改性活性氧化铝除氟性能研究

通过静态实验,研究了改性活性氧化铝(MAA)对F-的吸附性能,考察了吸附时间、改性活性氧化铝的用量对除氟性能的影响,并与新型除氟树脂的除氟性能进行了比较.研究结果表明:活性氧化铝的用量为4 g时,除氟效率最高,为94.57%;活性氧化铝与含氟水的最佳接触时间为3 h;MAA在较低用量(＜4 g)时,除氟效率不如除氟树脂高,但是在较高用量(≥4 g)下,MAA则高于树脂的除氟效率.     

硫酸与氯化铝复合改性活性氧化铝吸附除氟研究

采用硫酸与氯化铝复合方法对活性氧化铝进行了改性,研究了改性活性氧化铝吸附动力学特征及主要影响因素,并测定了改性前后活性氧化铝的比表面积、孔容孔径和元素含量等,初步探讨了改性除氟的机理。结果表明,改性吸附剂对水中氟的吸附动力学符合拟2级吸附速率方程,其吸附行为更符合Langmuir等温线的拟合,即吸附为单分子层吸附,其最大吸附容量为6.46 mg/g,是未改性活性氧化铝的4.4倍;改性活性氧化铝的适宜pH为6~7,竞争离子由弱到强的的影响顺序为NO3-≈Cl-SO42-H2PO4-HCO3-HPO42-CO32-;BET和XRF分析表明,改性活性氧化铝除氟主要靠离子交换作用。     

活性氧化铝对水中F-的吸附特性及其影响因素

以活性氧化铝作为吸附剂,研究其对水中F-的去除性能,同时探究了吸附剂的投加量、温度、p H对吸附效果的影响。结果表明:活性氧化铝对水中的F-有较好的去除效果,符合准一级吸附动力学方程。用Langmuir方程拟合的最大吸附量为4.39mg/g (25℃)。反应的吉布斯自由能(ΔG)为-20.77～-22.05kJ/mol,说明吸附是一个自发的过程。活性氧化铝对水中F-的吸附量随pH的升高而降低,最佳应用pH为5～7;最佳投加量为2.0g/L;当外界温度从15℃增加到35℃时,吸附量增加了0.1～1.1倍,因此,活性氧化铝应用于北方高氟地下饮用水处理时,冬季应考虑附加增温、保温设施。     

超声波振荡对活性氧化铝除氟性能的影响

在超声波振荡搅拌下,实验研究了活性氧化铝对氟离子的吸附性能,分析了活性氧化铝颗粒大小、超声波振荡时间、pH、活性氧化铝加入量及原水氟浓度对吸附性能的影响。研究结果表明：活性氧化铝结晶不完整及晶格的无序使得它具有更大的比表面积;使用超声波振荡时,其除氟速率比机械搅拌快得多,除氟前期其平均除氟速率达0.93 mg/min,是机械搅拌除氟速率的5.8倍。同时,采用超声波振荡达到平衡的时间是机械搅拌的1/7,其饱和吸附容量也有所提高;pH在5～7时,活性氧化铝的吸附容量大、除氟速率高;另外,活性氧化铝的加入量及原水氟浓度对除氟速率和吸附容量也有重要影响。     

聚硅酸改性对活性氧化铝除氟性能的影响

采用聚硅酸对活性氧化铝进行改性,研究了SiO2百分含量、聚硅酸浸泡时间、焙烧温度及焙烧时间对改性活性氧化铝除氟性能的影响。结果表明,改性活性氧化铝能将水中的氟离子浓度从9.5 mg/L降低到0.89 mg/L,吸附容量提高了30%。因此,聚硅酸改性能有效提高活性氧化铝的除氟性能。     

氧化锰涂层活性氧化铝除氟性能研究

通过化学改性处理,生成氧化锰涂层活性氧化铝(MOCA).X射线衍射(XRD)分析和扫描电镜观测表明,在氧化铝表面形成了针状的δ-二氧化锰,MOCA表面涂锰量为58mgMn/gAl2O3,试验数据揭示MOCA氟吸附遵循二级反应速率模型,吸附过程符合Langmuk等温方程,pH值对MOCA氟吸附性能影响显著,MOCA氟吸附动水接触时间为3.92min.研究表明氧化锰涂层活性氧化铝(MOCA)具有良好的氟吸附性能.     

浅谈活性氧化铝对双氧水生产的影响

活性氧化铝在蒽醌法双氧水生产工艺中,主要作用是吸附工作液中夹带的碱以及再生工作液在氢化,氧化反应过程中因副反应产生的副产的,在双氧水生产过程中,怎样选择和用好活性氧化铝,对双氧水的产量和质量极为重要。     

压缩热再生干燥器活性氧化铝固体吸附剂的除湿性能

以活性氧化铝为吸附剂材料,选取5.5～6.5 mm及4～5 mm两种粒径的活性氧化铝对压缩空气进行除湿实验研究,为活性氧化铝在压缩空气除湿系统中的运行提供依据。结果表明：在温度120℃、压力0.2 MPa、流量40 m3/h的条件下,5.5～6.5 mm活性氧化铝的再生性能优于4～5 mm活性氧化铝;在温度120 ℃、压力0.7 MPa、流量15 m3/h的条件下,前期在1200 s时间内,两者的吸附速率都很快,后期4～5 mm粒径的活性氧化铝的吸附稳定性更好。在给定的工况条件下,5.5～6.5 mm活性氧化铝再生效果比4～5 mm活性氧化铝要好,但吸附效果不如后者。     

载镧活性氧化铝的除氟及再生性能研究

为研究载镧活性氧化铝对F-的吸附能力,文中实验利用浸渍法合成载镧活性氧化铝,分别探究吸附时间、pH值、吸附剂用量、干扰离子对吸附过程的影响,同时利用不同浓度的NaOH溶液对吸附剂进行再生,探究吸附剂的再生效果.结果表明:对于质量浓度为10 mg/L的F-溶液,吸附剂用量为5 g/L,其除氟效率为86％,酸性条件下有利于...     

活性氧化铝处理低浓度含氟废水的研究

通过静态实验,研究了活性氧化铝对氟离子的吸附性能,分析了活性氧化铝、投加量、吸附时间、pH值和废水温度对除氟的影响。研究表明,活性氧化铝的投加量与其吸附总量开始时基本呈线性增加的关系,但当活性氧化铝的量增加到一定量时其吸附总量将基本不再增加。当pH在3～5时,其吸附量最好,当温度增加时,其吸附总量在减少,振荡吸附时间为30 min时吸附基本达到平衡。     

胶粘剂及其用量对活性炭胶炭混合物液相吸附性能的影响

胶粘剂与粉状活性炭按不同的胶炭比混合、干燥、研磨得粉状胶炭混合物。测定了碘吸附值、亚甲基蓝脱色力和焦糖脱色力3种液相吸附力,讨论了原料活性炭、胶粘剂的种类和用量对活性炭成型物液相吸附能力的影响。结果表明胶接过程中,原料活性炭液相吸附力的劣化按碘吸附值、亚甲基蓝脱色力、焦糖脱色力的顺序而变得越来越严重,并随所使用胶粘剂分子质量的减小和用量的增加而加剧;原料活性炭的碘吸附值的损失率一般不超过10%,而焦糖脱色力的损失率几乎都达到了100%。用本方法制备的活性炭成型物的液相吸附特征是:适于吸附碘之类的小分子,具有在一定范围内可调整的较低的亚甲基蓝脱色力,而对焦糖色素之类的液相大分子的吸附力几乎为零。     

THE INFLUENCE OF OXYGEN ON THE ADSORPTION OF METAL CYANIDES ON ACTIVATED CARBON

Activated carbon adsorbs insignificant quantities of oxygen from aerated water. This consumption is increased drastically during the adsorption of anionic metal cyanides. The equilibrium loadings of gold and silver cyanides increased with an increase in the level of dissolved oxygen. However, for both gold and silver cyanides an oxygen concentration occurred above which the metal loading showed no further increase. FTIR scans were used to confirm the presence of AuCN and Au( CN)₂ on the loaded carbons. It was suggested that gold and silver cyanides adsorb in two ways: ( 1) where oxygen is consumed for the oxidation of the active sites, and ( 2) where adsorption takes place without the use of oxygen. A multicomponent Freundlich-type isotherm proved to be adequate in predicting the equilibrium metal loadings for the competitive adsorption of gold and silver cyanides on activated carbon. The level of dissolved oxygen did not affect the competition between these two solutes significantly.     

不同晶型氧化铝除氟性能与再生对比试验研究

对3种除氟用氧化铝的除氟与再生性能进行了对比试验研究。X射线衍射仪显示这3种氧化铝结晶度较低,晶型分别为γ-AlOOH、η-Al2O3和过渡形态氧化铝;电镜扫描仪显示3种氧化铝表面孔隙数量与晶粒形状各不相同。静态吸附试验结果表明,晶型对氧化铝的除氟及再生性能有决定性作用,不同晶型氧化铝的吸附量存在差异;这3种氧化铝经过再生处理后,可基本恢复原有的除氟性能,但是再生剂的酸碱性影响再生效果,晶型不同的氧化铝适用的再生剂不同。     

活化条件对沥青基球状活性炭结构与吸附性能的影响

研究了不同活化条件对沥青基球状活性炭表面物理结构的影响,并初步探索了其作为医学吸附材料对维生素B12及肌酸酐的吸附性能。结果表明：改变活化条件,可在一定范围内控制沥青基球状活性炭的孔径;在实验条件下,沥青基球状活性炭对维生素B12及肌酸酐的吸附率分别达到80％及96％。     

成型工艺条件对活性炭甲烷吸附性能的影响

以ＫＯＨ活化的粉状高比表面积活性炭为原料,羰酸甲基纤维素为粘结剂,制得了一系列高比表面积成型活性性炭,考察了成型压力、粘结剂添加比例及热处理等重要成型工艺条件对型炭甲烷吸附性能的影响。     

DYNAMIC MODELLING OF WATER VAPOR ADSORPTION BY ACTIVATED ALUMINA

Prediction of water vapor adsorption by activated alumina in a packed bed operated adiabatically is accomplished through the use of a simplified mathematical model. The model accounts for the heat and mass convection in the axial direction, and characterizes the heat and mass transfer associated with the adsorption process by a linear driving force. A linear isotherm was applied to approximate the equilibrium relationship of water vapor on activated alumina. Experimental data using Alcoa's commercial activated alumina, obtained from a 6 x 48 inch adiabatic column, were compared with model prediction; and a reasonably good agreement between these two was obtained. @KEYWORDS: Mathematical modeling, Adsorption, Activated alumina, Gas drying, Desiccant, Packed column.     

ADSORPTION ISOTHERMS AND HEATS OF IMMERSION IN THE ADSORPTION OF BINARY MIXTURES ON ACTIVATED CARBON

The surface excess and the heat of immersion in the adsorption from binary mixtures on the active carbon surface were calculated in terms of the concentrations of adsorbed phase, the adsorption capacity ratios and the heats of immersion of pure compounds. The surface concentrations of binary mixtures were obtained from the thermodynamic model incorporating the intermolecular interactions between the surface and bulk molecules, and a model for surface activity coefficient considering the orientational states of adsorbed molecules, and the UNIQUAC equation. The calculated adsorption isotherms and heats of immersion were fair agreement with experiments of various binary isotherms.     

铁炭联用修复硝酸盐污染地下水

针对地下水中硝酸盐污染,提出了废铁屑与颗粒活性炭联用,开展了修复模拟硝酸盐地下水的批试验研究.结果表明,铁炭总量为8.0～10.0 g时,残留NO3-为34.23～35.21 mg·L-1,此时介质用量为最佳值.介质粒径对NO3-去除效果的影响不明显.反应时间从1 h增至5 h,水相pH由初始值6.42增至7.09.中性时铁炭联用可以保持水相pH的稳定.在弱酸性条件下,只有特定的金属氧化物对NO3-去除具有促进效果,5种氧化物均导致水相中NO2-和NH4+增加.铁炭联用的修复机理包括化学还原、原电池反应、絮凝(共)沉淀、电泳富集和吸附,是一种经济有效修复硝酸盐地下水的方法.     

CAPACITY OF ACTIVATED SLUDGE SOLIDS FOR VIRUS ADSORPTION

The first significant reduction in wastewater virus concentration occurs in the biological treatment process, either by removal of solid matter in which virus is embedded or by adsorption of virus to the biomass. In addition, the effectiveness of subsequent disinfection and the ultimate fate of treatment plant effluent virus are dependent on the extent of virus association with small suspended particles. This report is a study of adsorption of Type I poliovirus to solids collected from an activated sludge unit and resuspended in filtered final effluent. Virus adsorption capacity was correlated by an isotherm relationship which includes the effect of decreasing capacity with increasing solids concentration. This effect is probably caused by decreased solids surface area due to solids aggregation. The results indicate smaller capacity at typical activated sludge mixed liquor solids concentration than would be predicted from previous studies, and that only about 20% of total virus are adsorbed at low solids concentration typical for treatment plant effluent.