adsorption mechanism

吸附机理
  • 文章类型: Journal Article
    锆金属-有机骨架MIP-202(Zr),基于L-天冬氨酸,通过水热法制备并用于研究水溶液中的钌吸附。用X射线衍射(XRD)对所得材料进行了表征,红外光谱(IR),热重分析(TGA),差示扫描量热法(DSC),扫描电镜(SEM)和X射线光电子能谱(XPS)。为了确定吸附平衡,进行了分批吸附实验,MIP-202(Zr)水溶液对Ru(III)的动力学和热力学参数。通过Langmuir拟合和分析了钌在MIP-202(Zr)上的吸附数据,Freundlich和Temkin平衡等温线模型,而Langumir吸附等温线模型拟合最好。通过四个动力学模型分析动力学数据,MIP202(Zr)上的钌吸附可以通过颗粒内扩散(WeberMorris)描述得最好。对MIP-202(Zr)上的钌离子吸附的热力学性质的分析表明,吸附过程具有自发和吸热性质,并且在能量上是有益的。
    The zirconium metal - organic framework MIP-202(Zr), based on L-aspartic acid, was prepared by hydrothermal method and used for study of ruthenium adsorption from aqueous solutions. The obtained material was characterized by X-ray diffraction (XRD), infra red spectroscopy (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The batch adsorption experiment was performed for determination of adsorption equilibrium, kinetics and thermodynamics parameters to Ru(III) from aqueous solution on MIP-202(Zr). The data of ruthenium sorption onto MIP-202(Zr) were fitted and analyzed by the Langmuir, Freundlich and Temkin equilibrium isotherm models, while the Langumir adsorption isotherm models fit the best. Kinetic data were analyzed by four kinetic models, and ruthenium sorption on MIP202(Zr) can be describes the best by intra particle diffusion (Weber Morris). Analysis of thermodynamic properties of ruthenium ions sorption onto MIP-202(Zr) shows that the sorption process has a spontaneous and endothermic nature and is energetically beneficial.
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  • 文章类型: Journal Article
    抗生素,作为新兴的持久性污染物,对人类健康构成重大威胁。高效、低成本地去除废水中的环丙沙星(CIP)已成为重要的研究热点。在这项研究中,以粉煤灰(FA)为原料,通过改变微波功率制备改性粉煤灰(MFA),碱浓度,和浸泡时间研究其对CIP的吸附特性结果表明,MFA的最佳制备条件对CIP的吸附最有效,使用Box-Behnken响应面方法,微波功率为480瓦,碱浓度为1.5mol/L,和3小时的改性时间。扫描电子显微镜,傅里叶变换红外光谱,和X射线衍射分析表明,改性后,FA的玻璃状结构被破坏,比表面积增加,并出现明显的羟基O-H吸收峰。FA和MFA均表现出符合拟二级动力学和Langmuir方程的CIP吸附过程。在pH=6时实现了CIP的最大吸附(9.61和12.67mg/g)。随着温度的升高,FA和MFA对CIP的吸附能力均下降,表示放热过程。ClP的吸附容量随离子浓度的增加而降低,离子的影响顺序为Al3+>Ca2+>Na+。结果表明,孔隙充填,静电相互作用,离子交换和络合是FA吸附CIP的主要途径。微波碱改性粉煤灰是一种经济高效的去除水中CIP的吸附剂,实现“用废物处理废物”的目的。本研究为控制CIP处理废水提供了科学依据。
    Antibiotics, as emerging persistent pollutants, pose significant threats to human health. The effective and low-cost removal of ciprofloxacin (CIP) from wastewater has become an important research focus. In this study, fly ash (FA) was used as the raw material, and modified fly ash (MFA) was prepared by varying microwave power, alkali concentration, and immersion time to investigate its adsorption characteristics for CIP. Results showed that the optimal preparation conditions for MFA with the most effective adsorption of CIP, using the Box-Behnken response surface methodology, were a microwave power of 480 W, an alkali concentration of 1.5 mol/L, and a modification time of 3 h. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analyses revealed that after modification, the glassy structure of FA is destroyed, the specific surface area is increased, and obvious hydroxyl O-H absorption peaks appear. Both FA and MFA exhibited adsorption processes for CIP that conformed to pseudo-second-order kinetics and the Langmuir equation. Maximum adsorption of CIP (9.61 and 12.67 mg/g) was achieved at pH = 6. With increasing temperature, the adsorption capacity of both FA and MFA for CIP decreased, indicating an exothermic process. The adsorption capacity of CIP decreased with increasing ion concentration, with the impact order of ions being Al3+  > Ca2+  > Na+. The results show that pore filling, electrostatic interaction, ion exchange and complexation are the main ways of CIP adsorption by FA. Microwave alkali modified fly ash is an economical and efficient adsorbent for CIP removal in water, realizing the purpose of \"treating waste with waste\". This study provides a scientific basis for controlling CIP treatment in wastewater.
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  • 文章类型: Journal Article
    微塑料(MPs)作为污染物载体的作用及其对有机污染物命运的影响已引起广泛关注。然而,MPs对酰胺类除草剂在土壤中吸附的影响,没有被调查。在这项研究中,不可生物降解(聚乙烯,PEM)和可生物降解(聚己二酸对苯二甲酸丁二醇酯,PBATM)MPs通过暴露于一个月的紫外线照射而老化。通过批量实验研究了MPs对两种农业土壤(黑土[BS]和潮土[CS])中萘丙酰胺(Nap)吸附的影响。结果表明,Nap在PEM上的吸附主要受物理过程控制,while,化学机制,在PBATM上不应该被忽视。加上0.2%的议员,含PEM(土壤-PEM)土壤的最大吸附容量(Qm)和吸附分配系数(KF)均高于土壤-PBATM,然而,当MPs的添加量为2%时,Nap的土壤-PBATM的Qm和KF值较高。紫外线老化后,MP的比表面积增加导致土壤颗粒的附着力增加。这些归因于不同(老化)MP的不同表面性质和浓度,导致土壤颗粒的抑制作用不同。通过X射线光电子能谱证实了土壤颗粒的粘附。此外,不管议员的加入,Nap的BSQm值高于CS。总之,MPs可以改变Nap在土壤中的吸附,影响其在土壤生态系统中的移动性和环境风险。
    The role of microplastics (MPs) as pollutant carriers and their influence on the fate of organic pollutants has received considerable attention. However, the impacts of MPs on the adsorption of amide herbicides in soil, have not been investigated. In this study, non-biodegradable (polyethylene, PEM) and biodegradable (polybutylene adipate terephthalate, PBATM) MPs were aged by exposure to one month of ultraviolet irradiation. The impacts of MPs on the adsorption of napropamide (Nap) in two agricultural soils (black soil [BS] and fluvo-aquic soil [CS]) were investigated through batch experiments. The findings suggested that the adsorption of Nap onto PEM was mainly governed by physical processes, while, chemical mechanisms, should not be overlooked on PBATM. With the addition of 0.2% MPs, the maximum adsorption capacity (Qm) and adsorption distribution coefficient (KF) of soil containing PEM (soil-PEM) were higher than that of soil-PBATM, however, the Qm and KF values of soil-PBATM for Nap were higher when the addition of MPs was 2%. After UV aging, the increased specific surface area of MPs led to an increased adhesion of soil particles. These were attributed to the different surface properties and concentrations of different (aged) MPs, resulting in differences in the inhibition effect by soil particles. The adhesion of soil particles was confirmed by X-ray photoelectron spectroscopy. Additionally, regardless of the addition of MPs, the Qm values of BS for Nap were higher than those for CS. In summary, MPs can alter the adsorption of Nap in soil, influencing both its mobility within the soil ecosystem and the environmental risk.
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  • 文章类型: Journal Article
    使用生物炭处理染料废水由于其优异的吸附性能和低成本而引起了人们的兴趣。在这项工作中,一种来自土霉素发酵残渣的新型生物炭(功能化OFR生物炭,FOBC)作为典型染料去除的有效吸附剂进行了研究。在25°C时,用FOBC-3-600的Langmuir模型计算的亚甲基蓝(MB)的最大吸附容量,孔雀石绿(MG),甲基橙(MO)达到643.97、617.89和521.03mg/g,分别。动力学和等温线模型拟合表明,化学吸附和物理吸附均发生在吸附过程中。染料通过孔隙填充被有效吸附,静电吸引,π-π相互作用,和表面络合。循环实验和环境风险评估表明,FOBC-3-600具有优异的可回收性和使用安全性。总的来说,本研究提供了一种同时处理印染废水和利用抗生素发酵残渣的实用方法。
    Using biochar for dye wastewater treatment is attracting interest due to its excellent adsorption properties and low costs. In this work, a novel biochar derived from oxytetracycline fermentation residue (functionalized OFR biochar, FOBC) was investigated as a efficient adsorbent for typical dyes removal. At 25 °C, the maximum adsorption capacity calculated by Langmuir model of FOBC-3-600 for methylene blue (MB), malachite green (MG), and methyl orange (MO) reached 643.97, 617.89, and 521.03 mg/g, respectively. The kinetics and isotherm model fitting showed that the chemisorption and physisorption both occurred during the adsorption process. Dyes were efficiently adsorbed through pore filling, electrostatic attraction, π-π interactions, and surface complexation. And the cycling experiment and environmental risk assessment indicated that the FOBC-3-600 had excellent recyclability and utilization safety. Overall, this study provides a practical method to simultaneously treat the dyeing wastewater and utilize the antibiotic fermentation residue.
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  • 文章类型: Journal Article
    由于戊唑醇对水生生态系统的严重威胁,开发高效吸附材料对戊唑醇污染水体的可持续修复势在必行。在这里,通过一步热解从玉米秸秆和H3PO4中制备了磷(P)掺杂的生物炭,用于戊唑醇吸附。结果表明,在500℃下生产的P掺杂生物炭(PBC500)具有较大的比表面积(SSA=869.6m2/g),丰富的表面官能团,戊唑醇的吸附量最高(429.6mg/g)。戊唑醇在PBC500上的吸附遵循拟二级动力学和Langmuir吸附等温线模型。热力学计算表明,PBC500对戊唑醇的吸附是自发的,吸热过程随机增加。吸附机理主要涉及孔隙充填,π-π相互作用,氢键,和疏水相互作用。此外,PBC500在从不同水源中吸附戊唑醇方面表现出强大的抗干扰能力,并表现出出色的可重用性,强调了它在广泛的实际应用中的潜力。
    Due to the serious threat posed by tebuconazole to the aquatic ecosystem, it is imperative to develop a highly efficient adsorbent material for the sustainable remediation of tebuconazole-contaminated water. Herein, a phosphorus (P)-doped biochar from corn straw and H3PO4 was fabricated by one-step pyrolysis for tebuconazole adsorption. Results showed that the P-doped biochar produced at 500℃ (PBC500) possesses a large specific surface area (SSA=869.6 m2/g), abundant surface functional groups, and the highest tebuconazole adsorption capacity (429.6 mg/g). The adsorption of tebuconazole on PBC500 followed pseudo-second-order kinetics and Langmuir adsorption isotherm models. Thermodynamic calculations indicated that the adsorption of tebuconazole by PBC500 was a spontaneous, endothermic process with a random increase. Adsorption mechanism mainly involves pore filling, π-π interactions, hydrogen bonding, and hydrophobic interaction. Moreover, PBC500 demonstrated robust anti-interference capabilities in adsorbing tebuconazole from diverse water sources and exhibited excellent reusability, underscoring its potential for a broad array of practical applications.
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  • 文章类型: Journal Article
    除了过滤一些沉积物,疏水性木材海绵还可以吸收许多有机溶剂,特别是原油。原油泄漏对海洋生态系统构成严重威胁,油与水混合也会对其使用产生很大的危险。从低成本和高性能的角度来看,木质海绵在处理原油污染方面表现出巨大的潜力。木材海绵是一种可再生材料。具有高度定向的层状结构和高度可压缩的三维多孔框架,木海绵是非常疏水的,使它们成为油水分离的理想选择。目前,制造木材海绵的最常见方法是首先破坏木材细胞壁以获得多孔取向的层状结构,然后通过超疏水处理增强油水分离能力。使用各种实验方法和不同天然木材制备的木材海绵在坚固性方面表现出独特的特性,可压缩性,抗疲劳性,和吸油能力。作为气凝胶材料,木材海绵提供多种作用(吸收,过滤)和可重复使用的油水分离功能。本文介绍了使用木质海绵进行油水分离的优点。解释了木材海绵的理化性质及其吸附原油的机理。讨论了合成方法和性能。最后,对木材海绵的使用进行了总结和展望。
    In addition to filtering some sediments, hydrophobic wood sponges can also absorb many organic solvents, particularly crude oil. The leakage of crude oil poses a serious threat to the marine ecosystem, and oil mixed with water also generates great danger for its use. From the perspective of low cost and high performance, wood sponges exhibit great potential for dealing with crude oil pollution. Wood sponge is a renewable material. With a highly oriented layered structure and a highly compressible three-dimensional porous frame, wood sponges are extremely hydrophobic, making them ideal for oil-water separation. Currently, the most common approach for creating wood sponge is to first destroy the wood cell wall to obtain a porous-oriented layered structure and then enhance the oil-water separation ability via superhydrophobic treatment. Wood sponge prepared using various experimental methods and different natural woods exhibits distinctive properties in regards to robustness, compressibility, fatigue resistance, and oil absorption ability. As an aerogel material, wood sponge offers multi-action (absorption, filtration) and reusable oil-water separation functions. This paper introduces the advantages of the use of wood sponge for oil-water separation. The physical and chemical properties of wood sponge and its mechanism of adsorbing crude oil are explained. The synthesis method and the properties are discussed. Finally, the use of wood sponge is summarized and prospected.
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  • 文章类型: Journal Article
    为了提高浮选效率,对低品位氧化锌矿进行了硫化,但预硫化对十八烷基胺(ODA)在菱镁矿表面吸附机理的影响目前尚不清楚。在这项研究中,以锌矿和预硫化锌矿为样品,通过zeta电位研究了预硫化对ODA吸附机理和浮选行为的影响,接触角测量,总有机碳分析仪(TOC),石英微晶天平(QCM),傅里叶变换红外光谱(FTIR),X射线光电子能谱(XPS),和微浮选试验。微浮选试验表明,硫化预处理可以提高锌矿的可浮性。Zeta电位和接触角测量表明,预硫化有利于ODA的吸附,使用TOC和QCM对ODA的吸附测试进一步证实了这一点。此外,FTIR和XPS分析表明,预硫化改变了ODA的吸附方式,将其从物理吸附转变为化学吸附。这些结果表明,预硫化对ODA的吸附和锌矿浮选的有利影响可能为工业应用提供重要指导。
    The low-grade zinc oxide ore was sulfidized to increase the efficiency of flotation, but the effect of pre-sulfidization on the adsorption mechanism of octadecyl amine (ODA) on the smithsonite surface is currently unclear. In this study, the effect of pre-sulfidization on the adsorption mechanism of ODA and the flotation behavior was studied using smithsonite and pre-sulfidized smithsonite as the samples by zeta potential, contact angle measurement, total organic carbon analyzer (TOC), quartz microcrystalline balance (QCM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and micro-flotation tests. Micro-flotation tests showed that the pretreatment of sulfidization could improve the floatability of smithsonite. Zeta potential and contact angle measurements demonstrated that pre-sulfidization could favor the adsorption of ODA, which is further confirmed by the adsorption tests of ODA using TOC and QCM. Furthermore, FTIR and XPS analysis showed that pre-sulfidization changes the adsorption mode of ODA, changing it from physical adsorption to chemical adsorption. These results suggested that the favorable effect of pre-sulfidization on the adsorption of ODA and the flotation of smithsonite might provide important guidance for industrial application.
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  • 文章类型: Journal Article
    在这项研究中,以铅锌(Pb-Zn)尾矿酸浸渣(APR)为原料,采用高温碱熔技术制备了高硅(Si)吸附剂(APR@Sam)。将合成的Si基材料应用于受Pb和镉(Cd)污染的水溶液中,以研究活性Si在螯合重金属中的关键作用。研究了APR@Sam和硅贫化材料(APR@Sam-NSi)在不同pH和温度条件下的吸附能力。结果表明,随着pH值从3增加到7,吸附量增加,溶液中的活性硅含量增加了63%,吸附后溶液的最大pH为7.12。去除活性Si后,APR@Sam对Pb(II)和Cd(II)的吸附量分别下降了45%和11.96%,分别。OH-促进Si释放到溶液中,提高材料的吸附效率。反应机理主要归因于由Si-O和Si-O-Si键引导的表面络合。金属阳离子交换,和整体协调。结果表明,Si成分对于APR@Sam去除Pb(II)和Cd(II)至关重要,并为浸出残留物的资源回收策略提供了有价值的见解。
    In this study, a high-Si (Si) adsorbent (APR@Sam) was prepared by acid leaching slag (APR) from lead-zinc (Pb-Zn) tailings based on high-temperature alkali melting technology. The synthesized Si-based materials were applied to aqueous solutions contaminated with Pb and cadmium (Cd) to investigate the crucial role of active Si in sequestering heavy metals. The adsorption capacities of APR@Sam and the Si-depleted material (APR@Sam-NSi) were studied under different pH and temperature conditions. The results showed that as the pH increased from 3 to 7, the adsorption capacity increased, the active Si content in the solution increased by 63 %, and the maximum pH of the solution after adsorption was 7.12. After the removal of active Si, the Pb (II) and Cd (II) adsorption capacities of APR@Sam decreased by 45 % and 11.96 %, respectively. OH- promoted the release of Si into the solution, enhancing the material\'s adsorption efficiency. The reaction mechanism is mainly attributed to surface complexation guided by Si-O and Si-O-Si bonds, metal cation exchange, and bidentate coordination. The results indicated that the Si component is critical for the removal of Pb (II) and Cd (II) by APR@Sam and provide valuable insights into resource recovery strategies from leaching residues.
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  • 文章类型: Journal Article
    在水处理过程中,氯化和紫外线(UV)灭菌可以改性微塑料(MPs)并改变其理化性质,导致国会议员和其他污染物之间的各种变化。在这项研究中,研究了氯化和紫外改性对聚苯乙烯(PS)和聚氯乙烯(PVC)理化性能的影响,并考察了改性前后培氟沙星(PEF)的吸附行为。pH的影响,离子强度,溶解的有机物,揭示了重金属离子等水环境条件对吸附行为的影响。结果表明,PS对PEF的吸附能力高于PVC,修饰增加了MP中含O官能团的存在,从而提高两种材料的吸附能力。氯化对MPs的理化性质的影响比紫外线照射在相同的时间内,导致更好的氯化吸附性能。发现吸附的最佳pH为6,NaCl,海藻酸钠和Cu2+会不同程度地抑制吸附,其中pH引起的抑制作用最强。氯化和紫外改性会削弱环境因素对MPs吸附PEF的抑制作用。吸附的主要机制涉及静电相互作用和氢键。研究阐明了改性对MPs理化性质的影响,为后续生物毒性分析和环境保护研究提供参考。
    During the water treatment process, chlorination and ultraviolet (UV) sterilization can modify microplastics (MPs) and alter their physicochemical properties, causing various changes between MPs and other pollutants. In this study, the impact of chlorination and UV modification on the physicochemical properties of polystyrene (PS) and polyvinyl chloride (PVC) were investigated, and the adsorption behavior of pefloxacin (PEF) before and after modification was examined. The effect of pH, ionic strength, dissolved organic matter, heavy metal ions and other water environmental conditions on adsorption behavior was revealed. The results showed that PS had a higher adsorption capacity of PEF than PVC, and the modification increased the presence of O-containing functional groups in the MPs, thereby enhancing the adsorption capacity of both materials. Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period, leading to better adsorption performance of chlorination. The optimal pH for adsorption was found to be 6, and NaCl, sodium alginate and Cu2+ would inhibit adsorption to varying degrees, among which the inhibition caused by pH was the strongest. Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs. The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding. The study clarified the effects of modification on the physicochemical properties of MPs, providing reference for subsequent biotoxicity analysis and environmental protection studies.
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  • 文章类型: Journal Article
    这项研究的目的是开发和评估壳聚糖接枝共聚物/HZSM5沸石席夫碱纳米纤维,用于从水性介质中吸附Cu2和Zn2。通过静电纺丝制备了纳米纤维,并使用XRD对其进行了表征,FTIR,1HNMR,FESEM,TGA,BET,和XPS。该研究评估了未修饰的HZSM5和席夫碱官能化对吸附能力的影响。在壳聚糖接枝共聚物中加入10.0wt%的沸石席夫碱作为最佳含量,显着增强了吸附,Zn2+和Cu2+分别增加98.2%和42.2%。具体来说,Zn2+吸附量从27.6mg/g增加到54.7mg/g,和Cu2+从67.1到95.4mg/g。温度等因素,pH值,吸附时间,和初始阳离子浓度进行了分析。动力学研究揭示了双指数模型,等温线分析表明与Redlich-Peterson模型非常吻合,显示Cu2+的最大单层容量为310.1mg/g,Zn2+的最大单层容量为97.8mg/g(pH6.0,240分钟,45°C)。吸附热力学表明自发和吸热吸附。可重复使用性测试显示五个循环后的最小容量损失(Cu2+为4.91%,Zn2+为5.59%)。纳米纤维在多离子系统和实际电镀废水中对Cu2+比Zn2+显示出更高的选择性,突出了其有针对性的重金属去除潜力。
    The objective of this research was to develop and assess chitosan-grafted copolymer/HZSM5 zeolite Schiff base nanofibers for Cu2+ and Zn2+ adsorption from aqueous media. Nanofibers were prepared via electrospinning and characterized using XRD, FTIR, 1H NMR, FESEM, TGA, BET, and XPS. The study evaluated the effect of unmodified HZSM5 and Schiff base functionalization on adsorption capacities. Incorporating 10.0 wt% zeolite Schiff base as the optimum content into the chitosan-grafted copolymer significantly enhanced adsorption, achieving increases of 98.2 % for Zn2+ and 42.2 % for Cu2+. Specifically, Zn2+ adsorption increased from 27.6 to 54.7 mg/g, and Cu2+ from 67.1 to 95.4 mg/g. Factors such as temperature, pH, adsorption time, and initial cation concentration were analyzed. Kinetic studies revealed a double-exponential model, and isotherm analysis indicated a good fit with the Redlich-Peterson model, showing maximum monolayer capacities of 310.1 mg/g for Cu2+ and 97.8 mg/g for Zn2+ (pH 6.0, 240 min, 45 °C). The adsorption thermodynamics indicated a spontaneous and endothermic adsorption. Reusability tests showed minimal capacity loss (4.91 % for Cu2+ and 5.59 % for Zn2+) after five cycles. The nanofiber displayed greater selectivity for Cu2+ over Zn2+ in multi-ion systems and real electroplating wastewater, highlighting its potential for targeted heavy metal removal.
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