Loading of Fe/Al compounds and adsorption of vanadium (V) on diatomite from Changbai Mountain

Abstract

In this study, the loaded diatomite was prepared with Changbai Mountain diatomite as the carrier according to different Fe/Al molar ratios. The structure and adsorption of the above materials were characterized by XRD, SEM, and ICP-OES. The effects of Fe/Al molar ratio, adsorption time, initial concentration of V(V), and the initial pH value of the solution on the adsorption performance of loaded diatomite were explored. The diatomite loaded with Fe/Al compounds could significantly improve the removal efficiency of V(V), and the removal efficiency of loaded diatomite prepared according to a Fe/Al molar ratio of 1:3 was better. Reaction equilibrium time is 24?h and the pseudo second-order kinetic equation can better describe the adsorption kinetic behavior of V(V) on loaded diatomite. When the initial concentration of V(V) increased from 15.85?mg/L to 122.5?mg/L, the unit adsorption capacity and removal rate of V(V) by loaded diatomite increased continuously. The adsorption behavior of V(V) on loaded diatomaceous earth belongs to the chemical adsorption via the multi-molecular layer, which is consistent with the Freundlich isotherm adsorption model. A weak acid environment is beneficial to the adsorption behavior of V(V) on loaded diatomaceous earth and the strong alkaline environment should be avoided.     

The membrane properties of alumina-coated alumina support layers and alumina-coated diatomite–kaolin composite support layers

ABSTRACT

Porous ceramic membranes are a current research focus because of their outstanding thermal and chemical stability. Recent research has utilised inexpensive natural materials such as diatomite to reduce the expense of these porous ceramic membranes. However, insufficient data exist for microfiltration applications using the diatomite-based membranes. The measured membrane properties of alumina-coated alumina support layers and alumina-coated diatomite–kaolin composite support layers have been compared. These experiments have been used to determine whether the average pore size could be reduced effectively by controlling the thickness of the alumina coating layer, while maintaining acceptable water permeability. The membrane properties of the alumina-coated alumina support layers and the alumina-coated diatomite–kaolin composite support layers were examined using the scanning electron microscopy, mercury porosimetry, and a dead-end microfiltration system.     

食品级硅藻土脱除湿法磷酸中氟的实验研究

为降低湿法磷酸脱氟成本,以食品级硅藻土替代白炭黑作为脱氟剂对湿法磷酸进行脱氟。研究食品级硅藻土的脱氟效果,分析脱氟成本,并与白炭黑作脱氟剂进行比较。结果表明,利用食品级硅藻土作为脱氟剂,脱氟率为75.64%~82.05%,优于白炭黑的67.94%~76.92%,脱氟成本较白炭黑降低3.72~8.20元/t,除氟后磷酸满足饲料级磷酸盐生产的要求。     

硅藻精土技术在中小城镇污水处理中的应用

介绍了硅藻精土水处理技术的除污机理及其在国内的应用情况,根据目前已施工项目的实际运行情况,指出了硅藻精土技术应与其他生化技术进行组合,并作为深度处理单元置于生化单元之后。重点介绍了A／O与硅藻精土组合工艺的特点、流程及设计参数,通过与CAST、氧化沟工艺的技术特点及经济指标的比较,说明了该工艺具有投资省、运行费用低、占地少、出水水质优等特点,适于中小城镇的污水处理。     

光催化混凝土物理力学性能研究

光催化混凝土是将光催化技术应用于混凝土中,通过光照等自然条件发生光催化反应,开发出环境友好的混凝土材料,改善空气质量和生活环境。选取不同掺量的纳米TiO2,设计平行试验制备光催化混凝土并对其各方面性能进行测试分析。结果表明,随着纳米TiO2掺量的增加,光催化混凝土的吸水率下降,软化系数提高,7、28 d抗压强度以及不同时段的光催化性能都先升高后降低;一定量硅藻土的掺入对于光催化混凝土的物理力学性能具有积极的影响。     

硅藻土多孔陶瓷的耐蚀性及酸/碱处理研究

采用注浆成型的方法制备硅藻土多孔陶瓷，对不同温度烧结样品的耐酸、碱腐蚀性进行了研究。材料的耐酸蚀性优于耐碱蚀性。硅藻土多孔陶瓷经过酸或碱处理后，微观结构和宏观性能会发生相应变化，也可利用这一特性通过酸或碱处理来控制瓷的微结构和过滤性能，碱处理样品、酸处理样和原始样品的氮气通量分别为1189、802和677m^3m^-2h^-1bar^-1。     

硅藻土脱色机理及其在印染废水中应用的研究

采用染料吸附法研究了次甲基兰在浙江和吉林硅藻土表面的吸附等温线。还研究了浙江土对印染水的处理及ＰＨ对其影响,并筛选出用为渣和硅藻土处理印染废水,效果良好。     

硅藻土改性黏胶纤维家纺面料的设计开发

以本白色硅藻土改性黏胶纤维和淡黄色原色竹浆纤维为原料设计开发一款特色家纺面料。纺纱工艺为精梳紧密纺,交织比例为80/40;面料颜色为黄白相间,采用本色原纱交织,不经过纱线和面料染色工序;花型分为大提花和小提花两类。不同花型与黄白色彩搭配设计的整体效果高雅精致、环保、舒适。经测试,面料成品符合婴幼儿及儿童纺织产品安全技术规范A类标准。     

金属型离心铸铁管硅藻土水基涂料的研制

介绍了金属型离心铸铁管硅藻土水基涂料中材料的选用及作用,并通过正交试验方法最终确定了符合生产要求的硅藻土水基涂料配方。     

Isothermal crystallization behavior of polyoxymethylene with and without nucleating agents

Nucleation effects of two silicate nucleating agents, attapulgite and diatomite, on the crystallization of polyoxymethylene (POM), were studied by means of differential scanning calorimetry and polarized optical microscopy. The crystallization kinetics of POM with and without nucleating agents was analyzed by means of two isothermal crystallization kinetic equations through the crystallization thermograms. Compared with virgin POM, POM with nucleating agents of attapulgite and diatomite decreased the spherulitic size of POM and interfacial free energies per unit area perpendicular σ_e. The crystallization growth rate was accelerated because of nucleating agents as well. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 304–310, 2001