Desalination of l-threonine (THR) fermentation broth by electrodialysis

Abstract

a b s t r a c tl-Threonine (THR) is widely used in the areas of pharmaceutical industry, medicine and food, which can be extracted from THR fermentation broth. The fermentation broth is pretreated by microfiltration and active carbon for decolorization, and then desalted by electrodialysis (ED) to remove salt ions such as Cl − , NH 4 + , Mg 2+ and Fe x+ . The ED performances are adjusted by the operation voltage, membrane type and initial feed pH, which are optimized to be 30 V, polyvinyl alcohol-based hybrid membranes and isoelectric point of 6.16, respectively. The end of desalination can be reached in the shortest time (106 min) when initial feed pH is at the isoelectric point. The highest THR recovery ratio is 86.1% with desalination ratio of 96.9%. The process energy consumption is 4.36 kW h/kg. Hence, the ED process is effective for desalination and recovery of THR. Removal of Cl − and NH 4 + (up to 99%) is the most effective, while Mg 2+ (87.3%) and Fe x+ (72.4%) are removed in lesser amount. Membrane fouling occurs after the ED process, which enhances the membrane area resistance from 1.8-2.1 to 2.5-2.7 Ω . cm 2 .

Concentration Dependencies of Diffusion Permeability of Anion-Exchange Membranes in Sodium Hydrogen Carbonate, Monosodium Phosphate, and Potassium Hydrogen Tartrate Solutions

“…The combination of biochemical and various membrane methods using electrodialysis (ED) for the final selective extraction and concentration of nutrients, in particular, phosphoric acid anions, leads to a significant cost reduction in fertilizer production, as well as to a decrease in sewage toxicity and volumes [1,4,5]. In addition, ED has shown its usefulness in the extraction of polyprotic carboxylic acids, which are the precursors in biodegradable polymer production, from the products of biochemical processing of biomass [6]; in tartrate stabilization of wine [7]; in peptide fractionation [8]; and in the demineralization of solutions containing amino acids, using, among others, phosphate buffers [9,10].…”

Desalination of Neutral Amino Acid Solutions in an Electromembrane System

“…Electrodialysis is considered a promising method for the demineralization of different multicomponent liquid media comprising AAs [ 40 , 41 , 42 , 43 ]. To perform the efficient ED demineralization of complex solutions, it is useful to study the electrochemical features of some model membrane systems containing AAs (zwitterlyte) along with a mineral salt (strong electrolyte).…”

Electro-membrane separations in biotechnology

“…Ion exchange and electrodialysis are the most spread treatment options in the downstream processing flow sheet [33]. There are several examples for aminoacid extraction from fermentation broth by electrodialysis in the recent years [34][35][36][37]. Those examples are for mono-sodium L-glutamate [34], methionine [35], L-phenylalanine [36] and L-threonine [37].…”