Fly ash, produced during coal combustion for energy making, which is recognized as an industrial by-product, could lead to environmental health hazards. Subsequently, fly ash found that an exceptional adsorption performance for the removal of various toxic pollutants, the adsorption capacity of fly ash might be altered by introducing physical/chemical stimulation. Successfully converting fly ash into zeolites not only recovers their disposal difficulties but also transforms unwanted materials into merchandisable products for various industrial applications. Here we fabricated that, converting fly ash into zeolite and then modifying it with aminopropyl imidazole (ionic liquid), the imidazolium-based zeolite will be used as a template for loading Fe3O4 NPs. The formation of Fe3O4 NPs decorated zeolites is incorporated with polymeric materials [including polystyrene sulphonate (PSS), polyvinyl alcohol (PVA) and chitosan], producing to magnetic film (named Fe3O4 NPs@zeolite film). The fabricated magnetic film exhibits excellent functionality and durability for the sorption of chromium, selenium and organic dyes such as Congo red, RhB. These toxic contaminates were electrostatically bonded through adsorbent due to their protonation of below the pHzpc 7.0 with surface functional groups from imidazolium cationic moiety (R-N+), amino groups derived chitosan (-N, -NH and -NH2), and hydroxyl groups (Fe-OH), electrostatically bind with anionic selenium species are [(SeO32-, Se(IV)), and (SeO42- Se(VI)], chromium species HCrO4-, Cr2O72- and CrO42- the maximum removal performance were achieved in a wide pH range are highly suitable for practical application.

In this study, we report the optimized and fully controlled coal-fly-ash based Na-P1 (GIS) zeolite modification by employing biodegradable biosurfactant molecule - cocamidopropyl betaine (CAPB) aimed at effective aqueous U removal. The zeolite’s surface decoration renders three composites with varying amounts of CAPB molecules, named Na-P1@CAPB, with 0.44, 0.88, and 1.54 ECEC coverage. Batch U adsorption isotherms experiments revealed extremely high U adsorption capacity (qmax = 137.37 mg U/g) following the partitioning mechanism, thus preferential hydrophobic interactions between CAPB molecules and uranyl ions present in the solution, as well as ion-exchange with Na+ present in the GIS zeolite framework. Comprehensive spectroscopic studies after U adsorption, including FT-IR, XPS, and XAFS techniques, revealed a hexavalent oxidation state of U as well as no secondary release of the CAPB molecule to the solution, confirming excellent stability of the composite during the adsorption process. The FT of the EXAFS signals for zeolite compared to the reference U salt, show the changes in the interatomic distances of the engineered materials after U removal, implying a significant impact of the O and N, heteroatoms along with hydrocarbon tail chain present in the CAPB molecule on U binding mechanism. The presented research outcomes showcase the easy, scalable, chemically optimized, and environmentally friendly synthesis of advanced U scavenger, which is probably the most effective zeolitic material worldwide regarding U extraction performance. Moreover, the real-life U-bearing wastewaters from the vicinity of the Pribram deposit (Czech Republic) have been effectively purified by applying NaP1@CAPB composite, satisfying WHO guidelines.

Waste fly ash, with both low (with the addition of vermiculite) and high contents of unburned coal, were subjected to hydrothermal syntheses aiming to obtain zeolite composite materials—zeolite + vermiculite (NaX–Ver) and zeolite + unburned carbon (NaX–C). The composites were compared with parent zeolite obtained from waste fly ash with a low content of unburned carbon (NaX–FA). In this study, the physicochemical characteristics of the obtained materials were evaluated. The potential application of the investigated zeolites for the adsorption of ammonium ions from aqueous solutions was determined. Composite NaX–Ver and parent zeolite NaX–FA were characterized by comparable adsorption capacities toward ammonium ions of 38.46 and 40.00 mg (NH4+) g−1, respectively. The nearly 2-fold lower adsorption capacity of composite NaX–C (21.05 mg (NH4+) g−1) was probably a result of the lower availability of ion exchange sites within the material. Adsorbents were also regenerated using 1 M NaCl solution at a pH of 10 and subjected to 3 cycles of adsorption–desorption experiments, which proved only a small reduction in adsorption properties. This study follows the current trend of waste utilization (fly ash) and the removal of pollutants from aqueous solutions with respect to their reuse, which remains in line with the goals of the circular economy.

Heavy metal toxicity is highly demanding and challenging to clean up the pollutants. To recover the issues mentioned above, we propose a hydrothermal synthesis of zeolite (NaX-UP). Further surface modification by poly-ethylenimine (PEI) could turn to be amine-modified zeolite nanosheets (zeolite NSs) possessed plenty of hydroxyl and amino groups (Al-O, Si-O-Si, Si-OH and NH2) on their surface, decorated with magnetic nanoparticles (Fe3O4 NPs), that are enabled to bridge with inter and intramolecular hydrogen bonding an additionally electrostatic interaction might be a significant role. Further, this can be converted into magnetic bead crosslinking with sodium alginate immersed in an excess calcium chloride solution. The-as formed Fe3O4 NPs decorated amine modified zeolite alginate bead denoted to be (Fe3O4 NPs decorated @PEI-zeolite NSs alginate bead) upholding a significant advantage would aim to clean up the anionic pollutants are [As(V) & V(V)] from an aqueous solution.

Water contamination caused by anthropogenic, and unforecasted release of BTEX (benzene, toluene, ethylbenzene and xylene) compounds threatens the quality and integrity of aquatic ecosystems. BTEX sorption with novel materials characterized by increased hydrophobicity and stability has been proposed to overcome such contamination. This study aimed to investigate the whole array of hydrothermally synthesized zeolitic materials exhibiting different properties, as well as zeolite/carbon and zeolite/vermiculite composites, to analyse their potential in removing aqueous BTEX. Various parameters and experimental conditions, including the type of volatile organic compounds (VOCs), initial concentration, BTEX coexistence, and increased solution salinity, were studied to verify the applicability of the derived materials. The adsorption capacity of the materials and their governing removal mechanisms were additionally elucidated. The primary removal mechanism involved partitioning on unburned carbon residues, which was observed in zeolite/carbon composites showing the highest BTEX removal efficiency. NaA-zeolite/carbon composite was the most effective in removal of BTEX, with the removal capacity of 15.36 mg/g towards p-xylene. Moreover, the increased salinity of the BTEX solution affects adsorption performance for polar adsorbates, irrespectively of the applied zeolite/carbon composite. Fly-ash (FA) and high-carbon fly-ash (HCFA) were successfully valorised into products with better textural features. These products may effectively tackle organic water pollution caused by VOCs under near-real-life conditions.

Volatile organic compounds (VOCs) are harmful contaminants that are emitted into the environment as a result of various commercial, industrial, and domestic practices. Their presence in water leads to pollution and poses a huge threat to the ecological environment and human health. They are typically released into the environment through a spill or inappropriate disposal which allows the chemicals to get absorbed into the ground or enter the sewage system. Thus far, several treatment methods have been developed to remove VOCs from water, including steam stripping or air stripping, ion exchange, filtration, adsorption, and application of various types of sorbents. Due to their cost-effectiveness and efficiency, the use of mesoporous materials, especially those synthesized from coal fly ash (FA), is recognized as the most promising strategy for slowing down the impact of VOCs. This study is believed to be the first to assess the advances made in improving the adsorption of VOCs by different functional mesoporous materials (FA, zeolites, mesoporous silica, metal organic frameworks). The impact associated with the properties of these materials is carefully summarized in this paper, in regard to their solid-state characteristics, material synthesis method, and surface modification. In addition, their chemical and physical interactions in solution, the reaction kinetics, and the influence of temperature and pH are described in detail. The aim of this work was to compare the sorption properties of the materials synthesized from FA with more complex mesoporous materials. This overview provides a comprehensive understanding of VOC removal from water systems using various functional materials, as well as helps in identifying the materials that may play a key role in the future.

Surfactant-modified minerals are widely used for the sorption of anionic forms of contaminants, including chromium compounds. The growing emphasis on environmental protection and economic aspects leads to increased interest in the possibility of regeneration and reuse of the sorbent. The paper attempts to determine the regeneration potential of the synthesized organo-zeolites after the sorption of Cr(III) and Cr(VI) by conducting cycles of sorption-desorption of chromium using desorbing solutions. Hexadecyltrimethylammonium bromide (HDTMA) was used to modify the synthetic zeolite Na-P1 and Na-X derived from fly-ash, obtaining a surface coverage of 1.0 external cation-exchange capacity (ECEC). Several desorbing solutions were used, such as KOH, KNO 3 , Na 2 CO 3 , K 2 HPO 4 , NaHCO 3 , NaCl, CH 3 COONa, K 2 SO 4 , Na 2 S 2 O 4 . During the five sorption-desorption cycles, the ability to Cr(III) and Cr(VI) of used solutions desorption decreased with the simultaneous activation of the sorbent, increasing its sorption capacity. The solutions showed similar properties and have different abilities to chromium desorption and the same of the sorbent regeneration potential. The reacted organo-zeolites were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The conducted experiments proved the possibility of effective regeneration of HDTMA-modified zeolites using desorbing solutions. Activation of the sorbent surface may be caused by the development of the sorbent surface under the influence of aggressive alkaline desorbing

The de-icing of roads and streets in the winter season is a necessity in many European countries, where the mean day temperature drops below 0 degrees C for long periods. Among the many chemicals used for winter road maintenance, the most popular in Poland is sodium chloride in various forms and mixtures, due to its relatively low price and availability. This agent, however, contributes to the increase of salinity in the soil environment and may lead to disturbances in soil properties and premature plant necrosis. The impact of the usage of chloride salts on the soil environment was researched in Krakow's city centre by means of the examination of soil samples collected prior to the de-icing season (November) and afterwards (February) as well as snow samples taken in February. A general deterioration of the examined parameters (pH, conductivity, chloride concentrations, carbonate concentrations) was observed after the winter season, but still the results for most samples did not pose a serious threat to the soil environment or plants. This was mainly the result of the fact that the winter seasons in European countries have become increasingly mild and warm, which contributes to decreased usage of chloride salts. However, the state of soils in the Main Square was disturbing, as demonstrated by the clearly elevated chemical parameters of samples, despite a ban on the use of salt in this area. These results indicate the most probable reason for the withering of trees growing there, leading to them being frequently replaced.