Synthesis of linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite as an adsorbent for removal of Pb(Ⅱ) from aqueous solutions

The purpose of this work is to remove Pb(II) from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy (FTIR), Solid carbon nuclear magnetic resonance spectroscopy (CNMR)), silicon^-29 nuclear magnetic resonance spectroscopy (Si NMR)), and X-ray diffraction spectroscope ((XRD) were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb(II) from the aqueous solution. The Pb(II)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy (FTIR)), scanning electron microscopy (SEM)), and X-ray photoelectron spectroscopy ((XPS)). From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(II). Kinetic studies indicated that the adsorption of Pb(II) followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb(II) ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent.     

Synthesis of linear low-density polyethylene-g-poly(acrylic acid)-co-starch/organo-montmorillonite hydrogel composite as an adsorbent for removal of Pb(Ⅱ) from aqueous solutions

The purpose of this work is to remove Pb(II) from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy(FTIR), Solid carbon nuclear magnetic resonance spectroscopy(CNMR)), silicon-29 nuclear magnetic resonance spectroscopy(Si NMR)), and X-ray diffraction spectroscope((XRD) were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb(II) from the aqueous solution. The Pb(II)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy(FTIR)),scanning electron microscopy(SEM)), and X-ray photoelectron spectroscopy((XPS)). From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(II). Kinetic studies indicated that the adsorption of Pb(II)followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb(II) ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly(acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent.     

Comparison of activated carbon and iron/cerium modified activated carbon to remove methylene blue from wastewater

The methylene blue(MB)removal abilities of raw activated carbon and iron/cerium modified raw activated carbon(Fe–Ce-AC)by adsorption were researched and compared.The characteristics of Fe–Ce-AC were examined by N_2adsorption,zeta potential measurement,FTIR,Raman,XRD,XPS,SEM and EDS.After modification,the following phenomena occurred:The BET surface area,average pore diameter and total pore volume decreased;the degree of graphitization also decreased.Moreover,the presence of Fe_3O_4led to Fe–Ce-AC having magnetic properties,which makes it easy to separate from dye wastewater in an external magnetic field and subsequently recycle.In addition,the equilibrium isotherms and kinetics of MB adsorption on raw activated carbon and Fe–Ce-AC were systematically examined.The equilibrium adsorption data indicated that the adsorption behavior followed the Langmuir isotherm,and the pseudo-second-order model matched the kinetic data well.Compared with raw activated carbon,the maximum monolayer adsorption capacity of Fe–Ce-AC increased by27.31%.According to the experimental results,Fe–Ce-AC can be used as an effective adsorbent for the removal of MB from dye wastewater.     

羟基磷灰石-四氧化三铁-沸石复合材料制备及去除水中刚果红研究

采用可溶性磷酸盐、钙离子、二价铁离子、三价铁离子和天然沸石等材料制备了羟基磷灰石-四氧化三铁-沸石(HAPFe3O4-沸石)复合材料,对该复合材料进行了表征,并考察了该复合材料对水中刚果红的吸附作用.结果表明,HAP-Fe3O4-沸石复合材料对水中的刚果红具备良好的吸附能力.当pH由3增加到4或由7增加到11时,HAP-Fe3O4-沸石复合材料对水中刚果红的去除能力下降;当pH由4增加到7时,对刚果红的吸附能力基本保持不变.HAP-Fe3O4-沸石复合材料对水中刚果红的去除率随吸附剂投加量的增加而增加,而对水中刚果红的单位吸附量则随吸附剂投加量的增加而降低.HAP-Fe3O4-沸石复合材料对水中刚果红的吸附动力学过程可以较好地采用准二级动力学模型加以描述,对刚果红的吸附平衡数据可以采用Langmuir和Freundlich等温吸附模型加以描述.根据Langmuir模型确定的最大吸附容量为117 mg·g-1.(pH 7和303 K).HAP-Fe3O4-沸石复合材料对水中刚果红的吸附是自发吸热并伴随熵增加的过程.当pH为7时,HAP-Fe3O4-沸石复合材料吸附水中刚果红的主要机制包括表面配位作用、氢键作用以及路易斯酸碱反应.采用热再生的方法可以使吸附刚果红后的HAP-Fe3O4-沸石复合材料得到再生,热再生后的复合材料可以循环使用并且对水中刚果红的吸附性能良好.X射线衍射分析结果表明HAP-Fe3O4-沸石复合材料含Fe3O4,磁滞回线结果表明HAP-Fe3O4-沸石复合材料具备较高的磁饱和强度,复合材料吸附刚果红后可以很容易地通过外加磁场的作用快速地与水溶液分离.结果表明,HAP-Fe3O4-沸石复合材料适合作为一种吸附剂去除废水中的刚果红.     

Functionalized CMK-3 mesoporous carbon with 2-amino-5-mercapto-1,3,4-thiadiazole for Hg(II) removal from aqueous media

Ordered mesoporous carbon（CMK-3） was synthesized and functionalized with 2-amino-5-mercapto-1,3,4-thiadiazole groups（AMT-OCMK-3） for Hg（Ⅱ） removal from aqueous solution. The modified CMK-3 was characterized by X-ray diffraction, N2adsorption-desorption isotherm, scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of solution pH, contact time, initial Hg（Ⅱ） concentration and matrix effect were studied. The adsorption data were successfully fitted with the Langmuir model, exhibiting high adsorption capacity of 450.45 mg/g of AMT-OCMK-3. In the solid-phase extraction system a series of experimental parameters such as sample flow rate, sample volume,eluent volume and concentration of the eluent solution have been investigated and established for preconcentration of Hg（Ⅱ） in aqueous solution. The results showed that the enrichment factor for Hg（Ⅱ） was 250, the precision（relative standard deviation（RSD）, %） for six replicate measurements was 2.05% and the limit of detection for Hg（Ⅱ） was achieved at0.17 μg/L.     

锆-十六烷基三甲基氯化铵改性活性炭对水中硝酸盐和磷酸盐的吸附特性

采用锆(Zr)和阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)对活性炭进行联合改性,考察了所制备的Zr-CTAC改性活性炭对水中硝酸盐和磷酸盐的吸附去除作用,并探讨了相关的吸附去除机制.结果表明,Zr-CTAC改性活性炭对水中硝酸盐和磷酸盐均具备较好的吸附去除能力.Zr-CTAC改性活性炭对硝酸盐和磷酸盐吸附动力学过程满足准二级动力学模型.Langmuir、Freundlich和Dubinin-Radushkevich(D-R)等温吸附模型可以较好地描述Zr-CTAC改性活性炭对水中硝酸盐的等温吸附过程,Langmuir和D-R等温吸附模型可以较好地描述Zr-CTAC改性活性炭对水中磷酸盐等温吸附过程,通过Langmuir模型计算得到吸附剂对硝酸盐和磷酸盐的最大单位吸附量分别为7.58 mg·g-1和10.9 mg·g-1.高的p H会抑制Zr-CTAC改性活性炭对水中硝酸盐和磷酸盐的吸附.水中共存的Cl-、HCO-3和SO2-4等阴离子均会抑制Zr-CTAC改性活性炭对硝酸盐和磷酸盐的吸附,且对吸附硝酸盐的抑制作用较强而对吸附磷酸盐的抑制作用较弱.水中共存的磷酸盐对Zr-CTAC改性活性炭吸附硝酸盐的抑制作用较强,而水中共存的硝酸盐对Zr-CTAC改性活性炭吸附磷酸盐的抑制作用较弱.1 mol·L-1Na Cl溶液可以使90%左右被吸附到Zr-CTAC改性活性炭表面上的硝酸盐解吸下来.1 mol·L-1的Na OH溶液可以使78%左右被吸附到Zr-CTAC改性活性炭表面上的磷酸盐解吸下来.Zr-CTAC改性活性炭对硝酸盐的吸附机制主要包括阴离子交换作用和静电吸引作用,对磷酸盐的吸附机制主要包括配位体交换作用、阴离子交换作用和静电吸引作用.上述结果说明Zr-CTAC改性活性炭适合作为一种吸附剂去除废水中的硝酸盐和磷酸盐.     

TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi₅O₇NO₃) surface was synthesized via a precipitation method using TiO₂ and Ag as modified agents. The synthesized product was characterized by different analytical techniques. The removal efficiency was evaluated using mono-and di-sulphonated azo dyes as model pollutants. Different kinetic, isotherm and diffusion models were chosen to describe the adsorption process. X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi₅O₇NO₃;however, the presence of hydrophilic centres such as TiO₂ and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes. Dyes removal was found to be a function of adsorbent dosage, initial dye concentration, solution pH and temperature. The reduction of Langmuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent. Mass transfer can be described by intra-particle diffusion at a certain stage, but it was not the rate limiting step that controlled the adsorption process. Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.     

Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg(OH)2

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment. Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin (CIP) in aqueous solution. The as-prepared Mg(OH)₂ nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other antibiotics or aromatics, e.g., norfloxacin (NOR) and eosin B (EB). The adsorbent showed pH-dependent adsorption, indicating that the adsorption process is probably dominated by an electrostatic interaction mechanism. In addition, structural analysis of the adsorbent indicated that coordination and hydrogen bonding between CIP and Mg(OH)₂ nanocrystal might also be involved in the adsorption process. Moreover, the adsorbent could be easily recovered by pyrolysis and hydration without significant reduction of adsorption capacity. The superior adsorption behavior of Mg(OH)₂ nanocrystal indicates that it may serve as a potential adsorbent material candidate for the selective removal of CIP from aquatic environments.     

Pb(II) removal from water using Fe-coated bamboo charcoal with the assistance of microwaves

Bamboo charcoal(BC) was used as starting material to prepare iron-modified bamboo charcoal(Fe-MBC) by its impregnation in FeCl 3 and HNO 3 solutions simultaneously,followed by microwave heating.The material can be used as an adsorbent for Pb(Ⅱ) contaminants removal in water.The composites were prepared with Fe molar concentration of 0.5,1.0 and 2.0 mol/L and characterized by means of N 2 adsorption-desorption isotherms,X-ray diffraction spectroscopy(XRD),scanning electron microscopy coupled with energy dispersive X-ray spectrometry(SEM-EDS),Fourier transform infrared(FT-IR) and point of zero charge(pH pzc) measurements.Nitrogen adsorption analyses showed that the BET specific surface area and total pore volume increased with iron impregnation.The adsorbent with Fe molar concentration of 2 mol/L(2Fe-MBC) exhibited the highest surface area and produced the best pore structure.The Pb(Ⅱ) adsorption process of 2Fe-MBC and BC were evaluated in batch experiments and 2Fe-MBC showed an excellent adsorption capability for removal Pb(Ⅱ).The adsorption of Pb(Ⅱ) strongly depended on solution pH,with maximum values at pH 5.0.The ionic strength had a significant effect on the adsorption at pH < 6.0.The adsorption isotherms followed the Langmuir isotherm model well,and the maximum adsorption capacity for Pb(Ⅱ) was 200.38 mg/g for 2Fe-MBC.The adsorption processes were well fitted by a pseudo second-order kinetic model.Thermodynamic parameters showed that the adsorption of Pb(Ⅱ) onto Fe-MBC was feasible,spontaneous,and exothermic under the studied conditions,and the ion exchange mechanism played an significant role.These results have important implications for the design of low-cost and effective adsorbents in the removal of Pb(Ⅱ) from wastewater.     

石墨烯基磁性复合材料吸附水中亚甲基蓝的研究

建立了一种超声辅助共沉淀法制备磁性Fe3O4/氧化石墨烯(Fe3O4/GO)纳米粒子.透射电镜和磁滞回线研究表明,该复合物具有小的颗粒尺寸和超顺磁性.该磁性纳米材料可以吸附废水中的染料亚甲基蓝,实验研究了溶液pH值、吸附剂的用量、时间和温度对亚甲基蓝去除率的影响.结果表明,pH值在6~9范围内,Fe3O4/GO都能高效地吸附亚甲基蓝.反应过程在前25 min反应速率很快,到180 min内达到吸附平衡.该磁性纳米材料对亚甲基蓝的吸附符合Langmuir吸附等温模型和准二级动力学方程,吸附过程是一个自发和吸热过程.该吸附材料对亚甲基蓝吸附容量高,在313 K时Fe3O4/GO的饱和吸附量为196.5 mg·g-1.另外,可以方便地通过外部磁场分离回收吸附剂,利用过氧化氢可以再生重复使用,是一种优良的吸附染料废水的材料.     

核壳式磁性碳纳米吸附剂的制备及其对水环境中金霉素的吸附研究

采用水热法和热处理法制备了高比表面积的核壳式磁性碳纳米吸附剂(Fe3C/Fe@C).该吸附剂具有强磁性内核和石墨碳外壳.考察了Fe3C/Fe@C对水环境中金霉素(CTC)的去除能力.结果表明,Fe3C/Fe@C对CTC表现出极强的吸附性能,其吸附行为符合准二级动力学模型,24 h内吸附达到平衡.CTC的吸附能力随溶液pH(3.5～7.5)的增加而增加,但当pH在7.5～8.5时吸附能力下降.CTC的吸附随溶液温度的增加而降低,随离子强度的增加而增加.溶液中共存腐殖酸浓度为10～50mg.L-1时,CTC的吸附仅降低了10%～20%.在最佳条件下(pH=7.5,T=293 K),由Langmuir吸附模型拟合的CTC最大吸附容量为909 mg.g-1,该吸附容量远大于沉积物和矿物对CTC的吸附.吸附CTC后的Fe3C/Fe@C在磁场作用下可以快速从水样中收集,便于进一步处理,避免对环境的二次污染.这些结果表明,Fe3C/Fe@C可作为水环境中四环素类抗生素去除的一种潜在的高效、绿色吸附剂.     

氨基修饰氧化石墨烯-羧甲基纤维素复合吸附剂的制备及其对Cr (VI)的吸附性能研究

为获得价格低廉、吸附性能优良的石墨烯基吸附剂,以氧化石墨烯（GO）、羧甲基纤维素（CMC）为基材,以聚乙烯亚胺（PEI）为改性试剂,通过化学修饰的方法制备了氨基修饰氧化石墨烯-羧甲基纤维素复合吸附剂（GO-PEI-CMC）.采用扫描电镜（SEM）、傅里叶红外光谱（FT-IR）及X射线光电子能谱（XPS）等表征手段证实了CMC、氧化石墨烯与PEI已成功复合.静态吸附实验表明GO-PEI-CMC对Cr （VI）表现出良好的吸附性能,由Langmuir等温吸附模型所得最大吸附量值为243.92 mg·g^-1.吸附动力学、吸附等温线研究表明GO-PEI-CMC对Cr （VI）的吸附为单分子层、化学吸附过程.GO-PEI-CMC对Cr （VI）吸附性能优良,且具有绿色环保、可生物降解的优点,是一种极具潜力的Cr （VI）吸附剂.     

支化聚乙烯亚胺功能化磁性纳米吸附剂的制备及对Cu2+的吸附研究

为解决水体中重金属Cu²⁺污染,本研究首先采用水热法制备得到超顺磁四氧化三铁纳米粒子,然后使用对Cu²⁺具有强络合作用的含有丰富氨基官能团的支化聚乙烯亚胺接枝到纳米粒子表面,得到Fe₃O₄@BPEI磁性纳米吸附剂。采用红外光谱（FTIR）、X射线粉末衍射（XRD）、透射电子显微镜（TEM）等对其结构、尺寸及形貌进行表征。研究了不同吸附因素对吸附剂吸附Cu²⁺的影响,确定了最佳吸附条件,并通过吸附动力学模型和吸附等温线模型进一步探讨吸附机理。结果表明：支化聚乙烯亚胺成功接枝到四氧化三铁纳米粒子表面。最佳吸附条件为pH=6.0、吸附平衡时间为40 min、吸附剂用量为10 mg。通过实验数据拟合,Fe₃O₄@PEI吸附Cu²⁺的过程符合Langmuir等温吸附方程和拟二级动力学模型,表明吸附过程为化学吸附控制的单分子层覆盖,在303 K时,模型理论饱和吸附量为141.24 mg/g。表明支化聚乙烯亚胺修饰的磁性纳米吸附剂对Cu²⁺具有较强的吸附能力,对水体中Cu²⁺的去除具有一定的应用前景。     

Removal of Cs from water and soil by ammonium-pillared montmorillonite/Fe3O4 composite

To remove cesium ions from water and soil, a novel adsorbent was synthesized by following a one-step co-precipitation method and using non-toxic raw materials. By combining ammonium-pillared montmorillonite (MMT) and magnetic nanoparticles (Fe₃O₄), an MMT/Fe₃O₄ composite was prepared and characterized. The adsorbent exhibited high selectivity of Cs⁺ and could be rapidly separated from the mixed solution under an external magnetic field. Above all, the adsorbent had high removal efficiency in cesium-contaminated samples (water and soil) and also showed good recycling performance, indicating that the MMT/Fe₃O₄ composite could be widely applied to the remediation of cesium-contaminated environments. It was observed that the pH, solid/liquid ratio and initial concentration affected adsorption capacity. In the presence of coexisting ions, the adsorption capacity decreased in the order of Ca^2 + > Mg^2 + > K⁺ > Na⁺, which is consistent with our theoretical prediction. The adsorption behavior of this new adsorbent could be expressed by the pseudo-second-order model and Freundlich isotherm. In addition, the adsorption mechanism of Cs⁺ was NH₄⁺ ion exchange and surface hydroxyl group coordination, with the former being more predominant.     

氧化石墨烯负载零价纳米铁吸附水中环丙沙星的研究

通过溶液还原法制备了氧化石墨烯负载零价纳米铁NZVI16-GO1(F16G1),并将其用于水中环丙沙星的去除.同时,采用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)、能谱仪(EDS)和热重分析仪(TG)等手段表征了F16G1的结构、化学组成和微观形貌.结果发现,F16G1对水中环丙沙星具有良好的吸附性能;氧化石墨烯的引入可以有效降低零价纳米铁的自身团聚;F16G1与环丙沙星的吸附作用很大程度上受静电引力的影响.实验同时考察了p H值、反应时间、初始浓度、投加量等因素对F16G1吸附环丙沙星的影响.结果表明,在p H=4~5之间,溶液的p H值对吸附量没有明显影响;F16G1对环丙沙星的最大吸附量是656.66 mg·g-1;Langmuir等温吸附模型可以用来描述吸附平衡过程.零价纳米铁的磁性使复合材料便于回收.     

Removal of tetracycline from aqueous solution by a Fe3O4 incorporated PAN electrospun nanofiber mat

Pollution of antibiotics, a type of emerging contaminant, has become an issue of concern, due to their overuse in human and veterinary application, persistence in environment and great potential risk to human and animal health even at trace level. In this work, a novel adsorbent, Fe₃O₄ incorporated polyacrylonitrile nanofiber mat (Fe-NFM), was successfully fabricated via electrospinning and solvothermal method, targeting to remove tetracycline (TC), a typical class of antibiotics, from aqueous solution. Field emission scanning electron microscopy and X-ray diffraction spectroscopy were used to characterize the surface morphology and crystal structure of the Fe-NFM, and demonstrated that Fe-NFM was composed of continuous, randomly distributed uniform nanofibers with surface coating of Fe₃O₄ nanoparticles. A series of adsorption experiments were carried out to evaluate the removal efficiency of TC by the Fe-NFM. The pseudo-second-order kinetics model fitted better with the experimental data. The highest adsorption capacity was observed at initial solution pH 4 while relative high adsorption performance was obtained from initial solution pH 4 to 10. The adsorption of TC on Fe-NFM was a combination effect of both electrostatic interaction and complexation between TC and Fe-NFM. Freundlich isotherm model could better describe the adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was 315.31 mg/g. Compared to conventional nanoparticle adsorbents which have difficulties in downstream separation, the novel nanofiber mat can be simply installed as a modular compartment and easily separated from the aqueous medium, promising its huge potential in drinking and wastewater treatment for micro-pollutant removal.     

Amino-functionalized core-shell magnetic mesoporous composite microspheres for Pb(II) and Cd(II) removal

Amino-functionalized Fe3O4@mesoporous SiO/ core-shell composite microspheres NH2-MS in created in multiple synthesis steps have been investigated for Pb（Ⅱ） and Cd（Ⅱ） adsorption. The microspheres were characterized by transmission electron microscope （TEM）, scanning electron microscope （SEM）, N2 adsorption-desorption, zeta potential measurements and vibrating sample magnetometer. Batch adsorption tests indicated that NH2-MS exhibited higher adsorption affinity toward Pb（Ⅱ） and Cd（Ⅱ） than MS did. The Langmuir model could fit the adsorption isotherm very well with maximum adsorption capacity of 128.21 and 51.81 mg/g for Pb（Ⅱ） and Cd（Ⅱ）, respectively, implying that adsorption processes involved monolayer adsorption. Pb（Ⅱ） and Cd（Ⅱ） adsorption could be well described by the pseudo second-order kinetics model, and was found to be strongly dependent on pH and humic acid. The Pb（Ⅱ）- and Cd（Ⅱ）-loaded microspheres were effectively desorbed using 0.01 mol/L HC1 or EDTA solution. NH2-MS have promise for use as adsorbents in the removal of Pb（Ⅱ） and Cd（Ⅱ） in wastewater treatment processes.     

金属有机骨架MIL-68(Al)对水中典型荧光增白剂VBL的吸附去除

以金属有机骨架材料MIL-68(Al)为吸附剂,探究其对水中典型荧光增白剂VBL分子的吸附行为.采用粉末X射线衍射仪(XRD)、傅里叶变换红外光谱(FTIR)、场发射扫描电镜(SEM)及N_2吸附脱附对MIL-68(Al)的结构性质进行表征.探讨了p H值、离子强度、污染物初始浓度、反应温度及吸附时间对MIL-68(Al)吸附去除水中VBL的影响,并对吸附等温线、动力学、热力学及吸附机制进行了分析.实验结果表明,MIL-68(Al)对VBL的吸附能适应较宽的p H范围,吸附等温线符合Langmuir模型,最大吸附容量达到400.02 mg·g~(-1);吸附速率在前20 min很快,并且能在180 min达到吸附平衡,吸附动力学符合准二级动力学模型;吸附过程是吸热反应,吸附自发进行并且主要由熵驱动;静电作用和氢键作用对吸附均有贡献,静电作用是吸附发生的主要机制.由以上结果可知,MIL-68(Al)是一种潜在的高效吸附剂,在去除水中的VBL分子方面极具潜力.     

镁盐改性生物质炭的合成及其在废水氮磷资源化中的应用研究

通过直接沉淀-热改性法将纳米氢氧化镁晶体(Mg(OH)_2)负载在生物质炭(BC)上,系统研究了该改性材料(Mg(OH)_2-BC)对模拟废水中氮、磷的固定特性,并探讨了投加量、反应溶液pH、接触时间对吸附过程的影响.结果表明,Mg(OH)_2-BC在投加量为0.3 g·L~(-1),反应溶液初始pH为7,反应时间≥40 min时对氮、磷的固定效果最佳,最大吸附量分别达到58.8、130.0 mg·g~(-1).Mg(OH)_2-BC对氮、磷的吸附过程均符合准二级动力学模型,吸附过程受化学吸附机理的控制.通过SEM、XRD、FTIR等对反应产物进行表征分析,结果表明,Mg(OH)_2-BC对氮、磷的固定机制主要为鸟粪石结晶沉淀,也即化学沉淀.     

碘氧化铋/钨酸铜复合材料的制备及对氟喹诺酮类抗生素的吸附性能

为开发高效抗生素吸附剂,将钨酸铜通过静电作用负载到碘氧化铋晶体表面,制备了新型多金属氧酸盐复合材料（BiOI/CuWO₄）,并以扫描电镜、傅里叶红外光谱与X射线能谱等对其进行表征.选用环丙沙星（CIP）、恩诺沙星（ENR）、诺氟沙星（NOR）、氧氟沙星（OFL）这4种典型氟喹诺酮类抗生素（FQs）作为研究对象,在建立同时测定这4种FQs的高效液相色谱分析方法基础上,研究了BiOI/CuWO₄对FQS的吸附性能及溶液pH值和吸附剂量等对吸附的影响.结果表明,实验浓度范围内BiOI/CuWO₄对NOR、CIP、ENR和OFL的最大吸附量分别为277.8、149.3、113.6和112.4 mg·g^-1,且能够在3 h内达到吸附平衡,吸附动力学符合准二级吸附动力学模型,对CIP、ENR和OFL的吸附等温线基本复合Langmuir模型,而对NOR的吸附则更加符合Freundlich模型.与其它吸附剂相比,BiOI/CuWO₄对4种典型FQs具有较高的吸附量及较好的重复利用性,更符合实际应用需求.