Nanofiltration (NF) membranes are increasingly beingused to achieveprecise solute–solute separation. These membranes are commonlysynthesized using interfacial polymerization, offering great potentialto separate lithium from magnesium. In this study, we have developedmachine learning models that relate fabrication conditions, membraneproperties, and operational conditions of NF membranes to predictwater permeability and lithium/magnesium selectivity. Morgan fingerprints(MFs) and molecular descriptors (MDs) are used to represent the chemicaland physical properties of the monomers. Explainable artificial intelligencetools such as Shapley additive explanations (SHAP) and partial dependenceplots are used to evaluate the effects of the synthesis conditionsand membrane properties on membrane performance. Based on the insightsobtained from SHAP analysis, we developed a material screening approachto find promising monomers from a list of amines and cation-basedionic liquids. We construct a reference MF using the functional groupsthat positively contribute to membrane performance and compute a screeningscore that favors potential candidates with more desirable MDs. Finally,the synthesizability of these monomers is assessed using the syntheticaccessibility score to find the most promising candidates. We comparedthe performance of screened monomers against traditional ones to validatethe reliability of our approach. The results of this study providecritical insights into the relationships between synthesis conditions,membrane properties, and performance and establishes a novel, strategicframework for rational screening of monomers for NF membrane synthesis.This approach holds promise to accelerate the discovery of high-performancemembranes tailored for specific separation challenges, thereby advancingthe field of membrane technology.

Electrode behaviorwas elucidated during long-term galvanostaticelectrocoagulation (aluminum anode and aluminum cathode) of a hypersalineoilfield produced water rich in divalent cations. Electrode potentialsprogressively increased (i.e., fouling) for most operational conditionsdue to surface accumulation of calcite and brucite. The interfacialresistance resulting from partial insulation by electrodeposited saltswas quantified by using electrochemical impedance spectroscopy. Thepotential drop associated with this resistance correlated stronglyand positively with the increased overpotential required to maintainthe galvanostatic operation and was statistically indistinguishablefrom the calculated ohmic drop, confirming that electrode foulingcould be fully attributed to ohmic effects. This also ruled out theoccurrence of electrochemical side reactions at elevated potentials,despite their thermodynamic feasibility (note that H2(g) evolution is a non-Faradaic chemicalreaction). We evaluated polarity reversal (PR) as a fouling mitigationstrategy to restore electrode performance over a 4-fold variationin current density and a 100-fold variation in PR interval. The PRinterval did not significantly influence performance, and foulingwas effectively mitigated only at the highest applied current density(200 mA·cm–2). Results indicated the existenceof a threshold current density and associated hydrogen bubble generationrate necessary to effectively control electrode fouling under theexperimental conditions investigated. Foulant deposition also hinderedthe migration of electrodissolved aluminum ions away from the anode,facilitating their supersaturation, nucleation, precipitation, andentrapment, thereby decreasing the apparent Faradaic efficiency ofcoagulant dosing.

This study investigates the impact of loosely bound (LB-)and tightlybound (TB-) polymeric substances (PS) on bioflocculation and organicmatter harvesting in High Rate Activated Sludge (HRAS) systems, operatedwith primary effluent wastewater to specifically investigate the bioflocculationprocess. A pilot-scale HRAS system was operated at a contrasted solidsresidence time (SRT) of 0.2 and 0.8 d to assess the composition ofpolymeric substances extracted from the sludge (LB- vs TB-contents,biopolymers fraction), bioflocculation capacity, settleability, andthe fate of organic matter. Results demonstrate that a low SRT (0.2d) favors the accumulation of influent slowly biodegradable COD (morethan 60% based on COD mass balance) and of LB-PS with a limited biopolymercontent (<30%). The high LB-PS content observed at 0.2 d SRT (259± 15 mgCOD/gVSS) in turn hinders bioflocculation, resulting inthe formation of small and loose flocs and a higher loss of effluentsuspended solids. Conversely, sludge grown at 0.8 d SRT exhibiteda lower LB-EPS (116 ± 9 mgCOD/gVSS) content with a better bioflocculation,resulting in the formation of larger, more structured and fluffierflocs. A poor bioflocculation at low SRT hampered particulate andcolloidal organic matter removal, ultimately limiting the harvestingof organic matter despite an increased redirection. Overall, our resultsprovide relevant insights into the role of sludge composition (influentslowly biodegradable COD, LB-PS, biopolymers content) in the bioflocculationand resulting harvesting of organics in HRAS systems. Our resultsalso suggest that operation of HRAS systems at a very low SRT (e.g.,0.2 d) has the potential to increase the harvesting and valorisationof the organic matter of municipal wastewater but requires a bettercontrol of bioflocculation.

Plastic pollutionhas become a global environmental challenge,driving interest in enzymatic polyethylene terephthalate (PET) recyclingby using polyester hydrolases. In this study, we produced the PET-degradingenzyme PHL7 and its variant PHL7mut3 in Escherichiacoli and Pichia pastoris (syn. Komagataella phaffii) to investigatethe impact of N-glycosylation on enzyme properties. While glycosylationupon expression in P. pastoris enhancedthermal stability, it reduced the catalytic activity of the enzymes,revealing a trade-off that adds complexity to the selection of thebest-suited expression system. Additionally, we engineered P. pastoris to produce non-glycosylated enzyme variantsby substituting the asparagine residues (N) at all three putativeN-glycosylation sites with glutamine residues (Q). The non-glycosylated P. pastoris-produced enzymes showed a lower activitycompared to those produced in E. coli, likely due to the differences in the amino acid sequence. The effectsof glycosylation were less pronounced in PHL7mut3 than in PHL7, yetN-glycosylation strongly influenced the performance of both enzymes.We further demonstrate that the PET degradation performance of PHL7mut3is less dependent on the buffer ionic strength than that of PHL7.The study emphasizes the need for the informed selection of a suitableexpression host for polyester hydrolases to balance enzyme activity,thermostability, and production titer for applications in PET recycling.

Ozone, a strong oxidant, induces oxidative degradationin variousmaterials and is known as an effective chemical for polymer modification.This study assesses ozone as an alternative to chlorine oxidationfor converting end-of-life reverse osmosis membranes into nanofiltration-and ultrafiltration-like membranes across various new and used reverseosmosis and nanofiltration membranes. Membranes were characterizedin terms of permeability and salt rejection, as well as surface characterization.Experiments were conducted at high ozone exposure (20 ppm) and lowozone exposure (3 ppm). At high exposure, ozone was found to degradeboth the polyamide (PA) and polysulfone (PSf) layers, opening newpossibilities for polyester (backing layer) recycling. At low exposure,degradation was limited to the PA layer; ozone converted membranesmore effectively than chlorine, achieving similar performance in lesstime and at lower doses75 and 225 L·m–2·h–1·bar–1 for SW andBW membranes after 30 min at 3 ppm ozone, comparable to 6000 ppm chlorineover 50 h. Ozone significantly impacted NF90, raising the permeabilityto 150 L·m–2·h–1·bar–1 in 15 min at 3 ppm, while NF270 remained more resistantat 35 L·m–2·h–1·bar–1. Ozone caused patchy degradation due to bubble interactions,while chlorine led to uniform attack. These findings highlight ozone’spotential as a viable and more sustainable alternative to chlorinefor polymeric membrane transformation.

Recovering ammonia from wastewaterby membrane distillation(MD)is a sustainable approach to remediating environmental issues whilesimultaneously conserving energy both in wastewater treatment andin the Haber-Bosch process. MD leverages the volatility of ammoniato enhance ammonia transport, and hence its performance is impactedby the pH of the solution. We comprehensively investigated the effectof pH on ammonia transport and recovery efficiency using both experimentaland simulation approaches. Our analyses provide new insights intohow solution pH significantly impacts ammonia recovery through twoprimary mechanisms: it both governs the ammonia-ammonium equilibriumand influences the ammonia mass transfer coefficient. When changingMD feed solution pH from 9 to 10, ammonia flux is enhanced by 177%and ammonia mass transfer coefficient increases from 2.64 × 10–6 m·s–1 to 6.14 × 10–6 m·s–1. Notably, solution pHadjustment has a more significant effect than increasing solutiontemperature on enhancing the ammonia mass transfer coefficient andimproving recovery efficiency, making it a more feasible and effectiveapproach for improving ammonia transport and recovery. Additionally,our explicit simulations of ammonia recovery efficiency provide valuableinsights for optimizing MD performance by adjusting solution pH valuesand operation time, and enable a maximum profit estimation of $598,000for operating MD to recover ammonia in a dairy farm with 2000 cows.

Locally enhancedelectric field treatment (LEEFT) isan emergingtechnology that employs electric fields to inactivate bacteria inwater. Compared to traditional chlorine-based solutions, LEEFT allowsfor efficient water disinfection while preventing the formation ofharmful disinfection byproducts. When combined with copper (Cu), amaterial recognized for its antimicrobial properties, LEEFT-Cu hasdemonstrated increased bacteria inactivation efficiency. In this study,LEEFT-Cu is tested for its disinfection performance against 8 differentbacteria (4 Gram-negative (G−) and 4 Gram-positive (G+)), eachgrown in both stable and exponential phases. The primary focus ison the effectiveness of LEEFT-Cu against both gram structures. Itis concluded that LEEFT-Cu can achieve >3 log removal for mostbacteriaspecies (7/8) using <0.7 mg/L Cu. Additionally, the calculateddegree of improvement using LEEFT-Cu in comparison to Cu ions aloneindicates >20 times increase in disinfection performance. The degreeof improvement also leads to the conclusion that G+ bacteria are upto 3 times more vulnerable to the impacts of EFT (i.e., increasedmembrane permeability) than G–. Future work should focus ontesting the current bench-scale prototype with more complex watermatrices to further advance LEEFT-Cu for practical applications inwater disinfection.

Water scarcity remainsa critical global challenge, necessitatingthe advancement of sustainable water treatment technologies. Polymericmembranes have emerged as an indispensable solution for desalinationand wastewater treatment due to their high efficiency and low energyconsumption. However, conventional membrane fabrication relies onpetroleum-derived polymers and toxic solvents, generating significantenvironmental concerns. This review sheds light on the state-of-the-artapproaches to sustainable membrane development, focusing on greenchemistry principles and circular economy strategies. Mechanosynthesisoffers a solvent-free alternative for synthesizing advanced membranematerials, including metal–organic frameworks, covalent organicframeworks, and polymers of intrinsic microporosity. Additionally,the adoption of biobased green solvents, such as Cyrene and γ-valerolactone,provides viable substitutes for hazardous dipolar aprotic solventstraditionally used in membrane fabrication. The incorporation of biopolymers,including cellulose derivatives and polyhydroxyalkanoates, furtherenhances the sustainability of polymeric membranes. To mitigate membranewaste, circular economy strategies, including downcycling, upcycling,and repreparation via covalent adaptable networks, offer promisingpathways for extending membrane lifecycles and minimizing environmentalimpact.

Drinking water distributionsystems contain chlorine and metalsthat can promote antibiotic resistance. Corrosion inhibitors are requiredto prevent the leaching of metals into drinking water. While utilitieshave a choice of which corrosion inhibitor they employ, the impactof corrosion inhibitor type when combined with chlorine on antibioticresistance is unknown. The objective of this research was to understandthe impacts of zinc orthophosphate, sodium orthophosphate, and sodiumsilicate, three commonly used corrosion inhibitors, on antibioticresistance when mixed with chlorine. Culture-based plating was pairedwith metagenomics analysis on lab-scale microcosms. The addition ofall three corrosion inhibitors resulted in a significantly higherabsolute abundance of antibiotic resistant bacteria with resistanceto rifampicin, sulfamethoxazole, and vancomycin, while the additionof phosphate-based inhibitors (sodium orthophosphate and zinc orthophosphate)at 1 mg/L also resulted in significantly higher absolute abundanceof ampicillin-resistant bacteria. Exposure to all three types of corrosioninhibitors and free chlorine led to significantly higher abundancesof ARGs conferring resistance to the target antibiotics used in thephenotypic assessment. Observed changes in the resistomes comparedto the controls were influenced by an enrichment in ARGs responsiblefor multidrug resistance and resistance to peptide antibiotics. Ingeneral, most of the ARGs were associated with chromosomes, but asignificant increase in the number of ARGs colocated with plasmidand integron sequences was observed. In contrast, the abundance ofviral-associated ARGs decreased in the treatments compared to thecontrols. These results highlight the importance of corrosion inhibitorselection and the potential impacts on antibiotic resistance in potablewater systems.

Copper (Cu)-based catalysts have emerged as cost-effectiveandsustainable alternatives to noble metal systems (e.g., Pt, Pd) for catalytic CO oxidation. However, their practical applicationis hindered by insufficient low-temperature activity and rapid deactivationunder wet conditions containing moisture. To address these challenges,this work introduces CeO2-modified CuO/MgO-Al2O3 (Cu-Ce/MA) catalysts, strategically designed to enhancethe catalytic performance and water resistance simultaneously. Thesecatalytic materials were evaluated for CO oxidation under both dryand humid conditions, revealing that CeO2 modificationsignificantly improves the low-temperature activity. Specifically,the optimal catalyst, Cu-30Ce/MA, achieved a 50% CO conversion temperature(T50) of 151 °C, a marked reductionfrom 218 °C on Cu/MA reference catalyst. Furthermore, the waterresistance improves in a CeO2 content-dependent manner,with higher CeO2 loadings imparting greater stability inhumid environments. Detailed characterizations demonstrate that CeO2 promotes the dispersion of CuO and stabilizes Cu sites, whilealso enhancing the low-temperature reducibility and CO adsorptioncapacity. Crucially, CeO2 modification suppresses the competitiveH2O adsorption, mitigating water-induced deactivation.These synergistic effects collectively rationalize the superior activityand durability of Cu-Ce/MA catalysts. By elucidating the dual roleof CeO2 in optimizing Cu-based systems, this study advancesthe rational design of cost-effective catalysts for real-world COemission control, particularly under water-rich industrial conditions.