溶剂气浮法分离甲基异丁基酮模拟废水

采用溶剂气浮法对含弱疏水性、有一定挥发性甲基异丁基酮(MIBK)的模拟废水(0.20%, j)进行了分离研究. 考察了气浮时间、氮气(N2)体积流速、油水相体积比、共溶质及表面活性剂等对MIBK溶剂气浮分离效率的影响,获得了各参数的优化结果. 结果表明,当N2流速为40 mL/min、油水相体积比为1:30、氯化钠浓度为0.50%(w)、乙醇浓度为1.0%(j)时,溶剂气浮法对模拟废水中MIBK的分离效率可以达到25%~30%左右,而表面活性剂对提高溶剂气浮分离效率作用非常有限,仅在-10%~5%范围内.     

司盘-80辅助回流法提取红藤中的黄酮类物质

采用表面活性剂辅助回流法提取红藤中的黄酮类物质,考察了表面活性剂的种类、浓度,液料比,溶剂pH值以及回流时间等因素对红藤中黄酮类物质得率的影响,并用正交实验确定最佳工艺条件为：司盘-800．007g／mL,液料比50mL／g,溶剂pH值为6,回流时间60rain,此时红藤总黄酮的得率为19．5％。与传统水提法相比,得率提高了92．74％。     

泡沫分离法提取乙醇水体系中甲基橙

采用泡沫分离法对含甲基橙的乙醇水溶液进行了提取研究. 考察了乙醇体积分数、气体流量、pH、甲基橙浓度和表面活性剂浓度对提取效果的影响,并对泡沫分离乙醇-水体系中提取中药有效成分的可行性进行了探讨. 结果表明,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,在乙醇体积分数25%的乙醇-水体系中,在pH 6.0、气速80 mL/min、甲基橙浓度35 mg/L及CTAB浓度80 mg/L的操作条件下,甲基橙的富集比为14.38,回收率在98.5%以上. 在一定范围内提高表面活性剂浓度或加入稳泡剂以削弱乙醇的消泡作用,从而将泡沫分离技术应用于乙醇-水体系中中药有效成分的提取是可能的.     

泡沫分离法处理结晶紫染料废水的工艺

以结晶紫模拟染料废水为研究体系,对泡沫分离法脱除结晶紫染料废水色素的工艺进行了研究,考察了以表面活性剂十二烷基苯磺酸钠(SDBS)为捕收剂时,pH、气体流速、表面活性剂浓度、装液量对脱色效果的影响,利用正交实验确定了优化操作条件. 结果表明,当pH为11.0、气速0.018 m3/h、SDBS浓度450 mg/L、装液量500 mL时,富集比为10.3,废水中结晶紫脱色率为93.5%.     

泡沫分离法处理甲基橙染料废水工艺

为开发一种设备和工艺简单、成本低且不产生二次污染的染料废水处理方法,以甲基橙模拟染料废水为研究体系,对泡沫分离法脱除甲基橙染料废水色素的工艺进行了研究。研究了pH值、气体流速、表面活性剂质量浓度、装液量对脱色的影响,以表面活性剂十六烷基三甲基溴化铵(CTAB)为捕收剂,确定的最佳操作条件为:pH值6.0,气速0.04 m3/h,CTAB质量浓度90 mg/L,装液量1 000 mL,第1次脱色富集比β为111.0,脱色率R为99.5%。然后,对破沫液进行过滤,所得的滤液可代替部分表面活性剂进行下一次脱色。当补加的表面活性剂与废水中甲基橙的摩尔比为0.89∶1时,第2次脱色率为99.4%,富集比为50。     

消泡剂共存体系中泡沫分离蛋白质

在以牛血清白蛋白(BSA)为目标蛋白、聚环氧丙烷环氧乙烷甘油醚(PGE)为消泡剂的模拟体系中,考察了表面活性剂种类(非离子型Tween-20和离子型SDBS)、浓度、溶液pH及操作参数(气体流量、初始液池高度)对BSA分离效率的影响. 结果表明,2种活性剂均能改善模拟体系的泡沫性能,使泡沫分离. 后者作用更强并能促进BSA的吸附,因DBS-通过静电作用与带相反电荷的BSA结合形成疏水性更强的BSA-DBS复合物. pH通过影响BSA的电荷分布而影响其与SDBS的结合,进而影响对BSA的吸附,初始BSA浓度0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, pH为3.4时,约66%蛋白质浓缩在泡沫液中,富集比为5.34. 增加气速或初始液池高度可得到较高收率,但富集比减小.     

超声空化-表面活性剂水溶法提取RDX/Al/AP/HTPB炸药中的AP

为了对RDX/Al/AP/HTPB炸药的有效成分进行分离回收,研究了以超声空化-表面活性剂水溶法提取RDX/Al/AP/HTPB炸药中高氯酸铵(AP)的分离工艺,探讨了各工艺参数对AP提取率的影响。结果表明,表面活性剂浓度、提取时间和超声频率是影响AP提取率的主要因素,表面活性剂种类为次要因素,料液质量比和提取次数对AP提取率的影响很小。最佳工艺条件为:室温,提取时间40min,料液质量比1∶3,提取次数1次,超声功率3.0kW,表面活性剂为吐温80(质量分数2.0%)。     

虎杖中白藜芦醇超声波提取工艺

本实验利用超声仪对虎杖中白藜芦醇进行提取,对提取时间,提取温度,溶剂浓度,缓冲液pH,料液比先进行单因素实验,通过正交实验确立了最佳条件为:pH=8,料液比=1/70,溶剂浓度=50%,提取时间=45 min,提取温度=50℃。     

银杏叶黄酮类化合物提取方法的研究

对纤维素酶预处理和甲基化β-环糊精溶液相结合提取银杏叶总黄酮的工艺进行了探讨,考察了料液比、酶浓度、温度、时间及pH值对酶解效果的影响,以及M-β-环糊精浓度、温度和时间对浸提效果的影响。得到最佳酶解预处理条件为：经料液比（银杏叶质量与纤维素酶溶液体积之比）1／60、酶质量浓度0．2mg／mL、酶解温度40℃、酶解介质pH=6．5、酶解时间150min处理后,在M—β-环糊精质量分数2．0%、温度60℃条件下浸提180min,总黄酮得率可达2．68％。该工艺为银杏叶黄酮类化合物提取提供了新途径,同时避免了有机溶剂的使用,便于纯化,值得推广。     

液膜法提取分离对氨基苯甲酸的研究

由磷酸三丁酯(TBP)、表面活性剂和煤油为油相,氢氧化钠溶液为内水相,含对氨基苯甲酸(PABA)的水溶液为料液(外水相),组成了W/O/W型乳状液膜体系,用乳状液膜法对料液中的PABA进行了分离富集研究。探讨了PA-BA在水中的形态分布及其液膜分离的传质机理,考察了表面活性剂种类、TBP质量分数浓度、外水相pH值和内水相氢氧化钠浓度等因素,对PABA传质分离的影响。结果表明,采用适宜的乳状液膜体系,在最佳的操作条件下,对含PABA浓度为500 mol/L的料液进行分离富集时,仅经一级液膜分离过程,PABA的分离提取率可达99%。     

红景天苷的溶剂浮选

建立了一种测定红景天苷的新方法,即采用溶剂浮选法分离富集红景天苷,用紫外分光光度法测定其含量.考察了浮选溶剂、试液pH、氮气流速、浮选时间及电解质NaC1等因素对浮选效果的影响,优选出最佳浮选条件.采用所述方法对不同前处理样品中红景天苷含量进行测定,样品加标回收率为99.71％～104.21％,RSD为1.6～2.21...     

Studies on the Removal of Bromocresol Green from Water by Solvent Sublation

Abstract

Bromocresol green (BG) was removed from an aqueous solution by solvent sublation of bromocresol green–hexadecyl‐pyridiumchlorid (HPC) complex (sublate) into 2‐octanol. The effects of many parameters, such as the amount of surfactant, airflow rates, pH, NaCl, and ethanol on the solvent sublation were studied. Different temperatures of the solvent sublation were also investigated. A ratio of surfactant to dye (1.25:1) was the most effective for the removal, with over 99% BG removed from the aqueous solution within 5 min. The removal rate was somewhat enhanced by higher airflow rates and almost independent of the volume of the organic solvent floating on the top of the aqueous column. The effects of electrolytes (e.g. NaCl) and non‐hydrophobic organics (e.g. ethanol) reduce the removal efficiency of solvent sublation. This process followed first order kinetics. A characteristic parameter, apparent activation energy of attachment of the sublate to bubbles, was estimated at a value of 1.3 kJ/mol. Furthermore, the simulation of the mathematical and experimental data was made with good results.     

气泡直径对溶剂气浮分离废水中乙酸丁酯的影响

采用溶剂气浮法,以正壬烷为上层捕收溶剂,对0.40%(j)乙酸丁酯模拟废水进行分离,考察了气浮时间、气体流量、油水相体积比等对乙酸丁酯溶剂气浮分离效率的影响,特别是不同尺度气泡对溶剂气浮过程的影响. 结果表明,当油水体积相比为1:25时,平均直径为0.6 mm的气泡采用的通气流量为20 mL/min、平均直径为0.2 mm的气泡采用的气流量为1.67 mL/min的最终分离效率均可达60%,但分离时间、总气量及溶剂对水相的二次污染均有较大差别.     

Removal of Traces of Pentachlorophenol from Aqueous Acidic Solutions by Solvent Extraction and Solvent Sublation

Abstract

The removal of pentachlorophenol (a hydrophobic compound of low vapor pressure) from aqueous acidic solutions was studied using solvent sublation (a surface chemical technique) and solvent extraction. Both methods gave appreciable removals in highly acidic solutions (pH = 2.5), but solvent sublation had the added advantage of minimal phase contact of the organic solvent with water and increased removals under certain circumstances. Solvent sublation was also found to be more effective than conventional fine bubble aeration. The removal of pentachlorophenol (PCP) was considerably smaller at pH's near the pK_a of PCP. PCP removal by solvent sublation was enhanced by increasing ionic strength and also by the presence of small amounts of an ionic surfactant in the aqueous phase. The technique of solvent sublation was tried on an actual wastewater sample from a wood preserving industry. pH adjustment, removal of suspended solids, addition of sodium chloride, and subsequent solvent sublation into mineral oil reduced the PCP concentration in the aqueous waste by 99.7%.     

Studies in Batch and Continuous Solvent Sublation. IV. Continuous Countercurrent Solvent Sublation and Bubble Fractionation of Hydrophobic Organics from Aqueous Solutions

Abstract

Experimental results on the solvent sublation of four hydrophobic compounds [pentachlorophenol (PCP), 1,2,4-trichlorobenzene (TCB), 2,3,6-trichloroanisole (TCA), and 2,4,6-trichlorophenol (TCP)] from the aqueous phase tc organic solvents are reported. The experiments were conducted with the aqueous and air phases in continuous countercurrent modes and the organic solvent as a stagnant layer. TCB, TCA, and TCP were sublated into mineral oil. PCP at pH 2.9 as neutral molecules were sublated into mineral oil and decyl alcohol while ionic PCP at pH 8.9 were sublated as a complex with hexadecyltrimethyl ammonium bromide into decyl alcohol. The effect of the two organic solvents were compared for neutral PCP sublation from the aqueous phase. The effects of air flow rates, influent feed rates, and the volume of organic solvent were studied. Comparisons were made between the bubble fractionation and solvent sublation of neutral PCP and TCP into mineral oil. The efficiency of sublation was largest for TCB, smallest for TCP, and followed the relative magnitudes of “effective” partition constants for the solutes between the air bubble and aqueous phase.     

Removal of Organophosphorus Pesticides from Aqueous Solution by Using Adsorptive Bubble Separation Techniques

Abstract

Two organophosphorus pesticides, ddvp (phosphoric acid 2,2-dichlorovinyl dimethyl ester) and phorate (phosphorodithioic acid o,o-diethyl s-[(ethylthio)methyl] ester) were removed from aqueous solution by three adsorptive bubble separation techniques: air stripping, solvent sublation, and adsorbing colloid flotation. The effects of pH, flow rate, surfactant, ethanol, ionic strength, and coprecipitant concentration on the efficiency of pesticide removal were studied. Over 97% of phorate was removed in 30 min by solvent sublation, and 90% of phorate was removed in 10 min by adsorbing colloid flotation with Fe(OH)₃, floc. The separations of ddvp by these techniques were not effective.     

Removal of trace Cu from aqueous solution by foam fractionation

A system for removal of Cu²⁺ from aqueous solution by foam fractionation is proposed. The effects of pH, gas flow rate, surfactant concentration and froth/solution ratio on the removal rate and the enrichment ratio were studied to optimize the conditions. The results show that the removal rate increased with gas flow rate decreased, surfactant concentration increased and the froth/solution ratio increased, and was higher at pH4.0-5.0 than at other pH value. The optimum separation conditions were pH5.0, 200 mL/min of gas flow rate, 0.15 g/L of surfactant concentration and 1.1 of froth/solution ratio. Under the optimum conditions, the removal rate was 97.2% and the enrichment was 53.0.     

pH法监测MEA溶液吸收CO2反应进程

乙醇胺(MEA)溶液对CO₂等酸性气体具有良好的吸收效果,在气体分离与净化等领域有较好的应用前景。通过酸度计对MEA水溶液吸收CO₂过程中pH的变化进行实时监测,综合考虑了溶液浓度、原料气流量、温度对反应速率的影响,引入描述吸收性能的比催化活性概念。实验结果表明:随着溶液浓度增加,pH下降速率不断降低,饱和时间逐渐延长,饱和状态的pH不断提高;随着CO₂进气流量的增加,溶液pH下降速率逐渐提高并最终保持不变,溶液饱和时间逐渐缩短,饱和状态的pH随着流量的增加先降低后升高,在70 ml·min^-1进气流量下pH达到最低;随着溶液温度升高,pH下降速率先增加最终趋于稳定,饱和时间逐渐缩短最终趋于一致。该法操作简单,监测准确,并可以为CO₂吸收液的研发提供参考。     

Novel Gas-assisted Three-liquid-phase Extraction System for Simultaneous Separation and Concentration of Anthraquinones in Herbal Extract

abstract Gas-assisted three-liquid-phase extraction (GATE), which has the advantages of both three-liquid-phase extrac-tion and solvent sublation, is a novel separation technique for separation and con...     

APPLICATION OF SOLVENT SUBLATION TO THE SIMULTANEOUS REMOVAL OF EMULSIFIED COAL TAR AND DISSOLVED ORGANICS

Solvent sublation is a unique bubble-separation method which combines features of foam fractionation and solvent extraction in a single unit operation. Surfactant introduced into a flotation column serves to remove emulsions and other colloids, while simultaneously transporting dissolved organics into a solvent layer for retention. The extracting solvent is placed directly on the surface of the aqueous phase.

The objective of this research was to test the feasibility of using the solvent sublation process to remove phenols and particulates from underground coal gasification (UCG) wastewater. Previous work with separate flotation, adsorption, solvent extraction and coagulation processes indicated that a combined approach might have added utility in increasing pollutant removal. Further, the combined process could have greater efficiencies of operation.

All experiments were performed in the batch mode using methylisobutyl ketone (MIBK) solvent and ethylhexadecyldimethylammonium bromide (EHDA-Br) surfactant. The solvent-aqueous ratios, pH, and surfactant doses were independently varied in this investigation, while the air flow rate was held constant. The final process configuration employed removed 93 percent of the phenols and over 90 percent of the 2-10 μm diameter particles from the UCG wastewater. In addition, some precipitate flotation was observed in select operational modes. This served to remove color bodies and additional colloids previously immune to treatment. Measurement of residual MIBK in effluents showed that solvent-sublation left less residual solvent than did solvent-extraction in these wastewaters.