Abstract:

Anionic exchange resins D301G and D311 were chosen to adsorb lactic acid from the fermentation broth, and some factors such as time, fermentation broth concentration, temperature, speed, pH value, flow rate and filling amount of resin were systematically examined. By investigating the single-stage process, the optimum operation conditions were obtained as follows: 3 h, pH 3 and fermentation broth concentration 86.0 g/L. Under the above conditions, the ion exchange capacity can reach 237 mg/g. Moreover, adsorption kinetics and thermodynamics of lactic acid by special resin were also investigated. Results indicated that the adsorption isotherm corresponds with Fiendish equation Qc=KC1/n and its kinetic equation is Qt=Q0+aet/b.

Key words: lactic acid, weak anion resin, adsorption, desorption, adsorption isotherm, adsorption kinetics