两级泡沫分离废水中大豆蛋白的工艺

Technology of soy protein separation from wastewater by two-stage foam fractionation

为了有效处理高浓度大豆蛋白废水,在研究初始pH值、表观气速和温度特别是在较高温度(60℃)对泡沫分离大豆蛋白废水效果影响的基础上,建立了可同时提高富集比和回收率的两级泡沫分离工艺。在60℃时,对大豆蛋白质量浓度为4.0g/L的废水泡沫分离,富集比比常温时提高4倍多。两级泡沫分离工艺中,第一级分离在大豆蛋白质量浓度为4.0g/L,初始pH值为7.0,表观气速0.133cm/s,60℃下操作,富集比为7.71,残液作为第二级泡沫分离的进料;第二级分离先在20℃,表观气速0.133cm/s下进行,待塔顶无泡沫溢出时,再将表观气速升到0.398cm/s,富集比为2.63,消泡液加入到废液中作为第一级泡沫分离的进料;总回收率为82.75%。在不同温度和气速下进行的两级泡沫分离工艺可以有效的处理大豆蛋白废水,回收其中的蛋白质。

In order to deal with wastewater with high soy protein effectively,a technology of two-stage foam fractionation,which could increase both enrichment ratio and recovery of soy protein,was developed based on the research of the influences of initial pH value,superficial air flow rate and temperature,specially at higher temperature（60℃） on foam fractionation. When soy protein concentration of the wastewater was 4.0 g/L,enrichment ratio at 60℃ was four times higher than that at the normal temperature. When the conditions of the first stage of the two-stage foam fractionation were soy protein concentration of the wastewater as 4.0 g/L,initial pH value of the wastewater as 7.0,superficial air flow rate as 0.133 cm/s and temperature as 60℃,enrichment ratio of soy protein was 7.71,and the residual solution was fed to the second stage as the feed stream. The second stage run at 20℃ and 0.133 cm/s for superficial air flow rate,firstly,when no foam stream overflowed from the top of foam fractionation tower,superficial air flow rate was increased to 0.398 cm/s,and enrichment ratio of soy protein reached 2.63,and then the foamate was added to the wastewater as the feed stream of the first stage. The total recovery of the two-stage foam fractionation was 82.75%. Two-stage foam fractionation at different temperatures and superficial air flow rates can be used efficiently for the wastewater treatment and soy protein recovery.