The growing global demand for oils and lipids, alongside the environmental impact of traditional oil crop cultivation, has generated significant interest in fermentation (or specifically precision fermentation) of oleaginous yeasts to produce food-grade bio-oils. While research is growing in upstream processing and innovation, downstream processing, which includes cell harvesting, disruption, oil extraction, and purification, remains underexplored. Current downstream methods are largely chemical based due to their high yields, established protocols, and operational simplicity. However, these current methods raise concerns regarding food safety and environmental sustainability. This review provides a comprehensive overview of these challenges across the various stages of downstream processing and examines their impact on process efficiency, sustainability, and scalability. The review also identifies key research gaps and proposes future research directions to advance the field and takes a whole-system approach to the sustainable production of food grade yeast oils. Furthermore, the review proposes novel research paths by analysing and drawing inspiration from oil recovery in biorefinery research. Developing efficient downstream processes for yeast-derived oils presents several challenges, including complex bio-separation steps, limited sustainable alternatives, high capital and energy requirements, scalability issues, and a lack of integrated process understanding. There are promising strategies from biorefinery research, such as innovations in solvents, novel adsorption techniques, advances in membrane technology and insitu conversion to finished products, which could be adapted (considering appropriate regulatory frameworks) to process food-grade yeast oils. The insights within this review aim to support the development of scalable, safe, and sustainable downstream processes to meet the rising demand for alternative oils.

Membranes are widely used in biomedical applications due to their efficient separations necessary for a variety of applications, ranging from pre-treatments to hemofiltration. These membranes often suffer fouling from high-concentration biological components, such as blood plasma proteins, which limits the separation performance. However, at research level, they are commonly tested using much lower feed concentrations that are not representative of real conditions. Developing and testing a membrane under high feed concentrations, analogous to those used during practical applications, its fouling resistance can be more realistically assessed. In this work, siloxene, an easy-to-synthesise hydrophilic, two-dimensional nanomaterial, was successfully incorporated as a filler into the polyethersulfone (PES) membrane matrix. At optimised filler loadings of 0.15 wt %, porosity rose to 83 %, zeta potential was enhanced to -35.4 mV and high hydrophilicity was achieved with a water contact angle as low as 27(degrees). Pure water permeance increased from 75 to 147 LMHBar, compared to PES, while rejecting similar to 99 % bovine serum albumin (BSA). Furthermore, the flux recovery ratio increased from 17 % to 62 %, therefore improving the use of effective membrane area. PES-siloxene membranes showed significant improvement in their capability to cope with concentrated biological feeds analogous to human blood plasma protein concentration: 80 g L-1 BSA solution. PES-Siloxene membranes also superseded the performance of commercial PES "protein-resistant" membrane and functionalised-graphene oxide in an equivalent matrix, highlighted in the literature for its protein antifouling properties. Overall, PES-siloxene MMM results in a lowcost, protein-resistant, and biocompatible membrane that maintains high selectivity suitable for biomedical applications.

This review explores the transformative potential of carbon nanotubes (CNTs) and their assemblies as next-generation materials for high-intensity beam diagnostics in particle accelerators. Thanks to their thermal conductivity, mechanical strength, and radiation resistance, CNTs offer substantial advantages over traditional materials used in high energy accelerator environments. The paper examines recent advances in CNT synthesis, purification, and fabrication techniques, assessing their performance under the extreme conditions imposed by high-intensity beams. It highlights experimental findings on CNT wire durability and thermal management, underscoring their promise not only for beam instrumentation but for a broad range of applications in these extreme environments. These developments open new options for tackling current challenges and directing future research for successful implementation.

Nanofiltration (NF) polymeric membranes are typically made from fossil fuel-derived feedstocks and toxic solvents, requiring a shift to more sustainable materials. This study pioneers the use of two biopolymers-cationic lignin and sodium carboxymethyl cellulose-as polycation and polyanion, respectively, to fabricate a polyelectrolyte membrane (PEM) via the layer-by-layer method with water as the sole solvent and on a poly(ether sulfone) (PES) support. At a transmembrane pressure of 2 bar, the pure water permeance was 6 LMHB (L/m2 h bar) for 5 bilayers with a 96% rejection for positively charged methylene blue and 93% for negatively charged reactive orange-16, with a mass balance above 90%, indicating minimal adsorption on the membrane surface. The molecular weight cutoff (MWCO) of the PEM ranged from 300 and 620 Da, corresponding to a loose NF membrane. Additionally, the PEM demonstrated excellent stability after 30 days in deionized water, attributed to strong electrostatic interactions between the polyelectrolyte layers. This study demonstrates that effective NF membranes can be produced using sustainable biopolymeric materials and benign solvents. The efficient rejection of small, charged molecules makes the PEM membrane promising for protein removal, wastewater treatment, biotechnology, and pharmaceutical applications.

Membrane distillation (MD) has the potential to tackle water scarcity challenges, as it can process non-traditional water sources to meet the growing water demand globally. However, long-term operation of MD systems is hampered by fouling of the membrane's surface which leads to reduced process efficiency. To address this, this study utilised 3D printed double sinusoidal (wavy) supports designed to enhance hydrodynamics at the membrane surface, mitigate organic fouling, and improve cleaning efficiency in air gap MD (AGMD). Computational Fluid Dynamics (CFD) simulations of turbulent water flow showed that wavy surfaces enhance surface shear stress and turbulent kinetic energy, reducing foulant deposition and facilitating foulant detachment during cleaning. Polyvinylidene fluoride (PVDF) hydrophobic films (thickness > 100 mu m) were attached to 3D printed flat and wavy supports via vacuum filtration, and their long-term AGMD performance was assessed. The composite membranes were tested continuously over 12 days using saline solutions containing humic acid, with a cleaning cycle every 3.5 days. A wavy membrane with a mixed matrix PVDF selective layer containing clay as a filler material, showed best-in-class performance, with a flux decrease of only 28 % and a flux recovery of 91 % before and after the third cleaning cycle, respectively. For comparison, a commercial PVDF membrane and an inhouse fabricated pristine PVDF membrane without any support, showed a flux decrease of 43 and 48 % and flux recovery of 65 and 60 %, respectively, confirming the CFD observations on the anti-fouling behaviour of wavy membranes. Overall, 3D printing allowed the fabrication of novel MD membranes with anti-fouling properties for long-term, efficient desalination and water treatment.

The increase in anthropogenic activities has led to the release of numerous chemicals and pollutants into aquatic ecosystems, raising significant concerns for water quality and health. Among the emerging issues is the interaction between pollutants and nanomaterials (mixture effects). In this work, it was studied the combined toxicity of boron nitride nanosheets (BNNS) and cadmium (Cd2+) incorporating the influence of natural organic matter (NOM) to enhance ecological relevance for the first time. Colloidal stability studies showed that BNNS is highly unstable, aggregating and precipitating over time in mineral reconstituted water. However, the addition of natural organic matter stabilizes BNNS. Acute toxicity results showed that this material has a good biocompatibility with D. magna, not causing acute toxic effect (immobility) even at high concentration (100 mg L-1). Moreover, when combined with cadmium, BNNS exhibited a "Trojan horse" effect, enhancing Cd2+ toxicity by facilitating its uptake at 1 mg L-1. 48h-EC50 values of Cd2+ and BNNS+Cd2+ were 0.21 and 0.14 mg L-1, respectively. Nevertheless, NOM (10 mg L-1) mitigated this combined toxicity effect after 48 h of exposure. These findings provide novel insights into nanomaterial-pollutant interactions linked to toxicological effects in aquatic environments, contributing to the risk assessment for the safe and sustainable development of the emerging boron nitride nanomaterials and novel products.

3D printed titania foams were used to degrade organic micropollutants in a photocatalytic flow reactor.

More efficient removal methods for per- and polyfluoroalkyl substances (PFAS), anthropogenic compounds with high persistence in the environment, are urgently needed due to their significant adverse health effects. Current technologies for PFAS removal in water are limited by incomplete degradation or practical concerns about the use of slurry-based adsorbents. In this study, self-supported indium oxide (In2O3) monoliths were produced via extrusion-based 3D printing and used for the removal of perfluorooctanoic acid (PFOA) via adsorption in a recirculating flow system. A detailed study of the sintering temperature, monolith geometry, and flow rate allowed maximising PFOA adsorption due to the improvement of PFOA diffusion and the increased number of active sites on the monolith, resulting in 53 % of PFOA removal with fast adsorption kinetics in 3 h. Additionally, a low-temperature pyrolysis process at 500 degrees C effectively regenerated the In2O3 monoliths, allowing reusing the monoliths for three adsorption cycles, while also improving the PFOA removal to 75 % in 3 h. The regenerated In2O3 monoliths not only have a high adsorption capacity (0.16 mg g- 1), but also required a much shorter time to reach the adsorption equilibrium compared with other adsorbents reported in the literature. The effectiveness, robustness and reusability of the 3D printed In2O3 monoliths highlight their potential as an efficient and sustainable adsorbent for PFAS removal. The approach presented here represents an effective strategy for the fabrication of complex adsorbents, which are reusable and can be easily handled, eliminating the expensive downstream removal required for slurries while offering a clear route for scale-up towards industrial use.

High-performance and sustainable membranes for water desalination applications are crucial to address the growing global demand for clean water. Concurrently, electrospinning has emerged as a versatile manufacturing method for fabricating nanofibrous membranes for membrane distillation. However, widespread adoption of electrospinning for processing water-insoluble polymers, such as fluoropolymers, is hindered by the reliance on hazardous organic solvents during production. Moreover, restrictions on industrial solvents are tightening as environmental regulations demand greener alternatives. This critical challenge is addressed here by demonstrating, for the first time, the fabrication of nanofibrous electrospun membranes of PVDF-HFP, poly(vinylidene fluoride)-co-hexafluoropropylene using a renewable, environment- and user-friendly solvent system containing Cyrene (dihydrolevoglucosenone), dimethyl sulfoxide, and dimethyl carbonate. The same solvent system was further used to produce nanocomposite graphene oxide (GO) and graphene nanoplatelet (GNP)-containing nanofibrous electrospun membranes. When tested for water desalination via membrane distillation, these membranes either outperformed or matched the performance of those produced with hazardous organic solvents, achieving salt rejection rates of >99.84% and long-term stability. The economic viability of the green solvent system was further validated through Monte Carlo simulations. This work demonstrates the potential to move fluoropolymer electrospinning from dimethylformamide-based systems to greener alternatives, enabling the consistent production of high-quality nanofibrous membranes. These findings pave the way for more sustainable manufacturing practices in membrane technology, specifically for water desalination via membrane distillation.

Tailoring the shape of porous ceramic tubes can improve the performance of several processes by enhancing fluid mixing and mass transfer and reducing fouling. Ceramics are, however, difficult to fabricate in complex geometries by conventional manufacturing methods. In this work, Digital Light Processing 3D printing of an acrylate-based resin containing an organometallic titania precursor was used for the first time to produce ceramic tubes in novel sinusoidal and twisted shapes, optimized with Computational Fluid Dynamics (CFD). CFD simulations of water in the laminar flow regime inside and around the tubes indicated improved fluid mixing by formation of vortices and fluid recirculation, increase of wall shear stress and enhancement of vorticity. Composite tubular structures with a 10 cm height and a wide range of design parameters (wavelength, peak amplitude, twist angle) were printed with a high resolution of 50 μm using resin containing 25% wt. titanium acrylate, while shorter structures could also be printed using 50% wt. titanium acrylate. The printed tubes maintained their sinusoidal or twisted shape after thermal post-treatment (de-binding and sintering) despite shrinkage of 35–45 % due to decomposition of the organic components of the starting material. The final sintered structures were made of pure titania and had a high porosity of 82 to 92 %. Overall, simulation-led design and 3D printing allowed for the production of porous ceramic tubes in unconventional shapes that have great potential to boost the efficiency of separation, contacting and catalytic processes.

Capacitive deionization is a promising and low-environmental-impact desalination technology that has gained significant momentum in recent years. This review presents a comprehensive analysis of hot topics in CDI, including electrode materials, cell architectures, selective ion removal, energy consumption, and salinity ranges. Improvements in CDI involve optimizing carbon materials through structural optimization, the introduction of surface functional groups, heteroatom doping onto nanocarbon materials, the modification of carbon materials with metal oxides, and the application of protective polymer coatings. Furthermore, a remarkable breakthrough has emerged in the form of Faradaic materials, which has led to a transformative surge in the desalination capacity of CDI. The evolution of the CDI cell architectures from the static electrode to the flow electrode, achieved continuous production. These innovations in electrode materials and cell architectures have not only bolstered energy efficiency and enabled energy recovery but have also broadened the salinity range that CDI can effectively address. Future research should focus on understanding ion-selective mechanisms, enhancing electrode stability, optimizing hydraulic designs, and conducting comprehensive economic and environmental assess- ments. Addressing these areas will be crucial for advancing CDI technology, enhancing its scalability, and improving its practical application in various settings.

Environmentally persistent polystyrene or polyacrylic beads are used as supports in enzyme large-scale bioprocesses, including conversion glucose isomerization for high-fructose corn syrup production, hydrolysis of lactose, and synthesis of active pharmaceutical ingredients. In this paper, we report the development of a novel sustainable and scalable method to produce diaminated cellulose beads (DAB) as highly efficient alternative supports for industrially relevant lipases. Regenerated cellulose beads were grafted with diaminated aliphatic hydrocarbons via periodate oxidation and reductive amination. The oxidation step indicated that aldehyde content can be easily tuned through the reaction time and concentration of reactants. Reductive amination of dialdehyde cellulose was more efficient as the length of the diaminated hydrocarbon compound increased. Morphological analysis of DAB showed that cellulose chemical grafting enabled the preservation of the bead shape and internal structure upon freeze-drying. Enzymatic degradability studies demonstrated that chemical functionalization did not undermine enzyme cellulose hydrolysis. The addition of aminated moieties on cellulose dramatically increased absorption efficiency for all industrially relevant lipases used, reaching 100% for Thermomyces lanuginosus lipase (TLL). Storage and recyclability experiments demonstrated that enzymes were retained and recyclable for at least nine cycles, although the activity gradually declined after each cycle. Medium chain triacylglycerol hydrolysis in a SpinChem reactor using TLL immobilized on 1,6 DAB exhibited higher activity compared to acrylic beads (588 vs 459 U/g) suggesting that biodegradable cellulose-based materials could be a valid and attractive alternative to plastics carriers.

Filtration processes have been applied widely in food processing industry over the recent decades and could offer a viable alternative to the use of solvents in the decaffeination process, comprising low operational costs, high selectivities and mild processing conditions. This paper reports the development and evaluation of the fouling occurring in multiple filtration cycles during the selective reduction of caffeine from coffee brews comparing the performance of (i) a commercially available synthetic tight ultrafiltration (TUF) polyethersulphone (PES) membrane (GP95PP - Alfa Laval) and (ii) a self-made mixed matrix (MMMs) PES membranes (PSCD) fabricated in-house. The effec-tiveness and performance of the PES MMMs was benchmarked against the commercial 2 kDa PES membranes showing promising results. A cross-flow rig was operated at transmembrane pressures of 2-9 bar and cross-flow velocities (CFV) of 0.04-0.1 m/s at 25 degrees C. The flux decline and recovery along with changes in the key component rejection and resistances are reported for multiple fouling and cleaning cycles. PSCD exhibited a higher permeate flux of ca. 10.5 L m-2 h-1 compared to the GR95PP membranes, which exhibited a permeate flux of 6.1 L m-2 h-1 over the 29 h filtration period selected, at 9 bar and a CFV of 0.04 m/s. The rejection ratios of the GR95PP and PSCD membranes were monitored for three consecutive filtration cycles, and showed values ca. 30% and 35% for caffeine, > 90% and similar to 90% for both polyphenols & proteins, & similar to 80% for melanoidins, respectively. An effective cleaning protocol was reported, comprised of 0.5 wt% NaOH at 50 degrees C, exhibiting cleaning efficiencies (CE) > 99%. FT-IR data indicated the presence of key compounds residuals after membrane cleaning. Modification to the membrane surface occurs due to fouling, altering the hydrophobicity. Differences in fil-tration performance and cleanability between the two classes of membranes are identi-fied and linked to variations in surface and structure properties.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creative-commons.org/licenses/by/4.0/).

Photocatalytic foams can concomitantly overcome the disadvantages of slurry and immobilized photocatalysts in water treatment. However, foams have, so far, been restricted to nanoparticles grafting onto inert foam substrates, with the consequent risk of nanoparticle release into the environment. In this work, self‐supporting, highly porous photocatalytic zinc oxide (ZnO) foams are produced using a combination of liquid templating and sintering for the first time. Systematic changes in sintering times and temperature affect the foams’ morphology and structure, in turn controlling their photocatalytic activity and stability. Sintering at 900 °C and decreasing sintering times from 20 to 6 h lead to a doubling in surface‐area‐to‐volume ratio and a 30% increase in pore diameter, resulting in a near doubling of the overall quantum yield and degradation kinetics. However, photocorrosion and Zn leaching increase markedly for the shortest sintering time. Optimal sintering conditions at 900 °C for 12 h yield foams capable of effectively degrading the model micropollutant carbamazepine under UV irradiation with high stability, showing no performance decrease over five irradiation cycles corresponding to 20 h of use. This study paves the way to producing self‐supporting, highly stable photocatalytic foams for the removal of organic micropollutants in water treatment.

Photocatalysis has proven to be highly effective for the removal of recalcitrant organic micropollutants at the lab scale. However, drawbacks such as the need for downstream removal of nanoparticle slurries and low surface areas of immobilised catalyst have, so far, hindered large-scale application. Photocatalytic foams have the potential to address these issues and advance the field towards large scale deployment. This review offers the first comprehensive overview of the state-of-the-art in this growing research field while simultaneously addressing two key issues which are slowing down further progress: The lack of classification nomenclature for foams, particularly regarding pore size and production method, and the use of kinetics as the defining feature of a photocatalyst, when alternate figures of merit, such electrical and quantum efficiencies, may be more appropriate. These were particular evident from a semi-quantitative comparison of the literature reported here, which highlighted the need for standardisation of experimental methods within the field. Finally future perspectives and best practices are discussed and recommended.

ZnO is a widely studied photocatalyst, but practical use is hindered by its low resistance to photocorrosion in water, which leads to metal leaching and loss of performance over time. In this work, highly porous and mechanically stable ZnO foams, called MolFoams, were doped by adding 1% or 2% Co, Ni or Cu salts to the starting Zn salt, followed by air insufflation during a sol-gel rection and sintering. The resulting doped foams showed a major increase in stability, with a 60-85% reduction in Zn2+ leaching after irradiation, albeit with a reduction in photocatalytic activity. A systematic analysis using XRD, Raman, XPS and XANES allowed for the identification of dopant species in the foams revealing the presence of Co3O4, NiO and Cu2O within the ZnO lattice with doping leading to a reduced band gap and significant increases in the resistance to photocorrosion of ZnO while identifying the cause of the reduction in photocatalytic activity to be shifting of the band edge positions. These results provide a pathway to significantly reduce the photocorrosion of ZnO in water, with further work required to maintain the photocatalytic activity of undoped ZnO.

Activated carbon fibres (ACFs) are successful electrode materials for capacitive deionization (CDI) owing to their excellent electrochemical properties and commercial availability, for example, with knitted or woven morphology patterns. However, the lack of a common and effective analytical framework to analyse the performance of ACFs is hindering further progress in the area. This study establishes an electrochemical impedance-based method to detect and investigate the electrochemical properties of ACF materials without destroying their original weaving patterns. Five commercial ACFs with two distinct patterns and similar specific surface areas were investigated. Data from electrochemical impedance spectroscopy (EIS) are compared to the desalination performance and energy consumption of the ACFs in a CDI cell. The weaving pattern played a role in the electrochemical properties and desalination performance. The volume-salt adsorption capacities in CDI were related to the volume-specific capacities in EIS, however, there was no significant difference between knitted and woven materials. Linked to EIS features, knitted ACFs consume less energy than woven ACFs for removing the same amount of NaCl from water. These results provide ACF researchers with a new, effective, and readily available approach for measuring the electrochemical performance of ACF materials via EIS.