Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups

Shin, Jaegwan; Kwak, Jinwoo; Lee, Yong-Gu; Kim, Sangwon; Son, Changgil; Lee, Sang-Ho; Park, Yongeun; Ren, Xianghao; Chon, Kangmin

doi:10.1016/j.envres.2021.111346

Cited by 33 publications

(6 citation statements)

References 61 publications

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“…Table 3 shows that ∆H value for the thermal adsorption process of Ag + in lignin is greater than 0, which suggests that the adsorption process is a endothermic reaction. Meanwhile, ∆H value of Ag + in carboxymethylated lignin is greater than 20 kJ/mol, which indicates that the adsorption process is mainly a chemical adsorption [22]. This result is consistent with the above data of kinetic and thermodynamic experiments.…”

Section: Adsorption Thermodynamics Of Ag + On Carboxymethylated Ligninsupporting

confidence: 89%

Silver Ions Drive Ordered Self-Assembly Mechanisms and Inherent Properties of Lignin Nanoflowers

Chen,

Liu,

Yuan

et al. 2023

Polymers

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Designing anisotropic lignin-based particles and promoting the high-value utilization of lignin have nowadays drawn much attention from scientists. However, systematic studies addressing the self-assembly mechanisms of anisotropic lignin-based particles are scarce. In this work, an interaction including the electrostatic forces and chelating forces between lignin and Ag+ was regulated via carboxymethylation modification. Subsequently, the aggregation morphology of carboxymethylated lignin in a Ag+ solution was observed via SEM. The result showed that a large number of Ag+ intercalated into the lignin molecules when the grafting degree of the carboxyl groups increased from 0.17 mmol/g to 0.53 mmol/g, which caused the lignin molecules to gradually transform from disordered blocks to ordered layers. Dynamics research indicated that the adsorption process of Ag+ in carboxymethylated lignin conforms to the Pseudo-first-order kinetic model. The saturated adsorption amount of Ag+ in the carboxymethylated lignin reached 1981.7 mg/g when the grafting rate of carboxyl groups increased to 0.53 mmol/g, which then fully intercalated into lignin molecules and formed a layered structure. The thermodynamic parameters showed that the thermal adsorption process conforms to the Langmuir model, which indicates that Ag+ is monolayer-adsorbed and intercalated into lignin molecules. Meanwhile, the ΔH values are more than 0, which suggests that this adsorption process is a endothermic reaction and that a higher temperature is conducive to an adsorption reaction. Therefore, self-assembly of lignin in a Ag+ solution under 70 °C is more conducive to the formation of a nanoflower structure, which is consistent with our experimental result. Finally, pH-responsive Pickering emulsions were successfully prepared using a lignin-based nanoflowers, which demonstrated their potential as a catalytic platform in the interface catalysis field. This work offers a deeper understanding into the formation mechanism of anisotropic lignin-based nanoflowers and hopes to be helpful for designing and preparing anisotropic lignin-based particles.

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Section: Adsorption Thermodynamics Of Ag + On Carboxymethylated Ligninsupporting

confidence: 89%

Silver Ions Drive Ordered Self-Assembly Mechanisms and Inherent Properties of Lignin Nanoflowers

Chen,

Liu,

Yuan

et al. 2023

Polymers

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“…The chemical composition of the OPC is summarized in Table 1. Stable nuclides of Co, Cs, and Sr were used as surrogates of their radionuclides, which are mainly contained in the solidified decommissioning wastes from nuclear power plants [41,42]. Stable Eu was also used as a surrogate for its radionuclide because radioactive Eu is commonly leached from solidified bioshield cement [43,44].…”

Section: Cement and Nuclidesmentioning

confidence: 99%

Leaching Behavior of Cesium, Strontium, Cobalt, and Europium from Immobilized Cement Matrix

Goo

Kim

Kang³

et al. 2021

Applied Sciences

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Numerous low-level and intermediate-level radioactive wastes are generated from the decommissioning processes of nuclear power plants; these wastes are immobilized to prevent the release of radionuclides under disposal conditions. In this study, we investigated the leaching behavior of Cs, Sr, Co, and Eu, which are common in immobilized decommissioning wastes. Ordinary Portland cement (OPC) was used as an immobilization agent. During the test, leaching of the nuclides occurred in the order of Cs, Sr, Co, and Eu and decreased over time. The results showed that 41.4% of the total Cs leached over 90 days, although the other elements leached in quantities less than 1.5%. CaCO3 was precipitated by the release of cementitious materials, indicating carbonation of the leachate. The leachability indexes in all cases exceeded the acceptable criteria (>6). The results of the present study suggest that OPC can be effectively used as a binding material to immobilize nuclides (Cs, Sr, Co, and Eu) contained in decommissioning wastes.

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“…The Fukushima Daiichi Nuclear Disaster is widely known for releasing a variety of radionuclides including Cs-137/134, Sr-90, and H-3 into the atmosphere and oceans ( Kirishima et al, 2014 ; Hori et al, 2018 ; Kato et al, 2019 ), which dramatically contaminated the ecosystem and posed a significant threat to human life. One of the most important radionuclides, Sr-90, has excellent water solubility and is easily deposited in bones after ingestion causing bone cancer, anemia, leukemia, and other diseases ( Shin et al, 2021a ). It is also regarded as one of the most serious radioactive contaminants on nuclear power plant sites and the damage of organisms in surrounding forests and oceans ( Kirishima et al, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Strontium Ion Removal From Artificial Seawater Using a Combination of Adsorption With Biochar and Precipitation by Blowing CO2 Nanobubble With Neutralization

Guo

Nhung

Dai

et al. 2022

Front. Bioeng. Biotechnol.

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While enjoying the convenience of nuclear energy development, the environmental contamination by radionuclide leakage is of significant concern. Because of its cost-effectiveness and environmental friendliness, biochar has attracted a lot of attention in the field of radioactive water treatment. Herein, a novel teak peel modified biochar (labeled as PMBN3) was prepared and applied to remove strontium from artificial seawater. The characterisation of the prepared PMBN3 showed it contains numerous oxygen-containing functional groups (i.e. carboxyl and hydroxyl groups), laminar morphology, mesoporous structure, large specific surface area. PMBN3 exhibited great advantages in Sr(II) adsorption, such as rapid adsorption kinetics (<1 h for equilibrium) and superior reusability. The adsorption of strontium by biochar is consistent with pseudo-second order and internal diffusion kinetic models. Among the four types of adsorption isotherms, the Freundlich isotherm showed the best fit with R2 > 0.98. The calculated thermodynamic parameters indicate that strontium adsorption on biochar occurs exothermically and spontaneously. Furthermore, for efficient removal of Sr(II), CO2 nanobubbles were blown into artificial seawater to precipitate the interfering metal ions, and followed by the adsorption of PMBN3 towards residual metal ions with the removal rate of Sr(II) over 99.7%. Finally, mechanistic studies have shown that the strontium adsorption process by PMBN3 is a multiple adsorption mechanism consisting of ion exchange between H+ (from -OH and -COOH) and Sr(II), and weak intermolecular forces between Sr(II) and the PMBN3 adsorbent. This study creatively combines chemisorption and nanobubble precipitation for strontium removal, which provides great reference value and guidance for environmental remediation.

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Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups

Cited by 33 publications

References 61 publications

Silver Ions Drive Ordered Self-Assembly Mechanisms and Inherent Properties of Lignin Nanoflowers

Silver Ions Drive Ordered Self-Assembly Mechanisms and Inherent Properties of Lignin Nanoflowers

Leaching Behavior of Cesium, Strontium, Cobalt, and Europium from Immobilized Cement Matrix

Strontium Ion Removal From Artificial Seawater Using a Combination of Adsorption With Biochar and Precipitation by Blowing CO2 Nanobubble With Neutralization

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