in order to increase its stability and adsorption properties. Within leaching experiments using either non-treated or pre-treated bark samples no significant influence of the changing environmental conditions on the extent of metal leaching was observed, though in most cases, metal leaching from wet bark samples exposed to freezing was somewhat higher. Zn leaching was the highest and Cu leaching the lowest for both NTB and UTB samples. The metal leaching from non-treated bark was several-fold higher compared to urea-treated bark. Possible mechanisms of barkurea interactions and reasons for enhanced metals adsorption by urea-modified bark are discussed.

scholarly journals Use of Sewage Sludge in Agriculture

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Daniela CIUPEANU CĂLUGĂRU
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Environmental Protection ◽  
Environmental Quality ◽  
Wastewater Treatment Plants ◽  
Biological Sludge ◽  
The Law ◽  
High Degree

For turning to a high degree of favorability of sludge from wastewater treatment plants, currently the reintroduction in the natural circuit of this waste is an urgent priority. Knowing precisely the composition of chemical and biological sludge from waste water in accordance with the law and the rules of their application, along with modern wastewater treatment appropriate technologies play a key role on environmental protection. Involvement by precise rules, the content of heavy metals in relation to the maximum permitted by law, translate in to particularly advantageous results in terms of environmental quality.

Application and Efficiency Verification of Classical and Unconvetional Sorbents which Serve for Capture of Heavy Metals during Coal Combustion in Experimental Fluid Device

2012 ◽  
Vol 260-261 ◽  
pp. 302-306
Author(s):  
Ondřej Němček ◽  
Stanislav Honus ◽  
Dagmar Juchelková
Keyword(s):  
Heavy Metals ◽  
Coal Combustion ◽  
Pyrolysis Process ◽  
Laboratory Equipment ◽  
Active Coal ◽  
Fluid Layers ◽  
Alternative Materials ◽  
Emission Limits ◽  
Two Fluid ◽  
Experimental Fluid

The publication is engaged in the issue of individual sorbents efficiency during the sorption of heavy metals contained in the burnt gases from the brown coal. Used sorbents for experiments are active coal and semi coke created by pyrolysis process. The process of heavy metals sorption was tested at the vertical laboratory equipment that consists of the two fluid layers that are arranged serially. Within the actual issue in the area of emission limits, the research has been focused on arsenic and mercury sorption. The obtained samples were analysed at the laboratory and consequently, their efficiency was evaluated. The aim of the article is to find out a suitable methodologies and respective alternative materials to be used within the industrial production.

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