The increasing presence of pollutants, including pharmaceuticals and pesticides, in water resources necessitates the development of effective remediation technologies. Zeolites are promising agents for pollutant removal due to their high surface area, ion-exchange capacity, natural abundance, and diverse tailorable porous structures. This review focuses on the efficient application of modified zeolites and mesoporous materials as photocatalysts and adsorbents for removing contaminants from water bodies. The adsorption and photodegradation of pesticides and selected non-steroidal anti-inflammatory drugs and antibiotics on various zeolites reveal optimal adsorption and degradation conditions for each pollutant. In most reported studies, higher SiO₂/Al₂O₃ ratio zeolites exhibited improved adsorption, and thus photodegradation activities, due to increased hydrophobicity and lower negative charge. For example, SBA-15 demonstrated high efficiency in removing diclofenac, ibuprofen, and ketoprofen from water in acidic conditions. Metal doped into the zeolite framework was found to be a very active catalyst for the photodegradation of organic pollutants, including pesticides, pharmaceuticals, and industrial wastes. It is shown that the photocatalytic activity depends on the zeolite-type, metal dopant, metal content, zeolite pore structure, and the energy of the irradiation source. Faujasite-type Y zeolites combined with ozone achieved up to 95% micropollutant degradation. Bentonite modified with cellulosic biopolymers effectively removed pesticides such as atrazine and chlorpyrifos, while titanium and/or silver-doped zeolites showed strong catalytic activity in degrading carbamates, highlighting their environmental application potential.

Bis(2,2′-bipyridine) complexes of ruthenium(II) with 2-, 3-, and 4-acetylpyridine derivatives were synthesized and structurally characterized. The effect of changing the location of the pyridine's acetyl substituent was studied experimentally and theoretically to clarify the effect of substituent position on the chemical behavior and photochemical properties of the complex. The substituent position on the heterocyclic-pyridine was found to strongly affect the chemical and photochemical properties of the complex. Variation of the position of the substituent, and thus ligand modification brought by as a consequence of this variation, offers possibilities to design complexes of desired structural and photochemical properties.

Four N-donors (PHDA, ATPH, APHO, and MTAN) containing NH₂ were used to extract Hg(II), Cd(II), and Pb(II). Their extraction capacity was determined by measurement of percentage extraction. The chelates extract these metals differently: for example, efficiency of ATPH was the highest for Hg(II) compared to PHDA, APHO, and MTAN. The extraction efficiency was found to depend on: donor atom hardness, chelate total hardness, metal: chelate mole ratio and substituent’s electronic effects. Among all, total hardness and chelate stability are key factors and molecule of small (E_HOMO – E_LUMO) is more reactive, where extraction efficiency increases as molecular stability decreases.