An effective algaecide for the targeted destruction of Karenia brevis.

We address the targeted destruction of Karenia brevis using the algaecide calcium peroxide, in tandem with the flocculation and sinking of the species. The specific aspect of the approach is the incorporation of the algaecide within the floc to rapidly kill K. brevis, thus minimizing escape of cells from the floc and reentry to the water column. CaO2 gradually produces H2O2, which diffuses through cell membranes and induces oxidative stress, leading to cell death via excessive reactive oxygen species (ROS) formation. The effect of varying doses of calcium peroxide on K. brevis cells was measured with pulse amplitude modulated fluorometry and indicated that doses as low as 30 mg/L when integrated into flocs are effective in suppressing photosynthesis. Cell viability assays also indicate that such low levels are sufficient to cause cell death in a 3-6 hour time period. Thus, the proposed technology involving the incorporation of calcium peroxide in a cationic flocculating agent (polyaluminum chloride, PAC) leads to an inexpensive and scalable technology to mitigate harmful algal blooms of K. brevis.

Aluminum hydroxide and immunostimulatory glycolipid adjuvant combination for enhanced COVID-19 subunit vaccine immunogenicity.

Protein-based subunit vaccines like RBD-Fc are promising tools to fight COVID-19. RBD-Fc fuses the receptor-binding domain (RBD) of the SARS-CoV-2 virus spike protein with the Fc region of human IgG1, making it more immunogenic than RBD alone. Earlier work showed that combining RBD-Fc with iNKT cell agonists as adjuvants improved neutralizing antibodies but did not sufficiently enhance T cell responses, a limitation RBD-Fc vaccines share with common adjuvants. Here we demonstrate that aluminum hydroxide combined with α-C-GC, a C-glycoside iNKT cell agonist, significantly improved the RBD-Fc vaccine's induction of RBD-specific T-cell responses. Additionally, aluminum hydroxide with α-GC-CPOEt, a phosphonate diester derivative, synergistically elicited more robust neutralizing antibodies. Remarkably, modifying αGC with phosphate (OPO3H2) or phosphonate (CPO3H2) to potentially enhance aluminum hydroxide interaction did not improve efficacy over unmodified αGC with aluminum hydroxide. These findings underscore the straightforward yet potent potential of this approach in advancing COVID-19 vaccine development and provide insights for iNKT cell-based immunotherapy.

Recycling aluminum from polyaluminum chloride sludge through acid dissolution and cation resin separation/purification.

To recycle aluminum (Al) from waterworks sludge resulting from polyaluminum chloride (PAC) used as coagulants, this study proposed an innovative strong acidic cation (SAC) exchange resin treatment strategy for Al separation from coexisting fulvic acid (FA) and heavy metals (HMs) in the H2SO4 leachate of PAC sludge. Fluorescence titration confirmed the breakdown of the Al-FA complex at pH 2.0, which facilitated Al separation from FA in the acidic leachate. The species distribution of the dissociated Al (i.e. Ala, Alb, and Alc) significantly influenced the adsorption of Al onto the cation exchange resin. The continuous release of H+ during the cation exchange reaction greatly promoted the transformation of dissociated Alc and Alb into Ala, thereby improving the adsorption of total Al. Moreover, the SAC resin column successfully separated the codissolved HMs from the Al in the leachate even at an influent pH of 2.8, which was attributed to the greater selectivity of the sulfonate groups on the cation exchange resin for free Al3+. The Al eluted from the exhausted resin with 1.1 M H2SO4 was collected as the recycled coagulant after proper pH adjustment. The Al adsorption capacity of the SAC resin decreased by approximately 5 % with each operation cycle and was regained by complete regeneration with 1.8 M H2SO4 after 5 cycles. Overall, the integrated efficiency of Al recovery from PAC sludge by H2SO4 acidification and SAC resin separation/purification reached 70.10 %. The recycled Al from sludge has a water treatment performance comparable to that of fresh PAC coagulant.

New insights into membrane fouling in coagulation-ultrafiltration by cake characteristics analysis: A case study with PACl-Al13 and PACl.

Membrane fouling is a bottleneck issue that hindered the further application of ultrafiltration technology. To alleviate membrane fouling, coagulation-ultrafiltration (C-UF) process using polyaluminum chloride (PACl) and PACl-Al13 with high proportion of Al13O4(OH)247+ as coagulants, respectively, were investigated at various pH conditions. Results indicated that an increase in solution pH contributed to larger floc size and looser floc structure for both PACl and PACl-Al13. It was conducive to the formation of more porous cake, as evidenced by mean pore area and pore area distribution of cake, leading to lower reversible fouling. Furthermore, humic acid (HA) removal presented a trend of first increasing and then decreasing with the increase of pH. The optimal HA removal was achieved at pH 6 regardless of coagulant type, suggesting that the slightest irreversible fouling should be occurred at this point. Interestingly, the irreversible fouling with PACl coagulant achieved a minimum value at pH 9, while the minimal irreversible fouling with PACl-Al13 was observed at pH 6. We speculated that the cake formed by PACl could further intercept HA prior to UF process at alkaline pH. Furthermore, compared with PACl, PACl-Al13 had a stronger charge neutralization ability, thus contributing to more compact floc structure and higher HA removal at various pH conditions. By UF fractionation measurement, higher HA removal for PACl-Al13 was due to higher removal of HA with molecular weight less than 50 kDa.

Solid Phase Peptide Carrier Conjugation.

Conjugation to carrier proteins is necessary for peptides to be able to induce antibody formation when injected into animals together with a suitable adjuvant. This is usually performed by conjugation in solution followed by mixing with the adjuvant. Alternatively, the carrier may be adsorbed onto a solid support followed by activation and conjugation with the peptide by solid-phase chemistry. Different reagents can be used for conjugation through peptide functional groups (-SH, -NH2, -COOH), and various carrier proteins may be used depending on the peptides and the intended use of the antibodies. The solid phase may be an ion exchange matrix, from which the conjugate can subsequently be eluted and mixed with adjuvant. Alternatively, the adjuvant aluminum hydroxide may be used as the solid-phase matrix, whereupon the carrier is immobilized and conjugated with peptide. The resulting adjuvant-carrier-peptide complexes may then be used directly for immunization.

Optimization of turbidity removal and floc formation for ballasted flocculation using magnetite-based agents by response surface methodology.

In this study, a static mixer was used as an alternative to the existing flash mixing method for ballasted flocculation to assess the turbidity removal and ballasted floc formation characteristics. Synthetic magnetite exhibits excellent properties, such as high specific gravity, hydrophobicity, and wear resistance, making it a suitable ballast agent (BA). The experimental design was optimized using the response surface methodology. To evaluate turbidity removal, a model based on polyaluminum chloride dosage, BA surface charge, and pH was developed. To assess the ballasted floc characteristics, the BA dosage, BA size, and G value of the static mixer were used. During ballasted flocculation, the impact of the zeta potential of the BA was minimal. Consequently, bonding primarily resulted from the viscosity of the floc caused by physical collisions rather than electrostatic forces stemming from the BA charge. The findings of this study demonstrated promising outcomes, including potential energy savings and process streamlining, by identifying crucial design elements for implementing a static mixer in the ballasted flocculation process.

A synthetic and transparent clay removes Microcystis aeruginosa efficiently.

Clay-algae flocculation is a promising method to remove harmful algal blooms (HABs) in aquatic ecosystems. Many HAB-generating species, such as Microcystis aeruginosa (M. aeruginosa), a common species in lakes, produce toxins and harm the environment, human health, and the economy. Natural clays, such as bentonite and kaolinite, and modification of these clays have been applied to mitigate HABs by forming large aggregates and settling down. In this study, we aim to examine the impact of laponite, a commercially available smectite clay that is synthetic, transparent, compatible with human tissues, and degradable, on removing HABs. We compare the cell removal efficiencies (RE) of laponite, two natural clays, and their polyaluminum chloride (PAC)-modified versions through clay-algae flocculation experiments. Our results show that the optimum concentrations of laponite, bentonite, kaolinite, PAC-modified bentonite, and PAC-modified kaolinite to remove 80 % of the M. aeruginosa cells from the water column are 0.05 g/L, 2 g/L, 4 g/L, 2 g/L and 0.3 g/L respectively. Therefore, to achieve the same cell removal efficiency, the amount of laponite needed is 40 to 80 times less than bentonite and kaolinite, and 6 times less than PAC-modified kaolinite. We demonstrate that the superior performance of laponite clay is because of its smaller particle size, which increases the encounter rate between cells and clay particles. Furthermore, experiments using water samples from Powderhorn Lake confirmed laponite's effectiveness in mitigating HABs. Our price analysis also suggests that this commercially-available clay, laponite, can be used in the field at a relatively low cost.

Efficient enrichment of uranium (VI) in aqueous solution using magnesium-aluminum layered double hydroxide composite phosphate-modified hydrothermal biochar: Mechanism and adsorption.

This study presents the successful synthesis of Magnesium-aluminum layered double hydroxide composite phosphate-modified hydrothermal biochar for efficient removal of U(VI) from aqueous solutions. A novel synthesis approach involving phosphate thermal polymerization-hydrothermal method was employed, deviating from conventional pyrolysis methods, to produce hydrothermal biochar. The combination of solvent thermal polymerization technique with hydrothermal process facilitated efficient loading of layered double hydroxide (LDH) components onto the biochar surface, ensuring simplicity, low energy consumption and enhanced modifiability. Bamboo waste was utilized as the precursor for biochar, highlighting its superior green and sustainable characteristics. Additionally, this study elucidated the interactions between phosphate-modified hydrothermal biochar and LDH components with U(VI). Physicochemical analysis demonstrated that the composite biochar possessed a high surface area and abundant oxygen-containing functional groups. XPS and FTIR analyses confirmed the efficient adsorption of U(VI), attributed to chelation interactions between phosphate groups, magnesium hydroxyl groups, hydroxyl groups and U(VI), as well as the co-precipitation of U(VI) with multi-hydroxyl aluminum cations captured by LDH. The composite biochar reached adsorption equilibrium with U(VI) within 80 min and exhibited excellent fitting to the pseudo-second-order kinetic model and Langmuir model. Under conditions of pH = 4 and 298 K, it displayed significantly high maximum adsorption capacity of approximately 388.81 mg g⁻1, surpassing untreated biochar by 17-fold. The adsorption process was found to be endothermic and spontaneous and even after five consecutive adsorption-desorption cycles, the removal efficiency of U(VI) remained stable at 75.46%. These findings underscore the promising application prospects of Magnesium-aluminum layered double hydroxide composite phosphate-modified hydrothermal biochar in efficiently separating U(VI) from uranium-containing wastewater, emphasizing its environmental and economic value.

Aluminum oxyhydroxide-Poly(I:C) combination adjuvant with balanced immunostimulatory potentials for prophylactic vaccines.

The development of high-purity antigens promotes the urgent need of novel adjuvant with the capability to trigger high levels of immune response. Polyinosinic-polycytidylic (Poly(I:C)) is a synthetic double-stranded RNA (dsRNA) that can engage Toll-like receptor 3 (TLR3) to initiate immune responses. However, the Poly(I:C)-induced toxicity and inefficient delivery prevent its applications. In our study, combination adjuvants are formulated by aluminum oxyhydroxide nanorods (AlOOH NRs) and Poly(I:C), named Al-Poly(I:C), and the covalent interaction between the two components is further demonstrated. Al-Poly(I:C) mediates enhanced humoral and cellular immune responses in three antigen models, i.e., HBsAg virus-like particles (VLPs), human papilloma virus (HPV) VLPs and varicella-zoster virus (VZV) glycoprotein E (gE). Further mechanistic studies demonstrate that the dose and molecular weight (MW) of Poly(I:C) determine the physicochemical properties and adjuvanticity of the Al-Poly(I:C) combination adjuvants. Al-Poly(I:C) with higher Poly(I:C) dose promotes antigen-bearing dendritic cells (DCs) recruitment and B cells proliferation in lymph nodes. Al-Poly(I:C) formulated with higher MW Poly(I:C) induces higher activation of helper T cells, B cells, and CTLs. This study demonstrates that Al-Poly(I:C) potentiates the humoral and cellular responses in vaccine formulations. It offers insights for adjuvant design to meet the formulation requirements in both prophylactic and therapeutic vaccines.

Silicon or Calcium Doping Coordinates the Immunostimulatory Effects of Aluminum Oxyhydroxide Nanoadjuvants in Prophylactic Vaccines.

Aluminum salts still remain as the most popular adjuvants in marketed human prophylactic vaccines due to their capability to trigger humoral immune responses with a good safety record. However, insufficient induction of cellular immune responses limits their further applications. In this study, we prepare a library of silicon (Si)- or calcium (Ca)-doped aluminum oxyhydroxide (AlOOH) nanoadjuvants. They exhibit well-controlled physicochemical properties, and the dopants are homogeneously distributed in nanoadjuvants. By using Hepatitis B surface antigen (HBsAg) as the model antigen, doped AlOOH nanoadjuvants mediate higher antigen uptake and promote lysosome escape of HBsAg through lysosomal rupture induced by the dissolution of the dopant in the lysosomes in bone marrow-derived dendritic cells (BMDCs). Additionally, doped nanoadjuvants trigger higher antigen accumulation and immune cell activation in draining lymph nodes. In HBsAg and varicella-zoster virus glycoprotein E (gE) vaccination models, doped nanoadjuvants induce high IgG titer, activations of CD4+ and CD8+ T cells, cytotoxic T lymphocytes, and generations of effector memory T cells. Doping of aluminum salt-based adjuvants with biological safety profiles and immunostimulating capability is a potential strategy to mediate robust humoral and cellular immunity. It potentiates the applications of engineered adjuvants in the development of vaccines with coordinated immune responses.

An application of hierarchical MgAl hydrotalcite in the highly efficient treatment of oilfield macromolecular contaminants.

In this work, salicylic acid (SA) was used to induce the self-assembly of octadecyl trimethyl ammonium chloride (OTAC), a cationic surfactant, into three-dimensional wormlike micelle aggregates. These aggregates act as a soft template for hierarchical MgAl hydrotalcite (LDH) to create a multi-level pore structure adsorption material. Scanning electron microscopy characterization showed that the surface of the hierarchical hydrotalcite exhibited a dense layered structure, unlike the monolayer structure of ordinary hydrotalcite. Furthermore, the hierarchical MgAl-LDH possesses a significantly larger specific surface area (113.94 m2/g) and wide pore size distribution ranging more extensively from 2 to 80 nm, which significantly has an impressive adsorption effect on sulfonated lignite (SL), with a maximum adsorption capacity of 192.7 mg/g at pH = 7. Extensive research has been conducted on the adsorption mechanism of hierarchical MgAl-LDH, attributing it to surface adsorption due to the unique multi-level structure of the adsorbent. After two cycles of regeneration experiments, the adsorption capacity of the adsorbent remained at a high level of 179.1 mg/g, demonstrating the excellent renewability of hierarchical MgAl-LDH. Moreover, the hierarchical hydrotalcite showed high adsorption capacity in the adsorption of sulfonated lignite, which was attributed to its larger specific surface area and superior pore structure to expose more active sites.

Europium insertion into MgAl hydrotalcite-like compound to promote the photocatalytic oxidation of nitrogen oxides.

Easy synthesis of efficient, non-toxic photocatalysts is a target to expand their potential applications. In this research, the role of Eu3+ doping in the non-toxic, affordable, and easily prepared MgAl hydrotalcite-like compounds (HTlcs) was explored in order to prepare visible light semiconductors. Eu doped MgAl-HTlcs (MA-xEu) samples were prepared using a simple coprecipitation method (water, room temperature and atmospheric pressure) and europium was successfully incorporated into MgAl HTlc frameworks at various concentrations, with x (Eu3+/M3+ percentage) ranging from 2 to 15. Due to the higher ionic radius and lower polarizability of Eu3+ cation, its presence in the metal hydroxide layer induces slight structural distortions, which eventually affect the growth of the particles. The specific surface area also increases with the Eu content. Moreover, the presence of Eu3+ 4f energy levels in the electronic structure enables the absorption of visible light in the doped MA-xEu samples and contributes to efficient electron-hole separation. The microstructural and electronic changes induced by the insertion of Eu enable the preparation of visible light MgAl-based HTlcs photocatalysts for air purification purposes. Specifically, the optimal HTlc photocatalyst showed improved NOx removal efficiency, ∼ 51% (UV-Vis) and 39% (visible light irradiation, 420 nm), with excellent selectivity (> 96 %), stability (> 7 h), and enhanced release of •O2- radicals. Such results demonstrate a simple way to design photocatalytic HTlcs suitable for air purification technologies.

Removal of PFAS by hydrotalcite: Adsorption mechanisms, effect of adsorbent aging, and thermal regeneration.

Layered double hydroxides (LDH) have been shown to be effective adsorbents, but their utility for the treatment of per- and polyfluoroalkyl substances (PFAS) in water has not been fully explored. In this study, the adsorption of 9 PFAS on hydrotalcite (HT), a type of LDH, was investigated using reaction solutions with environmentally relevant PFAS concentrations. The adsorption of individual PFAS by HT depended upon a range of factors, including the temperature used to pre-treat (i.e., calcine) the HT, aging conditions, and the presence of anions in the solution. HT calcined near 400 °C most effectively adsorbed PFAS, but its ability to adsorb PFAS was sensitive to storage conditions. The adsorption of CO2 and moisture from air, which likely resulted in the re-intercalation of CO32- into the interlayer regions of HT, was observed to reduce PFAS adsorption and may explain performance loss over time. The adsorption trend among 9 PFAS and the influence on this process by Cl-, NO3-, SO42-, and CO32- indicated that adsorption occurred via a combination of ion exchange, electrostatic attraction, and hydrophobic interactions, although the relative importance of each mechanism deserves further investigation. During this study, we also demonstrated for the first time that HT can be thermally regenerated at 400 °C without affecting its ability to adsorb PFOS and PFBA. Overall, our results suggest that HT may serve as an effective alternative for PFAS treatment.

Optimizing Green Synthesis of Hydrotalcite - Silver Nanoparticles using Syzygium Nervosum based Reducing Agent.

Hydrotalcite-silver (HT-Ag) nanoparticles have been involved in various daily crucial applications, such as antibacterial, photocatalytic, adsorption, etc. There are many approaches to synthesizing silver nanoparticles (AgNPs) decorated on hydrotalcite (HT) surface and the most used approach is using a strong reducing agent. Thus, affordable but effective "green" reducing agents - Syzygium nervosum leaf extract, are taken into account in this work to solve several issues related to chemical reducing agents. This work aimed to assess the effect of Syzygium nervosum leaf extract as a reducing agent for green synthesis of AgNPs on HT through an optimizing process using response surface methodology (RSM) and the Box-Benken model. The optimal conditions for the synthesis of AgNPs on HT include a reaction time of 6.15 hours, a reaction temperature of 50 °C, and the ratio of diluted Syzygium nervosum leaf extract to reduce AgNO3 of 50.37 mL/mg. Under the optimal conditions, the yield of the reduction reaction reached 77.54 %, close to the theoretical value of 76.97 %. The optimization model was suitable for the experiment data. Besides, the morphology, density, and characteristics of AgNPs on the surface of HT layers have been determined by using Ultraviolet-visible spectroscopy, Field emission scanning electron microscopy (FESEM), High-resolution transmission electron microscopy (HR-TEM), selected area diffraction, X-ray diffraction, Dynamic light scattering (DLS), Infrared (IR) spectroscopy, Fluorescence emission spectroscopy (FE), Brunauer-Emmett-Teller (BET) methods. The spherical AgNPs were synthesized successfully on the surface of HT with the average particle size of 13.0±1.1 nm. Interestingly, HT-Ag hybrid materials can inhibit strongly the growth of E. coli, S. aureus as well as two antibiotic resistance bacterial strains, P. stutzeri B27, and antibiotic resistance E. coli. Especially, the antibacterial activity quantification and durability of the HT-Ag hybrid materials were also tested. Overall, the HT-Ag hybrid materials are very promising for application in material science and biomedicine fields.

The use of coagulant and natural soil to control cyanobacterial blooms in a tropical reservoir.

Cyanobacterial blooms have been a growing problem in water bodies and attracted attention from researcher and water companies worldwide. Different treatment methods have been researched and applied either inside water treatment plants or directly into reservoirs. We tested a combination of coagulants, polyaluminium chloride (PAC) and iron(III) chloride (FeCl3), and ballasts, luvisol (LUV) and planosol (PLAN), known as the 'Floc and Sink' technique, to remove positively buoyant cyanobacteria from a tropical reservoir water. Response Surface Methodology (RSM) based on Central Composite Design (CCD) was used to optimize the two reaction variables - coagulant dosage (x1) and ballast dosage (x2) to remove the response variables: chlorophyll-a, turbidity, true color, and organic matter. Results showed that the combination of LUV with PAC effectively reduced the concentration of the response variables, while PLAN was ineffective in removing cyanobacteria when combined to PAC or FeCl3. Furthermore, FeCl3 presented poorer floc formation and lower removal efficiency compared to PAC. This study may contribute to the theoretical and practical knowledge of the algal biomass removal for mitigating eutrophication trough different dosages of coagulants and ballasts.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

Purpose: The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. Methods: MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Results: Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. Conclusion: This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

Lanthanum-modified pyroaurite as a geoengineering tool to simultaneously sink Microcystis cyanobacteria and immobilize phosphorus in eutrophic water.

Excessive phosphorus (P) in eutrophic water induces cyanobacterial blooms that aggravate the burden of in-situ remediation measures. In order to ensure better ecological recovery, Flock & Lock technique has been developed to simultaneously sink cyanobacteria and immobilize P but requires a combination of flocculent and P inactivation agent. Here we synthesized a novel lanthanum-modified pyroaurite (LMP), as an alternative for Flock & Lock of cyanobacteria and phosphorus at the background of rich humic acid and suspended solids. LMP shows a P adsorption capacity of 36.0 mg/g and nearly 100 % removal of chlorophyll-a (Chl-a), turbidity, UV254 and P at a dosage (0.3 g/L) much lower than the commercial analogue (0.5 g/L). The resultant sediment (98.2 % as immobile P) exhibits sound stability without observable release of P or re-growth of cyanobacteria over a 50-day incubation period. The use of LMP also constrains the release of toxic microcystins to 1.4 µg/L from the sunk cyanobacterial cells, outperforming the commonly used polyaluminum chloride (PAC). Similar Flock & Lock efficiency could also be achieved in real eutrophic water. The outstanding Flock & Lock performance of LMP is attributable to the designed La modification. During LMP treatment, La acts as not only a P binder by formation of LaPO4, but also a coagulant to create a synergistic effect with pyroaurite. The controlled hydrolysis of surface La(III) over pyroaurite aided the possible formation of La(III)-pyroaurite networking structure, which significantly enhanced the Flock & Lock process through adsorption, charge neutralization, sweep flocculation and entrapment. In the end, the preliminary economic analysis is performed. The results demonstrate that LMP is a versatile and cost-effective agent for in-situ remediation of eutrophic waters.

Suitability of inorganic coagulants for algae-laden water treatment: Trade-off between algae removal and cell viability, aggregate properties and coagulant residue.

Inorganic coagulants could effectively precipitate algae cells but might increase the potential risks of cell damage and coagulant residue. This study was conducted to critically investigate the suitability of polyaluminum (PAC), FeCl3 and TiCl4 for algae-laden water treatment in terms of the trade-off between algal substance removal, cell viability, and coagulant residue. The results showed that an appropriate increase in coagulant dosage contributed to better coagulation performance but severe cell damage and a higher risk of intracellular organic matter (IOM) release. TiCl4 was the most destructive, resulting in 60.85% of the algal cells presenting membrane damage after coagulation. Intense hydrolysis reaction of Ti salts was favorable for the formation of larger and more elongated, dendritic structured flocs than Al and Fe coagulants. TiCl4 exhibited the lowest residue level and remained in the effluents mainly in colloidal form. The study also identified charge neutralization, chemisorption, enmeshment, and complexation as the dominant mechanisms for algae water coagulation by metal coagulants. Overall, this study provides the trade-off analyses between maximizing algae substance removal and minimizing potential damage to cell integrity and is practically valuable to develop the most suitable and feasible technique for algae-laden water treatment.

The orientation of CpG conjugation on aluminum oxyhydroxide nanoparticles determines the immunostimulatory effects of combination adjuvants.

In subunit vaccines, aluminum salts (Alum) are commonly used as adjuvants, but with limited cellular immune responses. To overcome this limitation, CpG oligodeoxynucleotides (ODNs) have been used in combination with Alum. However, current combined usage of Alum and CpG is limited to linear mixtures, and the underlying interaction mechanism between CpG and Alum is not well understood. Thus, we propose to chemically conjugate Alum nanoparticles and CpG (with 5' or 3' end exposed) to design combination adjuvants. Our study demonstrates that compared to the 3'-end exposure, the 5'-end exposure of CpG in combination adjuvants (Al-CpG-5') enhances the activation of bone-marrow derived dendritic cells (BMDCs) and promotes Th1 and Th2 cytokine secretion. We used the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen (HBsAg) as model antigens to demonstrate that Al-CpG-5' enhanced antigen-specific antibody production and upregulated cytotoxic T lymphocyte markers. Additionally, Al-CpG-5' allows for coordinated adaptive immune responses even at lower doses of both CpG ODNs and HBsAg antigens, and enhances lymph node transport of antigens and activation of dendritic cells, promoting Tfh cell differentiation and B cell activation. Our novel Alum-CPG strategy points the way towards broadening the use of nanoadjuvants for both prophylactic and therapeutic vaccines.

Ion-imprinted macroporous polyethyleneimine incorporated chitosan/layered hydrotalcite foams for the selective biosorption of U(VI) ions.

In order to prevent uranium pollution and recovery uranium resources, it was necessary to find a highly efficient adsorbent for radioactive wastewater treatment. Herein, U(VI) imprinted polyethyleneimine (PEI) incorporated chitosan/layered hydrotalcite composite foam (IPCL) was synthesized by combining ion-imprinting and freeze-drying techniques. IPCL has a high amino/imino content and an ultralight macroporous structure, making it capable of efficiently adsorbing U(VI) and easy to separate; Especially after ion-imprinting, vacancies matching the size of uranyl ions were formed, significantly improving U(VI) selectivity. The adsorption isotherms and adsorption kinetics were in accordance with the Freundlich model and PSO model respectively, indicating that heterogeneous adsorption of U(VI) by the adsorbents. The adsorption capacity of IPCL-2 for U(VI) reached 278.8. mg/g (under the conditions of optimal pH 5.0, temperature of 298 K, contact time of 2 h, and adsorbent dosage of 0.2 g/L), which is almost double of that for the non-imprinted foam (PCL-2, 138.2 mg/g), indicating that IPCL-2 can intelligently recognize U(VI). The heterogeneous adsorption mechanism of U(VI) by IPCL-2 involves complexation, ion-exchange and isomorphic substitution. The adsorption of U(VI) by IPCL-2 is spontaneous and endothermic. IPCL-2 has excellent adsorption performance for U(VI), and is a promising adsorbent for radioactive pollution control.