Study on Riboflavin Recovery from Wastewater by a Batch Foam Separation Process

Abstract

A batch recovery of riboflavin via foam separation from industrial simulative wastewater was studied using a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB). The experimental parameters examined were the surfactant concentration, air flow rate, pH, and foam height. Under optimal operating conditions obtained through an orthogonal experiment, the maximum enrichment ratio of 48.7 was achieved for riboflavin along with 99.3% removal efficiency. The optimal operating conditions had the concentration of CTAB at 0.3 g/L, air flow rate at 400 ml/min, foam height at 90 cm, and pH at 12. Therefore foam separation proved to be an effective method to recover the riboflavin in terms of the good enrichment and removal efficiency.     

Separation of Tea Saponin by Two-Stage Continuous Foam Fractionation

A technology of two-stage continuous foam fractionation for tea saponin recovery was studied for increasing both the enrichment ratio and the recovery percentage. In the first stage, the effect of air flow rate, the initial pH, the feed flow rate, and the feed position were studied at a temperature of 60°C. The results showed that when the conditions of the first stage were at a temperature of 60°C, air flow rate 150 mL/min, pH 5.3, feed flow rate 1.92 mL/min, and feed position at the interface between the liquid phase and the foam phase, the enrichment ratio, and the recovery percentage of tea saponin were 4.02 and 56.4%, respectively, and the effluent solution was added to the second stage as the initial solution. When the conditions of the second stage were at a temperature of 30°C and an air flow rate of 300 mL/min, the recovery percentage of tea saponin reached 47.6%, and the foamate was added to the first stage as feed solution. The total recovery percentage of tea saponin reached 86.3% by the two-stage continuous foam fractionation.     

Purification and Concentration of the Total Saikosaponins Extracted from Radix Bupleuri using Foam Fractionation

The purpose of this study was to investigate the use of foam fractionation to recover saikosaponins. First, the solvent extraction method was applied for the extraction of saikosaponins from radix bupleuri using ethanol or deionized water. Then, the foam fractionation technique in batch mode was used for the recovery of the total saikosaponins from the extract. The effects of initial concentration, air flow rate, liquid loading volume, pH, and operating time on the process performance were investigated. The recovery percentage 77.2% and an enrichment ratio 3.68 of total saikosaponins with one-stage separation were obtained under the optimal conditions of initial saikosaponin concentration 0.18 mg/mL, air flow rate 50 mL/min, liquid loading volume 200 mL, pH 5.5, and operating time of 2 h. A two-stage foam fractionation technology was also designed, which was effective for improving both the recovery percentage and enrichment ratio simultaneously.     

Separation of Bovine Serum Albumin by Foam Fractionation with Sieve Tray Column

A batch foam fractionation column with sieve trays was developed for enhancing the foam drainage. Effects of feeding concentration, air flow rate, number of stages, and sieve pore size on foam fractionation performances were investigated. The results indicated that the sieve trays enhanced the foam drainage effectively and improved enrichment ratio. At the liquid loading volume 490 mL, feeding concentration 0.1 g L^?1, and air flow rate 300 mL min^?1, the enrichment ratio reached 7.56 by using 10 stages of sieve trays with opening ratio of 38.25%, which was 1.84 times of that obtained by the control column.     

泡沫分离法分离纯化无患子皂苷的研究

采用泡沫分离法分离纯化无患子皂苷溶液,收集溢出分离柱的泡沫液,采用紫外分光光度计分别测定原液和泡沫液的皂苷含量,通过富集比、回收率以及纯度表征分离效果。结果表明:在进料浓度为 2.0 g/L、进料量为 150 mL、气速为 32 L/h、温度为 30 ℃、pH值为4.3条件下,富集比可达到2.153,收率与纯度分别达到 79.19 % 和 74.68 %。     

红薯淀粉烷基多糖苷生产工艺研究

烷基多糖苷是新一代环境友好绿色表面活性剂,国外20世纪90年代才实现工业化生产。本文以红薯淀粉、乙二醇、十二醇为原料,以三元酸为催化剂,采用转糖苷法,在中试条件下成功合成烷基多糖苷。其较佳工艺条件为:m(红薯淀粉)∶m(乙二醇)∶m(十二醇)=1∶4∶1,高真空间歇反应(0.074 MPa),反应温度100~120℃。所得烷基多糖苷产品20℃时其表面张力为28.8~33.3 Nm/m,CMC=1.2×10-3mol/L,HLB值为18。红外、气质联用测定证明其确实为烷基多糖苷产品。该文报道工作的新颖性,已为中国科学院兰州查新咨询中心2006年1月9日出具的第200610906号《科技查新报告》所证实。     

泡沫分离法回收酶法生产生物柴油中的液体脂肪酶

采用泡沫分离法对酶法生产生物柴油过程中的水相脂肪酶进行回收并富集. 通过正交实验考察了液体脂肪酶溶液中pH值、通气速度、初始酶浓度对富集比、酶蛋白回收率和酶活回收率的影响. 结果表明,气速10 L/(L×h)、进料酶浓度0.2 g/L及pH 7.0时蛋白回收率和酶活回收率接近100%,相应的富集比为3.67;初始酶浓度对富集比和蛋白回收率有显著影响,回收过程中脂肪酶活性无损失. 甲醇的存在能显著提高回收速率,甘油的存在降低了富集比,而生物柴油的存在影响了泡沫的稳定性,要形成稳定的泡沫,生物柴油含量需小于0.01%.     

Study on Streptomycin Sulfate Recovery by Batch Foam Separation

The feasibility of foam separation as a technique was assessed for the recovery of streptomycin sulfate from the waste solution by using an anionic surfactant sodium dodecyl sulfate (SDS). The experimental parameters examined were SDS concentration, superficial gas velocity, initial pH, and liquid loading volume. The results showed that sodium dodecyl sulfate as the surfactant for foam separation had good foaming quality and could effectively concentrate streptomycin sulfate of the aqueous solution by technology of foam separation. The enrichment ratio and the recovery rate of streptomycin sulfate were 4.0 and 85%, respectively under the best operating conditions of sodium dodecyl sulfate concentration 0.4 g/L, superficial gas velocity 300 mL/min, liquid loading volume 300 mL and initial pH 6.0 when streptomycin sulfate concentration was 0.5 g/L.     

泡沫分离法分离人参皂苷

通过对浓缩倍数和收率的测定,考察了气速、pH值、进料浓度、进料量以及通气类型、操作方式等因素对人参皂苷泡沫分离效果的影响. 结果表明, 泡沫分离是分离浓缩人参皂苷的一种简便有效的方法.     

红薯淀粉烷基多糖苷生产的中试研究

用转糖苷法,以红薯淀粉、乙二醇、长链醇为原料,在2000L反应釜中生产了淀粉烷基多糖苷系列产品。工艺条件为m(红薯淀粉)∶m(乙二醇)∶m(长链醇)=1∶4∶1,残压小于9.3kPa,反应温度100～120℃。平均聚合度DP=1.10%,表面张力31.1～35.5mN/m,w(无机盐)<1.0%,w(固型物)>50%,w(活性物)>80%,w(游离脂肪醇)<1%。分析了刮膜除醇及氧化、还原脱色的生产工艺条件对产物的影响。用红外、气相色谱表征了产品。     

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%.     

Process optimization for foam separation of yak whey protein by response surface methodology

In order to recovery whey protein from yak whey wastewater effectively, a facile method of foam separation to be suitable for the local nomadic herdsmen in Qinghai-Tibet Plateau has been established in this research. The effects of the four factors, protein concentration, gas velocity, temperature and pH, on the performance of foam separation were investigated. Based on the single factor experiments, the response surface software was adopted to optimize and to investigate conditions of foam separation for whey protein, and the optimal conditions were found to be protein concentration of 120 μg/mL, gas velocity of 310 mL/min, temperature of 41°C and pH of 3.8, respectively. The as-obtained results of verification experiments, recovery percentage 88.3% and enrichment ratio 9.25 showed that foam separation technique was a simple equipment and environmental compatibility method to separate whey protein from yak whey wastewater.     

紫薯色素生产废水的生化处理研究

高紫色素品种的紫薯加工出的天然食用色素可以代替人工合成色素,在食品工业中已得到广泛的应用。但从紫薯中提取色素所产生的废水具有化学需氧量(COD)质量浓度高、色度大等特点,必须处理达标后才能排放。通过对特定微生物的驯化,使其降解该类废水,探讨其生化降解特性。实验结果表明,在好氧反应器内p H值约为5、COD的初始质量浓度约为1 600 mg/L条件下,利用好氧生物接触氧化法处理6 h后,废水的COD质量浓度可降至200 mg/L以下。     

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。     

泡沫分离技术在蛋白质多元体系分离中的应用

综述了泡沫分离蛋白质与糖,蛋白质与表面活性剂以及不同蛋白质的混合体系的研究进展,分析了泡沫分离技术在蛋白质分离中应用的前景并提出了需要解决的问题。     

微波辅助提取紫薯花青素的研究

文章以紫薯为原料,在微波条件下萃取其花青素,探讨了微波的辐射时间,温度,液固比,提取剂浓度对紫薯花青素萃取的影响,并采用大孔树脂AB-8纯化提取液,将纯化后的提取液进行反相高效液相色谱分析其成分。实验结果表明,紫薯花青素微波最佳提取条件为:辐射时间60 s,温度50℃,液固比40∶1,提取剂为1%HCl-95%乙醇溶液,最佳酸醇比为50∶50。     

温度对高浓度SDS水溶液泡沫稳定性及分离的影响

高浓度表面活性物质的分离是泡沫分离过程的难题,也是制约泡沫分离技术应用于工业化生产的瓶颈.为了解决高浓度表面活性物质泡沫分离的难题,以阴离子表面活性剂十二烷基硫酸钠(SDS)水溶液为体系,研究了在其临界胶束浓度(CMC)附近时,温度对SDS水溶液气泡直径、泡沫稳定性、富集比及回收率的影响.结果表明:温度对高浓度表面活性物质的泡沫分离有显著影响.当SDS水溶液浓度分别为1.2、2.3、3.5g·L-1,温度从30℃升高到70℃时,泡沫稳定性先增大后减小,在pH 6.9、表观气速2.4×10-3 m·s-1、装液量200 mL的操作条件下,气泡直径先减小后增大,富集比提高了3～5倍,回收率降低了34％～65％.     

红薯叶中黄酮类化合物的超临界提取研究

研究了超临界流体萃取红薯叶总黄酮的影响因素,并对生产工艺进行了优化设计。在单因素试验和正交试验的基础上,得到了红薯叶的超临界萃取工艺的最优化条件：萃取压力30 MPa,萃取温度50℃,夹带剂为80%乙醇,夹带剂用量为原料质量的50%,萃取时间150 min,CO2流量15 L/h。在此工艺条件下,黄酮得率为6.25%。     

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.