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Selective VFA production potential from organic waste streams: Assessing temperature and pH influence
Jon Garcia-Aguirre1, Enrique Aymerich1, Jaime González-Mtnez de Goñi1
1Ceit and Tecnun (University of Navarra), 15 Paseo Manuel de Lardizabal, San Sebastian 20018, Spain.
Bioresource Technology
|August 31, 2017
Summary
This study investigated volatile fatty acid (VFA) production from various waste streams. Optimal conditions, particularly alkaline pH and mesophilic temperatures, significantly enhanced VFA yield from municipal solid waste.
Area of Science:
- Environmental Microbiology
- Biochemical Engineering
- Waste Management
Background:
- Volatile fatty acids (VFAs) are valuable platform chemicals derived from organic waste.
- Optimizing VFA production from diverse waste streams is crucial for sustainable resource recovery.
Purpose of the Study:
- To evaluate the volatile fatty acid (VFA) production potential of seven distinct urban and agroindustrial waste streams.
- To determine the influence of pH and temperature on VFA yield and composition.
Main Methods:
- Batch assays were conducted using seven different waste streams.
- Experiments were performed under varying conditions: acidic (pH 5.5) and alkaline (pH 10) pH, and mesophilic (35°C) and thermophilic (55°C) temperatures.
- Volatile fatty acid (VFA) yield and concentration were quantified using chemical oxygen demand (COD) and soluble COD (sCOD) measurements.
Main Results:
- VFA yield was significantly influenced by temperature and positively correlated with pH.
- Liquid waste streams showed VFA yields between 220-677 mgCOD/gCODfed, while solid waste streams and urban sludge yielded 127-611 mgCOD/gCODfed.
- The organic fraction of municipal solid waste (OFMSW) exhibited the highest VFA concentration (8,320 mgCOD/L) and VFA/sCOD ratio (94%) under alkaline, mesophilic conditions.
Conclusions:
- Selective VFA production, including propionic, butyric, and acetic acids, is feasible.
- Process parameters, specifically pH and temperature, can be adjusted to optimize VFA production from specific waste streams.
- These findings support the potential for scaling up VFA recovery from targeted waste materials.
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