溶气气浮法采收盐藻(Dunalilla salina)细胞

初步探讨了不添加絮凝剂和表面活性剂时用溶气气浮法采收盐藻细胞的工艺条件，结果表明，藻液pH值、溶气压(PS)、溶气水进水流量(QW)、溶气水/原料藻液体积比(水液比aWF)对采收效果有重要影响. 本实验条件下，调节藻液pH值为11.5, 在PS＝0.39 MPa, QW＝7 ml/s, aWF＝1.5的气浮操作条件下，细胞采收率和浓缩倍数分别达86.4%~96.4%和2.38~5.57. 表明气浮法可以安全、高效地从培养液中采收盐藻细胞，无需添加絮凝剂.     

螺旋藻泡载分离法采收的实验室研究

在一种斜臂泡沫分离装置上，较为详细地研究了泡沫塔构造、起泡剂Tween 20浓度、载气流率、pH值和乙醇浓度等因素对螺旋藻泡载采收性能的影响. 结果表明，斜臂泡沫塔可明显改善藻细胞的泡载性能, 当Tween 20浓度为100 mg/L、载气流率为30 L/h及pH=11、乙醇浓度为1%(j)时，泡载采收过程的分离因子R和浓缩倍数a可分别达到5.04~6.52和2.74~4.31.     

微藻细胞的连续泡沫分离法采收

为考察连续泡沫分离法采收微藻细胞的可行性 ,在一种斜臂泡沫分离装置上 ,以螺旋藻为模型藻种 ,较为详细地研究了载气流率、藻液进料流率、浓度、pH值、离子强度、乙醇浓度、进料位置、泡沫段与液相段高度之比等因素对泡载采收性能的影响。结果表明 :在载气流率、藻液进料流率或藻液浓度较低时采收性能良好 ;当 pH值为 11、离子强度为 1 3× 10 ⁴ μs·cm^-1、乙醇浓度为 3%(体积 )时泡载收率可达 2 5 %～ 45 %;采用泡沫相段进料有利于提高泡载采收性能。提出的连续泡载采收动力学模型与实验值拟合较好 .     

盐藻在气升式光生物反应器中的光自养培养

在气升式光生物反应器中进行了盐藻培养特性的研究，确定了盐藻在2.5 L气升式光生物反应器中培养的适宜条件为：温度30℃，光强1.6 mW/cm2，盐浓度16%，通气量20 ml/min. 扩大到20 L反应器培养盐藻生长良好. 采用气升式光反应器培养盐藻生长快，周期短，4~7 d后即可进入稳定期；最终细胞密度大，最大为1.6?106 cells/ml；藻液中胡萝卜素含量高，最高含量32 mg/L.实验表明气升式光生物反应器适合于盐藻的培养.     

能源微藻无泡采收新方法及其性能

采用低密度浮珠颗粒代替气泡的无泡采收方法,高效低成本采收能源微藻. 以常见能源微藻小球藻为例,以硅硼酸钠为浮珠,比较了浮珠浮选工艺与传统气浮法的区别,通过响应面法优化了浮珠浮选工艺. 结果表明,以硅硼酸钠为浮珠的无泡采收效果较理想,浮珠颗粒粒径、浓度和搅拌速率对采收率影响显著,颗粒直径56 ?m、浓度0.546 g/L、搅拌速率133 r/min的条件下采收率最好,达83.7%.     

从固体粗酶中提取α-淀粉酶的研究

本文以α-淀粉酶为研究对象，探索从固体粗酶侵取液中泡载浓缩α-淀粉酶的工艺过程．应用物料守恒原理对泡载分离过程进行了分析．实验分别考察了在浸取及泡载分离过程中酶活性的变化，提出了最优操作条件，并对酶的失活原因进行了探讨．     

能源微藻表面特性对其气浮采收效率的影响

选取小球藻与鱼腥藻为代表藻种,结合微藻的表面特性与XDLVO理论,研究了影响微藻浮选采收的关键因素,根据微藻表面的电负性,用阳离子表面活性剂C16TAB浮选两种藻.结果表明,pH为4~10时,两种藻的Zeta电位在-6.72~-15.01 m V之间,均显电负性;小球藻的黏附自由能为1.21 m J/m2,显亲水性,鱼腥藻的黏附自由能为-55.85 m J/m2,显疏水性.相同条件下,疏水性的鱼腥藻回收率始终高于亲水性的小球藻.小球藻和鱼腥藻在Zeta电位最大的pH处(分别为7和8)富集比最高(分别为12.45和1.3),而回收率在pH=10时最高,表明由于液膜的排液行为,回收率和富集比无法同时达到最大值.C16TAB对微藻表面疏水性有修饰作用,加入80 mg/L C16TAB后,小球藻疏水率从19%提高到64%,回收率提高了67.38%.     

循环水在不同浓缩倍数时总碱度的变化规律

为了对循环水的总碱度进行比较准确地监测和控制，在碳酸盐系统中，从化学热力学角度总结出一个总碱度与pH值的关系。根据不同水质标准自配置水样，采用鼓泡法，可测出冷却水在不同浓缩倍数下的总碱度和pH值。     

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.     

微藻采收技术的进展与展望

从微藻培养液的特性出发,总结了目前微藻采收工艺中预处理和富集分离阶段的各种方法,包括预氧化、化学絮凝、物理预处理、沉降、过滤、离心、泡载和气浮等. 已有研究结果表明,经预氧化处理后,细胞分泌胞外产物,有利于絮凝沉降,但药剂过量会引起细胞损伤甚至消亡;化学絮凝和物理处理可以大大提高后续富集分离的效率. 由于微藻培养液浓度低、粒度小,传统的沉降、过滤、离心等方法用于微藻的采收都存在效率低、成本高的限制,而气浮法适用于低浓度悬浮体系的富集分离,是微藻采收可行的技术途径之一.     

Cell and surfactant separation by column flotation

The separation of rehydrated Saccharomyces cerevisiae and an alkyl polyglycoside surfactant by column flotation was studied as a function of wash water flow and cation concentration. Separation of cells and surfactant was measured under steady-state conditions. Surfactant recovery in the foam concentrate was in the range of 86–95%. Yeast cells were enriched in the foam concentration by a factor of up to 11, but the recovery only reached 55%. The use of wash water was very effective for removing the cells from the foam, giving a good separation between the cells and the surfactant. Addition of chloride salts of Na, K, Ca, and Mg at concentrations in the range of 0.05-0.1 mol/L increased both the enrichment and the recovery of yeast in the foam. The most effective salt levels for cell flotation, less than 0.1 mol/L, were in the same range of concentration as the minimum electrophoretic mobility of the cells.     

强化泡沫排液下浮选富集和回收工程纳米颗粒

鉴于水体中工程纳米颗粒（ENP）的环境毒性与潜在价值,高效富集/回收ENP是其资源化处理的重要课题。为了突破浮选ENP中富集程度低且后续分离难度大的技术瓶颈,本文基于强化泡沫排液建立了富集/回收ENP的浮选法。以TiO₂纳米颗粒（TNP）为研究对象、十六烷基三甲基溴化铵（CTAB）为捕收剂和起泡剂,构筑了正八边形中空棱台（RHP）构件强化泡沫排液,分别从持液率、气泡直径和富集比等方面探讨了RHP强化排液的效果,分析了其机理。实验结果表明,在RHP构件安装于泡沫相中部、pH9.0、CTAB浓度100mg/L和气速250mL/min的条件下,TNP的富集比和回收率分别达到48.3±2.4和98.2%±4.9%;与不添加RHP相比,浮选过程中持液率降低了72.1%,TNP富集比升高了68.9%。综上,本文开发的浮选法为有效治理ENP水污染提供了重要的理论指导和技术支持。     

Foam fractionation for effective recovery of leaf protein from alfalfa (Medicago sativa L.)

ABSTRACT

Foam fractionation for recovering leaf protein from alfalfa (Medicago sativa L.) has been investigated. The extraction yield of alfalfa leaf protein (ALP) from the dried alfalfa leaves reached 71.90% under the extraction conditions of pH 8.0, temperature 70°C, and extracting time 40 min. For strengthening foam drainage at room temperature, a novel foam fractionation column with a cross-internal component covered superhydrophobic coating was developed. By using the extraction liquor as the feeding solution, a two-stage foam fractionation had been performed. Under the suitable operation conditions, the enrichment ratio and the recovery percentage of ALP were 4.33 and 89.0%, respectively.     

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.     

Foam separation of active carbon

An experimental investigation is presented of the foam separation of powdered active carbon, equilibriated with an aqueous, synthetic waste water containing phenol and a cationic (ethylhexadecyldimethylammonium bromide (EHDA-Br)), anionic (dodecyl sodium sulphate), or non-ionic (alkyl phenoxy polyethoxy ethanol) surfactant. The effect of surfactant, of pH, of initial carbon concentration, and of initial surfactant concentration on the flotation of carbon is investigated. At pH 3, 7, and 10, the cationic surfactant yields the best flotation of carbon, which increases with increasing pH. At pH 7, a suspension containing 800 mg/1 carbon can be reduced to 24 mg/1 in 10 min. with 0·37 mM EHDA-Br. The relative concentrations of carbon and of surfactant must be controlled carefully to yield sufficient free surfactant to obtain a foam but not excessive free surfactant to impair the foam separation process. Foam volumes are controlled by free (non-adsorbed) surfactant.     

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.     

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.