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1.
A novel biosorbent was developed by coating chitosan,a naturally and abundantly available biopolymer,on to activated alumina based on oil shale ash via crosslinking.The adsorbent was characterized by various techniques,such as Fourier transform infrared spectroscopy,scanning electron microscopy,thermogravimetric-differential thermal analysis,and X-ray photoelectron spectroscope.Batch isothermal equilibrium adsorption experiments were condcted to evaluate the adsorbent for the removal of Cu(Ⅱ) from wastewater.The effect of pH and agitation time on the adsorption capacity was also investigated,indicating that the optimum pH was 6.0.The equilibrium adsorp-tion data were correlated with Langmuir and Freundlich models.The maximum monolayer adsorption capacity of chitosan coated alumina sorbent as obtained from Langmuir adsorption isotherm was found to be 315.46 mg·g-1 for Cu(Ⅱ).The adsorbent loaded with Cu(Ⅱ) was readily regenerated using 0.1 mol?L?1 sodium hydroxide solution.All these indicated that chitosan coated alumina adsorbent not only have high adsorption activity,but also had good stability in the wastewater treatment process.  相似文献   

2.
Adsorption processes have received special attention for contaminants removal thanks to their capability to generate effluents with high quality as well as their simple design. In the current work, the agro-waste residue avocado peel is proposed to be used as alternative to conventional activated carbons whose use is sometimes restricted to high costs, upgraded by their exhausting after long term operations. The carbonization procedure was optimized and analyzed through factorial design and response surface methodology by evaluating temperature(400–900 °C) and time(30–90 min) effects: optimal conditions were found at 900 °C and 65 min, generating an adsorbent with 87.52 m2·g-1of BET surface area, a mesopore volume of 74% and a zero point charge at 8.6. The feasibility of the carbonaceous material was proved for the removal of a variety of dyes by investigating substrate(10–50 mg·L-1) and solid(0.5–20 g·L-1) concentration effects and statistical significance: complete removal of Naphthol Blue Black and Reactive Black 5 was reached under optimal conditions(10 mg·L-1and20 g·L-1of dye and solid, respectively), while Basic Blue 41 was eliminated by using 13.4 g·L-1of the adsorbent.Overall, dyes removal by adsorption on carbonized avocado peel is presented as a promising technology due to the low cost and easy availability of the precursor, as well as the straightforward generation, the satisfactory characteristics and the proved adsorption capacity of the adsorbent.  相似文献   

3.
In present study,we report the preparation of coconut shell activated carbon as adsorbent and its appli-cation for Bi(Ⅲ) removal from aqueous solutions.The developed adsorbent was characterized with scanning elec-tron microscope(SEM),Fourier Transform Infrared(FTIR),C,H,N,S analyzer,and BET surface area analyzer.The parameters examined include agitation time,initial concentration of Bi(Ⅲ),adsorbent dose and temperature.The maximum adsorption of Bi(Ⅲ)(98.72%) was observed at 250 mg·L-1 of Bi(Ⅲ) and adsorbent dose of 0.7 g when agitation was at 160 r·min-1 for 240 min at(299±2) K.The thermodynamic parameters such as Gibb’s free energy(△Gθ),enthalpy(△Hθ) and entropy(△Sθ) were evaluated.For the isotherm models applied to adsorption study,the Langmuir isotherm model fits better than the Freundlich isotherm.The maximum adsorption capacity from the Langmuir isotherm was 54.35 mg?g?1 of Bi(Ⅲ).The kinetic study of the adsorption shows that the pseudo second order model is more appropriate than the pseudo first order model.The result shows that,coconut shell ac-tivated carbon is an effective adsorbent to remove Bi(Ⅲ) from aqueous solutions with good adsorption capacity.  相似文献   

4.
Metal ion contamination of drinking water and waste water, especially with heavy metal ion such as lead, is a serious and ongoing problem. In this work, activated carbon prepared from peanut shell (PAC) was used for the removal of Pb^2+ from aqueous solution. The impacts of the Pb25 adsorption capacities of the acid-modified carbons oxidized with HNO3 were also investigated. The surface functional groups of PAC were confirmed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Boehm titration. The textural properties (surface area, total pore volume) were evaluated from the nitrogen adsorption isotherm at 77 K. The experimental results presented indicated that the adsorption data fitted better with the Langmuir adsorption model. A comparative study with a commercial granular activated carbon (GAC) showed that PAC was 10.3 times more efficient compared to GAC based on Langmuir maximum adsorption capacity. Further analysis results by the Langmuir equation showed that HNO3 [20% (by mass)] modified PAC has larger adsorption capacity of Pb^2+ from aqueous solution (as much as 35.5 mg·g^-1). The adsorption capacity enhancement ascribed to pore widening, increased cation-exchange capacity by oxygen groups, and the promoted hydrophilicity of the carbon surface.  相似文献   

5.
A new nanometer material, nanometer AlO(OH) loaded on the fiberglass with activated carbon fibers felt(ACF) as the carrier, was prepared by hydrolytic reaction for the removal of Cd(II) from aqueous solution using column adsorption experiment. As was confirmed by XRD determination, the hydrolysis production loaded on fiberglass was similar to the orthorhombic phase AlO(OH). SEM images showed that AlO(OH) particles were in the form of small aggregated clusters. The Thomas model was applied for estimating the kinetic parameters and the saturated adsorption ability of Cd(II) adsorption on the new adsorbent. The results showed that the maximum adsorption capacity of Cd(II) was 128.50 mg·g^-1 and 117.86 mg·g^-1 for the adsorbent mass of 0.3289 g and the adsorbent mass of 0.2867 g, respectively. The elution experiment result indicated that the adsorbed Cd ions was easily desorbed from the material with 0.1 mol·L^-1 HCl solution. Adsorption-desorption cycles showed the feasibility of repealed uses of the composited material. The adsorption capacities were influenced by pH and the initial Cd(II) concentration. The amount adsorbed was greatest at pH 6.5 and the initial Cd(II) concentration of 0.07 mg·L^-1, respectively. Nanometer AlO(OH) played a major role in the adsorption process, whereas the fiberglass and ACF were assistants in the process of removing Cd(II). In addition, the adsorption capacities for Cd(II) were obviously reduced from 128.50 mg·L^-1 to 64.28 mg·L^-1 when Pb ions were present because Pb ions took up more adsorption sites.  相似文献   

6.
Magnetic starch microspheres(AAM-MSM) were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS) as a crude material, acrylic acid(AA) and acrylamide(AM) as graft copolymer monomers, and methyl methacrylate(MMA) as the dispersing agent and used as an adsorbent for the removal of Cd(II) ions from aqueous solution. Fourier-transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), and vibrating sample magnetometry(VSM) were used to characterize the AAM-MSM adsorbent. The results indicated that AA, AM, and MMA were grafted to the MS, and the Fe_3 O_4 nanoparticles were encapsulated in the AAM-MSM adsorbent microspheres.The adsorbent exhibited a smooth surface, uniform size, and good sphericity because of the addition of the MMA and provided more adsorption sites for the Cd(II) ions. The maximum adsorption capacity of Cd(II) on the AAM-MSM was 39.98 mg·g~(-1). The adsorbents were superparamagnetic, and the saturation magnetization was 16.7 A·m~2·kg~(-1). Additionally, the adsorption isotherms and kinetics of the adsorption process were further investigated. The process of Cd(II) ions adsorbed onto the AAM-MSM could be described more favorably by the pseudo-second-order kinetic and Langmuir isothermal adsorption models, which suggested that the chemical reaction process dominated the adsorption process for the Cd(II) and chemisorption was the rate-controlling step during the Cd(II) removal process.  相似文献   

7.
Effective recovery of UO2+2 from wastewater is essential for nuclear fuel industry and related industries.In this study,a novel adsorbent was prepared by loading titanium(Ti4+) onto collagen fiber(TICF),and its physical and chemical properties as well as adsorption to UO2+2 in nuclear fuel industrial wastewater were investigated.It is found that TICF can effectively recover UO2+2 from the wastewater with excellent adsorption capacity.The adsorption capacity is 0.62 mmol·g-1 at 303 K and pH 5.0 when the initial concentration of UO2+2 is 1.50 mmol·L-1.The adsorption isotherms can be described by the Langmuir equation and the adsorption capacity increases with temperature.The effect of co-existed F on the adsorption capacity for UO2+2 is significant,which can be eliminated by adding aluminum ions as complexing agent,while the other co-existed ions in the solutions,including HCO-3,Cl-,NO-3,Ca2+,Mg2+ and Cu2+,have little effect on the adsorption capacity for UO2+2.The saturated TICF after UO2+2 adsorption can be regenerated by using 0.2 mol·L-1 nitrate(HNO-3) as desorption agent,and the TICF can be reused at least three times.Thus the TICF is a new and effective adsorbent for the recovery of UO2+2 from the wastewater.  相似文献   

8.
A low-cost adsorbent was prepared from sludge and straw by pyrolysis in a dried state with the surface area of the adsorbent of 829.49 ma. g-l, micropore volume of 0.176 cm2·g-1 and average pore radius of 5.0 nm. The kinetic, equilibrium isotherm and thermodynamic characteristics of trisodium 1-(1-naphthylazo)-2-hydroxynaphthalene- 4',6,8-trisulphonate (acid scarlet 3R) onto the adsorbent from sludge and straw were investigated. The results indicated that the pseudo second order adsorption was the predominant adsorption mechanism of acid scarlet 3R. Thus, the adsorption phenomenon was suggested as a chemical process. The adsorption data were fitted better with Langmuir model than Freundlich model, indicating that the adsorption of acid scarlet 3R belonged to the monolayer adsorption and mainly occurred in micropores.  相似文献   

9.
Adsorption is an important process in wastewater treatment,and conversion of waste materials to adsorbent offers a solution to high material cost related to the use of commercial activated carbon.This study investigated the adsorption behaviour of Reactive Black 5(RB5)and methylene blue(MB)onto activated carbon produced from textile sludge(TSAC).The activated carbon was synthesized through chemical activation of precursor followed with carbonization at 650°C under nitrogen flow.Effects of time(0–200 min),pH(2–10),temperature(25–60°C),initial dye concentration(0–200 mg·L~(-1)),and adsorbent dosage(0.01–0.15 g)on dye removal efficiency were investigated.Preliminary screening revealed that TSAC synthesized via H_2SO_4activation showed higher adsorption behaviour than TSAC activated by KCl and ZnCl_2.The adsorption capacity of TSAC was found to be 11.98 mg·g~(-1)(RB5)and 13.27 mg·g~(-1)(MB),and is dependent on adsorption time and initial dye concentration.The adsorption data for both dyes were well fitted to Freundlich isotherm model which explains the heterogeneous nature of TSAC surface.The dye adsorption obeyed pseudo-second order kinetic model,thus chemisorption was the controlling step.This study reveals potential of textile sludge in removal of dyes from aqueous solution,and further studies are required to establish the applicability of the synthesized adsorbent for the treatment of waste water containing toxic dyes from textile industry.  相似文献   

10.
Adsorption capacity of activated carbon prepared from spent tea leaves(STL-AC) for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with phosphoric acid(H_3PO_4) increased removal efficiency of STL-AC. Characterizations on STL-AC revealed excellent textural properties(1200 m~2·g~(-1), 51% mesoporosity), as well as distinctive surface chemistry(1.08 mmol·g~(-1) and 0.54 mmol·g~(-1) for acidic and basic oxygenated groups, pH_(pzc)= 2.02). Maximum removal efficiency of aspirin observed was 94.28% after 60 min when the initial concentration was 100 mg·L~(-1), 0.5 g of adsorbent used,pH 3 and at a temperature of 30 ℃. The adsorption data were well fitted to the Freundlich isotherm model and obeyed the pseudo-second order kinetics model. The adsorption of aspirin onto STL-AC was exothermic in nature(ΔH~Θ=~(-1)3.808 k J·mol~(-1)) and had a negative entropy change, ΔS~Θ(-41.444 J·mol~(-1)). A negative Gibbs free energy, ΔG~Θ was obtained indicating feasibility and spontaneity of the adsorption process. The adsorption capacity of AC-STL(178.57 mg·g~(-1)) is considerably high compared to most adsorbents synthesized from various sources, due to the well-defined textural properties coupled with surface chemistry of STL-AC which favors aspirin adsorption. The results demonstrate the potential of STL-AC as aspirin adsorbent.  相似文献   

11.
This research demonstrates the production of mesoporous activated carbon from sargassum fusiforme via physical activation with carbon dioxide. Central composite design was applied to conduct the experiments at different levels by altering three operating parameters. Activation temperature(766–934 ℃), CO_2 flow rate(0.8–2.8 L·min(~-1)) and activation time(5–55 min) were the variables examined in this study. The effect of parameters on the specific surface area, total pore volume and burn-out rate of activated carbon was studied,and the influential parameters of methylene blue adsorption value were identified employing analysis of variance. The optimum conditions for maximum methylene blue adsorption value were: activation temperature = 900 ℃, activation time = 29.05 min and CO_2 flow rate = 1.8 L·min(~-1). The activated carbon produced under optimum conditions was characterized by BET, FTIR and SEM. The adsorption behavior on congo red was studied. The effect of parameters on the adsorbent dosage, temperature, PH and initial congo red concentration was investigated. The adsorption properties of the activated carbon were investigated by kinetics. The equilibrium removal rate and maximum adsorption capacity reaches up to 94.72%, 234 mg·g-1,respectively when initial congo red concentration is 200 mg·L~(-1) under adsorbent dosage(0.8 g · L~(-1)),temperature(30℃), PH7.  相似文献   

12.
Herein, we develop cost-efficient superhigh-performance of engineering carbonaceous adsorbent from cigarette butts using combined wet-impregnated and re-dispersed method of KOH, which optimizes the implant approach of activator, breaking the restriction of selective capture of toluene using traditional activated carbon. The Brunauer-Emmett-Teller (BET) surface area and pore volume of targeted adsorbent can attain 3088 m2·g-1 and 1.61 cm3·g-1, respectively, by optimizing the temperature-dependent synthetic factor effect of the adsorbent. The adsorption capacity of resultant adsorbent for presenting volatile benzene and toluene shows a positive correlation with increasing carbonization temperature of carbon precursor. Besides, we demonstrated the unsmoked and smoked butts derived adsorbents afford feeble difference in saturated adsorbed capacity of volatile organic compounds (VOCs). The highest adsorption capacity of sample CF-800 for benzene and toluene in CF group is as high as 1268.1 and 1181.6 mg·g-1 respectively, slightly higher than that of sample UF-800, but far outperforming reported other adsorbents. The predicted adsorption selectivity of CF-800 and UF-800 for C7H8/H2O (g) using the DIH (difference of isosteric heats) equation reach up to ca. 3800 and 7500 respectively, indicating the weak adsorbability of water vapor on the developed adsorbent and greater superiority of the smoked butts derived adsorbents in selective capture of VOCs at low relative humidity in the competitive adsorption process for practical mixed VOCs.  相似文献   

13.
Ultra-deep desulfurization of transformer oil is of great demand among power industry. In this work, the effective and deep removal of various types of organosulfurs, including mercaptan, sulfide and disulfide via catalytic adsorptive desulfurization (CADS) using bifunctional Ti-based adsorbent is reported. Compared to adsorptive desulfurization (ADS), dramatically improvement of the organosulfur uptakes were achieved under CADS process. The equilibrium adsorption capacity at 5 μg·g-1 S reached up to 15.7, 33.4, 11.6 and 11.9 mg·g-1 for propyl mercaptan(n-PM), dimethyl sulfide(DMS), di-t-butyl disulfide (DTBDS) and dibenzyl disulfide (DBDS), which was 262, 477, 97 and 128 times to that of ADS process, respectively, and was the highest among the reported desulfurization adsorbents. Moreover, it achieved superior breakthrough capacity of 2050, 530 and 210 ml F·(g A)-1 at the breakthrough S concentration of 1 μg·g-1 of the commercial transformer oil S containing 10, 50 and 150 μg·g-1, respectively. The effectiveness of CADS is associated to the transformation of sulfur species to higher polar sulfonic species with the assistance of mild oxidant, which can be readily captured by silanol groups on SiO2 through H-bonding interaction. The excellent recyclability of the adsorbent can be realized through solvent washing or oxidative air treatment. This work provides an effective and economic approach for the elimination of trace amount of mercaptan, sulfide and disulfide from transformer oil.  相似文献   

14.
以γ-Al_2O_3为主要组成,添加质量分数2%~5%的Cu O、2%~5%的Zn O和1%~2%Mo O_3,采用盘式造粒成型工艺制备(2~3)mm的球形颗粒,通过烘干和焙烧制备出比表面积(200~250)m~2·g~(-1)的载体,然后用碱金属氢氧化物对载体进行修饰,制得COS吸附剂,并考察其对COS的吸附性能。结果表明,通过添加活性氧化物的产品对COS的吸附性能良好,对COS吸附容量达11.5 mg·g~(-1),可将COS脱除至0.02 mg·m~(-3)。  相似文献   

15.
水稻秸秆蒸汽爆破-酯化改性制备吸油材料   总被引:2,自引:0,他引:2       下载免费PDF全文
以水稻秸秆为原料进行蒸汽爆破-酯化改性制备溢油吸附材料。未改性水稻秸秆有一定的吸油能力,其饱和吸油倍率、吸水倍率分别为5.66 g·g-1,7.59 g·g-1。通过对水稻秸秆进行蒸汽爆破-酯化改性后,发现其亲油疏水性能得到显著改善。对酯化反应的影响因素进行系统考察,得到优化的改性条件为反应温度为80℃,催化剂对甲基苯磺酸酐浓度为0.75%,反应时间为6 h。改性后水稻秸秆吸油倍率为8.54 g·g-1,吸水倍率为0.10 g·g-1。对蒸汽爆破-酯化改性前后水稻秸秆材料进行BET、XRD以及FT-IR表征,发现爆破处理后材料的孔径增大;非结晶态以及乙酰基特征峰的出现说明水稻秸秆发生酯化改性反应。  相似文献   

16.
配制了将不同含量的多壁碳纳米管(MWCNT)加入复合吸附剂13X/MgCl2中制成的新型复合吸附剂,并对其吸附、脱附和导热性能进行了测试。实验结果表明:新型复合吸附剂在闭式200℃脱附完成后,新型复合吸附剂的吸附残余量随着MWCNT含量的升高而减小,13X的吸附残余量是MWCNT含量最高的13X/MgCl2/MWCNT(CNT-5)复合吸附剂的吸附残余量的2倍,虽然MWCNT的加入不会对13X/MgCl2复合吸附剂在室温下的吸附性能有影响,CNT-5在开式、闭式的平衡吸附量可以达到0.52 g·g-1和0.38 g·g-1,分别是13X吸附量(0.24 g·g-1)的2.2和1.6倍,但新型复合吸附剂可以脱附更多的水蒸气。新型复合吸附剂的热导率随着MWCNT含量的增大而升高,CNT-5的热导率可以达到0.265 W·m-1·K-1,是13X热导率的4.9倍。  相似文献   

17.
王磊  李洁  陈耀壮  乔莎  雷菊梅  赵英 《工业催化》2016,24(11):62-67
采用干混法制备了Cu(Ⅰ)-分子筛吸附剂,利用XRD和SEM考察Cu(Ⅰ)在吸附剂表面的分散情况,并对吸附剂吸附条件和解析条件和CO吸附分离性能进行考察。结果表明,Cu Cl呈原子状态分散于分子筛载体孔道内;在吸附温度60℃、吸附压力700 k Pa、解吸温度80℃、解吸压力20 k Pa和解吸时间2 min条件下,吸附剂的穿透吸附量达37.5 m L·g~(-1),解吸量为8.5 m L·g~(-1)。在对CO、CH_4、H_2和N_2混合气进行分离以及增加置换工序的情况下,可将体积分数27%的CO提浓至99.5%,该吸附剂满足工业应用要求。  相似文献   

18.
A nitrogen and sulfur co-doped carbon has been synthesized employing egg white as a sustainable protein-rich precursor. According to CHNS elemental analysis, N, S and O heteroatoms accounted for mass fractions of 3.66%, 2.28% and 19.29% respectively, and the types of surface functionalities were further characterized by FT-IR and XPS measurements. Although the carbon possessed a smaller surface area (815 m2·g-1) compared to a commercial activated carbon (1100 m2·g-1), its adsorption capacity towards Co2+ reached 320.3 mg·g-1, which was over 8 times higher compared to the limited 34.0 mg·g-1 over the activate carbon. Furthermore, the carbon was found to be an efficient adsorbent towards a series of metal ions including VO2+, Cr3+, Ni2+, Cu2+ and Cd2+. Combined with its environmental merits, the protein derived carbon may be a promising candidate for heavy metal pollution control.  相似文献   

19.
High applied thermal-stability and superior structural property for activated carbon adsorbent are extremely promising, which also is the determining short slab in volatile organic compounds (VOCs) adsorption applications. Herein, we develop the outstanding engineering carbon adsorbents from waste shaddock peel which affords greatly-enhanced thermal-stability and super structural property (SLang?=?4962.6?m2·g-1, Vmicro?=?1.67?cm3·g-1). Such character endows the obtained adsorbent with ultrahigh adsorption capture performance of VOCs specific to benzene (16.58?mmol·g-1) and toluene (15.50?mmol·g-1), far beyond traditional zeolite and activated carbon even MOFs materials. The structural expression characters were accurately correlated with excellent adsorption efficiency of VOCs by studying synthetic factor-controlling comparative samples. Ulteriorly, adsorption selectivity prediction at different relative humidity was demonstrated through DIH (difference of the isosteric heats), exceedingly highlighting great superiority (nearly sixfold) in selective adsorption of toluene compared to volatile benzene. Our findings provide the possibility for practical industrial application and fabrication of waste biomass-derived outstanding biochar adsorbent in the environmental treatment of threatening VOCs pollutants.  相似文献   

20.
Malaysian Selantik low-rank coal (SC) was used as a precursor to prepare a form of mesoporous activated carbon (SC-AC) with greater surface area (SA) via a microwave induced KOH-activation method. The characteristics of the SC and SC-AC were evaluated by the iodine number, ash content, bulk density, and moisture content. The structure and surface characterization was carried out using pore structure analysis (BET), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), elemental analysis (CHNS), thermogravimetric analysis (TGA), and determination of the point of zero charge (pHPZC). These results signify a mesoporous structure of SC-AC with an increase of ca. 1160 times (BET SA=1094.3 m2·g-1) as compared with raw SC without activation (BET SA=1.23 m2·g-1). The adsorptive properties of the SC-AC with methylene blue (MB) was carried out at variable adsorbent dose (0.2-1.6 g·L-1), solution pH (2-12), initial MB concentrations (25-400 mg·L-1), and contact time (0-290 min) using batch mode operation. The kinetic profiles follow pseudo-second order kinetics and the equilibrium uptake of MB conforms to the Langmuir model with a maximum monolayer adsorption capacity of 491.7 mg·g-1 at 303 K. Thermodynamic functions revealed a spontaneous endothermic adsorption process. The mechanism of adsorption included mainly electrostatic attractions, hydrogen bonding interaction, and π-π stacking interaction. This work shows that Malaysian Selantik low-rank coal is a promising precursor for the production of low-cost and efficient mesoporous activated carbon with substantive surface area.  相似文献   

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