PRODUCTION OF VOLATILE FATTY ACIDS AND ALCOHOLS FROM DAIRY WASTEWATER UNDER THERMOPHILIC CONDITIONS

2001 ◽  
Vol 44 (5) ◽  
Author(s):  
H. Q. Yu ◽  
H. H. P. Fang
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dairy Wastewater ◽  
Thermophilic Conditions ◽  
Fatty Acids And Alcohols

scholarly journals Acidogenesis of dairy wastewater at various pH levels

2002 ◽  
Vol 45 (10) ◽  
pp. 201-206 ◽  
Author(s):  
H.-Q. Yu ◽  
H.H.P. Fang
Keyword(s):  
Fatty Acids ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biomass Yield ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Alcohol Production ◽  
Mixed Liquor ◽  
Influence Of Ph ◽  
Fatty Acids And Alcohols

Continuous experiments were conducted to study the influence of pH in the range 4.0–6.5 on the acidification of dairy wastewater at 37°C with 12 hours of hydraulic retention in an upflow reactor. Results showed that degradation of dairy pollutants increased with pH from pH 4.0 to 5.5. At pH 5.5, 95% of carbohydrate, 82% of protein and 41% of lipid were degraded. Based on chemical oxygen demand (COD), 48.4% of dairy pollutants were converted into volatile fatty acids and alcohols in the mixed liquor, 6.1% into hydrogen and methane in biogas, and the remaining 4.9% into biomass. The biomass yield at pH 5.5 was estimated as 0.32 mg-VSS/mg-COD. Further increase of pH, up to 6.5, increased degradation of carbohydrate, protein and lipid only slightly, but resulted in the lowering of overall acid and alcohol production due to their increased conversion into methane. Acetate, propionate, butyrate and ethanol are the main products of acidogenesis. Productions of propionate and ethanol were favored at pH 4.0−4.5, whereas productions of acetate and butyrate were favored at pH 6.0−6.5.

scholarly journals Valorization of Glucose-Based Wastewater Through Production of Hydrogen, Volatile Fatty Acids and Alcohols

10.5772/67101 ◽  
2017 ◽  
Author(s):  
Eduardo Lucena Cavalcante de Amorim ◽  
Leandro Takano Sader ◽  
Lucas Rodrigues Ramos ◽  
Edson Luiz Silva
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Production Of Hydrogen ◽  
Fatty Acids And Alcohols

scholarly journals Limiting factors for anaerobic digestion of olive mill wastewater blends under mesophilic and thermophilic conditions

2018 ◽  
Vol 49 (2) ◽  
pp. 130-137
Author(s):  
Demetrio Antonio Zema ◽  
Giovanni Zappia ◽  
Souraya Benalia ◽  
Giuseppe Zimbalatti ◽  
Enzo Perri ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Olive Mill Wastewater ◽  
Limiting Factors ◽  
Citrus Peel ◽  
Thermophilic Conditions ◽  
High Concentrations ◽  
Olive Mill

Experimental trials of anaerobic digestion of olive mill wastewater (OMW) blended with other agro-industrial by-products were carried out to evaluate biogas production and sensitivity of the process to inhibiting compounds. Blends containing different percentages of OMW, digested liquid manure, and citrus peel were subjected to a batch anaerobic digestion process under both mesophilic and thermophilic conditions. The results showed that blends with percentages of OMW higher than 20% (v/v) had low methane yields due high concentrations of polyphenols (PPs) and/or volatile fatty acids (concentrations above 0.8 g kg–1 and 2.4 g L–1, respectively). The addition of other substrates such as citrus peel may have induced synergic inhibiting effects of PPs and essential oils (EO) on microbial growth. Thermophilic processes were more sensitive to these inhibiting compounds than mesophilic processes. The results of this study suggest that reducing PPs and EO concentrations in blends subject to anaerobic digestion below the inhibiting concentrations of 0.6 g L–1 and 0.5 g kg–1, respectively, is suitable. Additionally, it is advisable to maintain the volatile fatty acids content below 2 g L–1 to avoid its evident toxic effects on the growth of microorganisms in biochemical processes.

Volatile Fatty acids and Alcohols Production during Anaerobic Storage of Dairy Manure

2011 ◽  
Vol 54 (2) ◽  
pp. 599-607 ◽  
Author(s):  
H. M. El-Mashad ◽  
R. Zhang ◽  
V. Arteaga ◽  
T. Rumsey ◽  
F. M. Mitloehner
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dairy Manure ◽  
Anaerobic Storage ◽  
Fatty Acids And Alcohols

The effect of volatile fatty acids (VFAs) on nutrient removal in SBR with biomass adapted to dairy wastewater

2013 ◽  
Vol 48 (7) ◽  
pp. 809-816 ◽  
Author(s):  
Wojciech Janczukowicz ◽  
Joanna Rodziewicz ◽  
Kamila Czaplicka ◽  
Izabella Kłodowska ◽  
Artur Mielcarek
Keyword(s):  
Fatty Acids ◽  
Nutrient Removal ◽  
Volatile Fatty Acids ◽  
Dairy Wastewater

Impact of volatile fatty acids to alkalinity ratio and volatile solids on biogas production under thermophilic conditions

2020 ◽  
pp. 0734242X2095739
Author(s):  
Abdul-Aziz Issah ◽  
Telesphore Kabera
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Total Alkalinity ◽  
Stable Range ◽  
Start Up ◽  
Volatile Solids ◽  
Significant Difference ◽  
Thermophilic Conditions ◽  
The Impact

The study assessed the impact of volatile fatty acids (VFA) to total alkalinity (TA) ratio (VFA/TA), and percentage volatile solids (VS) reduction of batch and semi-continuous anaerobic co-digestion of palm nut paste waste (PNPW) and anaerobic-digested rumen waste (ADRW) on digester stability and biogas production under the environmental condition of 50 ± 1°C and hydraulic retention time of 21 days for the batch studies and 14 days for semi-continuous co-digestion. The co-digestion ratios were based on percentage digester volume corresponding to 90%:10%, 75%:25% and 50%:50%. During batch and semi-continuous anaerobic co-digestion, VFA/TA of 0.32–1.0 and VS reduction of 53–67% were observed as the stable range at which biogas production was maximum. In terms of semi-continuous anaerobic digestion (AD), except for the 50%:50% ratio where biogas production progressed steadily from the first to fourteenth days, biogas production initially dropped from 180.1 to 171.3 mL between the first and third days of the 90%:10% reaching a maximum of 184 mL on the fourteenth day. Biogas production declined from 198.8 to 187.5 mL on the second day and then increased to 198.8 ± 0.5 mL in the case of the 75%:25% with a significant difference between the treatment ratios at p < 0.05. Therefore, the study can confirm that the 50%:50% ratio (PNPW:ADRW) is a suitable option for managing crude fat-based waste under thermophilic AD due to its potential for rapid start-up and complete biodegradation of active biomass within a 21-day period. This presupposes that residual methane as greenhouse gas will be void in the effluent if disposed of.

Generation and Emissions of Volatile Fatty Acids and Alcohols during Anaerobic Storage of Dairy Manure

2010 ◽  
Author(s):  
Hamed M El-Mashad ◽  
Ruihong Zhang ◽  
Veronica Arteaga ◽  
Tom R Rumsey ◽  
Frank M Mitloehner
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dairy Manure ◽  
Anaerobic Storage ◽  
Fatty Acids And Alcohols

Generation and Utilization of Volatile Fatty Acids and Alcohols in Hydrothermally Altered Sediments in the Guaymas Basin, Gulf of California

2019 ◽  
Vol 46 (5) ◽  
pp. 2637-2646 ◽  
Author(s):  
Guang‐Chao Zhuang ◽  
Andrew Montgomery ◽  
Vladimir A. Samarkin ◽  
Min Song ◽  
Jiarui Liu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gulf Of California ◽  
Volatile Fatty Acids ◽  
Guaymas Basin ◽  
Fatty Acids And Alcohols

Granulation and sludge retainment during start-up of a thermophilic UASB reactor

1998 ◽  
Vol 38 (8-9) ◽  
pp. 349-357 ◽  
Author(s):  
Kazuaki Syutsubo ◽  
Hideki Harada ◽  
Akiyoshi Ohashi
Keyword(s):  
Fatty Acids ◽  
Sewage Sludge ◽  
Retention Time ◽  
Volatile Fatty Acids ◽  
Synthetic Wastewater ◽  
Uasb Reactor ◽  
Start Up ◽  
Thermophilic Conditions ◽  
Digested Sewage Sludge ◽  
Granulation Mechanism

A laboratory-scale UASB reactor was operated at 55°C over 600 days in order to investigate the granulation mechanism under thermophilic conditions. The reactor was seeded with a thermophilic digested sewage sludge, and fed with a synthetic wastewater composed of sucrose and volatile fatty acids. As a result of establishment of the whole granulated sludge bed, the reactor allowed ultimately a volumetric COD loading of 45 kgCOD m−3 d−1 with 90% COD removal. The maximum sludge loading achieved was 3.7 gCOD·gVSS−1 d−1, that is two to three times as large as that of mesophilically grown sludge. The behavior of SRT (sludge retention time) was closely correlated with the biogas evolution flux: excessive biogas evolution at the highest COD loading (45 kgCOD m−3 d−1) enhanced the sludge washout, and thus led to shortening of SRT into less than 7 days. Methanogenic activities of the retained sludge increased finally up to 110 times for acetate, 25 times for propionate, and 3.6 times for hydrogen as large as those of the seeded sludge.

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