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
Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,...Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,amidoximebased radiation grafted adsorbents have been identified as effective for iron removal.In this study,an amidoximefunctionalized,radiation-grafted adsorbent synthesized from polypropylene waste(PPw-g-AO-10)was employed to remove iron from leached geological samples.The adsorption process was systematically optimized by investigating the effects of pH,contact time,adsorbent dosage,and initial ferric ion concentration.Under optimal conditions-pH1.4,a contact time of 90 min,and an initial ferric ion concentration of 4500 mg/L-the adsorbent exhibited a maximum iron adsorption capacity of 269.02 mg/g.After optimizing the critical adsorption parameters,the adsorbent was applied to the leached geological samples,achieving a 91%removal of the iron content.The adsorbent was regenerated through two consecutive cycles using 0.2 N HNO_(3),achieving a regeneration efficiency of 65%.These findings confirm the efficacy of the synthesized PPw-g-AO-10 as a cost-effective and eco-friendly adsorbent for successfully removing iron from leached geological matrices while maintaining a reasonable degree of reusability.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
Desulfurization technology is rather difficult and urgently needed for carbon dioxide(CO_(2))utilization in industry.A new Cu(I)-based adsorbent was synthesized and examined for the capacity of removing carbonyl sulfi...Desulfurization technology is rather difficult and urgently needed for carbon dioxide(CO_(2))utilization in industry.A new Cu(I)-based adsorbent was synthesized and examined for the capacity of removing carbonyl sulfide(COS)from a CO_(2)stream in an effort to solve the competitive adsorption between CO_(2)and COS and to seek opportunity to advance adsorption capacity.A wide range of character-ization techniques were used to investigate the physicochemical properties of the synthesized Cu(I)adsorbent featuringπ-complexation and their correlations with the adsorption performance.Meanwhile,the first principal calculation software CP2K was used to develop an understanding of the adsorption mechanism,which can offer useful guidance for the adsorbent regeneration.The synthesized Cu(I)adsorbent,prepared by using copper citrate and citric acid on the ZSM-5(SiO_(2)/Al_(2)O_(3)=25)carrier,outperformed other adsorbents with varying formulations and carriers in adsorption capacities.Through optimization of the preparation and adsorption conditions for various adsorbents,the breakthrough adsorption capacity(Qb)for COS was further enhanced from 2.19 mg/g to 15.36 mg/g.The formed stableπ-complex bonds between COS and Cu(I),as confirmed by density func-tional theory calculations,were verified by the significant improvement in the adsorption capacity after regeneration at 600°C.The above advantages render the novel synthesized Cu(I)adsorbent a promising candidate featuring cost-effectiveness,high efficacy and good regenerability for desulfurization from a CO_(2)stream.展开更多
This study introduced a microwave-assisted pyrolysis method for the rapid and efficientpreparation of boron-doped porous biochar. The resulting biochar exhibited a large specificsurface area (933.39 m^(2)/g), a rich p...This study introduced a microwave-assisted pyrolysis method for the rapid and efficientpreparation of boron-doped porous biochar. The resulting biochar exhibited a large specificsurface area (933.39 m^(2)/g), a rich porous structure (1.044 cm3/g), and abundant active sites.Consequently, the prepared boron-doped porous biochar exhibited higher efficiency in adsorbingtetracycline with a maximum adsorption capacity of 413.223 mg/g, which significantlyexceeded that of unmodified biochar andmost commercial and reported adsorbents.The correlation analysis between the adsorption capacity and adsorbent characteristics revealedthat the formation of the –BCO_(2) group enhanced π–π electron donor–acceptor interactionsbetween boron-doped porous biochar and tetracycline. This mechanism mainlycontributed to the enhanced adsorption of tetracycline by boron-doped porous biochar. Additionally,the as-prepared boron-doped porous biochar exhibited broad applications in removingantibiotics (tetracycline), phenolics (bisphenol A), and dyes (methylene blue andrhodamine B). Moreover, the boron-doped porous biochar exhibited satisfactory stability,and its adsorption capacity can be nearly completely regenerated through simple heat treatment.This study provides new insights into the effectiveness of boron-doped carbonaceousmaterials in removing antibiotic contaminants.展开更多
Sodium-based adsorbents(Na_(2)CO_(3)/γ-Al_(2)O_(3))exhibit significant potential for commercial utilization in CO_(2)capture.Nevertheless,the requirement for high desorption temperatures poses challenges in terms of ...Sodium-based adsorbents(Na_(2)CO_(3)/γ-Al_(2)O_(3))exhibit significant potential for commercial utilization in CO_(2)capture.Nevertheless,the requirement for high desorption temperatures poses challenges in terms of the high-quality heat needed for desorption.This study integrated ZrO_(2)doping into a sodium-based adsorbent to enhance its CO_(2)capture performance and lower its desorption temperature.The research investigated the CO_(2)adsorption capacity,reaction rate,and desorption characteristics of the ZrO_(2)-doped Na_(2)CO_(3)/γ-Al_(2)O_(3)adsorbents in detail.Additionally,the catalytic mechanism of ZrO_(2)was elucidated through Density Functional Theory calculations.The results showed that ZrO_(2)doping increased the adsorption rate and capacity of the adsorbent and reduced the desorption energy consumption.Desorption reaction activation energy reduced to 44.8 kJ/mol.The adsorbent doped with 3wt.%ZrO_(2)demonstrated the highest adsorption capacity and rate under optimal conditions,with a reaction temperature of 45℃,an adsorption capacity of 1.66 mmol/g,and a carbon conversion rate of 80.2%.ZrO_(2)acted as a catalyst,enhancing CO_(2)and H_(2)O adsorption,and facilitated CO_(2)desorption in the sodium-based adsorbent by forming[ZrO(OH)]^(+)and OH^(−)through H_(2)O adsorption activation.The lower energy barrier(0.17 eV)for the dissociative adsorption pathway of H_(2)O molecules on the ZrO_(2)surface further supported the role of ZrO_(2)in enhancing the overall adsorption performance of the adsorbent in the carbon capture process.Ultimately,the ZrO_(2)-doped Na_(2)CO_(3)/γ-Al_(2)O_(3)adsorbent was identified as having low desorption energy consumption,high adsorption capacity,and rate,offering potential cost reductions in CO_(2)capture and representing a promising adsorbent for this application.展开更多
With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environmen...With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.展开更多
A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demo...A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.展开更多
The goal of this work is,first of all,to construct a mathematical model of the mass transfer process in porous adsorption layers,taking into account the fact that in most cases the adsorption process is carried out in...The goal of this work is,first of all,to construct a mathematical model of the mass transfer process in porous adsorption layers,taking into account the fact that in most cases the adsorption process is carried out in nonstationary technological modes,which requires a clear description of its various stages.The scientific contribution of the novel model is based on a probability approach allowing for deriving a differential equation that takes into account the diffusion migration of adsorbed particles.Solving this equation allows us to calculate the reduced degree of the adsorption surface coverage along the flow and,thereby,calculate the efficiency of the mass transfer process.The model also makes it possible to determine the slip coefficient,the internal diffusion coefficient and the degree of filling of the internal surface of the pores of the adsorbent layer,which corresponds to the completion of the initial stage of adsorption and the transition of the process to a stable mode.In this case,the problem is to calculate a non-isothermal turbulent boundary layer when flowing around the surface of an adsorbent.Next,the problem of identifying the main control parameters of the model has been solved.Based on such analysis and experimental studies to assess the influence of process control parameters,the patterns of adsorption purification and solution separation have been established and the design of a highly efficient adsorption apparatus with a fixed layer of porous adsorbent have been developed.展开更多
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.
文摘Geological samples often contain significant amounts of iron,which,although not typically the target element,can substantially interfere with the analysis of other elements of interest.To mitigate these interferences,amidoximebased radiation grafted adsorbents have been identified as effective for iron removal.In this study,an amidoximefunctionalized,radiation-grafted adsorbent synthesized from polypropylene waste(PPw-g-AO-10)was employed to remove iron from leached geological samples.The adsorption process was systematically optimized by investigating the effects of pH,contact time,adsorbent dosage,and initial ferric ion concentration.Under optimal conditions-pH1.4,a contact time of 90 min,and an initial ferric ion concentration of 4500 mg/L-the adsorbent exhibited a maximum iron adsorption capacity of 269.02 mg/g.After optimizing the critical adsorption parameters,the adsorbent was applied to the leached geological samples,achieving a 91%removal of the iron content.The adsorbent was regenerated through two consecutive cycles using 0.2 N HNO_(3),achieving a regeneration efficiency of 65%.These findings confirm the efficacy of the synthesized PPw-g-AO-10 as a cost-effective and eco-friendly adsorbent for successfully removing iron from leached geological matrices while maintaining a reasonable degree of reusability.
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supported by the National Key Research and Development Program of China(2022YFA1504402)National Energy R&D Center of Petroleum Refining Technology(RIPP,SINOPEC)+2 种基金the National Natural Science Foundation of China(22472016 and U23B20169)Key R&D Program of Ningbo(No.2023Z144)the Fundamental Research Funds for the Central Universities(DUT22LAB601).
文摘Desulfurization technology is rather difficult and urgently needed for carbon dioxide(CO_(2))utilization in industry.A new Cu(I)-based adsorbent was synthesized and examined for the capacity of removing carbonyl sulfide(COS)from a CO_(2)stream in an effort to solve the competitive adsorption between CO_(2)and COS and to seek opportunity to advance adsorption capacity.A wide range of character-ization techniques were used to investigate the physicochemical properties of the synthesized Cu(I)adsorbent featuringπ-complexation and their correlations with the adsorption performance.Meanwhile,the first principal calculation software CP2K was used to develop an understanding of the adsorption mechanism,which can offer useful guidance for the adsorbent regeneration.The synthesized Cu(I)adsorbent,prepared by using copper citrate and citric acid on the ZSM-5(SiO_(2)/Al_(2)O_(3)=25)carrier,outperformed other adsorbents with varying formulations and carriers in adsorption capacities.Through optimization of the preparation and adsorption conditions for various adsorbents,the breakthrough adsorption capacity(Qb)for COS was further enhanced from 2.19 mg/g to 15.36 mg/g.The formed stableπ-complex bonds between COS and Cu(I),as confirmed by density func-tional theory calculations,were verified by the significant improvement in the adsorption capacity after regeneration at 600°C.The above advantages render the novel synthesized Cu(I)adsorbent a promising candidate featuring cost-effectiveness,high efficacy and good regenerability for desulfurization from a CO_(2)stream.
基金supported by the National Natural Science Foundation of China(Nos.52100062,and 52230001)China Postdoctoral Science Foundation(No.2023M732785).
文摘This study introduced a microwave-assisted pyrolysis method for the rapid and efficientpreparation of boron-doped porous biochar. The resulting biochar exhibited a large specificsurface area (933.39 m^(2)/g), a rich porous structure (1.044 cm3/g), and abundant active sites.Consequently, the prepared boron-doped porous biochar exhibited higher efficiency in adsorbingtetracycline with a maximum adsorption capacity of 413.223 mg/g, which significantlyexceeded that of unmodified biochar andmost commercial and reported adsorbents.The correlation analysis between the adsorption capacity and adsorbent characteristics revealedthat the formation of the –BCO_(2) group enhanced π–π electron donor–acceptor interactionsbetween boron-doped porous biochar and tetracycline. This mechanism mainlycontributed to the enhanced adsorption of tetracycline by boron-doped porous biochar. Additionally,the as-prepared boron-doped porous biochar exhibited broad applications in removingantibiotics (tetracycline), phenolics (bisphenol A), and dyes (methylene blue andrhodamine B). Moreover, the boron-doped porous biochar exhibited satisfactory stability,and its adsorption capacity can be nearly completely regenerated through simple heat treatment.This study provides new insights into the effectiveness of boron-doped carbonaceousmaterials in removing antibiotic contaminants.
基金supported by the Scientific and Technological Innovation Project of Carbon Emission Peak and Carbon Neutrality of Jiangsu Province(No.BK20220001)the Big Data Computing Center of Southeast University.
文摘Sodium-based adsorbents(Na_(2)CO_(3)/γ-Al_(2)O_(3))exhibit significant potential for commercial utilization in CO_(2)capture.Nevertheless,the requirement for high desorption temperatures poses challenges in terms of the high-quality heat needed for desorption.This study integrated ZrO_(2)doping into a sodium-based adsorbent to enhance its CO_(2)capture performance and lower its desorption temperature.The research investigated the CO_(2)adsorption capacity,reaction rate,and desorption characteristics of the ZrO_(2)-doped Na_(2)CO_(3)/γ-Al_(2)O_(3)adsorbents in detail.Additionally,the catalytic mechanism of ZrO_(2)was elucidated through Density Functional Theory calculations.The results showed that ZrO_(2)doping increased the adsorption rate and capacity of the adsorbent and reduced the desorption energy consumption.Desorption reaction activation energy reduced to 44.8 kJ/mol.The adsorbent doped with 3wt.%ZrO_(2)demonstrated the highest adsorption capacity and rate under optimal conditions,with a reaction temperature of 45℃,an adsorption capacity of 1.66 mmol/g,and a carbon conversion rate of 80.2%.ZrO_(2)acted as a catalyst,enhancing CO_(2)and H_(2)O adsorption,and facilitated CO_(2)desorption in the sodium-based adsorbent by forming[ZrO(OH)]^(+)and OH^(−)through H_(2)O adsorption activation.The lower energy barrier(0.17 eV)for the dissociative adsorption pathway of H_(2)O molecules on the ZrO_(2)surface further supported the role of ZrO_(2)in enhancing the overall adsorption performance of the adsorbent in the carbon capture process.Ultimately,the ZrO_(2)-doped Na_(2)CO_(3)/γ-Al_(2)O_(3)adsorbent was identified as having low desorption energy consumption,high adsorption capacity,and rate,offering potential cost reductions in CO_(2)capture and representing a promising adsorbent for this application.
基金supported by the National Natural Science Foundation of China (No.52364022)the Natural Science Foundation of Guangxi Province,China (Nos.2023JJA160192 and 2021GXNSFAA220096)+1 种基金the Guangxi Science and Technology Major Project,China (No.AA23073018)the Guangxi Chongzuo Science and Technology Plan,China (No.2023ZY00503).
文摘With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.
基金financial supports from National Natural Science Foundation of China(No.22204169)Gansu Natural Science Foundation(Nos.23JRRA619,21JR7RA076)Scientific and Technological Program of Chengguan District,Lanzhou(No.2023JSCX0037)。
文摘A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.
基金funded by the Ministry of Science and Higher Education of the Republic of Kazakhstan(grant number AP19678142)。
文摘The goal of this work is,first of all,to construct a mathematical model of the mass transfer process in porous adsorption layers,taking into account the fact that in most cases the adsorption process is carried out in nonstationary technological modes,which requires a clear description of its various stages.The scientific contribution of the novel model is based on a probability approach allowing for deriving a differential equation that takes into account the diffusion migration of adsorbed particles.Solving this equation allows us to calculate the reduced degree of the adsorption surface coverage along the flow and,thereby,calculate the efficiency of the mass transfer process.The model also makes it possible to determine the slip coefficient,the internal diffusion coefficient and the degree of filling of the internal surface of the pores of the adsorbent layer,which corresponds to the completion of the initial stage of adsorption and the transition of the process to a stable mode.In this case,the problem is to calculate a non-isothermal turbulent boundary layer when flowing around the surface of an adsorbent.Next,the problem of identifying the main control parameters of the model has been solved.Based on such analysis and experimental studies to assess the influence of process control parameters,the patterns of adsorption purification and solution separation have been established and the design of a highly efficient adsorption apparatus with a fixed layer of porous adsorbent have been developed.
