Research Articles (Chemical Engineering)

Permanent URI for this collectionhttp://hdl.handle.net/2263/1691

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Can batteries be fully sustainable?
Ojodun, Oluwasegun Emmanuel; Ren, Jianwei (Springer, 2026)
Concerns over the environmental impact, supply chain vulnerability, and long-term availability of conventional lithium-ion battery (LIB) materials have intensified interest in sustainable alternatives. This review defines a fully sustainable battery as one in which all components are derived from renewable materials and produced through eco-friendly processes across their entire lifecycle, consistent with the ISO 14044:2006 LCA framework. The current state of partially sustainable batteries is evaluated against this definition through a critical review of recent advances in biomass-derived carbon anodes, organic cathode materials, biopolymer gel electrolytes, cellulose-based separators, bio-derived binders, and carbonaceous current collectors across lithium-ion, sodium-ion (SIB), and aqueous zinc-ion (ZIB) battery chemistries. Key findings include the cost and carbon footprint competitiveness of biomass-derived hard carbon anodes with synthetic graphite ($1.72 kg−1 vs $4.97 kg−1; 3.2 vs 25.1 kg CO₂-eq kg−1), the ionic conductivity competitiveness of biopolymer gel electrolytes with conventional liquid electrolytes (up to 11 mS cm−1), and the consistent superiority of cellulose-based separators over commercial polypropylene in thermal stability, electrolyte wettability, and biodegradability. This review makes an original contribution by identifying four challenges that prevent the integration of these components into a fully sustainable battery. The costs, sustainability, and lifecycle assessments of LIBs, SIBs, and ZIBs are comparatively evaluated using available LCA data, and prospects for sustainable battery recycling are assessed. Based on this analysis, five research directions are proposed, with SIBs and aqueous ZIBs identified as the most viable configurations for fully sustainable batteries given their compatibility with bio-derived materials and lower lifecycle environmental impact.
Removal of nevirapine from wastewater using non-stationary continuous flow photocatalysis
Tabana, Lehlogonolo Shane; Tichapondwa, Shepherd Masimba (Springer, 2026-01-19)
This study explored the photocatalytic degradation of nevirapine (NVP), a widely used antiretroviral drug, using a continuous flow reactor system with an Ag-AgBr-LDH photocatalyst under visible light irradiation. The effect of light intensity was initially evaluated in batch mode, while the influence of photocatalyst loading, flow rate, and initial pollutant concentration was systematically assessed in continuous flow operation. Results indicated that higher light intensities enhanced degradation efficiency, confirming a strong correlation between photon availability and photocatalytic activity. The optimal performance was achieved with a photocatalyst loading of 3 g/L and a flow rate of 10 mL/min, resulting in the highest observed degradation efficiency. In contrast, elevated initial concentrations of NVP led to reduced degradation, likely due to light attenuation and increased surface adsorption that limited active site availability. A porous glass frit was employed at the reactor outlet to retain the suspended photocatalyst, ensuring continuous operation without material loss.
LiF-dominant SEI optimized by isomer effect for the regulation of Li deposition and LiPS-induced corrosion on Li anodes
Li, Haiou; Zhang, Han; Liang, Yangjie; Gu, Guanghui; Dong, Chenxin; Ren, Jianwei; Wang, Rongfang; Liu, Fusheng (Royal Society of Chemistry, 2026-07-30)
Severe corrosion of lithium metal anodes under high sulfur (S) loading conditions is a major contributor to the dissolution–deposition imbalance in lithium–sulfur (Li–S) batteries, ultimately accelerating cell degradation. To address this challenge, a LiF-rich solid electrolyte interphase (SEI) is in situ constructed on the lithium surface by introducing fluoropyridine as a functional electrolyte additive, enabling precise and effective anode protection. The resulting LiF-dominant SEI combines high compactness, favorable Li+ conductivity, and strong chemical stability, and operates through two synergistic mechanisms. On one hand, the SEI simultaneously provides physical separation and chemical passivation, effectively isolating lithium metal from lithium polysulfides (LiPSs) and suppressing corrosion reactions at their origin. On the other hand, the high ionic selectivity of LiF regulates Li+ transport, guiding uniform lithium deposition and improving the reversibility of lithium plating/stripping, thereby mitigating localized lithium depletion and deposition heterogeneity. Leveraging these advantages, the Li–S battery delivers exceptional electrochemical stability even under stringent operating conditions, such as a high sulfur areal loading of 5.0 mg cm−2 and a lean electrolyte regime (E/S = 8.0 µL mg−1), achieving an ultralow average capacity fading rate of only 0.07% per cycle. Moreover, a consistently high coulombic efficiency above 98% is sustained at a current density of 1C. Collectively, these findings confirm that the deliberate formation of a LiF-enriched solid electrolyte interphase effectively stabilizes the lithium metal anode, mitigates key degradation mechanisms, and markedly improves the long-term cycling performance of Li–S batteries.
Degradation of textile dye in industrial wastewater effluent and deionised water matrices using a Fenton-like Fe-BiOCl catalyst : synergistic effects and machine learning study
Hambali, Hambali Umar; Ogbeifun, Osemeikhian; Umar, Ahmad Abulfathi; Tichapondwa, Shepherd Masimba; Daramola, Michael Olawale; Iwarere, Samuel Ayodele (Springer, 2026)
Please read abstract in the article.
Rational design of BiOBr/ZnV2O4 Z-scheme heterostructure for efficient photodegradation of emerging contaminants triclosan under visible light
Oluwole, Adewumi Olumayor; Daramola, Michael Olawale; Iwarere, Samuel Ayodele (Elsevier, 2026-10-01)
Please read abstract in the article.
Design developmentof bimetallic clusters onto copper-benzimidazole metal-organic frameworks and their derived materials as electrocatalysts for water electrolysis and hydrogen fuel cell applications
Mothlathlo, Terrence; Ramohlola, Kabelo E.; Monama, Gobeng R.; Ren, Jianwei; Modibane, Kwena D. (American Chemical Society, 2026-07)
Please read abstract in the article.
Recent advances, emerging trends, and technology readiness level of ZrO2-based nanomaterials for the photocatalytic degradation of pharmaceutical pollutants
Emmanuel, Stephen Sunday; Adesibikan, Ademidun Adeola; Abimbola, Ebenezer Temiloluwa; Tichapondwa, Shepherd Masimba (Wiley, 2026)
Photo-enhanced advanced oxidation processes have attracted considerable attention for the removal of pharmaceutical pollutants from water. However, the development of efficient and sustainable photocatalysts remains a key challenge. This review examines recent advances in ZrO2-based nanomaterials (ZOBNs) for photocatalytic pharmaceutical degradation, with emphasis on degradation performance, reusability, and technological readiness level (TRL). The analysis reveals that ZOBN composites, particularly heterojunction-engineered systems, performed better compared with pristine ZrO2, with many of the reported ZOBN systems achieving >75% degradation efficiencies under optimized operating conditions. Enhanced performance is primarily associated with improved charge separation, defect engineering, oxygen-vacancy generation, and interfacial charge–transfer processes. Biosynthesized ZOBNs, ternary composites, and assisted photocatalytic systems were identified as promising material classes for improving degradation efficiency and stability. Reusability studies further indicate that many ZOBNs can retain up to 70% of their photocatalytic activity over 3–7 cycles, supporting their potential for practical application. Nevertheless, the technology remains at an early stage of development (TRL 1–4), and challenges related to real pharmaceutical effluent treatment, long-term stability, catalyst leaching, scale-up, and techno-economic feasibility continue to limit industrial implementation. Finally, key research priorities are proposed to facilitate the transition of ZOBN-based photocatalytic systems from laboratory investigations toward commercial wastewater treatment applications.
Compositional engineering of lignocellulose via selective delignification toward closed-pore-rich hard carbon for high-plateau-capacity sodium storage
Liao, Yunkang; Wang, Qi; Huang, Yongfa; Zhong, Linxin; Li, Tingzhen; Zou, Ren; Dai, Zhenhua; Iwuoha, Emmanuel; Ocakoglu, Kasim; Feleni, Usisipho; Ren, Jianwei; Peng, Xinwen (American Chemical Society, 2026-08)
Hard carbon derived from lignocellulosic biomass is a promising anode candidate for sodium-ion batteries due to its low cost and renewability. However, its practical application is limited by insufficient low-voltage plateau capacity, which is closely related to the closed-pore structure. Herein, we report a green and scalable compositional engineering strategy based on alkaline sulfite pretreatment, an industrially mature pulping process, to convert waste wood into closed-pore-rich hard carbon anodes. By selectively cleaving β-O-4 linkages in lignin, this pretreatment increases the relative cellulose content and fundamentally alters the carbonization pathway, yielding a highly disordered turbostratic structure. The optimized hard carbon (HHC-20) exhibits a doubled closed-pore volume (from 0.073 to 0.178 cm3 g–1) and an expanded interlayer spacing (0.385 nm). Consequently, HHC-20 delivers a high reversible capacity of 347 mAh g–1 at 20 mA g–1, with an outstanding low-voltage plateau capacity of 205 mAh g–1 and an initial Coulombic efficiency of 89.1%. In situ spectroscopic characterizations reveal a sequential sodium storage mechanism involving surface adsorption, interlayer intercalation, and pore filling. This work offers a sustainable and commercially viable pathway for designing high-performance hard carbon anodes for sodium-ion batteries.
Cannabis sativa L. biomass valorization as a strategic bioresource for South Africa’s circular bioeconomy: integrating biorefinery pathways and green extraction
Motsa, Lucia; Seedat, Naadhira; Mekuto, Lukhanyo; Sekoai, Patrick (Springer, 2026-07-13)
South Africa’s legalized Cannabis Sativa L. industry generates substantial biomass waste, including post-harvest materials such as stalks, leaves, roots, and seeds, as well as post-extraction residues rich in lignocellulosic components (cellulose, lignin, hemicellulose) and functional compounds (fibers, phenolic compounds, and proteins) which remain largely unvalorized. This review critically and systematically examines valorization pathways for Cannabis sativa L. biomass within the context of a circular bioeconomy, focusing on its potential as a bioresource amid South Africa’s evolving regulatory, agricultural, and industrial landscape. A systematic scoping review of 65 peer-reviewed studies (2018–2025) was conducted using international databases to evaluate biochemical and thermochemical conversion, integrated biorefinery strategies, and green extraction methods such as supercritical CO2 extraction, microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE). Compositional analysis indicates that lignocellulosic fractions from Cannabis sativa L., particularly bast fibers and hurds, are well-suited to cascaded biorefinery applications, enabling the recovery of cannabinoids, carbon-based materials, and bioenergy. However, several challenges persist, including biomass recalcitrance to enzymatic hydrolysis, inconsistent feedstock availability, and the lack of a standardized protocol within South Africa’s regulated environment. Techno-economic assessments (TEA) highlight the need for financial incentives, decentralized infrastructure, and cohesive policies among government entities, including DALRRD, SAHPRA, and DTIC. The review proposes a South African collaboration framework linking policy with research-based process design. Key gaps include the need for life cycle assessment (LCA) and TEA validation at the pilot scale, characterization of landrace cultivars, and development of accessible pretreatment technologies for smallholders.
Sustainable valorization of lignocellulosic biomass for integrated biofuel and biomaterials production within the circular economy framework : recent advances in pretreatment processes — a comprehensive review
Bezza, Fisseha Andualem; Tichapondwa, Shepherd Masimba; Brink, Hendrik Gideon; Daramola, Michael Olawale; Chirwa, Evans M.N.; Iwarere, Samuel Ayodele (Elsevier, 2026-12)
Lignocellulosic biomass is a promising renewable feedstock for the sustainable production of biofuels, biochemicals, and bioenergy, offering a viable alternative to fossil-based resources. Its efficient conversion is considered essential for developing resilient low-carbon energy systems. Integrated biorefineries, which combine diverse feedstocks with multiple conversion technologies, enable efficient valorization of all biomass fractions, thereby improving resource utilization, sustainability, and economic viability. However, lignin valorization remains a major challenge due to its complex and recalcitrant nature. This review critically examines recent advances in lignin-first valorization approaches, with particular emphasis on reductive catalytic fractionation (RCF) and hydrothermal liquefaction (HTL) for the production of value-added chemicals and fuels. Special attention is given to emerging hydrogen-free and self-hydrogen-supplied RCF strategies, including alcohol-mediated transfer hydrogenation systems, which reduce dependence on external hydrogen while improving process safety and economic feasibility. Recent developments in multifunctional and bimetallic catalysts are also discussed in relation to enhanced lignin depolymerization, selective bond cleavage, and suppression of lignin repolymerization. In addition, the review evaluates recent progress in pretreatment technologies and their roles in improving lignin accessibility, conversion efficiency, and overall biorefinery integration. The techno-economic potential of integrated biorefinery systems is critically assessed, focusing on process scalability, intensification strategies, and major cost drivers. Broader sustainability and socio-economic implications are also discussed. Finally, key challenges, including catalyst stability, hydrogen management, feedstock variability, and process integration, are identified, and future research directions are proposed to support economically viable, scalable, and environmentally sustainable lignin valorization pathways for next generation biorefineries. HIGHLIGHTS • Lignin-first approach enables high-value products such as sustainable aviation fuel. • Reductive catalytic fractionation (RCF) is a leading lignin-first valorization strategy. • Noble metal single-atom catalysts excel in RCF for phenolic monomer production. • HTL and RCF convert lignin into high-energy fuels and aromatic compounds. • Integrated biorefineries convert multiple feedstocks into diverse high-value products.
Negotiating virtually and face-to-face : experience from a serious game conducted in person and via smartphone application
Haneklaus, Nils; Horváth, Laszlo Simon; Brink, Hendrik; Brink-Flores, Kim; Kyomuhimbo, Hilda Dinah; Lee, Tzong-Ru; Misík, Matus; Roubík, Hynek; Kiselicki, Martin; Szabo, Patrícia; Guzsvinecz, Tibor; Sik-Lanyi , Cecilia (MDPI, 2026-03-29)
Serious games and negotiation simulations such as the Phosphorus Negotiation Game (P-Game) are increasingly used to support sustainability-oriented education. To broaden accessibility, a smartphone-based version of the face-to-face P-Game was developed and is presented here. A comparative design integrating quantitative pre–post survey measures with analysis of open-ended responses was employed to examine self-reported knowledge gains and learning experiences among participants who completed the P-Game in face-to-face workshops and those who played the virtual version. Both formats were associated with significant increases in participants’ perceived understanding of phosphorus science and negotiation science/practice. Self-reported knowledge of phosphorus science increased by 92.3% (global face-to-face), 70.7% (Hungarian face-to-face), and 88.4% (online), with comparable gains observed in negotiation science and practice across groups. Qualitative findings complemented these results, indicating that while learning gains were broadly similar, the modes differed in experiential emphasis: face-to-face delivery elicited performance-oriented and socially embedded reflections, whereas the online format was more frequently described in terms of structured participation and reflective processing. User satisfaction with the virtual P-Game was high, reflected by a System Usability Scale (SUS) score above 80. Overall, the findings suggest that the virtual P-Game represents a viable and accessible complement to traditional face-to-face implementation, maintaining educational impact while extending reach. Further research with larger and more diverse participant samples is recommended to strengthen generalizability and explore long-term learning outcomes in sustainability contexts.
Natural South African iron-rich sand as a functional catalyst in hybrid photocatalytic wet peroxide oxidation technology for the degradation of methyl orange dye pollutant
Ebrahim, Aaliyah; Emmanuel, Stephen Sunday; Dorling, Alicia Levana; Tichapondwa, Shepherd Masimba (Wiley, 2026)
Please read abstract in the article.
A review on photocatalytic degradation of hazardous polychlorinated biphenyls (PCBs) using nano-structured materials
Oluwole, Olumide James; Abimbola, Ebenezer Temiloluwa; Adesibikan, Ademidun Adeola; Emmanuel, Stephen Sunday; Tichapondwa, Shepherd Masimba (Wiley, 2026)
Polychlorinated biphenyls (PCBs) are persistent organic pollutants widely distributed in aquatic environments due to their chemical stability, hydrophobicity, and resistance to natural degradation. Their continuous release, coupled with long-term transportation, bioaccumulation, and biomagnification, poses serious ecological and human health risks, including carcinogenicity, endocrine disruption, and neurotoxicity. This review critically examines recent advances in the photocatalytic degradation technique for the removal of PCBs using nanomaterials. Emphasis is placed on the photocatalytic degradation performance, with reported efficiencies demonstrating significant potential. The reusability and stability of these nanomaterials are also discussed, highlighting their economic and practical viability. Furthermore, the effectiveness of these materials in complex real water matrices and industrial effluents was evaluated to bridge the gap between laboratory studies and real-world applications. Attention is also given to the ecotoxicological implications of PCB degradation intermediates, which may pose secondary environmental risks. Overall, the photocatalytic degradation technique emerges as a promising and sustainable strategy for mitigating PCB contamination, although challenges related to large-scale implementation and environmental safety remain.
High-electron-insulating Li2O-assisted Li3N for highly stable SEI formation in high-performance Li–S batteries
Liu, Hui; Wang, Hanxiao; Zhang, Boshen; Zhang, Jing; Wang, Min; Wang, Xuyun; Ren, Jianwei; Wang, Rongfang (American Chemical Society, 2026-07-06)
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In-situ preparation of Z-scheme Ag2WO4/FeVO4 heterostructure composite for tetracycline degradation : its performance and degradation pathway
Oluwole, Adewumi Olumayor; Nong, Jude; Tichapondwa, Shepherd Masimba; Daramola, Michael Olawale; Iwarere, Samuel Ayodele (Elsevier, 2026-10)
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Evaluating the effect of different types of dried automotive paint sludge as cement-based composite
Mavukwana, Athi-enkosi; Yapi, Litha; Molto-Berenguer, Julia; Nofemele, Zuko (University Amar Telidji of Laghouat, 2025)
In this project, we aim to probe four different automotive paint sludge (APS) types; primer coat, phosphate pretreatment coat, base coat and clear coat sludge, as potential additives in cement paste. Specifically, Portland Cement paste was doped with the different APS types which only underwent drying and milling on receipt from a vehicle assembly plant. The mixture was then cured for 7 days, and the resulting concrete was subjected to consistency, setting time, flexural strength and compressive strength tests. On comparison with the control cement paste, the primer coat sludge generally increased the setting time, by as much as 40 % for the final setting time. The compressive strength is negatively affected by the addition of all the different APS. This is somewhat mitigated if clearcoat sludge is used at a 1 wt.%: the difference is less than 10 % to the control. The phosphate pre-treatment coat is the worst performer with a difference of more than 90 %, even at a low APS concentration of 3 wt.% in the cement paste. In contrast, the flexural strength increases with the addition of all but one of the four APS types: phosphate pre-treatment coat. Primer coat sludge is associated with as much as 50 % increase in flexural strength. These results tentatively, show the utility of APS as an additive in cement paste to potentially tailor its properties, thereby decreasing the detrimental environmental impact of disposing of it. APS may also find application in refractory and clay brick manufacture.
A critical review of materials enhancing the performance of polymer membranes for membrane distillation of saline water
Nyembe, Nobuhle C.; Sadare, Olawumi; Daramola, Michael Olawale; Lokhat, David (MDPI, 2026-05)
Membrane distillation (MD) is an attractive complementary technology to conventional desalination systems. Yet commercial uptake remains limited by membrane pore wetting, temperature polarisation, and material trade-offs. This review critically examines polymeric membranes and demonstrates that reported performance gains cannot be attributed to individual polymers or fillers alone, but rather to optimised structure–property interactions governing wetting resistance, mass transfer, and mechanical integrity. Through a comparative analysis of benchmark metrics (water flux, contact angle, and liquid entry pressure), we identify recurring failure mechanisms, including nanoparticle agglomeration, coating instability, and hydrophobicity-driven compromises in liquid entry pressure and durability. Moving beyond a descriptive summary of materials, this review introduces a predictive structure–property–performance framework that systematically links dominant operational limitations and targeted modification strategies. The analysis reveals that surface-localised, adhesion-controlled modifications outperform bulk approaches by preserving pore architecture while mitigating fouling and wetting risks. Key research priorities include validation under high-salinity conditions relevant to brine management, standardised environmental and leaching assessments of nanomaterials, scalable fabrication protocols supported by techno-economic considerations, and developments on bioinspired materials. By shifting focus from material novelty toward rational design principles, this review establishes actionable selection criteria to accelerate the translation of MD membranes from laboratory concepts to industrially viable desalination technologies.
Effects of fire intensity on soil microbial ecology in a grassland ecosystem
Lebre, Pedro Humberto; Fouche, Jacques; Bosch, Jason; Pertierra, Luis R.; Varliero, Gilda; Frisby, Arnold Walter; Barker, Nigel; Greve, Michelle; Tichapondwa, Shepherd Masimba; Cowan, Don A. (Wiley, 2025-06)
In temperate grasslands, periodic or seasonal burning is considered critical for maintaining plant diversity and ecosystems. Under global change scenarios such as warmer and wetter climates and increasing alien invasions, fire is predicted to increase in intensity in many ecosystems. While the effects of fire on many terrestrial habitats (e.g., grassland, forest) have been extensively studied, less attention has been paid to the effects of fire intensity on the underlying soil microbiome. In this study, we used metagenomics, via 16S rRNA amplicon sequencing, coupled with functional assays and thermal profiling, to investigate the effects of increased fire intensity on the short‐ and medium‐term composition and functionality of grassland soil microbiomes. The results indicated that an increase in fire calorific output had a short‐term negative effect on soil microbial activity in grassland plots supplemented with plant biomass to simulate increases in fire intensity. In turn, the taxonomic profiling of soil microbial communities revealed that these plots were enriched in fast‐growing bacterial taxa 4 weeks after the fire event when compared to plots without biomass supplementation. This suggests that increased fire intensity exerts a medium‐term effect on the recovery of grassland soil microbiomes.
Digital simulation workshops to enhance student learning of chemical engineering thermodynamics
Luberti, Mauro; Rodgers, Thomas L.; Van der Gryp, Percy (Routledge, 2026)
Chemical Thermodynamics is a notoriously challenging course in Chemical Engineering programmes where several students struggle to grasp the rather abstract concepts and relate them to practical applications. At the same time, this subject has been highly impacted by digitalization as more complex thermodynamic models and simulation techniques have become increasingly available. This study evaluated the benefits of integrating digital simulation workshops grounded in Experiential Learning Theory (ELT) within our first-year Chemical Engineering Thermodynamics course at the University of Manchester. The workshops were designed to use the commercial Aspen Properties software as a rapid vapour–liquid equilibrium (VLE) generator. The workshops covered numerous aspects of VLE, including the selection of appropriate thermodynamic models such as equations of state and activity coefficient models, and the assessment of various diagrams for ideal, real and azeotropic mixtures, as well as high-pressure mixtures. A survey was carried out to gather the students’ opinions about the workshops structure, technical content, and perceived usefulness. It was found that our digital workshops coupling the use of interactive simulations with a problem-based learning approach not only promoted deeper engagement and critical thinking but also improved students’ academic performance in the final exam and their overall attitude towards the course.
Predicting environmental risks : using water balances for sustainable power at Kusile power station (South Africa)
Meyer, Amelia; Brink, Hendrik Gideon (Italian Association of Chemical Engineering, 2025)
Predictive water balances play a critical role in mitigating environmental risks in power generation by leveraging historical and real-time data for proactive resource management. At Kusile Power Station, these frameworks were used to identify a major environmental challenge and guide the development of an alternative wastewater management strategy. This study introduces a novel approach by integrating predictive modelling with a diffusion-based blending strategy, offering a cost-effective alternative to conventional chemical treatment methods. Instead of direct blending in pollution control dams, which was impractical due to high wastewater levels, a targeted blending strategy within the Flue Gas Desulphurisation (FGD) system was explored. A diffusion model confirmed that this approach could meet 53% of the FGD system’s water demand using wastewater, significantly reducing reliance on raw water. By incorporating these findings into the predictive water model, Kusile Power Station successfully optimized wastewater reuse, demonstrating the potential of data-driven strategies for sustainable industrial water management.

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