A series of MgO-based adsorbents were prepared through solution–combustion synthesis and ball-milling process.The prepared MgO-based powders were characterized using X-ray diffraction,scanning electron microscopy,N_2...A series of MgO-based adsorbents were prepared through solution–combustion synthesis and ball-milling process.The prepared MgO-based powders were characterized using X-ray diffraction,scanning electron microscopy,N_2 physisorption measurements,and employed as potential adsorbents for CO_2 adsorption.The influence of structural and textural properties of these adsorbents over the CO_2 adsorption behaviour was also investigated.The results showed that MgO-based products prepared by solution–combustion and ball-milling processes,were highly porous,fluffy,nanocrystalline structures in nature,which are unique physico-chemical properties that significantly contribute to enhance their CO_2 adsorption.It was found that the MgO synthesized by solution combustion process,using a molar ratio of urea to magnesium nitrate（2：1）,and treated by ball-milling during 2.5 hr（MgO-BM2.5h）,exhibited the maximum CO_2 adsorption capacity of 1.611 mmol/g at 25℃ and 1 atm,mainly via chemisorption.The CO_2 adsorption behaviour on the MgO-based adsorbents was correlated to their improved specific surface area,total pore volume,pore size distribution and crystallinity.The reusability of synthesized MgO-BM2.5h was confirmed by five consecutive CO_2adsorption–desorption times,without any significant loss of performance,that supports the potential of MgO-based adsorbent.The results confirmed that the special features of MgO prepared by solution–combustion and treated by ball-milling during 2.5 hr are favorable to be used as effective MgO-based adsorbent in post-combustion CO_2 capture technologies.展开更多
Currently,the solid adsorbents with porous structure have been widely applied in CO_(2)capture.However,the unmodified MgO-ZrO_(2)adsorbents appeared to be low adsorption capacity of CO_(2).The solid adsorbent material...Currently,the solid adsorbents with porous structure have been widely applied in CO_(2)capture.However,the unmodified MgO-ZrO_(2)adsorbents appeared to be low adsorption capacity of CO_(2).The solid adsorbent materials were successfully synthesized by loading TEPA onto the pore MgO/ZrO_(2)carriers in the paper.The pore structure and surface characteristic of the samples were analyzed by using XRD,BET,FT-IR and SEM.The adsorbent materials exhibited microcrystalline state,and the crystallinity of all samples gradually decreased as the increase of TEPA content.The pore structure analysis indicated that the modification of MgO-ZrO_(2)adsorbents with TEPA led to the decrease of the specific surface areas,but the narrow micro-mesopore size distributions ranging from 1.8-12 nm in the adsorbents still were maintained.FT-IR spectrum results further verified the successful loading of TEPA.The adsorption capacity of the adsorbents for CO_(2)were tested by using an adsorption apparatus equipped with gas chromatography.The results indicated that when the TEPA loading reached 50%,the sample exhibited the maximum adsorption value for CO_(2),reaching 4.07 mmol/g under the operation condition of 75℃and atmospheric pressure.This result could be assigned to not only the base active sites but also the coexistence of both micropore and mesopore in the adsorbent.After three cycles tests for CO_(2)capture,the adsorption value of the sample for CO_(2)can also reached 95%of its original adsorption capacity,which verified the excellent cyclic operation stability.展开更多
Pure magnesia filter and periclase-spinel filter were prepared using porous MgO powder and Al2O3 micro-powder as raw materials.The filtration efficiency and purification mechanism of the two sets of filters on molten ...Pure magnesia filter and periclase-spinel filter were prepared using porous MgO powder and Al2O3 micro-powder as raw materials.The filtration efficiency and purification mechanism of the two sets of filters on molten steel were investigated through steel casting tests.The results show that on the basis of surviving the thermal shock of molten steel,both filters can significantly reduce the number of non-metallic inclusions and total oxygen content of steel,thereby improving the cleanliness of the molten steel.After the thermal shock of molten steel,cracks were found in the microstructure of pure magnesia filter.Via the diffusion of non-metallic inclusions from steel into MgO grains of the filter to form solid solution,the inclusions were adsorbed to the internal and external surfaces of the pure magnesia filter.The number of inclusions was reduced by 62.5%,and the total oxygen content decreased from 0.892 to 0.265 wt.%after filtration,achieving a filtration efficiency of 70.3%.Compared with the pure magnesia filter,no cracks were found in the microstructure of the periclase-spinel filter.The mass transfer rate was accelerated due to the diffusion of inclusions from steel into MgO and MgAl2O4 grains of the filter,as well as the higher high-temperature liquid content and smaller pore structure of the filter.More non-metallic inclusions were able to enter the interior of the filter,which made the periclase-spinel filter more capable of adsorbing inclusions from steel and reducing total oxygen content.The periclase-spinel filter reduced the number of inclusions in steel by 84.4%and decreased the total oxygen content of the steel from 0.892 to 0.119 wt.%,with a filtration efficiency of 86.7%,demonstrating excellent comprehensive performance.展开更多
Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their pra...Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.展开更多
Hospital wastewater contains complex pollutants,including residual organic dyes and antibiotic-resistant pathogens,posing severe risks to ecosystems and human health.Conventional adsorbents,constrained by monopolar fu...Hospital wastewater contains complex pollutants,including residual organic dyes and antibiotic-resistant pathogens,posing severe risks to ecosystems and human health.Conventional adsorbents,constrained by monopolar functional groups and limited surface sites,fail to remove both pollutants simultaneously.Here,we report an intelligent responsive polyurethane microsphere adsorbent doped with diallyl dimethylammonium chloride modified carbon nanotubes,termed as PUCD microspheres.The PUCD integrates bipolar adsorption sites,tunable micrometer-scale pores,and a near-infrared(NIR)-triggered in situ capture mechanism within a single platform,which achieves up to 98.3%dye removal,maintains strong adsorption performance across a wide pH range and retains 83.3%efficiency for rhodamine B after five cycles.Notably,the PUCD employs a temperature-responsive phase transition:under NIR irradiation,the microspheres undergo shrinkage,reducing the pore size to generate a‘polymer trap',enabling in situ capture of bacteria with>99%efficiencies for both Staphylococcus aureus and Escherichia coli.By immobilizing live bacteria,the PUCD microspheres substantially reduces the risk of pathogen desorption and toxin release.This promising platform offers a safe,efficient,and single-stage strategy for hospital wastewater purification,enabling the simultaneous elimination of dyes and pathogenic bacteria.展开更多
A series of copper-based activated carbon (AC) adsorbents were prepared in order to investigate the effect of Zn, Ce addition on Cu-based AC adsorbent for phosphine (PH3) adsorption removal from yellow phosphorous tai...A series of copper-based activated carbon (AC) adsorbents were prepared in order to investigate the effect of Zn, Ce addition on Cu-based AC adsorbent for phosphine (PH3) adsorption removal from yellow phosphorous tail gas. N2 adsorption isotherm and X-ray diffrac-tion (XRD) results suggested that the addition of Zn could increase the adsorbent ultramicropores, decrease the adsorbent supermicropores and the adsorbent average pore diameter. Therefore it enhanced the PH3 adsorption capacity. Appropriate amoun...展开更多
The increase in energy demand caused by industrialization leads to abundant CO_2 emissions into atmosphere and induces abrupt rise in earth temperature. It is vital to acquire relatively simple and cost-effective tech...The increase in energy demand caused by industrialization leads to abundant CO_2 emissions into atmosphere and induces abrupt rise in earth temperature. It is vital to acquire relatively simple and cost-effective technologies to separate CO_2 from the flue gas and reduce its environmental impact. Solid adsorption is now considered an economic and least interfering way to capture CO_2, in that it can accomplish the goal of small energy penalty and few modifications to power plants. In this regard, we attempt to review the CO_2 adsorption performances of several types of solid adsorbents, including zeolites, clays, activated carbons, alkali metal oxides and carbonates, silica materials, metal–organic frameworks, covalent organic frameworks, and polymerized high internal phase emulsions. These solid adsorbents have been assessed in their CO_2 adsorption capacities along with other important parameters including adsorption kinetics, effect of water, recycling stability and regenerability. In particular,the superior properties of adsorbents enhanced by impregnating or grafting amine groups have been discussed for developing applicable candidates for industrial CO_2 capture.展开更多
Two organobentonites were synthesized by placing quaternary ammonium cationscetyltrimethylammonium bromide (CTMAB) and cetylpyridinium chloride (CPC) on bentonite bycation exchange. Their ability to adsorb phenol, ani...Two organobentonites were synthesized by placing quaternary ammonium cationscetyltrimethylammonium bromide (CTMAB) and cetylpyridinium chloride (CPC) on bentonite bycation exchange. Their ability to adsorb phenol, aniline. nitrobenzene and p-nitrophenol were examined.The optimal conditions for organobentonites to remove the organic pollutants from waterwere studied. The removal rates for organobentonites to treat the organic compounds in water werefound to be over 8 times for the original mineral (untreated bentonite).The removal rates of organic pollutants and COD of wastewater were further improved by organobentonites in the presence of aluminum sulfate. The structure of organobentonites and the mechanism for their adsorption were investigated by X-ray diffraction (XRD) analysis, infrared spectra and BET surface area.展开更多
Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous c...Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous chemical industry tail gas,the concentration of which is always more than 80 vol.%,and it can be the feed gas to produce various valuable products such as formate,oxalate,and methanol and so on.But,PH3 is one of the important barriers,which is harmful to the following chemical process.In order to make use of the tail gas,PH3 should be removed firstly,and CO should be covered in the whole purified procedure at the same time.In this work,the modified activated carbon(MAC) was used as the adsorbent to separate PH3 from the mixture tail gas.Series of MAC adsorbents were prepared for the adsorption of PH3,which loaded Cu-Fe and Ce(La),or separately.The PH3 adsorption capacities,chemical and physical properties of MAC were all investigated.The results showed that over 99% PH3 adsorption efficiency was achieved when used MAC adsorbents.The removal efficiency and PH3 adsorption capacity of the Cu-Fe-Ce/AC(20:1:0.4) were both much higher than those modified activated carbons.The maximum PH3 adsorption capacity was 71 mg of PH3/g of MAC on the Cu-Fe-Ce/AC,which were much higher than literature data using CuO only for adsorbing hydride gases.展开更多
In this study, we prepared and applied polymeric porous microsphere adsorbents with selectivity for Li^+ extraction from aqueous solution. We synthesized the adsorbents by suspension polymerization using methacryloyox...In this study, we prepared and applied polymeric porous microsphere adsorbents with selectivity for Li^+ extraction from aqueous solution. We synthesized the adsorbents by suspension polymerization using methacryloyoxyme-12-crown-4(M12C4) as a functional monomer, which had been synthesized from 2-hyroxymethyl-12-crown-4 and methacryloyl chloride. We verified the chemical composition by solid nuclear magnetic resonance(13C-NMR) spectroscopy and observed the porous structure by scanning electron microscopy(SEM). We conducted adsorption isothermal and kinetic tests to determine the adsorption properties. It was found that the adsorbents showed high adsorption efficiency and an adsorption equilibrium time of 200 min. In addition, since the crown ether used in this work could form a stable complex with Li^+, we observed good selectivity for Li^+ in the prepared solution compared with other ions such as Na^+, K^+, Mg^(2+), and Ca^(2+). We reused the adsorbents five times with no significant decrease in adsorptive capacity.展开更多
The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental r...The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.展开更多
Adsorption equilibrium isotherms of phenolic compounds, phenol, p cresol, p chlorophenol and p nitrophenol, from aqueous solutions by Amberlite XAD 4 polymeric adsorbent and its acetylized derivative M...Adsorption equilibrium isotherms of phenolic compounds, phenol, p cresol, p chlorophenol and p nitrophenol, from aqueous solutions by Amberlite XAD 4 polymeric adsorbent and its acetylized derivative MX 4 within temperature range of 283 323K were obtained and fitted to the Freundlich isotherms. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylized resin, which may be contributed to the specific surface area and the partial polarity on the network. Estimations of the isosteric enthalpy, free energy, and entropy for the adsorption process were reported.展开更多
This paper presents experimental observations on the adsorption of individual solutes by a simple thermodynamic framework, and the equilibrium adsorption of ethyl benzoate and diethyl phthalate on phenolic resin adsor...This paper presents experimental observations on the adsorption of individual solutes by a simple thermodynamic framework, and the equilibrium adsorption of ethyl benzoate and diethyl phthalate on phenolic resin adsorbent in hexane solutions within the temperature range of 293-313 K. The experimental results show that the Freundlich adsorption law is applicable to the adsorption of ethyl benzoate and diethyl phthalate on the adsorbent, since all the correlative factors R' are larger than 0.99. The negative values of all the isosteric adsorption enthalpies for ethyl benzoate and diethyl phthalate indicate that they undergo exothermic processes, while their magnitudes (19-28 kJ/mol) manifest a hydrogen bonding sorption process. Other thermodynamic properties: the free energy changes and the entropy change associated with the adsorption have been calculated from the Gibbs adsorption equation and the Gibbs-Helmholtz equation展开更多
Two hypercrosslinked polymeric adsorbents （ZH-01 and Amberlite XAD-4 resin） were employed to remove three kinds of phenolic compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The...Two hypercrosslinked polymeric adsorbents （ZH-01 and Amberlite XAD-4 resin） were employed to remove three kinds of phenolic compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The study was focused on the static equilibrium adsorption behavior, the column dynamic adsorption and desorption profiles. The Freundlich model gave a perfect fitting to the isotherm data. The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite XAD-4 within the temperature range 288-318 K, which was attributed to the large micropore area and 2-carboxybenzoyl functional groups on the network of ZH-01 resin. The adsorption for phenol and 4- nitrophenol on ZH-01 was a physical adsorption process, while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption＇s transitions. The column test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds. Being used as the desorption reagent, sodium hydroxide solution showed an excellent performance.展开更多
The adsorption behaviors of 1-naphthol, 1-naphthylamine and l-naphthol/l-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K...The adsorption behaviors of 1-naphthol, 1-naphthylamine and l-naphthol/l-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K respectively. All the adsorption isotherms in the studied systems can be adequately fitted by Langmuir model. In the case of aminated macroreticular adsorbent NDA103, 1-naphthol is adsorbed to a larger extent than 1-naphthylamine; while, the opposite trend is found for nonpolar macroreticular adsorbent NDA100. It is noteworthy that at higher temperature（303 K and 313 K）, the total uptake amounts of 1-naphthol and 1-naphthylamine in all binary-component systems are obvious larger than the pure uptake amounts in single-component systems, which is presumably due to the cooperative effect primarily arisen from the hydrogen-bonding interaction between the loaded 1-naphthol and 1-naphthylamine molecules. The simultaneous adsorption systems were confirmed to be helpful to the selective adsorption towards 1-naphthol according to the larger selective index.展开更多
The carbonaceous adsorbent was prepared from mixtures of dewatered sludge and sawdust with enhanced ZnCl2 chemical activation.Characteristics of the adsorbent were studied using scanning electron microscope(SEM) ,Four...The carbonaceous adsorbent was prepared from mixtures of dewatered sludge and sawdust with enhanced ZnCl2 chemical activation.Characteristics of the adsorbent were studied using scanning electron microscope(SEM) ,Fourier transform infrared spectroscopy(FT-IR) ,and adsorption of nitrogen.The surface analysis showed that the carbonaceous adsorbent had good specific surface and porosity(394 m 2 ·g-1of BET surface,0.12 and 0.10 ml·g-1of microporous and mesoporous volume,respectively) .The oxygen functional groups such as OH,C O and C O were found on the surface by FTIR and XPS(X-ray photoelectron spectroscopy) .The adsorption of elemental mercury(Hg0) on the carbonaceous adsorbent was studied in a fixed bed reactor.The dynamic adsorption capacity of carbonaceous adsorbent increased with influent mercury concentration,from 23.6μg·g-1at 12.58μg·m-3to 87.9μg·g-1at 72.50μg·m-3,and decreased as the adsorption temperature increased,from 246 μg·g-1 at 25°C to 61.3μg·g-1 at 140°C,when dry nitrogen was used as the carrier gas.The carbonaceous adsorbent presented higher dynamic adsorption capacity than activated carbon,which was 81.2μg·g-1and 53.8μg·g-1respectively.The adsorption data were fitted to the Langmuir adsorption model.The physical and chemical adsorption were identified on the adsorbent.展开更多
In this article, in vitro adsorption of aflatoxin B1 （AFB1） onto different adsorbents was characterized and the result was verified by comparing the growth performance and serum protein levels of broilers exposed to...In this article, in vitro adsorption of aflatoxin B1 （AFB1） onto different adsorbents was characterized and the result was verified by comparing the growth performance and serum protein levels of broilers exposed to aflatoxin-contamination feed. Main components of adsorbents selected were yeast cell extracts （Product A）, HSCAS （Product B）, and a mixture of yeast product and HSCAS （Product C）, respectively. A total of 240 broilers were assigned to eight treatments, and the effects of three types of adsorbents on growth performance and serum protein levels were evaluated. Results indicated that Product B had the highest in vitro affinity for AFB1, followed by Product C and Product A. Product B bound 97.69% of the AFB1 in solution in 10 min, and it remained over 96.03% in 60 min at pH 8.0. The B-AFB1 complex was much stronger than the other two complexes in vitro condition （P 〈 0.05）. Feed intake （FI） and average daily gain （ADG） decreased （P 〈 0.05） and feed gain ratio increased （P 〈0.05） in the treatment fed aflatoxin-contaminated feed versus treatment on the basal feed. Serum total protein （TP）, albumin （ALB）, and globulin （GLOB） levels were significantly decreased （P〈0.05）. Product B （0.15%） increased growth performance and improved serum protein levels, Product A and Product C were not as effective as Product B. Three adsorbents tested here had sufficient potential to AFBt in some extents and Product B could bind AFB1 more effectively than Product A and Product C. These results indicated that Product B could alleviate some of the AFBt toxic effect in broilers.展开更多
Plasma electrolytic oxidation(PEO)has held great potential for the advancement of biodegradable implants,as it helps in developing porous bioceramic coatings on the surface of magnesium alloys.In this research work,Mg...Plasma electrolytic oxidation(PEO)has held great potential for the advancement of biodegradable implants,as it helps in developing porous bioceramic coatings on the surface of magnesium alloys.In this research work,MgO-based bioceramic coatings containing the Si,P,Ca,Na,and F elements have been successfully fabricated on an AZ31 magnesium alloy plate utilizing the PEO method.The characteristic current-voltage behavior of the samples during the process was surveyed in an electrolyte containing Ca(H_(2)PO_(4))_(2),Na_(2)SiO_(3)·9H_(2)O,Na_(3)PO_(4)·12H_(2)O,NaF,and KOH with a pH of 12.5 and electrical conductivity of 20 mS/cm^(-1).The results revealed that applying a voltage of 350-400 V(that is 50-100 V higher than the breakdown limit)could greatly facilitate the synthesis of a PEO ceramic coating with fewer defects and more uniform morphology.The resulting coating was a compositionally graded bioceramic layer with a thickness in the range of 3.5±0.4 to 6.0±0.7µm,comprising the above-mentioned elements as promising bioactive agents.The synthesized ceramic features were investigated in terms of the elemental distribution of components through the thickness,which indicated a gradual rise in the Si and P contents and,conversely,a decline in the F content towards the outer surface.The growth mechanism of the PEO coating has been discussed accordingly.展开更多
Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized a...Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized adsorbents is regard as a direct and effective way to reducing CO_(2)emissions due to their large CO_(2)adsorption amount,excellent CO_(2)adsorption selectivity and lower energy requirements for adsorbent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO_(2)capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.展开更多
基金the National Institute of Nuclear Research(ININ),México,for financial support through project CB-406 stagesⅠ-Ⅲ
文摘A series of MgO-based adsorbents were prepared through solution–combustion synthesis and ball-milling process.The prepared MgO-based powders were characterized using X-ray diffraction,scanning electron microscopy,N_2 physisorption measurements,and employed as potential adsorbents for CO_2 adsorption.The influence of structural and textural properties of these adsorbents over the CO_2 adsorption behaviour was also investigated.The results showed that MgO-based products prepared by solution–combustion and ball-milling processes,were highly porous,fluffy,nanocrystalline structures in nature,which are unique physico-chemical properties that significantly contribute to enhance their CO_2 adsorption.It was found that the MgO synthesized by solution combustion process,using a molar ratio of urea to magnesium nitrate（2：1）,and treated by ball-milling during 2.5 hr（MgO-BM2.5h）,exhibited the maximum CO_2 adsorption capacity of 1.611 mmol/g at 25℃ and 1 atm,mainly via chemisorption.The CO_2 adsorption behaviour on the MgO-based adsorbents was correlated to their improved specific surface area,total pore volume,pore size distribution and crystallinity.The reusability of synthesized MgO-BM2.5h was confirmed by five consecutive CO_2adsorption–desorption times,without any significant loss of performance,that supports the potential of MgO-based adsorbent.The results confirmed that the special features of MgO prepared by solution–combustion and treated by ball-milling during 2.5 hr are favorable to be used as effective MgO-based adsorbent in post-combustion CO_2 capture technologies.
基金supported by Shanxi Provincial Key Research and Development Project(202102090301026)Graduate Education Innovation Project of Taiyuan University of Science and Technology(SY2023024)。
文摘Currently,the solid adsorbents with porous structure have been widely applied in CO_(2)capture.However,the unmodified MgO-ZrO_(2)adsorbents appeared to be low adsorption capacity of CO_(2).The solid adsorbent materials were successfully synthesized by loading TEPA onto the pore MgO/ZrO_(2)carriers in the paper.The pore structure and surface characteristic of the samples were analyzed by using XRD,BET,FT-IR and SEM.The adsorbent materials exhibited microcrystalline state,and the crystallinity of all samples gradually decreased as the increase of TEPA content.The pore structure analysis indicated that the modification of MgO-ZrO_(2)adsorbents with TEPA led to the decrease of the specific surface areas,but the narrow micro-mesopore size distributions ranging from 1.8-12 nm in the adsorbents still were maintained.FT-IR spectrum results further verified the successful loading of TEPA.The adsorption capacity of the adsorbents for CO_(2)were tested by using an adsorption apparatus equipped with gas chromatography.The results indicated that when the TEPA loading reached 50%,the sample exhibited the maximum adsorption value for CO_(2),reaching 4.07 mmol/g under the operation condition of 75℃and atmospheric pressure.This result could be assigned to not only the base active sites but also the coexistence of both micropore and mesopore in the adsorbent.After three cycles tests for CO_(2)capture,the adsorption value of the sample for CO_(2)can also reached 95%of its original adsorption capacity,which verified the excellent cyclic operation stability.
基金supported by the Key Project of the National Natural Science Foundation of China(Grant No.U21A2058 and U1860205)the Natural Science Funds of Hubei Province for Distinguished Young Scholars(Grant No.2020CFA088).
文摘Pure magnesia filter and periclase-spinel filter were prepared using porous MgO powder and Al2O3 micro-powder as raw materials.The filtration efficiency and purification mechanism of the two sets of filters on molten steel were investigated through steel casting tests.The results show that on the basis of surviving the thermal shock of molten steel,both filters can significantly reduce the number of non-metallic inclusions and total oxygen content of steel,thereby improving the cleanliness of the molten steel.After the thermal shock of molten steel,cracks were found in the microstructure of pure magnesia filter.Via the diffusion of non-metallic inclusions from steel into MgO grains of the filter to form solid solution,the inclusions were adsorbed to the internal and external surfaces of the pure magnesia filter.The number of inclusions was reduced by 62.5%,and the total oxygen content decreased from 0.892 to 0.265 wt.%after filtration,achieving a filtration efficiency of 70.3%.Compared with the pure magnesia filter,no cracks were found in the microstructure of the periclase-spinel filter.The mass transfer rate was accelerated due to the diffusion of inclusions from steel into MgO and MgAl2O4 grains of the filter,as well as the higher high-temperature liquid content and smaller pore structure of the filter.More non-metallic inclusions were able to enter the interior of the filter,which made the periclase-spinel filter more capable of adsorbing inclusions from steel and reducing total oxygen content.The periclase-spinel filter reduced the number of inclusions in steel by 84.4%and decreased the total oxygen content of the steel from 0.892 to 0.119 wt.%,with a filtration efficiency of 86.7%,demonstrating excellent comprehensive performance.
基金supported by the Fundamental Research Funds for the National Natural Science Foundation of China 52225003,22208021,22109004the National Key R&D Program of China 2022YFB4101702.
文摘Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.
基金financially supported by the National Natural Science Foundation of China(Nos.52473139 and U21A2098)。
文摘Hospital wastewater contains complex pollutants,including residual organic dyes and antibiotic-resistant pathogens,posing severe risks to ecosystems and human health.Conventional adsorbents,constrained by monopolar functional groups and limited surface sites,fail to remove both pollutants simultaneously.Here,we report an intelligent responsive polyurethane microsphere adsorbent doped with diallyl dimethylammonium chloride modified carbon nanotubes,termed as PUCD microspheres.The PUCD integrates bipolar adsorption sites,tunable micrometer-scale pores,and a near-infrared(NIR)-triggered in situ capture mechanism within a single platform,which achieves up to 98.3%dye removal,maintains strong adsorption performance across a wide pH range and retains 83.3%efficiency for rhodamine B after five cycles.Notably,the PUCD employs a temperature-responsive phase transition:under NIR irradiation,the microspheres undergo shrinkage,reducing the pore size to generate a‘polymer trap',enabling in situ capture of bacteria with>99%efficiencies for both Staphylococcus aureus and Escherichia coli.By immobilizing live bacteria,the PUCD microspheres substantially reduces the risk of pathogen desorption and toxin release.This promising platform offers a safe,efficient,and single-stage strategy for hospital wastewater purification,enabling the simultaneous elimination of dyes and pathogenic bacteria.
基金Project supported by the Key Program of National High Technology Research and Development Program of China (863 Program) (2008AA062602)the Young and Middle-aged Academic and Technical Back-up Personnel Program of Yunnan Province (2007PY01-10)the Analysis and Measurement Foundation of Kunming University of Science & Technology
文摘A series of copper-based activated carbon (AC) adsorbents were prepared in order to investigate the effect of Zn, Ce addition on Cu-based AC adsorbent for phosphine (PH3) adsorption removal from yellow phosphorous tail gas. N2 adsorption isotherm and X-ray diffrac-tion (XRD) results suggested that the addition of Zn could increase the adsorbent ultramicropores, decrease the adsorbent supermicropores and the adsorbent average pore diameter. Therefore it enhanced the PH3 adsorption capacity. Appropriate amoun...
基金Supported by the National Key Research & Development Program of China(2017YFB0603302)
文摘The increase in energy demand caused by industrialization leads to abundant CO_2 emissions into atmosphere and induces abrupt rise in earth temperature. It is vital to acquire relatively simple and cost-effective technologies to separate CO_2 from the flue gas and reduce its environmental impact. Solid adsorption is now considered an economic and least interfering way to capture CO_2, in that it can accomplish the goal of small energy penalty and few modifications to power plants. In this regard, we attempt to review the CO_2 adsorption performances of several types of solid adsorbents, including zeolites, clays, activated carbons, alkali metal oxides and carbonates, silica materials, metal–organic frameworks, covalent organic frameworks, and polymerized high internal phase emulsions. These solid adsorbents have been assessed in their CO_2 adsorption capacities along with other important parameters including adsorption kinetics, effect of water, recycling stability and regenerability. In particular,the superior properties of adsorbents enhanced by impregnating or grafting amine groups have been discussed for developing applicable candidates for industrial CO_2 capture.
文摘Two organobentonites were synthesized by placing quaternary ammonium cationscetyltrimethylammonium bromide (CTMAB) and cetylpyridinium chloride (CPC) on bentonite bycation exchange. Their ability to adsorb phenol, aniline. nitrobenzene and p-nitrophenol were examined.The optimal conditions for organobentonites to remove the organic pollutants from waterwere studied. The removal rates for organobentonites to treat the organic compounds in water werefound to be over 8 times for the original mineral (untreated bentonite).The removal rates of organic pollutants and COD of wastewater were further improved by organobentonites in the presence of aluminum sulfate. The structure of organobentonites and the mechanism for their adsorption were investigated by X-ray diffraction (XRD) analysis, infrared spectra and BET surface area.
基金Project supported by the Key Program of National High Technology Research and Development Program of China (863 Program) (2008AA062602)the Young and Middle-aged Academic and Technical Back-up Personnel Program of Yunnan Province (2007PY01-10)
文摘Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous chemical industry tail gas,the concentration of which is always more than 80 vol.%,and it can be the feed gas to produce various valuable products such as formate,oxalate,and methanol and so on.But,PH3 is one of the important barriers,which is harmful to the following chemical process.In order to make use of the tail gas,PH3 should be removed firstly,and CO should be covered in the whole purified procedure at the same time.In this work,the modified activated carbon(MAC) was used as the adsorbent to separate PH3 from the mixture tail gas.Series of MAC adsorbents were prepared for the adsorption of PH3,which loaded Cu-Fe and Ce(La),or separately.The PH3 adsorption capacities,chemical and physical properties of MAC were all investigated.The results showed that over 99% PH3 adsorption efficiency was achieved when used MAC adsorbents.The removal efficiency and PH3 adsorption capacity of the Cu-Fe-Ce/AC(20:1:0.4) were both much higher than those modified activated carbons.The maximum PH3 adsorption capacity was 71 mg of PH3/g of MAC on the Cu-Fe-Ce/AC,which were much higher than literature data using CuO only for adsorbing hydride gases.
基金supported by Tianjin University-Qinghai Nationalities University Joint Innovation Fund(no.2016XZC-0034)
文摘In this study, we prepared and applied polymeric porous microsphere adsorbents with selectivity for Li^+ extraction from aqueous solution. We synthesized the adsorbents by suspension polymerization using methacryloyoxyme-12-crown-4(M12C4) as a functional monomer, which had been synthesized from 2-hyroxymethyl-12-crown-4 and methacryloyl chloride. We verified the chemical composition by solid nuclear magnetic resonance(13C-NMR) spectroscopy and observed the porous structure by scanning electron microscopy(SEM). We conducted adsorption isothermal and kinetic tests to determine the adsorption properties. It was found that the adsorbents showed high adsorption efficiency and an adsorption equilibrium time of 200 min. In addition, since the crown ether used in this work could form a stable complex with Li^+, we observed good selectivity for Li^+ in the prepared solution compared with other ions such as Na^+, K^+, Mg^(2+), and Ca^(2+). We reused the adsorbents five times with no significant decrease in adsorptive capacity.
基金Project supported by the National Key Technology Research and Development Program of China(No.2006BAC02A15)Opening Foundation of Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection of China(No.JLCBE05006)the Qinglan Project of Jiangsu Province
文摘The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.
文摘Adsorption equilibrium isotherms of phenolic compounds, phenol, p cresol, p chlorophenol and p nitrophenol, from aqueous solutions by Amberlite XAD 4 polymeric adsorbent and its acetylized derivative MX 4 within temperature range of 283 323K were obtained and fitted to the Freundlich isotherms. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylized resin, which may be contributed to the specific surface area and the partial polarity on the network. Estimations of the isosteric enthalpy, free energy, and entropy for the adsorption process were reported.
基金This project was supported by the National Natural Science Foundation of China (No. 29974015).
文摘This paper presents experimental observations on the adsorption of individual solutes by a simple thermodynamic framework, and the equilibrium adsorption of ethyl benzoate and diethyl phthalate on phenolic resin adsorbent in hexane solutions within the temperature range of 293-313 K. The experimental results show that the Freundlich adsorption law is applicable to the adsorption of ethyl benzoate and diethyl phthalate on the adsorbent, since all the correlative factors R' are larger than 0.99. The negative values of all the isosteric adsorption enthalpies for ethyl benzoate and diethyl phthalate indicate that they undergo exothermic processes, while their magnitudes (19-28 kJ/mol) manifest a hydrogen bonding sorption process. Other thermodynamic properties: the free energy changes and the entropy change associated with the adsorption have been calculated from the Gibbs adsorption equation and the Gibbs-Helmholtz equation
基金supported by the Educational Bureau of Jiangsu Province,China(No.08KJD150020)Jiangsu Provincial Key Laboratory of Coastal Wetland Bio-resources and Environmental Protection(No.JLCBE09011)the Professorial and Doctor Funds of Yancheng Teachers College(No.09YSYJB0202)
文摘Two hypercrosslinked polymeric adsorbents （ZH-01 and Amberlite XAD-4 resin） were employed to remove three kinds of phenolic compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The study was focused on the static equilibrium adsorption behavior, the column dynamic adsorption and desorption profiles. The Freundlich model gave a perfect fitting to the isotherm data. The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite XAD-4 within the temperature range 288-318 K, which was attributed to the large micropore area and 2-carboxybenzoyl functional groups on the network of ZH-01 resin. The adsorption for phenol and 4- nitrophenol on ZH-01 was a physical adsorption process, while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption＇s transitions. The column test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds. Being used as the desorption reagent, sodium hydroxide solution showed an excellent performance.
基金The National Natural Science Foundation of China( No. 20274017) and the Nature Science Foundation of Jiangsu Province( No. BK2004415)
文摘The adsorption behaviors of 1-naphthol, 1-naphthylamine and l-naphthol/l-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K respectively. All the adsorption isotherms in the studied systems can be adequately fitted by Langmuir model. In the case of aminated macroreticular adsorbent NDA103, 1-naphthol is adsorbed to a larger extent than 1-naphthylamine; while, the opposite trend is found for nonpolar macroreticular adsorbent NDA100. It is noteworthy that at higher temperature（303 K and 313 K）, the total uptake amounts of 1-naphthol and 1-naphthylamine in all binary-component systems are obvious larger than the pure uptake amounts in single-component systems, which is presumably due to the cooperative effect primarily arisen from the hydrogen-bonding interaction between the loaded 1-naphthol and 1-naphthylamine molecules. The simultaneous adsorption systems were confirmed to be helpful to the selective adsorption towards 1-naphthol according to the larger selective index.
基金Supported by the Science and Technology Planning Project of Guangdong(2006A36701004)the Basic Research Program of the Ministry of Environmental Protection(zx_200910_02)
文摘The carbonaceous adsorbent was prepared from mixtures of dewatered sludge and sawdust with enhanced ZnCl2 chemical activation.Characteristics of the adsorbent were studied using scanning electron microscope(SEM) ,Fourier transform infrared spectroscopy(FT-IR) ,and adsorption of nitrogen.The surface analysis showed that the carbonaceous adsorbent had good specific surface and porosity(394 m 2 ·g-1of BET surface,0.12 and 0.10 ml·g-1of microporous and mesoporous volume,respectively) .The oxygen functional groups such as OH,C O and C O were found on the surface by FTIR and XPS(X-ray photoelectron spectroscopy) .The adsorption of elemental mercury(Hg0) on the carbonaceous adsorbent was studied in a fixed bed reactor.The dynamic adsorption capacity of carbonaceous adsorbent increased with influent mercury concentration,from 23.6μg·g-1at 12.58μg·m-3to 87.9μg·g-1at 72.50μg·m-3,and decreased as the adsorption temperature increased,from 246 μg·g-1 at 25°C to 61.3μg·g-1 at 140°C,when dry nitrogen was used as the carrier gas.The carbonaceous adsorbent presented higher dynamic adsorption capacity than activated carbon,which was 81.2μg·g-1and 53.8μg·g-1respectively.The adsorption data were fitted to the Langmuir adsorption model.The physical and chemical adsorption were identified on the adsorbent.
基金financial support from the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD12B03)
文摘In this article, in vitro adsorption of aflatoxin B1 （AFB1） onto different adsorbents was characterized and the result was verified by comparing the growth performance and serum protein levels of broilers exposed to aflatoxin-contamination feed. Main components of adsorbents selected were yeast cell extracts （Product A）, HSCAS （Product B）, and a mixture of yeast product and HSCAS （Product C）, respectively. A total of 240 broilers were assigned to eight treatments, and the effects of three types of adsorbents on growth performance and serum protein levels were evaluated. Results indicated that Product B had the highest in vitro affinity for AFB1, followed by Product C and Product A. Product B bound 97.69% of the AFB1 in solution in 10 min, and it remained over 96.03% in 60 min at pH 8.0. The B-AFB1 complex was much stronger than the other two complexes in vitro condition （P 〈 0.05）. Feed intake （FI） and average daily gain （ADG） decreased （P 〈 0.05） and feed gain ratio increased （P 〈0.05） in the treatment fed aflatoxin-contaminated feed versus treatment on the basal feed. Serum total protein （TP）, albumin （ALB）, and globulin （GLOB） levels were significantly decreased （P〈0.05）. Product B （0.15%） increased growth performance and improved serum protein levels, Product A and Product C were not as effective as Product B. Three adsorbents tested here had sufficient potential to AFBt in some extents and Product B could bind AFB1 more effectively than Product A and Product C. These results indicated that Product B could alleviate some of the AFBt toxic effect in broilers.
文摘Plasma electrolytic oxidation(PEO)has held great potential for the advancement of biodegradable implants,as it helps in developing porous bioceramic coatings on the surface of magnesium alloys.In this research work,MgO-based bioceramic coatings containing the Si,P,Ca,Na,and F elements have been successfully fabricated on an AZ31 magnesium alloy plate utilizing the PEO method.The characteristic current-voltage behavior of the samples during the process was surveyed in an electrolyte containing Ca(H_(2)PO_(4))_(2),Na_(2)SiO_(3)·9H_(2)O,Na_(3)PO_(4)·12H_(2)O,NaF,and KOH with a pH of 12.5 and electrical conductivity of 20 mS/cm^(-1).The results revealed that applying a voltage of 350-400 V(that is 50-100 V higher than the breakdown limit)could greatly facilitate the synthesis of a PEO ceramic coating with fewer defects and more uniform morphology.The resulting coating was a compositionally graded bioceramic layer with a thickness in the range of 3.5±0.4 to 6.0±0.7µm,comprising the above-mentioned elements as promising bioactive agents.The synthesized ceramic features were investigated in terms of the elemental distribution of components through the thickness,which indicated a gradual rise in the Si and P contents and,conversely,a decline in the F content towards the outer surface.The growth mechanism of the PEO coating has been discussed accordingly.
基金Supported by Research Foundation of Overseas Chinese Affairs Office,the State Council,P.R.China,and FujianProvincial Science and Technology Creation Foundation for Young Researchers(No.2 0 0 1J0 2 3)
文摘Sieve effect, complexation, ionic exchange, electrostatic interaction, hydrogen bonding, hydrophobic interaction, and molecular recognition based on molecular imprinting are comprehensively discussed.
基金supported by the National Natural Science Foundation of China(21878200 and 21676174)International S&T Cooperation Program of Shanxi province(201703D421038)+1 种基金Shanxi Scholarship Council of China(2017-036)Joint Fund of Shanxi Provincial Coal Seam Gas(2015012019)。
文摘Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized adsorbents is regard as a direct and effective way to reducing CO_(2)emissions due to their large CO_(2)adsorption amount,excellent CO_(2)adsorption selectivity and lower energy requirements for adsorbent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO_(2)capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.
