The review, the first dedicated synthesis of wood-derived adsorbents specifically for pharmaceutical removal, catalogues four broad families of materials produced from timber and forestry waste: delignified wood sponges and aerogels, wood-derived biochar, wood-derived activated carbon, and functionalised wood and wood composites. Each exploits the same raw advantage. Wood is abundant, renewable, cheap and naturally hierarchical, composed of 40 to 45 percent cellulose, 20 to 35 percent hemicellulose and 10 to 30 percent lignin, all of which carry reactive hydroxyl and carboxyl groups that can be chemically decorated to tune adsorption behaviour. By weight, wood can also reach porosities above 90 percent and surface areas around 1,349 square metres per gram after processing, while hydrophobic surface treatments can push water contact angles to approximately 150 degrees, a combination that proves decisive for capturing organic drug molecules.

The performance numbers reported across the reviewed literature are striking. Engineered wood sponges achieved adsorption of up to 863.8 milligrams of tetracycline per gram of material and up to 321.3 milligrams of diclofenac per gram, a capability the authors attribute to high surface area, improved hydrophobicity and exceptionally low density. Wood-derived biochar removed up to 397.2 milligrams of the antibiotic sulfamethoxazole per gram, and wood-derived activated carbon removed up to 714.2 milligrams of amoxicillin per gram. Functionalised wood, where the internal surface chemistry is deliberately modified, reached 305.9 milligrams per gram for tetracycline and 350.0 for diclofenac, while wood composites recorded uptakes of 106.4 milligrams per gram for diclofenac and 310.7 for oxytetracycline hydrochloride. These figures place wood-derived materials on par with, and in several cases well ahead of, conventional activated carbons and synthetic adsorbents.

The chemistry behind the sponges is a lesson in elegant simplicity. Wood is first delignified, using enzymes, acids, alkalis, ionic liquids or organic solvents to strip out lignin and hemicellulose, leaving behind a cellulose skeleton with porosity exceeding 96 percent. The removal of lignin opens nanochannels between the fibres, preserving the wood’s intrinsic three-dimensional pore architecture while dramatically enhancing fluid transport. When balsa wood is treated with sulphite and then hydrogen peroxide, the thin cell walls break down entirely, and freeze-drying under ice templating assembles the remnants into a lamellar structure of stacked, interconnected arched layers with a density of just 15 milligrams per cubic centimetre. Reinforcing delignified poplar with polyvinyl alcohol yields aerogels that tolerate 40 percent reversible compression, while chemical vapour deposition of silanes transforms the same scaffold into a superhydrophobic, oleophilic matrix with a water contact angle of 151 degrees.

Biochar follows a different route. Biomass is pyrolysed at 400 to 800 degrees Celsius in an oxygen-depleted environment, releasing volatiles and leaving a solid aromatic carbon rich in adsorption sites. The temperature and feedstock govern the outcome: biochar produced at 600 degrees Celsius reaches 90 to 91 percent carbon content with a yield of roughly 30 percent, while pyrolysis at 800 to 1,000 degrees Celsius pushes carbon content to 94 to 96 percent at a cost in yield. Microwave-assisted pyrolysis and hydrothermal carbonisation offer faster or pre-drying-free alternatives. Post-treatment, such as sulphuric acid oxidation to introduce acidic functional groups or sodium hydroxide washing to increase surface area by 21 to 82 percent, further tailors the material for specific drug molecules.

Activated carbon production adds a second thermal step, activation, which refines the pore network. The review highlights how chemical activation with potassium hydroxide can lift the surface area of wood char from 27.3 to 1,194.4 square metres per gram, far exceeding what steam or carbon dioxide activation achieves on the same feedstock. In one study, dual physicochemical activation of acacia wood carbon using potassium hydroxide followed by microwave-assisted carbon dioxide gasification raised the mesopore surface area from 268.40 to 689.77 square metres per gram and carbon content from 20.92 to 78.60 percent. These numbers matter directly for pharmaceutical capture, since π–π stacking interactions between aromatic drug rings and graphitic carbon domains, along with pore filling, depend on accessible high-energy surfaces.

The review also documents composite strategies that push wood beyond simple carbon. Growing zeolitic imidazolate framework-67 crystals on wood surfaces and carbonising the result produces magnetic, mesoporous composites with saturation magnetisation up to 351.3 electromagnetic units per gram, allowing the spent adsorbent to be retrieved with a magnet. A MXene/wood composite built by impregnating and hot-pressing delignified balsa achieved a tensile strength of 68.1 megapascals, an electrical conductivity of 1,858 Siemens per metre and electromagnetic interference shielding of 32.7 decibels at a thickness of just 0.38 millimetres. Molecularly imprinted basswood membranes embedded with UiO-66 metal–organic frameworks selectively rebound ibuprofen at 120.6 milligrams per gram with separation coefficients above 6.0, thanks to imprinting cavities that match the drug’s shape and hydrogen-bonding pattern.

Mechanistically, the adsorption of pharmaceuticals onto wood-derived materials follows a recognisable set of interactions. Most studies report chemisorption-driven uptake best described by pseudo-second-order kinetics and Langmuir isotherms, indicating monolayer coverage on well-defined binding sites. Tetracycline adsorbs onto citric acid-modified wood most efficiently at pH 5, driven by hydrogen bonding between the wood’s carboxylic hydroxyl groups and the drug’s amide carbonyls, while at neutral pH dipole–dipole interactions between carboxylate groups and protonated dimethylamino groups dominate. Ciprofloxacin favours acidic conditions, where protonated drug molecules engage electrostatically with biochar surfaces, and diclofenac removal is often governed by π–π electron–donor–acceptor interactions, hydrophobic partitioning and pore filling. Perhaps most compelling is a β-cyclodextrin-grafted wood filter, whose interconnected three-dimensional network of microchannels, pits and micropores removed more than 97.5 percent of diclofenac, propranolol, amitriptyline, chlortetracycline and levofloxacin within 90 seconds.

The comparative analysis in the review also reveals that no single wood form wins universally. For tetracycline, the ranking is wood sponges, then functionalised wood, activated carbon, composites and biochar. For diclofenac, activated carbon leads at 490.4 milligrams per gram, followed by biochar, functionalised wood, sponges and composites. For paracetamol, activated carbon again dominates. The pattern reflects a trade-off between surface area, porosity, hydrophobicity and functional group density, and it underscores the authors’ central message: matching the adsorbent architecture to the molecular structure of the target contaminant is essential for optimal performance.

Crucially, the authors are candid about the gap between laboratory promise and industrial deployment. Most studies test concentrations of 5 to 150 milligrams per litre, vastly higher than the microgram-per-litre levels found in real effluents, potentially overestimating practical capacity. Real wastewater carries organic matter, inorganic salts and microorganisms that can foul adsorbent beds, and microbial growth inside wood can degrade flow and performance. Regeneration and safe disposal of spent biochar and activated carbon remain largely unexplored, and some functionalisation routes employ toxic reagents and energy-intensive processes. The reviewers call for green chemistry approaches, life cycle assessments, cost analyses and the use of demolition wood waste and forestry side streams such as sawdust and bark to keep the entire supply chain sustainable.

The broader implications are considerable. Adsorption is already the preferred pharmaceutical-removal technology for its simplicity, reusability and low by-product generation, and wood-derived adsorbents offer a carbon-neutral, scalable route to implementing it at scale. With global initiatives pushing water treatment toward sustainability, the Oulu review positions waste wood not as an environmental burden but as a high-performance platform, a forest product reborn as a water purifier, capable of pulling persistent antibiotics, anti-inflammatories and psychotropic drugs out of the streams that carry them into ecosystems and drinking water supplies.

Graphene oxide, with its exceptional surface area and unique chemical properties, has emerged as a potent material in environmental applications. Its ability to interact with various molecules makes it an ideal candidate for adsorption purposes. The integration of iron oxide nanoparticles, specifically Fe₃O₄, further enhances the adsorbent’s effectiveness, providing magnetic properties that facilitate easy recovery after use. Utilizing a combination of these materials, the research team developed a hybrid adsorbent that maximizes lead removal efficiency while simultaneously allowing for its regeneration and reuse.

The electrochemical synthesis process employed by the researchers represents a leap forward in the fabrication of composite materials. This innovative method not only promotes the formation of the desired nanoparticles but also ensures their uniform distribution throughout the graphene oxide matrix. The application of electrochemical techniques allows for precise control over particle size and surface characteristics, which are critical parameters influencing adsorption capacity. This level of control can significantly enhance the adsorbent’s performance in filtering out lead ions from contaminated water.

One of the standout features of the AmGO-TA/Fe₃O₄ nano-adsorbent is its modification with tannic acid. Tannic acid, a naturally occurring polyphenolic compound, is known for its strong binding affinity to metal ions, which significantly aids in the removal process. By functionalizing the graphene oxide with tannic acid, the researchers created a material that enhances lead ion retention through both electrostatic and chemical interactions, making it particularly effective in aqueous environments where lead concentration may fluctuate.

The study emphasizes the importance of sustainability in the design of adsorbents for environmental cleanup. Conventional methods of lead removal often involve costly reagents and processes that generate secondary waste, contributing further to environmental degradation. In contrast, the electrochemical regeneration of AmGO-TA/Fe₃O₄ not only allows for the effective recovery of lead but also restores the adsorbent’s functionality. This regenerative capability means that the same amount of adsorbent can be used multiple times without significant loss of performance, thus reducing overall material consumption and waste output.

Experimental results presented in the study showcase the significant potential of the AmGO-TA/Fe₃O₄ nano-adsorbent. The removal efficiency for lead ions was found to exceed expectations, achieving high adsorption capacities within a short timeframe. The authors detail the mechanism of lead ion interaction, highlighting the roles played by both the physical properties of the adsorbent and the inherent characteristics of lead ions. This dual approach not only broadens the understanding of lead removal mechanisms but also sets the stage for optimizing adsorbent formulations for future applications.

In addition to laboratory testing, Fakhari et al. explored the operational feasibility of deploying this hybrid adsorbent in real-world settings. The potential for application in various water treatment facilities was discussed, alongside considerations for scalability and economic viability. By addressing these practical aspects, the research paves the way for translating laboratory successes into meaningful environmental action.

The implications of this research extend beyond lead removal. The methodologies and findings derived from the development of the AmGO-TA/Fe₃O₄ adsorbent can inform future studies aimed at addressing other environmental contaminants, such as cadmium, arsenic, and even organic pollutants. The adaptability of the synthesis and modification techniques means that similar approaches could be utilized to construct specific adsorbents tailored to target a diverse range of harmful substances.

As global water resources continue to face the threat of contamination, the demand for innovative, affordable, and sustainable remediation technologies will only grow. The findings presented by Fakhari et al. offer a strong case for the expanded use of nano-adsorbents in environmental cleanup efforts. Their success could serve as a catalyst for further research and development in this critical area, making strides toward cleaner and safer freshwater sources.

In summary, the electrochemical synthesis and regeneration of tannic acid-modified graphene oxide-Fe₃O₄ represent a convergence of advanced material science and environmental engineering, resulting in a powerful tool for lead remediation. The collaborative effort showcased in the study underlines the significance of interdisciplinary approaches in tackling complex environmental challenges. With increasing attention to sustainable practices, technologies like AmGO-TA/Fe₃O₄ may herald a new era in water treatment solutions.

As the research community continues to explore the full potential of nanomaterials in environmental applications, the promising results of this study provide a foundation upon which to build. The integration of eco-friendly materials, innovative synthesis methods, and a focus on reusability signals a positive direction for future advancements in the field.

In conclusion, the development of AmGO-TA/Fe₃O₄ not only aligns with global sustainability efforts but also represents a concrete step toward addressing one of the most pressing environmental issues of our time. The innovation encapsulated in this research underscores the importance of continued investment in scientific inquiry aimed at preserving the integrity of our natural resources.

Subject of Research: Lead removal from aqueous media using modified graphene oxide.

Article Title: Electrochemical synthesis and regeneration of tannic acid–modified graphene oxide-Fe₃O₄ (AmGO-TA/Fe₃O₄) as a recyclable and reusable nano-adsorbent for lead removal from aqueous media.

Article References:

Fakhari, N., Derakhshan, A.A., Rostami, A. et al. Electrochemical synthesis and regeneration of tannic acid–modified graphene oxide-Fe₃O₄ (AmGO-TA/Fe₃O₄) as a recyclable and reusable nano-adsorbent for lead removal from aqueous media.
Environ Sci Pollut Res (2025). https://doi.org/10.1007/s11356-025-37081-0

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s11356-025-37081-0

Keywords: Lead removal, graphene oxide, tannic acid, nano-adsorbent, electrochemical synthesis, water treatment.

Beta-blockers, including widely used drugs like atenolol and metoprolol, serve essential roles in managing various cardiovascular conditions. Their therapeutic efficacy, rooted in their chemical stability, poses a significant challenge when considering their environmental impact. Conventional wastewater treatment facilities often fail to adequately eliminate these compounds, leading to their accumulation in waterways. Even trace amounts can induce chronic toxicity, adversely affecting aquatic ecosystems and potentially compromising public water supplies.

The research team investigated FCOPs as a superior alternative to traditional adsorbents used for removing pharmaceuticals from contaminated water. The study, aiming to bridge the gap in current scientific understanding, reveals that these fluorinated polymers exhibit unprecedented adsorption performance for pharmaceuticals. By employing a straightforward, catalyst-free one-pot synthesis method, the team created FCOPs optimized for beta-blocker removal, achieving remarkable results.

In their experimental setup, the FCOPs demonstrated a striking ability to remove beta-blockers from water. The results showcased a removal efficiency of 67.3% for metoprolol and an impressive 70.4% for atenolol within the first minute of exposure. This rapid adsorption is attributed to the unique structural characteristics of the FCOPs, which allow for both monolayer and multilayer adsorption, a behavior not often observed with conventional adsorbents.

The researchers plotted the adsorption performance against beta-blocker concentration and found a sigmoidal curve, indicating that at lower concentrations, adsorption occurs gradually. This behavior aligns with monolayer adsorption, a phenomenon where individual molecules adhere to a surface. However, upon reaching a concentration threshold of 60 mg/L, a sharp increase in adsorption was observed, suggesting a transition to multilayer adsorption. Multilayer adsorption is critical because it signifies the stacking of molecules in multiple layers, thereby enhancing the overall adsorption capacity of the material.

Moreover, the FCOPs retained their effectiveness even in real water samples, which included various ions and organic compounds. This resilience is a significant advantage, as it demonstrates the potential for practical application in complex environmental matrices. The study further delves into the intricate mechanisms through which FCOPs exert their superior adsorption capabilities, with fluorine atoms playing a pivotal role in multiple synergistic interactions.

One key mechanism identified was the strong intermolecular interactions established between the FCOPs and beta-blockers, driven by the unique structural arrangements of the fluorinated materials. Furthermore, the study highlighted the role of electrostatic interactions, particularly the attraction between positively charged beta-blockers and negatively charged FCOP molecules, which aids in fostering effective adsorption. The hydrophobic nature of FCOPs also minimizes their interaction with water, promoting clustering of adsorbed molecules, supporting the multilayer adsorption process.

The implications of this research are profound. As Professor Hwang stated, “Our study presents FCOPs as a promising solution for addressing persistent beta-blockers in water. The insights into their adsorption mechanisms lay the groundwork for the development of next-generation adsorbents.” This innovative approach not only offers the potential for improved water treatment methods but also emphasizes the importance of environmental protection and public health safety.

In conclusion, the integration of FCOPs into advanced wastewater treatment systems could significantly enhance the ability of water utilities to tackle pharmaceutical pollution. Given the increasing prevalence of contaminants like beta-blockers in aquatic environments, finding sustainable solutions is imperative. This research not only highlights the unique properties of fluorinated covalent organic polymers but also sets the stage for future developments in environmental remediation technologies, paving the way for cleaner, safer water sources for generations to come.

The promising capabilities of FCOPs in removing harmful substances from water exemplify the progress being made in environmental science and engineering. As researchers continue to innovate and refine materials for water purification, it becomes increasingly essential to consider the ecological balance and the health of both ecosystems and human populations. The study led by Professor Hwang shines a spotlight on the critical intersection of advanced material science and environmental engineering, offering hope for more effective strategies in battling pharmaceutical contamination in our waters.

This research not only advances scientific understanding but also serves as a clarion call for urgent action in protecting our precious water resources. As we continue to grapple with the implications of persistent pharmaceuticals in the environment, the findings surrounding FCOPs could be instrumental in shaping future water treatment approaches, ensuring a healthier planet for all.

In summary, the study elucidates a groundbreaking approach to fabricating advanced adsorbents that show extraordinary promise for real-world applications. FCOPs exemplify the innovative strategies needed to address complex environmental challenges, pushing the boundaries of material science and paving the way toward sustainable solutions.

Subject of Research: Adsorption of beta-blockers using fluorinated covalent organic polymers (FCOPs)
Article Title: Efficient removal of beta-blockers from water using fluorinated covalent organic polymers: Insights into sigmoidal adsorption behaviour and environmental applications
News Publication Date: 28-Jul-2025
Web References: Environmental Research
References: DOI: 10.1016/j.envres.2025.122439
Image Credits: Professor Yuhoon Hwang from Seoul National University of Science and Technology

Keywords

Environmental engineering; Environmental management; Environmental remediation; Pollution control; Water management; Water treatment; Wastewater treatment; Pharmaceuticals; Water purification.

Earth’s oceans hold approximately 97% of the planet’s water, yet their high salinity renders this bounty undrinkable without treatment. Traditional desalination techniques, such as reverse osmosis and thermal distillation, require vast amounts of electricity or heat, making them costly and environmentally burdensome. Seeking a solution that harnesses renewable energy and offers scalability, scientists led by Xi Shen have developed an aerogel with distinctive microscopic structures that optimize solar vapor generation while maintaining consistent efficiency irrespective of size.

Unlike conventional hydrogels that rely on liquid-filled pores and tend to exhibit squishy, gel-like properties, this aerogel features a rigid architecture composed of solid pores. The researchers crafted a composite paste integrating carbon nanotubes alongside cellulose nanofibers, then employed an additive freeze-printing technique to meticulously deposit successive layers onto a frozen surface. This layered process yields a porous matrix riddled with uniform vertical channels approximately 20 micrometers wide, providing directional pathways for water vapor to escape during evaporation.

One of the formidable issues in scaling up solar-driven desalination materials is a decline in evaporation performance as the material’s size increases. However, the unique design of this aerogel overcomes this obstacle by maintaining size-insensitive vapor diffusion. Experiments using samples ranging from a mere one centimeter square to over eight centimeters confirmed that larger samples did not suffer diminished efficiency, an essential attribute for practical, real-world applications.

The desalination mechanism is elegantly straightforward. Seawater is loaded beneath the aerogel, which is then capped with a curved, transparent plastic cover. Solar radiation heats the upper surface of the material, initiating selective evaporation of water molecules while preventing the passage of salt ions. This process concentrates pure water vapor on the inner surface of the plastic cover, where it condenses and gravitates downward, ultimately collected as potable water in a separate container. This passive, solar-driven system obviates the need for external electrical inputs or mechanical pumps.

Outdoor field tests underscored the practical utility of this technology. After six hours under natural sunlight, the setup yielded approximately three tablespoons of clean water—an impressive proof-of-concept volume for a relatively compact device. The ability to operate entirely on ambient solar energy positions this aerogel as a promising candidate for off-grid desalination solutions, especially in remote or resource-limited regions.

Central to the aerogel’s performance is the synergistic role of its constituent materials. Carbon nanotubes contribute exceptional thermal conductivity, facilitating rapid heating of the evaporative surface, while cellulose nanofibers provide structural integrity alongside hydrophilic channels to draw seawater efficiently. The freeze-printing fabrication process enables precision control over pore size and distribution, a critical factor in optimizing vapor flow dynamics and evaporation rates.

This breakthrough resonates profoundly in the context of global water security. With climate change exacerbating droughts and freshwater scarcity, technologies that tap abundant solar energy for water purification hold immense promise. The scalability of the aerogel, combined with its energy-free operation and straightforward manufacturing techniques, could enable decentralized deployment, empowering communities worldwide to access clean drinking water sustainably.

Prior efforts to harness solar energy for desalination have leveraged hydrogels mimicking natural porous structures such as loofahs, which demonstrated rapid water vapor release upon sunlight exposure. Yet these hydrogels often suffer from mechanical fragility and size-dependent performance. Aerogels, with their solid pore networks, provide enhanced dimensional stability but traditionally face challenges with evaporation efficiency in larger formats. Addressing these limitations, the newly reported aerogel design exemplifies how advanced materials engineering can surmount longstanding barriers.

The research team envisions that future iterations may improve water yield through integrating photothermal coatings or coupling with passive condensation surfaces to maximize vapor capture. Moreover, the additive freeze-printing methodology lends itself to customization for various deployment scenarios, tailoring pore geometries and layer thicknesses to optimize performance under diverse climatic conditions.

In conclusion, the development of this size-insensitive, additive freeze-printed aerogel marks a pivotal advancement toward scalable, low-energy desalination. By translating solar energy directly into potable water without external power inputs, the technology aligns with global sustainability goals and offers a transformative approach to addressing one of humanity’s most pressing environmental challenges. As further studies explore optimization and deployment strategies, this solar-powered sponge may well become a cornerstone in the quest for accessible, clean water worldwide.

Subject of Research: Solar-driven, size-insensitive desalination using 3D-printed aerogels
Article Title: “Size-Insensitive Vapor Diffusion Enabled by Additive Freeze-Printed Aerogels for Scalable Desalination”
News Publication Date: July 2, 2025
Web References: http://pubs.acs.org/doi/abs/10.1021/acsenergylett.5c01233
References: Adapted from ACS Energy Letters 2025, DOI: 10.1021/acsenergylett.5c01233
Image Credits: Adapted from ACS Energy Letters 2025, DOI: 10.1021/acsenergylett.5c01233

Keywords

Chemistry, Water, Desalination, Aerogels, Solar Energy, Nanomaterials, Sustainable Technology