The selection of a surfactant for freshwater microalgae harvesting and separation by the foam separation method

Abstract(#br)Collecting microalgae from water with less energy and cost is significant to gain economic profit from microalgae harvesting and processing. Foam separation has certain advantages including low energy consumption, simple operation and easy maintenance of the equipment. Natural surfactants, compared to traditional surfactants, were used to harvest and separate the freshwater microalgae Desmodesmus brasiliensis by foam separation. Results showed a recovery percentage of 93.6% and an enrichment ratio of 23.1 with the natural surfactant cocamidopropyl betaine (CAPB), suggesting that this low-cost surfactant can be applied to microalgae biomass recovery on a commercial scale using foam separation with no negative effect on the content of microalgae chlorophyll, carotenoid or..

Study on the Extraction Technology of Candida antarctica Lipase B by Foam Separation

Candida antarctica Lipase B (CALB) has a wide range of applications in many fields. In this study, Pichia pastoris was used to express CALB for fermentation tank culture. Sodium dodecyl sulfate (SDS) was used as a surfactant, and foam separation technology was used to explore the best experimental conditions for the harvest of CALB. The results showed that the optimal technological conditions for the foam separation and recovery of CALB were as follows: liquid volume was 150 mL, separating gas velocity was 600 mL/min, pH value was 7, and surfactant SDS concentration was 0.5 mg/mL. Under these conditions, the enrichment ratio of CALB was 0.95, and recovery rate R was 80.32%, respectively, indicating that the foam separation technology is feasible to extract lipase B

Application of foam separation in production of β-glucanase in Pichia

β-glucanase is widely used in many fields and has great economic value and development space, but it faces the difficulties of separation and nutrient destruction in the process of industrial production. Foam separation is a simple, mild and efficient adsorption separation technique that enables efficient separation and extraction of β-glucanase. In this study, five single factors(loading volume, pH, separation gas velocity, fermentation loading concentration, surfactant concentration) of foam separation and harvest of β-glucanase produced by Pichia pastoris were studied. The best univariate condition was: 600 mL/min separation gas velocity, loading volume of 200 mL, initial enzyme concentration of 100 g/mL, surfactant concentration of 0.3 mg/mL and pH of 5. Based on the best univariate condition, the optimal separation conditions of β-glucanase were further explored, and the five-factor four-level orthogonal test was designed. From the experimental results, the best separation condition was: 600 mL/min, loading volume of 200 mL, initial enzyme concentration of 100 μg/mL, surfactant concentration of 0.5 mg/mL and pH of 5. Under this separation condition, the enrichment ratio (E) was 0.56 and the recovery rate (R) was 96.01%

Microencapsulation of Algal Oil Using Spray Drying Technology

This work aims at developing a process of microencapsulation of algal oil containing ≥40 % docosahexaenoic acid (DHA) using spray drying technology. Purity Gum® 2000 and Capsul®, both obtained from waxy corn starch, were chosen as the encapsulation materials. The effects of emulsification conditions on the droplet size, stability, viscosity and surface tension, and the effects of spraying conditions on the particle size, moisture content and surface oil content were investigated successively. The morphology of emulsion droplets and the microcapsules was observed by optical microscope and scanning electron micro scopy. The results showed that the produced spherical microcapsules were smooth and free of pores, cracks, and surface indentation when shear velocity was 8.63 m/s in the first step of emulsification, homogenization pressure was 1.75·10˄8 Pa and number of passes through homogenization unit was six for fine emulsification, rotational speed of spray disk was 400 s-1, and air inlet temperature was 170 °C. Therefore, it was concluded that the emulsification and encapsulation of algal oil containing DHA with above process was feasible

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

Fundamental Research Funds for the Central Universities; Fujian Science and Technology Committee [2013H0043]; Xiamen Science and Technology Committee [3502Z20123005]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 0.18mg/mL, air flow rate 50mL/min, liquid loading volume 200mL, pH 5.5, and operating time of 2h. A two-stage foam fractionation technology was also designed, which was effective for improving both the recovery percentage and enrichment ratio simultaneously

The separation of microscale HA in aqueous solution by foam separation technique

Hyaluronic acid (HA) has important applications in fields of health care products, cosmetics and clinical medical. However, the unique physiological properties of HA make cost of its traditional separation and extraction process relatively high. Foam separation technique has simple, gentle and efficient advantages on the separation of substances with surface activity by using bubbles as the separation medium. In this paper, natural surfactant CocamideBetaine (CAPB) was used as a foaming agent to explore the technology of microscale HA in aqueous solution by foam separation. The optimum process conditions were determined based on the recovery rate and enrichment ratio of HA by single factor and orthogonal experiment: at room temperature, pH = 7, separating air velocity (v) = 350 mL/min, HA concentration (CHA) = 50 mg/L, adding liquid volume (V) = 200 mL, collecting time (tcol) = 10 min, CAPB concentration (CCAPB) = 0.035 g/L. Under these conditions, HA enrichment ratio (E) equals 6.821 and HA recovery rate (R) equals 66.425%

The separation of microscale HA in aqueous solution by foam separation technique

Hyaluronic acid (HA) has important applications in fields of health care products, cosmetics and clinical medical. However, the unique physiological properties of HA make cost of its traditional separation and extraction process relatively high. Foam separation technique has simple, gentle and efficient advantages on the separation of substances with surface activity by using bubbles as the separation medium. In this paper, natural surfactant CocamideBetaine (CAPB) was used as a foaming agent to explore the technology of microscale HA in aqueous solution by foam separation. The optimum process conditions were determined based on the recovery rate and enrichment ratio of HA by single factor and orthogonal experiment: at room temperature, pH = 7, separating air velocity (v) = 350 mL/min, HA concentration (CHA) = 50 mg/L, adding liquid volume (V) = 200 mL, collecting time (tcol) = 10 min, CAPB concentration (CCAPB) = 0.035 g/L. Under these conditions, HA enrichment ratio (E) equals 6.821 and HA recovery rate (R) equals 66.425%

Cover Picture: Plasma Process. Polym. 7/2017

Front Cover: A facile strategy by using atmospheric pressure dielectric barrier discharge (AP-DBD) with tetraethoxysilane (TEOS)/Ar/O2 as the source gas is employed for siloxane film deposition (upper). The composition of deposited siloxane film can be tuned by oxygen content in the working gas. The deposited siloxane film shows good stability and high surface resistivity, and reduces the odds of partial discharge, which is promising for power transmission application (below). Further details can be found in the article by Ruixue Wang et al. on 1600248