Early solidification/stabilization mechanism of heavy metals (Pb, Cr and Zn) in Shell coal gasification fly ash based geopolymer

Conditioning of sludges improves dewatering characteristics and reduces the quantity of sludge to be handled. Anaerobic digested sludge collected from a sewage treatment plant contained 1.8% to 8% oil. The increase of specific resistance and capillary suction time (CST) with increasing oil content observed in these samples indicates the interference of oil in dewatering. It has been found that addition of municipal solid wastes incinerator fly ash decreases the specific resistances and capillary suction times of oily sludges rapidly up to 3% dosage. Beyond 3% fly ash, the decrease is less significant and the solids content in the sludge cake increases. This optimum dosage remains the same for sludges with varying oil contents from 1.8% to 12%. The total suspended solids of filtrate decreases with fly ash dosage but the toxic concentrations of heavy metals increases considerably. However at the optimum dosage of 3%, concentrations of heavy metals are within the limits for discharging into the sewers. The correlations of CST with the dewatering characteristics such as specific resistance, filter yield and corrected filter yield are established. These correlations can be used to obtain a quick prediction on dewaterability.

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Study on Pore and Chemical Structure Characteristics of Atmospheric Circulating Fluidized Bed Coal Gasification Fly Ash

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.127395 ◽

2021 ◽

pp. 127395

Author(s):

Jiawei Li ◽

Zhichao Chen ◽

Liankai Li ◽

Yanyu Qiao ◽

Zhenhua Yuan ◽

...

Keyword(s):

Fly Ash ◽

Fluidized Bed ◽

Chemical Structure ◽

Coal Gasification ◽

Circulating Fluidized Bed ◽

Structure Characteristics

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An Experimental Study on the Melting Solidification of Municipal Solid Waste Incineration Fly Ash

Sustainability ◽

10.3390/su13020535 ◽

2021 ◽

Vol 13 (2) ◽

pp. 535

Author(s):

Jing Gao ◽

Tao Wang ◽

Jie Zhao ◽

Xiaoying Hu ◽

Changqing Dong

Keyword(s):

Heavy Metals ◽

High Temperature ◽

Fly Ash ◽

Municipal Solid Waste ◽

Solid Waste ◽

Liquid Slag ◽

Melting Process ◽

Waste Incineration ◽

Municipal Solid Waste Incineration ◽

Mswi Fly Ash

Melting solidification experiments of municipal solid waste incineration (MSWI) fly ash were carried out in a high-temperature tube furnace device. An ash fusion temperature (AFT) test, atomic absorption spectroscopy (AAS), scanning electron microscope (SEM), and X-ray diffraction (XRD) were applied in order to gain insight into the ash fusibility, the transformation during the melting process, and the leaching behavior of heavy metals in slag. The results showed that oxide minerals transformed into gehlenite as temperature increased. When the temperature increased to 1300 °C, 89 °C higher than the flow temperature (FT), all of the crystals transformed into molten slag. When the heating temperatures were higher than the FT, the volatilization of the Pb, Cd, Zn, and Cu decreased, which may have been influenced by the formation of liquid slag. In addition, the formation of liquid slag at a high temperature also improved the stability of heavy metals in heated slag.

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Accumulation of heavy metals in stormwater biofiltration systems augmented with zeolite and fly ash

Journal of Environmental Management ◽

10.1016/j.jenvman.2021.113298 ◽

2021 ◽

Vol 297 ◽

pp. 113298

Author(s):

Andreas Aditya Hermawan ◽

Kok Leong Teh ◽

Amin Talei ◽

Lloyd H.C. Chua

Keyword(s):

Heavy Metals ◽

Fly Ash

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Heavy metals stabilization in medical waste incinerator fly ash using alkaline assisted supercritical water technology

Waste Management & Research ◽

10.1177/0734242x10362243 ◽

2010 ◽

Vol 28 (12) ◽

pp. 1133-1142 ◽

Cited By ~ 15

Author(s):

Jian Jin ◽

Xiaodong Li ◽

Yong Chi ◽

Jianhua Yan

Keyword(s):

Heavy Metals ◽

Fly Ash ◽

Supercritical Water ◽

Medical Waste ◽

Waste Incinerator

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Manufacture of Non-Toxic Lava from Recovery of the Incineration Ash by Plasma Fusing Technology

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.2365 ◽

2011 ◽

Vol 194-196 ◽

pp. 2365-2375

Author(s):

Jai Houng Leu ◽

Li Fong Wu ◽

Ay Su

Keyword(s):

Heavy Metals ◽

Fly Ash ◽

Dissolution Rate ◽

Bottom Ash ◽

Reduction Ratio ◽

National Standards ◽

Toxic Heavy Metals ◽

Mixture Ratio ◽

Sustainable Operation ◽

The Stability

This research investigated and explored the overall technical and legal suggestions on mixed ash (bottom ash + fly ash) from the first BOT(built-operation then transfer) incineration plant in south Taoyuan of Taiwan, with the hope of serving as the reference for treating ash from urban refuse incinerator and making sustainable operation management policies in Taiwan. Both bottom ash and fly ash contain high-content harmful metals like lead, chrome, and cadmium, with the lead content exceeding standard value. Plasma fusing technology may effectively settle toxic heavy metals and reduce their dissolution rate. The results show that the increase in percentage of bottom ash could maintain post-fusing strength and produce solidification effect, but this reduced the stability of toxic heavy metals and raised their dissolution rate. Suitable mixture ratio of bottom ash and fly ash was 2:1, volume reduction ratio 0.349, and weight reduction ratio 0.4936. The mixture was fulvous and dense with gloss and adequate strength. The dissolution test of lava products complied with national standards, and they might be used for recycling aggregates and solidifying cement.

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