To Remove Phosphate from Municipal Wastewater with Insufficient Volatile Fatty Acids

2011 ◽  
Vol 356-360 ◽  
pp. 1769-1772
Author(s):  
Gong Fa Chang ◽  
Feng Zhang ◽  
Chang Qing Liu ◽  
Bo Zhang ◽  
Xue Jun Bi
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Volatile Fatty Acids ◽  
Municipal Wastewater ◽  
Phosphate Uptake ◽  
Plug Flow ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Flow Reactors ◽  
Phosphate Release

Tow plug flow reactors were operated with municipal wastewater according to reversed A2/O process. The only difference was in sludge return ratio. Despite that more VFAs were consumed by denitrification, phosphate removal was enhanced rather than impaired by a higher sludge return ratio of 300%. It seems that higher phosphate removal can be achieved even more nitrate was reduced which means more carbon source consumption. This is contradictory with the well accepted enhanced biological phosphate removal (EBPR) theory, which regards sufficient volatile fatty acids in the wastewater as the indispensable premise. With less phosphate was released in the anaerobic zones, the final phosphate concentration in the effluent was lower when higher sludge return ratio was applied. The results indicated that neither carbon source nor phosphate release can directly determine phosphate uptake ability.

scholarly journals Producing Omega-3 Polyunsaturated Fatty Acids: A Review of Sustainable Sources and Future Trends for the EPA and DHA Market

Resources ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 148
Author(s):  
Laura Oliver ◽  
Thomas Dietrich ◽  
Izaskun Marañón ◽  
Maria Carmen Villarán ◽  
Ramón J. Barrio
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Polyunsaturated Fatty Acids ◽  
Volatile Fatty Acids ◽  
Good Alternative ◽  
Future Market ◽  
Omega 3 ◽  
Alternative Pathways ◽  
Healthy Nutrition ◽  
Main Challenge

Omega-3 polyunsaturated fatty acids (Omega-3 PUFA) are recognized as being essential compounds for human nutrition and health. The human body generates only low levels of Omega-3 PUFA. Conventional sources of Omega-3 PUFA are from marine origin. However, the global growth of population combined with a better consumer understanding about healthy nutrition leads to the fact that traditional sources are exhausted and therefore not enough to satisfy the demand of Omega-3 PUFA for human diet as well as aquaculture. Microalgae cultivated under heterotrophic conditions is increasingly recognized as a suitable technology for the production of the Omega-3 PUFA. The high cost of using glucose as main carbon source for cultivation is the main challenge to establish economical feasible production processes. The latest relevant studies provide alternative pathways for Omega-3 PUFA production. As preliminary results show, volatile fatty acids (VFA) recovered from waste stream could be a good alternative to the use of glucose as carbon source in microalgae cultivation. The purpose of this paper is to highlight the actual situation of Omega-3 PUFA production, sources and market request to provide a summary on sustainable sources that are being investigated as well as present and future market trends in Omega-3 market.

A Mathematical Model of Volatile Fatty Acids (VFA) Production in a Plug-Flow Reactor Treating the Organic Fraction of Municipal Solid Waste (MSW)

1993 ◽  
Vol 27 (2) ◽  
pp. 201-208 ◽  
Author(s):  
E. D. Negri ◽  
J. Mata-Alvarez ◽  
C. Sans ◽  
F. Cecchi
Keyword(s):  
Mathematical Model ◽  
Fatty Acids ◽  
Municipal Solid Waste ◽  
Volatile Fatty Acids ◽  
Flow Reactor ◽  
Plug Flow ◽  
Biomass Concentration ◽  
Organic Fraction ◽  
Initial Biomass Concentration ◽  
Suspended Biomass

A mathematical model of a plug-flow reactor with a fluid recycle has been elaborated to simulate the VFA production process treating the organic fraction of the municipal solid waste. An alternative hydrolytic reaction model (homogeneous - heterogeneous) is proposed. The effect of a possible methanization step is also considered. The effect of process parameters (solid retention time (SRT), pH, recycle ratio) on the reactor performance is analyzed for parameters based on fruit and vegetable waste. The sensitivity of the model to proposed parameters (suspended biomass and initial biomass concentration) is also evaluated. It is found that the reactor production is very sensitive to the system pH. At low SRT, the production of volatile fatty acids (VFA) is proportional to this parameter. As the SRT increases methanization can reduce the VFA production. The effect of the recycle is negligible for the system and operating conditions studied. The effect of suspended biomass and initial biomass concentration was found to be also negligible. For the system analyzed, the pH is a critical parameter and a plug-flow arrangement (without recycle) seems to be the more reasonable election.

scholarly journals Pengaruh sumber karbon terhadap produksi bioplastik polihidroksialkanoat (PHA) dengan ralstonia eutropha

2018 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Martha Aznury ◽  
Tjandra Setiadi ◽  
Adi Pancoro
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Source ◽  
Fermentation Process ◽  
Volatile Fatty Acids ◽  
Ralstonia Eutropha ◽  
Operating Conditions ◽  
Batch Bioreactor ◽  
Pha Production ◽  
Fructose Fermentation

Bioplastic Polyhidroxyalknoate (PHA) is a polyester type bioplastic with physicochemical properties resemble to those of polypropilen from petroleum. PHA production was investigated to determine the effect of carbon source on the fermentation process by Ralstonia eutropha. Specifically, Ralstonia eutropha was cultivated in a batch bioreactor to show the dynamics of P(3HB-co-3HV) copolymer production from glucose or fructose as C source. In adition, the effect of volatile fatty acids addition, as stimulator to the copolymer production, was also studied. The operating conditions in a 7 L bioreactor were at temperature 30 oC and pH 7.0. The concentration of carbon source glucose or fructose was 40 g/L, and after 20 hour fermentation, volatile fatty acids were added. With volatile fatty acids addition, the resulting fructose fermentation had PHA content of 32.78%, in which the HV percentage was 11.78%. Meanwhile, the fermentation of glucose, stimulated by volatile fatty acids, gave PHA as much as 20.19% with HV percentage of 8.71%. Therefore,, the Ralstonia eutropha fermentation of fructose as the carbon source gave a higher yield than glucose. Keywords: Volatil Fatty Acid, Fructose, Glucose, PHA, P(3HB-co-3HV), Ralstonia eutropha AbstrakBioplastik polihidroksialkanoat (PHA) adalah bioplastik dari kelompok poliester dengan sifat fisikokimia mirip dengan plastik polipropilen dari minyak bumi. Penelitian ini bertujuan untuk mempelajari pengaruh sumber karbon terhadap poduksi PHA yang dilakukan dengan proses fermentasi menggunakan Ralstonia eutropha. Ralstonia eutropha dikultivasi dalam bioreaktor batch untuk mempelajari dinamika produksi kopolimer P(3HB-co-3HV) dari sumber karbon glukosa atau fruktosa, serta mempelajari pengaruh sumber stimulator asam lemak volatil. Kondisi operasional fermentasi menggunakan bioreaktor 7 L adalah pada temperatur 30 oC dan pH 7. Konsentrasi sumber karbon glukosa atau fruktosa yang digunakan adalah 40 gr/L, dan setelah 20 jam fermentasi ditambahkan asam lemak volatil yang berfungsi sebagai stimulator dalam produksi P(3HB-co-3HV). Panen sel Ralstonia eutropha dilakukan setelah 60 jam. Hasil penelitian menunjukkan fermentasi Ralstonia eutropha dengan substrat fruktosa dan asam lemak volatil sebagai stimulator mempunyai kandungan PHA sebesar 32,78%, dengan kadar HV 11,78%. Pada pemberian substrat glukosa dan asam lemak volatil menunjukkan kandungan PHA sebesar 20,19%, dengan kadar HV 8.71%. Jadi fermentasi Ralstonia eutropha dengan menggunakan substrat fruktosa memberikan yield yang lebih tinggi dibandingkan menggunakan substrat glukosa.Kata Kunci: Asam lemak volatil, fruktosa, glukosa, PHA, P(3HB-co-3HV), Ralstonia eutropha

scholarly journals Volatile Fatty Acids from Lipid-Extracted Yeast Provide Additional Feedstock for Microbial Lipid Production

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1009
Author(s):  
Gwon Woo Park ◽  
Seongsoo Son ◽  
Myounghoon Moon ◽  
Subin Sin ◽  
Kyoungseon Min ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Response Surface Methodology ◽  
Carbon Source ◽  
Response Surface ◽  
Volatile Fatty Acids ◽  
Lipid Production ◽  
Biodiesel Production ◽  
Microbial Lipid ◽  
Initial Ph ◽  
Microbial Lipid Production

Microbial lipid production from oleaginous yeasts is a promising process for the sustainable development of the microbial biodiesel industry. However, the feedstock cost poses an economic problem for the production of microbial biodiesel. After lipid extraction, yeast biomass can be used as an organic source for microbial biodiesel production. In this study, volatile fatty acids (VFAs), produced via anaerobic digestion of a lipid-extracted yeast (LEY) residue, were utilized as a carbon source for the yeast Cryptococcus curvatus. The response surface methodology was used to determine the initial pH and inoculum volume for the optimal VFA production. The experimental result for VFA concentration was 4.51 g/L at an initial pH of 9 and an inoculation 25%. The optimization results from the response surface methodology showed that the maximal VFA concentration was 4.58 g/L at an initial pH of 8.40 and an inoculation of 39.49%. This study indicates that VFAs from LEY can be used as a carbon source for microbial biodiesel production, with the potential to significantly reduce feedstock costs.

VOLATILE FATTY ACIDS FROM ORGANIC WASTES AS NOVEL LOW-COST CARBON SOURCE FOR Yarrowia lipolytica

2020 ◽  
Vol 56 ◽  
pp. 123-129 ◽  
Author(s):  
Mercedes Llamas ◽  
Elia Tomás-Pejó ◽  
Cristina González-Fernández
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Yarrowia Lipolytica ◽  
Volatile Fatty Acids ◽  
Low Cost ◽  
Organic Wastes

Improved Biological Phosphorus Removal Resulting from the Enrichment of Reactor Feed with Fermentation Products

1992 ◽  
Vol 26 (5-6) ◽  
pp. 943-953 ◽  
Author(s):  
L. H. Lötter ◽  
A. R. Pitman
Keyword(s):  
South Africa ◽  
Fatty Acids ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Volatile Fatty Acids ◽  
Phosphate Removal ◽  
Biodegradable Materials ◽  
Biological Phosphorus Removal ◽  
Fermentation Products ◽  
Biological Phosphorus

Research in South Africa has highlighted the dependence of biological phosphate removal mechanisms on the presence of certain minimum concentrations of some readily biodegradable materials including interalia volatile fatty acids. Successful generation of these compounds has been achieved at recently commissioned facilities at three of Johannesburg' activated sludge plants. Elutriation of the volatile fatty acids from the sludge was achieved by recycling sludge to the influent sewage stream. Significant improvements in phosphate removal were observed, thus reducing the demand for chemical dosing to achieve the phosphate standard. In this paper the effect of altering the feed sewage characteristics on biological phosphorus removal is discussed.

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