A pH- and temperature-phased two-stage process for hydrogen and methane production from food waste

Effect of fermentation liquid from food waste as a carbon source for enhancing denitrification in wastewater treatment

“…Recently, some literature have evaluated the effects of pH, temperature, substrate concentration, hydraulic retention time (HRT) and organic loading rate (OLR) on the hydrolysis and acidification of food waste (Kim et al, 2006;Chu et al, 2008;Nagao et al, 2012;Jiang et al, 2013). Most previous research has focused on the effects of the aforementioned factors on VFAs production from food waste and then selected the operational parameters that produced the maximum VFAs, all of which were based on the adjusted pH values in the above-mentioned research.…”

“…Most previous research has focused on the effects of the aforementioned factors on VFAs production from food waste and then selected the operational parameters that produced the maximum VFAs, all of which were based on the adjusted pH values in the above-mentioned research. However, so far the fermentation products, as external carbon source have failed to gain practical application in WWTPs due to the specific drawbacks of time consuming (5e10 days), consumption of large amount of chemicals (especially for pH adjustment), and particularly larger degree degradation of organic substrates (more than 50%) in the form of gas release (Chu et al, 2008;Liu et al, 2013b;Jiang et al, 2013). In fact, by free hydrolysis and acidogenesis, which usually takes short time and retains most of organics, the carbohydrate and protein of food waste can be transformed to intermediates readily or slowly utilizable by bacteria in the biological reactors (Elefsiniotis et al, 2004), though they are not really in the form of VFAs or lactic acid that are commonly recognized as high quality carbon sources for denitrification (Elefsiniotis and Li.…”

Biohydrogen production from food waste in batch and semi-continuous conditions: Evaluation of a two-phase approach with digestate recirculation for pH control

“…This affects the HRT, which typically ranges from 2 to 5 days in a continuous or semi-continuous fed system. Twophase approaches using FW as substrate without recirculation have been tested over a wide range of organic loadings [14,15,16,17,18,19], and in general showed a specific hydrogen production (SHP) below 71 m 3 H 2 kg -1 VS. Only a few studies have used a two phase approach with recirculation of the AD effluent [11,14,16,20].…”

Ethanol and Hydrogen Production with Thermophilic Bactera from Sugars and Complex Biomass

“…Recent study of H 2 production from kitchen waste with mixed cultures from various sources showed good production rates (66.7 ml L -1 h -1 ) but much lower yields (0.23 mol H 2 mol glucose -1 equivalent) . A continuous culture study on H 2 production from food waste by the use of mixed culture originating from anaerobic waste water treatment plant resulted in maximum of 2.8 mol H 2 mol hexose -1 (Chu et al, 2008). Other studies with food waste include e.g.…”