Recovery of Isoflavones from the Soy Whey Wastewater Using Two-Stage Batch Foam Fractionation

Abstract

The feasibility of recovering bioactive substances without surface activity from their aqueous solutions was studied using biosurfactants as collectors. For recovering the isoflavones from the soy whey wastewater, a two-stage batch foam fractionation was developed using the soy proteins as collectors. The results showed that when the conditions of the first stage were temperature of 60°C, pH of 5.0, volumetric air flow rate 80 of mL/min, and loading liquid volume of 400 mL, a high isoflavones enrichment ratio of 4.05 was obtained and the residual solution could be used as the feeding solution of the second stage. When the conditions of the second stage were temperature of 25°C, pH of 5.0, and volumetric air flow rate of 150 mL/ min, the soy proteins concentration in the residual solution could decrease to 622 mg/L. By reusing the foamate of the second stage as the feeding solution of the first stage, the total isoflavones recovery percentage reached 87.72%.

Construction binders and environmental indicators of their production

“…The production of low-clinker and zero-clinker cements is noteworthy. They can be obtained from the waste [12][13][14][15] containing calcium oxides. The decarbonization process was realized in the previous production.…”

Isolation of soy whey proteins from isoflavones in the concentrated solution using foam fractionation

“…Foam fractionation was performed to concentrate isoflavones from the soy whey wastewater under the suitable conditions of temperature 60°C, pH 5.0, volumetric air flow rate 80 mL/min and loading liquid height of 400 mm [9]. The enrichment ratio of isoflavones was 4.05.…”

“…Our previous work has indicated that isoflavones can be effectively concentrated from the soy whey wastewater using foam fractionation, in which whey soy proteins (WSP) are used as the collectors [9]. In order to obtain highly purified isoflavones, it is significant to isolate WSP from isoflavones in the foamate.…”

Cellulose citrate: a convenient and reusable bio-adsorbent for effective removal of methylene blue dye from artificially contaminated water

“…20,21 In spite of everything, methylene blue is surely one of the most used dye in textile industries and, for this reason, the developing of new strategies for the efficient removal from water effluents is still ongoing and of great interest. [22][23][24][25][26][27] The common methods for the removal of organic dyes include: chemical oxidation or reduction, 28 precipitation, 29 ion exchange, 30 electrolysis, 31 photo-catalytic processes, 32,33 membrane ltration, 34 ozonation, 35 degradation, 36 bio-sorption 37 and adsorption. 38,39 In particular, adsorption is one of the most used techniques because it relies on a simple mechanism, does not produce handling problems, and the process can be reversible.…”