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Nonoxidative removal of organics in the activated sludge process.

Modin O, Persson F, Wilén BM, Hermansson M - Crit Rev Environ Sci Technol (2016)

Bottom Line: Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics.Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products.Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants.

View Article: PubMed Central - PubMed

Affiliation: Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of Technology , Gothenburg , Sweden.

ABSTRACT

The activated sludge process is commonly used to treat wastewater by aerobic oxidation of organic pollutants into carbon dioxide and water. However, several nonoxidative mechanisms can also contribute to removal of organics. Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics. Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products. Recently, several environmental, economic, and technological drivers have stimulated research on nonoxidative removal of organics for wastewater treatment. In this paper, we review these nonoxidative removal mechanisms as well as the existing and emerging process configurations that make use of them for wastewater treatment. Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants.

No MeSH data available.


Schematic of a PHA-producing wastewater treatment plant.
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f0008: Schematic of a PHA-producing wastewater treatment plant.

Mentions: For PHA production from municipal wastewater using naturally occurring bacteria as inoculum, three principal steps are usually proposed (Dionisi et al., 2004; Coats et al., 2007; Serafim et al., 2008), as depicted in Figure 8. First, fermentation of waste activated sludge and/or municipal wastewater is used to transform the organic content into VFA, which can be effectively used by the PHA-accumulating microorganisms. Typically, the VFAs produced by fermentation are mostly composed of acetic acid and some propionic-, butyric-, and (iso)valeric acids (Coats et al., 2007; Mengmeng et al., 2009; Morgan-Sagastume et al., 2014), with yields in the range of 26% TOCVFA/VSS (g/g) (Mengmeng et al., 2009) and 27% CODVFA/VSS (g/g) (Morgan-Sagastume et al., 2014).Figure 8.


Nonoxidative removal of organics in the activated sludge process.

Modin O, Persson F, Wilén BM, Hermansson M - Crit Rev Environ Sci Technol (2016)

Schematic of a PHA-producing wastewater treatment plant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940897&req=5

f0008: Schematic of a PHA-producing wastewater treatment plant.
Mentions: For PHA production from municipal wastewater using naturally occurring bacteria as inoculum, three principal steps are usually proposed (Dionisi et al., 2004; Coats et al., 2007; Serafim et al., 2008), as depicted in Figure 8. First, fermentation of waste activated sludge and/or municipal wastewater is used to transform the organic content into VFA, which can be effectively used by the PHA-accumulating microorganisms. Typically, the VFAs produced by fermentation are mostly composed of acetic acid and some propionic-, butyric-, and (iso)valeric acids (Coats et al., 2007; Mengmeng et al., 2009; Morgan-Sagastume et al., 2014), with yields in the range of 26% TOCVFA/VSS (g/g) (Mengmeng et al., 2009) and 27% CODVFA/VSS (g/g) (Morgan-Sagastume et al., 2014).Figure 8.

Bottom Line: Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics.Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products.Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants.

View Article: PubMed Central - PubMed

Affiliation: Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of Technology , Gothenburg , Sweden.

ABSTRACT

The activated sludge process is commonly used to treat wastewater by aerobic oxidation of organic pollutants into carbon dioxide and water. However, several nonoxidative mechanisms can also contribute to removal of organics. Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics. Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products. Recently, several environmental, economic, and technological drivers have stimulated research on nonoxidative removal of organics for wastewater treatment. In this paper, we review these nonoxidative removal mechanisms as well as the existing and emerging process configurations that make use of them for wastewater treatment. Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants.

No MeSH data available.