Pretreated waste Streptomyces fradiae biomass was used as biosorbent to remove tetracycline (TC) from model aqueous solutions. The biosorption study was conducted in a batch system to evaluate the impact of initial pH, biosorbent dosage, initial TC concentration and contact time. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm equilibrium studies. Langmuir and Freundlich models fitted the equilibrium data better than the D–R model. The monolayer biosorption capacity of the pretreated biomass for TC was 38.61 mg g⁻¹. The experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second order kinetics models. The results showed that the TC biosorption process followed well pseudo-second-order kinetics.

The removal of pharmaceuticals from aqueous environments has become a critical ecological challenge. Biosorption has emerged as a promising and cost-effective solution for pharmaceutical removal. This review examines the potential of microbial and algal-derived biosorbents, including fungi, bacteria, and algae, in the biosorption of pharmaceuticals from water. The removal efficiency of various types of biosorbents is discussed in relation to the chemical structure and functional groups presented on the biosorbent surfaces at various process parameters, such as pH, contact time, biosorbent dosage, and initial pharmaceutical concentration. Additionally, the benefits of chemical and physical modifications, immobilization techniques, and the reusability of biosorbents are highlighted. The major goal of the present review is not just to gather and discuss information about possible mechanisms of biosorption, which to some extent are still speculative, and to explain the effect of process parameters on the removal but also to highlight the advantages and disadvantages of various types of microbial/algal biosorbents and to ease the selection of proper biosorbents for pharmaceuticals removal. In this way, the review will benefit and induce more technological studies in the field of biosorption.

Four azo dyes known to form anionic complexes with V(V) were investigated as potential liquid–liquid extraction–spectrophotometric reagents for the antihistamine medication hydroxyzine hydrochloride (HZH). A stable ion-association complex suitable for analytical purposes was obtained with 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR). The molar absorption coefficient, limit of detection, linear working range, and relative standard deviation in the analysis of real pharmaceutical samples (tablets and syrup) were 3.50 × 10⁴ L mol⁻¹ cm⁻¹, 0.13 μg mL⁻¹, 0.43–12.2 μg mL⁻¹, and ≤2.7%, respectively. After elucidating the molar ratio in the extracted ion-association complex (HZH:V = 1:1), the ground-state equilibrium geometries of the two constituent ions—HZH⁺ and [VO₂(HTAR)]⁻—were optimized at the B3LYP level of theory using 6-311++G** basis functions. The cation and anion were then paired in four different ways to find the most likely structure of the extracted species. In the lowest-energy structure, the VO₂ group interacts predominantly with the heterochain of the cation. A hydrogen bond is present (V–O···H–O; 1.714 Å) involving the terminal oxygen of this chain.

This study explores the use of the waste-pretreated biomass of the macro-fungus Ganoderma resinaceum as a biosorbent for removing ciprofloxacin from aqueous solutions. Batch experiments were conducted to evaluate the biosorption performance of G. resinaceum under varying conditions. Key operational parameters—including pH, biosorbent dosage, contact time, and initial ciprofloxacin concentration—were systematically assessed. Equilibrium was reached within 120 min. Equilibrium data were fitted to both Freundlich and Langmuir isotherm models, with the Langmuir model providing a better fit. Under optimal conditions (initial pH of 7.0, 120-min contact time, 1 g/L biosorbent dosage, and ciprofloxacin concentrations ranging from 4 to 20 mg/L), the maximum biosorption capacity was determined to be 18.4 mg/g. Kinetic analysis revealed that the biosorption process followed a pseudo-second-order model. Furthermore, the biomass was characterized before and after biosorption using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The FT-IR analysis of G. resinaceum biomass revealed the presence of hydroxyl, amino, and carbonyl functional groups, which play a crucial role in the binding and biosorption of ciprofloxacin molecules.