Adsorption characteristics of chitooligosaccharides onto activated charcoal in aqueous solutions

To investigate the adsorption characteristics of chitooligosaccharides in solution onto activated charcoal,we studied the optimal adsorption conditions and the adsorption mechanisms of the chitooligosaccharides onto activated charcoal,which will greatly promote the application of activated charcoal in the chitooligosaccharides separation and purification.We studied the effects of particle size of activated charcoal,pH of solution,contact time,temperature,and initial concentration of chitooligosaccharides on the adsorption behavior in batch mode experiments.Activated charcoal in fine particle size showed a high uptake of chitooligosaccharides.Weak alkaline solution(pH 8–9)was the most favorable to the adsorption.The adsorption equilibrium after 60 min was established,which followed a pseudo-second-order kinetic model.The adsorption capacity(Q_(max))reached 0.195 g/g(chitooligosaccharides/activated charcoal)at 298 K.The adsorption was temperature-insensitive,and the adsorption isotherms could be best described by the Langmuir equation.Chitooligosaccharides adsorbed on activated charcoal could be desorbed in 50%ethanol solution in combination with an acidic condition(pH 2),reaching desorption efficiency of 96.0%.These findings are of great significance for the production and purification of amino oligosaccharides including chitooligosaccharides using activated charcoal.

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal composite

Composite materials have elicited much interest because of their superior performance in the removal of toxic and radioactive uranyl ions from aqueous solutions.With polyethyleneimine as a functional group,carboxylated chitosan as a matrix,and oxidizing activated carbon as a nanofiller,this study synthesized a novel environment-friendly polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal(PCO)biocomposite with a unique three-dimensional porous structure.PCO was synthesized through an easy chemical cross-linking method.Detailed characterization certified the formation of the unique three-dimensional porous structure.The obtained PCO was used to remove uranyl ions from an aqueous solution,demonstrating the maximum adsorption capacity of 450 mg·g^(−1).The adsorption capacity of PCO decreased by less than 7.51%after five adsorption-desorption cycles.PCO exhibited good adsorption selectivity(K_(d)=3.45×10^(4) mL·g^(−1))for uranyl ions.The adsorption mechanism of PCO was also discussed.The material showed good potential for application in the treatment of wastewater containing uranyl ions.

Effect of Porous Activated Charcoal Reinforcement on Mechanical and In-Vitro Biological Properties of Polyvinyl Alcohol Composite Scaffolds

The present work focused on developing an innovative composite material by reinforcing polymer matrix with highly porous activated charcoal. Polyvinyl alcohol-activated charcoal（PVA-AC） composite scaffolds were developed by varying the AC concentrations（0, 0.5, 1, 1.5, 2 and 2.5 wt%） in PVA matrix by freeze drying method. The developed scaffolds were characterized for their physicochemical, mechanical and in-vitro biological properties. In addition, the effect of AC on the attachment, proliferation and differentiation of osteoblast MG 63 cells was evaluated by scanning electron microscopy（SEM）, 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） assay, alkaline phosphatase（ALP） activity assay and alizarin red stain-based（ARS） assay. All the PVA-AC composite scaffolds exhibited good bioactivity, hemocompatibility and protein adsorption properties. The scaffolds with high AC concentration（2.5 wt%） showed controlled drug release kinetics that are suitable for long term healing. The mechanical properties of all the PVA-AC composite scaffolds were improved when compared to the pure PVA scaffold. The high porosity, swelling degree and hydrophilicity of PVA-AC composite scaffolds facilitated cell attachment and proliferation. This is due to porous AC present in the sample that supported the osteoblast differentiation and formed mineralized nodules without the addition of any extra agents. From the above studies, it can be concluded that PVA-AC composite scaffolds are promising biomaterials for bone tissue engineering applications.

Atrazine removal from water by activated charcoal cloths

Pollution control structures may be adapted to enhance the removal of nutrients and pesticides from water. Charcoal-like material is known to sorb organic compounds in solution, including atrazine, a herbicide used to control broadleaf weeds, which persists in soils and can migrate from soils to water bodies, ultimately affecting water quality. The primary goal of this study was to investigate if activated charcoal cloths (single-weave, SW;double-weave, DW;and knitted, KT) are more efficient to remove atrazine from aqueous solutions than a cloth without activated charcoal (control) currently used in pollution control structures. The approach consisted of sorption kinetics, flow-through, and desorption/degradation experiments using 50 and 1000μg L-1 atrazine solutions. Results showed that within 30 min of contact time, the control sorbed from 22.6 to 36.1% of atrazine in solution;whereas the activated charcoal cloths sorbed from 76 to 99% of atrazine in solution (SW > KT > DW). The flow-through ex-periments showed that the SW sorbed 88.2, 76.1, and 52.2%of atrazine at the contact time of 0.75, 5, and 10 min, respectively. After 28 days of incubation, previously sorbed atrazine on the SW cloth did not degrade and <2.0% was desorbed. The results showed that activated charcoal cloths are a practical alternative for improving atrazine removal in water in pollution control structures.

Management of acute carbamazepine poisoning:A narrative review

Standard management protocols are lacking and specific antidotes are unavailable for acute carbamazepine(CBZ)poisoning.The objective of this review is to provide currently available information on acute CBZ poisoning,including its management,by describing and summarizing various therapeutic methods for its treatment according to previously published studies.Several treatment methods for CBZ poisoning will be briefly introduced,their advantages and disadvantages will be analyzed and compared,and suggestions for the clinical treatment of CBZ poisoning will be provided.A literature search was performed in various English and Chinese databases.In addition,the reference lists of identified articles were screened for additional relevant studies,including non-indexed reports.Nonpeer-reviewed sources were also included.In the present review,154 articles met the inclusion criteria including case reports,case series,descriptive cohorts,pharmacokinetic studies,and in vitro studies.Data on 67 patients,including 4 fatalities,were reviewed.Based on the summary of cases reported in the included articles,the cure rate of CBZ poisoning after symptomatic treatment was 82%and the efficiency of hemoperfusion was 58.2%.Based on the literature review,CBZ is moderately dialyzable and the recommendation for CBZ poisoning is supportive management and gastric lavage.In severe cases,extracorporeal treatment is recommended,with hemodialysis as the first choice.

In vitro propagation of a medicinal plant: Tripterygium wilfordii Hook f.

In this study a reliable protocol was developed for the establishment of commercial in vitro cultures of Tripterygium wilfordii Hook f.. Juvenile shoots from one-year-old elite plants were used as the source of explants. New axillary shoots were obtained after 30 days of culture on a MS medium supplemented with BAP （2.0 mg.L^-1） and NAA （0.1 mg.L^-1）. The optimal multiplication medium was a modified MS medium supplemented with BAP （1.0 mg.L^-1） and NAA （0.1 mg.L^-1）. This yielded a multiplication rate of 2.4 for each subculture. Slightly more than 92% of shoots rooted when cultured on a modified MS medium containing IBA （0.2 mg.L^-1） and activated charcoal （0.5 mg.L^-1）. Activated charcoal promoted both a strong and a high rooting rate during the rooting phase. Plantlets were transferred to pots for a short acclimatization stage in a greenhouse where 95% of the plantlets survived. This highly reproducible procedure can be adopted for large-scale propagation of T. wilfordii.

Cryopreservation of Cyrtopodium hatschbachii Pabst (Orchidaceae) immature seeds by encapsulation-dehydration

The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds.Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique.Seeds of five immature pods,120 days after pollination,were encapsulated in 3%calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose(24 h),0.15 M sucrose(24 h),0.25 M sucrose(48 h),0.5 M sucrose(24 h)and 0.75 M sucrose(24 h)in shaker at 60 rpm.Alginate beads were dehydrated 5 h in silicagel and immersed in liquid nitrogen for 12 h.Cryopreserved beads were thawed at 30℃ for 1 min,rehydrated using the same liquid mediums[0.75 M sucrose(24 h),0.5 M sucrose(24 h),0.25 M sucrose(48 h)and 0.15 M sucrose(24 h)]and cultivated in half strength Murashige&Skoog medium(1962)with the addition of 2 g/L activated charcoal.Sixty four percent of seeds survived and developed into acclimatized plants after being cryopreserved.In this work,the encapsulation-dehydration technique was employed for first time in Cyrtopodium hatschbachii.

发光二极管用于活性炭负载光催化剂反应器中挥发性有机化合物的降解(英文)

The applicability of ultraviolet-light emitting diodes(LEDs)as a light source for photocatalysis using granular activated charcoal (GAC)impregnated with transition metal-enhanced photocatalysts for the control of volatile organic compounds(VOCs)was investigated. Two target compounds(toluene and methyl mercaptan)were selected to evaluate the removal activities of the TiO2/GAC composites.The photocatalysts were prepared by a sol-gel method.Methyl trimethoxy silane was added as a precursor sol solution to bind the photocatalyst with the GAC.Metal(Zn 2+ ,Fe 3+ ,Ag + ,and Cu 2+ )enhanced TiO2/GAC composites were prepared and tested for their photocatalytic activities under 400 nm LED irradiation.The specific surface area(SSA)and the surface chemical composition of the prepared composites were investigated.The SSAs of all the impregnated composites were similar to those of pure GAC.Both field emission-scanning electron microscopy and energy dispersive spectroscopic analysis confirmed that titanium and the impregnated metals were deposited on the surface of the adsorbent.The breakthrough time for GAC toward toluene or methyl mercaptan gas increased upon photocatalytic impregnation and LED illumination.Using different binders affected the breakthrough time of the TiO2/GAC composite and the addition of zinc oxide to TiO2 increased the VOC removal capacity of the GAC composite.