Bottom Ash Modification via Sintering Process for Its Use as a Potential Heavy Metal Adsorbent: Sorption Kinetics and Mechanism.

Young-Kyu Hong,Sang-Phil Lee,Sung-Chul Kim,Hyuck-Soo Kim,Jae-E Yang,Jin-Wook Kim

doi:10.3390/ma14113060

Young-Kyu Hong, Sang-Phil Lee + Show 4 more

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https://doi.org/10.3390/ma14113060

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Abstract

Heavy metal pollution in the environment is a critical issue, engendering ecosystem deterioration and adverse effects on human health. The main objective of this study was to evaluate heavy metal adsorbents by modifying industrial byproducts. The bottom ash was sintered and evaluated for Cd and Pb sorption. Three adsorbents (bottom ash, sintered bottom ash (SBA), and SBA mixed with microorganisms (SBMA)) were tested to evaluate the sorption kinetics and mechanism using a lab-scale batch experiment. The results showed that the highest sorption efficiency was observed for Cd (98.16%) and Pb (98.41%) with 10% SBA. The pseudo-second-order kinetic model (R2 > 0.99) represented the sorption kinetics better than the pseudo-first-order kinetic model for the SBA and SBMA, indicating that chemical precipitation could be the dominant sorption mechanism. This result is supported by X-ray photoelectron spectroscopy analysis, demonstrating that -OH, -CO3, -O, and -S complexation was formed at the surface of the sintered materials as Cd(OH)2 and CdCO3 for Cd and PbO, and PbS for Pb. Overall, SBA could be utilized for heavy metal sorption. Further research is necessary to enhance the sorption capacity and longevity of modified industrial byproducts.

Highlights

Agricultural fields that are highly polluted with heavy metals may increase their bioavailable fractions in soil, which is transferred to food crops [7,8,9]
The bottom ash (BA) was collected after power generation, and the sintered BA (SBA) was manufactured by mixing BA, low-quality unburned carbon (UNC), and dredged sand (DS)
The viavia thethe sintering process waswas evaluated for heavy metal metal sorpsorption

Summary

Introduction

Heavy metal pollution in soil is a concern because of its adverse effects on ecosystems and human health [1,2,3]. Cd and Pb are considered major soil pollutants, owing to their severe toxicity and because they result in the deterioration of food crops [4,5,6]. Agricultural fields that are highly polluted with heavy metals may increase their bioavailable fractions in soil, which is transferred to food crops [7,8,9]. Spoil, tailing, waste rocks, and mine drainage are the main sources of abandoned metal mines and can cause heavy metal pollution in adjacent environments [13,14,15,16]

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