The use of enterosorbents—materials which can be administered orally and eliminate toxic substances from the gastrointestinal tract (GIT) by sorption—offers an attractive complementary protection of humans against acute and chronic poisoning. In this study, we report the results of developing a microgranulated binary biomedical preparation for oral use. It was designed with a core-shell structure based on pectin with low degree of esterification as the core, and nanoporous activated carbon produced from rice husk, AC-RH, as the shell, designated as AC-RH@pectin. The adsorption properties of the synthesized materials were studied in aqueous solutions for the removal of lead (II) nitrate as a representative of toxic polyvalent metals and sodium diclofenac as an example of a medicinal drug. The composite enterosorbent demonstrated high adsorption capacity for both adsorbates studied. Adsorption kinetics of lead and diclofenac adsorption by AC-RH, pectin, and AC-RH@pectin, fitted well a pseudo-second-order model. According to the Langmuir adsorption isotherm model, the best fitted isotherm model, the maximum adsorption capacity, q_max, of AC-RH@pectin for diclofenac and for lead (II) was 130.9 mg/g and 227.8 mg/g, respectively. Although q_max of AC-RH for diclofenac, 537.6 mg/g, and q_max of pectin for lead (II), 245.7 mg/g, were higher, the maximum adsorption capacity of AC-RH for lead (II), 52.7 mg/g, was much lower than that of the composite AC-RH@pectin and the adsorption capacity of pectin for diclofenac was negligible. Therefore, the composite material AC-RH@pectin demonstrated substantial efficiency of removing both species which potentially defines it as a more universal enterosorbent suitable for treating poisoning caused by substances of different chemical nature.

This study investigates the potential of biochar derived from various biomass sources: apricot kernel (AK), pine sawdust (PS), rice husk (RH), wheat straw (WS), and reed stem (RS) to enhance the yield, nutritional quality, and environmental sustainability of parsley crops. Comprehensive characterization through SEM, EDAX, nitrogen adsorption–desorption isotherms, and FTIR analyses identified AK biochar as the most suitable for further enrichment due to its superior specific surface area (512.3 m²/g) and iodine number (51.23 mg/g). EDAX analysis revealed that AK biochar exhibited the highest carbon content (92.1%), while RH biochar contained the highest silicon content (46%), indicating different potential applications. FTIR analysis identified key functional groups, such as carbonyl (1740 cm⁻¹) and hydroxyl (3430 cm⁻¹) groups, which contribute to the biochar’s reactivity and potential effectiveness in various applications. The effects of selenium (Na₂SeO₄), iodine (KI), their combination (Na₂SeO₄ + KI), and BISF (biochar‐enriched iodine and selenium fertilizer) on parsley growth, antioxidant properties, and nutrient accumulation were evaluated. The results demonstrated that joint applications of iodide and selenate led to a 3.1‐fold increase in iodine content (up to 16.8 mg/kg d.w.) and a 1.2‐fold increase in selenium accumulation (up to 2482.1 μg/kg d.w.) in parsley compared to separate treatments. Additionally, BISF treatment significantly improved key biometric parameters, with leaf weight increasing by 1.6 times (up to 326.5 g) compared to the control, and antioxidant content—ascorbic acid, polyphenols, and antioxidant activity—showing increases of 1.56, 1.27, and 1.50 times, respectively. This study underscores the effectiveness of selenium‐ and iodine‐enriched biochar in enhancing parsley crop yield and nutritional quality while also demonstrating the multifunctional role of biochar in environmental remediation.

The sustainable operation of hydroponic systems depends on maintaining the chemical stability of circulating nutrient solutions and preventing the accumulation of toxic compounds. The accumulation of phytotoxic ammonium, heavy metals, and organic metabolites in recirculating nutrient solutions remains one of the key challenges limiting the efficiency, sustainability, and scalability of hydroponic cultivation. This review provides a comprehensive comparative analysis of zeolites, activated carbons (ACs), and their functionalized and composite forms as key sorbents for nutrient management, contaminant removal, and environmental safety in hydroponic cultivation. Natural zeolites, with their well-defined crystalline structure and high ion-exchange selectivity toward ammonium and heavy metal cations, enable effective NH₄⁺/K⁺ balance regulation and phytotoxicity mitigation. ACs, characterized by high specific surface area and tunable surface chemistry, complement zeolites by offering extensive adsorption capacity for organic compounds, root exudates, and pesticide residues, thereby extending the operational lifespan of nutrient solutions and improving overall system performance. Further advancements include the integration of zeolites and ACs with two-dimensional (graphene, g-C₃N₄) and three-dimensional (MOF, COF) frameworks, yielding multifunctional materials that combine adsorption, ion exchange, photocatalysis, and nutrient regulation. Transition-metal modification, particularly with Fe, Mn, Cu, Ni, and Co, introduces redox-active centers that enhance sorption, catalysis, and phosphate stabilization. The comparative synthesis reveals that the combined application of zeolite- and carbon-based composites offers a synergistic strategy for developing adaptive and low-waste hydroponic systems. From a techno-economic and environmental standpoint, the judicious application of these materials paves the way for more resilient, efficient, and circular hydroponic systems, reducing fertilizer and water consumption, lowering contaminant discharge, and enhancing food security. This systematic review was conducted according to the PRISMA 2020 guidelines. Relevant studies were identified through Scopus, Web of Science, and Google Scholar databases using specific inclusion and exclusion criteria.

The paper demonstrates that activated carbon surface area, micropore volume, and toal pore volume can be estimated using multiple regression with iodine and methylene blue numbers. The method was developed by studying activated carbon samples made from rice husk precursors. A justification for the selection criteria is given based on the physicochemical characteristics of the adsorbent. Activated carbon was studied to systematically evaluate the influence of pore structure and surface chemistry. A technique has been developed to estimate the surface area, micropore volume and total pore volume of activated carbon samples by multiple regression of iodine number and methylene blue number. Among a series of KKK samples obtained by activating rice husks with phosphoric acid at different temperatures, it was studied that the samples (KKKR-400 and KKK-R-500), activated at a temperature of 400-500^oC, have a high specific surface area. area and iodine number. The more oxygen in the initial and final products, the higher the ratio of the specific surface area and iodine number of ACM: it was found that the specific surface area (1690 m²/g) and iodine number (1150 mg/g) of the samples obtained by activation with phosphoric acid at a temperature of 500^°C were higher.

The article describes the synthesis of an activated carbon-carbon/ash composite based on carbonized rice husk (CRH) and Ca-lignosulfonate. The obtained adsorbents were characterized by modern physicochemical research methods: scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS analysis), X-ray photoelectron spectroscopy (XPS), and low-temperature nitrogen adsorption. It was established that despite the presence of residual mineral impurities in an amount of about 15 wt. %, the synthesized CRH-lignosulf@850 composite exhibits a high specific surface area and a well-developed pore volume. These impurities are represented by the phases CaSiO3, MgSiO3, CaSO4 and SiO2, which proved to be resistant to alkaline leaching. The morphology of the obtained composites features a well-developed structure with both micro- and mesoporosity. According to calculations based on the Quenched solid density functional theory (QSDFT), the specific surface area of the obtained СRH-lignosulf@850 sample is 1144 m²/g, and the total pore volume is 0.947 cm³/g. Studies of methylene blue (MB) sorption under static conditions showed that the CRH-lignosulf@850 composite demonstrates high adsorption performance. According to the adsorption isotherms, the Toth model effectively describe the process, with the maximum sorption capacity of the material reaching 283.4 mg/g. The results obtained indicate the potential for using CRH-lignosulf@850 blocks to capture toxic compounds in emissions from enterprises producing organic products.