Optimization of Extraction Lactic Acid from Fermented Broth by Fixed-bed Adsorption

Pretreated lactic acid fermentation broth has been screened on the adsorption and desorption capacities through five kinds of resin,anionic exchange resin D301G was chosen to adsorb lactic acid from the fermentation broth.By studying the single-stage process,the optimum operation condition as follows:3 hours,pH 3,fermentation broth concentration 86.0 g/L.Under the optimum conditions,the ion exchange capacity reaches 237 mg/g which were based on the orthogonal test optimization.Some factors of fixed-bed adsorption process such as speed of flow,height-diameter ratio were systematically examined.Finally,the optimum operation condition:1 mL/min and height-diameter ratio 10.8:1.Under the optimum conditions,the ion exchange capacity can reach 193 mg/g with the penetration time 60 min which were found by drawing the breakthrough curve.