Effect of pH, temperature and agitation on thermophilic biohydrogen production using immobilized cells on carbon composites (GAC-NiFe3O4)

• Published in: CHEMICAL ENGINEERING JOURNAL
• Main Authors: Jamaludin, Nina Farhana Mohd; Engliman, Nurul Sakinah; Manaf, Shareena Fairuz Abdul; Idrus, Syazwani; Abdullah, Luqman Chuah; Jamali, Nur Syakina
• Format: Article
• Language: English
• Published: ELSEVIER SCIENCE SA 2024
• Subjects: Engineering
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001202595700001
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2024.149980

Carbon composites-immobilized cell was utilized to enhance biohydrogen production. The initial pH, temperature and agitation effect was studied using the one-factor-at-a-time (OFAT) method. The optimal initial pH obtained was at pH 6.0 with hydrogen yield (HY) of 2.66 +/- 0.09 mol H-2/mol sugar, correlating with Gompertz constant of H-m = 974.99 mL, R-m = 17.90 mL/h and lambda = 1.70 h. At 60 degrees C, the highest HY was obtained at 2.75 +/- 0.11 mol H-2/mol sugar. These corresponded to the Gompertz constant of H-m = 934.58 mL, R-m = 18.78 mL/h and lambda = 1.89 h. The optimal agitation obtained was at 120 rpm, attaining the highest HY of 3.44 +/- 0.54 mol H-2/mol sugar, corresponding to the Gompertz constant of H-m = 1054.86 mL, R-m = 24.37 mL/h and lambda = 3.90 h. The rRNA sequencing result revealed that the predominant species in the study was Thermoanaerobacterium. This study provides critical insight into process control conditions on biohydrogen production.