Thermally induced transformations of Fe oxide-stabilized residues from waste incineration

2001 ◽  
Vol 65 (5) ◽  
pp. 635-643 ◽  
Author(s):  
M. A. Sørensen ◽  
C. Bender Koch
Keyword(s):  
Heavy Metals ◽  
Room Temperature ◽  
Waste Incineration ◽  
Oxide Phase ◽  
Waste Incinerator ◽  
Air Pollution Control ◽  
Fe Oxide ◽  
Thermally Induced ◽  
Co Precipitation ◽  
Reducing Gases

AbstractAir pollution control (APC) facilities at waste incinerator plants produce large quantities of solid residues rich in salts and heavy metals. Heavy metals are readily released to water from the residues and it has, therefore, been found suitable to apply a rapid co-precipitation/adsorption process as a means to immobilize the toxic elements. In the ‘Ferrox process’, this immobilization is based on co-precipitation with an Fe(III) oxide formed by oxidation of Fe(II) by air in an aqueous slurry with the APC residue at alkaline pH. In this work we have undertaken a Mössbauer spectroscopy study of the Fe oxide phase formed by precipitation at room temperature and of the oxides present after heating to 600 and 900°C. The only Fe oxide observed in the Ferrox product at room temperature is a very poorly crystalline ferrihydrite. Analytical transmission electron microscopy showed that the main elements associated with the ferrihydrite are Si and Ca. Following heating to 600°C the oxide is still characterized as an amorphous Fe oxide, and it is probable that Si associated with the ferrihydrite is decisive in preventing crystallization. After the 900°C treatment a transformation into defect maghemite is observed. Reducing gases produced from carbon in the samples probably induces this transformation. It eases, thus, the reduction of Fe(III) and the consequent formation of magnetite that eventually oxidizes to maghemite during cooling in air.

Analysis of Construction Material Using SEM (Scanning Electron Microscope)

2013 ◽  
Vol 677 ◽  
pp. 145-148
Author(s):  
Hai Ying Zhang ◽  
Chuan Yun Wan
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Pollution Control ◽  
Room Temperature ◽  
Construction Material ◽  
Material Structure ◽  
Heating Process ◽  
Air Pollution Control ◽  
Change Of Microstructure ◽  
Electronic Microscope

This study analyzed change of microstructure of air pollution control (APC) ash after being sintered at 700°C, 900°C and 1100°C using SEM (scanning electronic microscope). It was found that fly ash has a loose structure and lots of pores among the particulates, making it easy for heavy metals to be extracted into the environment. Lots of glass phases exist in it, which improves activity of the ash using as a construction material. Structure of fly ash is strengthened with increase of temperature, which is conducive to stabilization of heavy metals. Crystal content increases from room temperature to 900°C and then decreases in the heating process, while content of glass phases has a reverse trend.

Removal of Formaldehyde Using Mn-Ce-Fe Oxide Catalyst

2013 ◽  
Vol 634-638 ◽  
pp. 567-570
Author(s):  
Hai Zhao ◽  
Ke Jian Han ◽  
Yao Tong ◽  
Xiao Qi Sha ◽  
Yang Yang Li
Keyword(s):  
Room Temperature ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Fe Oxide ◽  
X Ray ◽  
Surface Areas ◽  
Transmission Electron ◽  
Co Precipitation

Mn-Ce-Fe Oxide catalysts were prepared by a co-precipitation method using precipitants NH4OH. The catalysts were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and sSubscript textuperior catalytic performance at room temperature. The catalysts would reduce substantially indoor formaldehyde concentrations in the present of airstreams.

scholarly journals Mechanical Properties of Municipal Solid Waste Incinerator (MSWI) Bottom Ash as Alternatives of Subgrade Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Yucheng Huang ◽  
Ji Chen ◽  
Shenjie Shi ◽  
Bin Li ◽  
Jialin Mo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Rapid Development ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Treatment Method ◽  
Waste Incinerator ◽  
Air Pollution Control ◽  
Mswi Bottom Ash

The rapid development of industrialization, urbanization, and population of the society augments the rising amount of municipal solid waste (MSW). With the advantage of considerably reducing mass and volume of solid wastes and generating energy, the incineration is a widely used treatment method for MSW. During the incineration process, the organic substances contained in the wastes are combusted, and the massive residues are remained. Of the incineration residues, bottom ash takes up to 80–90%, and the remainders are fly ash along with air pollution control residues. Dealing with the municipal solid waste incineration (MSWI) bottom ash in a sustainable manner is the primary principle. Significantly, MSWI bottom ash has been successfully utilized in diverse beneficial applications in recent decades, especially in civil engineering applications. This paper investigates the mechanical properties and validity of MSWI bottom ash as applicable substitutes of conventional subgrade materials. For this reason, a series of direct shear and CBR tests are performed on specimens with different water contents and dry densities.

Determination and Distribution of Heavy Metals in the Municipal Waste Incinerator Slags from Guangdong Province

2011 ◽  
Vol 55-57 ◽  
pp. 229-232
Author(s):  
Jin Yong Liu ◽  
Shui Yu Sun ◽  
Rong Xue Zhang ◽  
Sheng Zhong
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Particle Size ◽  
Small Particle ◽  
Guangdong Province ◽  
Waste Incineration ◽  
Quality Standards ◽  
Waste Incinerator ◽  
Particle Sizes ◽  
Municipal Waste Incinerator

The content of heavy metals (Cu, Cr, Cd, Pb, Zn and Ni) was determined by Atomic absorption spectrophotometer (AAS) and their distributions were analyzed in various waste incineration slags. The results showed that the particle size less than 5mm were a major component in the slag, which were about 59.42% in all the incineration slags. The content of heavy metals was different in the incineration slags. The content of heavy metals Zn, Cr and Cu were significantly higher than that of other heavy metals and that of Pb was in second, followed by Ni, and that of Cd was in the least. The contents of these heavy metals were higher than that of the soil environmental quality standards (GB15618-1995) and the background values in soil of Guangdong. The distribution of heavy metals in different particles of the slag were very different, in which the content of Cr, Zn, Cd and Ni were higher in the small particle sizes, but that of Cu and Pb was not obvious in various particles. In all, the content and distribution of heavy metals were mainly with composition of the waste and the heavy metal characteristics.

The fate of heavy metals and salts during the wet treatment of municipal solid waste incineration bottom ash

2021 ◽  
Vol 121 ◽  
pp. 33-41
Author(s):  
Yanjun Hu ◽  
Lingqin Zhao ◽  
Yonghao Zhu ◽  
Bennong Zhang ◽  
Guixiang Hu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration

A mini-review of heavy metal recycling technologies for municipal solid waste incineration fly ash

2021 ◽  
pp. 0734242X2110039
Author(s):  
Huan Wang ◽  
Fenfen Zhu ◽  
Xiaoyan Liu ◽  
Meiling Han ◽  
Rongyan Zhang
Keyword(s):  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Electrochemical Process ◽  
Chemical Extraction ◽  
Air Pollution Control ◽  
Municipal Solid Waste Incineration ◽  
Mswi Fly Ash ◽  
Metal Recycling

This mini-review article summarizes the available technologies for the recycling of heavy metals (HMs) in municipal solid waste incineration (MSWI) fly ash (FA). Recovery technologies included thermal separation (TS), chemical extraction (CE), bioleaching, and electrochemical processes. The reaction conditions of various methods, the efficiency of recovering HMs from MSWI FA and the difficulties and solutions in the process of technical development were studied. Evaluation of each process has also been done to determine the best HM recycling method and future challenges. Results showed that while bioleaching had minimal environmental impact, the process was time-consuming. TS and CE were the most mature technologies, but the former process was not cost-effective. Overall, it has the greatest economic potential to recover metals by CE with scrubber liquid produced by a wet air pollution control system. An electrochemical process or solvent extraction could then be applied to recover HMs from the enriched leachate. Ongoing development of TS and bioleaching technologies could reduce the treatment cost or time.

Comparison of trace element mobility from MSWI ash before and after plasma vitrification

2021 ◽  
pp. 0734242X2110115
Author(s):  
Wesley N Oehmig ◽  
Justin Roessler ◽  
Abdul Mulla Saleh ◽  
Kyle A Clavier ◽  
Christopher C Ferraro ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Waste To Energy ◽  
Air Pollution Control ◽  
Plasma Arc ◽  
Municipal Solid Waste Incineration ◽  
Trace Element Mobility ◽  
Before And After ◽  
Air Pollution Control Residues

A common perception of plasma arc treatment systems for municipal solid waste incineration ash is that the resulting vitrified slag is inert from an environmental perspective. Research was conducted to examine this hypothesis and to assess whether reduced pollutant release results from pollutant depletion during the process of the ash with plasma, or encapsulation in the glassy vitrified matrix. The concentrations of four discrete municipal solid waste incineration ash samples before and after plasma arc vitrification in a bench-scale unit were compared. Slag and untreated ash samples were leached using several standardized approaches and mobility among the four metals of interest (e.g. As, Cd, Pb and Sb) varied across samples, but was generally high (as high as 100% for Cd). Comparison across methods did not indicate substantial encapsulation in the vitrified slag, which suggests that reduced pollutant release from plasma arc vitrified slag is due to pollutant depletion by volatilization, not encapsulation. This has significant implications for the management of air pollution control residues from waste-to-energy facilities using plasma arc vitrification.

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