Effect of water-extraction on characteristics of melting and solidification of fly ash from municipal solid waste incinerator

Jiang, Yonghai; Xi, Beidou; Li, Xiujin; Zhang, Ling; Wei, Zimin

doi:10.1016/j.jhazmat.2008.04.033

Cited by 70 publications

(23 citation statements)

References 24 publications

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“…The study of wrapping fly ash by glass bottle has not reported in previous research. Moreover, problem of soluble salts drew attention of system analysis: washing fly ash removed 30% up to 95% of chlorine, and achieved high removal rates of 30.7-72.8% of Ca, Na, K, and Cl at liquid-to-solid rates (L/S) of 10, whereas Pb, Cd and some minor elements were removed by 10-30% [10][11][12][13]. It was mentioned stability and leaching properties of glassy slags would be improved because of more network structures in slag after washing process [5,14].…”

Section: Introductionmentioning

confidence: 99%

Volatilization and leaching behavior of heavy metals in MSW incineration fly ash in a DC arc plasma furnace

Fang

Chen

et al. 2017

Fuel

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Keywords:MSW incineration fly ash Heavy metals Volatilization and leaching behavior DC arc plasma CaO -Al 2 O 3 -SiO 2 (CAS) A B S T R A C T Three fly ash samples collected from different waste incinerators were vitrified using a direct current arc plasma furnace at 1250-1400°C. The influence of water-wash extraction and wrapping pretreatment on the volatilization and leaching behavior of heavy metals was investigated. Results showed: After thermal arc plasma treatment, the volume reduction and weight loss of fly ash were in the range of 68.7-82.2% and 23.8-56.7%, respectively. The residual fractions (wt.%) of heavy metals in slag are in the following sequence: Cr < Ni < Cd < Pb < Cu < Zn. Water-washing could reduce the volatilization rate of heavy metals due to some volatile salts removed by washing, while wrapping of fly ash could most effectively resist heavy metals against volatilizing, especially for Zn and Ni. The possible CaO -Al 2 O 3 -SiO 2 (CAS) ratio for successful melting of fly ash is suggested to be CaO in range of 20-48%, Al 2 O 3 in range of 10-15%, and SiO 2 in range of 40-65%. Moreover, toxicity characteristic leaching procedure results showed that the leaching of heavy metals in slags was much lower than the standard limit of toxicity characteristic leaching procedure (TCLP).

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Section: Introductionmentioning

confidence: 99%

Volatilization and leaching behavior of heavy metals in MSW incineration fly ash in a DC arc plasma furnace

Fang

Chen

et al. 2017

Fuel

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“…Melting can also provide an alternative because it can destroy PCDD/Fs at high temperatures and make various heavy metals inert through their incorporation into the glass matrix. This technique is also limited, however, because most chlorides are too volatile at high temperature over 1000°C to be confined into the vitreous products, which causes secondary pollution (Jiang et al, 2009). Meanwhile, high carbon content in fly ash would accelerate the electrode erosion of plasma or arc melting furnace (Liu et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Meanwhile, high carbon content in fly ash would accelerate the electrode erosion of plasma or arc melting furnace (Liu et al, 2011). Recent reports have found that the water washing pre-treatment for fly ash can reduce undesirable side effect from high chloride in fly ash (Jiang et al, 2009;Zheng et al, 2011;Huang et al, 2011). The appropriate water washing condition is washed twice in distilled water at a liquid-to-solid ratio of 10 or 20 for successful processing (Chiang and Hu, 2010;Liu et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Removal of carbon constituents from hospital solid waste incinerator fly ash by column flotation

2013

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Hospital solid waste incinerator (HSWI) fly ash contains a large number of carbon constituents including powder activated carbon and unburned carbon, which are the major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fly ash. Therefore, the removal of carbon constituents could reduce PCDD/Fs in fly ash greatly. In this study, the effects of the main flotation parameters on the removal of carbon constituents were investigated, and the characteristics of the final product were evaluated. The results showed that loss on ignition (LOI) of fly ash increased from 11.1% to 31.6% during conditioning process. By optimizing the flotation parameters at slurry concentration 0.05 kg/l, kerosene dosage 12 kg/t, frother dosage 3 kg/t and air flow rate 0.06 m(3)/h, 92.7% of the carbon constituents were removed from the raw fly ash. Under these conditions, the froth product has LOI of 56.35% and calorific values of 12.5 MJ/kg, LOI in the tailings was below 5%, and the total toxic equivalent (TEQ) of PCDD/Fs decreased from 5.61 ng-TEQ/g in the raw fly ash to 1.47 ng-TEQ/g in the tailings. The results show that column flotation is a potential technology for simultaneous separation of carbon constituents and PCDD/Fs from HSWI fly ash.

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“…Risk category Original Water washing Acid washing 50th percentile 95th percentile 50th percentile 95th percentile 50th percentile 95th percentile FA1 Cr 8.23 Â 10 À 6 1.13 Â 10 À 5 6.35 Â 10 À 6 8.74 Â 10 À 6 6.30 Â 10 À 6 8.52 Â 10 À 6 Cd 8.56 Â 10 À 9 1.17 Â 10 À 8 8.09 Â 10 À 9 1.11 Â 10 À 8 3.98 Â 10 À 9 5.38 Â 10 À 9 Ni 6.76 Â 10 À 9 9.28 Â 10 À 9 5.31 Â 10 À 9 7.31 Â 10 À 9 4.64 Â 10 À 9 6.27 Â 10 À 9 Total 8.25 Â 10 À 6 1.13 Â 10 À 5 6.36 Â 10 À 6 8.76 Â 10 À 6 6.31 Â 10 À 6 8.53 Â 10 À 6 FA2 Cr 1.33 Â 10 À 5 1.83 Â 10 À 5 1.08 Â 10 À 5 1.49 Â 10 À 5 1.87 Â 10 À 5 2.53 Â 10 À 5 Cd 1.74 Â 10 À 8 2.39 Â 10 À 8 1.87 Â 10 À 8 2.58 Â 10 À 8 9.70 Â 10 À 9 1.31 Â 10 À 8 Ni 1.10 Â 10 À 8 1.51 Â 10 À 8 1.08 Â 10 À 8 1.48 Â 10 À 8 1.40 Â 10 À 8 1.89 Â 10 À 8 Total 1.34 Â 10 À 5 1.84 Â 10 À 5 1.08 Â 10 À 5 1.49 Â 10 À 5 1.87 Â 10 À 5 2.53 Â 10 À 5 FA3 Cr 6.96 Â 10 À 5 9.55 Â 10 À 5 1.24 Â 10 À 4 1.71 Â 10 À 4 1.45 Â 10 À 4 1.96 Â 10 À 4 Cd 2.21 Â 10 À 7 3.03 Â 10 À 7 2.53 Â 10 À 7 3.49 Â 10 À 7 6.17 Â 10 À 8 8.34 Â 10 À 8 Ni 1.27 Â 10 À 8 1.74 Â 10 À 8 1.35 Â 10 À 8 1.86 Â 10 À 8 1.73 Â 10 À 8 2.34 Â 10 À 8 Total 6.98 Â 10 À 5 9.58 Â 10 À 5 1.25 Â 10 À 4 1.71 Â 10 À 4 1.45 Â 10 À 4 1.96 Â 10 À 4 FA4 Cr 7.49 Â 10 À 6 1.03 Â 10 À 5 1.46 Â 10 À 5 2.01 Â 10 À 5 1.21 Â 10 À 5 1.63 Â 10 À 5 Cd 5.40 Â 10 À 8 7.41 Â 10 À 8 7.51 Â 10 À 8 1.03 Â 10 À 7 1.19 Â 10 À 7 1.60 Â 10 À 7 Ni 6.08 Â 10 À 9 8.34 Â 10 À 9 6.97 Â 10 À 9 9.59 Â 10 À 9 9.47 Â 10 À 9 1.28 Â 10 À 8 Total 7.55 Â 10 À 6 1.04 Â 10 À 5 1.47 Â 10 À 5 2.02 Â 10 À 5 1.22 Â 10 À 5 1.65 Â 10 À 5 one among the heavy metals except for K, Ca, and Na in MSWI fly ash samples (Jiang et al, 2009;Wang et al, 2009), which infers that the removal rate of Cr is higher than the soluble chlorides, calcium salts. Besides, due to relatively low concentration of Cd and Ni, no substantial changes have been found in washed fly ash.…”

Section: Samplesunclassified

Can washing-pretreatment eliminate the health risk of municipal solid waste incineration fly ash reuse?

Wang

Zhang

Yang

et al. 2015

Ecotoxicology and Environmental Safety

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Effect of water-extraction on characteristics of melting and solidification of fly ash from municipal solid waste incinerator

Cited by 70 publications

References 24 publications

Volatilization and leaching behavior of heavy metals in MSW incineration fly ash in a DC arc plasma furnace

Volatilization and leaching behavior of heavy metals in MSW incineration fly ash in a DC arc plasma furnace

Removal of carbon constituents from hospital solid waste incinerator fly ash by column flotation

Can washing-pretreatment eliminate the health risk of municipal solid waste incineration fly ash reuse?

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