Adsorptive Removal of Pharmaceutical Contaminants from Aqueous Solutions

The pervasive presence of pharmaceutical residues in water bodies poses a mounting risk to ecosystems and human health, as conventional treatment plants often fail to eliminate trace levels of antibiotics, analgesics and endocrine‐active compounds. Adsorptive removal exploits the affinity of these pollutants for solid surfaces, offering a cost-effective and adaptable tertiary treatment. Recent advances focus on tailored adsorbents with high surface areas, tunable surface chemistry and magnetic recoverability to capture diverse molecular structures. Materials such as metal–organic frameworks (MOFs), functionalised polymers, bio-derived carbons and clay minerals have been engineered to enhance uptake via electrostatic attraction, hydrogen bonding, π–π electron donor–acceptor interactions and hydrophobic partitioning. Beyond batch experiments, coupling adsorption units with membrane systems, fixed-bed columns and magnetic separation modules demonstrates practical scalability. Reusability and regeneration remain critical, with studies reporting minimal loss of capacity over multiple cycles. As research converges on green synthesis routes and hybrid treatment trains, adsorptive technologies are poised to deliver resilient solutions for safeguarding water supplies against emerging pharmaceutical contaminants.

Research from Nature Portfolio

One study introduced a three-dimensional porous graphene hydrogel produced by a simple hydrothermal reduction. The material demonstrated exceptionally high adsorption capacity for ciprofloxacin—exceeding 200 mg per gram—through a synergistic combination of π–π interactions, hydrogen bonding and hydrophobic effects. The high water content retained within the hydrogel network accelerated diffusion and enhanced removal efficiency in minutes. Importantly, size reduction of the hydrogel granules improved kinetics without compromising capacity, suggesting adaptability to continuous flow systems.

Another investigation examined the influence of natural organic matter, specifically humic acid, on the performance of magnetic multifunctional resins. Under acidic conditions, adsorbed humic fragments formed additional adsorption sites, boosting antibiotic uptake. In contrast, at alkaline pH humic acid competed for ion‐exchange sites and reduced removal. This work underscores the need to account for background organic matter when designing adsorptive treatments for real water matrices.

Adsorptive Removal of Pharmaceutical Contaminants from Aqueous Solutions publication trend

The graph below shows the total number of articles in adsorptive removal of pharmaceutical contaminants from aqueous solutions across all publications each year (not limited to Nature Index journals).

Technical terms

Adsorption capacity: The maximum mass of contaminant a unit mass of adsorbent can capture under defined conditions.

Metal–organic framework (MOF): A porous crystalline material composed of metal nodes linked by organic ligands, valued for high surface area and tunable chemistry.

π–π electron donor–acceptor interaction: Non-covalent attraction between aromatic rings of adsorbent and pollutant molecules, enhancing binding of heterocyclic drugs.

Point of zero charge (pHpzc): The pH at which an adsorbent’s surface carries no net electric charge, influencing electrostatic interactions.

Isotherm model: Mathematical description of how adsorbates distribute between liquid phase and adsorbent at equilibrium, often represented by Langmuir or Freundlich equations.

Pseudo‐second‐order kinetics: A rate model assuming adsorption rate is proportional to the square of the number of available sites, frequently observed in chemisorption-controlled processes.

References

1. Water-enhanced Removal of Ciprofloxacin from Water by Porous Graphene Hydrogel. Scientific Reports (2015).
2. Effect of humic acid on ciprofloxacin removal by magnetic multifunctional resins. Scientific Reports (2016).
3. Fabrication of porous beta-cyclodextrin functionalized PVDF/Fe–MOF mixed matrix membrane for enhanced ciprofloxacin removal. npj Clean Water (2024).
4. Novel Magnetite Nanocomposites (Fe3O4/C) for Efficient Immobilization of Ciprofloxacin from Aqueous Solutions through Adsorption Pretreatment and Membrane Processes. Water (2022).
5. Characterization of activated bentonite clay mineral and the mechanisms underlying its sorption for ciprofloxacin from aqueous solution. Environmental Science and Pollution Research (2020).