APPLIED SURFACE SCIENCE
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2023
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IF 6.7
Xiangyuan Deng,Yun Liao,Meng Wang,Detao Xiao
Radon (Rn) is an important contributing factor to lung cancer. Activated carbon (AC) is currently the only Rn adsorbent for industrial applications. However, the effect of the key pore size of AC on Rn adsorption remains unclear, and enhancement of the Rn adsorption performance when using AC is still a challenge. In this work, grand canonical Monte Carlo (GCMC) simulations were performed to simulate the Rn adsorption ability of AC with different pore sizes. The adsorption selectivity of AC with pore sizes from 0.42 nm to 0.60 nm for Rn in the atmospheric environment was much greater than that for nitrogen and oxygen. The Rn adsorption performance was also investigated using KOH-modified activated carbon (KAC) with different pore sizes experimentally prepared using high-temperature roasting. The results showed that when the pore volume of KAC was significantly increased to approximately 0.55 nm, the Rn adsorption performance was obviously improved. Its adsorption coefficient reached 6.50 ± 0.11 m 3 kg −1 , which was 46.7 % higher than that of AC. After heating and regeneration in air, the Rn adsorption performance of KAC was basically unchanged. Combined with the comparative analysis using theoretical and experimental results, the relationship between the Rn adsorption performance of KAC and the pore volume at 0.55 nm is determined, and the accuracy of the GCMC calculation results was substantiated. This research provides a theoretical basis and an experimental method for improving the Rn adsorption performance of AC.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
RSC Advances
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2023
·Vol. 13
·期 43
·30176-30189
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IF 3.9
Wei Yang,Lei Zhang,Meng Li,Ting Zhang,Yue Liu,Juan Liu
In this work, bamboo charcoal (BC) is prepared by pyrolysis of bamboo. Then, KOH modification and surface deposition of Goethite (α-FeOOH) are performed to obtain a new KOH-modified BC loaded with α-FeOOH (FKBC) adsorbent for copper (Cu2+) and fluoride (F−) ion adsorption from aqueous solution. Surface morphology and physiochemical properties of the prepared adsorbent are characterized by scanning electron microscopy-energy dispersive spectrometer, X-ray diffraction, and N2 adsorption–desorption. The effect of pH, contact time, adsorbent dosage, and initial concentration on Cu2+ and F− adsorption is also investigated. In addition, adsorption kinetics and isotherms are fitted to pseudo-second-order kinetics and Langmuir model, respectively. Thermodynamic parameters suggest that the adsorption process is spontaneous and endothermic. The adsorption mechanism is further characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The Cu2+ absorption mainly occurs through ion exchange, coordination reactions, and surface precipitation, while the F− adsorption mainly occurs via ion exchange and hydrogen bonding. The selective adsorption experiments reveal that FKBC has good selectivity for Cu2+ and F−. The adsorption–desorption experimental results indicate that FKBC can be reused for Cu2+ and F− adsorption after regeneration. Results indicate that FKBC can be a promising adsorbent for Cu2+ and F− removal from aqueous solutions.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 11
·3994
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IF 3.4
Qingxiang Wang,Yan Yue,Wenfei Liu,Qing Liu,Yu Song,Chengjun Ge,Hongfang Ma
Biochar can be used to address the excessive use of tetracycline and micronutrient chromium (Cr) in wastewater that potentially threatens human health. However, there is little information about how the biochar, made from different tropical biomass, facilitates tetracycline and hexavalent chromium (Cr(VI)) removal from aqueous solution. In this study, biochar was prepared from cassava stalk, rubber wood and sugarcane bagasse, then further modified with KOH to remove tetracycline and Cr(VI). Results showed that pore characteristics and redox capacity of biochar were improved after modification. KOH-modified rubber wood biochar had the highest removal of tetracycline and Cr(VI), 1.85 times and 6 times higher than unmodified biochar. Tetracycline and Cr(VI) can be removed by electrostatic adsorption, reduction reaction, π–π stacking interaction, hydrogen bonding, pore filling effect and surface complexation. These observations will improve the understanding of the simultaneous removal of tetracycline and anionic heavy metals from wastewater.
研究领域:
环境科学
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污染控制
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材料科学
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产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2021
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IF 6.291
Jing Xiang,Ying Mi,Benxiang Luo,Shuangjiao Gong,Yingru Zhou,Taowu Ma
Modified composite biochar offers a cost-effective solution for the remediation of contaminated sediments; however, few studies have evaluated the effects of modified composite biochar amendment on the ecotoxicity of contaminated sediment based on benthic macroinvertebrates. A 21-day sediment toxicity test was conducted using the freshwater snail Bellamya aeruginosa to examine the intrinsic ecotoxicity of a novel KOH-modified composite biochar (KOH-CBC) and its efficacy for reducing the bioavailability, uptake, and ecotoxicity of perfluorooctanoic acid (PFOA). It was found that KOH-CBC is toxic to B. aeruginosa , which may be attributed to its high polycyclic aromatic hydrocarbons (PAHs) content and alkalinity. The addition of KOH-CBC to PFOA-contaminated sediments can markedly reduce the bioavailability and uptake of PFOA by more than 90% and 50%, respectively, and subsequently alleviate the toxicity of PFOA to B. aeruginosa by at least 30%. Increasing the KOH-CBC dosage is not beneficial for further mitigating the toxicity of PFOA-contaminated sediments. Our findings imply that KOH-CBC is a promising sorbent for the in-situ remediation of PFOA-contaminated sediments. Application of acidified KOH-CBC at a dosage of approximately 1–3% will be sufficient to control the ecotoxicity of PFOA; however, its long-term environmental effects should be further validated.
研究领域:
环境科学
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生态毒理学
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污染控制
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产品关联
DOI
PubMed
高影响因子
WASTE MANAGEMENT
·
2021
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IF 7.145
Huayi Chen,Xingjian Yang,Yonglin Liu,Xueming Lin,Jinjin Wang,Zhen Zhang,Na Li,Yongtao Li,Yulong Zhang
Waste chicken feathers are the ideal precursor for the production of low-cost N-enriched biochar. KOH-modified N-enriched biochar (KNB) containing 15.92 wt% N was successfully prepared using waste chicken feathers. The adsorption kinetics results showed that KNB had rapid Cd (2 h) and Pb (1 h) adsorption rates. The Cd and Pb adsorption capacities of KNB (the values of K F were 22.324 (Cd) and 119.654 (Pb) mg 1−(1/n) ·L 1/n ·g −1 ) were 7.07 and 26.52 times higher than those of the original biochar based on the adsorption isotherm results. The KNB was stable at pH 3–6 and had stronger co-adsorption capacities in double-ion systems. Based on the adsorption experiments and various characterization methods, we concluded that the primary Cd and Pb adsorption mechanisms of KNB involved electrostatic interactions, cation-π interactions, complexation, and K + exchange. The precipitation mechanism could partially account for Pb adsorption but not for Cd adsorption. KOH modification enhanced the electronegativity of biochar and then increased the electrostatic attraction. Surface O- and N-containing functional groups were involved in Cd and Pb adsorption. Graphitic-N, oxidised-N, and O C O were the main active adsorption groups, the relative contents of which increased after KOH modification, thus increasing the Cd and Pb adsorption performance. Therefore, KNB can be used as a fast and highly efficient adsorption agent to remove Cd and Pb from wastewater containing either Cd and Pb or a combination of these two metals.
研究领域:
环境科学
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材料科学
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废水处理
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产品关联
DOI
PubMed
高影响因子
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