ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2021
·Vol. 28
·期 22
·28732-28749
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IF 4.223
Dovi Evans,Kani Alexander Nti,Aryee Aaron Albert,Jie Ma,Li Jianjun,Li Zhaohui,Qu Lingbo,Han Runping
In this research, the eco-friendly cationic surfactant modified walnut shell (WNS-CTAB) was synthesised to enhance the uptake for bisphenol A (BPA) and Congo red (CR) from aqueous solution. The characterisation of WNS-CTAB was performed using Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), etc. to know its physiochemical properties. The adsorption equilibrium results were best described by the Langmuir isotherm model, which confirmed the monolayer adsorption of the pollutant molecules onto the adsorbent’s surface. The maximum monolayer adsorption quantity of WNS-CTAB was established to be 38.5 mg g –1 for BPA and 104.4 mg g –1 for CR at 303 K, respectively. Pseudo-second-order kinetic models described the adsorption kinetics of both BPA and CR. Furthermore, the intra-particle diffusion was applied to analyse the kinetic results and was established that the rate was not solely controlled by diffusion. The mechanisms associated with BPA and CR adsorption onto the WNS-CTAB may include van der Waals interaction, hydrophobic interaction, and electrostatic force. WNS-CTAB demonstrated a good reusability potential with desorption through three successive adsorption-desorption cycles performed in both experiments. Moreover, in the binary system, the adsorption capacity of BPA witnessed a 66% decrease while CR saw marginal reduction of 8.0 %. This suggests that WNS-CTAB had a higher affinity for binding to CR with higher selectivity as compared with BPA. Therefore, WNS-CTAB has exhibited huge potential to serve as a functional material for practical use in the treatment of wastewater. Graphical abstract
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2025
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IF 8.4
Yaxing Bai,Xuefeng Hu,Huixian Du,Meng Gao,Zilong Li,Yuhuan Fei
To expand the utilization of discarded walnut shells and enhance the photocatalytic activity of graphitic carbon nitride(g-C 3 N 4 ), the carbon-rich graphitic carbon nitride anchored with Fe sites (FeW-CN) was synthesized via a walnut shell-based biochar-assisted strategy. Unlike the direct thermal copolymerization of melamine for g-C 3 N 4 , the iron-loaded walnut shell-based biochar (FeW) was first synthesized, followed by thermal copolymerization of melamine with FeW to form FeW-CN. The C substitution on the triazine ring enhanced the light absorption and electron migration for FeW-CN. And the Fe sites interacting with N-(C) 3 further improved the migration and the utilization rate of photogenerated carriers. During the degradation of 2-Mercaptobenzothiazole, FeW-CN showed excellent photocatalytic performance and stability compared with g-C 3 N 4 . Moreover, FeW-CN maintained excellent photocatalytic performance in river water. Combination of electron paramagnetic resonance with active species quenching experiments, the synergistic mechanism of singlet oxygen, holes, and superoxide radicals was confirmed in the FeW-CN system. Compared to g-C 3 N 4 , the Fe sites and C substitution enhanced the production of singlet oxygen.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2025
·
IF 6.7
Yan Cui,Wenrui Du,Yao Zhang,Jifan Hu,Weiwei Kang
Quinoline is a representative refractory ammonia nitrogen contaminant in coking wastewater, which presents a hazard to the environment and humanity. Thus, effective settlement of quinoline is eagerly required. Nevertheless, existing adsorbents are expensive and inefficient in quinoline adsorption. It is significant to explore a low-cost and efficient adsorbent. Herein an environmental-friendly activated biochar derived from agricultural waste walnut shell was synthesized. Activated biochar displays large surface area, rich pores and high surface activity. The adsorption behavior of activated biochar was tested under static and dynamic adsorption systems. Activated biochar represents excellent adsorption performance and industrial application potential. Under the conditions of 298 K, 650 rpm and pH = 7, the activated biochar's saturated adsorption capacity and equilibrium time for quinoline are 342.56 mg g −1 and 20 min, respectively. After five adsorption-desorption cycles, the adsorption capacity retained 93.43 % of the incipient value, indicating that activated biochar exhibits excellent regeneration performance. Moreover, activated biochar could maintain good adsorption performance in real wastewater. More importantly, using walnut shell as the raw material could save costs and realize resource utilization. The negative Δ G θ and positive Δ H θ values demonstrate that the adsorption process is spontaneous and endothermic, which follows the pseudo-first-order kinetics and fits well with the Langmuir–Freundlich model. This work has a good guiding significance in the domain of sewage purification.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
·
IF 7.968
Evans Dovi,Aaron Albert Aryee,Alexander Nti Kani,Farid Mzee Mpatani,Jianjun Li,Lingbo Qu,Runping Han
This research investigated the feasibility of removing hexavalent chromium (Cr(VI) (e.g., HCrO 4 − , CrO 4 2− and Cr 2 O 7 2− ions) from water using walnut shells functionalized with amino groups (ACWNS) in a batch and continuous adsorption mode. The characterization of ACWNS was carried out utilizing FTIR, XPS , SEM, and BET methods. Adsorption was investigated in terms of pH, dose, concentration, and contact duration. Furthermore, at different temperatures, the adsorption isotherms , kinetics, and thermodynamics were studied. The Langmuir model described the experimental batch and column modes, while the Thomas and pseudo-second-order kinetics models predicted continuous and batch adsorption, respectively. The maximum uptake quantity toward Cr(VI) was 236.8 mg g –1 in batch mode and 308.4 mg g –1 in column mode at 303 K. There is some selective adsorption for Cr (VI) with some dyes coexisting in solution. Electrostatic interactions and the reduction process mediated Cr(VI) adsorption by ACWNS. The mass transfer potential (B) and the affinity between ACWNS and Cr(VI) (β) were computed using the modified mass transfer factor model. Since the attraction of Cr (VI) to ACWNS is more robust, the B value increases as the concentration increases. Again, MTZ assessment reveals that as MTZ length rises, diffusion resistance increases, resulting in increased adsorption. The adsorbent demonstrated improved regeneration capacity and therefore showed potential for the uptake of Cr(VI) ions from wastewater. Availability of data and material The dataset produced and processed during this research is available upon reasonable request from the corresponding author.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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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
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
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2025
·
IF 4
Gorar Athar Ali Khan,Zhiyi Guo,Zhicheng Wang,Daham Abbas,wang Xudong,Wang Jun,Liu Wen-Bin
Using agricultural waste as biocarbon material is a recent development with many potential applications. Nutshells can be utilized to produce biocarbon, enhancing the electrical properties of thermoset composites. In this research, Walnut shells (WSs) were carbonized at 750 °C, and activated carbon filler was thoroughly examined. Isothermal compression molding was used, and composites were produced by incorporating 1–2.5 wt.% of carbonized bio-filler (CW) into Vanillin-furfuryl amine-derived bio-benzoxazine. The composites showed improved thermal stability, increasing from 293 to 321 °C; Char yield enhanced from 53.3% to 60.4%. The flexural modulus and flexural strength exhibited enhancements of 41.3% and 20%, respectively, while toughness significantly increased from 0.87 to 0.94 N-mm compared to the neat matrix. Heat deflection temperature tests showed improved thermomechanical properties in composites. Flammability tests indicated that they are flame-resistant and fire-safe due to the CW filler. Thermal conductivity enhanced by 6%, and dielectric characteristics increased by 56.7% with 2.5 wt.% filler reinforcement. With the above findings, these composites can be utilized in designing parts exposed to fire, high temperatures, efficient energy storage, enhanced functionality in electronic devices, and improved insulation efficiency.
研究领域:
材料科学
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可持续发展
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
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2021
·
IF 7.145
Xiefei Zhu,Zejun Luo,Xifeng Zhu
Enriching high-value chemicals from the pyrolysis of agricultural and forestry waste is an efficient way to achieve sustainable development and large-scale application of biomass pyrolysis. Phenols, as important chemical raw materials, spices and food additives, have attracted widespread attention. Herein, a novel technical route of torrefaction pretreatment combined with fractional condensation in pyrolysis loop was proposed to enrich the phenols in liquid products. In this study, the enrichment of phenols from the pyrolysis loop of walnut shell under the combination of torrefaction and fractional condensation was explored using a fixed-bed pyrolysis reactor equipped with a three-stage condensation system. Simultaneously, the effects of torrefaction on feedstocks were investigated through a thermogravimetric analyzer based on the characteristics of feedstocks. The results showed that the torrefaction and pyrolysis loop had a negative impact on the pyrolysis efficiency and the yield of liquid products, while the change in the condensation efficiency depended on the combined effects of torrefaction and pyrolysis loop. In addition, phenols tended to be enriched in the second condensation stage, especially phenol, o-cresol, 4-ethylphenol. Importantly, torrefaction could significantly enrich phenols in the liquid products, and the enrichment of phenols is relatively increased by 109.44% at least. Moreover, the pyrolysis loop was also beneficial to the enrichment of phenols, which was at least 90% higher than that of walnut shell. This study provided a potential route to enrich high value-added products from the pyrolysis loop of lignocellulosic biomass.
研究领域:
生物质能
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化学工程
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可持续发展
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
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2019
·
IF 1.343
Hongjuan Zheng,Zhengqian Sun,Hongjuan Zhang
Poly(lactic acid) (PLA) has good environmental compatibility, however, its high brittleness, slow rate of crystallization, and low heat distortion temperature restrict its widespread use. To overcome these limitations, in this study, PLA was mixed with walnut shell (WS) powders. The effects of WS powders on the morphology and the thermal and mechanical properties of PLA were investigated. The products were characterized by differential scanning calorimetry (DSC), infrared (IR) spectroscopy, polarizing optical microscopy (POM), and various mechanical property testing techniques. The results showed that WS powders had a significant effect on the morphology and the thermal and mechanical properties of PLA. The tensile strength, impact strength, and elongation at break of the PLA/WS composites first increased and then decreased with the increasing addition of WS powders. When the addition of WS powders was about 0.5 wt%, they reached maximum values of 51.2 MPa, 23.3 MPa, and 19.0%, respectively. Compared with neat PLA, the spherulite grain size of the composites could be reduced and many irregular polygons were formed during crystallization. The melting, cold crystallization, and glass-transition temperatures of the composites were lower than those of neat PLA.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Evans Dovi,Aaron Albert Aryee,Alexander Nti Kani,Farid Mzee Mpatani,Jianjun Li,Zhaohui Li,Lingbo Qu,Runping Han
Several pollutants found in industrial wastewater , such as Congo red dyes (CR), have been shown to be toxic to organisms. To protect human health and the environment, industrial effluents must be purified before being released into bodies of water. In order to effectively remove CR from the solution, amino functionalized walnut shells (WNS) were synthesized. Batch and fixed-bed column systems were used in this research. The Langmuir isotherm model fits the experimental findings well in these two systems, whereas the pseudo-second-order and Thomas kinetic models characterize batch and column CR adsorption, respectively. The adsorption capacity of ACWNS toward CR was to 224.4 mg g −1 at 303 K from Langmuir model. Electrostatic interactions and hydrogen bonding may be the mechanisms. The column research showed that adsorption was more favorable at low inlet solution concentration, low flow rate, or high column depth. The column mass transfer capacity parameter (B) increased with increasing concentration (0.461, 1.59, and 2.47 for 50, 100, and 150 mg L −1 , respectively) owing to a greater driving force for CR adsorption onto ACWNS, while adsorbate–adsorbent affinity (β) exhibited a reverse trend. The regeneration property of CR-loaded ACWNS was excellent using NaOH solution. The thermodynamic study revealed that CR removal was both spontaneous and endothermic. ACWNS is promising to remove CR from the solution.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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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
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 7
·1130
·
IF 3.164
Dingyuan Zheng,Yangyang Zhang,Yunfeng Guo,Jinquan Yue
Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55–82 nm and a width of 49–81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.Keywords:Walnut shell;nanocellulose;TEMPO oxidation;sulfuric acid hydrolysis;ultrasonication
研究领域:
材料科学
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农业废弃物利用
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
Journal of CO2 Utilization
·
2019
·
IF 5.189
Zhixiu Yang,Guojie Zhang,Ying Xu,Peiyu Zhao
This study offers a simple, environmentally friendly, and low-cost method to prepare N-doped adsorbents with outstanding CO 2 adsorption property under 1 bar. Utilizing waste walnut shell as adsorbents precursor and NaNH 2 as chemical activator and nitrogen source, porous adsorbents containing nitrogen are prepared at low temperature zone 400–500 °C. Also, by adjusting the activation temperature of the adsorbent and the ratio of NaNH 2 /AC, the pore structure and nitrogen content of the adsorbent are regulated to affect CO 2 adsorption performance. The specific surface area of the prepared series of nitrogen-containing porous adsorbents is from70 m 2 /g to 419–1721 m 2 /g. The result indicates that the optimal adsorbent has the highest 5.22 mmol/g of CO 2 adsorption capacity. A systematic study on the prepared series of adsorbents demonstrates that the narrow pore volume, pore structure and nitrogen content of the adsorbent jointly affected adsorption performance of CO 2 . Besides, these walnut shell-derived N-doped adsorbents show appropriate CO 2 /N 2 selectivity and Q st . The numerous advantages of the cheap waste walnut shell adsorbents enjoy simple and low-temperature synthesis process indicating that they are outstanding substitution to CO 2 adsorbents. The study hopes to further understand the synthesis of N-doped carbon and its carbon dioxide adsorption mechanism.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）