Strong Acid Resistance Research Articles

Ionically assembled hemostatic powders with rapid self-gelation, strong acid resistance, and on-demand removability for upper gastrointestinal bleeding.

Upper gastrointestinal bleeding (UGIB) is bleeding in the upper part of the gastrointestinal tract with an acidic and dynamic environment that limits the application of conventional hemostatic materials. This study focuses on the development of N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride/phytic acid (HTCC/PA, HP) powders with fast hemostatic capability and strong acid resistance, for potential applications in managing UGIB. Upon contact with liquids within 5 seconds, HP powders rapidly transform into hydrogels, forming ionic networks through electrostatic interactions. The ionic crosslinking process facilitates the HP powders with high blood absorption (3.4 times of self-weight), sufficient tissue adhesion (5.2 and 6.1 kPa on porcine skin and stomach, respectively), and hemostasis (within 15 seconds for in vitro clotting). Interestingly, the PA imparts the HP powders with strong acid resistance (69.8% mass remaining after 10 days of incubation at pH 1) and on-demand removable sealing while HTCC contributes to fast hemostasis and good wet adhesion. Moreover, the HP powders show good biocompatibility and promote wound healing. Therefore, these characteristics highlight the promising clinical potential of HP powders for effectively managing UGIB.

On-site visual sensing of antibiotics in food by new fluorescent lanthanide metal–organic frameworks

In recent years, foods that contaminated by the antibiotics is a serious threat to human health, so, the on-site visual detection of antibiotics in food is crucial. In this work, two new two-dimensional lanthanide metal–organic frameworks (2D LnMOFs) are synthesized by mild hydrothermal method and detailly characterized by single crystal structure analysis, photophysics, thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD), FT-IR spectra. Results show the two LnMOFs has high thermo-stability, strong acid and alkaline resistance. Further studies reveal that TbMOF is a highly sensitive and selective fluorescent probe for the antibiotics of enrofloxacin (Enr) and ciprofloxacin (Cip), with a very short response time of 15 s. The limits of detection (LODs) for Enr and Cip are very low values of 190 and 70 nM, respectively, based on the method of 3σ/K, which is lower than the national food safety standard (GB 31650–2019). In addition, portable test paper based on TbMOF is fabricated, which realized the visible and on-site detection of Enr and Cip in the real samples of egg and milk.

Pig-Derived Probiotic Bacillus tequilensis YB-2 Alleviates Intestinal Inflammation and Intestinal Barrier Damage in Colitis Mice by Suppressing the TLR4/NF-κB Signaling Pathway.

The search for new probiotics has been regarded as an important approach to improving intestinal health in animals. Bacillus has many advantages, such as strong resistance to harmful external factors, wide distribution, and easy colonization of the intestine. Hence, this study aims to screen for a probiotic Bacillus strain that improves animal intestinal health and to elucidate its probiotic mechanism so as to provide probiotic resources for the development of feed-using probiotic formulations. In this research, a strain of Bacillus was isolated from adult pig feces and named B. tequilensis YB-2. In vitro probiotic experiments showed that B. tequilensis YB-2 had strong acid and bile salt resistance, indicating that this strain can customize in the intestine. To further explore the effect of B. tequilensis YB-2 upon animal intestinal health, DSS-induced murine colitis models were established, and the body weight, colonic morphology, inflammatory cytokines level, and intestinal-barrier- and TLR4/NF-κB-pathway-related protein were determined. The results showed that mice receiving drinking water with 3% DSS were found to develop colitis symptoms, including body weight loss and increased disease activity index (DAI); colon length and microvilli shedding were shortened; tight junctions were disrupted; goblet cells decreased; anti-inflammatory cytokines were inhibited; and pro-inflammatory cytokines and the TLR4/NF-κB signaling pathway were activated. Notably, orally received B. tequilensis YB-2 alleviated symptoms of DSS-induced colitis in mice. The above results indicated that B. tequilensis YB-2 was capable of improving colitis in mice by weakening inflammation and intestinal barrier damage, and its mechanism may involve the TLR4/NF-κB pathway. Overall, this research suggests that B. tequilensis YB-2 has the potential to serve as an animal feed additive to prevent intestinal inflammation.

In situ growth of HKUST-1 on electrospun polyacrylonitrile nanofibers/regenerated cellulose aerogel for efficient methylene blue adsorption

Dyes, as organic pollutants, are causing increasingly severe environmental problems. Metal-organic frameworks (MOFs) are considered promising dye adsorbents; however, their application is limited due to their powder or solid particle forms and limited reusability. Therefore, this study proposes an innovative approach to develop a novel MOF-based composite aerogel, specifically a HKUST-1/polyacrylonitrile nanofibers/regenerated cellulose (HKUST-1/PANNs/RC) composite aerogel adsorbent, for the adsorption of pollutants in water. This adsorbent was successfully prepared using a simple method combining covalent crosslinking, quick freezing, freeze-drying, in-situ growth synthesis, and solvothermal techniques. The HKUST-1/PANNs/RC composite aerogel exhibits a significantly large specific surface area, which is approximately 64 times greater than that of PANNs/RC (10.45 m2·g−1), with a specific surface area of 669.9 m2·g−1. The PANNs serve as a support framework, imparting excellent mechanical properties to the composite aerogel, enhancing its overall stability and recoverability. Additionally, the composite aerogel contains numerous -COOH and -OH groups on its surface, providing strong acid resistance and facilitating interactions with pollutant molecules through electrostatic interactions, π-π conjugation, n-π* interactions, and hydrogen bonding, thereby promoting the adsorption process. Using methylene blue (MB) as a probe molecule, the study results demonstrate that the HKUST-1/PANNs/RC composite aerogel has an adsorption capacity of 522.01 mg·g−1 for MB (25 h), exhibiting excellent adsorption performance. This composite aerogel shows great potential for application in water pollution control.

Multidimensional nanochannel design and regulation of ultra-thin GOQDs-AGQDs composite membranes

Graphene-based composite membranes with long and tortuous transport paths restricted its efficient and wide application in substance separation and purification field. In this study, we propose a multidimensional mass-transfer channel construction method for fabricating highly permeable 2D laminar membranes with lots of stable molecular transport channels. In particular, a robust GOQDs-AGQDs composite membranes with adjustable interlayer sieving channels were prepared based on vacuum assisted self-assembly by intercalating AGQDs with average size of 7.5 nm between GOQDs with average size of 34.0 nm, which presented highly permeability with plentiful nano-channels in both vertical and horizontal directions. As the mass fraction of doped AGQDs reached to 60 wt%, the best performance of GOQDs-AGQDs composite membranes was obtained, with a functional layer thickness of 24.1 nm, good stability, and strong acid and alkali resistance. The usage of small diameter GOQDs with intercalating smaller diameter AGQDs extremely shortened the transfer channel path and slightly increased the interlayer spacing (8.26 to 8.75 Å), which dramatically improved its permeation flux of 14 times higher than that of the pure GO membrane with similar dye rejection, and reached to 133.3 L·m−2·h−1 under 2 bar at the optimized condition. This study provided insights into self-assembling small-sized 2D nanomaterials into membranes and fine-tuning their nanochannel structure.

Facile fabrication of fluorine-free waterproof and breathable nanofiber membranes with UV-resistant and acid-alkali resistant performances

Membranes with good waterproofness and breathability are desired for the preparation of outdoor sports garments. However, current waterproof and breathable membranes use environmentally hazardous fluorine-containing raw materials and suffer from many problems such as complicated preparation processes and single function. Therefore, it is a great challenge to select environmentally friendly raw materials to prepare multi-functional membranes with waterproof-breathable performance by simple preparation method. In this paper, fluorine-free poly(styrene-b-butadiene-b-styrene) (SBS), polyurethane (PU), and 2-hydroxy-4-n-octyloxy benzophenone (UV531) were selected to prepare multi-functional nanofiber membranes by convenient one-step electrospinning. The properties of the environmentally friendly multi-functional SBS/PU/UV531 nanofiber membranes were systematically optimized by adjusting the concentration of UV531 in the nanofiber membranes. The ultimately obtained multi-functional SBS/PU/UV531–2 nanofiber membrane shows excellent waterproofness (hydrostatic pressure: 58.8 kPa), high breathability (WVT rate: 5.2 kg m−2 d−1), good mechanical properties (breaking strength: 7.26 MPa, breaking elongation: 327.9%), excellent UV resistance (UPF: 238.23), and strong acid and alkali resistance properties. This multi-functional nanofiber membrane has broad application prospects in a variety of fields such as outdoor protective clothing, extreme environment materials, and military products.

Adsorption and recovery of Cr(vi) from wastewater by Chitosan–Urushiol composite nanofiber membrane

Abstract Chitosan (CS) is widely used in the treatment of wastewater containing metal ions. However, the poor stability in acidic aqueous solutions severely limits its application in many practical scenarios. In this work, a CS-based composite nanofiber membrane was prepared by electrospinning using urushiol, a natural biomaterial, as the cross-linking agent. The application of the CS-urushiol (CS-U) membrane in the adsorption and recovery of Cr(vi) in wastewater was systematically studied. The CS-U membrane showed great resistance to strongly acidic and oxidative environments, and the adsorption process combined two mechanisms of electrostatic attraction and redox reaction. Due to the nanoscale fibers, porous structure, and strong acid resistance, the CS-U membrane adsorbed Cr(vi) rapidly and efficiently in both batch and continuous modes. Moreover, the adsorption capacity and selectivity of the CS-U membrane for Cr(vi) could be maximized simultaneously by adjusting the solution pH, promoting the recovery of high-purity Cr2O3.

A novel blending nanofibrous membrane of Poly(ionic liquid) for efficient and fast adsorption of ReO4−

Efficient recovery of rare scattered metal Re(VII) from various resources is a prerequisite due to its important application. Herein, a type of novel nanofibrous membrane, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU, is successfully prepared by electrospinning, where poly(ionic liquid) P(Ph-3MVIm-Br) is incorporated and could supply more adsorption sites. Meanwhile, PVP (polyvinyl pyrrolidone) and TPU (thermoplastic polyurethane) ensured the water flux and the structural stability of the membrane. The nanofibrous membrane exhibited a high adsorption capacity for ReO4−, which can reach 128 mg g−1 at pH 5. Its water flux is as high as 433 L m−2 h−1 at 0.4 g of poly(ionic liquid) addition, membrane thickness of 20 μm, and pressure of 1 bar. Furthermore, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU nanofibrous membrane can remove 91.7% of ReO4− within 30 min. After 9 times recycling, the adsorption efficiency of the membrane can still maintain more than 90%. Dynamic ReO4− removal with 0.4P(Ph-3MVIm-Br)-3PVP/2TPU after one cycle was accomplished with a breakthrough volume of 24 mL ReO4− solution (feed 10 mg L−1, 100 mg membrane). The exchange of ReO4− and Br− of poly(ionic liquid) mostly promote the adsorption of ReO4−. Moreover, the structure of the membrane has excellent selectivity, mechanical performance, strong acid and alkali resistance stability, which endow the membrane easy to operate in practical applications.

Study on iodine adsorption capacity and adsorption mechanism of AgY

ABSTRACT To systematically study the methyl iodide (CH3I) adsorption performance and adsorption mechanism of Ag ion exchange NaY zeolite (AgY), AgY adsorbents with different Ag content were selected. 16.6% AgY was capable of storing 150 mg/g and 275 mg/g of CH3I when the penetrated CH3I reached 1‰ and 100% inlet concentration. TEM and EDS results presented a high relationship between Ag dispersion and CH3I adsorption capability. The formation of a stable AgI complex rationalized the CH3I adsorption mechanism on AgY. Compared to AgX, AgY was verified to possess a strong acid resistance by FT-IR, SEM and XRD. The effect of three key parameters (temperature, humidity and gas velocity) on CH3I adsorption was carefully investigated by orthogonal experiment design. The experimental results showed that AgY had better iodine removal performance at a high temperature, low humidity, and low flow rate. This work provides technical reference for further engineering applications of 16.6%AgY in spent fuel reprocessing plants.

Structural modification of photochromic microcapsule shell to enhance acid resistance

Enhancement of weather fastness and acid resistance of photochromic (PC) materials when exposed to outdoor actual weather conditions is crucial for practical application. In this paper, by introducing amine and ether bonding groups, we have developed a typical composite structure shell with strong acid resistance, high sealing capacity and good fatigue resistance, then further self-assembled and embedded photo-transformation powder. The acid resistance, photochromic response, fatigue resistance and thermal stability of fabricated photochromic microcapsule were investigated systematically. Not only the obtained end products exhibited excellent photochromic ability, also the retention of absorption reached 95.97% under 100 times cycles of visible light irradiation (λ>420 nm) and ultraviolet light irradiation (λ<400 nm), uninterruptedly. Here, we prepare stabilized photochromic microcapsules utilizing polyetheramine (PEA) modified melamine formaldehyde (MF) as shell material for further application in the field of UV indication in extreme environments such as viscose fiber spinning.

Comparative Study of Starch-Based Bioplastic from Banana (Musa acuminata) peel (SBB) Incorporated with Commercialized and Extracted Chitin

Abstract: The study produced extracted Chitin from Asian Green Mussel (Perna viridis) and Golden Apple Snail (Pomacea canaliculate) shells using two-way chemical extraction process; deproteinization and demineralization. The extracted and commercialized Chitin were characterized through Fourier Transform Infrared (FTIR) Spectroscopy to determine and compare the functional groups present. Starch-based bioplastics were produced using banana peel starch (BPS) incorporated with commercialized chitin and chosen chitin extract which is from AGM. The bioplastics were tested for its morphology through Scanning Electron Microscopy (SEM), physical property through air test, chemical properties through biodegradability test, chemical reactivity test, water vapor transmission rate (WVTR) test, water absorption test and flammability test, and mechanical property through tensile strength test. Four treatments were carried out using 1%, 2%, 3%, and 4% by weight chitin addition. The control SBB does not contain any chitin. All treatments were prepared using constant amount of BPS, PVA solution and glycerol. Based from the results, chitin addition improves the strong acid resistance, water-barrier properties, and tensile strength of the SBB. It was found out that the best treatment was T3 of AGM which has a WVTR of 73.9868 g/m2 , dissolved in water in an average of 6.1783 days, and has a tensile strength of 64286.3777 Pa

High‐performance vitrimer films containing acylhydrazone dynamic covalent bonds

AbstractVitrimer films containing acylhydrazone bonds are synthesized in two steps. Bio‐based vanillin and adipate dihydrazide are used to prepare diols containing acylhydrazone bonds in one step, which are introduced into the reaction system of vitrimer to obtain the final films. The process is concise and easy to operate. By utilizing the rigid structure of vitrimer films and introducing dynamic acylhydrazone bonds, the obtained vitrimer films exhibit strong mechanical strength (maximum tensile strength of 27.10 MPa and maintaining up to 185.52% of the original breaking strength), excellent self‐healing property (tensile strength of 26.26 MPa after 12 h of primary self‐healing and 5.24 MPa after 12 h of secondary self‐healing), and rapid shape memory property (recovery time of about 2 min), strong acid and alkali resistance (not dissolved within 24 h), good thermal stability (no decomposition occurs below 160 °C), and high storage modulus (reaches 1087 MPa). These comprehensive benefits yield a certain reference for the preparation of vitrimer materials with prime properties.

Effects of Clostridium butyricum on Intestinal Microflora and Metabolism of Eriocheir sinensis.

Clostridium butyricum, a new probiotic in recent years, can produce butyric acid and short-chain fatty acids. It has the characteristics of strong acid and alkali resistance, high temperature resistance, and strong resistance to most antibiotics, and has more advantages than other probiotics. However, the action mechanism of C. butyricum on Eriocheir sinensis is still unclear and needs further study. In this study, when C. butyricum was added to the basic diet, the number of living bacteria was 0, 1 × 106 and 1 × 108 CFU/g, respectively. The E. sinensis were randomly divided into three groups: (blank control group, experimental group 1 (1 × 106 CFU/g) and experimental group 2 (1 × 108 CFU/g)). They were fed an experimental diet for 28 days. The effects of C. butyricum on E. sinensis were studied by detecting the differences in non-specific immune indexes, intestinal microflora, and metabolites between serum and hepatopancreas. The results showed that C. butyricum could improve the antioxidant ability of E. sinensis serum and hepatopancreas, protect intestinal tissues, and promote the absorption of nutrients. At the same time, it can enhance the microbial diversity and richness of the E. sinensis gut flora. LC-MS metabolomics was used to detect the metabolism of intestinal flora. It was found that C. butyricum could up-regulate lysophosphatidylcholine in the intestine. Through the KEGG enrichment pathway, it was found that significantly different metabolites were mainly concentrated in six metabolic pathways. The purine metabolism and alanine, aspartate, and glutamate metabolism pathways showed a downward trend, indicating that the addition of C. butyricum to feed could reduce purine metabolism, promote the water-salt balance of the organism's cells, and reduce inflammation. In this study, it was found that the addition of certain concentrations of C. butyricum to feed could improve the antioxidant ability of E. sinensis, improve the intestinal flora environment, and promote the growth of beneficial bacteria in the gut. This can promote the body's metabolism, which is more conducive to its growth.

Low-temperature hydrothermal growth of MoS2 nanostructures on carbon foam for hydrogen evolution reaction

The high energy density of hydrogen as a non-pollutant energy resource has attracted more attention as a promising alternative to fossil fuels which cause global pollution and planet warming. While noble metals are employed as electrochemical catalysts in the electrolysis of water to produce hydrogen, their high cost and limited availability prevent them from being used on a larger scale. Due to its good electrochemical activity, strong acid resistance, and affordable price, two-dimensional molybdenum disulfide (2D-MoS2) is introduced as the hydrogen evolution reaction (HER) catalyst. For tackling the low electrical conductivity and low active sites of MoS2, carbon-based materials have been used as high electrical conductive supports to accommodate the well-distributed MoS2 nanostructures to exposure of the higher active sites to the water molecules. In this study, the low-cost carbon foam/MoS2 (CF/MoS2) composites were hydrothermally synthesized at low temperatures (200 °C) as an economical hydrogen generation catalyst. Furthermore, the effects of sulfur precursors are investigated on the morphology, structure, crystallinity, and HER activity by using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The CF/MoS2 composites derived from sulfur, thiourea, thioacetamide, and sodium sulfide, display the 1T/2H crystalline phase. The sulfur-derived CF/MoS2 delivers the best HER activity with the low overpotential of 217 mV at the current density of 10 mA cm−2 and Tafel slope of 112 mV dec−1.

Multi-step screening of suitable Saccharomyces cerevisiae strain for lemon wine brewing

Currently, most fruit wines are fermented with commercial wine yeasts or universal Saccharomyces cerevisiae strains, which leads to the problems of thin taste, insufficient flavor, and lack of typicality of fruit wine. In this study, one S. cerevisiae strain (NM-8) was isolated from the spontaneous fermentation broth of lemon, and its fermentation characteristics for lemon wine were compared with three commercial S. cerevisiae strains. The results showed that S. cerevisiae NM-8 displayed a good acidity tolerance under pH 3.2 and 2.8, which reached the maximum cell value during lemon wine fermentation. In addition, the lemon wine sample fermented with NM-8 contained more ascorbic acid (48.22 mg/L), sorbitol (0.96 g/L), and glycerin (4.44 g/L), which performed positive effects on the smoothness and sweetness of lemon wine. Moreover, both its total flavonoid content and DPPH radical scavenging activity were the highest, which were 320.72 mg RE/L (expressed as rutin equivalent) and 66.33%, respectively. Meanwhile, Gas Chromatography-Mass Spectrometry, Gas Chromatography-Ion Mobility Spectrometry, and sensory evaluation were used for the comprehensive analysis of the flavor compounds of four lemon wines. It showed that the lemon wine fermented with NM-8 had the highest sensory score, possibly due to the abundance of flavor compounds and their higher odor activity value. In conclusion, the screened strain S. cerevisiae NM-8 isolated from lemon surroundings with stronger acid resistance was able to brew excellent lemon wine with not only higher taste evaluation score but also stronger antioxidant activity, indicating that NM-8 showed substantial advantages in producing lemon wine.

Polyethylenimine functionalized sulfur-containing POSS-based dendritic adsorbent for highly efficient and selective capturing of precious metal ions

A novel branched polyethylenimine (PEI) functionalized sulfur-containing polyhedral oligomeric silsesquioxane (POSS)-based dendritic adsorbent (POSS-S-PEI) has been synthesized for the highly proficient and selective capturing of precious metal ions such as platinum (Pt(IV)) and palladium (Pd(II)). The developed POSS-S-PEI exhibits not only highly proficient uptakes of 589.4 ± 23.9 mg/g for Pd(II) and 548.8 ± 19.6 mg/g for Pt(IV), but also high selectivity for these precious metal ions in the mixture of common, coexisting, and heavy metal ions, at pH 1. The adsorption studies accord with the Langmuir isotherm, and pseudo-second-order as well as intraparticle diffusion kinetic models. The uptakes of these precious metal ions were spontaneous and endothermic in nature. The electrostatic interaction, H-bonding, and chelation, between the protonated primary, secondary, and tertiary amino groups as well as the electron donor atoms (O-, S-, and N-) of POSS-S-PEI and these precious metal ions, are crucial factors during the adsorption process. The developed POSS-S-PEI not only exhibits a strong acid-resistance in very low pH, but also demonstrates outstanding reusability for these precious metal ions after five sorption cycles. This work clarifies the potential of POSS-S-PEI that can selectively eliminate precious metal ions from low pH medium, would be significant for the practical application in industry.

One-step conversion of acidified oil to biodiesel by novel bifunctional SrZr1-xFexO3 catalyst

The novel heterogeneous catalysts of SrZr1-xFexO3 (x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30 or 0.40) with acid-base bifunctional property are prepared through the sol-gel method and applied in catalyzing transesterification and esterification from acidified oil to produce biodiesel. The substitution of Zr by Fe in the SrZrO3 perovskite results in the lattice distortion to generate abundant surface oxygen vacancies. Also, the enhancement of electron density on active sites improves the acidity and basicity of catalyst to construct the acid-base pair sites for high efficiency of biodiesel production. The SrZr0.75Fe0.25O3 catalyst shows the strongest catalytic activity and the maximum FAME yield of 99.5% is achieved at the reaction temperature of 178 °C, catalyst amount of 4.5 wt%, methanol to oil molar ratio of 19:1 and reaction duration of 3.4 h through optimizing reaction parameters by convolutional neural network. The catalyst exhibits strong acid resistance and the FAME yield of 93.9% is achieved with 30 wt% oleic acid addition, where methanol is readily adsorbed to Sr site for transesterification and free fatty acids are readily adsorbed to Fe site for esterification. In addition, the SrZr0.75Fe0.25O3 catalyst shows satisfactory reusability and the FAME yield of 96.2% is maintained for the fifth reused cycle.

Functionalized waterworks sludge particles as column packing materials for simultaneous Cr (Ⅵ) removal and oil separation

Highly efficient and low-cost treatment of waterworks sludge and oil-containing Cr (Ⅵ) wastewater in one way is a challenge in the field of water treatment. Herein, a waste-control-waste strategy was proposed to fabricate a functionalized waterworks sludge-based Zn–Al layer double oxides material (Zn–Al LDOs/WS) for simultaneously separating Cr (Ⅵ) and oil. During the column separation process, due to the superhydrophilic/underwater superoleophobicity of Zn–Al LDOs/WS and the memory effect of LDHs, Cr (Ⅵ) will be stabled in the filter layer by electrostatic attraction and surface complexation between the Zn–Al LDHs/WS and Cr (Ⅵ), and the small oil droplets will coalesce into big oil droplets that be blocked in the separation column, thus achieving simultaneous separation. The Zn–Al LDOs/WS with hierarchical porous structure exhibit excellent simultaneous separation efficiency for Cr (Ⅵ) (99.69%) and oil (99.24%), and high separation flux (1063 L m−2 h−1). In addition, the separation efficiency and flux can be flexibly controlled by adjusting the filter layer thickness. The Zn–Al LDOs/WS also display strong acid and alkali resistance (pH 1–11), wide applicability range of initial Cr (Ⅵ) concentration (5–200 mg/L) and outstanding anti-interfering ion ability (Cl−, HCO3−, SO42−, NO3−, H2PO4−, CO32− and F−) in Cr (Ⅵ) and oil separation. Therefore, this work can not only improve treatment efficiency and save costs through simultaneous separation, effectively treat solid waste and complex wastewater, but also provide a theoretical basis for the design and application of functional materials derived from waste sludge.

Cd2 Nb2 Te4 O15 : A Novel Pseudo-Aurivillius-Type Tellurite with Unprecedented Nonlinear Optical Properties and Excellent Stability.

Oxides are emerging candidates for mid-infrared (mid-IR) nonlinear optical (NLO) materials. However, their intrinsically weak second harmonic generation (SHG) effects hinder their further development. A major design challenge is to increase the nonlinear coefficient while maintaining the broad mid-IR transmission and high laser-induced damage threshold (LIDT) of the oxides. In this study, it is reported on a polar NLO tellurite, Cd2 Nb2 Te4 O15 (CNTO), featuring a pseudo-Aurivillius-type perovskite layered structure composed of three types of NLO active groups, including CdO6 octahedra, NbO6 octahedra, and TeO4 seesaws. The uniform orientation of the distorted units induces a giant SHG response that is ≈31 times larger than that of KH2 PO4 , the largest value among all reported metal tellurites. Additionally, CNTO exhibits a large band gap (3.75eV), a wide optical transparency window (0.33-14.5µm), superior birefringence (0.12@ 546nm), high LIDT (23×AgGaS2 ), and strong acid and alkali resistance, indicating its potential as a promising mid-IR NLO material.

Effective removal of Mn(Ⅱ) from acidic wastewater using a novel acid tolerant fungi Aspergillus sp. MF1 via immobilization

Biological processes based on the oxidation of Mn(II) are extensively favored. However, this is always limited by the low pH of wastewater. The biological removal of Mn(II) from acidic wastewater through immobilization technology is a promising approach owing to its high efficiency and low cost. However, the mechanism underlying Mn(II) removal by fungi remains unclear. In this study, a strain of acid-tolerant Aspergillus sp. MF1 screened from acid mine drainage (AMD), was used for immobilization. The results showed that polyvinyl alcohol (PVA), sodium alginate (SA), and zeolite were the best carrier materials, and the contents of CaCl2, PVA, SA, zeolite, and spore suspension were 4%, 6%, 2%, 4%, and 15%, respectively. The maximum Mn(II) removal efficiency achieved was 77.21%. Additionally, the analysis of subcellular distribution and chemical morphology demonstrated that Mn(II) removal was attributed to intracellular enrichment. The microspheres were reused for three cycles, and the removal efficiency of Mn(II) was guaranteed to exceed 60%. In summary, the immobilized Aspergillus sp. MF1 has stronger acid resistance and more effective treatment efficiency under high concentrations of Mn(II) compared to traditional biological processes, illustrating the excellent application prospects for Mn(II)-containing acidic wastewater.