Biohydrogen production from ruminal contents

Abstract

Hydrogen gas is a promising alternative for fossil fuel at the current time due to the advantages that is environment friendly, it can be derived from renewable sources and it has high energy efficiency. In the present study, hydrogen gas was producedin a biological way by using rumen fluid of cattle collected from slaughter house by dark fermentation of rumen fluid and Microbial Electrolysis Cell (MEC) process. Integration of both dark fermentation and MEC was also carried out.The Microbial electrolysis cell (MEC) was designed and made for the biohydrogen production. The parameters such as pH, salt-bridge, catholyte, electrodes and substrates were optimized for the production of biohydrogen. Among the pH 4, 5, 6, 7 and 8, the highest amount of biohydrogen production was obtained in pH 6. 0.8% and 1% of agarose and agar-agar were used as salt-bridge in the MEC and the highest biohydrogen production was obtained in MEC with 0.8% agarose. The electrodes used were carbons rods and graphite plates where the MEC with graphite plates as the electrode showed higher biohydrogen production. Sodium chloride in different concentrations such as 0.25M, 0.5M, 0.75M and 1M were used and it was found that 0.5M Sodium chloride produced highest amount of biohydrogen in MEC. The substrates added to the rumen fluid in the anode chamber were 1% rice bran, 1% powdered potato peel and 1% powdered tapioca peel and the highest amount of biohydrogen production was obtained in the MEC with 1% rice bran.The integration of dark fermentation and MEC was carried out for an enhanced amount of biohydrogen production. The total amount of biohydrogen produced was calculated from the individual amount of biohydrogen produced by dark fermentation and MEC. The quantity of biohydrogenproduced were statistically analysed and the obtained p value is less than 0.005 (pand#8804;0.005) which shows that the quantity of biohydrogen produced with different pH and substrates were statistically significant. newline newline