SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Lei Yao,Chao Hong,Yangxu Qi,Lie Wu
In this study, we developed a novel magnetic composite of walnut shell biochar (WSB) and modified it with ZIF-7 for the purpose of removing Co 2+ ions. We conducted a comprehensive evaluation of its performance in Co 2+ removal, considering various factors such as contact time, temperature, adsorbent dose, pH, and initial Co 2+ concentration. Utilizing response surface methodology-central composite design (RSM-CCD), we examined the interactions between these variables. The specific surface area and magnetic saturation value of the WSB/MnFe 2 O 4 /ZIF-7 composite were determined as 170.560 m 2 .g −1 and 23.469 emu.g −1 , respectively. ANOVA analysis indicated that our model effectively captures the interactions between variables, with a high R 2 value of 0.9982, explaining 99.82 % of the experimental data. Optimal conditions for maximum Co 2+ adsorption efficiency (99.05 %) were identified as follows: a contact time of 44.82 min, pH of 6.04, adsorbent dose of 0.947 mg.L -1 , temperature of 25.55 °C, and Co 2+ concentration of 11.13 mg.g −1 . Kinetic studies revealed that the Pseudo 2nd order kinetic model provided the best fit to the experimental data. The negative entropy parameter indicated a decrease in disorderliness during the adsorption process, while the exothermic nature of adsorption was confirmed by enthalpy values of −92.751 and −40.511 kJ.mol −1 for WSB/MnFe 2 O 4 /ZIF-7 and WSB, respectively. Furthermore, the Langmuir isotherm model demonstrated excellent fitting to the isotherm results, suggesting the dominance of homogeneous surfaces in adsorption. The maximum adsorption capacities for Co 2+ using WSB/MnFe 2 O 4 /ZIF-7 and WSB were determined to be 29.26 and 22.39 mg.g −1 , respectively. The WSB/MnFe 2 O 4 /ZIF-7 magnetic composite demonstrates promising potential for efficiently removing Co 2+ from both natural water sources and industrial wastewater, highlighting its versatility and effectiveness in environmental remediation applications.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Xueqian Wu,Zhen Li,Jiangyan Tao,Yufei Xie,Wei Liu,Songjian Zhao
The Fenton technology used for treating formaldehyde-containing wastewater (HCHO) has limitations in terms of pH, efficiency, and cost. To address these issues, a Fe x -HT Fenton-like catalyst was developed in this study. This catalyst combines active Fe with walnut shell biochar (HT) that contains surface defects, resulting in a highly effective solution for the rapid purification of formaldehyde wastewater in complex environments. The carbon defects on the HT surface play a crucial role in stabilizing the active Fe binding, while the appropriate loading of Fe further enhances the specific surface area of HT. Additionally, the porous structure of HT provides ample contact sites for formaldehyde. Furthermore, the Fe 3 -HT catalyst exhibits superparamagnetism, allowing for convenient recovery of the catalyst after use. Experimental results demonstrate that Fe 3 -HT achieves an impressive 90% degradation rate for systems containing HCHO concentrations ranging from 200 to 800 mg/L. The effects of feed ratio, pH, and formaldehyde concentration on the performance of Fe 3 -HT were thoroughly investigated. Moreover, a possible mechanism for the degradation of HCHO by the Fe 3 -HT Fenton-like catalyst was proposed. The environmentally friendly catalyst developed in this study boasts numerous advantages, including low cost, high treatment capacity for wastewater, and strong adaptability to complex wastewater environments.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Junhao Huang,Zhangtao Li,Shengdao Shan,Malik Tahir Hayat,Jun Meng
The escalation of metal(loid) contamination in global water poses severe risks to ecological environment safety. Meeting the ‘pollution control with waste’ strategy, we utilized eco-friendly waste tea leaf extract and walnut shell to first fabricate a greenly synthesized nanoscale zero-valent iron impregnated walnut shell biochar (G-nZVI/WSB) for the simultaneous sequestration of cadmium (Cd), lead (Pb), and arsenic (As) from aqueous systems. Since the interactions among these metal(loid)s during adsorption on G-nZVI/WSB and their corresponding mechanisms remain unclear, we conducted a series of batch experiments coupled with characterization techniques. The optimal pyrolysis temperature and Fe/C ratio for G-nZVI/WSB were determined to be 650 °C and 20 %, respectively. Under optimal conditions (contact time = 24 h, pH = 6), G-nZVI/WSB exhibited theoretical maximum adsorption capacities for Cd(II), Pb(II), and As(III) of 52.96, 135.1, and 8.414 mg g −1 , respectively, which were significantly higher than those of WSB carrier. In single and combined systems, the monolayer and chemical adsorption of metal(loid)s were predominant, with their competitive affinity for active sites following the order of Pb(II) > Cd(II) > As(III). Characterization analyses using FTIR, SEM, XRD, and XPS confirmed the specific adsorption mechanisms of G-nZVI/WSB for these metal(loid)s, including cation-π interactions, coprecipitation, oxidation, and coordinated complexation. Notably, G-nZVI/WSB exhibited excellent adsorption stability over five cycles of adsorption-desorption, which achieved the efficient purification of multi-contaminated actual wastewaters to meet the standards for wastewater discharge or drinking water. These findings demonstrate the significant potential of G-nZVI/WSB as an eco-friendly and promising nanocomposite for treating metal(loid)-contaminated wastewater.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Heliyon
·
2024
·
IF 3.4
Caixia Sun,Gangjun Wang,Yuhong Liu,Ke Bei,Guoguang Yu,Weiran Zheng,Yuxue Liu
Biochar derived from biomass pyrolysis has proven to be an excellent material for pesticide adsorption and can be used as soil amendment for pesticide non-point pollution. However, the adsorption and desorption mechanisms for certain biochar and pesticide are still unclear. In this study, we investigated the properties of biochar derived from walnut (Juglans regia L.) shell (WSB), and used batch equilibrium method to investigate the adsorption and desorption behavior for chlorantraniliprole (CAP). The physical-chemical analysis showed that there were mainly lignin charcoal of alkyl carbon, methoxyl carbon, aromatic carbon, and carboayl carbon as the primary carbon compounds of WSB. The π - π electron donor acceptor interaction, electrostatic interaction, and hydrogen bond were the primary adsorption mechanisms of the WSB adsorption. Batch equilibrium study under 298 K showed that WSB application in the soil significantly improved the adsorption ability for CAP, and the adsorption behavior was a mono-layer adsorption process as Langmuir model fitted the adsorption isotherm data better than the Freundlich model. While Freundlich model analysis showed that WSB addition to the soil changed the isothermal adsorption line from the S style to the L style. The spontaneous degree reaction of sorbents from strong to weak was in the following order: 5%-WSB >7%-WSB >10%-WSB >1%-WSB >3%-WSB > soil > WSB, and the maximum application effect was achieved at 5 % (m/m) WSB dosage mixed with the soil. Therefore, we considered that WSB addition in soil increased its CAP adsorption capacity, and 5 % (m/m) WSB application was the best choice for CAP pollution control. These data will contribute to the adsorption mechanism and the optimal use dosage of WSB for CAP pollution control.
研究领域:
环境科学
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农业科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
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IF 6.2
Riyi Lin,Ruiqi Liu,Lijuan Wang,Yiya Wang,Ningmin Zhu,Dengyu Chen,Liqiang Zhang
B-doping walnut shell char was prepared by the premodified doping method. The effects of B-doping amount, doping temperature, and coupling activation agent (activator amount, activation temperature) on the physicochemical structure and CO 2 adsorption performance of walnut shell biochar were investigated using BET, SEM, Raman, XRD, FT-IR, and XPS characterization techniques. The results indicated that B-doping walnut shell char exhibited a high specific surface area, and the pore structure was dominated by micropores. As the amount of B-doping increased, the CO 2 adsorption capacity of walnut shell char initially rose and then declined. The optimal doping mass ratio was 2:1, and the best pyrolysis temperature was 800 °C. The biochar pores became more abundant and disorderly after KOH activation. Excessive amounts of activators could damage the pore structure of activated char, thereby reducing the adsorption performance. The optimal mass ratio of the activator to walnut shell char was 1:1. As the activation temperature increased, the adsorption capacity of activated char for CO 2 initially improved and subsequently declined. The optimal activation temperature of walnut shell char was 700 °C. The optimal CO 2 adsorption performance was achieved by the CK1–1–700, which was 76.70 % higher compared to W800 without B-doping. Additionally, CK1–1–700 exhibited good cyclic performance. B-doping and activation treatment significantly enhanced the CO 2 adsorption capacity of walnut shell char. These research findings could serve as a reference for the high-value utilization of biomass.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2024
·Vol. 100
·期 1
·90-103
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IF 2.8
Qingkun Wang,Yanping Zhang,Fen Li,Wenxiao Liu,Liran Ma
BACKGROUND Graphite-like biochar of NWSC600K was prepared at 900 °C using walnut shell as the raw material and aqueous ammonia (NH 3 ·H 2 O) as an activator, and characterized using transmission and scanning eletron microscopy (TEM, SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy and Fourier transform infrared (FTIR). The study investigated the adsorption performance and mechanism of NWSC600K for ciprofloxacin (CIP). RESULTS The results showed that extremely tiny pores were found on the surface of NWSC600K, which increased its specific surface area to 823.91 m 2 g −1 , whereas the average pore size of NWSC600K decreased to 3.23 nm. The results of TEM, XRD and Raman spectroscopy detected well-arranged lattice stripes as well as characteristic peaks corresponding to the graphite lattice appearing on the surface of NWSC600K. Moreover, the I D / I G value for NWSC600K was 1.429. The FTIR results showed that functional groups including the amino group were formed on NWSC600K. CONCLUSION The adsorption capacity of NWSC600K for CIP was 158.14 mg g −1 and the corresponding removal rate was 97.5% at pH 7. The pH value impact on the removal efficiency of CIP greatly, and the removal rate of CIP decreased linearly with increasing pH. The coexisting ions also would inhibit the adsorption of CIP on NWSC600K. Results obtained from kinetic and isotherm models, thermodynamics and characterization analyses suggested that pore-filling, π–π stacking, hydrogen bonding, hydrophobicity and electrostatic interaction existed during the adsorption process. The adsorption was a nonspontaneous exothermic reaction. © 2024 Society of Chemical Industry (SCI).
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Yifu Hu,Tinglin Guo,Fangfang Xia,Zejuan Wang,Wentao Wang,Yi Wang,Shenghua Ma
In this research work, biochar-zirconium phosphate (BC-Zr-P) nanocomposites were utilized for the adsorption of Pb (II) in sewage through functionalization of zirconium and phosphate on the surface of biochar. A series of characterization analyses were conducted on BC-Zr-P nanocomposites to comprehend their morphology and functional groups. Furthermore, the adsorption performance of BC-Zr-P towards Pb (II) in aqueous solution was investigated and four crucial parameters including concentration, pH, adsorption time and temperature were optimized. The experimental results demonstrate that BC-Zr-P exhibits a high adsorption capacity for lead ions with a value of 82.04 mg g −1 . Comparative analysis indicates that BC-Zr-P possesses excellent potential as an effective sorbent for lead removal. The adsorption capacity of the material for Pb (II) is highly pH-dependent, with optimal performance observed at pH 2.5, indicating that ion exchange plays a dominant role in the adsorption process and leading to significant changes in adsorption capacity. Rapid kinetic performance within 2 h suggests chemisorption of Pb (II) by BC-Zr-P. We observed a strong agreement between the pseudo-second-order kinetic model and the experimental data, while the adsorption isotherms at different temperatures were well described by the Langmuir model, which outperformed the Freundlich model. These results provide evidence for a monolayer chemisorption mechanism of BC-Zr-P. In addition, the impact of varying temperatures on the adsorption capacity of BC-Zr-P was examined within the range of 278.15–318.15 K, and the thermodynamic behavior of adsorption was analyzed by determining Δ S o and Δ H o through a linear relationship between lnK d and 1/T. The positive value obtained for Δ H o suggests that the process of adsorption is endothermic. BC-Zr-P had excellent selective adsorption capacity for Pb (II) ions in various metal ion solutions and had practical application value for the adsorption of Pb (II) ions in sewage.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2020
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IF 5.647
Xinxiang Geng,Siying Lv,Jing Yang,Shihai Cui,Zehua Zhao
The novel HNO 3 -modifitied biochar (NBC) was synthesized from walnut shell. The NBC was characterized from scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectrum . The NBC was then used in the adsorption of sulfadiazine, sulfamethazine and sulfachloropyridazine from aqueous solution. The material surface has carbon/oxygen-contained groups, which is benefit for the adsorption. The results showed the adsorption ability of NBC on three sulfonamides were 32, 46, and 40 mg g −1 , respectively. The kinetic was found to follow the Elovich model and the isotherm conformed Freundlich. Adsorption was more favorable at weak acidic solution. The interactions mainly include π - π EDA, electrostatic interaction, Lewis acid-base interaction, hydrophobic interaction and H-bond.
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
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Tao Chen,Guangzhu Cao,Yi Qiang,Yanfeng Lu,Ronggao Qin,Wan Xu,Yiming Xie,Ruoyu Mao
The modified walnut shell biochar (WBC) was prepared through zinc-iron bimetallic oxide modification (ZF@WBC) at 600 °C under oxygen-limited conditions in this study. Through adsorption experiments, characterization analyses, and density functional theory (DFT) calculations, the adsorption properties of ZF@WBC to Pb (II) were investigated and the mechanism underlying such adsorption was elucidated. Characterization results showed that the surface area (375.9709 m 2 /g) and total pore volume (0.205319 cm 3 /g) of ZF@WBC were significantly greater than those of walnut shell biochar. The maximum adsorption capacity of ZF@WBC for Pb (II) was found to be 104.26 mg/g, which is 2.57 times higher than that of WBC according to the adsorption experiments conducted. The observed adsorption behavior followed both the pseudo-second-order (PSO) kinetic model and Langmuir isothermal adsorption model, suggesting that chemisorption plays a major role in the absorption process. Based on SEM, XRD, XPS, FTIR characterizations along with DFT calculations performed in this study, it can be concluded that surface complexation, ion exchange, electrostatic attraction, physical absorption are among the main mechanisms responsible for absorption of Pb (II) by ZF@WBC. Furthermore, even in the presence of interfering ions at different concentrations, ZF@WBC exhibited a removal rate above 70% for Pb (II). Therefore, ZF@WBC has great potential as an effective absorbent for removing Pb (II) from wastewater, while also offering opportunities for biomass waste resource utilization.
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
PubMed
高影响因子
POLYMER BULLETIN
·
2025
·Vol. 83
·期 3
·147
·
IF 4
Wang Ying,Dayo Abdul Qadeer,Li Jie
Growing eco-awareness drives research into natural filler-reinforced composites, but hydrophobicity and incompatibility of fillers with matrices are significant challenges. This study investigates the effects of walnut shell biochar (WSBC) as an additive filler in silane-treated hemp fibre (SHF) composites produced with a bio-based epoxy/benzoxazine copolymer via an isothermal compression molding technique. The WSBC particles having 43.66 μm average particle size were produced in a N 2 atmosphere pyrolysis at 400 °C. Produced composites were tested for mechanical, thermal, and thermomechanical properties. The water absorption was significantly reduced as the loading of WSBC share was enhanced. The optimal mechanical properties were recorded on 12 wt% WSBC particle reinforcement, including tensile strength (87.47 ± 3.98 MPa), Young’s modulus (5.66 ± 0.16 GPa), flexural strength (167.47 ± 4.89 MPa), flexural modulus (6.51 ± 0.24 GPa), and impact strength (18.51 ± 0.54 kJ/m 2 ). The highest storage modulus and the lowest damping factor values were observed for the WSBC15 specimen. Moreover, thermal stability was gradually enhanced, and the highest char yield (53.46 ± 0.15%) was recorded for the WSBC15 specimen. Results confirm that these lightweight and eco-friendly composites are promising for structural applications, sporting goods, and internal parts of automotive and aerospace industries.
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高影响因子
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