Acetic acid recovery from a hybrid biological–hydrothermal treatment process of sewage sludge – a pilot plant study

2015 ◽  
Vol 71 (5) ◽  
pp. 734-739 ◽  
Author(s):  
J. Andrews ◽  
P. Dare ◽  
G. Estcourt ◽  
D. Gapes ◽  
R. Lei ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Sewage Sludge ◽  
Pilot Plant ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Biological Nutrient Removal ◽  
Wet Oxidation ◽  
Batch Mode ◽  
Oxidation Reactor

A two-stage process consisting of anaerobic fermentation followed by sub-critical wet oxidation was used to generate acetic acid from sewage sludge at pilot scale. Volatile fatty acids, dominated by propionic acid, were produced over 4–6 days in the 2,000 L fermentation reactor, which also achieved 31% solids reduction. Approximately 96% of the carbon was retained in solution over the fermentation stage. Using a 200 L wet oxidation reactor operating in batch mode, the second stage achieved 98% volatile suspended solids (VSS) destruction and 67% total chemical oxygen demand (tCOD) destruction. Acetic acid produced in this stage was recalcitrant to further degradation and was retained in solution. The gross yield from VSS was 16% for acetic acid and 21% for volatile fatty acids across the process, higher than reported yields for wet oxidation alone. The pilot plant results showed that 72% of the incoming phosphorus was retained in the solids, 94% of the nitrogen became concentrated in solution and 41% of the carbon was converted to a soluble state, in a more degradable form. Acetic acid produced from the process has the potential to be used to offset ethanol requirements in biological nutrient removal plants.

Production of propionic acid-enriched volatile fatty acids from co-fermentation liquid of sewage sludge and food waste using Propionibacterium acidipropionici

2013 ◽  
Vol 68 (9) ◽  
pp. 2061-2066 ◽  
Author(s):  
Xiang Li ◽  
Hui Mu ◽  
Yinguang Chen ◽  
Xiong Zheng ◽  
Jingyang Luo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Sewage Sludge ◽  
Propionic Acid ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Biological Nutrient Removal ◽  
Distribution Analysis ◽  
Propionibacterium Acidipropionici ◽  
Second Stage ◽  
Fermentation Liquid

Volatile fatty acids (VFA), derived from sludge fermentation, have been used as one effective carbon source for biological nutrient removal, especially favorable with VFA containing with high levels of propionic acid. In this paper, a new fermentation method was employed to significantly produce the propionic acid-enriched VFA from the co-fermentation liquid of sewage sludge and food waste: including (1) mixing food waste with sludge in the anaerobic digester (the first stage) and (2) separating the mixture, sterilizing the first stage liquid and fermenting it after inoculation with Propionibacterium acidipropionici (the second stage). The effect of the key parameters including pH, the mixing ratio of the food waste and sludge, fermentation time and temperature of the first stage on the propionic acid-enriched VFA production (the second stage) was individually discussed. By the molecular weight distribution analysis, the comparison of the solubilisation and hydrolysis process in difference parameters was fully elaborated. The optimal combination of the parameters was then obtained. Finally, the propionic acid-enriched VFA fermentation was successfully conducted in a semi-continuous reactor using the first stage liquid from the optimal condition.

Production of polyhydroxyalkanoate (PHA) by Ralstonia eutropha JMP 134 with volatile fatty acids from palm oil mill effluent as precursors

2015 ◽  
Vol 72 (11) ◽  
pp. 1889-1895 ◽  
Author(s):  
Tjandra Setiadi ◽  
Martha Aznury ◽  
Azis Trianto ◽  
Adi Pancoro
Keyword(s):  
Fatty Acids ◽  
Palm Oil ◽  
Volatile Fatty Acids ◽  
Ralstonia Eutropha ◽  
Anaerobic Fermentation ◽  
Palm Oil Mill Effluent ◽  
Fed Batch ◽  
Batch Mode ◽  
Pha Production ◽  
Palm Oil Mill

The highest volatile fatty acids (VFAs) concentration from palm oil mill effluent (POME) treated by anaerobic fermentation was achieved for a 1-day process when the main acids used were acetic, propionic and butyric acids. Polyhydroxyalkanoate (PHA) production with VFAs from POME as precursors in the fed-batch mode has advantages over batch mode, both in terms of its productivity and 3HV (3-hydroxyvalerate) composition in the produced polymer. With the fed batch, the productivity increased to 343% and contained more 3HV than those of the batch. The structures of the PHA were identified by different methods and they supported each other; the resulting products consisted of functional groups of 3HB (3-hydroxybutyrate) and 3HV.

Fermentation Properties of Waste Activated Sludge in an Enriched NO3--N System

2011 ◽  
Vol 281 ◽  
pp. 96-100
Author(s):  
Wei Tang ◽  
Yong Zhen Peng ◽  
Liang Chang Zhang ◽  
Shu Ying Wang
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Activated Sludge ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Waste Activated Sludge ◽  
Sludge Reduction ◽  
Late Period ◽  
Dominant Component ◽  
Anoxic Environment

In this research, NO3--N was added into the typical sludge anaerobic fermentation (TAF) of waste activated sludge (WAS), creating an anoxic environment for the growth of denitrifiers, as well as the inhibition of methanogens, therefore to insure the operation of simultaneous anoxic fermentation and denitrification (SAFD) system. Compared to TAF, SAFD can utilize the endogenous carbon source of WAS to denitrification, which achieved higher sludge reduction. Results showed that the SS, VSS in SAFD was reduced by 63.8% and 74.7%, respectively, which is obviously higher than that of 36.7% and 47.6% in TAF. Volatile fatty acids (VFAs) in TAF reached the top with propionic acid as dominant component in the mid-period of the fermentation; whereas that in SAFD was preferred by acetic acid in the late period. Evidenced by the variation of TN, NH4+-N and NO3--N, SAFD own a significant ability in denitrification, while the protein conversion appeared to be continuously low in this system.

Effect of pH on the Accumulation of Volatile Fatty Acids from Proteinaceous Excess Sludge

2013 ◽  
Vol 807-809 ◽  
pp. 472-477 ◽  
Author(s):  
Xiao Ling Liu ◽  
Jian Wang ◽  
Yong Hiu Song ◽  
Ping Zeng
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Soluble Proteins ◽  
Excess Sludge ◽  
Heating Method ◽  
Effect Of Ph ◽  
High Ph ◽  
Ph Values

Proteins were the primary organics of excess sludge. Their properties were related to pH, which in turn affected the production of volatile fatty acids (VFAs). Excess sludge was firstly pretreated using the thermo-alkaline method, and the centrifuged supernatant was then taken as the substrate to investigate the effect of pH on the accumulation of VFAs from proteinaceous waste. The heating method was used to treat the inoculums in order to inhibit the generation of bio-methane during the whole anaerobic fermentation. The results showed that pH had an obvious influence on the bioconversion of proteins. Although the conversion ratios were higher than 50% when pH was controlled at 7.0-11.0, the protein biodegradation was sensitive to too low or too high pH values. Soluble proteins were precipitated to become insoluble proteins with the adjustment of pH from alkaline to acid except at pH 3.0. Acetic acid was the main accumulated end-product at most of pH settings, and at pH 10.0, its concentration reached the maximum of 5.7 g·L-1 which was around 57.8% of total VFAs. At various pHs, it was soluble proteins that were responsible for VFAs production, while the precipitated proteins displayed a poor bio-degradability and disfavored the accumulation of VFAs during a 240 h of anaerobic fermentation.

scholarly journals Pilot Study of the Effects of Polyphenols from Chestnut Involucre on Methane Production, Volatile Fatty Acids, and Ammonia Concentration during In Vitro Rumen Fermentation

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Yichong Wang ◽  
Sijiong Yu ◽  
Yang Li ◽  
Shuang Zhang ◽  
Xiaolong Qi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Propionic Acid ◽  
Acid Content ◽  
Volatile Fatty Acids ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Quadratic Response ◽  
In Vitro Rumen Fermentation

Nutritional strategies can be employed to mitigate greenhouse emissions from ruminants. This article investigates the effects of polyphenols extracted from the involucres of Castanea mollissima Blume (PICB) on in vitro rumen fermentation. Three healthy Angus bulls (350 ± 50 kg), with permanent rumen fistula, were used as the donors of rumen fluids. A basic diet was supplemented with five doses of PICB (0%–0.5% dry matter (DM)), replicated thrice for each dose. Volatile fatty acids (VFAs), ammonia nitrogen concentration (NH3-N), and methane (CH4) yield were measured after 24 h of in vitro fermentation, and gas production was monitored for 96 h. The trial was carried out over three runs. The results showed that the addition of PICB significantly reduced NH3-N (p < 0.05) compared to control. The 0.1%–0.4% PICB significantly decreased acetic acid content (p < 0.05). Addition of 0.2% and 0.3% PICB significantly increased the propionic acid content (p < 0.05) and reduced the acetic acid/propionic acid ratio, CH4 content, and yield (p < 0.05). A highly significant quadratic response was shown, with increasing PICB levels for all the parameters abovementioned (p < 0.01). The increases in PICB concentration resulted in a highly significant linear and quadratic response by 96-h dynamic fermentation parameters (p < 0.01). Our results indicate that 0.2% PICB had the best effect on in-vitro rumen fermentation efficiency and reduced greenhouse gas production.

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