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磁性沸石的制备与表征及其对Pb2+的吸附性能 总被引:1,自引:0,他引:1
通过氨基甲酸乙酯的粘结作用使天然沸石与Fe3O4结合,制备了具有吸附和磁性能的沸石复合体. 利用XRD, SEM, 氮吸附等温线和振动样品磁强计等对所制磁性沸石进行了表征. 结果表明,与钠型沸石相比,磁性沸石的结构没有发生明显改变,比表面积由25.13 m2/g增至38.01 m2/g. 磁性沸石和钠型沸石对模拟废水中Pb2+的平衡吸附量分别为54.53和66.99 mg/g,两者对Pb2+的吸附符合Langmuir型液相吸附,其单层饱和吸附量分别为50.89和65.92 mg/g. 相似文献
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煤燃烧是全球最主要的人为汞排放源,燃煤电厂含汞脱硫废水大量排放对人类健康和生态环境造成严重威胁,亟需开发高效、经济的脱硫废水汞离子脱除技术。对燃煤副产物飞灰进行活化后提取铝硅矿物,并利用飞灰中的铁质矿物制备了磁性沸石汞吸附剂,解决吸附剂吸附汞后难以从废水中分离,造成汞二次释放问题。采用BET、XRD、TEM等表征手段对合成的磁性沸石进行表征分析,系统研究了固液比、溶液初始pH、振荡时间等参数对磁性沸石汞离子吸附性能的影响,对磁性沸石吸附汞离子过程进行动力学研究,结果表明合成的磁性沸石为球形核壳结构,磁核被沸石均匀包裹,磁性沸石的比表面积为4.46 m2/g,最可几孔径为18.25 nm,属于介孔范围,磁性沸石表现出磁化滞后,其矫顽力约10 000 A/m,可通过外加磁场从脱硫废水中分离。试验最佳吸附条件为固液比5 g/L、最佳初始pH为5、振荡时间90 min,在此条件下Hg2+脱除率达92%。动力学研究结果表明,准一级动力学模型能较准确描述Hg2+吸附量随时间的变化,拟合的平衡吸附容量为23.24 mg/g,优于商业活... 相似文献
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以红土和人造沸石为原料,戊二醛为交联剂,成功制备出磁性沸石RAG。X射线衍射光谱(XRD)和傅立叶变换红外光谱(FTIR)表征结果表明,合成的RAG保持了红土和人造沸石的结构和特性。将该磁性吸附剂应用于对水溶液中镍的吸附,研究了pH、温度、时间、镍溶液含量、吸附剂投加量对吸附性能的影响,结果表明,RAG对水溶液中镍的吸附量随p H的升高而增大,吸附过程满足拟2级动力学模型和Freundlich等温吸附模型,3 h时达到吸附平衡,303 K时最大吸附量为23.27 mg/g,吸附剂投加量为8.0 g/L时镍的平衡质量浓度低于1.0 mg/L,满足GB 8978-1996排放标准。 相似文献
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磁性天然沸石的制备及其对Pb2+和Cu2+的吸附性能 总被引:2,自引:1,他引:1
采用化学共沉淀法将具有吸附特性的天然沸石与磁性氧化铁颗粒结合,制备了具有吸附特性的磁性沸石复合体. 利用XRD、氮吸附等温线、FT-IR光谱、SEM和振动样品磁强计等手段对制备的磁性沸石进行了表征. 结果表明,与钠型沸石相比,磁性沸石的结构没有发生明显变化而比表面积由25.13 m2/g增大到100.90 m2/g. 对模拟废水中Pb2+和Cu2+的吸附研究可知,磁性沸石对Pb2+和Cu2+的吸附依赖于pH值的变化,且在pH>4.5时去除效率均大于90%;同时,在不同初始浓度的废水溶液中,磁性沸石对Pb2+和Cu2+的最大吸附量分别为19.44和6.20 mg/g. 相似文献
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以粉煤灰为原料,在温和条件下水热合成粉煤灰基沸石分子筛,并通过正交试验研究了碱浓度、晶化时间、晶化温度对粉煤灰吸附重金属Cu2+性能的影响,确定在晶化时间10 h、晶化温度80℃、NaOH的质量浓度为8%的工艺条件下合成的分子筛对Cu2+吸附效果最好.经X射线衍射仪分析表明,合成的产物含有NaP1型微孔沸石分子筛.通过比表面积分析仪分析测定样品的比表面积为45.98 m2/g.用优化工艺合成的分子筛去除含铜废水,1500 mg/L的沸石处理该废水30 min,去除率达到93.9%,结果表明,合成的分子筛具有良好的吸附性能.因此,本实验合成工艺简单,条件温和,降低了能源成本和最小化环境影响,有利于工业大规模生产. 相似文献
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采用共沉淀法一步合成系列类水滑石负载磁性粒子的颗粒,经煅烧得到磁性焙烧产物.利用焙烧产物吸附水中腐殖酸,得到磁性焙烧态锌铝类水滑石去除腐殖酸效果较好.考察了磁性焙烧态锌铝类水滑石制备条件对腐殖酸去除效果的影响,通过正交试验优化了制备条件.静态吸附实验表明:吸附剂投加量0.2 g/L, 30 min内20 mg/L腐殖酸去除率为97.96%.X射线衍射(XRD)、红外光谱(FT-IR)、热重-差热(TG-DSC)和比表面积(SSA)表征结果表明:一定量的磁性基质掺入并没有破坏锌铝类水滑石典型的层状结构;焙烧态产物为氧化物,磁性保持良好;比表面积达80.00 m2/g.磁性焙烧态锌铝类水滑石在水中因"记忆效应"而结构重建通过表面吸附和腐殖酸结构中小尺寸的官能团插层快速去除腐殖酸. 相似文献
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粉煤灰合成沸石去除废水中铜离子的研究 总被引:1,自引:0,他引:1
粉煤灰通过碱熔融预处理,采用水热法(HT)和微波辅助水热法(MW)均合成了单一的NaPl型沸石,研究了溶液pH值和吸附时间对两种沸石产品去除废水中铜离子效果的影响,探讨了沸石产品去除铜离子的吸附机理.研究表明,合成的两种沸石产品对铜离子具有较强的脱除能力,pH值为6,沸石用量10 g/L,吸附30 min时,铜离子去除率均可达95%以上.铜离子的吸附过程符合Langmiur吸附等温方程式,两种沸石产品的静态饱和吸附量分别为70.08 mg/g和53.30 mg/g. 相似文献
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分别采用回流法和水热合成法制备了铁酸钴(CoFe2O4)磁流体和4A沸石,再将二者制成CoFe2O4载量不同的磁性4A沸石,利用离子交换法制备了Ag+载量不同的磁性银型4A沸石,对其形貌、粒度、磁性能、抗菌性能及用于含菌废水处理后的磁分离回收性能进行了研究。结果表明,CoFe2O4的晶粒尺寸为12.7 nm,性能稳定,具良好的超顺磁性;4 A沸石多为完整的立方体晶形,纳米级CoFe2O4附着在4A沸石表面,磁性4A沸石具有超顺磁性,当铁酸钴的载量为25%时,磁性4A沸石的饱和磁化强度Ms为17.842 A.m2/kg、剩余磁化强度Mr为4.8257 A.m2/kg、矫顽力Hci为427.73 G;磁性银型4A沸石对大肠杆菌和金黄色葡萄球菌的抗菌效果良好,均随Ag+载量的增加而提高,Ag+载量为271.71 mg/g的磁性4A沸石对大肠杆菌的抗菌率和再生抗菌率分别为99.71%和99.67%;磁性银型4A沸石用于含菌废水处理后,利用磁分离技术极易将悬浮液中的抗菌剂进行回收,当CoFe2O4载量为25%时,其磁分离回收率达到96.36%。 相似文献
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以硅酸钠和偏铝酸钠为原料,通过水热合成法制备钴掺杂NaP分子筛,通过X射线衍射光谱(XRD)、扫描电子显微镜(SEM)、N2吸附-脱附等表征手段对样品的晶相、形貌和孔结构进行表征分析,并对其Pb(II)吸附性能进行评价。结果表明:与未掺杂钴的NaP分子筛相比,掺杂量为n(Al2O3)∶n(Co(NO3)2)=8∶1的Co-NaP分子筛的比表面积增大了约5倍(从26.767 m2/g增大到162.490 m2/g);其孔容约增大了约2.5倍(从0.029 cm3/g增大到0.104 cm3/g)。吸附时间为120 min,吸附温度为25 ℃,Pb(II)初始浓度为100 mg/L时,Co-NaP分子筛对Pb(II)的去除率可达98.8%,以乙二胺四乙酸二钠为再生助剂,在30 ℃下再生30 min,可使吸附后时Co-NaP分子筛完全再生,再生后的吸附剂经过3次吸附-再生循环后,Pb(II)去除率仍可达97%。 相似文献
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磁性水热炭兼具水热炭的吸附性能和磁性材料可回收的优点,是一种具有广阔应用前景的水处理吸附材料。目前,磁性水热炭一般采用两步法制备,工艺较为复杂。为此,本文以马尾松锯末为原料,以FeSO4作为磁化剂,NaOH作为活化剂,1,2-丙二醇作为还原剂,开发一步法制备磁性水热炭技术。考察了反应温度、反应时间对磁性水热炭产率和结构的影响,采用XRD、SEM、BET、VSM等对产品进行表征,并将磁性水热炭用于去除水中Cu2+离子。结果表明:随着反应温度的升高和反应时间的增加,磁性水热炭的产率逐渐降低,但比表面积增加,磁性增强。在水热反应温度为240℃、反应时间为8h的条件下,制备的马尾松基磁性水热炭具有良好的吸附性能和磁性,磁性水热炭对Cu2+吸附量为9.58mg/g,最大饱和磁化强度3.74emu/g,具有较好的应用潜力。 相似文献
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Wei‐Sheng Guan Jun‐Ru Lei Xu Wang Ya Zhou Chen‐Chen Lu Shao‐Fang Sun 《应用聚合物科学杂志》2013,129(4):1952-1958
Magnetic nanoparticles were attached to yeast by co‐precipitation reaction of FeCl3·6H2O and FeCl2·4H2O. Then, based on magnetite yeast composites (M@Y), the magnetic molecularly imprinted polymers (MMIPs) were synthesized for the selective recognition of beta‐cypermethrin (PP321). MMIPs were characterized by scanning electron microscopy, X‐ray diffraction, vibrating sample magnetometer, Fourier transform infrared analysis, thermogravimetric analysis, and elemental analysis. MMIPs exhibited uniform morphology and magnetic property (Ms = 17.87 emu/g) and thermal stability. Batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics, and selective recognition. The Langmuir isotherm model was fitted to the equilibrium data slightly better than the Freundlich model, and the adsorption capacity of MMIPs was 39.64 mg/g at 298 K. The kinetic properties of MMIPs were well described by the pseudo‐second‐order equation. Hydrogen bonds between methacrylic acid and PP321 were mainly responsible for the adsorption mechanism. The MMIPs prepared were applied to the separation of PP321 from experimental samples successfully. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Huan Zhang Lin Chen Longfei Li Yongzhen Yang Xuguang Liu 《Journal of Porous Materials》2017,24(2):341-353
Magnetic porous carbon microspheres (MPCMs) based on Fe3O4-encapsulating carbon composites for removing methylene blue (MB) in aqueous solutions were synthesized by simultaneous activation and magnetization. A series of MPCMs were prepared by combining hydrothermal and annealing treatment with α-Fe2O3 nanoparticles as iron source, glucose as carbon source and ZnCl2 as porogen. The phase structure, specific surface area, porosity, thermostability, magnetic property, as well as morphology of as-prepared MPCMs were verified by X-ray diffraction, Brunauer–Emmeltt–Teller surface area analysis, thermogravimetric analysis, vibrating sample magnetometry, field emission scanning electron microscopy and high resolution transmission electron microscopy. The results indicate that the maximum specific surface area of MPCMs is up to 480.32 m2/g when the mass ratio of ZnCl2/glucose is 0.25, which is designated as MPCMs-0.25. The saturation magnetism of MPCMs-0.25 is 30.16 emu/g. Adsorption properties of MPCMs were detected by using MPCMs-0.25 as adsorbent to remove MB from aqueous solution. The outcomes suggest that the adsorption reaches equilibrium within 35 min and physical adsorption is involved in the whole adsorption processes. The results of adsorption isotherm reveal that the adsorption process might include monolayer and porous adsorption, meanwhile, various adsorption sites exist on the surfaces of MPCMs-0.25. The reusability and stability of MPCMs-0.25 were also confirmed by five adsorption–desorption cycle experiments. 相似文献
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NaOH改性沸石吸附地下水中铁锰效能研究 总被引:4,自引:0,他引:4
为了提高沸石对铁锰的吸附性能,利用3种不同改性剂对天然沸石进行改性比较对铁锰的去除效果。通过NaOH改性沸石除铁锰的静态吸附试验研究,考察改性沸石对铁锰的去除效果。结果表明NaOH改性沸石对铁锰的去除效果优于NaCl和HDTMA改性沸石对铁锰的去除效果,NaOH改性沸石的投加量、改性沸石的对铁锰的吸附时间、原水的pH值等因素对铁锰的去除效果有较大的影响,最佳投加量为50g/L,最佳吸附时间为120min,最佳pH值为中性偏酸性或者偏碱性且pH值〈8时,对铁锰的吸附规律较好的符合Langmuir吸附等温式。NaOH改性沸石对铁去除率可达83.09%,对锰的去除率为49.65%。经过改性,沸石对铁锰的去除率和吸附容量都有了较大的提高。 相似文献
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Brian E. Spiewak Brent E. Handy Sanjay B. Sharma J. A. Dumesic 《Catalysis Letters》1994,23(3-4):207-213
The acidities of-Al2O3, HNa-Y zeolite, and H-mordenite have been examined by microcalorimetric measurements of ammonia adsorption at 423 K. The differential heat of adsorption on -Al2O3 decreases continuously with ammonia coverage from an initial value of 165 kJ/ mol at low coverages to a value of 70 kJ/mol at higher coverages. The differential heat of adsorption on HNa-Y zeolite shows similar behavior, with a plateau of nearly constant heat at 115 kJ/mol. H-mordenite exhibits a nearly constant heat of adsorption equal to 155 kJ/mol. The results from these microcalorimetric measurements are in agreement with thermogravimetric and temperature-programmed desorption results collected at higher temperatures. Adsorbed ammonia has sufficient mobility at 423 K to equilibrate with the catalyst surface on the time scale of microcalorimetric measurements, and these measurements provide an effective method for quantifying acid site distributions of solid-acid catalysts. 相似文献