氨基化MCM-41介孔分子筛改性超滤膜去除水中Cr（VI）的研究

采用氨基化MCM-41介孔分子筛（NH2-MCM-41）接枝改性聚偏氟乙烯（PVDF）超滤膜,并用于水中重金属Cr（VI）的去除。NH2-MCM-41成功接枝于超滤膜表面,并在表面形成均匀的亲水层,显著提高了膜的抗污染性能,过水通量衰减率从51.4%降低到了24.8%。在pH值3.5,初始浓度20 mg/L时,改性超滤膜对Cr（VI）的吸附可以在5 min达到快速平衡,吸附容量达到2.8 mg/g。超滤实验表明,NH2-MCM-41改性超滤膜对低浓度Cr（VI）进水可以实现进一步净化,在超滤运行时长达到11 h,出水Cr（VI）浓度始终维持在0.5 mg/L以下。因此,本研究通过在膜表面接枝氨基化的MCM-41分子筛,可以有效提升膜的抗污染能力和对重金属的去除能力。     

纳米羟基磷灰石对Cu2+的吸附

用溶胶-凝胶法制备纳米羟基磷灰石(n-HAP)吸附水溶液中的铜离子(Cu2+),研究反应时间、体系pH值和Cu2+初始浓度等因素对吸附行为的影响,并探讨吸附机理。结果表明:在溶液pH=4.5~7.5,n-HAP对Cu2+的吸附升高趋势近似线性关系;反应60 min时基本达到吸附平衡;pH>7.5时,溶液中Cu2+几乎完全去除,最大吸附量为51.28 mg/g。n-HAP对Cu2+有良好的吸附作用,吸附类型为Langmu ir等温吸附,吸附过程符合拟二级反应动力学方程。     

新型深海中温菌Wangia profunda(SM A87)胞外多糖对对硝基苯胺的吸附研究

采用深海中温菌Wangia profunda (SM A87)的胞外多糖对对硝基苯胺进行吸附试验。分别用热分析仪、FTIR和Zeta电位仪对胞外多糖进行表征分析,并研究了吸附时间、胞外多糖用量、pH和温度等方面对其吸附规律的影响。结果表明:胞外多糖可有效去除水中的对硝基苯胺。20?℃时,01?g／L的SM A87胞外多糖吸附处理50?mL初始浓度为15?mg／L的对硝基苯胺水样120?min后,对硝基苯胺的最大吸附率可达91％;Langmuir、Freundlich、Redlich Peterson等温方程和准二级动力学方程均能较好地描述SM A87胞外多糖吸附对硝基苯胺的热力学及动力学过程,由Langmuir方程得到SM A87胞外多糖对对硝基苯胺的最大吸附量为7692?mg／g(30?℃)。     

Preparation and electrochemical properties of carbon-coated LiFePO4 hollow nanofibers

Carbon-coated LiFePO₄ hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller specific surface area analysis, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO₄ hollow nanofibers have good long-term cycling performance and good rate capability: at a current density of 0.2C (1.0C = 170 mA·g-1) in the voltage range of 2.5–4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g-1 with a first charge–discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99% after 10 cycles; moreover, the materials can retain a specific capacity of 135.68 mAh·g-1, even at 2C.     

纳米羟基磷灰石对苯酚的吸附

溶胶-凝胶法合成纳米羟基磷灰石(n - HAP)后再吸附水溶液中的苯酚,研究pH值及苯酚的初始浓度和平衡时间对吸附行为的影响,探讨其反应机理.结果表明:在碱性范围内对苯酚的吸附效果好,随着pH值的增加,吸附量逐渐增加,在pH≈11时吸附量能达到23.3mg.g-1;n - HAP对苯酚的吸附属Langmuir等温吸附模型;在120 min时吸附达到平衡,吸附速率符合拟二级动力学方程.     

松树锯末对罗丹明B的吸附

采用松树锯末以及改性锯末为吸附材料,以亚罗丹明B的模拟废水为吸附对象,研究了溶液的pH值、吸附时间、锯末投加量及模拟废水初始浓度对吸附效果的影响.研究表明:在最佳条件下改性前后的锯末对罗丹明B的最大吸附量分别为26.81、39.37 mg/g.同时对改性前后的锯末做了吸附等温线拟合及动力学研究,结果表明吸附等温线均能很好地符合Langmuir或Freundlich吸附模式,吸附过程符合拟二级动力学方程.     

Adsorption of Cd(II) from acidic aqueous solutions by tourmaline as a novel material

Batch experiments were conducted to investigate the behavior and mechanisms for the adsorption of Cd(Ⅱ) from aqueous solutions by tourmaline under acidic conditions. The results indicated that the adsorption of Cd(Ⅱ) significantly depend on the adsorption time, temperature, and the initial concentration of the metal ion. Furthermore, tourmaline had a very good adsorption capacity for Cd(Ⅱ) in acidic, neutral and alkaline aqueous solutions. This good adsorption capacity is attributed to the observation that tourmaline can automatically adjust the pH values of acidic (except pH 2.0 and 3.0), neutral or alkaline aqueous solutions to 6.4. Specifically, the removal capacity for Cd(Ⅱ) was higher at strongly acidic pH values (in contrast to industrial wastewater pH values) compared to that obtained for other types of adsorbents. Furthermore, the results obtained in this study showed good fits to the Langmuir and Freundlich adsorption isotherms. However, the Langmuir model fit better than the Freundlich model. The maximum uptake of Cd(Ⅱ) by tourmaline was 31.77, 33.11 and 40.16 mg/g at pH 4.0 at 15, 25 and 35°C, respectively. Therefore, tourmaline is an effective adsorbent for the removal of Cd(Ⅱ) from acidic aqueous solutions. In addition, the kinetics for the Cd(Ⅱ) adsorption by tourmaline closely followed the pseudo-second-order model. The thermodynamic parameters indicated that adsorption was feasible, spontaneous, and endothermic. Furthermore, the pH variation after adsorption, ζ-potential, metal ions desorbed and released, and FT-IR analysis indicated that the physisorption and chemisorption mechanisms of tourmaline for heavy metals. These mechanisms included water that was automatically polarized by tourmaline, the ion exchange process, and electropolar adsorption. Among the mechanisms, the automatic polarization of water caused by tourmaline is a unique adsorption mechanism for tourmaline.     

Graphene oxide-covered melamine foam utilizing as a hybrid foam toward organic dye removal and recyclability

Graphene-based adsorbents have been attracted extensive interest in recent years. Herein, graphene oxide-covered melamine foam (GO-covered MF) was designed and prepared by a mild submerge-covering method with the support of a super-hydrophilic melamine framework, showing its adsorption performances for various organic dyes. The structure morphology as well as chemical, thermal and mechanical properties of the as-obtained hybrid foam (HF) were further determined for the possible structure changes after covering the GO sheets on the MF framework. Moreover, the HF exhibited an excellent ability for organic dye adsorption application, and which was well fitted in the pseudo-second-order kinetic and Langmuir models corresponding to a chemical adsorption and a mono-layer approach during the adsorption process. The maximum adsorption capacity by using the as-obtained HF corresponded to 258.56 ?mg ?g^?1 (methylene blue), 233.22 ?mg ?g^?1 (Rhodamine B), 206.92 ?mg ?g^?1 (methyl orange), and 184.93 ?mg ?g^?1 (Congo red), which are competitive with that of other graphene-based absorbents. In particular, the HF could be reused without a noticeable degradation of organic dye removal performance. As such, the HF prepared in this study can become an encouraging candidate for practical application owing to the reliable recyclability and low-cost.     

水溶液中的活性翠兰KN-G在一种新型球形木质素吸附剂上吸附特性研究

以马尾松浆厂提供的碱木素为原料研制出一种新型的球形木质素吸附剂SLBA.然后以活性翠兰KN-G为吸附质研究其在这种含有季铵基团的球形木质素吸附剂上的吸附特性.并进行吸附影响因素的优选实验.实验结果表明:活性翠兰KN-G在吸附剂上的吸附效果取决于吸附质溶液的pH值和吸附质的初始浓度.初始浓度的增大有利于提高平衡吸附容量.在3～8的pH范围内,去除率从12.3%迅速升至98.6%,当溶液的pH值为10.0时,去除率达100%.吸附过程符合Langmuir吸附等温式,即(Ce)/(qe)=0.0002136 0.001225Ce.而且,平衡常数的无量纲系数RL为8.711×10-4,远小于0.1,说明活性翠兰KN-G在SLBA上的吸附很容易进行.而且,SLBA吸附剂的饱和吸附容量为816.3 mg/g,总的穿透容量为761 mg/g,吸附效果明显优于活性炭.吸附在SLBA吸附剂上的活性翠兰可用乙醇、双氰胺-甲醛缩聚物和盐酸混合物解析,解析率可达98.7%.     

竹木质纤维素吸附水溶液中铅离子的研究

采用盐酸对竹木质纤维素进行改性,研究其吸附水溶液中铅离子的性能。采用傅立叶红外(FT-IR)对其结构进行了表征。研究了溶液pH、吸附时间、吸附剂用量、溶液浓度等对吸附容量的影响。实验结果表明,4 h后达到吸附平衡,在Pb(II)溶液浓度在100 mg/L时,pH在4.5~5.5范围内时达到最大吸附量,盐酸改性的竹木质纤维素吸附性能较高,表明HCl改性后的竹木质纤维素吸附性能得到提高。利用竹木质纤维素来吸附重金属离子,具有绿色环保,无污染点成本低廉等优点,具有良好的应用前景。     

Organic dye removal and recycling performances of graphene oxide-coated biopolymer sponge

In this study, a biopolymer sponge (PS) with a crosslinked mixture of gelatin-chitosan-poly(vinyl alcohol) was dipped into graphene oxide (GO) solution to form a composite sponge (CS, GO-coated PS) by a combination of simple dip-coating and freeze-drying procedures, as a sponge-like adsorbent in organic dye removal applications. The morphological, chemical, crystalline, mechanical and thermal characterizations of the as-obtained sponges were further investigated for the possible changes in the structure of sponge-like adsorbent after coating the GO sheets on the 3D porous structure of PS. The results showed that the CS had possessed effectively organic dye removal performances comparing to the PS. In the adsorption, the Langmuir and pseudo-second-order models corresponding to a monolayer approach and a chemical adsorption were appropriated. The maximum adsorption capacity of Rhodamine B and Congo red reached 126.8 and 135.0 ?mg?g^?1; and 145.6 and 148.6 ?mg?g^?1 corresponding onto the PS and CS. It indicates that the maximum adsorption capacity on the CS enhanced significantly comparing to those on the PS owing to the functional GO sheets coated in the 3D porous structure of PS, which leads to supplying further functional adsorption sides on the whole 3D porous structure of CS. Notably, the sponges-like adsorbents could be regenerated and used again without a remarkable decrease of dye removal ability occurred in 9 adsorbing–desorbing cycles. Therefore, the CS prepared in this study can become a potential adsorbent for actual applications because of non-toxic materials, proper structural features, low-cost material and operation, and reliable recyclability.     

废啤酒酵母吸附水中苯酚的性能及机理

以啤酒废酵母为材料吸附水溶液中苯酚,考察了溶液pH值、盐浓度、吸附时间对吸附的影响,结果表明:啤酒废酵母吸附苯酚的平衡时间为2 h,在较宽的pH值范围内对苯酚的吸附性能良好,等温曲线符合L angm u ir模式,最大吸附量为108.34 m g/g,高盐浓度对苯酚的吸附有阻碍作用.啤酒废酵母能较好地吸附废水中的苯酚,可望在苯酚废水处理中得到实际应用.     

新型深海中温菌Wangia profunda（SM-A87）胞外多糖对对硝基苯胺的吸附研究

采用深海中温菌Wangia profunda（SM-A87）的胞外多糖对对硝基苯胺进行吸附试验。分别用热分析仪、FTIR和Zeta电位仪对胞外多糖进行表征分析,并研究了吸附时间、胞外多糖用量、pH和温度等方面对其吸附规律的影响。结果表明：胞外多糖可有效去除水中的对硝基苯胺。20℃时,0．1g／L的SM-A87胞外多糖吸附处理50mL初始浓度为15mg／L的对硝基苯胺水样120min后,对硝基苯胺的最大吸附率可达91％;Langmuir、Freundlich、Redlich-Peterson等温方程和准二级动力学方程均能较好地描述SM—A87胞外多糖吸附对硝基苯胺的热力学及动力学过程,由Langmuir方程得到SM—A87胞外多糖对对硝基苯胺的最大吸附量为769．2mg／g（30℃）。     

表面改性活性炭的制备及其去除污水中Cd~(2+)的试验研究

以花生壳生物质炭(PSB)为原料,采用KOH活化法制备了比表面积为461 m2·g-1的花生壳活性炭(K-PSB),利用氮气吸附脱附等温线、SEM等对样品进行了表征,并将孔隙结构发达的花生壳活性炭用于重金属Cd2+的吸附,考察反应时间、溶液p H值、花生壳活性炭的投加量等对Cd2+吸附的影响。结果表明:随着吸附时间的推移,Cd2+的吸附量逐渐增加直至达到平衡,当Cd2+浓度为50 mg·L-1,PH值等于6,投加量为1 g·L-1时,花生壳活性炭对Cd2+的吸附效果最佳;该吸附是一个吸热反应,随着温度的增加,吸附量逐渐增大。     

改性黑木耳对重金属Cr(Ⅵ)的吸附影响因子研究

以盐酸为改性剂,对木耳进行改性制备吸附剂,用改性木耳吸附水溶液中的Cr(Ⅵ),考察了改性盐酸浓度、改性时间、改性温度、溶液pH值、吸附时间、温度等因素对改性木耳吸附Cr(Ⅵ)效果的影响。结果表明,采用5%的盐酸在35℃的条件下改性20 h的木耳对Cr(Ⅵ)的吸附效果较好;当温度为30℃、Cr(Ⅵ)溶液初始浓度为20 mg/L、pH值为2.0时,在改性木耳用量为2.5 g/L、吸附时间为300 min的条件下,Cr(Ⅵ)吸附量可达266 mg/kg;Lagergren一级动力学模型能很好的描述改性木耳吸附水溶液中的Cr(Ⅵ)的吸附动力学过程。     

Application of Nanometer-Size Titanium Dioxide in Extreme-Trace V（Ⅴ） Analysis

0Introduction Vanadiumplaysanimportantroleinmodernindustry,es peciallyinsteelandchemicalindustry.Forinstance,itscompoundsarewidelyappliedintheproceduresofvitrioland petroleumchemicalmanufactureascatalyzers[14].Vanadium hasseveralvalences,butgenerallyitslowvalencesturnintohighoneseasilyinenvironment[5].BecauseV(Ⅴ)isthemost stableandpoisonousone,weoftenlayemphasisonitinenvi ronmentalpollutioncontrol.Vanadiumexistsinenvironmentalwaterwithextremelylowconcentration.Inseawateritscontentislessthan…     

An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr<Superscript>3+</Superscript> removal capacity

A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr(Ⅲ) from aqueous solutions with relatively low initial concentrations of Cr(Ⅲ) (5–100 mg·L-1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr(Ⅲ) removal capacity highly depends on the initial pH value and concentration of Cr(Ⅲ) in the solution. The maximum removal capacity of Cr(Ⅲ) was evaluated to be 85.1 mg·g-1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(Ⅲ) concentration of 5 mg·L-1. This approach enables a higher removal capacity at lower concentrations of Cr(Ⅲ), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(Ⅲ) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(Ⅲ).     

碳纳米管负载离子液体对铜离子吸附研究

采用浸渍法将手性离子液体1-乙基-3-甲基咪唑L-酒石酸盐(EMIML-Tar)负载到羧基化多壁碳纳米管(CNTs)上,对水溶液中Cu~(2+)进行吸附,考察了离子液体加入量、EMIML-Tar/CNTs吸附剂用量、Cu~(2+)初始浓度、pH、吸附温度、吸附时间对吸附性能的影响。结果表明,负载离子液体后能显著提高多壁碳纳米管对Cu~(2+)的吸附能力,当Cu~(2+)初始浓度为20 mg/L,吸附剂用量为25 mg,溶液pH为6.0,吸附温度为298 K,吸附时间为30 min时,EMIML-Tar/CNTs吸附剂对Cu~(2+)去除率达96%,吸附量为19.19 mg/g。应用2种动力学模型对吸附过程进行拟合,结果表明吸附过程可以很好地用准一级动力学方程描述。     

泥炭树脂颗粒吸附活性深蓝K-R研究

以泥炭和聚乙烯醇（PVA）为原料制得泥炭树脂颗粒,用其处理活性深蓝K-R溶液。研究了泥炭树脂颗粒对活性深蓝K-R的吸附条件和吸附动力学关系。结果表明,泥炭树脂颗粒吸附水溶液中活性深蓝K-R的最佳吸附温度为25～30℃,吸附时间为1 h,在较宽的pH范围内有较好的吸附效果,最大吸附量为29.82 mg/g。在最佳吸附条件下,泥炭树脂颗粒对活性深蓝K-R的吸附满足Langmuir和Freundlich等温吸附方程;未达饱和吸附前,吸附过程表现出一级反应动力学的特征。     

Preparation of mesoporous MgO-templated carbons from phenolic resin and their applications for electric double-layer capacitors

Mesoporous carbons were synthesized using thermoplastic phenolic resin (PF) as carbonaceous precursor and magnesium citrate as template precursor. Pore structure was determined as ink-bottle-like geometry through TEM, N2 adsorption analysis combined with TG curves. The porous carbons prepared were then applied as electrode material for electric double-layer capacitors. The capacitor performance was examined in 30 wt% KOH aqueous solution by cyclic voltammetry and galvanostatic charge/discharge measurements. The carbon prepared with MgO/PF mass ratio of 8/2 had a BET surface area of 1920 m² g^?1 and exhibited a capacitance of 220 F g^?1 at a current density of 50 mA g^?1. Besides, the carbon with the ratio of 4/6 had the optimize proportion of mesopores, which ensures its good rate performance that up to 98.3%, expressed as the ratio of the capacitance measured at 1000 mA g^?1 against that at 50 mA g^?1.