Modeling and Analysis of Biogas Generation Rate Sensitivity to Initial-pH, Leachate-Level and Ash-Loading during Anaerobic Biodegradation of Organic Solid Waste
William Wanasolo,
Samwel Manyele,
John Makunza
Issue:
Volume 2, Issue 3, May 2014
Pages:
21-27
Received:
10 May 2014
Accepted:
3 June 2014
Published:
20 June 2014
DOI:
10.11648/j.ajche.20140203.11
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Abstract: Anaerobic biodegradation of solid waste food-residues mixed with fruit-waste was carried out at mesophilic conditions. The goal was to model the sensitivity of biogas generation rate to initial-pH, leachate-level and ash-loading. Two process parameters were analyzed at centre-points while the third factor was set at low-, mid- and high-levels. The simulation results showed that at initial-pH of 5 (low-level), the biogas generation rate was more sensitive to ash-loading than at high-level of initial-pH values. The minimum and maximum attainable biogas generation rates due to perturbations in ash-loading were 0.79 and 1.89 mL/min, respectively, representing a difference of 1.10 mL/min. A comparison using sensitivity quotient revealed that decreasing leachate-level had a stronger effect on biogas generation rate than increasing it. It was also found that the biodegradation process was over four-times more sensitive to variations in initial-pH than in ash-loading while it was over seven-times more sensitive to variations in initial-pH than in leachate-level. It was concluded that the sensitivity of biogas generation rate was highest to variations in initial-pH and least to variations in leachate-level.
Abstract: Anaerobic biodegradation of solid waste food-residues mixed with fruit-waste was carried out at mesophilic conditions. The goal was to model the sensitivity of biogas generation rate to initial-pH, leachate-level and ash-loading. Two process parameters were analyzed at centre-points while the third factor was set at low-, mid- and high-levels. The ...
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Solid State Fermentation Process for Polygalacturonase Production Using Cashew Apple
Siumara R. Alcântara,
Flávio L. H. da Silva
Issue:
Volume 2, Issue 3, May 2014
Pages:
28-34
Received:
21 July 2014
Accepted:
30 July 2014
Published:
10 August 2014
DOI:
10.11648/j.ajche.20140203.12
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Abstract: The aim of this work was the optimization of solid state fermentation for polygalacturonases production using cashew apple dry bagasse as substrate and Aspergillus niger CCT0916. For this, it was observed the influence of moisture content, spore concentration, ammonium sulfate concentration and fermentation temperature on polygalacturonase activity. It was observed that moisture is the limiting factor in the process. Maximum polygalacturonase activity (33 U/g) was obtained with 50 %w.b initial moisture, 106 spores/g, 1.5 %(w/w) ammonium sulfate and temperature of 35°C. The models for 21, 29 and 54-hours of fermentation were statistically significant at 95% confidence level.
Abstract: The aim of this work was the optimization of solid state fermentation for polygalacturonases production using cashew apple dry bagasse as substrate and Aspergillus niger CCT0916. For this, it was observed the influence of moisture content, spore concentration, ammonium sulfate concentration and fermentation temperature on polygalacturonase activity...
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