氢氧化镁改性硅藻土对阴离子染料的吸附性能研究

对硅藻土进行氢氧化镁改性以提高它对印染废水中染料的吸附性能.采用原位沉淀法由MgCl2及NaOH在硅藻土上制备了氢氧化镁,并用SEM、XRD对改性材料进行了表征;用分光光度法研究了它对阴离子染料的吸附性能.结果显示:改性硅藻土的染料吸附能力比原硅藻土及氢氧化镁都高;染料的吸附等温线采用Langmuir及Freundlich模型拟合,结果表明改性硅藻土对染料的吸附更符合Freundlich模型.     

氧化锰改性硅藻土吸附剂的制备及其染料吸附性能

通过在硅藻土基体上原位生成氧化锰制备一种复合吸附剂材料,采用EDX、SEM及XRD等技术对该吸附剂进行了表征,并对3种染料废水的吸附性能进行研究。结果表明,制备过程中NaOH的前处理可在硅藻体表面形成带负电荷的孔位,有利于氧化锰的复合与分散;复合吸附剂的粒径约11.23μm,其表面的无定形结构氧化锰呈准球形,粒径约为100nm;对染料废水的脱色率结果显示,该复合吸附剂对阳离子和活性染料均具有良好的吸附性能。     

活性炭及硅藻土对染料的吸附特性研究

采用活性炭、硅藻土、氢氧化镁改性硅藻土对1种阳离子染料和2种阴离子染料进行了吸附研究.BET液氮吸附法测定结果显示硅藻土改性后的比表面积增大而平均孔径降低;染料吸附结果表明:硅藻土改性后对天龙红(TR)及雷马素金黄(RGY)两种阴离子染料的吸附性能提高,而对阳离子染料亚甲基蓝的吸附性能降低;改性硅藻土对天龙红的吸附容量大于活性炭,而对雷马寨金黄及亚甲基蓝的吸附容量低于活性炭;采用准一级、准二级两种吸附动力学模型对染料的吸附动力学数据进行了拟合,结果显示改性硅藻土及活性炭的染料吸附过程更符合准二级动力学模型.     

微波合成Zr-AC,Ni-AC和Zn-AC光催化降解印染废水(英文)

采用微波照射法成功制备新型氧化锆、氧化镍和氧化锌负载活性炭纳米颗粒。采用XRD、HR-SEM和BET对合成纳米颗粒进行表征。利用UV-Vis漫反射光谱法研究Zr-AC、Ni-AC和Zn-AC复合材料的光学性能。验证了紫外光照射下印染废水的光催化效率。每隔一定时间观察印染废水的化学需氧量,以计算化学需氧量的去除率。结果表明,Zn-AC复合材料具有明显的光催化性,这归因于紫外光区域吸光度的增大、染料分子的有效吸附能力、辅助电荷转移和电子-空穴对抑制重组。利用Zn-AC复合材料降解印染废水可以得到最大的降解率(82%化学需氧量去除率)。在Zn-AC复合材料表面设计一个可能实现的协同机制。Zn-AC复合材料重复使用5次后,其催化活性无明显降低。     

一种改性HPAM在3.5%NaCl溶液中对Q235钢的缓蚀作用及缓蚀机理

以功能性单体对水解丙烯酰胺(HPAM)进行改性,合成出一系列改性HPAM,测定了其黏均分子量及表观黏度,并对其结构进行了表征;通过腐蚀浸泡试验和电化学试验研究了改性HPAM在3.5%NaCl溶液中对Q235钢的缓蚀作用。结果表明:40℃、黏均分子量为1 300万的改性HPAM具有最佳的缓蚀性能,缓蚀率随着改性HPAM添加量的增加而增大,当添加量为500mg/L时,缓蚀率达到85.16%;改性HPAM是一种以控制阳极为主的混合型缓蚀剂,添加改性HPAM后,电极过程由活化控制转为浓差控制;改性HPAM在Q235钢表面的吸附方式为化学吸附,且符合Langmiur等温吸附模型。     

疏水改性缔合聚合物对含油废水的处理研究与絮凝作用机理

通过絮凝实验考察了自制疏水改性缔合聚合物(Hydrophob ically Mod ified Polym er,简称HPAM)的除油效果,对其絮凝机理进行了探讨,测试了pH值及NaC l浓度对其絮凝效果的影响,由此确定了最佳絮凝条件。研究结果表明,HPAM对于模拟含油废水在pH值为9时,加药量为0.2 mg/L的条件下絮凝效果最佳;HPAM随着盐浓度的升高,黏度增大且絮凝效果提高,表明HPAM以疏水缔合作用为主,具有较好的抗盐性。     

赤泥制备的聚合氯化铝铁处理活性黑KN-B染料废水的研究

利用赤泥制备的絮凝剂聚合氯化铝铁(PAFC)与商品絮凝剂聚合氯化铝(PAC)进行混凝对比实验,以废水中活性黑KN-B染料为处理对象,考察了混凝剂投加量、废水pH值、废水浓度、废水温度、盐基度等因素对絮凝效果的影响。实验结果表明:混凝剂的投加量、废水pH值、盐基度、废水浓度等对混凝效果有明显影响,温度对混凝效果的影响较小。PAC脱色率为90%,PAFC脱色率达到99%。PAFC的处理效果明显优于PAC,而且在实验过程中PAFC的用量少,形成絮体的速度快。     

氮化铝基导热复合材料的制备及性能

以AlN角形粉和AlN球形粉为填料,以PDMS为有机基体,制备不同固含量的导热复合材料,研究了AlN形态、AlN填充分数及粉体表面改性等对导热复合材料粘度及热导率的影响。研究结果表明,与角形AlN粉体相比,球形AlN粉体可显著降低复合材料的粘度,因而有利于获得更高的填充分数和更大的复合热导率。利用KH570对AlN粉体进行表面改性,有利于降低界面热阻,提高复合热导率,改性浓度(质量分数)为2.0%时,复合材料热导率可提高22.5%。     

活性炭-CNT/PEG/硫复合材料的制备与储锂性能研究

通过密封加热熔融的方式制备了添加CNT的活性炭/硫锂离子电池正极活性材料,并对其进行PEG包覆复合改性,制备了C-CNT/S(PEG)正极复合材料。X射线衍射(XRD)图谱显示复合材料具有较强的非晶结构,且单质硫分散在碳材料的微孔之中。扫描电镜(SEM)显示CNT均匀分散在复合材料之中,并形成了三维导电结构。放电比容量测试显示CNT的加入提高了复合材料的放电比容量;PEG包覆的复合改性材料首次放电比容量高达1371.1 m Ah/g,循环50次后放电比容量为662.8 m Ah/g。说明添加CNT及PEG包覆复合改性,使活性炭/硫正极材料的电化学性能显著提高。     

氮化铝基导热复合材料的制备及性能

以AlN角形粉和AlN球形粉为填料,以PDMS为有机基体,制备不同固含量的导热复合材料,研究了AlN形态、AlN填充分数及粉体表面改性等对导热复合材料粘度及热导率的影响。研究结果表明,与角形AlN粉体相比,球形AlN粉体可显著降低复合材料的粘度,因而有利于获得更高的填充分数和更大的复合热导率。利用KH570对AlN粉体进行表面改性,有利于降低界面热阻,提高复合热导率,改性浓度(质量分数)为2.0%时,复合材料热导率可提高22.5%。     

柠檬酸活化赤泥对亚甲基蓝染料废水的吸附净化作用

采用一种活化赤泥吸附剂用于水溶液中亚甲基蓝的吸附净化.考察吸附剂用量、pH值、亚甲基蓝浓度、吸附温度和吸附时间对活化赤泥吸附性能的影响规律.结果表明:采用稀柠檬酸活化处理可显著提高赤泥对染料分子的吸附效率;吸附率随吸附剂用量增加而增加,随初始亚甲基蓝浓度和温度升高而降低;测得活化赤泥对亚甲基蓝的最大吸附容量为30 mg/g,吸附过程符合Langmuir等温吸附模型;吸附动力学过程可用准二级动力学方程描述,计算出吸附过程的表观活化能为9.88 kJ/mol.对吸附过程焓和熵值的计算结果表明,活化赤泥对水溶液中亚甲基蓝染料的吸附是一个自发的放热过程.     

活性炭陶瓷复合材料的苯吸附特性

用硅藻土及木质活性炭为主要原料制备活性炭陶瓷复合材料,通过含炭量、碘吸附值、体积密度、气孔率和抗压强度测试确定最佳制备工艺条件。探讨该活性炭陶瓷复合材料对苯的吸附特性影响,对比分析了活性炭不同添加量、不同烧结温度及不同环境温度对材料苯吸附性能的影响。结果表明适宜的硅藻土与活性炭比值为7∶3,烧成温度为800℃,此时该材料的气孔率达到52.48%,体积密度为1.067 g/cm3,抗压强度为10.466 MPa,碘吸附值为291.24 mg/g,含炭量为25.62%,苯吸附率为9.56%,比表面积为290.72 m2/g。活性炭陶瓷复合材料的苯醛吸附率随着活性炭含量的增加明显加大,但受外界环境温度影响较小。     

3D Oxidized Graphene Frameworks: An Efficient Adsorbent for Methylene Blue

Extraordinary properties of graphene and its derivatives have found application in varied areas such as energy, electronics, optical devices and sensors, to name a few. Large surface area along with specialized functional groups make these materials attractive for removal of dye molecules in solution via adsorption. Industrial effluents contain large amounts of toxic chemicals resulting in pollution of water bodies, which pose environmental hazards in general. Here we report application of 3D oxidized graphene frameworks in the efficient removal of cationic dye molecules such as methylene blue via adsorption. Systematic parametric studies investigating the effect of the initial dye concentration, pH and contact time have been performed. Spectroscopic analysis of the filtrate suggests that tortuous paths in 3D oxidized graphene frameworks result in efficient removal of dye molecules due to enhanced interaction. The hydroxyl groups retained in these 3D oxidized graphene frameworks facilitate adsorption of the dye molecules while passing through the adsorbent. pH studies suggest that maximum removal efficiency for methylene blue was achieved at pH value of 9. The results suggest that these 3D oxidized graphene frameworks can be used for purification of large volumes of contaminated water from cationic dyes in waste water treatment plants.     

载体对二氧化钛光催化降解苯的影响

研究了以活性炭、沸石、膨润土和硅藻土为负载的TiO2对空气中苯的光催化降解性能，并与无负载的TiO2进行了比较，结果表明，选择合适的载体可以起到吸附与催化氧化的协同作用，提高催化效率。     

Results of the study of chemical-, vacuum drying- and plasma-pretreatment of coconut (Cocos nucifera) lumber sawdust for the adsorption of methyl red in water solution

The study to be presented is motivated by the need of certain industries to implement a cost-effective method of cleaning up wastewater from industrial processes, for example the clean-up of dye-tainted wastewater from textile mills. Biomass by-products, for a long time, have been the popular choice for the role of clean-up agents for certain applications but sometimes the efficiency for adsorption of the targeted waste material is not promising and thus the need for pre-treatment of the biomass material. This work will present the results of a study using three methods of pre-treating coconut (Cocos nucifera) lumber sawdust for the adsorption of methyl red dye in water solution, namely; (1) chemical processing using formaldehyde treatment and sulfuric acid treatment, (2) vacuum drying, and (3) plasma treatment. The vacuum drying and plasma treatment utilized a hexapole-magnetized microwave plasma device that uses a 2.45 GHz microwave source. The results showed that there is a dramatic increase in the dye removal efficiency (% dye removal) after the treatment of the coconut sawdust. The highest recorded % dye removal is as follows: formaldehyde treatment (20%), sulfuric acid treatment (40%), vacuum dried (62%), hydrogen plasma (65%), oxygen plasma (67%) and argon plasma (70%). It was also shown that the % dye removal is dependent on the initial dye concentration, adsorbent dosage, contact time, and pH. The adsorption results of this study were fitted with Freundlich and Langmuir isotherm models but the data are better described by the Freundlich isotherm model as compared to Langmuir. From the results of the study, it is concluded that the methods of vacuum drying and plasma pre-treatment are more effective alternative to chemical processing of the coconut lumber sawdust in the adsorption of dye in wastewater.     

氧化石墨烯-壳聚糖复合物的制备及其吸附性能

采用Hummers法合成的氧化石墨烯(GO)与壳聚糖(CTS)制备复合型吸附剂GO-CTS,通过傅立叶红外光谱仪(FTIR)和扫描电镜(SEM)对结构和形貌进行表征。考察pH、投加量、吸附时间以及铀初始浓度等参数对吸附剂去铀效果的影响。结果表明,对于10mg/L的含铀溶液,GO和GO-CTS的最佳吸附条件分别为:pH=4~7,5;投加量1.0,1.0g/L;吸附时间为1,70min;最大去铀率分别为99.5%,97.5%。GO和GO-CTS的吸附平衡符合Freundlich等温线模型,表明为多分子层吸附,主要以物理吸附为主,最大吸附量分别为78.13和114.94mg/g。     

Removal of Quinmerac by Diatomite and Modified Diatomite from Aqueous Solution

Algerian aluminosilicate mineral natural diatomite and its modified variant were applied to remove quinmerac (QM)—a week acid herbicide from aqueous solutions. Then samples were investigated by the transmission electron microscopy, X-ray diffraction analysis, X-ray fluorescence and physical adsorption of gases. The adsorption experiments were carried out at ambient temperature in baths at different pH and the results showed that the amount of adsorbed QM increased at a higher pH, reaching a maximum at pH 2.5. The Langmuir model provided the best correlation of the experimental data for adsorption equilibrium. It was found that the modified diatomite exhibits a slightly better efficiency in the removal of QM than natural diatomite; this is why it could be considered to be an alternative material for removing a specific pollutant from environment.     

Uniform polyaniline microspheres: A novel adsorbent for dye removal from aqueous solution

Uniform polyaniline (PANI) microspheres were synthesized by a facile polymerization of aniline monomer in the acidic medium. The structure and morphology of PANI microspheres were characterized by means of FTIR spectrometer, X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). Adsorption characteristics of PANI microspheres were examined using methyl orange (MO) as adsorbate. Batch adsorption experiments were carried out to investigate adsorption kinetics and isotherms of PANI microspheres. Adsorption equilibrium studies showed that MO adsorption followed Freundlich model. The adsorption kinetics was best described by pseudo-second-order model. The results indicated that PANI microspheres can be used as a novel, effective and low-cost adsorbent material for dye removal.