ABSTRACT Surfactant-stabilized water-in-oil emulsions, characterized by small droplet sizes and high stability, pose significant challenges for separation. Traditional demulsification techniques often require external energy and suffer from poor specificity, making the development of more efficient separation methods imperative. In this work, a three-dimensional material featuring micro/nano-scale hierarchical structures and a hydrophobic coating was fabricated via the facile functionalization of a melamine sponge with dopamine, hydroxy-terminated polydimethylsiloxane, and tetraethyl orthosilicate. The resulting superhydrophobic-superoleophilic material exhibited significant compressibility, with a water contact angle of 153.7° ± 1.1° and an underoil water contact angle of 159.9° ± 1.3°. The material attained a separation efficiency of 99.99% for immiscible oil-water mixtures. Moreover, an emulsion separation device was designed to evaluate the separation efficiency of the material. Even when separating various water-in-oil emulsions with extremely small droplet sizes and an oil-to-water ratio as low as 25:1, the separation efficiency remained consistently above 99.6%. Furthermore, the material demonstrated excellent reusability, maintaining high separation performance over 14 consecutive cycles. It also maintains excellent stability in high-salinity, THF, and weakly acidic and alkaline solutions, retains structural integrity after 24 hours of UV irradiation. Thus, the developed three-dimensional superhydrophobic material provides a straightforward, viable and energy-saving strategy for effective emulsion separation.

ABSTRACT Sulfur dioxide (SO2), a colorless gas with a distinctive pungent odor, is a significant air pollutant, primarily released from industrial processes and fossil fuel combustion. Its high reactivity and environmental impact, including contributions to acid rain, necessitate efficient capture and storage solutions. This study also aims to optimize SO2 adsorption by investigating the effects of flow rate, adsorbent weight, and contact time using Box-Behnken design within response surface methodology, as well as to evaluate the performance of individual (PKSAC, PKSX) and hybrid (PKSACX) adsorbents at various blending ratios to maximize removal efficiency. To overcome the limitations of each material individually, a blended series of PKSAC and PKSX was introduced to enhance SO2 adsorption efficiency. The Response Surface Methodology (RSM) with Box Behnken Composite Design (BBD) was employed to optimize two critical parameters: contact time and gas flow rate. Experimental findings showed that adsorption efficiency was maximized at lower flow rates and longer contact times, with the PKSACX blend achieving superior removal rates at optimal conditions. Statistical validation via ANOVA and visualization through contour and 3D surface plots highlighted significant parameter interactions, demonstrating that the 70:30 Xerogel-to-activated carbon blend achieved the highest SO2 removal efficiency. These results confirm the effectiveness of RSM-BBD in identifying optimal operating conditions and underscore the potential of PKSACX as a robust, sustainable adsorbent in industrial desulfurization processes. The removal efficiency of sulfur dioxide SO2 was significantly influenced by the blending ratio of palm kernel shell xerogel (PKSX) and palm kernel shell activated carbon (PKSAC). Among the investigated compositions, the PKSACX blend with a PKSX:PKSAC ratio of 70:30 exhibited the highest removal efficiency of 91%, surpassing the individual performances of PKSAC (84%) and PKSX (86%). This enhanced adsorption performance suggests a synergistic interaction between the porous carbon structure of PKSAC and the gel-based matrix of PKSX, which likely promotes improved surface accessibility and gas-solid interactions. A gradual decrease in removal efficiency was observed as the proportion of PKSAC increased, indicating that an optimal balance between the two components is critical for maximizing adsorption efficiency.

ABSTRACT This study provides an insight into the development of an economical and sustainable activated carbon derived from date seeds, modified with NaOH and HCl. The synthesized adsorbents efficiently remove Brilliant Cresyl Blue (BCB) and Coomassie Brilliant Blue R-250 (CBB) dyes. Microstructural changes at the surface of adsorption confirmed with the help of powder X-ray diffraction (PXRD), scanning electron microscope equipped with energy dispersive X-rays (SEM-EDS) and Fourier transform infrared (FTIR) techniques. BCB was removed within 20 min, upto 99.8% by NaOH activated date seeds carbon (OH-ADSC) at pH 6.2, while CBB were removed within 45 min, upto 99.7% by HCl activated date seeds carbon (H-ADSC) at pH 4.2. Both BCB and CBB dyes reveal monolayer adsorption with maximum capacity of adsorption (qmax) of 77.52 mg/g and 27.13 mg/g, respectively. The adsorption process was best described by the Ho and McKay model with R2 value 0.999 (BCB) and 0.997 (CBB). Thermodynamic study shows the endothermic (ΔHo = 31.92 and 20.46 kJmol−1 for BCB and CBB) and spontaneous nature (ΔGo < 0) of adsorption in both dye cases. Adsorption-desorption experiments reveal OH-ADSC and H-ADSC could be recycled/reused up to six times with removal efficiency of 82.4% (BCB) and 86.7% (CBB), making them efficient and reusable adsorbents. Agricultural waste valorization for environmental applications has gained significant attention as a sustainable waste management approach.

ABSTRACT Membrane biofouling persists not because we do not understand its mechanisms, but because diagnostic and intervention strategies are often misaligned with the stage of fouling. As a result, monitoring and control methods are typically applied without considering whether the adhesion is still reversible or has progressed to a more stable biofilm. In this work, we introduce a stage-specific framework that connects early physicochemical adhesion, extracellular polymeric substance (EPS) buildup, and quorum-sensing-driven maturation to the most appropriate diagnostic tools and control strategies. By comparing offline characterization, in situ imaging, and real-time monitoring techniques, we highlight true early-warning tools that can detect reversible attachment, as opposed to methods that mainly capture established biofilms. Our review of the available evidence shows that fouling reversibility is not only affected by biomass buildup but by the transition from surface-force-driven attachment to EPS-mediated biofilm consolidation and quorum-sensing-regulated resistance. Based on these insights, we suggest a stage-dependent approach to biofouling management: focusing on surface modifications and nutrient control during early adhesion, enzymatic and quorum-quenching treatments during matrix development, and more intensive physical-chemical methods for mature biofilms. The evidence supports that intervening early, before EPS consolidation occurs, is the most effective way to prevent fouling from becoming irreversible. When diagnostics and control strategies do not match, fouling accelerates, but combining stage-specific management techniques offers the best potential for long-term stability. This framework provides a clear path to translate laboratory-based diagnostics and antifouling innovations into practical, field-ready solutions.

ABSTRACT Pharmaceutical contaminants are increasingly detected in aquatic environments due to their widespread use, chemical persistence, and incomplete removal by conventional wastewater treatment processes. Photocatalysis has emerged as a promising advanced oxidation strategy for degrading these recalcitrant compounds, yet most existing reviews focus on model organic pollutants or general photocatalyst development, offering limited insight into pharmaceutical-specific behavior. This review provides a comprehensive and critical assessment of In2O3-based photocatalysts for pharmaceutical removal, emphasizing how intrinsic material properties and engineering strategies govern degradation performance. The influence of morphology, polymorphism, defect chemistry, doping, and heterojunction construction on light absorption, charge separation, and pollutant interaction is systematically analyzed. Particular attention is given to visible-light- and solar-responsive systems, including Z-scheme and S-scheme architectures, which consistently exhibit enhanced redox capability and improved degradation efficiency. By comparing performance trends across major pharmaceutical classes and identifying stability, scalability, and mechanistic limitations, this review establishes structure – activity relationships and highlights key challenges for practical implementation. The findings provide design guidelines for next-generation In2O3 photocatalysts and offer a pharmaceutical-centric framework to advance photocatalytic wastewater remediation under realistic conditions

ABSTRACT Chitosan (CS), a biodegradable and low-cost biopolymer rich in amino and hydroxyl groups, has attracted considerable attention in water treatment applications due to its ability to interact with a wide range of pollutants. However, its direct application is limited by low surface area, poor selectivity, and insufficient chemical stability. Advances in CS-based covalent organic frameworks (CS – COFs) and CS-molecularly imprinted polymers (CS – MIPs) have addressed these limitations by offering high porosity, tunable structures, and selective recognition capabilities. Nonetheless, conventional synthesis methods often rely on toxic solvents and energy-intensive processes, restricting scalability and environmental sustainability. Deep eutectic solvents (DESs) have emerged as promising green alternatives, providing biodegradable, tunable, and hydrogen-bond-rich media that facilitate eco-friendly dissolution, functionalization, and templating of CS-based adsorbents. This review summarizes recent modification strategies, adsorption mechanisms, and applications of CS – COFs and CS – MIPs for removing heavy metals, dyes, pharmaceuticals, pesticides, and other emerging contaminants. It further highlights the role of DES in promoting greener synthesis pathways and enhancing adsorption performance. Future research should emphasize DES-assisted synthesis of CS – COFs and CS – MIPs to enable environmentally friendly and scalable production, supported by life-cycle assessment, while promoting the development of multifunctional and regenerative CS-based adsorbents for sustainable water treatment.

ABSTRACT Environmentally relevant water matrices contain multiple organic contaminants, increasing complexity in multicomponent adsorption systems. This study investigates continuous fixed-bed adsorption of caffeine (CAF), atenolol (ATL), and propranolol (PRO) onto granular activated carbon (GAC) under single- and multicomponent conditions. Breakthrough data were analyzed using a Bayesian framework to model adsorption dynamics and quantify parameter uncertainty. Single-component experiments identified optimal conditions (C0POL = 60 mg.L−1, Q = 4 mL.min−1 and W = 0.5 g), achieving > 95% removal and capacities of 8.81 mgATL.gGAC −1 for ATL and 8.04 mgPRO.gGAC −1 for PRO, with saturation times of 66 and 52 min. In multicomponent operation, competitive adsorption reduced performance, yielding optimal time of 35 min with removals > 95% for CAF and ATL and 84% for PRO. Adsorption capacities decreased by ~57%, reaching 3.59 mgCAF.gGAC −1 (CAF), 3.93 mgATL.gGAC −1 (ATL), and 3.36 mgPRO.gGAC −1 (PRO), confirming distinct adsorption dynamics among the compounds. Logistic and Gompertz models described breakthrough curves, with Gompertz outperforming (R2 ≥ 0.97) by better capturing asymmetric S-shaped profiles. Bayesian analysis indicated faster breakthrough for CAF and ATL and delayed saturation for PRO due to stronger GAC interactions. Overall, empirical – Bayesian framework provides a robust and interpretable tool for multicomponent adsorption in fixed-bed water treatment under realistic conditions.

ABSTRACT This study investigated the recovery and recycling of a choline chloride–acetic acid deep eutectic solvent (ChCl–AA DES) used to extract ferulic acid from oil palm mesocarp fiber. Ferulic acid was recovered via selective precipitation with ethanol as an antisolvent, while the residual DES was treated and reused for up to five extraction cycles. The performance of recycled DES was evaluated by monitoring ferulic acid yield, solvent properties, and extraction efficiency. Ferulic acid yield from untreated recycled DES declined from 215 ± 11 mg/g to 78 ± 3 mg/g after five cycles. In contrast, DES treated with a second antisolvent showed improved retention of extraction efficiency, with yields decreasing from 215 ± 11 mg/g to 132 ± 3 mg/g over the same period. Supplementing recycled DES with fresh DES in 1:1 ratio did not enhance performance. Although the pH of recycled DES increased slightly across cycles, the change was minimal. A clear difference in viscosity was observed between water-treated recycled DES (≈7.05 mm2 /s) and untreated DES (≈20.95 mm2/s), though no significant changes occurred when the same treatment was applied consistently. Practical Applications: The study’s findings can be applied to develop an efficient solvent recycling system for DES extraction of ferulic acid from palm mesocarp fiber, making the process more cost-effective and environmentally sustainable while adding value to the oil palm.

ABSTRACT In this study, methylene blue (MB) adsorption onto tomato stem (TS) was comprehensively investigated, and the potential of TS as an effective biosorbent in wastewater treatment was examined. Additionally, the predictive power of the Artificial Neural Networks (ANN) model on the adsorption isotherms, kinetics, and thermodynamics was evaluated and compared with experimental calculations. The adsorption experiments were carried out in the batch system with MB solutions at various initial concentrations (20, 40, 60, 80, and 100 mg/L), temperatures (298, 308, and 318 K), and contact times (up to equilibrium). The adsorption kinetics were examined using nine different initial concentrations predicted by the ANN, and detailed kinetic analyses were performed at minute-level resolution. The ANN model successfully predicted the experimental results for untested concentrations and contact times. However, more experimental data were needed to conduct a rigorous thermodynamic analysis with the ANN model using an appropriate evaluation metric. The Langmuir isotherm provided good agreement at 298 and 308 K, while the ANN model showed a stronger correlation with the Temkin isotherm. The novelty of this study is the first comprehensive assessment of MB adsorption by the TS biosorbent by integrating the ANN model with both the adsorption equilibrium and kinetic analysis.