scholarly journals Fresh Bottom Ash Characteristics Dependence on Fractional Composition

2017 ◽  
Vol 9 (4) ◽  
pp. 363-370
Author(s):  
Jurgita Seniūnaitė ◽  
Saulius Vasarevičius

Waste incineration process generates two main by-products streams: fly ash and bottom ash. Bottom ash is composed of a variety of oxides, heavy metals and salts. Chemical materials distributed unevenly in different fractions of bottom ash. This study investigates the heavy metals (Pb, Cd) content dependence of bottom ash and fraction composition. Studies were performed with five different fractions (0–2 mm; 2–5.6 mm; 5.6–11.2 mm; 11.2–22,4 mm; 22.4–40 mm) of fresh bottom ash. After a one-step leaching test (distilled water was used as a solvent), was determinate, that highest concentrations of the lead (Pb) (from 0.141 to 0.146 mg/l) are leached from the smallest (0–2 mm 2–5.6 mm) bottom ash fractions particles. Heavy metals concentration in these fractions eluates respectively was 2.83 and 2.91 times higher than the limit value of leaching. The highest concentration of cadmium (4.214 mg/l) was determinate in 0–2 mm fraction bottom ash eluate. concentration of cadmium was 1.40 times higher than the limit value of leaching. It can be concluded that 0–2 mm; 2–5.6 mm fraction bottom ash can’t be used in civil engineering, without pre-treatment (eg. washing or aging).

2021 ◽  
Vol 121 ◽  
pp. 33-41
Author(s):  
Yanjun Hu ◽  
Lingqin Zhao ◽  
Yonghao Zhu ◽  
Bennong Zhang ◽  
Guixiang Hu ◽  
...  

2011 ◽  
Vol 474-476 ◽  
pp. 1099-1102
Author(s):  
Hai Ying Zhang ◽  
Yi Zheng ◽  
Hong Tao Hu ◽  
Jing Yu Qi

Bottom ash from municipal solid waste incineration (MSWI) has been previously suggested as an adsorbent for removing heavy metals from wastewater due to its high porosity and large surface area. In this study the adsorption characteristics of heavy metals were investigated using various particle sizes of MSWI bottom ash. The adsorption experiment was conducted using synthetic wastewater containing Cu, Zn, Pb and Cd as a function of residence time, initial pH, ash dosage and particle size, respectively. The adsorption rate increased with decreasing particle size and with increasing residence time. Through the above analysis, this work proved that bottom ash was effective in adsorbing the four heavy metals.


2018 ◽  
Vol 36 (7) ◽  
pp. 635-644 ◽  
Author(s):  
Yahaya Yakubu ◽  
Jun Zhou ◽  
Zhu Shu ◽  
Yigen Tan ◽  
Zhengliang Zhao ◽  
...  

This study sought to establish the effectiveness of water washing pre-treatment on the quality of municipal solid waste incineration (MSWI) fly ash (FA) for reuse and solidification or stabilization (S/S). Initial analysis of the FA sample shows that it did not meet the USEPA-1311 toxicity characteristic leaching procedure (TCLP) regulatory limits of 2011. As a result, a two-stage water washing process was carried out an attempt to improve the quality of the MSWI FA. After the washing pre-treatment, the heavy metals in the FA sample met the regulatory limits, thereby making it non-toxic for reuse or safe disposal. The leachate from the washing process also passed regulatory standards of China (GB 8978 – 1996) and the 2011 USEPA-1311. The washing process successfully removed more than 98% of each heavy metal under study. The process was excellent at removing cadmium (99.99%) and very good at removing the rest of the heavy metals. The 28-day compressive strength increased as the quantity of FA decreased. Also, all the heavy metals in the samples prepared with the pre-treated FA met the USEPA-1311 TCLP regulatory limit for reuse and safe disposal. The heavy metals leachability and compressive strength tests showed that the effect of cement-based S/S was largely influenced by its quantity in the samples. The highest compressive strength was attained by using 55% of the FA as replacement for cement. However, FA replacements of up 70% also yielded good results that met the 1989 USEPA standard of 0.34 MPa (50 psi).


2012 ◽  
Vol 164 ◽  
pp. 289-292 ◽  
Author(s):  
Rui Jing Zhang ◽  
Yan Jun Hu

Abstract: The presented study mainly focused on investigating detailed engineering properties of municipal solid waste incineration residues as road construction materials with different application classes. Also, the leachability of heavy metals and salts in the residues as a function of the ratio of liquid and solid was tested. The Chinese specifications about road construction materials were employed to evaluate the application capacity of the waste incineration residues. The obtained results indicate that bottom ash basically complies with the technical requirements for road base and sub-base materials with exception of the low compataclity and high organic content of the fine fraction. The toxicity test showed that bottom ash can satisfy the limit values of heavy metals and salts that was established by Chinese specification for hazard solid waste. For the application of the ash in road base, it should be mixed with other materials to improve the compataclity. Pretreatment of fine fraction of bottom ash to remove organic matter is necessary.


2020 ◽  
Vol 1010 ◽  
pp. 653-658
Author(s):  
Roshazita Che Amat ◽  
Khairul Nizar Ismail ◽  
Khairel Rafezi Ahmad ◽  
Norlia Mohamad Ibrahim

Municipal solid waste incinerators (MSWI) produce by products which can be classified as bottom and fly ashes. The bottom ash accounts for 85-90 % of solid product resulting from MSW combustion. The objective of this study was to assess the feasibility of application of municipal solid waste incineration (MSWI) bottom ash as a supplementary cementations material for the preparation of blended cement. The used of bottom ash as a research material is caused by substances contained in cement is almost the same with bottom ash. Bottom ash was found to have some reactivity, but without greatly affecting the hydration process of OPC at 10 % replacement with 10% metakaolin is required to be used in the production of concrete in order to improve strength.


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