scholarly journals Effective Removal of Calcium and Magnesium Ions from Water by a Novel Alginate–Citrate Composite Aerogel

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 125
Author(s):  
Zhuqing Wang ◽  
Zhongmin Feng ◽  
Leilei Yang ◽  
Min Wang
Keyword(s):  
Freeze Drying ◽  
Adsorption Mechanism ◽  
Drying Method ◽  
Composite Aerogel ◽  
Adsorption Capacities ◽  
Effective Removal ◽  
Chemical Grafting ◽  
Coordination Effect ◽  
Repeated Use ◽  
Calcium And Magnesium Ions

In this work, a novel alginate/citrate composite aerogel (CA–SC) was synthesized by chemical grafting technology combined with vacuum freeze-drying method, and CA–SC was used for removing calcium (Ca2+) and magnesium (Mg2+) ions from water. The experimental results indicate that the as-prepared CA–SC has a high affinity for Ca2+ and Mg2+ and can remove 96.5% of Ca2+ (or 96.8% of Mg2+) from the corresponding solution. The maximum adsorption capacities of CA–SC for Ca2+ and Mg2+ are 62.38 and 36.23 mg/g, respectively. These values are higher than those of the most reported Ca2+-sorbents and Mg2+-sorbents. The CA–SC adsorbent can be regenerated through a simple pickling step, and its adsorption performance keeps stable after repeated use. Analysis of the adsorption mechanism shows that the CA–SC combines Ca2+ and Mg2+ in water mainly through coordination effect.

scholarly journals Simple Urea Immersion Enhanced Removal of Tetracycline from Water by Polystyrene Microspheres

2018 ◽  
Vol 15 (7) ◽  
pp. 1524
Author(s):  
Junjun Ma ◽  
Bing Li ◽  
Lincheng Zhou ◽  
Yin Zhu ◽  
Ji Li ◽  
...  
Keyword(s):  
Surface Modification ◽  
Adsorption Mechanism ◽  
Water Environment ◽  
Order Rate Constant ◽  
Maximum Adsorption Capacity ◽  
Polystyrene Microspheres ◽  
Multilayer Adsorption ◽  
First Order ◽  
Adsorption Capacities ◽  
Effective Removal

Antibiotics pose potential ecological risks in the water environment, necessitating their effective removal by reliable technologies. Adsorption is a conventional process to remove such chemicals from water without byproducts. However, finding cheap adsorbents with satisfactory performance is still a challenge. In this study, polystyrene microspheres (PSM) were enhanced to adsorb tetracycline by surface modification. Simple urea immersion was used to prepare urea-immersed PSM (UPSM), of which surface groups were characterized by instruments to confirm the effect of immersion. Tetracycline hydrochloride (TC) and doxycycline (DC) were used as typical adsorbates. The adsorptive isotherms were interpreted by Langmuir, Freundlich, and Tempkin models. After urea immersion, the maximum adsorption capacity of UPSM at 293 K and pH 6.8 increased about 30% and 60%, achieving 460 mg/g for TC and 430 mg/g for DC. The kinetic data were fitted by first-order and second-order kinetics and Weber–Morris models. The first-order rate constant for TC adsorption on UPSM was 0.41 /h, and for DC was 0.33 /h. The cyclic urea immersion enabled multilayer adsorption, which increased the adsorption capacities of TC on UPSM by two to three times. The adsorption mechanism was possibly determined by the molecular interaction including π–π forces, cation-π bonding, and hydrogen bonding. The simple surface modification was helpful in enhancing the removal of antibiotics from wastewater with similar structures.

scholarly journals Highly effective removal of antibiotics from aqueous solution by magnetic ZnFe2O4/activated carbon composite

2020 ◽  
Vol 82 (5) ◽  
pp. 877-886
Author(s):  
Yun-Xia Li ◽  
Lei Wang ◽  
Fang-Fang Chai ◽  
Hong-Fei Jing ◽  
Zhu-Qing Gao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Carbon Composite ◽  
Liquid System ◽  
Mechanism Analysis ◽  
Solution Ph ◽  
Adsorption Capacities ◽  
Effective Removal ◽  
Solid Liquid

Abstract Water pollution from antibiotics has attracted a lot of attention for its serious threat to human health. In this study, a magnetic adsorbent (zinc ferrite/activated carbon (ZnFe2O4/AC) was synthesized via microwave method to effectively remove gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). Based on the porosity of AC and the magnetism of ZnFe2O4, the resulting ZnFe2O4/AC has high adsorption capacities and can be easily separated from the solid–liquid system via a magnetic field. The largest adsorption capacities for GEM and MOX can reach up to 433.4 mg g−1 and 388.8 mg g−1, respectively, higher than those of reported adsorbents such as MIL-101 and MOF-808. Fastest adsorptions of GEM and MOX were found at 5 min, and solution pH and coexisting salts do not have a significant influence on the adsorption process. The adsorption mechanism analysis indicates that electrostatic interaction and H-bond interaction contribute to the effective adsorption.

scholarly journals Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak
Keyword(s):  
Freeze Drying ◽  
Jerusalem Artichoke ◽  
Polyphenolic Compounds ◽  
Raw Material ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Activity Inhibition ◽  
Health Promoting

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.

scholarly journals Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Thermal Insulation ◽  
Freeze Drying ◽  
Thermal Infrared ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
List Type ◽  
Drying Method ◽  
Cross Sectional ◽  
Compression Resistance

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

scholarly journals Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration

2020 ◽  
Vol 18 (1) ◽  
pp. 584-590 ◽  
Author(s):  
◽  
Dyah Hikmawati ◽  
Umi Kulsum ◽  
Djony Izak Rudyardjo ◽  
Retna Apsari ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Freeze Drying ◽  
Bone Growth ◽  
Viable Cell ◽  
Drying Method ◽  
Porous Composite ◽  
Viable Cells

AbstractThe synthesis of collagen–hydroxyapatite composites has been carried out, and the biocompatibility and osteoconductivity properties have been tested. This research was conducted to determine the ability of hydroxyapatite–collagen composites to support the bone growth through the graft surface. Hydroxyapatite used in this study was synthesized from coral with a purity of 96.6%, while collagen was extracted from the chicken claw. The process of forming a scaffold of collagen–hydroxyapatite composites was carried out using the freeze-drying method at −80°C for 4 h. The biocompatibility characteristics of the sample through the cytotoxicity tests showed that the percentage of viable cells in collagen–hydroxyapatite biocomposite was 108.2%, which is higher than the percentage of viable cells of hydroxyapatite or collagen material. When the viable cell is above 100%, collagen–hydroxyapatite composites have excellent osteoconductivity as a material for bone regeneration.

Construction of a CsPbBr3 modified porous g-C3N4 photocatalyst for effective reduction of CO2 and mechanism exploration

2021 ◽  
Author(s):  
Yunqi Wang ◽  
Zhixiang Liu ◽  
Xu Tang ◽  
Pengwei Huo ◽  
Zhi Zhu ◽  
...  
Keyword(s):  
High Temperature ◽  
Porous Structure ◽  
Freeze Drying ◽  
Drying Method ◽  
Full Spectrum ◽  
Effective Reduction ◽  
Reduction Of Co2 ◽  
High Temperature Calcination

A P-CN/CsPbBr3 photocatalyst with a lamellar porous structure was prepared by a high temperature calcination and freeze drying method, and it exhibited superior CO2 reduction performance under the conditions of full spectrum irradiation.

CdS and Cd carboxylate nanoclusters dispersed in polymer matrix produced by a freeze drying method

2013 ◽  
Vol 49 (11) ◽  
pp. 3530-3538 ◽  
Author(s):  
Chonggang Wu ◽  
Thomas J. Emge ◽  
Frederic Cosandey ◽  
Masanori Hara
Keyword(s):  
Polymer Matrix ◽  
Freeze Drying ◽  
Drying Method

Sequential Infrared Radiation and Freeze-Drying Method for Producing Crispy Strawberries

2008 ◽  
Vol 51 (1) ◽  
pp. 205-216 ◽  
Author(s):  
C. Shih ◽  
Z. Pan ◽  
T. McHugh ◽  
D. Wood ◽  
E. Hirschberg
Keyword(s):  
Infrared Radiation ◽  
Freeze Drying ◽  
Drying Method

Ruthenium Recovery from Acetic Acid Waste Solution by Using PEI-Coated Biomass-Chitosan Composite Fiber

2015 ◽  
Vol 1130 ◽  
pp. 577-580 ◽  
Author(s):  
Jeong Ae Kim ◽  
Myung Hee Song ◽  
Yeoung Sang Yun
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Freeze Drying ◽  
Ion Exchange Resin ◽  
Composite Fiber ◽  
Drying Methods ◽  
Drying Method ◽  
Waste Solution ◽  
Chitosan Composite ◽  
Acid Waste

Polyethylenimine (PEI)-coated biomass-chitosan composite fiber (PBCF) was fabricated to recover Ru from acetic acid waste solution. The present work aimed to understand the effects of molecular weight of chitosan and drying method on stability and sorption performance of the PBCF. For this, the PBCF was prepared by extruding the mixed solutions of chitosan and Corynebacteriumglutamicum to form the composite fibers which were modified with ionic polymer, PEI. The degree of swelling of PBCFs prepared by hot-air, natural, and freeze drying methods were 1.25, 1.34, and 1.07 %, respectively, indicating that the freeze-drying method was the best. Batch biosorption studies showed that the maximum Ru uptake could be achieved with PBCF prepared with medium molecular weight chitosan, and could reach 34.1 mg/g, which was 7.9 times higher than that of the commercial ion exchange resin, LEWATIT® MonoPlus M 500 (4.3 mg/g). Therefore, PBCF can be considered as an alternative sorbent to synthetic resin for recovery of Ru form industrial acetic acid waste solution.

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