泡沫分离技术及其发展现状

泡沫分离技术是一项利用物质在气泡表面吸附性质的差异进行分离的技术。本文探讨了泡沫分离技术的原理、设备及其影响因素，并展望了泡沫分离技术的研究方向。     

泡沫塔吸附分离BF_4~-

<正>泡沫分离是以气泡为介质,以组分的表面活性差为分离依据的一种新型分离方法,在许多领域得到广泛的研究和应用’‘”’。本文采用泡沫分离塔装置,以十二烷胺醋酸盐（DAAC）为表面活性剂去除电镀废液中的BFi。本法与目前国内采用的加温条件下化学吸附沉淀法相比,具有设备简单、操作简便、耗能低、处理量大等特点。     

泡沫分离回收水中低浓度磷酸三丁酯

以吐温系列表面活性剂采用泡沫法回收水中的微量磷酸三丁酯．实验结果表明,在本实验条件下,泡沫法可以回收水中的磷酸三丁酯,磷酸三丁酯的提浓率与残留率与起始磷酸三丁酯浓度、起始表面活性剂浓度和表面活性剂种类有关。     

含十二烷基苯磺酸钠废水的多级泡沫分离研究

采用多级泡沫分离装置对水中十二烷基苯磺酸钠(SDBS)进行分离富集,考察了表面活性剂溶液的浓度、离子强度、pH值、分离时间、气体流速等因素对水中十二烷基苯磺酸钠脱除率的影响。进一步采用四因素三水平正交实验进行分离条件的优化,结果表明溶液浓度为20 mg/mL,气体流速为20L/min,pH=10,离子强度为2×10-5mol/L时,分离5 min,可使SDBS的脱除率最高达到97%,三次平行试验SDBS的脱除率分别为96.61%、97.04%和93.93%。与单级环流泡沫分离塔(其脱除率为82%)相比,多级泡沫分离装置具有能耗比低、分离效率高的优点,具有更好的推广应用价值。     

泡沫分离法的现状与研究进展

本文依据近年来有关泡沫分离的报道,介绍了泡沫分离的模型以及近年来的应用进展,并提出了若干需要深入研究的问题。     

泡沫分离-Fenton氧化工艺处理表面活性剂废水

采用泡沫分离-Fenton氧化工艺进行处理某炼油公司含SDBS和Brij30废水,研究了气体流速、废水流速、塔内液体高度、pH和Fenton试剂用量对处理效果的影响。得到了优化后的工艺条件为:Fenton试剂用量0.05 mol/L,气体流速0.054~0.072 m3/h,分离塔内液体量为1.8~1.9 L,废水流速2.0~2.2 L/h,Fenton氧化处理pH=3~4。在此最佳工艺基础上进行了工业侧线实验,实验表明,采用泡沫分离-Fenton氧化工艺可将废水中SDBS和Brij30分别降至2 mg/L和5 mg/L以下。     

泡沫分离技术的研究 Ⅰ.间歇法处理含锌废水

采用间歇式泡沫分离废水中的锌离子 ,探索了废水的 p H值、表面活性剂的投入量以及气体流量对分离效果的影响。实验证明 ,使用 SDS作为表面活性剂能有效地分离废水中的锌离子 ,处理后锌离子的脱除率可达 90 %以上 ,实验数据为连续化实验提供了依据。     

含铜和含锌稀溶液的吸附泡沫分离技术的研究

运用自制的泡沫分离塔,以十二烷基硫酸钠为表面活性剂对泡沫吸附分离含铜及含锌溶液的操作参数进行了研究。考察了料液浓度、pH值、气体流量、表面活性剂浓度等因素对含铜和含锌溶液泡沫分离效果的影响。结果表明：最佳操作参数为pH值5．0,料液浓度0．125mmol／L,进料流速50mL/min,气体流量100mL/min,表面活性剂浓度0．25mmol／L。同时从理论上推算出泡沫吸附分离铜离子的最佳pH值范围为5．0左右。实验还通过改变孔板的孔径大小以改变气泡的尺寸,特别研究了泡沫尺寸对泡沫吸附分离的影响。     

泡沫精馏塔内泡沫液的传质模型

本文对泡沫精馏塔内泡沫的传质问题进行了分析，提出传质微分方程，得到了解析解，并用实验验证了解的正确性。     

Coalescence of air bubbles in aqueous solutions of alcohols and nonionic surfactants

Coalescence of air bubbles in aqueous solutions of two aliphatic alcohols (viz. butanol and hexanol) and four nonionic surfactants (viz. Tween 20, Tween 40, Tween 60 and Tween 80) is reported in this work. Single-component alcohol and surfactant solutions as well as mixed binary surfactant–alcohol solutions were studied. Adsorption of the surface active compounds at air–water interface was studied by measuring the surface tension of the aqueous solutions. The critical micelle concentration and surface tension at this concentration were determined for the single and mixed surfactant–alcohol systems. The effect of concentration of surface active compounds on coalescence of air bubbles at flat air–water interface was studied. The role of electrostatic double layer, hydration and steric forces on coalescence was investigated. It was found that the stability of the thin aqueous films in mixed surfactant–alcohol systems depends on the subtle interplay of the intermolecular and surface forces in the film, which vary with the composition of the monolayer at the air–water interface. Stochastic distributions of coalescence time were observed in all systems. The coalescence time distributions were fitted by the stochastic model. The mean values of the distributions were compared with the predictions of seven film-drainage models.     

泡沫浮选分离技术应用进展

综述了泡沫浮选在分离固体粒子、分离溶液中的离子、分子,处理工业废水、油田开发、脱墨、土壤的清洗、回收、浓缩生物活性物质、分离全细胞的应用,并提出将来的发展方向。     

Removal of Trace Metal Impurities from Pretreated Phosphoric Acid by Foam Fractionation

Demands for phosphoric acid are growing rapidly in various industries. This has highlighted the importance of optimizing its production and purification methods. Phosphoric acid can be produced by a wet process. However, due to the presence of many organic and inorganic impurities in the wet product, purification of the resulting product is a major concern in this industry. Removal of trace metal impurities (such as magnesium, cadmium, chromium, zinc, etc.) from produced phosphoric acid in a wet process was investigated by foam fractionation in a semi-batch setup using sodium dodecyl sulfate (SDS) as the surfactant. Effects of inlet air velocity, surfactant concentration, and surfactant selectivity were investigated. The optimum air velocity and surfactant concentration were obtained as 0.020 cm/min and 0.7 g/L, respectively. At the optimum condition, the total removal efficiency and enrichment factor reached were 70.2% and 4.39, respectively, while the acid loss was 8.3%. The total metal removal efficiency was increased to 95.3% in a two-stage experimental run.     

泡沫分离方法回收钪

采用十二烷基聚氧乙烯琥珀酸单酯磺酸钠和十二烷基硫酸钠混合物作为表面活性剂，间歇式泡沫分离回收水溶液中的钪。讨论了料液pH值、表面活性剂浓度、鼓泡气流率、离子强度和操作时间等对分离效果的影响，得到了适宜的工艺条件。     

Fractionation of Nanocellulose by Foam Filter

The foam fractionation method was applied for nanocellulose. Experiments were carried out with enzymatically pretreated nano-fibrillated cellulose (NFC) from softwood, as well as commercial products. Narrow channels (plateaus) between bubbles prevent the flow of coarse particles along the water, so that foam acts like a filter. The advantage of the method is no risk of clogging, which could be a big problem for conventional filters or screens. Mean particle size (effective size by means of dynamic light scattering measurement) was reduced by foam fractionation, and the reduction range depended on the cellulose grade and the type of surfactant. The yield turned out to be low, probably because of particle aggregation due to the interaction with surfactant.     

Surfactant Recovery from Water Using a Multistage Foam Fractionator: Effect of Surfactant Type

Abstract

The purpose of this study was to investigate the recovery of surfactants using a multistage foam fractionator for three types of surfactants: cationic (cetyl pyridinium chloride, CPC); anionic (sodium dodecyl sulfate, SDS); and nonionic (polyoxyethylene(20 Princen , H.M. ; Mason , S.G. ( 1965 ) Shape of a fluid drop at a fluid-liquid interface I. Extension and test of two-phase theory . J. Colloid Sci. , 20 ( 2 ): 156 – 172 . [Google Scholar]) sorbitan monolaurate, Span80). The studied system was operated at a constant temperature of 25°C with a surfactant concentration in the range of 50 to 100% of CMC (critical micelle concentration). For any surfactant system, the enrichment ratio of surfactant increased with increasing foam height and number of stages but decreased with increasing effects of the air flow rate and feed concentration. For all studied surfactants, the removal efficiency of the surfactant was not significantly affected by changing the air flow rate, foam height, and feed concentration in the studied ranges. An increase in the number of stages showed a great improvement of both the enrichment ratio and the removal fraction for all three types of surfactants. In a comparison among the three studied surfactants, the separation performance, in terms of the enrichment ratio and removal was found to lie in the following order: CPC >Span80 > SDS, which can be explained by the foamability and foam stability of each surfactant.     

Separation of Extracellular Esterases from Pellet Cultures of the Basidiomycete Pleurotus sapidus by Foam Fractionation

Two extracellular esterases were produced in submerged cultures of the basidiomycete Pleurotus sapidus. A foam fractionation device was designed and employed for the isolation of the esterolytic enzymes. The recovery of enzyme activity in the liquefied foam strongly depended on the superficial gas velocity. High purification and enrichment factors (E _a = 62.0, P = 15.5) were achieved using nitrogen at 1.87 cm min⁻¹ within 100 min. Increasing the superficial gas velocity to 2.49 cm min⁻¹ improved the recovery of total esterase activity in the foam to >95% at the expense of reduced enrichment and purification factors. Differences in their physicochemical characteristics resulted in differing foaming properties of the two esterases secreted by P. sapidus. By variation of the pH value of the culture medium and addition of Triton X-100, both esterases were successively and quantitatively transferred into the foam in a two-step fractionation process.     

制备凝胶色谱在聚氨酯匀泡剂组成分析中的应用

用制备凝胶渗透色谱分离聚氨酯匀泡剂的混合组分,并对分离的组分进行了凝胶色谱、红外光谱等分析。对两个混合组分的聚氨酯匀泡剂的剖析结果进行了讨论。