Investigation of acetone adsorption characteristics of activated carbons obtained from Zonguldak-Karadon coal at room temperature


Erdogan F. , Kopac T.

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.35, ss.2211-2224, 2020 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 35 Konu: 4
  • Basım Tarihi: 2020
  • Doi Numarası: 10.17341/gazimmfd.686415
  • Dergi Adı: JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY
  • Sayfa Sayıları: ss.2211-2224

Özet

Propionibacterium freudenreichii has been successfully applied to industrial anaerobic production of vitamin B-12. In the traditional fed-batch fermentation process, 5,6-dimethylbenzimidazole (DMB) is used as a precursor. However, DMB can inhibit the synthesis of vitamin B-12 metabolic intermediates, which is not conducive to semicontinuous fermentation of P. freudenreichii. To improve the fermentation efficiency, vitamin B-12 ex-situ biosynthesis was proposed and a membrane separation coupling fermentation technology was designed with adenosylcobinamide (Ado-cbi) as the indicator signal. The results showed that P. freudenreichii cells should be partly separated online at 84 h with 0.22-mu m spiral membrane. The fourfold concentrated suspension was suitable for ex-situ biosynthesis of vitamin B 12 with the addition of 3.60 mg L-1 DMB at 30 degrees C and pH 7.0. In the semi-continuous coupling fermentation process, vitamin B-12 concentration reached 56.76 +/- 3.86 mg L-1, an improvement of 161.6 %, while reutilizing fermentation wastewater and improving the anaerobic fermentation efficiency of P. freudenreichii.