Soy Research Today is a free monthly online journal that collates and summarizes the latest research about Soy, including details on soy milk, soy protein, soya bean, benefits, dangers.

Improving acidogenic performance in anaerobic degradation of solid organic waste using a rotational drum fermentation system.

Jiang WZ, Kitamura Y, Li B

College of Water Conservancy & Civil Engineering, China Agricultural University, Beijing 100083, China. jiangwz@cau.edu.cn

The effects of leachate from a methanogenic process on acidogenic performance of a solid recycle (SR) process by a rotational drum fermentation (RDF) system were evaluated under mesophilic condition and a hydraulic retention time (HRT) of 20 days. Two SR process configurations, SR1 and SR2, were evaluated, using fresh soybean meal or Okara as substrates. An apparent first-order hydrolysis rate constant of 5.0 x 10(-3)/d for SR1 at pH values of 4.4 and 14.4 x 10(-3)/d for SR2 at pH of 5.0, were obtained. The apparent volatile solids (VS) degradation ratio ranged from 9.6% to 19.4% and total volatile acid (as acetic acid) from 10.8 to 14.9 g/L. Occupying ratios for ionized volatile acid (VA) increased from 30.6% to 63.4% after recycling the leachate to process. However, occupying ratios of acetic acid decreased from 93.3% to 42.0% whereas propionic acid and butyric acid ratios increased in SR2. Integrating the VA production with the hydrolysis rate constants, it is clear that the recirculation of leachate considerably enhanced acidogenic performance of solid recycle process.

Published 27 June 2005 in Bioresour Technol, 96(14): 1537-43.
Full-text of this article is available online (may require subscription).

© 2004-2008 Soy Research Today. All Rights Reserved.