South African Journal of Chemical Engineering最新文献_第4页

Process design and performance analysis of a narrow-tubes circulating fluidized bed with a double-heat exchanger riser 双热交换器提升管窄管循环流化床工艺设计及性能分析

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-07 DOI: 10.1016/j.sajce.2025.12.006

Emad A.M. Abdelghani, Abdulwahab Aljuhani

Operating at high temperatures, highly exothermic catalytic reactors require high transfer rates and safer operating conditions to achieve high performance. Fixed beds, moving bed contractors, normal and even usual design assembly of circulating beds, cannot provide large areas suitable for extremely high heat transfer rates. This study presents a novel design of a circulating fluidized bed (CFB). The designed Narrow Tubes Circulating Fluidized Bed (NTCFB) was constructed and tested in cold-model experiments. The riser column of NTCFB consists of mainly two heat exchanges. A double concentric pipe heat exchanger in the bottom attached directly to the plenum and a shell-and -tube heat exchanger at the top that has a bundle of 69 narrow tubes with 6 mm inside diameter. The hydrodynamics behavior in the NTCFB was investigated, where experiments were carried out to examine the flow characteristics and hydrodynamic behavior of the NTCFB in terms of several operating parameters such as the pressure drop across the grid and the top shell-and-tube riser in the absence and the presence of bed particles. Very small pressure drops across the grid and top riser were noticed at high gas velocities as high as 8.0 m/s. Pressure drops were found to be <2.0 % of the atmospheric pressure for the two parts of the NTCFB. Besides, Gas-solid flow behavior was investigated in terms of solid circulation rates in the NTCFB. Fluidization runs smoothly without pressure fluctuations for large bed particles up to 2.5 kg loading, irrespective of gas velocity.

在高温下运行，高放热催化反应器需要高传输速率和更安全的操作条件来实现高性能。固定床，移动床承包商，正常甚至通常的循环床设计组装，不能提供适合极高传热率的大面积。介绍了一种新型循环流化床（CFB）的设计。设计了窄管循环流化床（NTCFB），并进行了冷模试验。NTCFB提升塔主要由两个换热器组成。底部的双同心管换热器直接连接到静压室，顶部的管壳式换热器由69根内径为6mm的窄管组成。研究了NTCFB的流体动力学行为，通过实验研究了NTCFB在没有和存在床层颗粒的情况下的流动特性和流体动力学行为，包括在网格和顶部管壳提升管内的压降等几个操作参数。在高达8.0 m/s的高气速下，通过电网和顶立管的压降非常小。压降为NTCFB两部分大气压力的2.0%。此外，从固体循环速率的角度研究了NTCFB内的气固流动特性。流态化运行平稳，没有压力波动的大床颗粒高达2.5公斤负载，无论气体速度。

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引用次数: 0

Experimental validation and multi-criteria decision optimization of parameters in gas hydrate-based desalination 天然气水合物脱盐工艺的实验验证及多准则决策优化

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-06 DOI: 10.1016/j.sajce.2025.12.005

Sirisha Nallakukkala , Abdulrab Abdulwahab Almashwali , Bhajan lal , Yaman Hamed , Jagadish Ram Deepak Nallakukkala

Gas hydrate-based desalination (GHBD) is a promising technology for sustainable water treatment, yet its practical implementation is often hindered by the slow kinetics and complexity of optimizing multiple process parameters. This study develops a robust decision-making framework using multi-criteria decision analysis (MCDA) to identify optimal conditions specifically volume, pressure, and stirring speed that enhance water recovery (WR) and moles of gas consumed. Experimental data were evaluated through MCDA based ranking methods to assess parameter performance. The results indicate that for CO₂ hydrate formation, the optimal conditions, 500 mL, at 3.0 MPa, provided a highest rank of 93 and stirring speed of 450 rpm with a rank of 32, produced a WR of 50%. In contrast, for CO₂+C₃H₈ hydrate systems in treating produced water (PW), at 2.0 MPa yielded the best performance with a highest rank of 39 and a WR of ∼60%. Unlike previous GHBD studies that primarily focus on feasibility and experimental characterization, this work introduces the first systematic MCDA based optimization framework for GHBD and provides experimentally validated optimal operating conditions. These findings highlight the importance of precise parameter selection and confirm the effectiveness of MCDA in guiding decision making for GHBD. This work introduces the first MCDA based framework for systematically optimizing operating parameters in GHBD. It uniquely shows that MCDA can reliably identify optimal CO₂ and CO₂ + C₃H₈ hydrate conditions, WR, efficient scalable desalination strategies, supporting long term environmental sustainability. and scalability of GHBD.

天然气水合物脱盐（GHBD）是一种很有前途的可持续水处理技术，但其实际实施往往受到动力学缓慢和优化多个工艺参数的复杂性的阻碍。本研究开发了一个强大的决策框架，使用多标准决策分析（MCDA）来确定最佳条件，特别是体积、压力和搅拌速度，以提高水采收率（WR）和消耗的气体摩尔数。通过基于MCDA的排序方法对实验数据进行评价，评价参数性能。结果表明，对于CO₂水合物的生成，最佳条件为500 mL， 3.0 MPa，最高等级为93，搅拌速度为450 rpm，等级为32，WR为50%。相比之下，对于CO₂+C₃H₈水合物体系在处理采出水（PW）时，在2.0 MPa下获得了最好的性能，最高排名为39，WR为~ 60%。与以往主要关注可行性和实验表征的GHBD研究不同，这项工作引入了第一个系统的基于MCDA的GHBD优化框架，并提供了经过实验验证的最佳操作条件。这些发现强调了精确参数选择的重要性，并证实了MCDA在指导GHBD决策方面的有效性。本文介绍了第一个基于MCDA的框架，用于系统地优化GHBD的运行参数。它独特地表明MCDA可以可靠地识别最佳CO₂和CO₂+ C₃H₈水合物条件，WR，高效可扩展的脱盐策略，支持长期的环境可持续性。以及GHBD的可扩展性。

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引用次数: 0

Experimental study on the effects of Maz Nitro additive on engine performance and emissions Maz硝基添加剂对发动机性能及排放影响的实验研究

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-06 DOI: 10.1016/j.sajce.2025.12.004

Pham Van Trong , Vinh Nguyen Duy , Hoang Dinh Long , Nguyen Minh Thang

This study presents a comprehensive experimental investigation into the effects of Maz-Nitro additives (Maz 100 for gasoline and Maz 200 for diesel) on engine performance, fuel consumption, emissions, and material compatibility under both laboratory and road test conditions in Viet Nam. The research utilized A92 gasoline with Maz-Nitro 100, composed of 65%-90% base Maz ingredients and 10%-35% OGA-72012 (a mixture of aromatic hydrocarbons and microelements), and 0.05% S diesel with Maz-Nitro 200, composed of 65%-90% original Maz ingredients and 10%-35% Di-tert Butyl Peroxide (improved ether oil). The test fuels were blended with Maz-Nitro according to standard procedures and evaluated using chassis dynamometers, constant volume sampling (CVS) systems, and real-world driving cycles. Parameters examined included brake power, fuel consumption, exhaust emissions (CO, HC, NOₓ, CO₂), lubricant degradation, and wear of key engine components. Results showed that Maz 100 significantly reduced CO (65.53%) and HC (27.22%) emissions and improved fuel economy by 9.8%, albeit with increased NOₓ and CO₂. Conversely, Maz 200 achieved simultaneous reductions in CO, HC, NOₓ, and CO₂ by 34.82%, 20.93%, 22.22%, and 6.93%, respectively, alongside an 8.2% reduction in fuel consumption. Additionally, the additives did not increase engine component wear, highlighting their potential for sustainable automotive applications by enhancing performance and reducing environmental impact.

本研究在越南的实验室和道路测试条件下，对Maz- nitro添加剂（汽油用Maz 100，柴油用Maz 200）对发动机性能、油耗、排放和材料相容性的影响进行了全面的实验研究。本研究使用的A92汽油为Maz- nitro 100，由65%-90%的基础Maz成分和10%-35%的OGA-72012（芳香烃和微量元素的混合物）组成，Maz- nitro 200为0.05%的S柴油，由65%-90%的原Maz成分和10%-35%的过氧化二叔丁基（改良醚油）组成。测试燃料根据标准程序与Maz-Nitro混合，并使用底盘测功仪、恒体积采样（CVS）系统和真实驾驶循环进行评估。检测的参数包括制动功率、燃油消耗、废气排放（CO、HC、NOₓ、CO₂）、润滑油退化和发动机关键部件的磨损。结果表明，Maz 100显著降低了CO（65.53%）和HC（27.22%）的排放，提高了9.8%的燃油经济性，但增加了NOₓ和CO₂。相反，Maz 200在CO、HC、NOₓ和CO₂的同时分别降低了34.82%、20.93%、22.22%和6.93%，同时燃料消耗降低了8.2%。此外，添加剂不会增加发动机部件的磨损，通过提高性能和减少对环境的影响，突出了它们在可持续汽车应用中的潜力。

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引用次数: 0

Sustainable synthesis of Ag and Cu nanoparticles using Quercus infectoria gall extract: A morphological perspective 利用栎瘿提取物可持续合成银和铜纳米粒子：形态学视角

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-05 DOI: 10.1016/j.sajce.2025.12.003

Oka Shinta Sekar Kirana , Zulfa Syaifana Muslih , Fatimah Nurus Shobah , Retno Purbowati , Ade Irma Rozafia , Afifah Rosyidah , Wahyu Prasetyo Utomo , Norazlianie Sazali , Djoko Hartanto

This research employed Quercus infectoria gall (QIG) extract as a reducing agent to produce metal nanoparticles (MNPs: Ag and Cu) and unveiled the reaction composition - MNPs morphology relationship. MNPs were synthesized by varying the volume ratio of metal ion solutions to QIG extract (1:1, 2:1, 4:1, and 8:1). Maximum absorption at specific wavelengths (Ag: 406–415 nm, and Cu: 320–325 nm) indicated the optimum formation of the AgNPs 8:1, and CuNPs 2:1. AgNPs were elongated and ellipsoid-shaped, while CuNPs were elongated block-shaped. The average size of AgNPs and CuNPs was 108 nm and 197.6 nm, respectively. The difference in the morphology and particle size of MNPs could be correlated with the reducibility of the metal ions and the presence of reducing groups (-OH) in the QIG extract. Metal ions with higher reduction potentials (Ag) tend to form more spherical MNPs due to the rapid reduction and nucleation of the MNPs. The ions with lower reduction potential (Cu) require a longer reduction time. This provides sufficient time for crystal growth, resulting in elongated particle morphology. This work provides a facile and sustainable strategy for designing MNPs with different morphologies.

本研究以栎瘿（Quercus infectoria gall， QIG）提取物为还原剂制备金属纳米粒子（MNPs: Ag和Cu），并揭示了反应组分与MNPs的形态关系。通过改变金属离子溶液与QIG提取物的体积比（1:1,2:1,4:1和8:1）来合成MNPs。在特定波长（Ag: 406 ~ 415 nm, Cu: 320 ~ 325 nm）的最大吸收表明AgNPs的最佳形成为8:1，而CuNPs的最佳形成为2:1。AgNPs呈细长椭球形，而CuNPs呈细长块状。AgNPs和CuNPs的平均尺寸分别为108 nm和197.6 nm。MNPs的形态和粒径的差异可能与金属离子的还原性和QIG提取物中还原基（-OH）的存在有关。具有较高还原电位（Ag）的金属离子由于MNPs的快速还原和成核，倾向于形成更球形的MNPs。还原电位较低的离子（Cu）需要较长的还原时间。这为晶体生长提供了充足的时间，从而产生拉长的颗粒形态。这项工作为设计具有不同形态的MNPs提供了一种简单而可持续的策略。

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引用次数: 0

Novel carbon-based photocatalysts for degradation of micropollutants 新型碳基光催化剂降解微污染物

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-03 DOI: 10.1016/j.sajce.2025.12.001

Neha Rajpal , Esther Naidoo , Ebrahim Kadwa , Sinethemba Xabela , Martina Dlasková , Olga Šolcová , Karel Soukup , Milan Carsky , David Lokhat

In this study, novel TiO₂ doped photocatalysts based on carbon foam derived from Typha capensis, a sustainable and naturally abundant biomass source, were prepared and evaluated for removal of an organic dye. The carbon foam was produced through a unique two-step process involving baking and carbonization, followed by chemical activation using either NaOH or HCl to improve its surface area, porosity, and surface chemistry. TiO₂ was then immobilised onto the activated carbon foam using a sol-gel method to enhance photocatalytic activity. The materials were extensively characterised, with BET surface area analysis showing a significant increase after chemical activation. The base-activated foam demonstrated the highest surface area. Microscopic analysis revealed a porous foam structure and confirmed the even distribution of TiO₂ particles on the carbon surface. X-ray diffraction analysis verified the presence of the anatase phase of TiO₂, which is known for its superior photocatalytic activity. Photocatalytic tests showed that the acid-activated carbon foam doped with TiO₂ exhibited the best performance, achieving a Rhodamine B degradation efficiency of approximately 19% under UV light. The superior activity is believed to stem from the improved surface chemistry introduced by acid activation, which aids TiO₂ dispersion and interaction with the pollutant molecules. This study highlights the potential of the novel carbon foam as a sustainable, low-cost, and potentially effective photocatalyst support for water treatment.

在本研究中，我们制备了一种新型TiO2掺杂光催化剂，该催化剂基于来自自然丰富的可持续生物质资源Typha capensis的碳泡沫，并对其去除有机染料进行了评估。碳泡沫通过烘烤和碳化两步工艺生产，然后使用NaOH或HCl进行化学活化，以改善其表面积、孔隙率和表面化学性质。然后采用溶胶-凝胶法将TiO2固定在活性炭泡沫上，以增强光催化活性。材料被广泛表征，BET表面积分析显示化学活化后显着增加。基活化泡沫的表面积最大。微观分析显示出多孔泡沫结构，并证实了TiO2颗粒在碳表面的均匀分布。x射线衍射分析证实了TiO2中锐钛矿相的存在，锐钛矿以其优异的光催化活性而闻名。光催化实验表明，掺杂TiO2的酸性活性炭泡沫表现出最好的性能，在紫外光下对罗丹明B的降解效率约为19%。优异的活性被认为源于酸活化引入的表面化学改善，这有助于TiO2的分散和与污染物分子的相互作用。这项研究强调了新型碳泡沫作为一种可持续的、低成本的、潜在有效的水处理光催化剂的潜力。

{"title":"Novel carbon-based photocatalysts for degradation of micropollutants","authors":"Neha Rajpal , Esther Naidoo , Ebrahim Kadwa , Sinethemba Xabela , Martina Dlasková , Olga Šolcová , Karel Soukup , Milan Carsky , David Lokhat","doi":"10.1016/j.sajce.2025.12.001","DOIUrl":"10.1016/j.sajce.2025.12.001","url":null,"abstract":"<div><div>In this study, novel TiO<sub>2</sub> doped photocatalysts based on carbon foam derived from <em>Typha capensis</em>, a sustainable and naturally abundant biomass source, were prepared and evaluated for removal of an organic dye. The carbon foam was produced through a unique two-step process involving baking and carbonization, followed by chemical activation using either NaOH or HCl to improve its surface area, porosity, and surface chemistry. TiO<sub>2</sub> was then immobilised onto the activated carbon foam using a sol-gel method to enhance photocatalytic activity. The materials were extensively characterised, with BET surface area analysis showing a significant increase after chemical activation. The base-activated foam demonstrated the highest surface area. Microscopic analysis revealed a porous foam structure and confirmed the even distribution of TiO<sub>2</sub> particles on the carbon surface. X-ray diffraction analysis verified the presence of the anatase phase of TiO<sub>2</sub>, which is known for its superior photocatalytic activity. Photocatalytic tests showed that the acid-activated carbon foam doped with TiO<sub>2</sub> exhibited the best performance, achieving a Rhodamine B degradation efficiency of approximately 19% under UV light. The superior activity is believed to stem from the improved surface chemistry introduced by acid activation, which aids TiO<sub>2</sub> dispersion and interaction with the pollutant molecules. This study highlights the potential of the novel carbon foam as a sustainable, low-cost, and potentially effective photocatalyst support for water treatment.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 358-367"},"PeriodicalIF":0.0,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unraveling the molecular recognition mechanism of voriconazole and functional monomers in molecularly imprinted polymer design 分子印迹聚合物设计中伏立康唑和功能单体分子识别机制的揭示

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-12-03 DOI: 10.1016/j.sajce.2025.12.002

Eko Adi Prasetyanto , Untung Gunawan , Dion Notario , Enade Perdana Istyastono , Meyliana Lukman Djaya , Shakira Aprillia Tanudjaja , Atthar Luqman Ivansyah

Molecularly imprinted polymers (MIP) offer highly selective recognition toward target analytes, yet their performance critically depends on the strength and nature of template–monomer interactions in the pre-polymerization stage. This study aims to develop a novel, integrative host-guest interaction approach that combines theoretical and experimental methodologies to support a rational MIP design framework. The computational elucidates the molecular recognition mechanism between voriconazole and monomers relevant to MIP formation, providing a detailed description of the complex stability and selectivity governed by non-covalent interactions. The interaction between voriconazole and 2-hydroxyethyl methacrylate (HEMA) was stabilized predominantly by hydrogen bonding and van der Waals interactions using a combination of energy analysis and electron density descriptors, supported by favorable binding energy and orbital overlap characteristics. Further investigation of multi-monomer complexes revealed that a 1:7 template-to-monomer ratio yields the most stable configuration, indicating cooperative binding effects. Non-covalent interaction analyses provided a comprehensive visualization of the domains of interaction and electron density features responsible for imprint specificity. Laboratory investigation, including the association constant and Job plot methods, confirmed the interaction of voriconazole and HEMA complex with a Ka value of 660±3729 M−1 and 1:7 template-to-monomer ratio at equilibrium in chloroform. These findings enhance the understanding of how non-covalent interactions govern the establishment of high-fidelity recognition sites and demonstrate the potential of computational assessments for the rational design of MIP, with implications for subsequent laboratory synthesis of MIP-based sensors.

分子印迹聚合物（MIP）对目标分析物具有高度选择性识别，但其性能主要取决于预聚合阶段模板-单体相互作用的强度和性质。本研究旨在开发一种新颖、综合的主客互动方法，结合理论和实验方法来支持合理的MIP设计框架。计算阐明了伏立康唑和与MIP形成相关的单体之间的分子识别机制，提供了由非共价相互作用控制的复合物稳定性和选择性的详细描述。伏立康唑与甲基丙烯酸2-羟乙基（HEMA）之间的相互作用主要由氢键和范德华相互作用稳定，利用能量分析和电子密度描述符的组合，支持有利的结合能和轨道重叠特征。对多单体配合物的进一步研究表明，模板与单体的比例为1:7时，构型最稳定，表明了协同结合效应。非共价相互作用分析提供了相互作用域和负责印记特异性的电子密度特征的全面可视化。实验结果表明，伏立康唑与HEMA配合物在氯仿溶液中的相互作用Ka值为660±3729 M−1，模板与单体的比例为1:7。这些发现增强了对非共价相互作用如何控制高保真识别位点建立的理解，并证明了计算评估对MIP合理设计的潜力，对后续实验室合成基于MIP的传感器具有重要意义。

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引用次数: 0

Optimization of PVP/PCL nanofiber diameter using coaxial electrospinning: response surface methodology and physicochemical characterization 用同轴静电纺丝优化PVP/PCL纳米纤维直径：响应面法和理化表征

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-11-29 DOI: 10.1016/j.sajce.2025.11.023

Ida Sriyanti , Muhammad Rama Almafie , Rahma Dani , Leni Marlina , Laida Neti Mulyani , Raisha Syafira Ap Idjan , Meutia Kamilatun Nuha Ap Idjan , Yuli Kurniawati

The electrospinning process offers a versatile platform for fabricating polymer-based nanofibers; however, precise parameter optimization is essential to achieve desirable morphology and performance. This study focuses on optimizing the coaxial electrospinning parameters for PCL/PVP nanofiber fabrication using Response Surface Methodology (RSM). A quadratic regression model was established to assess the combined effects of PCL concentration (10–15% w/v), PVP concentration (10–15% w/v), collector distance (120–160 mm), and applied voltage (12–20 kV) on nanofiber diameter. Statistical analysis confirmed the model’s robustness and predictive accuracy (p < 0.0001; R² = 0.9995; Adjusted R² = 0.9990; Predicted R² = 0.9983). The optimized condition yielded nanofibers with an average diameter of 526 nm and uniform morphology. Mechanical characterization indicated balanced tensile properties (tensile strength ∼10 MPa; elongation at break ∼5%; Young’s modulus 49–51 MPa), while surface wettability tests revealed improved hydrophilicity with a water contact angle of 70–79° FTIR analysis identified intermolecular hydrogen bonding between PCL and PVP, and XRD confirmed a semi-crystalline structure with crystallinity of 33–37%. The findings demonstrate that RSM is an effective statistical tool for process optimization in coaxial electrospinning, enabling systematic control over nanofiber morphology and performance. This optimized approach provides a reliable framework for designing composite nanofibers with tunable structural and physicochemical properties, supporting their potential use in biomedical and materials engineering applications.

静电纺丝工艺为制造聚合物基纳米纤维提供了一个通用的平台；然而，精确的参数优化是必不可少的，以达到理想的形态和性能。利用响应面法对PCL/PVP纳米纤维的同轴静电纺丝工艺参数进行了优化。建立二次回归模型，评估PCL浓度（10 ~ 15% w/v）、PVP浓度（10 ~ 15% w/v）、集电极距离（120 ~ 160 mm）和施加电压（12 ~ 20 kV）对纳米纤维直径的综合影响。统计分析证实了模型的稳健性和预测准确性（p < 0.0001; R²= 0.9995；调整R²= 0.9990；预测R²= 0.9983）。优化后的纳米纤维平均直径为526 nm，形貌均匀。力学表征表明拉伸性能平衡（抗拉强度~ 10 MPa；断裂伸长率~ 5%；杨氏模量49-51 MPa），表面润湿性测试表明亲水性得到改善，水接触角为70-79°，FTIR分析发现PCL和PVP之间存在分子间氢键，XRD证实了结晶度为33-37%的半结晶结构。研究结果表明，RSM是同轴静电纺丝工艺优化的有效统计工具，可以系统地控制纳米纤维的形态和性能。这种优化方法为设计具有可调结构和物理化学性能的复合纳米纤维提供了可靠的框架，支持其在生物医学和材料工程中的潜在应用。

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引用次数: 0

Synthesis and application of modified waste acropora coral skeletons for Pb(II) adsorption: A bead adsorbent perspective 改性废肢珊瑚骨架对铅（II）吸附的合成及应用——以头状吸附剂为例

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-11-26 DOI: 10.1016/j.sajce.2025.11.022

Anugrah Ricky Wijaya , Rahadian Zainul , Karna Wijaya , Niko Prasetyo , Nur Abdillah Siddiq

A novel class of bead adsorbents derived from waste Acropora coral skeletons, functionalized with various monomers including alginate, graphene oxide (GO), polyvinyl alcohol (PVA), chitosan, cellulose, natural silica, and pure silica, was synthesized, characterized, and evaluated for the adsorption of Pb(II) ions from aqueous solutions. The characterization techniques, including colorimetric analysis and FTIR spectroscopy, revealed characteristic absorption bands at 712.58, 1186, 825, 1470, 3562, 1660, and 1050 cm⁻¹, corresponding to functional groups introduced through modification of the coral skeleton using Ca²⁺ ions as a source. Among the synthesized beads, Ca-Alg-GO, Ca-Alg-PVA, Ca-Alg-Chitosan, and Ca-Alg-Pure SiO₂ exhibited a maximum adsorption capacity of 0.063 mg/g under optimized conditions namely, a contact time of 30 min and an initial Pb(II) concentration of 2 mg/L in batch systems. Kinetic analysis indicated that the adsorption data best fit the pseudo-second-order model (R²≈0.99), suggesting that chemisorption via valence forces involving sharing or exchange of electrons dominates the process. Additionally, the Freundlich isotherm provided a superior fit compared to the Langmuir model for Ca-Alg-PVA, Ca-Alg-GO, Ca-Alg-Celulose, and Ca-Alg-Chitosan beads, with R² values of 0.991, 0.998, 0.997, and 0.984, respectively. These results imply that multilayer adsorption occurs on heterogeneous surfaces. The positive ΔH values confirm that Pb(II) adsorption on these bead adsorbents is endothermic, reflecting strong interactions between Pb(II) ions and negatively charged sites on the bead surfaces.

利用海藻酸盐、氧化石墨烯（GO）、聚乙烯醇（PVA）、壳聚糖、纤维素、天然二氧化硅和纯二氧化硅等单体进行功能化，合成了一类新型头状吸附剂，并对其吸附Pb（II）离子的性能进行了表征和评价。通过比色分析和FTIR光谱等表征技术，我们发现了712.58、1186、825、1470、3562、1660和1050 cm的特征吸收带，与以Ca 2 +离子为源对珊瑚骨架进行修饰后引入的官能团相对应。在所合成的微球中，在接触时间为30 min，初始Pb（II）浓度为2 mg/L的条件下，Ca-Alg-GO、Ca-Alg-PVA、ca - alg -壳聚糖和Ca-Alg-Pure SiO 2的最大吸附量为0.063 mg/g。动力学分析表明，吸附数据最符合拟二阶模型（R²≈0.99），表明电子共享或交换的价电子力在化学吸附过程中起主导作用。此外，与Langmuir模型相比，Freundlich等温线对Ca-Alg-PVA、Ca-Alg-GO、ca - alg -纤维素和ca - alg -壳聚糖珠的拟合效果更好，R²分别为0.991、0.998、0.997和0.984。这些结果表明多层吸附发生在非均质表面。ΔH正值证实了铅（II）在这些球表面吸附剂上的吸附是吸热的，反映了铅（II）离子与球表面负电荷位点之间的强相互作用。

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引用次数: 0

Oxidative torrefaction of eucalyptus woodchips using a silica sand layer for bioenergy enhancement 利用硅砂层氧化焙烧桉木片增强生物能源

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-11-24 DOI: 10.1016/j.sajce.2025.11.019

Juan Pablo Arteaga-Ramos , Gabriel Alexandre-Pio , Millos Julian Enrique Jinete-Torres , José Claúdio Caraschi , Gretta Larisa Aurora Arce-Ferrufino , Ivonete Ávila , Carlos Manuel Romero-Luna

Due to the increase in energy demand in recent years, renewable energy sources have gained greater prominence, with biomass considered as the fourth source of renewable energy. In Brazil, a biomass of great importance is the woodchips generated by the industrial production of eucalyptus. Eucalyptus woodchips are mainly used as fuel in several industries, however, like other biomasses, they have some disadvantages such as low calorific value and high humidity. These disadvantages can be minimized by the torrefaction process. The literature has presented several options, one of which is oxidative dry torrefaction. Within oxidative torrefaction, there is a form where the biomass is immersed in a bed of inert material, however this form of torrefaction is still under study. In this work, sand-assisted oxidative torrefaction of eucalyptus woodchips is studied, evaluating the temperature in the range of 200 – 300 °C, the high of the mineral layer in 3, 6, 12 cm, and two times of torrefaction 30 and 60 min. The torrefaction temperature range was varied, in addition, variables such as time and height of the sand bed will be evaluated. The results obtained indicate that the yield of torrefied biomass is inversely proportional to temperature and time. Furthermore, the height of the sand bed has an influence on the yield and properties of the torrefied biomass. Sand-assisted oxidative torrefaction improves high heating value, reduces moisture content, and increases grindability.

由于近年来能源需求的增加，可再生能源得到了更大的重视，生物质能被认为是可再生能源的第四大来源。在巴西，尤加利工业生产所产生的木片是一种非常重要的生物质。桉树木片主要用作几种工业的燃料，然而，与其他生物质一样，桉树木片具有热值低、湿度大等缺点。这些缺点可以通过焙烧过程最小化。文献已经提出了几种选择，其中之一是氧化干燥干燥。在氧化焙烧中，有一种形式是将生物质浸泡在惰性物质床中，然而这种形式的焙烧仍在研究中。本文研究了桉木片的砂辅助氧化焙烧，评价了温度在200 ~ 300℃范围内，矿物层高度在3、6、12 cm，焙烧时间分别为30和60 min。在温度范围变化的同时，还对砂层的时间和高度等变量进行了评价。结果表明，碳化生物质的产率与温度和时间成反比。此外，砂床的高度对碳化生物量的产量和性能也有影响。砂辅助氧化焙烧提高了高热值，降低了水分含量，提高了可磨性。

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引用次数: 0

Advanced machine-learning frameworks for predicting malachite green adsorption onto superparamagnetic-activated carbon derived from Spathodea campanulata flowers 用于预测孔雀石绿吸附在鸡血花超顺磁活性炭上的先进机器学习框架

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2025-11-21 DOI: 10.1016/j.sajce.2025.11.017

Sujesh Sudarsan, Ramesh Vinayagam, Raja Selvaraj

This investigation introduces a comprehensive machine-learning (ML) scheme for accurately predicting the uptake of the cationic dye Malachite Green (MG) onto superparamagnetic activated carbon derived from Spathodea campanulata flowers. Batch adsorption experiments data covering a wide range of solution pH, sorbent dosage, initial dye concentration, contact time, and temperature were used to compare four predictive models: multiple linear regression (MLR), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and support vector machine (SVM). Pearson correlation analysis revealed contact time as the dominant positive factor influencing adsorption capacity (Q_e). Among MLR variants, the interaction-linear model achieved the best fit (R² = 0.8901). SVM with a medium Gaussian kernel improved accuracy substantially (R²= 0.9577). ANN delivered similarly strong predictive power (overall R² =0.9672) by learning complex multidimensional patterns. ANFIS emerged as the most robust and generalizable model, achieving R² = 0.9683 with the lowest mean squared error (0.0098), root mean squared error (0.0992), and mean absolute error (0.0311). Sensitivity analysis of the optimized ANFIS confirmed the primacy of contact time (56.8 %), followed by initial concentration (33.2 %), dosage (3.6 %), temperature (3.3 %), and pH (3.1 %). This integrated experimental–computational approach offers a scalable, data-driven strategy for designing magnetically recoverable adsorbents and optimizing dye remediation in complex wastewater matrices.

本研究介绍了一种全面的机器学习（ML）方案，用于准确预测阳离子染料孔雀石绿（MG）在从鸡花中提取的超顺磁活性炭上的吸收。批量吸附实验数据涵盖了广泛的溶液pH、吸附剂用量、初始染料浓度、接触时间和温度，并对多元线性回归（MLR）、人工神经网络（ANN）、自适应神经模糊推理系统（ANFIS）和支持向量机（SVM）四种预测模型进行了比较。Pearson相关分析显示，接触时间是影响吸附量（Qe）的主要因素。在MLR变量中，交互线性模型的拟合效果最佳（R2 = 0.8901）。中等高斯核支持向量机显著提高了准确率（R2= 0.9577）。人工神经网络通过学习复杂的多维模式也提供了同样强大的预测能力（总体R2 =0.9672）。ANFIS模型的鲁棒性和泛化性最强，R2 = 0.9683，均方误差最小（0.0098），均方根误差最小（0.0992），平均绝对误差最小（0.0311）。结果表明，接触时间（56.8%）、初始浓度（33.2%）、药量（3.6%）、温度（3.3%）、pH（3.1%）是最主要的影响因素。这种集成的实验计算方法为设计磁可回收吸附剂和优化复杂废水基质中的染料修复提供了可扩展的数据驱动策略。

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