Performance analysis of immobilized and co-immobilized enriched-mixed culture for hydrogen production

Abstract

This paper presents an experimental investigation on using mixed culture for immobilization and co-immobilization for hydrogen production. The shape and diameter of the beads were investigated. Hydrogen was produced from 10 g.L-1 glucose in anaerobic batch using immobilized mixed culture with extrusion dripping method. The alginate concentrations as immobilization material were 1%, 2%, and 3%. The mixed culture had three different biodigester sources consisting of cow dung, tofu waste, and fruit waste. The pretreatment of each mixed culture was acidification and enrichment. Then the mixed culture were mixed with immobilization material and inserted into a syringe, then dropped into 0.1M CaCl2. Activated carbon was added to alginate (coimmobilization) with ratio 1:1. The results showed that bead using 1% and 2% alginate concentrations were a pear-shaped. The highest concentration of hydrogen (mol H2/mol glucose) was 0.029 for immobilized beads with 2% alginate concentration and the lowest hydrogen (molH2/mol glucose) was 0.009 for immobilized beads with 3% alginate concentration. Acetic acid was the most dominant. The highest VFA (mg.L-1) was 695.85 for immobilized beads with 3% alginate concentration (acetic acid 271.49; propionic acid 163.33; isobutyrate acid 123.45; butyric acid 137.57). Most hydrogen was produced from 2% alginate concentration and spherical-shape.

Keywords

• immobilization
• mixed culture
• alginate
• activated carbon
• beads
• hydrogen