Regeneration Performance Research Articles

Performance of a novel CO2 absorption and reverse electrodialysis system with different amine solutions for simultaneous energy and bicarbonate recovery

In this study, the performance of a novel integrated carbon dioxide (CO2) capture and reverse electrodialysis (RED) system was evaluated. The optimal operating conditions and carbon dioxide absorption and desorption mechanisms were identified. The proposed system utilizes a RED device to recover energy from the desorption step of the CO2 capture process, which is known to have high energy requirements in conventional processes. It has the potential as a hybrid process capable of recovering absorbent, energy, and bicarbonate through RED. To verify the performance of the system, CO2 loading, power density, and absorbent regeneration were evaluated using primary (monoethanolamine, MEA), secondary (diethanolamine, DEA), and tertiary (N-methyldiethanolamine, MDEA) amines. In the case of primary and secondary amines, carbamates, intermediate products, are formed and pass through the ion exchange membrane of RED, thereby achieving high power density. However, they are re-substituted with amines after passing through the ion exchange membrane (IEM), leading to the loss of absorbent. Conversely, in the case of tertiary amines, no intermediate products were formed, and excellent absorbent regeneration performance of more than 99.9% was demonstrated through multi-stage RED. Through this, the feasibility of future applications of this technology was confirmed.

Incorporation of copper ion promoted adsorption of anionic dye (Acid Yellow 36) by acrolein-crosslinked polyethyleneimine/chitosan hydrogel: Adsorption, dynamics, and mechanisms

In this study, a novel adsorbent, A-PEI/CS-Cu2+, was developed by crosslinking polyethyleneimine/chitosan hydrogel with acrolein and loading it with copper ions. The adsorption process of A-PEI/CS-Cu2+ on the anionic dye acid yellow 36 (AY36) was investigated by kinetic, isothermal and thermodynamic modeling. It was noteworthy that A-PEI/CS-Cu2+ exhibited rapid adsorption with a 90 % removal rate achieved within just 5 min, which was much faster than the adsorption rate of A-PEI/CS without load of copper ions and showed its potential for rapid adsorption applications. The maximum adsorption capacity for AY36 could reach up to 3114 mg g−1. In addition, the high concentration of saline wastewater was found to have almost no effect on the adsorption reaction in the salt effect test experiment. In five desorption-regeneration cycle experiments, the sample exhibited good recyclability and regeneration performance. The driving force of the adsorption process mainly originated from the electrostatic interaction, hydrogen bonding, and intermolecular interaction, in which the addition of copper ions led to the enhancement of the electrostatic interaction and chelation between A-PEI/CS-Cu2+ and AY36. Overall, the findings suggest the excellent potential of A-PEI/CS-Cu2+ for rapid and efficient adsorption, as well as its suitability for practical applications in wastewater treatment.

Modifications and applications of aerogel prepared with waste palm leaf cellulose in adsorptions for oily contaminations

Abstract Aerogels are essential and effective materials for oily pollution adsorption and recovery. This work described a hydrophobic modified cellulose aerogel using waste palm leaf and its oil adsorption mechanism. By chemical vapor deposition, Methyltrimethoxysilane (MTMS) was employed as a hydrophobic modifier for aerogel of waste palm leaf cellulose at 80 °C for 5 h, and the modified aerogel demonstrated exceptional and stable hydrophobicity with a water contact angle of 132.4° that can still be maintained above 120° after two months of air exposure. After 10 adsorption and extrusion cycles, kerosene adsorption capacity can still reach over 18 times its weight with good regeneration and reuse performance. The kinetic analysis found that the pseudo-second order model was more appropriate for the aerogel’s oil absorption process, including mainly physical adsorption at the beginning and the following chemical adsorption. Owing to its low cost, hydrophobicity, high absorption capacity, and favorable reusability, this aerogel is expected to be used in oils, organic solvent spill cleanup, and oil/water separation fields.

Convenient and highly efficient adsorption of diosmetin from lemon peel by magnetic surface molecularly imprinted polymers

As a typical bioflavonoid, diosmetin is desirable in the field of natural medicine, healthy food, and cosmetics by anti-cancer, antibacterial, antioxidant, estrogen-like and anti-inflammatory activities, and it comes from a wide range of sources in traditional Chinese medicine like spider fragrance, spearmint and chrysanthemum, as well as in Citrus fruit. However, traditional analytical methods such as silica gel column chromatography face multiple challenges in the selective extraction of diosmetin from biological materials and traditional Chinese medicinal materials. Therefore, it is urgent to develop a new type of absorbent with high efficiency, recyclability and good specificity to diosmetin. In this investigation, a magnetic surface molecularly imprinted polymer (labeled as Diosmetin/SMIPs) was synthesized employing magnetic nanoparticles as the carrier and 4-vinylpyridinyl (4-VP) as the functional monomer by surface imprinting technology. The functional monomer was screened by the binding energy (ΔE) between functional monomers and template molecules via computational simulation. The Diosmetin/SMIPs had a high level of specific recognition and adsorption capability towards diosmetin with a 20.25 mg g-1 adsorption capacity and an imprinting factor (IF) of 2.28. Additionally, it demonstrated excellent regeneration performance with 8 adsorption/desorption cycles. In addition, 91.20 %–94.16 % of spiked diosmetin was recovered from the lemon peel samples. The strategy of constructing Diosmetin/SMIPs based on computational simulation can effectively enhance the specific adsorption performance of diosmetin. Meanwhile, Diosmetin/SMIPs synthesized by imprinting polymerization showed excellent anti-interference and reusability, and realized efficient targeted extraction of diosmetin from lemon peel samples. The results of this investigation provide a promising adsorbent for selective enrichment of diosmetin from Citrus fruit and complicated materials.

Efficient adsorption of hexavalent chromium in water by torrefaction biochar from lignin-rich kiwifruit branches: The combination of experiment, 2D-COS and DFT calculation

A biochar (KBC) enriched with O functional groups was prepared by torrefaction using lignin-rich kiwifruit branches (KBM) as a raw material, which was characterized, and then KBC was used to adsorb hexavalent chromium (Cr6+) from water. The results showed that KBC contained more functional groups compared to KBM. The maximum adsorption of Cr6+ by KBC could reach 143.64 mg·g−1 and also had better adsorption performance than other adsorbents reported in some other reports. Cr6+ absorption by KBC was mainly a mechanism of electrostatic interaction and adsorption-reduction coupling. FTIR and XPS revealed that -OH, -COOH, CO and CC on KBC participated in Cr6+ adsorption and new groups (C=O) were generated during the process of adsorption, which implied that a redox reaction occurred. 2D-COS and DFT calculations showed that the order of functional groups on KBC interacting with Cr6+ was -OCH3 > -COOH > -OH > phenolic hydroxyl, and the binding tightness of the different functional groups to Cr6+ was -OCH3 (the shortest displacement of both groups after the adsorption) > -COOH > -OH > phenolic hydroxyl. KBC has good regeneration performance, and it is a good adsorbent for Cr6+.

Selective isolation of rubidium with mesoporous silica loaded with ammonium phosphomolybdate via an in-pore crystallization reaction

The scarcity of rubidium (Rb) in ore form makes it a valuable metal, prompting the need to develop reusable adsorbent materials for effective separation of rubidium (Rb+) from salt lake brine, which holds significant importance. Herein, a novel Rb+ selective composite adsorbent was prepared by in-pore crystallization. Macromesoporous silica was prepared using polyoxyethylene (10) octadecyl ether (Brij S10) as a templating agent and the effect of different templating agents on the pore size was investigated. An AMP-SiO2 composite adsorbent for Rb+ was obtained by “growing” ammonium phosphomolybdate on the macro-mesoporous silica by in-pore crystallization reaction. The results indicated that the adsorption of Rb+ by the AMP-SO2 adsorbent adhered to monolayer chemisorption, which was verified by fitting the adsorption data using the pseudo-second-order kinetics and the Langmuir isotherm model, respectively. The loading of AMP was 29.4 %, which increased the adsorption capacity by 115 %. Furthermore, the adsorption rate of Rb+ on AMP-SO2 when interfering ions were present still reached 73.2 % (KCl), 76.4 % (CaCl2), and 86.6 % (MgCl2). Density functional theory simulation indicated that AMP-SiO2 exhibited a higher adsorption energy for Rb+ (−9.79 eV) than K+, Li+, Ca2+, and Mg2+. The Rb 3d and Mo 3d X-ray photoelectron spectra of AMP-SiO2 before and after adsorption of Rb+, indicated that the ion-exchange process between rubidium and lattice cations is the controlling mechanism. In addition, AMP-SiO2 also showed good regeneration performance and maintained a high adsorption rate after five adsorption-resolution experiments. In summary, the AMP-SiO2 composite adsorbent can effectively expose adsorption sites and improve mass transfer efficiency, and has significant potential for future application in rubidium separation and extraction.

Study on regeneration mechanism of composite adsorbent by Mg-MOF-74-based modified biochar

In this paper, composite adsorbent was prepared from biochar and Mg-MOF-74 by in-situ growth method to investigate regeneration mechanism. The effects of O2 and temperature on regeneration characteristics were investigated by CO2 adsorption properties and characterization techniques, and the optimal regeneration conditions were determined. Regeneration mechanism of adsorbent was revealed by adsorption kinetics and elemental valence analysis. The related wave function parameters were calculated based on DFT to reveal the repair mechanism of the failed oxidation sites from the microscopic level. The mechanism of CO2 adsorption by the repaired oxidation sites was explored based on the regenerated adsorption configuration. It was found that the regeneration performance of the adsorbent exhibited a trend of increasing and then decreasing with the increase of O2 concentration and temperature, and the optimal regeneration conditions were determined to be 5 % O2 concentration and 200 °C. At optimal regeneration conditions, a synergistic interaction between O2 and poly-metals was generated to enhance the adsorbent polarity. O2 also reacted with the adsorbent in a redox reaction to produce new oxygen-containing functional groups and cause pore expansion, the mass transfer and diffusion was enhanced. The oxidation site adsorbed O2 to undergo electron rearrangement and release the adsorbed CO2. Due to the nature of common orbital hybridization between metals, the metals underwent conjugation and synergistic effects with O2 to form tetrahedral co-coordination structures with lower energies. The electron density and electric field effects of the system were enhanced. The former enhanced interaction with CO2 to form carbonate. The latter increased the activity of the neighboring N atom, which in turn generated a stable ring structure with carbonate, and CO2 adsorption was enhanced.

Imine-based conjugated polymer enables efficient removal of ammonium ion via capacitive deionization

The design of innovative faradaic electrode materials is crucial for improving the removal efficiency of contaminants in hybrid capacitive deionization (HCDI) systems. Organic compounds are a promising choice for faraday electrodes due to the sustainable production and tunable molecular structure. However, their high solubility in aqueous media and limited availability of redox-active sites for deionization greatly constrain the HCDI applications. Herein, we intentionally construct a conjugated polymer (IMP) with abundant imine groups, in which the strategic integration of N-heteroaromatic rings within the π-conjugated framework effectively prevents the disintegration of redox-active entities, while honing the energy bandgap and electronic characteristics. The copious redox-active CN sites within the imine groups along the polymeric chain markedly improve its capacity for the high-efficiency (de)intercalation of NH4+ ions. As an electrode material, the IMP polymer exhibits a significant NH4+-storage capacitance of 257.1 F g−1 at 2 A g−1 and maintains an ultra-cycle stability of 96.1 % after 10,000 cycles (4 A g−1), as evidenced by the in-situ spectral analysis of electrolyte. For real applications, a HCDI configuration has been constructed with a high specific NH4+ adsorption capacity of 119.0 mg g−1 and a fast removal rate of 27.0 mg g−1 min−1 with stable regeneration performance.

MgO modified sucrose-derived porous carbon composite for fluoride adsorption

Fluorine is an essential trace element for human skeletal and teeth health, while excess intake of fluoride induces many kinds of diseases. The national standard for fluoride concentration in drinking water quality in China is less than 1.0 mg L−1. Developing effective and environmental friendly approach to remove fluoride from water especially with high fluoride concentration in low cost is quite necessary. Herein, fluoride removal by MgO modified sucrose-derived porous carbon composite (MPCC) in batch and fixed-bed column systems was studied. The maximum fluoride adsorption capacity of MPCC was 26.6 mg g−1 at 25 ℃. Common anions Cl-, SO42- and NO3- showed negligible effect on fluoride removal, while a negative impact was observed with co-existence of HCO3-. The fluoride adsorption kinetic was well fitted with Langmuir adsorption model and the adsorption mechanism was ion exchange reaction between -OH and F-. The fluoride concentration can be successfully lowered down to the acceptable level of environmental standard for high concentration influent fluoride. The MPCC composite exhibited excellent regeneration performance, endowing it as promising adsorbent for remediation water with fluoride pollution.

Rape Pollen‐Based Composite Sorbent with Thermo‐Responsive and Photothermal Properties for Atmospheric Water Harvesting

AbstractSorption‐based atmospheric water harvesting (SAWH) has great potential for clean water acquisition and renewable energy use. Adsorption and desorption properties of sorbents play a crucial role in SAWH systems. However, most sorbents with high adsorption capacities are hindered by either slow sorption/desorption kinetics or poor regeneration performance. Here, a highly efficient block copolymer composite sorbent with dual functions of thermo‐responsive and photothermal properties is designed based on rape pollens. This sorbent has a hierarchical porous structure, in which the outermost layer of poly‐pyrrole enables it to convert light energy into heat and the second layer of poly(N‐isopropylacrylamide) imparts thermo‐responsive properties to improve the desorption ability. Meanwhile, confined LiCl improves its sorption capacity and cavities of the pollen can store captured moisture to avoid liquid leakage. This sorbent can sorb moisture to more than 144% of its own weight within 3 h under 20 °C&80% relative humidity (RH) and 82% of captured water can be released within 0.5 h under 1 sun. The water harvester using this sorbent can realize an exceptional water productivity of up to 2.21gwater gsorbent−1 day−1 only by three continuous water adsorption‐desorption cycles in a day. The high‐performance sorbent smooths the path for efficiently extracting water from the atmosphere to tackle water scarcity.

Ammonia gas adsorption study using copper impregnated on mesoporous activated carbon from seaweed waste for indoor air purification

Ammonia (NH3), as a toxic gas, has negative impacts on human health even at low concentration, especially in narrowed spaces. In this study, activated carbon was synthesized from seaweed waste and copper was loaded on its surface (Cu/AC filter) to prepare a cost-effective NH3 adsorbent. Pyrolysis (carbonization) temperature can significantly affect the texture properties of activated carbon, and the best activated carbon sample with BET of 1114 m2/g was obtained through pyrolysis at 500 °C followed by KOH-activation at 750 °C. Different from other lignocellulosic biomass-based activated carbons (mainly microporous structure), the prepared algae-based activated carbons mainly have a mesoporous structure (pore size: 7.0–9.0 nm). Copper-impregnation significantly changed the surface chemistry of activated carbon, thereby greatly increasing the NH3 adsorption capacity (max: 128.6 mg/g). The adsorption performance was primarily determined by chemical adsorption (caused by copper impregnation and related inherent functional groups, including O–H, C–H, O–Si–O and SiO–H), followed by physical adsorption (caused by BET). Isotherm studies indicated that NH3 adsorption on Cu/AC filter followed the Langmuir model, whereas the adsorption kinetics followed the pseudo-second-order model. Furthermore, the adsorption mechanism was controlled by intraparticle diffusion model with initial adsorption behavior. This can be attributed to the mesoporous structures of activated carbon, consequently dramatically improving the diffusion efficiency. In addition, the Cu/AC filter showed good regeneration performance, as it can still remain above 90 % after 5 cycles. Finally, this study demonstrated that the seaweed waste is a good precursor for activation carbon and has great potential as excellent NH3 adsorbent for indoor air purification.

Efficient microwave regeneration of iron-modified Na-based montmorillonite and Na-based attapulgite for enhanced adsorption of tetracycline in water

A novel iron-modified Na-based montmorillonite (Fe-MT) or iron-modified Na-based attapulgite (Fe-AT) adsorbent is successfully prepared using ion exchange method and applied to remove tetracycline (TC) in water, and the spent adsorbents saturated with organic pollutants are regenerated under microwave (MW) irradiation. The influences of the ratio of Fe3+ and cation exchange capacity, adsorption time, adsorbent dosage, MW power, and irradiation time are investigated. The possible adsorption and MW regeneration mechanism is also proposed. The results indicate that Fe-MT and Fe-AT have enhanced interlayer spacing and surface area after the Na-based montmorillonite (Na-MT) or Na-based attapulgite (Na-AT) are modified using Fe3+. 97.70 % and 95.04 % adsorption are obtained using Fe-MT and Fe-AT within 30.0 min at 298 K, respectively, while 78.54 % and 61.92 % adsorption are obtained using Na-MT and Na-AT, respectively. Also, the adsorption processes fit well with pseudo-second-order reaction kinetic and Freundlich model, signifying chemical and multilayered adsorption. The adsorption of TC using the above four adsorbents are spontaneous and endothermic. Moreover, MW regeneration can enhance the adsorption capacity of Fe-MT or Fe-AT, and the regeneration ratios can reach 98.82 % and 93.14 % under 800 W MW within 5.0 min, respectively. By comparison, the adsorption capacity, regeneration performance and reusability of Fe-MT with larger interlayer spacing and surface area are superior to that of Fe-AT. Therefore, this work provides new perspectives on the adsorption technique using modified clay minerals as adsorbents for dealing antibiotics in water and wastewater, and the MW regeneration technology for regenerating spent adsorbents saturated with organic pollutants.

Hyperbranched porous boronate affinity imprinted hydrogels for specific separation of flavonoids under physiological pH: A emulsion interfacial assembly imprinted strategy

Hydrogel-based molecular imprinted materials have attracted much attention in separation science and technology. However, traditional hydrogel imprinting sorbents face the limited number of imprinting sites, resulting in low adsorption capacity. Herein, a novel hyperbranched boronate affinity imprinted hydrogel (APOH-BA-MIPs) was prepared based on emulsion microreactors forthe specific separation of flavoniods. Interestingly, the new Pickering particles (CNCs@GMA@SH-A-CD) with hyperbranched anchor groups and suitable hydrophilic properties were fabricated, which significantly grafted the specific recognizing sites. Meanwhile, the cellulose nanocrystals (CNCs) and cyclodextrins (CDs) composite can effectively enhance the emulsion stability. The addition of functioned CNCs solid emulsifier would effectively enhance the mechanical stability of micro-nano imprinting assembly sorbents during the adsorption process. The mechanical properties of the resulting APOH-BA-MIPs were also improved (Young’s moduli 1.73 MPa). The results of adsorption experiments of APOH-BA-MIPs show fast adsorption kinetics (300 min) for NRG under pH = 7.4. The APOH-BA-MIPs still exhibited a significant adsorption capacity (56.03 μmol g−1at 308 K) for NRG compared to other structural analogues, such as CC, RT, QRCT, ARS and LTL. The imprinting factor (IF) of 3.24 was observed for APOH-BA-MIPs compared to their non-imprinted counterpart. The high affinity site number of APOH-BA-MIPs were calculated to be as high as 53.11 μmol g−1. The regeneration performance of APOH-BA-MIPs still remained at 93.75 % after seven adsorption–desorption cycles. Additionally, the purity can be extracted from agricultural waste pomelo peel to 91.37 %. The purified NRG exhibited excellent antibacterial properties against Staphylococcus aureus. This work provides a new strategy for the fabrication of micr-nano imprinted sorbents with abundant and uniform recognition sites for specific capture flavonoid molecules from agricultural waste.

Sustainable remediation of cadmium-contaminated soils: capture by Fe3O4/polyaniline and removal by magnetic separation

Cadmium (Cd) contamination of soil is a global environmental issue. Traditional remediation techniques such as immobilization, leaching and phytoextraction have numerous shortcomings, which has led to growing interest in the development of low cost, high-efficiency, and environmentally friendly agents for removing Cd from soil. In this study, Fe3O4/polyaniline (Fe3O4/PANI) was developed as a remediation agent with magnetic separation and regeneration capabilities. Its Cd adsorption isotherms showed a better fit to Langmuir model, exhibiting a high Cd adsorption capacity of 47.62 mg·g-1 at 25°C. In bench-scale experiments, Fe3O4/PANI was first attempted to remediating four typical Chinese soils with Cd concentration of 180 mg·kg-1: black, brown, cinnamon, and red. Results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91% and that the exchangeable Cd removal efficiency was 36.03% on average. In addition, the soil basic properties did not show major changes after remediation. Regarding the regeneration performance, after the first regeneration cycle, a better total Cd removal efficiency was achieved, i.e., 27.89%–44.96%. After two regeneration cycles, it decreased but still remained above 95% of the initial performance. Fe3O4/PANI has a simple and cost-effective synthetic process, and it combines high Cd removal efficiency with easy recovery and recyclability. It is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils, especially for the reclamation of highly contaminated development land.

Simultaneously enhancing toluene adsorption and regeneration process by hierarchical pore in activated coke: a combined experimental and adsorption kinetic modeling study.

Activated coke is a type of commonly used adsorbent for benzene series VOCs such as toluene, but traditional microporous activated coke usually faces the challenge of poor regeneration performance. Herein, based on self-made activated cokes with typical pore configuration, we found that adsorption and regeneration of toluene can be simultaneously enhanced by constructing hierarchical pore in activated coke. Correlations of pore configuration with toluene adsorption capacity and regeneration efficiency reveal that micropore contributes for strong toluene adsorption; meso-macropore provides mass transfer channel for toluene desorption and regeneration process. Hierarchical porous activated coke prepared from Zhundong subbituminous coal not only achieves the highest toluene adsorption capacity of 340.92mg·g-1, but also can retain more than 90% of initial adsorption capacity after five adsorption-regeneration cycles. By contrast, micropore-dominant activated cokes can only retain 70% of initial adsorption capacity. Adsorption kinetic modelling on adsorption breakthrough curves shows that hierarchical porous activated coke prepared from Zhundong subbituminous coal exhibits high adsorption and diffusion rate constants of 14.39 and 33.45min-1, respectively, much higher than those of micropore-dominant activated cokes. Due to the accelerated surface adsorption and diffusion processes induced by meso-macropore, toluene adsorption and regeneration behavior can be simultaneously improved. Results from this work validated the role of pore hierarchy in toluene adsorption-regeneration process, providing guidance for designing high-performance activated coke with synergistically improved toluene adsorption capacity and regeneration performance.

Low concentration adsorption of ammonia using metal halide loaded biogas residue-based carbon materials

Treating wastewater with elevated ammonia nitrogen levels in garbage treatment plants is a global concern, with blow-off recognized as an efficient process for nitrogen removal. However, this method generates low-concentration ammonia, presenting a challenge for adequate recovery. This study addresses this issue by impregnating metal halides onto K2CO3-activated biogas residue to create composite materials tailored for adsorbing low-concentration ammonia. We systematically investigated the impact of activation parameters, metal halide type, loading capacity, and environmental conditions on the adsorption properties of the materials. Notably, at an activation temperature of 700 °C, utilizing copper chloride with a loading capacity of 30 %, the material exhibited a saturation adsorption capacity of 29.32 mg/g for 200 ppm NH3, with a breakthrough time of 45.6 min, significantly surpassing the untreated sample and demonstrated excellent regeneration performance. SEM, BET, and FTIR analyses revealed that the material provided dispersion sites for metal halides, promoted the complexation of metal halides and ammonia and retained pores for ammonia diffusion, thereby enhancing adsorption efficiency. This innovative approach contributes to waste utilization and ensures efficient ammonia recovery through metal halide-ammonia complexation.

Thermal-hydraulic performance of TPMS-based regenerators in combined cycle aero-engine

The existing regenerator structure in aero-engine cannot satisfy the requirements with the development of hypersonic vehicles. The triply periodic minimal surface (TPMS) with superior thermal and mechanical performances has great potential for the regenerator. However, the study on TPMS structures as heat exchangers with high compactness and high power-to-weight ratio is still lacking. This study presents a complete workflow for evaluating the performances of TPMS heat exchangers. Based on this workflow, the thermal–hydraulic performances of Diamond, Fischer-Koch S (FKS), and printed circuit heat exchangers (PCHE) at different Reynolds numbers are investigated. Compared with the PCHE, the performance evaluation criteria of Diamond and FKS structures increased by 11.3–26% and 10.9–32.5%, respectively. This can be mainly attributed to the intensive turbulent mixing, large wall shear stress and high specific surface area of the TPMS structures. The thermal–hydraulic performance is also well explained by the field synergy principle. Based on the developed thermal and hydraulic correlations, the TPMS regenerators are designed and the results indicate that the power-to-weight ratio is improved by about 4 times with half volume of a PCHE. In summary, the TPMS regenerators can save space, reduce weight, and increase payload of aircrafts and have great application potential in the field of aerospace.

Adsorption studies of tetracycline hydrochloride and diclofenac sodium on NH2-MIL-53(Al/Zr) sodium alginate gel spheres

Metal-organic frameworks are emerging inorganic-organic hybrid materials that can be self-assembled from metal ions and organic ligands via coordination bonds. These materials possess large specific surface area, tunable pore structure, abundant active center, diversity of functional groups as well as high mechanical and thermal stability which promote their applications in adsorption and catalysis studies. In this study, NH2-MIL-53(Al/Zr) was prepared and embedded into sodium alginate gel spheres (NH2-MIL-53(Al/Zr)-SA) and its adsorption properties towards TC and DCF in solution were investigated. According to XRD and FTIR analysis, the structure of the raw material was not changed after making the gel spheres. The maximum adsorption towards TC (pH =3) and DCF (pH =5) reached 98.5 mg·g−1 and 192 mg·g−1, respectively. The process was consistent with Langmuir and Freundlich, suggesting that there was both monolayer and multilayer adsorption which infers the presence of physical adsorption (intra-particle diffusion) and non-homogeneous chemical adsorption. The thermodynamic parameters showed that the adsorption process was a spontaneous entropy increasing reaction. The regeneration rate of spent NH2-MIL-53(Al/Zr)-SA could still reach 99.1 % after three cycles, indicating good regeneration performance. This study can provide a basis for the application of NH2-MIL-53(Al/Zr)-SA in wastewater treatment.

Remodeling and Regenerative Properties of Fully Absorbable Meshes for Abdominal Wall Defect Repair: A Systematic Review and Meta-Analysis of Animal Studies.

Fully absorbable meshes can repair abdominal wall defects and effectively reduce the incidence of complications, but different types of fully absorbable meshes have different remodeling and regeneration effects. In order to investigate and compare the effects of different fully absorbable meshes on remodeling and regeneration in animals and reduce the biological risk of clinical translation, SYRCLE was adopted to evaluate the methodological quality of the included studies, and GRADE and ConQual were used to evaluate the quality of evidence. According to the inclusion and exclusion criteria, a total of 22 studies related to fully absorbable meshes were included in this systematic review. These results showed that fiber-based synthetic materials and fiber-based natural materials exhibited better restorative and regenerative effects indicated by infiltration and neovascularization, when compared with a porcine acellular dermal matrix. In addition, the human acellular dermal matrix was found to have a similar regenerative effect on the host extracellular matrix and scaffold degradation compared to the porcine acellular dermal matrix, porcine intestinal submucosa, and fiber-based natural materials, but it offered higher tensile strength than the other three. The quality of the evidence in this field was found to be poor. The reasons for downgrading were analyzed, and recommendations for future research included more rigor in study design, more transparency in result reporting, more standardization of animal models and follow-up time for better evaluation of the remodeling and regenerative performance of abdominal wall hernia repair meshes, and less biological risk in clinical translation.

Influence of physicochemical characteristics of calcium phosphate-based biomaterials in cranio-maxillofacial bone regeneration. A systematic literature review and meta-analysis of preclinical models

ObjectivesCalcium phosphate-based biomaterials (CaP) are the most widely used biomaterials to enhance bone regeneration in the treatment of alveolar bone deficiencies, cranio-maxillofacial and periodontal infrabony defects, with positive preclinical and clinical results reported. This systematic review aimed to assess the influence of the physicochemical properties of CaP biomaterials on the performance of bone regeneration in preclinical animal models. MethodsThe PubMed, EMBASE and Web of Science databases were searched to retrieve the preclinical studies investigating physicochemical characteristics of CaP biomaterials. The studies were screened for inclusion based on intervention (physicochemical characterization and in vivo evaluation) and reported measurable outcomes. ResultsA total of 1532 articles were retrieved and 58 studies were ultimately included in the systematic review. A wide range of physicochemical characteristics of CaP biomaterials was found to be assessed in the included studies. Despite a high degree of heterogeneity, the meta-analysis was performed on 39 studies and evidenced significant effects of biomaterial characteristics on their bone regeneration outcomes. The study specifically showed that macropore size, Ca/P ratio, and compressive strength exerted significant influence on the formation of newly regenerated bone. Moreover, factors such as particle size, Ca/P ratio, and surface area were found to impact bone-to-material contact during the regeneration process. In terms of biodegradability, the amount of residual graft was determined by macropore size, particle size, and compressive strength. ConclusionThe systematic review showed that the physicochemical characteristics of CaP biomaterials are highly determining for scaffold's performance, emphasizing its usefulness in designing the next generation of bone scaffolds to target higher rates of regeneration.