High-rate anaerobic hydrolysis and acidogenesis of sewage sludge in a modified upflow reactor

Yu, Han‐Qing; Zheng, Xucai; Hu, Zhenhu; Gu, G.

doi:10.2166/wst.2003.0224

Cited by 63 publications

(25 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The suitable nutrients, expressed as C : N ratio, in fermentation substrates were therefore necessary for acidogenic bacteria to produce SCFAs efficiently. It was also reported that the accumulation of SCFAs during organic wastes acidification was affected by pH, but the relative information was obtained in the case of pH less than 7.0 [7,14]. It was observed in our study that pH was a key parameter which influenced the hydrolysis and acidification of fermentation substrate in the range of pH 4.0-11.0.…”

Section: Introductionmentioning

confidence: 49%

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Feng

Yan

Chen

2011

Front. Environ. Sci. Eng. China

View full text Add to dashboard Cite

Effect of pH ranging from 4.0 to 11.0 on cofermentation of waste activated sludge (WAS) with food waste for short-chain fatty acids (SCFAs) production at ambient temperature was investigated in this study. Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system, which resulted in the increases of SCFAs production and substrate reduction. The SCFAs production at pH 6.0, 7.0, 8.0, and 9.0 and fermentation time of 4 d was respectively 5022.7, 6540.5, 8236.6, and 7911.7 mg COD$L -1 , whereas in the blank tests (no pH adjustment, pH 8.0 (blank test 1), no food waste addition, pH 8.0 (blank test 2), and no WAS addition (blank test 3)) it was only 1006.9, 971.1, and 1468.5 mg COD$L -1 , respectively. The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA, which was followed by acetic and n-butyric acids, while acetic acid was the top product under other conditions. At pH 8.0 a higher volatile suspended solids (VSS) reduction of 16.6% for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste. The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions. The release of NH þ 4 -N increased with fermentation time at all pH values investigated except 4.0, 5.0 and in blank test one. The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs. Ammonia and phosphorus need to be removed before the SCFAsenriched fermentation liquid from WAS and food waste was used as the carbon source.

show abstract

Section: Introductionmentioning

confidence: 49%

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Feng

Yan

Chen

2011

Front. Environ. Sci. Eng. China

View full text Add to dashboard Cite

show abstract

“…Total solids degradation was 41% of TVS. This is considered low compared to volatile solid destruction of 43.8-72.5% and 34-78% achieved by Elefsiniotis and Oldham (1994) and Yu et al (2003), respectively. These studies, however, used sewage sludge where biodegradability and surface area would be different from OFMSW used in our study.…”

Section: Lab-scale Batch Thermophilic Anaerobic Digestion Of Pre-aeramentioning

confidence: 75%

Effect of pre-aeration and inoculum on the start-up of batch thermophilic anaerobic digestion of municipal solid waste

Charles

Walker

Cord‐Ruwisch

2009

Bioresource Technology

149

View full text Add to dashboard Cite

In this study, a short pre-aeration step was investigated as pre-treatment for thermophilic anaerobic digestion of the organic fraction of municipal solid waste (OFMSW). It was found that pre-aeration of 48 hours generated enough biological heat to increase the temperature of bulk OFMSW to 60 o C. This was sufficient selfheating of the bulk OFMSW for the start-up of thermophilic anaerobic digestion without the need for an external heat source. Pre-aeration also reduced excess easily degradable organic compounds in OFMSW, which were the common cause of acidification during the start-up of the batch system. Careful consideration however must be taken to avoid over aeration as this consumes substrate, which would otherwise be available to methanogens to produce biogas. To accelerate methane production and volatile solids destruction, the anaerobic digestion in this study was operated as a wet process with the anaerobic liquid recycled through the OFMSW.Appropriate anaerobic liquid inoculum was found to be particularly beneficial. It provided high buffer capacity as well as suitable microbial inoculum. As a result, acidification during start-up was kept to a minimum. With volatile fatty acids (VFAsacetate in particular) and H 2 accumulation typical of hydrolysis and fermentation of the easily degradable substrates during start-up, inoculum with high numbers of hydrogenotrophic methanogens was critical to not only maximise CH 4 production but also reduce H 2 partial pressure in the system to allow VFAs degradation. In a lab scale bioreactor, the combined pre-aeration and wet thermophilic anaerobic digestion was able to stabilise the OFMSW within a period of only 12 days. The stabilised inert residual material can be used as a soil amendment product.3 of 32

show abstract

“…The experiments were carried out in 1000 mL conical flasks and the working volume was 500 mL. According to the reported results, 26,27 an acidic or near neutral pH condition is advantageous to VFAs production in the anaerobic digestion of sludge. Therefore, the initial pH of all samples was adjusted to 6.0 using 2 mol L −1 hydrochloric acid.…”

Section: Batch Fermentation Testsmentioning

confidence: 99%

Effects of organic matter and initial carbon–nitrogen ratio on the bioconversion of volatile fatty acids from sewage sludge

Liu

Chen

et al. 2008

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

High-rate anaerobic hydrolysis and acidogenesis of sewage sludge in a modified upflow reactor

Cited by 63 publications

References 12 publications

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Effect of pre-aeration and inoculum on the start-up of batch thermophilic anaerobic digestion of municipal solid waste

Effects of organic matter and initial carbon–nitrogen ratio on the bioconversion of volatile fatty acids from sewage sludge

Contact Info

Product

Resources

About