A Study on Distribution and Characteristics of Heavy Metals and Unburned Carbon in Bottom Ash of Coal-Fired Power Plant

2014 ◽  
Vol 51 (06) ◽  
pp. 786-793
Author(s):  
Jeong Heum Nam ◽  
Min Sik Kim ◽  
Heon Chan Kang
Keyword(s):  
Heavy Metals ◽  
Power Plant ◽  
Bottom Ash ◽  
Unburned Carbon

Determination of Residual Heavy Metals in an Incinerator Bottom Ash from Municipal Solid Waste Power Plant

2020 ◽  
Vol 901 ◽  
pp. 65-71
Author(s):  
Woravith Chansuvarn
Keyword(s):  
Heavy Metals ◽  
Power Plant ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Microwave Digestion ◽  
Bottom Ash ◽  
Flame Atomic Absorption ◽  
Digestion Technique ◽  
Relative Standard ◽  
Copper Zinc

Bottom ash is a part of by-product from the municipal solid waste power plants which is always a wider problem for the urban and rural communities due to its disposal plants may cause serious environmental pollution. This work was focused on the residual heavy metal in an incinerator bottom ash from the municipal waste power plant placed in Nongkham district, Bangkok. Four bottom ash samples were obtained in 2017. After drying and grounding, the bottom ash samples were prepared to clear solution with the microwave digestion technique using nitric, hydrochloric and hydrofluoric acid under the heating program. The total residual heavy metals in the incinerator bottom ashes, such as lead, copper, zinc, and cadmium were determined by using flame atomic absorption spectrophotometer (FAAS) with deuterium background correction. The total concentration of lead, copper, zinc and cadmium were found in the range of 280.40-354.22mg kg-1, 365.35-524.45 mg kg-1, 1,527.25-2,074.34 mg kg-1, and 0.48-1.02 mg kg-1, respectively. The recovery of all metals was found in the range of 89.4-101.2% and the relative standard deviation (RSD) was to be 2.15-3.55 % (n=7). The concentration of zinc, copper, and lead was found high levels, while cadmium was low concentration. Heavy metals in solid waste material occur in different chemical forms and phases. The sample preparation based on the microwave digestion was successfully developed for the waste samples with a good reliability.

scholarly journals Reduction of Unburned Carbon Release and NOx Emission from a Pulverized Wood Pellet Boiler Retrofitted for Fuel Switching from Coal

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5077 ◽  
Author(s):  
Jiseok Lee ◽  
Seunghan Yu ◽  
Jinje Park ◽  
Hyunbin Jo ◽  
Jongkeun Park ◽  
...  
Keyword(s):  
Power Plant ◽  
Bottom Ash ◽  
Flow Characteristics ◽  
Electricity Production ◽  
Unburned Carbon ◽  
Nox Emissions ◽  
Wood Pellet ◽  
Operating Variables ◽  
Carbon Release ◽  
Air Staging

For renewable electricity production, biomass can fully displace coal in an existing power plant with some equipment modifications. Recently, a 125 MWe power plant burning mainly anthracite in Korea was retrofitted for dedicated wood pellet combustion with a change of boiler configuration from arch firing to wall firing. However, this boiler suffers from operational problems caused by high unburned carbon (UBC) contents in the bottom ash. This study comprises an investigation of some methods to reduce the UBC release while achieving lower NOx emissions. The computational fluid dynamics approach was established and validated for typical operating data. Subsequently, it was applied to elucidate the particle combustion and flow characteristics leading to the high UBC content and to evaluate the operating variables for improving the boiler performance. It was found that the high UBC content in the bottom ash was a combined effect of the poor fuel grindability and low gas velocity in the wide burner zone originating from the arch-firing boiler. This prevented the operation with deeper air staging for lower NOx emissions. Reducing the particle size to <1.5 mm by modifying mills or pretreating the fuel using torrefaction was the only effective way of lowering the UBC and NOx emissions with deeper air staging while increasing the boiler efficiency.

scholarly journals Leachability of Self-Compacting Concrete (SCC) Incorporated with Fly Ash and Bottom Ash by Using Toxicity Characteristic Leaching Procedure (TCLP)

2015 ◽  
Vol 773-774 ◽  
pp. 1271-1275 ◽  
Author(s):  
Aeslina Abdul Kadir ◽  
Mohd Ikhmal Haqeem Hassan ◽  
Eric Cheah Keng Yang
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Power Plant ◽  
Bottom Ash ◽  
Coal Ash ◽  
Absorption Spectrometry ◽  
Toxicity Characteristic Leaching Procedure ◽  
Self Compacting Concrete ◽  
Concrete Technology ◽  
Leaching Procedure

The process of combustion in coal fired power plant generates ashes, namely fly ash (FA) and bottom ash (BA). In addition, coal ash generated from coal combustion generally contains heavy metals within their compositions. These metals are toxic to the environment as well as to the human health. Fortunately, treatment methods are available for these ashes and the use of FA and BA in concrete mix is one of the few. As such, this study presents the work in determining the leachability of self-compacting concrete (SCC) incorporated with FA and BA. The ashes were obtained from Kapar Energy Ventures power plant in Kapar, Selangor. SCC mixtures incorporated with 10%, 20% and 30% FA (replacing cement) and BA (replacing sand) respectively was formulated and casted. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure (TCLP) and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry (AAS). From the results, it was found that incorporation up to 30% of the ashes were safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic (As). On the other hand, incorporation of 20% FA and BA each in SCC provided the most economically viable product, with high strength and low leachate concentrations. In conclusion, this study will serve as a reference which suggests that FA and BA are widely applicable in concrete technology and its incorporation in SCC constitutes a potential means of adding value with appropriate mix and design.

scholarly journals Comparison of NAA XRF and ICP-OES Methods on Analysis of Heavy Metals in Coals and Combustion Residues

2017 ◽  
Vol 17 (2) ◽  
pp. 228
Author(s):  
Agus Taftazani ◽  
Roto Roto ◽  
Novitasari Restu Ananda ◽  
Sri Murniasih
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Power Plant ◽  
Correlation Coefficient ◽  
Bottom Ash ◽  
Enrichment Ratio ◽  
Icp Oes ◽  
Analysis Methods ◽  
Combustion Residues

Heavy metals in the samples of coals and combustion residues (bottom ash and fly ash) from Pacitan coal-fired power plant (CPP) have been identified by using NAA, XRF, and ICP-OES methods. This research was aimed to understand the analysis results correlation coefficient (R) and determine the enrichment ratio (ER) value of the samples by using three analysis methods. The results showed 10 elements have been simultaneously detected in all samples. The correlation coefficient of analysis results of metals content in coals by using NAA-XRF, XRF-ICP OES and with ICPOES-NAA methods gives R2£1 respectively. The correlation coefficient of analysis results of metals content in bottom ash and fly ash by using the methods of NAA-XRF, XRF-ICPOES, and ICPOES-NAA gained R2»1 respectively. ICP-OES method was most satisfactory in this study. The value of ER for identified metals by using the three methods in the samples of bottom ash and fly ash yielded the value over one, and ER value of fly ash was greater in comparison to the bottom ash.

Determination of Traces Heavy Metals from Solid Residues Formed by Combustion of Lignite in Relation to Degree of Accessibility in Soil and Plants

2017 ◽  
Vol 68 (10) ◽  
pp. 2363-2366
Author(s):  
Delia Nica Badea
Keyword(s):  
Heavy Metals ◽  
Power Plant ◽  
Thermal Power ◽  
Reference Value ◽  
Combustion Products ◽  
Toxic Heavy Metals ◽  
Area Of Influence ◽  
Risk Potential

The paper evaluates the presence and content of traces of heavy metals Hg, Pb, Ni, Cd (total forms) from coal and solid combustion products, the degree of transfer and accessibility in the area of influence of a lignite power plant. The content of toxic heavy metals in residues are characterized by RE Meiji [ 1 (Pb and Hg) and REMeij �1 (Ni and Cd) for the filter ash. Pb and Ni content in the soil exceeds normal values, and Pb exceeds and alert value for sensitive soils around the residue deposit (70.20 mg.Kg-1). The degree of accessibility of the metals in plants (TF), reported at the Khan reference value (0.5), indicates a significant bioaccumulation level for the metals: Cd (1.9) and Hg (0.6) inside the deposit; Cd (0.39) at the base of the deposit, Hg (0.8) in the area of the thermal power plant. The trace levels of heavy metals analyzed by GFAAS and CVAAS (Hg), indicates a moderate risk potential for food safety and quality of life in the studied area.

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

Precipitation of heavy metals from coal ash leachate using biogenic hydrogen sulfide generated from FGD gypsum

2013 ◽  
Vol 67 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Madawala Liyanage Duminda Jayaranjan ◽  
Ajit P. Annachhatre
Keyword(s):  
Heavy Metals ◽  
Hydrogen Sulfide ◽  
Sulfate Reduction ◽  
Bottom Ash ◽  
Coal Ash ◽  
Reduction Process ◽  
Fgd Gypsum ◽  
Sulfate Reducing ◽  
Sulfate Reduction Process ◽  
Biological Sulfate Reduction

Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H2S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation.

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