South African Journal of Chemical Engineering最新文献

{"title":"Polynomial regression analysis on electromagnetohydrodynamic hybrid nanofluid flow over a rotating disk: Applications in next-generation thermal systems","authors":"Gunisetty Ramasekhar ,&nbsp;P.D. Selvi ,&nbsp;Hijaz Ahmad ,&nbsp;Waleed Mohammed Abdelfattah","doi":"10.1016/j.sajce.2025.12.010","DOIUrl":"10.1016/j.sajce.2025.12.010","url":null,"abstract":"<div><div>Thermal systems need effective cooling and heating processes, therefore thermal transfer innovation is critical in modern times, playing an important role in the manufacturing, aerospace, and electronic equipment sectors, in addition to automobiles and other modes of transportation. This study investigates the heat transfer properties of an electromagnetohydrodynamic mixed nanofluid across a porous spinning disk. The primary goal is to develop and validate an efficient engine oil/Cu-CuO hybrid framework that integrates traditional numerical approaches with polynomial regression analysis to accurately predict the flow and thermal features of complex nanofluid systems. The conversion of PDEs into ODEs is achieved by utilizing similarity variables. Thereafter, for graphical purposes, the study employed the bvp4c numerical method. The resultant structure is solved with the bvp4c scheme, and polynomial regression analysis is created to train the solution data for accurate estimation across different parameter (Q, Ec, Rd) settings. The suggested polynomial regression analysis has regression coefficients are 0.98, 0.87, 0.97, indicating high predicted accuracy and effectiveness. The influence of different parameters participating in the mathematical modeling is shown in various graphs and tables. In the result section the investigation noticed the velocity outlines increased, and on the other hand, there was a decreasing tendency in the energy outline for enlarging electric field parameter values. The heat generation and eckert number parameter values are increased, resulting in an improved energy profile. The results of this simulation have the potential to contribute significantly to more advanced study and research in the fields of bioengineering and bio-nanofluid dynamics.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 605-617"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924089","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}

{"title":"Manipulating calcination temperature on crystal structure and optical properties tuning of CuO nanostructures","authors":"Arrak Klinbumrung ,&nbsp;Reungruthai Sirirak ,&nbsp;Samor Boonphan ,&nbsp;Atit Wannawek ,&nbsp;Yanee Keereeta","doi":"10.1016/j.sajce.2026.01.002","DOIUrl":"10.1016/j.sajce.2026.01.002","url":null,"abstract":"<div><div>The research investigated the influence of calcination temperature on the properties of CuO nanostructures synthesized through a chemical precipitation method. Calcination at different temperatures (200, 400, and 600°C) significantly affected the crystal structure, morphology, and optical characteristics of the CuO nanostructures. Various characterization techniques were employed, including thermogravimetric analysis (TG), X–ray diffractometers (XRD), Fourier transform infrared spectrometers (FT–IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TG analysis revealed thermal behavior and phase transitions, while XRD results confirmed a monoclinic structure of CuO at 200°C with the calculation of the texture coefficient, crystallite size, lattice constants, strain, and other physical properties. SEM images showed a transition from nanorods to plate structures with increasing calcination temperature. TEM images demonstrated the highly crystalline characteristics of CuO samples. The BET analysis depicted surface area reduction, and CuO nanostructures exhibited energy band gaps ranging from 2.23 to 2.78 eV. Calculating optical terms as a function of photon energy also examined optical behaviors. Photoluminescence spectra revealed oxygen and copper vacancy defects, which sublevels affected energy bandgap change. The 400CuO sample exhibited the strongest PL emission signal, indicating the highest crystallinity and the lowest degree of defects. The findings underscored the significant impact of calcination temperature on the morphology and optical properties of CuO nanostructures, providing insights into their structural characteristics and emerging defects. The study supports opto-electronic applications and contributes to the global goal of pollution control and clean water.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 560-574"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924091","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}

{"title":"Physicochemical properties of banana leaves at different growth stages: Effects of bleaching and natural dyeing with lac, butterfly pea, and turmeric","authors":"Sopida Wisansakkul ,&nbsp;Orawan Oupathumpanont","doi":"10.1016/j.sajce.2025.11.004","DOIUrl":"10.1016/j.sajce.2025.11.004","url":null,"abstract":"<div><div>This research aimed to study the impact of bleaching and natural dyeing on the physicochemical properties of banana leaves at various stages of growth. Banana leaves were bleached and dyed using three natural dyes: lac, butterfly pea, and turmeric. The bleaching process reduced the moisture content from 66.05 % to 11.98 %–15.50 % and decreased the thickness and opacity of the leaves, while glossiness was not significantly affected. EDS analysis identified carbon, oxygen, silicon, phosphorus, and potassium as the five main elements present after bleaching. The color values of the leaves changed noticeably; the a* value shifted toward red, and the b* value toward yellow. Six-month-old banana leaves were found to be most suitable for dyeing due to their structure and dye absorption properties. When dyed, lac produced a dark red tone (L* = 61.14, a* = 3.95, b* = -2.90), and butterfly pea yielded a blue-green shade (L* = 62.40, a* = -1.00, b* = -4.60), and turmeric resulted in an orange-yellow hue (L* = 68.41, a* = 8.79, b* = 7.19). These findings suggest the potential of using naturally dyed banana leaves as sustainable, biodegradable materials for creative product design, particularly in eco-friendly fashion and lifestyle items such as handbags and backpacks.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 131-141"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517648","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}

{"title":"Toxic metal adsorption from gold tailings wastewater using biowaste biochars: A circular economy approach","authors":"Abudu Ballu Duwiejuah","doi":"10.1016/j.sajce.2025.10.006","DOIUrl":"10.1016/j.sajce.2025.10.006","url":null,"abstract":"<div><div>Sustainable development of adsorbents from biowaste and their use for the treatment of wastewater is a circular economy approach. The study assessed the adsorption efficiency of biowaste biochars for heavy metal ions from gold tailings wastewater. Fourier transform infrared spectroscopy (FTIR) was employed to identify the functional groups and bond vibrations in the biowaste biochar. A total of 100 mL of the gold tailings wastewater was measured into a conical flask, and biowaste biochar dosage of 1.0, 2.0 and 3.0 g each was weighed and added, and then kept in a water bath at 30 °C and agitated at contact times of 20, 35 and 50 min. The corn cob biochar removes Cd (99.10 to 99.40%), Hg (90.50 to 93.80%), and Cr (15.60 to 75.60%) and Ni (21.30 to 84.50%), peanut shell biochar removes Cd (99.10 to 99.40%), Hg (90.60 to 93.80%), and Cr (19.10 to 77.80%) and Ni (35.50 to 85.30%) whilst sheanut shell biochar removes Cd (99.10 to 99.40%), Hg (89.40 to 93.80%), and Cr (8.90 to 73.30%) and Ni (35.50 to 87.10%). Corn cob biochar showed K<em>_F</em> for Cd (3.4 × 10¹¹ to 1.8 × 10¹⁷ mg/g), Hg (1.8 × 10⁶ to 8.0 × 10¹² mg/g), and Cr (0.01 to 1.4 mg/g) and Ni (0.1 to 0.03 mg/g). The corn cob biochar contains primary alcohol, alkane and carboxylic acids groups, peanut shell biochar contains aliphatic, tertiary alcohol, amine and secondary amines, and sheanut shell biochar contains aliphatic, primary alcohol, amine and carboxylic acids groups. The biochar dosage increases the cadmium, mercury, chromium, and nickel adsorption efficiency onto biowaste biochars. The dosage, porous surface, and time increase the adsorption efficiency of cadmium, mercury, chromium, and nickel significantly. The Freundlich model was the best fit model for cadmium and mercury adsorption onto the biochars due to the heterogeneous surface of the adsorbent, which makes it have a tougher binding site. Biowaste biochars demonstrated considerable potential for effectively removing heavy metal ions from gold tailings wastewater, making a valuable contribution to the circular economy and the remediation of environmental pollution.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 83-91"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467801","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}

{"title":"Synthesis and characterization of nanocrystalline Mn-Zn ferrites obtained via hydrothermal method using Aloe barbadensis Mill (Asphodelaceae) extract for the treatment of water contaminated with Congo red","authors":"Melissa Quevedo Lopez ,&nbsp;Fernanda Pilaquinga ,&nbsp;Alexis Debut ,&nbsp;Alberto Albis Arrieta ,&nbsp;Andrés Rosales Rivera ,&nbsp;Zulia Caamaño De Avila","doi":"10.1016/j.sajce.2025.11.010","DOIUrl":"10.1016/j.sajce.2025.11.010","url":null,"abstract":"<div><div>Nanocrystalline ferrites of the Mn_1-xZn_xFe₂O₄ system (<em>x</em> = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized with varying Mn and Zn contents using a hydrothermal method assisted with <em>Aloe barbadensis</em> Mill (Aloe vera) extract as adsorbent materials in the treatment of water contaminated with an azoic organic dye (Congo red). The obtained nanoferrites were subjected to morphological, magnetic, optical and thermal characterization using SEM, XRD, FTIR, VSM, UV–Vis, DLS and TGA techniques. Nanocrystalline ferrites with a spinel-type structure and crystallite sizes ranging from 19.5 to 42.1 nm were obtained from XRD analysis. Morphological analysis by SEM revealed agglomerates of irregularly shaped particles with nanometric sizes. Magnetic hysteresis curves obtained by VSM showed the magnetically soft behavior of the ferrites, with saturation magnetization values ​​Ms between 37.89 and 8.78 emu/g, which decrease with increasing Zn content. UV–vis spectra confirmed that ferrites absorb primarily in the ultraviolet region and that the band gap energy increased with the addition of Zn. The Congo red dye adsorption tests showed that Mn-Zn ferrites perform well as adsorbents. Of all the compositions, the ferrite with <em>x</em> = 0.0 achieved a dye removal efficiency of 73.65 % across varying the concentration (25 ppm) and contact time (20 min). Likewise, this ferrite with <em>x</em> = 0.0 reached a maximum Congo red adsoprtion of 84 % at pH 5. Meanwhile, the ferrite with <em>x</em> = 1.0 achieved a dye removal efficiency of 74.84 % at pH 7. These results prove that Mn-Zn ferrites synthesized from Aloe vera extract represent a sustainable and efficient alternative for the treatment of water contaminated with the Congo Red dye.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 255-270"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621204","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}

{"title":"Computational modeling of peristaltic blood flow in a tapered channel with radiative heat flux and reaction mechanisms","authors":"S. Ravikumar ,&nbsp;Ali B.M. Ali ,&nbsp;Raghunath Kodi ,&nbsp;Ghulam Rasool ,&nbsp;Umid Turdialiyev ,&nbsp;Dilsora Abduvalieva ,&nbsp;M.Ijaz Khan ,&nbsp;Nidhal Ben Khedher","doi":"10.1016/j.sajce.2025.11.005","DOIUrl":"10.1016/j.sajce.2025.11.005","url":null,"abstract":"<div><div>The article demonstrates how computational methods help scientists study peristaltic blood flow and heat transport within biomedical systems. The present model uses peristaltic wave theory to build its framework while incorporating nonuniform boundary conditions. The channel walls show significant concurrence that matches real-world convective conditions. The established conditions enable researchers to study particle movement behavior which becomes essential for cardiac surgery applications. The mathematical model equations underwent transformation through lubrication techniques produced analytical solutions. The accuracy of present findings becomes evident through direct comparison with previously documented research results in scientific literature. The results match each other to a high degree. The hartmann number increase leads to an enhancement of fluid velocity according to this study. The hartmann number adjustment through external magnetic fields enables practical blood flow management which enhances medical device performance and drug delivery system accuracy. The Prandtl number decreases fluid velocity because viscous forces start to dominate thermal diffusivity. The relationship between these two parameters affects multiple fluid systems including blood flow in human bodies and various physical and biological systems. The heat transfer efficiency between conduction and convection increases when the heat biot number reaches higher values. The improved energy transfer leads to increased fluid velocity. The temperature profile shows significant changes because of thermal radiation effects. Medical biology depends on this parameter to optimize treatments through hyperthermia and study thermoregulation and create diagnostic and therapeutic equipment. The chemical reaction parameter strongly affects the concentration levels of the fluid. The knowledge of this relationship enables scientists to create improved therapeutic methods and enhance drug delivery systems and tissue engineering approaches. The chosen qualities are applicable in medical biology, biomechanics, heat exchangers, gas turbines, and several other fields.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 142-161"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577223","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}

{"title":"Process design for the continuous production of α- and γ-mangostin from mangosteen pericarp with integrated solvent recovery","authors":"Preuk Tangpromphan ,&nbsp;Amaraporn Kaewchada ,&nbsp;Attasak Jaree","doi":"10.1016/j.sajce.2025.12.008","DOIUrl":"10.1016/j.sajce.2025.12.008","url":null,"abstract":"<div><div>Mangosteen pericarp, a major agricultural by-product, is a rich source of xanthones, including α- and γ-mangostin, which possess significant anticancer and anti-inflammatory properties. This study details the continuous production process for these bioactive compounds, focusing on material and energy balance, performance parameters, and preliminary economic feasibility. The process includes material pretreatment, extraction, and separation using a three-zone simulated moving bed (TZ-SMB) system.</div><div>Extraction experiments were optimized to model the yield of α-mangostin based on temperature and solvent (acetonitrile) concentration. The optimal extraction conditions were found to be 40 °C and 65 % v/v acetonitrile, achieving a maximum yield of 70.49 mg/g of dried pericarp. For the separation process, models based on triangle theory were developed to determine the maximum feed flow rate for the TZ-SMB system while ensuring at least 98 % relative purity for both compounds.</div><div>A block flow diagram was used for material and energy balance calculations, performed in MATLAB. The wet mangosteen pericarp feed rate was varied to achieve the target xanthone concentrations required for the TZ-SMB design. At the optimal solvent recycle ratio of 90 %, the system demonstrated a daily production capacity of 477.65 mg for α-mangostin and 140.76 mg for γ-mangostin, with a favorable benefit-to-cost ratio. The economic analysis confirms the process's profitability, especially with solvent recovery. This work provides a foundational preliminary design, supporting strategic decision-making and laying the groundwork for more detailed process design using simulation software.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 460-474"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839566","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}

{"title":"Development and analysis of PVC glass slides for urine microstructure studies","authors":"Mohammed Alwan Farhan,&nbsp;Luma Salman Abd,&nbsp;Zaid H. Mahmoud","doi":"10.1016/j.sajce.2025.12.018","DOIUrl":"10.1016/j.sajce.2025.12.018","url":null,"abstract":"<div><div>The long-term maintenance of urine precipitation microstructures stays a main restriction in medical laboratory education and routine urinalysis, as traditional glass sides typically permit sample stability for only 1–3 h. In this work, a novel polyvinyl chloride (PVC)-coated glass slide system was advanced to capable long-term stabilization and microscopic conception of urine precipitation components. PVC films were functionalized with p-chlorobenzamidine (L) as photostabilizer to inhibit photodegradation induced via elongate exposure to UV light and microscope. The films photostability were systematically investigated employing FTIR, viscosity measurements, UV–Vis and FESEM analysis. At 365 nm, after 125 h of UV irradiation, the carbonyl index (Ico) for PVC+<em>L</em> films were increased to 0.13, compared with 0.18 of PVC, suggesting an essential reduction in oxidative degradation. The constant rate of photodegradation (kd) was reduced from 0.0021 s^-1 for pristine PVC to 0.0014 s^-1 for PVC+<em>L</em> sample, while the quantum yield of main-chain scission (Φcs) was decreased from 373×10¹³ to 884×10¹². Moreover, the PVC+<em>L</em> films preserved a higher viscosity-average molecular weight (Mv 260,000) contracted with the pristine PVC film after protracted irradiation, suggesting efficient inhibition of PVC chain scission. Functionally, at 295 nm, the PVC+<em>L</em> films appeared high (90 % transmittance) and cement clear microscopic conception of urine precipitation components. Cystine crystals, uric acid, calcium oxalate and triple phosphate, as well as amorphous materials, epithelial cells, kept optically distinguishable and morphologically intact for up to one year. These finds illustrate, for the first time, that photostabilized films can use as transparent, durable and chemically stable substrates for urine precipitation preservation, giving a low-cost and practical platform for routine microscopy, medical laboratory training and educational characteristics.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 575-585"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924178","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}

{"title":"Influence of silica addition in magnetite (Fe3O4) particles on physical properties for the application of nano-lubricant","authors":"Muhammadin Hamid ,&nbsp;Indri Dayana ,&nbsp;Habib Satria ,&nbsp;Dadan Ramdan ,&nbsp;Junaidi ,&nbsp;Muhammad Fadlan Siregar ,&nbsp;Dewi Sholeha ,&nbsp;Hadi Wijoyo","doi":"10.1016/j.sajce.2025.11.012","DOIUrl":"10.1016/j.sajce.2025.11.012","url":null,"abstract":"<div><div>The preparation of silica-coated magnetite nanoparticles as a lubricant additive has been successfully carried out. The material was prepared using a combination of coprecipitation and ultrasonic methods. In this study, SEM characterization was also performed to support morphological analysis, XRD was performed to determine crystalline properties, and FTIR analysis was performed to help identify functional groups. Based on these characterizations, the silica was successfully coated with magnetite. Then, AAS testing, Viscosity, and lubricant tests were conducted to assess the impact of adding silica-coated magnetite to the lubricant. The stability of lubricants using magnetite, both without and with the addition of TEOS, at a viscosity of 100 °C, is 8.65 mm²/s and 8.96 mm²/s, respectively, for lubricants and nano-lubricants. The total base number showed the exact value of 0.55 in both the lubricant and nano-lubricant, and the contaminant results obtained. In conclusion, additives can produce suitable nano-lubricants.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 238-243"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621231","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}

{"title":"Photoelectrocatalytic degradation of tetracycline by a novel Gr /Ni-Sb-SnO2 photo-anode","authors":"Heba F. Uonis,&nbsp;Ali H. Abbar","doi":"10.1016/j.sajce.2025.10.004","DOIUrl":"10.1016/j.sajce.2025.10.004","url":null,"abstract":"<div><div>The widespread use of pharmaceutical products in pharmaceutical therapies and agriculture has led to environmental pollution worldwide. In this work, a photoelectrocatalytic (PEC) process was applied for the degradation of a typical pharmaceutical product, tetracycline (TC), via a novel graphite (Gr)/Ni-Sb-SnO₂ photo-anode. The effect of nickel doping on the catalytic activity of the photo-anode was investigated with the help of XRD, SEM, AFM, and LSV techniques. The influence of several PEC parameters such as current density, pH, and initial concentration on the degradation of TC was studied and optimized using a response surface methodology (RSM). It was found that the Gr/Ni-Sb-SnO₂ (1:5:95) is the best photo-anode for TC degradation, and that increasing the nickel content above 1 % has a negative effect on the Gr/Ni-Sb-SnO₂ efficiency. RSM was found to be effective in describing the mathematical model linking PEC variables with TC removal at a correlation coefficient of 98.89 %. A significant interaction between the variables was observed in PEC, with the square term contributing 64.94 % to the model, and current density was the most important factor affecting TC degradation. The optimal conditions were a current density of 4.6 mA/cm², pH of 4.36, an initial concentration of 43 mg/L, and a time of 150 min in which a TC removal rate of 83.7 % was achieved corresponding to a COD removal of 62.3 % at a total energy consumption of 64.46 kWh/m³. A significant synergistic effect of PEC was observed, with rate constant being 1.56 times higher than that obtained for the photocatalytic process alone. In addition, the Gr/Ni-Sb-SnO₂ (1:5:95) photo-anode exhibited excellent degradation stability after five cycles of degradation test. Hence, Gr/Ni-Sb-SnO₂ (1:5:95) may serve as a good photo-anode for the photoelectrochemical treatment of industrial wastewaters.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"55 ","pages":"Pages 24-39"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145366028","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}