SBA-15 Adsorbents Research Articles

Synthesis and application of SBA-15 adsorbent for the removal of organic and inorganic substances.

This study investigates the adsorption of pollutants with different chemical structures; organic Naphtol Green B (NGB) dye and copper on a nanocomposite material with a hexagonal structure of the SBA-15 type. This research is divided into two main parts: the first carries out the synthesis of SBA-15 (Santa Barbra Amourphous) and its derivatives phases functionalized by 3-aminopropyl-triethoxylane (APTES) and calcined at 823K. The second part presents the influence of the adsorption conditions on the adsorption efficiency of NGB dye and copper. High-resolution X-ray diffractogram (XRD) showed three distinct peaks characteristic of highly ordered mesoporous material. Nitrogen adsorption-desorption isotherm of SBA-15 at 77K° is type IV typical of mesoporous materials. In addition, Fourier transform infrared spectroscopy (FT-IR) was also used in the characterization before and after the adsorption of the selected pollutants. At optimal conditions of pH 5.2, initial concentration of 50mg/L, adsorbent dosage of 20mg, and at adsorption time of 90min the maximum removal of pollutants reached 76% and the adsorption capacity was 227.25mg/g for NGB dye and 221.006mg/g for copper. Furthermore, the adsorption kinetics followed the pseudo-second-order model, indicating that chemisorption was the dominant mechanism and the Sips isotherm model best described the adsorption data. Our research demonstrates that the SBA-15 material after modification is an effective adsorbent for removing effluents regardless of their different chemical structure (organic and inorganic).

Selective recovery of europium from real acid mine drainage using modified Cr-MIL and SBA15 adsorbents

The successful adoption and widespread implementation of innovative acid mine drainage treatment and resource recovery methods hinge on their capacity to demonstrate enhanced performance, economic viability, and environmental sustainability compared to conventional approaches. Here, an evaluation of the efficacy of chromium-based metal–organic frameworks and amine-grafted SBA15 materials in adsorbing europium (Eu) from actual mining wastewater was conducted. The adsorbents underwent comprehensive characterization and examination for their affinity for Eu. Cr-MIL-PMIDA and SBA15-NH-PMIDA had a highest Langmuir adsorption capacity of 69 mg/g and 86 mg/g, respectively, for an optimum level of pH 4.8. Preferential adsorption tests followed using real AMD collected at a disused mine in the north of Norway. A comparative study utilizing pH-adjusted real AMD revealed that Cr-MIL-PMIDA (88%) exhibited slightly higher selectivity towards Eu compared to SBA15-NH-PMIDA (81%) in real mining wastewater. While Cr-MIL-PMIDA displays excellent properties for the selective recovery of REEs, practical challenges related to production costs and potential susceptibility to chromium leaching make it less appealing for widespread applications. A cost–benefit analysis was then undertaken to quantify the advantages of employing SBA15-NH-PMIDA material. The study disclosed that 193.2 g of EuCl3 with 99% purity can be recovered by treating 1000 m3 of AMD.

Studying the kinetics and removal mechanism of the methylene blue dye in a continuous adsorption process using prepared mesoporous materials

ABSTRACT This study investigated the removal of a typical organic pollutant methylene blue (MB) dye from wastewater by a prepared mesoporous SBA-15 adsorbent in a continuous adsorption system (fixed-bed column). The structural and textural properties of the SBA-15 adsorbent were determined using different characterization techniques. The adsorption of continuous system experiments assessed the bed height effect, initial concentration, and flow rate on a breakthrough curve. The kinetic constants and breakthrough curves were obtained using the Thomas and Yan models. The breakthrough results revealed that SBA-15 has an excellent adsorption efficiency for use in the continuous adsorption system. The findings explain that MB removal achieved the maximum uptake (84 mg/g) at 6 cm of bed height, 0.5 mL/min of flow rate, and 30 mg/L initial concentration of MB. SBA-15 can be efficiently regenerated by calcination and re-employed 5 times in a fixed-bed system without a significant loss in its adsorption capacity of MB from MB solutions. As a result, SBA-15 was determined as the appropriate media to be adsorbent for MB. This study suggests that the prepared SBA-15 is feasible to use effectively for MB removal from the wastewater.

Facilely tuning the morphologies of tertiary amine-functionalized SBA-15 for optimizing selective SO2 capture

The amine-based materials pose high potential for the adsorption of sulfur dioxide (SO2). This work is aimed at modulating the morphologies of SBA-15 adsorbents by controlling the precursor self-assembly processes, for the sake of optimizing the utilization efficiency of amine species in the polytertiary amine (PTA)-functionalized SBA-15. It results that worm-like SBA-15 (WLS) material shows a better particle aspect ratio and well-defined pore structure, which helps to optimize the adsorption sites invoked by the preferable dispersion and exposure of PTA, thus amplifying the chemisorption of SO2 on the adsorbent. Consequently, the functionalized WLS-PTA adsorbent exhibits remarkable SO2 adsorption performance (15.43 mmol/g), exceptionally high selectivities of SO2/N2 (27522) and SO2/CO2 (652). Surprisingly, the desulfurization capacity can be further enhanced by the positive effect of the water vapor co-fed. It is unveiled that the whole SO2 adsorption process mainly follows the dual site Langmuir-Freundlich isotherm model and Bangham model. This work sheds light on the design of polymer-solid composite adsorbents for selective capture of SO2.

Selective recovery of europium from real acid mine drainage by using novel amine based modified SBA15 adsorbent and membrane distillation system

Recovery of rare earth elements (REE) from secondary waste streams promises numerous advantages. Europium (Eu) is an essential component in various high-tech applications, including clean energy technologies. Ensuring a stable supply of europium through recycling reduces the vulnerability to supply disruptions and price fluctuations in the global market. To achieve this, there is a need for development of highly selective and commercially viable adsorbents for Eu recovery. This research presents a novel material, SBA15-NH-PMIDA, synthesized through a two-step surface modification process for selective retrieval of Eu from real acid mine drainage (AMD). Initially, comprehensive physical and chemical characterizations of the material were conducted to confirm its successful synthesis. Subsequent single-solute Eu adsorption experiments demonstrated that SBA15-NH-PMIDA achieved equilibrium within 2 h and exhibited a maximum Langmuir adsorption capacity of 86.21 mg/g at optimal pH of 4.8. It exhibited remarkable selectivity in recovering over 80 % of Eu from pH-adjusted real AMD, with an optimal dosage of 0.8 g/L. Next, a hybrid system amalgamating Direct Contact Membrane Distillation (DCMD) and adsorption was devised. This hybrid system involved the suspension of granulated SBA15-NH-PMIDA within the feed tank to treat pH-adjusted AMD. The DCMD system achieved an 80 % recovery of purified water while concentrating Eu ions by more than threefold, facilitating efficient and selective Eu recovery surpassing 90 %. Importantly, the uptake of other competing metals remained below 10 %. This is attributed to the formation of Eu complexes with phosphonic and carboxyl acid functional groups. SBA15-NH-PMIDA demonstrated its sustainability and viability by consistently retaining over 90 % of its adsorption capacity throughout ten regeneration cycles.

Functionalization of SBA-15 mesoporous silica for highly efficient adsorption of glutathione: Characterization and modeling studies

BackgroundPristine SBA-15 and amine or thiol-functionalized SBA-15 materials were synthesized, characterized, and highlighted by studying the glutathione (GSH) adsorption process in aqueous solutions. MethodsIn this study, SBA-15 mesoporous materials were functionalized with 3-aminopropyltriethoxysilane (APTS) and (3-mercaptopropyl)triethoxysilane (MPTES) in order to introduce amine and thiol groups onto the surface by using a post-grafting method, respectively. For comparison, the SBA-15-based materials were used as adsorbents to further investigate the adsorption behaviour of GSH under various experimental conditions. Significant findingsTo examine the underlying mechanism of the adsorption process, the kinetics of the GSH adsorption onto SBA-15-based adsorbents were fitted using pseudo-first order, pseudo-second order, Elovich, and Aharoni models. Adsorption isotherms showed that the Freundlich isotherm model was the most appropriate to simulate the adsorption of GSH molecules onto SBA-15-NH2 adsorbent and the Langmuir isotherm model for the two other substrates. In addition, the adsorption thermodynamics confirmed the exothermic behaviour of GSH adsorption process onto the SBA-15-SH adsorbent. In contrast, the capture of GSH molecules by the SBA-15-OH and SBA-15-NH2 adsorbents follows an endothermic reaction process. Finally, the adsorption nature of GSH onto SBA-15 adsorbents is classified as physisorption.

Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)

The aim of this study is to determine and compare the adsorption capacities, kinetic and thermodynamic parameters of the adsorption process of uranyl ions from aqueous solution on nanotube titania impregnated mesoporous silica SBA-15 (TNT-SBA-15) and naked SBA-15 (nSBA-15) adsorbents. The TNT-SBA-15 composite containing various molar ratio of nanotube titania to silica (TNT-SBA-15(m:n)) in the matrix was synthesized by the sol–gel/impregnation method using sodium silicate as a silica precursor, sulphuric acid and nanotube titania. Batch adsorption experiments showed that the maximum adsorption capacity (qmax) of the TNT-SBA-15(m:n = 1:1) composite under indoor light be as high as 2.65 mMoleU g−1 that was 1.4 times higher than that of nSBA-15 under the same conditions. Under UV (300 W) illumination the qmax of TNT-SBA-15(1:1) adsorbent reached 3.49 mMoleU g−1 that was 2 times higher than the qmax in the dark. The increase in qmax of the TNT-SBA-15(1:1) composite in the two experiments was attributed to the synergistic effect of coupled sorption and photocatalytic reduction of U(VI) by titania following the deposition of uranium (IV) (hydr)oxide on the surface of the adsorbent. The adsorption process followed a pseudo-second kinetic model. The activation energy was found to be 160 and 135 kJ Mole−1 for the adsorption on nSBA-15 and TNT-SBA-15(1:1), respectively. The isotherm of the adsorption process follows the Langmuir as well as Freundlich models. The adsorption is an endothermic and spontaneous process. Adsorbed TNT-SBA-15 can be easily regenerated in 0.3 M HNO3 solution, and the qmax of the adsorbent was maintained at 95% the initial qmax after three consecutive adsorption–desorption cycles. These results revealed that, though TNT-SBA-15 made from inexpensive reagents could be an effective adsorbent for uranyl removal from wastewater.

Hydrogen sulfide removal from low concentration gas streams using metal supported mesoporous silica SBA-15 adsorbent

The removal of hydrogen sulfide (H2S) from gas mixtures is paramount as it can cause environmental damage, corrosion, and catalyst poisoning even at low concentration levels (100–200 mg/L). In this work, a series of Fe-Cu oxides supported SBA-15 materials were prepared using the wet incipient impregnation method with different Fe and Cu atomic ratios to evaluate the H2S removal performance. It was found that the H2S adsorption capacity generally increases with an increase in the CuO loading, with a Cu-Fe atomic ratio of 1.0:0.3 displaying the highest breakthrough H2S adsorption capacity of 74.08 mg H2S/g-sorbent. Through the XPS results, the adsorbent existed in the form of sulfate, sulfide, and elemental sulfur after reacting with H2S. In particular, it was confirmed that Fe2O3 helps to improve the H2S removal performance by creating an alkaline environment. The material with superior performance showed high capacity at low concentration compared to several published reports.

Effective adsorption and immobilization of Cr(VI) and U(VI) from aqueous solution by magnetic amine-functionalized SBA-15

• A magnetic amine-functionalized SBA-15 was fabricated successfully. • Adsorption conditions played an important role in uptake of Cr(VI) and U(VI). • Adsorbents exhibited satisfying adsorption performance for Cr(VI) and U(VI). • Adsorption mechanism was conformed by SEM, FT-IR and XPS techniques. Herein, a magnetic amine-functionalized mesoporous silica SBA-15 (Fe 3 O 4 @SBA-15-PDA/HBP-NH 2 ) adsorbent was fabricated by loading Fe 3 O 4 nano-particles on amino-terminated hyperbranched polymers (HBP-NH 2 ) functionalized SBA-15 and exploited for chromium (VI) and uranium (VI) elimination. The morphologies and microstructures of as-obtained materials were observed using different physicochemical and spectroscopic techniques. Meanwhile, batch experiments were performed to investigate the impacts of various water environment conditions on removal process including solution pH, equilibrium time and temperatures. The maximum adsorption capacities of U(VI) and Cr(VI) on Fe 3 O 4 @SBA-15-PDA/HBP-NH 2 reached up to 77.4 mg/g and 66.5 mg/g under optimal water environment conditions. Moreover, the characterization analysis manifested that removal of U(VI) was fulfilled through the surface complexation with amino and phenolic hydroxyl groups, while Cr(VI) were firstly electrostatically adsorbed, and subsequently reduced to less toxic Cr(III) by phenolic hydroxyl groups. These findings demonstrated that this new magnetic amine-functionalized SBA-15 could be considered as valuable materials in environmental cleanup.

Synthesis of spherical SBA-15 by poly (vinyl alcohol)/ Hydroxyl-terminated polybutadiene supermicelles as co-surfactant and its application for removal of diazinon from aqueous solution

A low-cost and facile strategy was successfully developed to produce spherical micrometer-sized SBA-15 with cylindrical pores arranged in a hexagonal order using pluronic triblock-copolymer P123 as template and poly (vinyl alcohol) (PVA)/hydroxyl-terminated polybutadiene (HTPB) supermicelles as co-surfactant. Herein, a solvent evaporation induced aggregating assembly (EIAA) method was reported for the preparation of SBA-15 microspheres. The materials were characterized by Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmet–Teller (BET) method. The diazinon adsorption properties of spherical SBA-15 were studied to find out the effect of various experimental factors. Results exhibited that the highest diazinon removal efficiency (95.2%) was achieved at pH 6, initial concentration of 50 mg L −1 , temperature of 318 K, and the adsorbent dosage of 0.1 g L −1 for 60 min. The adsorption behavior of diazinon was described by the Langmuir isotherm and pseudo-second-order model (R 2 > 0.99). Maximum adsorption capacity obtained 526.3 mg g −1 . The apparent activation energy for spherical SBA-15 was 16.69 kJ mol −1 . Thermodynamic studies illustrated that the adsorption process was exothermic with spontaneous nature. The efficiency of diazinon removal was not considerably affected by the presence of the lindane. Moreover, the spherical SBA-15 retained its adsorbing properties after sixteen cycles. • Spheres obtained using P123–PVA/HTPB as a template in the THF/H 2 O/ethanol mixture. • Spherical SBA-15 adsorbent was highly effective to diazinon removal. • The adsorption process was described by the Langmuir isotherm. • The pseudo-second-order model is the best to adsorption kinetic.

Amino groups modified SBA-15 for dispersive-solid phase extraction in the analysis of micropollutants by QuEchERS approach

In the analysis of contaminants in food products, sample preparation is performed by proper adsorbents, whose choice is crucial to eliminate matrix interference. In this work we modified SBA-15 adsorbents by functionalization with (3-aminopropyl)-triethoxysilane (SBA-15-APTES) and N-[3-(trimethoxysilyl)propyl]aniline (SBA-15-AN) aiming to use them for the first time in the clean-up step of a QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction of micropollutants from strawberry, a sugar rich fruit. After physico-chemical characterization by nitrogen adsorption, infrared spectroscopy and thermogravimetric analysis, the adsorption capabilities of SBA-15 sorbents and possible interaction mechanisms were studied at different pH (2.1-8.5) for glucose, sucrose and fructose at concentrations characteristic of those found in strawberries. The performance of the two SBA-15 sorbents was compared with that of commercial PSA (primary secondary amine), usually proposed in QuEChERS protocols. Both SBA-15 materials exhibit up to 30% higher adsorption than PSA, suggesting their possible QuEChERS application. Synthesized SBA-15 adsorbents were hence used as innovative dispersive sorbents in the QuEChERS extractions of 13 PAHs and 14 PCBs from strawberry. For PCBs, SBA-15-AN provides better matrix removal than PSA and comparable extraction recoveries around 90%. For PAHs, the use of SBA-15-AN has the advantage of lower relative standard deviation (7%) than PSA (19%).

Empirical Assessment and Reusability of an Eco-Friendly Amine-Functionalized SBA-15 Adsorbent for Aqueous Ivermectin

Ivermectin has efficacious broad-spectrum action against several human and veterinary endo-/ectoparasites. However, it is an emerging contaminant in water, causing serious concern to environmental ...

Meso- and macroporous silica-based arsenic adsorbents: effect of pore size, nature of the active phase, and silicon release.

Arsenic pollution in ground and drinking water is a major problem worldwide due to the natural abundance of arsenic by dissolution from ground sediment or mining activities from anthropogenic activities. To overcome this issue, iron oxides as low-cost and non-toxic materials, have been widely studied as efficient adsorbents for arsenic removal, including when dispersed within porous silica supports. In this study, two head-to-head comparisons were developed to highlight the As(v)-adsorptive ability of meso- and macrostructured silica-based adsorbents. First, the role of the textural properties of a meso-(SBA15) and macrostructured (MOSF) silica support in affecting the structural-morphological features and the adsorption capacity of the active phase (Fe2O3) have been studied. Secondly, a comparison of the arsenic removal ability of inorganic (Fe2O3) and organic (amino groups) active phases was carried out on SBA15. Finally, since silica supports are commonly proposed for both environmental and biomedical applications as active phase carriers, we have investigated secondary silicon and iron pollution. The batch tests at different pH revealed better performance from both Fe2O3-composites at pH 3. The values of qm of 7.9 mg g−1 (53 mg gact−1) and 5.5 mg g−1 (37 mg gact−1) were obtained for SBA15 and MOSF, respectively (gact stands for mass of the active phase). The results suggest that mesostructured materials are more suitable for dispersing active phases as adsorbents for water treatment, due to the obtainment of very small Fe2O3 NPs (about 5 nm). Besides studying the influence of the pore size of SBA15 and MOSF on the adsorption process, the impact of the functionalization was analyzed on SBA15 as the most promising sample for As(v)-removal. The amino-functionalized SBA15 adsorbent (3-aminopropyltriethoxysilane, APTES) exhibited a qm of 12.4 mg g−1 and faster kinetics. Furthermore, issues associated with the release of iron and silicon during the sorption process, causing secondary pollution, were evaluated and critically discussed.

Preparation of 2-hydroxy-1-naphthalene Functionalized SBA-15 Adsorbent for the Adsorption of Chromium(III) Ions from Aqueous Solution

Preparation of 2-hydroxy-1-naphthalene Functionalized SBA-15 Adsorbent for the Adsorption of Chromium(III) Ions from Aqueous Solution

Enhanced and selective adsorption of urea and creatinine on amine-functionalized mesoporous silica SBA-15 via hydrogen bonding

In this study, mesoporous silica SBA-15 particles were synthesized using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) and tetraethoxysilane as the precursors and were subsequently modified with 3-aminopropyl triethoxysilane (APTES). The amine-functionalized particles were characterized using field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, N2 sorptiometry, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, and thermogravimetric analysis. The prepared materials were subsequently used for the adsorption removal of small uremic toxins, namely urea, creatinine, and hippuric acid. The adsorption of these single toxins from synthetic serum samples on SBA-15–based adsorbents followed a pseudo-second-order kinetic model, and the adsorption was well described by the Langmuir isotherm. It was determined that the adsorption capacity of SBA-15 for urea and creatinine was increased after APTES functionalization. The highest adsorption capacities of SBA-15 modified with 0.2 mol/L APTES in toluene for urea and creatinine were 1644.7 and 181.7 mg/g, respectively, at 37 °C, whereas the highest adsorption capacity of pristine SBA-15 for hippuric acid was 111.7 mg/g. Preferential and competitive hydrogen bonding-promoted adsorption of urea over hippuric acid in binary mixtures occurred for the APTES-modified SBA-15 adsorbents, as demonstrated using the FTIR spectra of the adsorbents before and after adsorption.

Synthesis of quaternized mesoporous silica SBA-15 with different alkyl chain lengths for selective nitrate removal from aqueous solutions

Abstract In this study, five different quaternary ammonium functionalized-mesoporous silica SBA-15 adsorbents with different alkyl chain lengths (C1Q-, C4Q-, C8Q-, C12Q-, and C18Q-SBA-15) were synthesized. This study focused on the effect of alkyl chain length of quaternary ammonium silane coupling agent grafted to SBA-15 on the selective nitrate removal from aqueous solutions. Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra confirmed that quaternary ammonium functional groups were successfully grafted onto the surface of SBA-15. In the FTIR spectra of C8Q-, C12Q-, and C18Q-SBA-15, peaks of CH2 asymmetric and CH2 symmetric stretching appeared at 2922–2944 cm−1 and 2852–2856 cm−1, respectively, which were getting stronger with an increase of alkyl chain length. In the N 1s spectra of the quaternized SBA-15, new peaks of NH4NO3 appeared at 405.8–406.2 eV after removal experiments, providing evidence of nitrate removal. The observed 13C solid-NMR spectra of the quaternized SBA-15 demonstrated that the quaternization occurred successfully on the adsorbents. Batch experiments demonstrated that the quaternized SBA-15 could effectively remove nitrate in the pH range from 4 to 10. The nitrate removal by the quaternized SBA-15 was fast process with equilibrium time of 10 min for C1Q- and C4Q-SBA-15 and of 30 min for C8Q-, C12Q-, and C18Q-SBA-15. The maximum nitrate removal capacities (mg/g) were in the order of C8Q-SBA-15 (136.4) > C4Q-SBA-15 (129.9) > C1Q-SBA-15 (89.4) > C12Q-SBA-15 (71.9) > C18Q-SBA-15 (30.7). In the presence of competing anions (chloride, phosphate, bicarbonate, and sulfate), C8Q-and C12Q-SBA-15 were more effective for nitrate removal than C1Q- and C4Q-SBA-15. In ground water (pH = 7.6, chloride = 47.7 mg/L, nitrate = 153.8 mg/L, sulfate = 445.4 mg/L; bicarbonate = 20.2 mg/L), C8Q- and C12Q-SBA-15 had nitrate-to-sulfate separation factors ( α S N ) of >3.7, whereas C1Q- and C4Q-SBA-15 had the α S N values of

Desulfurization process: understanding of the behaviour of the CuO/SBA-15 type SOx adsorbent in the presence of NO/NO2 and CO/CO2 flue gas environmental pollutants

SOx (i.e. SO2 and SO3) compounds are known to be a major source of atmospheric pollution and to be responsible of adverse effects on the human health and on the environment. To reduce the SOx emissions, numerous abatement technologies were developed and applied. Nowadays, the most attractive one seems to be the process that use a regenerable SOx adsorbent. In this respect, a CuO (15 wt.%)/SBA-15 regenerable type SOx adsorbent has been developed. Under standard conditions (a gaseous mixture of N2, SO2 and O2), the adsorbent exhibits a stable adsorption capacity around 50 mgSO2/gads along 10 cycles at 400 °C (for a 75 ppm of SO2 exhaust concentration). The main aim of this work is to study the impact of various regulated pollutants such as CO, CO2, NO and NO2 on the SO2 adsorption capacity of the CuO (15 wt.%)/SBA-15 adsorbent. In the presence of CO and CO2, the SO2 adsorption performance of the CuO/SBA adsorbent is similar to the one observed under standard conditions. On the other hand, under NO and NO2 atmosphere, the dynamic and total adsorption capacities of the adsorbent are enhanced up to 25% and no deactivation occurs along the cycles. The increase may be related with the synergetic effect between NO2 and SO2 towards the sulphate formation. The CuO/SBA-15 adsorbent before and after multicycle SO2 adsorption in the presence of regulated pollutants and regeneration under 0.5 vol.% of H2 have been characterized by XRD and N2 physisorption. No significant structural and textural change is observed compared to the CuO/SBA-SO2 adsorbent.

Unmodified SBA-15 adsorbents for the removal and separation of Th(IV) and U(VI) ions: the role of pore channels and surface-active sites

ABSTRACTThe removal of Th(IV) and U(VI) by calcinated, non-calcinated, and methyl grafted SBA-15 (abbreviated as SBA-15, SBA-15-NC and SBA-15-MG, correspondingly) were compared to elucidate the role of pores and surface adsorption sites on SBA-15 adsorbents. It was proposed that the contribution of pores and surface-active sites of SBA-15 increases its higher adsorption capacity with respect to the other examined adsorbents. The kinetic studies revealed that the adsorption and also desorption occurred initially on the surface and then to the pores. Adsorption/desorption of the ions into pores was occurred with slow kinetics.

Adsorption of Contaminants of Emerging Concern from Aqueous Solutions using Cu2+ Amino Grafted SBA-15 Mesoporous Silica: Multicomponent and Metabolites Adsorption

SBA-15 and Cu2+ amino grafted SBA-15 adsorbents (CuNH2_g_SBA-15) were prepared to investigate the equilibrium and dynamic adsorptive removal of a set of contaminants of emerging concern (CECs; carbamazepine, caffeine, clofibric acid, salicylic acid, and naproxen) from water. Multicomponent and CEC metabolites adsorption was also evaluated to elucidate effects on adsorption capacity and selectivity. Equilibrium adsorption studies showed that CuNH2_g_SBA-15 is capable of removing anionic and acidic CECs even at trace level concentrations. However, multicomponent tests revealed a decrease of 30% in adsorption capacity in the case of the acids. The CuNH2_g_SBA-15 variant was less affected by multicomponent competitive adsorption, probably due to the ability of this adsorbent to interact with CECs through several, simultaneous adsorption mechanisms (i.e., electrostatic interaction, hydrogen bonds, and metal coordination complexes). These were confirmed via X-ray photoelectron spectroscopy (XPS) analyses. Preliminary fixed-bed adsorption tests showed that beds made of CuNH2_g_SBA-15 are prone to mass-transfer resistance in comparison to those made of unmodified SBA-15, causing a decrease in both adsorption capacity and degree of bed utilization. Adsorption of parent/metabolites CEC binary mixtures resulted in a reduction in adsorption capacity of the parent CECs, but the adsorbents showed a remarkable selectivity toward the metabolites, particularly CuNH2_g_SBA-15. In general, this study provides substantial evidence that the anchoring of amine/copper species onto the surface of mesoporous silica may provide a platform for the development of CEC selective adsorbents for water treatment.

Granulation of short channel SBA-15 adsorbent and application for the removal of U(VI) by packed column

In order to reduce the loss of particles during the cycling operation, a technology for the granulation of short channel SBA-15 adsorbent was developed. The adsorption behavior of obtained granules was studied under various factors including initial pH value, contact time in different initial concentration and acid stability by batch experiments. A continuous packed column loaded with granules was performed to remove U(VI) from aqueous solution. The uranium concentration was highly enriched than feed solution. The granules packed in column exhibited excellent reusability through cycling test. The result showed promising application prospect in the uranium extraction from aqueous solution.