South African Journal of Chemical Engineering最新文献

{"title":"Exploring disintegration and swelling dynamics in Kappa-Carrageenan-based seaweed capsule shells","authors":"Maya Soraya,&nbsp;Hendrawan Laksono,&nbsp;Renny Primasari Gustia Putri,&nbsp;Ida Royanti,&nbsp;Dayu Dian Perwatasari,&nbsp;Rizky Aulia Prasasti Dewi,&nbsp;Heri Purwoto","doi":"10.1016/j.sajce.2025.04.015","DOIUrl":"10.1016/j.sajce.2025.04.015","url":null,"abstract":"<div><div>Kappa-Carrageenan or κ-Carrageenan-based seaweed capsule shells offer an appealing option for pharmaceutical formulations, particularly for vegetarian preferences. However, their disintegration kinetics present challenges for efficient medication release. This study investigates the disintegration dynamics of seaweed capsules, focusing on the swelling mechanism and the influence of various disintegrants. κ-Carrageenan-based capsule shells incorporating Polyvinylpyrrolidone, Primogel, Croscarmellose sodium, and Sodium Carboxymethylcellulose were examined for swelling behavior and disintegration time. Results reveal deviations in swelling behavior, with added disintegrants altering the disintegration mechanism towards wicking. Notably, Primogel demonstrates a significant wicking mechanism effect, evidenced by its markedly lower swelling value compared to other disintegrants (949.944 %). Analysis of swelling kinetic parameters further elucidates distinct trends in the swelling behavior of capsules containing different disintegrants, suggesting that Primogel promotes a gradual water uptake, facilitating wicking within the capsule matrix. Furthermore, capsules with Primogel exhibit the lowest disintegration time among tested disintegrants, achieving 36 min and 21 s. The study also explores the impact of disintegrants on capsule shell coloration and surface morphology, crucial factors influencing consumer acceptance. In conclusion, the study underscores the relationship between swelling propensity and disintegration time, providing valuable insights for optimizing capsule formulations in pharmaceutical applications.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 96-102"},"PeriodicalIF":0.0,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867854","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":"High efficiency on resin photocatalysis: Study on application and kinetic mechanism using langmuir Hinshelwood Model","authors":"Restu Hikmah Ayu Murti,&nbsp;Muhammad Abdus Salam Jawwad,&nbsp;Khusnul Khotimah Ayuningtiyas,&nbsp;Euis Nurul Hidayah","doi":"10.1016/j.sajce.2025.04.013","DOIUrl":"10.1016/j.sajce.2025.04.013","url":null,"abstract":"<div><div>This study aims to evaluate the effectiveness of Resin Immobilize Photocatalyst on reducing tofu waste water under the UV light, the resin is doped with two different semiconductor metals, ZnO and TiO₂. Resin Immobilization Photocatalyst Process (RIPT) was synthesized by impregnating resin and catalyst. In this study, RIPT was made with variations in catalyst weight to determine the effect of catalyst ratio. The primary focus of this study is the reduction of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) in tofu wastewater. A Langmuir-Hinshelwood kinetic model was used in the photocatalysis kinetic study to determine the reaction rate, in this study the resin capacity of each sample was also calculated. In RIPT-ZnO, the weight of the catalyst affects the reduction of BOD, the highest BOD reduction was obtained from RIPT with 30 g ZnO with a performance that can reduce BOD of tofu waste by 90.2 %, while in removing COD parameter RIPT-ZnO weighing 30 g can reduce 92.61 %. In RIPT-TiO₂ also shows the same trend, the more catalyst used, the greater the removal, whether in BOD or COD, sequentially the reduction in BOD and COD is 79.96 % and 85.29 %. The results of this study indicate that the use of RIPT with different catalyst ratios can effectively reduce BOD and COD in tofu wastewater, with ZnO showing superior performance compared to TiO₂.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 87-95"},"PeriodicalIF":0.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863516","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":"Developed a unique technique for creating stable gold nanoparticles (AuNPs) to explore their potential against cancer","authors":"Anas S ALmomani ,&nbsp;Ahmad Fairuz Omar ,&nbsp;Ammar A. Oglat ,&nbsp;Sarah Shakir Al-Mafarjy ,&nbsp;Mohammed Ali Dheyab ,&nbsp;Thair Hussein Khazaalah","doi":"10.1016/j.sajce.2025.04.012","DOIUrl":"10.1016/j.sajce.2025.04.012","url":null,"abstract":"<div><h3>Background</h3><div>Gold nanoparticles (AuNPs) are frequently employed in biomedical science because to their inertness, small size, stability, biocompatibility, large surface area, and low toxicity. The crucial problem, however, is to produce non-toxic and biocompatible AuNPs. Unlike chemically manufactured AuNPs, laser ablation synthesis provides a non-toxic, easy, and cost-effective alternative.</div></div><div><h3>Objective</h3><div>In this study, distilled water (DW) and Minimum Essential Medium (MEM) with phenol red are used to create small nanoparticles (NPs) with a narrower size distribution in highly stable colloidal NPs. The ability of these liquid media to replicate the spectral and size distributions of the synthesis of biocompatible AuNPs using laser ablation (LA) is also compared.</div></div><div><h3>Methods</h3><div>We determined the sample size using Transmission Electron Microscopy (TEM). The AuNPs were synthesised in liquid form by adding several materials and compounds from MEM with phenol red and DW. Then, a laser was used to irradiate the target and ablate the metal plate. A drop of colloidal AuNPs was applied to a silicon wafer, which was then dried in an air oven to determine the materials' microstructural characteristics using a Field Emission Scanning Electron Microscope (FESEM). Energy Dispersive X-ray Spectroscopy (EDX) was used to evaluate the materials' elemental makeup. Furthermore, MCF-7 cells grown in DMEM media were used to test the cytotoxicity of the AuNPs using the MTT assay.</div></div><div><h3>Results</h3><div>AuNPs in MEM with phenol red produced the smallest particles, size 8.84 nm at a wavelength of 532 nm, while AuNPs in DW produced particles size 16.3 nm at a wavelength of 1064 nm, as determined using TEM. These particle sizes were further confirmed by FESEM analysis, which showed closely comparable results, with AuNPs in MEM size 8.5 nm and those in DW size 18.6 nm. This difference is mainly due to physical and chemical properties and selecting a suitable laser wavelength with a limited absorption depth is critical to achieving efficient and rapid ablation with high-energy deposition in a small volume.</div></div><div><h3>Conclusion</h3><div>The non-toxic process of laser ablation can be used to create biocompatible AuNPs, which may find use in cancer treatment. In order to improve their efficacy in targeted cancer treatment, future research should concentrate on controlling parameters and investigating media.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 142-152"},"PeriodicalIF":0.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887199","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":"Characterization and evaluation of immobilized bimetallic and trimetallic nanoparticles fabricated using grape leaf extract and glass waste for cefixime removal","authors":"Teeba Salih Merjan,&nbsp;Ziad Tark Abd Ali","doi":"10.1016/j.sajce.2025.04.011","DOIUrl":"10.1016/j.sajce.2025.04.011","url":null,"abstract":"<div><div>Maintaining a clean and pollutant-free environment is an important issue for all living organisms, including humans, through the adoption of eco-friendly technologies that minimize ecological harm while enhancing sustainability. The present study was directed towards applying a green and eco-friendly approach in nanotechnology to develop sustainable solutions for pollution control and environmental remediation. The immobilization of bimetallic (Fe/Cd) and trimetallic (Fe/Cd/Cu) nanoparticles utilizing glass waste (G) as an inert support material was investigated in this work to produce two nanocomposites (G-Fe/Cd &amp; G-Fe/Cd/Cu, were employed to eliminate cefixime (CEF) from aqueous solutions. The grape leaf extract was used as a green antioxidant instead of harmful chemicals. Compared to the bimetallic nanocomposite, which showed a 26.23 mg/g capacity under optimal circumstances, the trimetallic nanocomposite had exceptional adsorption capability and a maximum CEF adsorption capacity of 32.51 mg/g. The adsorption kinetics were best characterized by the pseudo-second-order model, indicating chemisorption as the primary mechanism. The experimental adsorption data tightly matched the Freundlich isotherm model, showing a heterogeneous adsorption process. External mass transfer and intraparticle diffusion-controlled adsorption illustrate the efficiency and intricacy of the interaction processes. Negative magnitudes of ΔG° showed that the adsorption of CEF was spontaneous and thermodynamically beneficial; high ΔS° and ΔH° magnitudes indicated increasing randomness at the solid-liquid interface and an endothermic adsorption process. Moreover, copper's inclusion in the trimetallic system increases adsorption effectiveness by adding more reactive sites, thus enhancing surface characteristics and facilitating more efficient interaction with CEF molecules. This paper emphasizes the possibilities of nanocomposites as effective, sustainable, ecologically acceptable materials for eliminating antibiotic pollutants like CEF from aqueous solutions. These results provide important new perspectives for creating sophisticated adsorbents based on nanocomposites for wastewater treatment and environmental remediation.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 73-86"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863513","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":"A brief overview of hydrogen production and storage","authors":"Omotayo Sanni,&nbsp;Xoliswa Dyosiba,&nbsp;Jianwei Ren","doi":"10.1016/j.sajce.2025.04.009","DOIUrl":"10.1016/j.sajce.2025.04.009","url":null,"abstract":"<div><div>Given that the demand for hydrogen is predicted to grow by around eight times by 2050 compared to 2020, a number of factors may make it difficult to implement hydrogen applications successfully. Although storing hydrogen is still a major problem, it is seen to be one of the most promising alternative fuels replacing current fossil fuels. Technologies for hydrogen generation have emerged as a key component of the energy mix in a society that seeks to replace fossil fuels in order to reduce greenhouse gas emissions and address other environmental issues. Hydrogen is a clean \"green\" fuel of interest that can help achieve aggressive goals for reducing greenhouse gas emissions between 2035 and 2050. Currently used in industrial application, hydrogen compression and liquefaction are energy-intensive processes because they require low temperature (253 °C) and high pressure (30–70 MPa). Since chemical hydrogen storage allows for the safe storage of hydrogen-rich molecules in ambient settings, it is a possible substitute. Even though there are several molecules that are thought to be hydrogen transporters, some of them lackviable prospects for widespread commercialization. The present status of development of important areas of hydrogen production and storage technologies is reviewed, along with the advantages and disadvantages of each technique in relation to cost, efficiency, safety, and storage capacity. The safety implications of different H₂ storage methods have received particular attention because safety issues are one of the main obstacles to the widespread use of H₂ as a fuel source. This study also identifies the main obstacles and possibilities that the commercialization and development of hydrogen storage technology must overcome, such as the requirement for better materials, better system integration, and greater acceptability and awareness. From the reviewed literature, we have learned that when the challenges and constraints that are involved with the storage and production of hydrogen are adequately addressed, hydrogen will emerge as the first reliable source of energy. Secondly, thorough research on correct hydrogen processing designs will give an indication on the correct costing of these systems thus aiding in the minimization of operational and maintenance expenditures. Lastly, suggestions for further study and advancement with emphasis on bringing these technologies closer to commercial feasibility are reported. Therefore, policymakers, researchers, and scientists could utilize this review as a roadmap to help shape the future of hydrogen.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 60-72"},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860038","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":"Hybrid polyol-based polyurethane from pine merkusii resin and polyethylene glycol 400 for sustainable asphalt modification","authors":"Tamrin ,&nbsp;Sovia Lenny ,&nbsp;Misni Misran ,&nbsp;Ahmad Hafizullah Ritonga ,&nbsp;Mutiara Syaftiany","doi":"10.1016/j.sajce.2025.04.010","DOIUrl":"10.1016/j.sajce.2025.04.010","url":null,"abstract":"<div><div>Biopolymer-based materials have garnered significant attention as sustainable alternatives for asphalt modification. This interest stems from their ability to improve performance while reducing environmental impact. Conventional asphalt suffers from thermal susceptibility and aging, requiring modifications to enhance durability. Polyurethane-based modifiers, synthesized from polyols, have emerged as promising solutions due to their superior mechanical and thermal properties. This study reports synthesizing and characterizing hybrid polyol-based polyurethane using Pine Merkusii Resin (PMR) as a natural polyol and polyethylene glycol 400 (PEG-400) as a synthetic polyol for sustainable asphalt modification. The research involved three stages: (1) PMR polyol synthesis via oxidation using formic acid and hydrogen peroxide, (2) polyurethane preparation through the reaction of PMR polyol, PEG-400, and toluene-2,4-diisocyanate (TDI), and (3) asphalt modification using the synthesized polyurethane. Comprehensive characterization was performed using GC–MS, FTIR, swelling tests, DSR, TGA, and SEM. GC–MS confirmed the presence of α-pinene and β-pinene in PMR polyol, indicating a high hydroxyl content. The optimal polyurethane formulation (PMR polyol: PEG-400 polyol: TDI at 35.2:8.8:56) showed the highest crosslinking density and the lowest swelling index (5.69 %). FTIR analysis identified urethane network formation at 1630–1680 cm⁻¹. Rheological tests revealed that asphalt–polyurethane exhibited superior resistance to rutting and cracking under heavy loads and extreme temperatures compared to conventional asphalt. The asphalt–polyurethane blend (80:20) demonstrated the highest onset temperature (459.7 °C) and the slowest degradation rate, indicating excellent thermal stability. FTIR confirmed that polyurethane was well incorporated into the asphalt matrix, while SEM showed uniform dispersion and improved structural integrity. These results highlight the potential of hybrid polyol-based polyurethane as an eco-friendly and durable asphalt modifier.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 12-20"},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835259","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":"Characterization of Yamuna River water quality and its remediation by Phytoremediation technique","authors":"Bhanupriya Sharma ,&nbsp;Shobha Ram ,&nbsp;Sameer Vyas","doi":"10.1016/j.sajce.2025.04.006","DOIUrl":"10.1016/j.sajce.2025.04.006","url":null,"abstract":"<div><div>The Yamuna River in Delhi faces a critical environmental crisis due to escalating pollution levels. As per recent Delhi Pollution Control Committee reports, Delhi has 37 STPs with a combined treatment capacity of 566.3 MGD. However, with sewage generation reaching 792 MGD, approximately 225.7 MGD of untreated sewage is discharged directly into the river. This effluent significantly degrades water quality and poses a severe threat to aquatic ecosystems. The study assesses seasonal variations in the river's water quality, utilizing Box-and-Whisker plots and Hierarchical Agglomerative Clustering Analysis (HACA) to characterize spatiotemporal dynamics. In addition, the study explores the potential of phytoremediation techniques for restoring the health of the Yamuna River. Water samples were collected in three different seasons from eight sampling stations and nine parameters were determined viz., pH, temperature, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonia, and chloride. This study unveils the severe impact of pollution in the Yamuna River as drains mix into its water, causing zero DO levels. Box plots showed significant water quality degradation during dry seasons, with improvement in the rainy season. HACA optimized monitoring by identifying similar stations. Additionally, phytoremediation by Canna indica reduced TDS, ammonia, BOD, and COD levels, increasing DO from 0 ppm to 7.78 ppm, with over 95 % efficiency in removing BOD and COD when paired with aeration. The study introduces a cost-effective approach for remediating polluted stretches, emphasizing the critical role of multivariate statistical techniques in identifying key pollutants.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 49-59"},"PeriodicalIF":0.0,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860039","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":"Phycocyanin ultrasound assisted extraction from Spirulina (Arthrospira platensis) using sodium phosphate buffer solvent: Mass transfer modelling and stability test","authors":"Brilian Ryan Sadewo ,&nbsp;Rochmadi ,&nbsp;Nugroho Dewayanto ,&nbsp;Eko Agus Suyono ,&nbsp;Alinda Fitrotun Nisya ,&nbsp;Amare Nirwasita Parafianto ,&nbsp;Butsaina Masaroh Zulhan ,&nbsp;Arief Budiman","doi":"10.1016/j.sajce.2025.04.004","DOIUrl":"10.1016/j.sajce.2025.04.004","url":null,"abstract":"<div><div>Microalgae <em>Spirulina (Arthrospira platensis)</em> contains high protein content (55–70 %), consisting of approximately 20 % phycocyanin compounds as a photosynthetic pigment. Phycocyanin has antioxidant and anti-inflammatory properties. This study provides valuable insights involved mass transfer modelling and stability test of phycocyanin extract, leading to several important findings. Phycocyanin yield increases with temperature until 55 °C, beyond which denaturation reduces yield, highlighting the need for optimal temperature control during extraction. In the study at temperatures ranging from 30 °C to 50 °C, the mass transfer coefficients (kca) values ranged from 0.0229/min to 0.2592/min, the effective diffusivity (De)​ values ranged from 0.112 to 0.0519 cm²/min or 1.87 × 10⁻⁸ to 8.64 × 10⁻⁸ m²/s, and the equilibrium constants (K) values ranged from 106 to 572. The mathematical modelling of mass transfer phenomena was validated through comparison with experimental data, and all models showed R-squared (R²) values greater than 0.99, indicating a strong fit. Statistical analysis confirms temperature significantly impacts mass transfer parameters (kca, De, K) in phycocyanin extraction (<em>p</em> &lt; 0.05). Narrow confidence intervals for kca and De indicate high precision, while K shows greater variability, suggesting additional influencing factors besides the temperature. The mass transfer parameter constants increased with temperature due to enhanced molecular collisions, which accelerate solute diffusion and transport within the extraction medium. The degradation behavior of phycocyanin over seven days demonstrates that light exposure significantly accelerates the degradation process of bioactive compounds derived from microalgae. According to the kinetic modelling, the highest R² value among the three reaction rate models was observed for the first-order reaction rate equation, hence indicates that the first-order reaction rate equation accurately represents the degradation of phycocyanin pigment.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 103-116"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874416","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":"Integrated approach to elevating PES membrane performance with a dynamic silica and chitosan additive duo","authors":"Umi Fathanah,&nbsp;Cut Meurah Rosnelly,&nbsp;Zuhra Zuhra,&nbsp;Syawaliah Muchtar,&nbsp;Fachrul Razi,&nbsp;Wahyu Rinaldi,&nbsp;Yanna Syamsuddin","doi":"10.1016/j.sajce.2025.04.007","DOIUrl":"10.1016/j.sajce.2025.04.007","url":null,"abstract":"<div><div>Membrane fouling, low permeate flux, and the trade-off between flux and solute rejection remain pressing challenges in ultrafiltration processes, often compromising efficiency and selectivity. In this work, we highlight a novel dual-additive approach by combining silica and chitosan to enhance the performance of polyethersulfone (PES) ultrafiltration membranes. Membranes were fabricated via Non-Solvent Induced Phase Separation (NIPS) in which the modification was performed by blending technique using different combinations of these additives. The prepared membranes were characterized for their morphological structure, surface chemistry, porosity, hydrophilicity, tensile strength, pure water flux, solute rejection, and fouling resistance. The results demonstrate that the combined addition of silica and chitosan significantly improves membrane properties. Compared to single-additive modifications reported in recent studies, membranes modified with both additives showed an increase in porosity by up to 49.34 %, reducing the water contact angle to 61°, indicating enhanced hydrophilicity due to the enriched presence of hydroxyl groups. The modified membranes exhibited a remarkable 25-fold improvement in pure water flux (up to 57.8 L/m²·h) compared to the unmodified PES membrane, while maintaining a high solute rejection of 81 %. The flux recovery ratio of nearly 80 % highlights the enhanced fouling resistance. Overall, this dual-additive strategy offers a robust approach to tackle fouling and achieve a better balance between flux and selectivity, paving the way for more efficient ultrafiltration processes.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 1-11"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835260","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":"Assessment of nutrient and heavy metal contents in a sewage sludge treatment plant through hydrothermal carbonization","authors":"Tahmid Sadique Mazumder ,&nbsp;Rifat Mahmud ,&nbsp;Md Mominur Rahman ,&nbsp;Md Shahinoor Islam","doi":"10.1016/j.sajce.2025.04.005","DOIUrl":"10.1016/j.sajce.2025.04.005","url":null,"abstract":"<div><div>This study investigates the fertilizer potential of sewage sludge from a sewage treatment plant through hydrothermal carbonization (HTC) by assessing the nutrient and heavy metal contents. HTC was conducted at 190 °C, 210 °C and 230 °C at a constant retention time of 10 min maintaining a solid-to-water ratio (1:9), converting the dried sewage sludge (DSS) from the sedimentation basin into hydrochar and a nutrient-rich liquid phase. The organic nitrogen declined in the solids from 1.75 % to 0.89–1.46 % through HTC, whereas the ammonium-N increased (300–800 mg/kg). In the HTC liquor, 325–525 ppm organic nitrogen and 320–760 ppm ammonium-N were found. Hydrochars exhibited significant total phosphorus ranging from 1.95 % to 2.35 % and higher C:N ratio reaching 13.45 for 230 °C treatment indicating slow-nitrogen release property. Among other nutrients, 1.23–1.38 % calcium (Ca), 0.22–0.25 % sodium (Na) and 0.19–0.21 % potassium (K) were found in the hydrochar. On the other hand, 52.2–561.7 ppm phosphates, 210.4–498.5 ppm Ca, 48.19–51.35 ppm K and 28.63–84.40 ppm Na were incorporated within the HTC liquor. Among the heavy metals, the concentrations of arsenic (As), copper (Cu), zinc (Zn), nickel (Ni), cadmium (Cd), lead (Pb) and chromium (Cr) were assessed. Four (Cu, Zn, Ni and As) of the eight metals were found to be above the toxicity limit. However, in the liquor, the concentrations of heavy metals were negligible (&lt;2 ppm). Therefore, the study indicates that the use of sewage sludge has a potential to be used as nutrients for cultivating crops which will reduce the import of chemical fertilizer and enhance the utilization of sewage sludge sustainably.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"53 ","pages":"Pages 117-126"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878632","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}