Application of solar thermal desorption to remediation of mercury-contaminated soils

Navarro, Andrés; Cañadas, Inmaculada; Martı́nez, Diego; García, José Rodríguez; Mendoza, José Luis Hernández

doi:10.1016/j.solener.2009.03.013

Cited by 47 publications

(28 citation statements)

References 23 publications

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“…Only R 2 exhibited a positive G. O'Neil et al [41] already reported that, for similar operating conditions, the formation of metallic Hg from HgO in the gas phase is not expected. The high value obtained for the equilibrium constant of reaction R 4 is in agreement with previous results reported by Navarro et al [50]. Enthalpy values ( H) reveal that reactions R 1 and R 4 are exothermic while the other reactions are endothermic.…”

Section: Thermodynamic Analysis Of the Reaction Schemesupporting

confidence: 92%

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An investigation on the modelling of kinetics of thermal decomposition of hazardous mercury wastes

Busto

Peralta

Cabrera

et al. 2013

Journal of Hazardous Materials

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h i g h l i g h t s• A reaction mechanism of thermal treatment of hazardous mercury waste is postulated.• The kinetic model for the thermal decomposition of mercury solid waste is deduced.• A methodology to investigate reaction order models in solid systems is proposed.• The thermal decomposition of mercury waste is described by two modelling approaches. a r t i c l e i n f o t r a c tThe kinetics of mercury removal from solid wastes generated by chlor-alkali plants were studied. The reaction order and model-free method with an isoconversional approach were used to estimate the kinetic parameters and reaction mechanism that apply to the thermal decomposition of hazardous mercury wastes. As a first approach to the understanding of thermal decomposition for this type of systems (poly-disperse and multi-component), a novel scheme of six reactions was proposed to represent the behaviour of mercury compounds in the solid matrix during the treatment. An integration-optimization algorithm was used in the screening of nine mechanistic models to develop kinetic expressions that best describe the process. The kinetic parameters were calculated by fitting each of these models to the experimental data. It was demonstrated that the D 1 -diffusion mechanism appeared to govern the process at 250• C and high residence times, whereas at 450 • C a combination of the diffusion mechanism (D 1 ) and the third order reaction mechanism (F 3 ) fitted the kinetics of the conversions. The developed models can be applied in engineering calculations to dimension the installations and determine the optimal conditions to treat a mercury containing sludge.

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Section: Thermodynamic Analysis Of the Reaction Schemesupporting

confidence: 92%

“…A quantification of the total mercury removal was conducted at different temperatures, 250, 350 and 450 • C, and reaction times, 5,10,15,20,25,30,40,50,60,90, 120 and 150 min.…”

Section: Thermal Treatmentmentioning

confidence: 99%

An investigation on the modelling of kinetics of thermal decomposition of hazardous mercury wastes

Busto

Peralta

Cabrera

et al. 2013

Journal of Hazardous Materials

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“…Also, SEM observations showed several small particles containing both Hg and Cl that may be associated to calomel (Hg 2 Cl 2 ). Moreover, some particles containing both Hg and Br were observed and may be associated to kuzminite (Hg 2 (Br,Cl) 2 ) (Navarro et al 2009b;Navarro et al 2012). Additionally, main minerals in the gangue were quartz, barite and silicates.…”

Section: F I G U R E 3 T O T a L Me T A L C O N C E N T R A T I O Nmentioning

confidence: 99%

Geochemistry and environmental threats of soils surrounding an abandoned mercury mine

Bori

Vallès

Navarro

et al. 2016

Environ Sci Pollut Res

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The closure of mercury mining areas is generally associated with a release of Hg and other metals into the environment due to the abandonment of mining wastes. Because of their potential toxic properties, the mobilization of particulate and soluble metal species is of major concern. In the present study, the environmental risks posed by soils surrounding an abandoned mercury mining area in Valle del Azogue (Almeria, Spain) are assessed through the determination of physical-chemical parameters, the quantification of metal concentrations, and the application of aquatic and terrestrial ecotoxicity bioassays. Chemical analysis of soil samples revealed concentrations of Hg, As, Ba, Pb, Sb, and Zn above international intervention values. Results from terrestrial tests showed detrimental effects in all studied organisms (Eisenia foetida, Folsomia candida, and different plant species) and revealed the avoidance response of earthworms as the most sensitive endpoint. Surprisingly, the most toxic samples were not the ones with higher metal contents but the ones presenting higher electrical conductivity. Aquatic ecotoxicity tests with Vibrio fischeri, Raphidocelis subcapitata, Daphnia magna, and Danio rerio were in accordance with terrestrial tests, confirming the need to couple environmental chemistry with ecotoxicological tools for the proper assessment of metal-contaminated sites. In view of the results, a remediative intervention of the studied area is recommendedPostprint (author's final draft

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“…Previous experiments of solar thermal desorption using a fluidized bed kiln showed that when soils and mine wastes were heated to 400-500 °C, the mercury removal was significant [15]. The main objective of this research was to evaluate the potential of solar thermal desorption (STD) for the removal of mercury from mining contaminated soils and wastes.…”

Section: Open Accessmentioning

confidence: 99%

Thermal Treatment of Mercury Mine Wastes Using a Rotary Solar Kiln

2014

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Thermal desorption, by a rotary kiln of mercury contaminated soil and mine wastes, has been used in order to volatilize mercury from the contaminated medium. Solar thermal desorption is an innovative treatment that uses solar energy to increase the volatility of contaminants, which are removed from a solid matrix by a controlled air flow system. Samples of soils and mine wastes used in the experiments were collected in the abandoned Valle del Azogue mine (SE, Spain), where a complex ore, composed mainly of cinnabar, arsenic minerals (realgar and orpiment) and stibnite, was mined. The results showed that thermal treatment at temperatures >400 °C successfully lowered the Hg content (2070-116 ppm) to <15 mg kg. The lowest values of mercury in treated samples were obtained at a higher temperature and exposition time. The samples that showed a high removal efficiency (>99%) were associated with the presence of significant contents of cinnabar and an equivalent diameter above 0.8 mm.

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Application of solar thermal desorption to remediation of mercury-contaminated soils

Cited by 47 publications

References 23 publications

An investigation on the modelling of kinetics of thermal decomposition of hazardous mercury wastes

An investigation on the modelling of kinetics of thermal decomposition of hazardous mercury wastes

Geochemistry and environmental threats of soils surrounding an abandoned mercury mine

Thermal Treatment of Mercury Mine Wastes Using a Rotary Solar Kiln

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