Characterization and separation of Al13 species using gel-filtration chromatography

A polyaluminum chloride (PAC) sample was prepared using a slow alkaline titration method. The Bio-Gel P-100 gel column chromatographic technique was used to separate and characterize the various forms of aluminum present in the prepared PAC solution. The effluents from a gel column were monitored using online chemical method: Al-Ferron timed complexation spectrophotometry and by ²⁷Al nuclear magnetic resonance (NMR) spectroscopy. Effects of different experimental conditions such as eluent flow rate, ionic strength and pH on separation of Al₁₃ were investigated. Experimental results indicated that molecule size exclusion was not the only parameter affecting the column chromatographic separation efficiency of Al₁₃ but molecule charge as well. Reducing the eluent flow rate, increasing the ionic strength and suitable pH resulted in increase in the separation efficiency. Experimental results clearly indicated that by varying the experimental conditions, it is possible to produce pure Al₁₃ species using a gel column chromatographic technique.     

Characterization and separation of Al_(13) species using gel-filtration chromatography

Polyaluminum chloride (PAC) coagulant has been developed and widely used in water and wastewater treatment industry since the 1980s[1]. PAC is normally made by partial hydrolysis of acid aluminum chloride solution using slow alkaline titration method. However, this method would result in many different Al species. Among these Al species, it seems that tridecamer (Al13O4(OH) 724 , often denoted by Al13) is the most effective and stable polymeric Al species for water and wastewater treatme…     

alb聚铝离子稳定性的温度效应及硫酸盐沉淀形态

alb聚铝离子;稳定性;温度效应;硫酸盐沉淀;al-ferron络合比色法     

聚碱式氯化铝制备实验探索

通过改进的制备方案,在常温下成功制备聚碱式氯化铝。无论在制备方法上还是在净水效果上,改进后的聚碱式氯化铝的制备方案都优于现有教材采用的实验方案。     

氢化物发生原子荧光法测定聚氯化铝中砷含量的不确定度评定

依据JJF 1059-1999，对氢化物发生原子荧光法测定聚氯化铝中的砷含量进行不确定度评定。建立了数学模型，对各不确定度分量进行了分析和量化。计算出相对合成标准不确定度为0．0095，扩展不确定度为0．032mg／kg。砷含量测量不确定度主要来源于测量样品测试液中砷浓度产生的不确定度。     

聚合氯化铝制备球形拟薄水铝石和γ-Al_2O_3的研究Ⅰ——制备条件探讨

采用实验室自制的聚合氯化铝为原料,结合溶胶-凝胶法和油滴法制备球形拟薄水铝石及其衍生物γ-Al2O3,采用XRD,TEM和N2吸附法对样品进行了分析表征,探讨了不同pH值、不同铝形态含量的聚合氯化铝、不同煅烧温度及不同表面活性剂对产物结构性质的影响。结果表明:pH值在8.5附近合成的水合氧化铝以拟薄水铝石为主;高Alc含量的聚合氯化铝有利于形成高比表面积的球形产物;在450～750℃下煅烧产物为球形γ-Al2O3,并且随温度升高,产物比表面积下降、孔径增大,孔容变化不明显,在1000℃下煅烧产物为球形θ-Al2O3与γ-Al2O3的混合物;随着聚乙二醇表面活性剂分子量的增加,所得球形γ-Al2O3的孔容和孔径增大,聚乙二醇10000的扩孔效果最好,450℃下煅烧所得球形γ-Al2O3的比表面积、孔容分别达326m2·g-1、0.55cm3·g-1。     

聚合氯化铝形态分布、分析和控制研究进展

Al^3 发生水解和聚合反应,形成多种形态。关于其形态分布与结构,目前存在两种观点,即六元环连续分布模式和聚十三铝模式。形态分析的方法,主要有NMR法、吸光光度法等。影响形态分布的因素,主要有反应物浓度、碱化度、碱液加入速度、加碱方式、混合状况等。     

钙对铝水解聚合反应及聚合铝物化特性的影响

The polyaluminum chloride containing Ca was prepared by adding Ca before and after the aluminium polymerization, respectively. The effects of Ca on the hydrolysis and polymerization of aluminum, the characteristic of aluminum species, the ζ potential and viscosity of PAC were also studied. The experimental results show that the introduction of Ca retards the formation of Al precipitates during the hydrolysis and polymerization of aluminum and increases the contents of Al_m and Al₁₃ in PAC. Aluminum species can complex with Ca to form heteronuclear hydroxo complexes, which decreases the chemical shifts of Al_m and Al₁₃ in NMR. The ζ potential and the viscosity of PAC increase with the rise of Ca/Al molar ratio. Comparing with adding Ca after the aluminium polymerization, there are much more Al-Ca heteronuclear hydroxo complexes formed by adding Ca before the polymerization, which leads to a more obvious influence of Ca/Al molar ratio on the ζ potential and the viscosity of PAC.     

纳米聚硅酸铝铁絮凝剂的制备和性能

以硅酸钠、氯化铁、氯化铝为原料通过超声的方法制备了无机高分子纳米级聚硅酸铝铁絮凝剂(Nano-PAFSI),考察了其投加量、pH值、搅拌强度等因素对废水处理效果的影响,并对混凝机理进行了分析.实验表明,产品纳米聚硅酸铝铁(Nano-PAFSI)比普通聚硅酸铝铁处理废水效果更佳.对印染废水的浊度去除率为97.8%,色度去除率为94.6%,CODCr去除率为55.1%.     

Investigation of dynamic processing on aluminum floc aggregation:Cyclic shearing recovery and effect of sulfate ion

The floc formation and re-aggregation potential and the effects of sulfate on coagulation by AlCl3, polyaluminum chloride (PAC), and Al13 species using a photometric dispersion analyzer (PDA) are in- vestigated. It is found that the recovery level from shearing is the highest for the Al13 species. This is likely a result of increased collision efficiency due to more effective charge neutralization. The ex- perimental results show that sulfate has a significant effect on coagulation and promoting aggregation of hydrolyzed species for the Al13 species. It results in significant improvement of the coagulation effi- ciency through an electrostatic patch effect. The results further indicate that zeta potential of the parti- cle suspension is not the only indicator for the coagulant efficiency when precipitate formation sig- nificantly improves coagulation.