Every year, new compounds contained in consumer products, such as detergents, paints, products for personal hygiene, and drugs for human and veterinary use, are identified in wastewater and are added to the list of molecules that need monitoring. These compounds are indicated with the term emerging contaminants (or Contaminants of Emerging Concern, CECs) since they are potentially dangerous for the environment and human health. To date, among the most widely used methodologies for the removal of CECs from the aquatic environment, adsorption processes play a role of primary importance, as they have proven to be characterized by high removal efficiency, low operating and management costs, and an absence of undesirable by-products. In this paper, the adsorption of ibuprofen (IBU), a nonsteroidal anti-inflammatory drug widely used for treating inflammation or pain, was performed for the first time using two different types of geopolymer-based materials, i.e., a metakaolin-based (GMK) and an organic–inorganic hybrid (GMK-S) geopolymer. The proposed adsorbing matrices are characterized by a low environmental footprint and have been easily obtained as powders or as highly porous filters by direct foaming operated directly into the adsorption column. Preliminary results demonstrated that these materials can be effectively used for the removal of ibuprofen from contaminated water (showing a concentration decrease of IBU up to about 29% in batch, while an IBU removal percentage of about 90% has been reached in continuous), thus suggesting their potential practical application.

Phenol is widely used in industry. Due to its high stability and toxicity, it represents a threat to the environment and human health. In this study, a kinetic investigation of phenol heterogeneous photodegradation was conducted using commercial Aeroxide P-25, performing experiments in a wide range of conditions. In detail, a negligible adsorption effect was detected. An activation energy of Ea = 14.3 ± 0.5 kJ mol⁻¹ was measured, and the catalyst loading effect indicated an optimal condition due to the shield of the catalyst particles to the UV irradiation. The catalyst was most active at pH = 7 and it was stable for 25 h of reaction time; thus, it will be worth to investigate its application in flow.

Metakaolin-based geopolymers with different molar ratios of Si/Al were synthesized and utilized as an efficient adsorbent for the removal of methylene blue (MB) as a model cationic dye from aqueous solution. Various analytical techniques were employed to characterize the synthesized geopolymers. The influence of the main operation conditions on the adsorption kinetics of MB onto the geopolymer was examined under various operating conditions. Results showed a significant maximum MB adsorption capacity at the temperature of 30 °C for all four types of geopolymers studied (designated as A, B, C, and D) up to 35.3, 23.6, 25.5, and 19.0 mg g⁻¹, respectively. The corresponding order of Si/Al ratio was A < C < B < D. Adsorption kinetics was so fast and reached equilibrium in 10 min, and the experimental results were described using the adsorption dynamic intraparticle model (ADIM). The equilibrium data for MB removal was in agreement with the Langmuir isotherm.

Ketoprofen is a non-biodegradable drug and is not removed by conventional treatments. The need to remove pharmaceutical compounds from water and wastewater has aroused considerable interest in advanced oxidation processes (AOP), whose effectiveness depends on the generation of reactive free radicals capable of oxidizing and decomposing numerous compounds. Heterogeneous photocatalysis is an efficient method if an active semiconductor is used. In this work, the photodegradation reaction of ketoprofen promoted by TiO₂ was studied, analyzing the kinetics obtained by changing variables such as temperature, initial concentration, and quantity of photocatalyst. It was determined that the mechanism is of the Langmuir–Hinshelwood type and that the system is operating in the kinetic regime, while tests at different temperatures have shown that the adsorption of ketoprofen and byproducts are both exothermic. Experimental data were interpreted with reliable models that allow to retrieve quantitatively the kinetic and thermodynamic parameters.