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

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.

2021 ◽  
Vol 13 (2) ◽  
pp. 535
Author(s):  
Jing Gao ◽  
Tao Wang ◽  
Jie Zhao ◽  
Xiaoying Hu ◽  
Changqing Dong

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.


2012 ◽  
Vol 531 ◽  
pp. 292-295
Author(s):  
Hai Ying Zhang ◽  
Guo Liang Yuan ◽  
Guo Xian Ma

The characteristics and leaching behavior of heavy metals in fly ash, sampled from one MSWI (municipal solid waste incineration) plant in Shanghai China, were investigated. The results indicated that the main elements of fly ash were Fe, K, Na, Cl, Si, Ca, Al, and the total fraction of heavy metals was in the range of 0.8 % - 2.0%. Hence, MSWI fly ash was considered to be one kind of hazardous waste due to its potential environmental risk. Leaching toxicity was performed on fly ash samples from the MSWI plant in Shanghai China. Leaching toxicity of the heavy metals by the ALT (available leaching toxicity) procedure exceeded that by the HVEP (horizontal vibration extraction procedure) standard. Leaching concentrations of Ni, Zn, Cd and Pb exceeded the limit of hazardous waste identification standard. Hence, fly ash is a hazardous waste.


Chemosphere ◽  
2018 ◽  
Vol 195 ◽  
pp. 40-47 ◽  
Author(s):  
Huanan Wu ◽  
Yu Zhu ◽  
Songwei Bian ◽  
Jae Hac Ko ◽  
Sam Fong Yau Li ◽  
...  

Fuel ◽  
2021 ◽  
Vol 283 ◽  
pp. 119278
Author(s):  
Jing Gao ◽  
Changqing Dong ◽  
Ying Zhao ◽  
Tong Xing ◽  
Xiaoying Hu ◽  
...  

2012 ◽  
Vol 249-250 ◽  
pp. 922-926 ◽  
Author(s):  
Hai Ying Zhang ◽  
Guo Xian Ma

Municipal solid waste incineration (MSWI) fly ash, a must by-product in incineration of municipal solid waste (MSW) combustion is of environmental concern due to its enrichment in heavy metals (Ni, Cd, Cu and Pb). Extraction using sulfuric acid is a conventional method of safe treatment of fly ash. In this work, influence of sulfuric acid concentration and liquid to solid ratio on removal efficiency of the four heavy metals was investigated. It was found that Removal ratio followed the decreasing sequence of Cd > Cu > Pb >Zn for acid extraction using sulfuric acid, quite different with that sequence of Pb > Cd > Cu > Zn for extraction using nitric acid. Sulfuric acid was efficient in removing Cd and Cu, but less efficient in removing Ni and Zn. Compared with nitric acid, sulfuric acid was less effective in removing Pb, Cu and Ni.


2012 ◽  
Vol 217-219 ◽  
pp. 869-878
Author(s):  
Xiao Bo Wang ◽  
Zeng Li Zhao ◽  
Chang Feng Yan ◽  
Hai Bin Li ◽  
Yong Chen

Weight loss and heat flow during heating process of municipal solid waste incineration (MSWI) fly ash were investigated through the DSC-DTG experiment carried out from 40°C°C to 1400°C°C, with different heating rates (5°C/min, 10°C°C/min, 20°C°C/min) and different atmosphere (N2, Air). Two main weight loss peaks were found at 800°C°C-1000°C°C and 1000°C°C-1200°C0°C for three different samples. Weight loss ingredients were analyzed by comparing the difference of components between fly ash and slag. Then Kinetics parameters of fly ash melting were acquired by Numerical Solution using a C++ program.Introduction


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