Valorization of Cheese Whey by Electrohydrolysis for Hydrogen Gas Production and COD Removal

Kargi F., Uzuncar S.

WASTE AND BIOMASS VALORIZATION, vol.4, no.3, pp.517-528, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 4 Issue: 3
  • Publication Date: 2013
  • Doi Number: 10.1007/s12649-012-9188-5
  • Journal Name: WASTE AND BIOMASS VALORIZATION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.517-528
  • Keywords: Cheese whey, COD content, Electrohydrolysis, Hydrogen gas, Valorization, FATTY-ACID VFA, WASTE-WATER, BIOHYDROGEN PRODUCTION, POWDER SOLUTION, ETHANOL FERMENTATION, PHOTO-FERMENTATION, DARK, ELECTROLYSIS, ORGANICS
  • Dokuz Eylül University Affiliated: Yes

Abstract

Diluted cheese whey (CW) solutions with different initial COD contents (4,800-25,000 mg l(-1)) were electro-hydrolyzed by application of constant DC voltage (3 V) for hydrogen gas production and COD removal. The highest cumulative hydrogen production (3,923 ml), hydrogen yield (1,719 ml H-2 g(-1) COD), hydrogen formation rate (699 ml d(-1)), and percent hydrogen (99.2 %) in the gas phase were obtained with the highest initial COD of 25,025 g COD l(-1) with an energy conversion efficiency of 90.3 %. Hydrogen gas production in water and cheese whey controls were negligible indicating no significant H-2 gas production by electrolysis of water and fermentation of cheese whey. Percent COD removals were between 18 and 20 % for initial CODs above 11,500 mg l(-1). Major COD removal mechanism was anaerobic fermentation of carbohydrates producing volatile fatty acids (VFA) and CO2. Hydrogen gas was produced by reaction of (H+) ions released from VFAs and electrons provided by DC current. Electro-hydrolysis of CW solution was proven to be an effective method of H-2 gas production with simultaneous COD removal.