Rapid generation of volatile fatty acids (VFA) through anaerobic acidification of livestock organic waste at low hydraulic residence time (HRT)

Volatile fatty acids (VFAs) are proposed platform molecules for the production of basic chemicals and polymers from organic waste streams. A simple bio-reactor was fabricated with locally available materials to conduct this study. A lab-scale anaerobic batch reactor was fed with potato waste and banana waste as substrate to find out the potential organic waste that has maximum VFAs production capacity. Between these two wastes, banana waste was found better for VFAs production. The product spectrum remained similar at the pH range 4.0-4.5 but higher pH reduced the VFAs production. The operation of anaerobic digestion with uncontrolled pH reduced the pH 4.0 to 4.5. Therefore, it is better to run the anaerobic digestion without controlling the pH while aiming to VFAs production. A small amount nutrient (ammonium nitrogen) significantly increases the VFAs production but higher amount nutrient has an inhibition effect. However commercial surfactant has a strong inhibition effect on VFAs producing organism and hence reduced the VFAs production. The efficient production of VFA at uncontrolled pH with a small amount of ammonium nitrogen increases the economic feasibility of organic waste-based VFAs production.

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Fungal Purification of an Industrial Effluent Containing Volatile Fatty Acids by Means of a Crossflow-Microscreen Technique

Water Science & Technology ◽

10.2166/wst.1989.0225 ◽

1989 ◽

Vol 21 (4-5) ◽

pp. 221-229 ◽

Cited By ~ 4

Author(s):

A. L. Kühn ◽

W. A. Pretorius

Keyword(s):

Residence Time ◽

Volatile Fatty Acids ◽

Industrial Effluent ◽

Industrial Effluents ◽

Geotrichum Candidum ◽

Hydraulic Residence Time ◽

Monocarboxylic Acids ◽

A Cell ◽

Recycle Reactor ◽

Selective Mechanism

An industrial effluent containing C2 to C5 monocarboxylic acids was successfully treated by the fungus Geotrichum candidum using the selective mechanism of the crossflow-microscreen method. Due to the cell separating capacity of the microscreen the system could be operated as a cell recycle reactor with the hydraulic residence time (θ) independent of the mean cell residence time (θx). At θ = 1.25 h and θx = 7.5 h, 89.5% COD reduction was obtained. The excess biomass could be harvested by simple screening and contained a crude protein content of 50.2%, which may be used as a feed supplement. The growth kinetic values obtained for a monoculture of G. candidum grown on the industrial effluenf were as follows: µmax = 0.26 h−1, Y = 0.38 g cells g−1 COD, Ks = 201 mg COD ℓ−1, kd = .009 h−1, indicating the potential use of this micro-organism for the treatment of several industrial effluents.

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Development of headspace–gas chromatography–flame ionization detection procedure to determine volatile fatty acids in zoo organic waste leachates

Water Science & Technology ◽

10.2166/wst.2011.516 ◽

2011 ◽

Vol 63 (12) ◽

pp. 2873-2877 ◽

Cited By ~ 2

Author(s):

Anna Banel ◽

Marta Wasielewska ◽

Monika Felchner-Żwirełło ◽

Bogdan Zygmunt

Keyword(s):

Fatty Acids ◽

Gas Chromatography ◽

Organic Waste ◽

Volatile Fatty Acids ◽

Sample Introduction ◽

Flame Ionization Detection ◽

Monocarboxylic Acids ◽

Ionization Detection ◽

Flame Ionization ◽

Headspace Gas

In order to determine volatile fatty acids (short chain monocarboxylic acids with 2 to 6 carbon atoms in a molecule) in leachates formed in organic waste piles a procedure based on static headspace (HS) coupled with gas chromatography (GC) have been proposed and optimized. The conditions of HS extraction and sample introduction into a gas chromatograph as well as of chromatographic separation were considered. Using flame ionization detection LODs were of the order of 0.02– 0.37 mg/L. The analyzed leachate collecting on and close to a zoo organic waste pile contained VFAs (Volatile Fatty Acids) at a concentration ranging from 5.5 mg/L to 0.88 g/L and from below LOD to 10.1 mg/L for pool water at some distance from the pile, respectively.

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Effects of sludge age on anaerobic acidification of waste activated sludge: Volatile fatty acids production and phosphorus release

Journal of Environmental Sciences ◽

10.1016/j.jes.2020.12.030 ◽

2021 ◽

Vol 105 ◽

pp. 11-21

Author(s):

Sisi Chen ◽

Xiaohu Dai ◽

Dianhai Yang ◽

Bin Dong

Keyword(s):

Fatty Acids ◽

Activated Sludge ◽

Volatile Fatty Acids ◽

Phosphorus Release ◽

Waste Activated Sludge ◽

Anaerobic Acidification

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Physiology and Rumen Microbial Ecology of Goats Fed Municipal Organic Solid Wastes Treated with Diastic Microbes from Snail (Achatina achatina)

Annual Research & Review in Biology ◽

10.9734/arrb/2021/v36i1030438 ◽

2021 ◽

pp. 82-94

Author(s):

Agida, Christopher Agboje ◽

Essien Ekpenyong Nsa ◽

Uduakobong Essien John ◽

Constance Ihuoma Adje ◽

A. N. Chukwuemela ◽

...

Keyword(s):

Fatty Acids ◽

Microbial Ecology ◽

Solid Waste ◽

Organic Waste ◽

Volatile Fatty Acids ◽

Panicum Maximum ◽

Total Volatile ◽

Organic Solid Waste ◽

Organic Solid ◽

Municipal Organic Solid Waste

The experiment was conducted with the objective of providing more information on the physiology and rumen microbial ecology of goats fed municipal organic solid waste treated with Diastic microbes of snails (Achatina achatina). The study was on the treated and untreated municipal organic solid waste as components of experimental diet. Balanced rations containing diets; A = 45% untreated municipal organic waste (UMOW), B = 45% treated municipal organic waste (TMOW), and C = 70% treated municipal organic waste (TMOW), with wheat offal, palm kernel cake, and molasses used to balance the diets. Where grass/legume ratio of 3 parts of Panicum maximum and 1 part of Centrocema were fed across treatments at the same proportion. The three rations were fed to 18 unsex Red Sokoto goats aged between 6 to 7 months, with an average weight of 8.01±2.50kg. They were housed in pens, on a floor space of 0.5 to 0.75m2 in a completely randomized designed experiment replicated six times and fed for a period of 52 days. The results were separated according to the parameters of rumen physiology (pH, total volatile fatty acids, acetic, propionic, butyric acids and ethanol, and rumen ecology (bacteria, protozoa, and fungi, which are mainly anaerobic microbes). The investigations revealed that microbial (bacteria, protozoa and fungi) load counts were significantly (p<0.05) influenced by dietary treatments. While the total volatile fatty acids (TVFA), acetic, butyric and propionic increased (p<0.05) except for the TVFA and the propionic acid that showed numerical (p>0.05) increased levels of (TMOW). The pH levels improved (p>0.05) between 6.7 to 6.8 where the rumen electrolytes (Ca, Na and K) increased (p<0.01) with increased levels of TMOW. Rumen moisture, dry matter and fat content were (p<0.01) influenced by TMOW diets while ash content was (p<0.01) influenced by the TMOW. Crude protein, ether extract, crude fibre and carbohydrate were not affected (p<0.01; p<0.05) affected. It is good to note that, the microbial community of snail used in the pre-feeding fermentation of municipal organic waste had influence in the physiology and rumen microbial ecology at interface with the goat, enhanced improved the organic matter degradation and feed quality, of the highly fibrous municipal organic solid waste.

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