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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.


Size fractionation of municipal (A) and industrial (B) wastewater. (1) This study was carried out by van Nieuwenhuijsen et al. (2004) in the Netherlands with a wastewater having a total COD concentration of 501 mg/L. (2) Dulekgurgen et al. (2006), Turkey, 406 mg/L. (3) Hu et al. (2002), USA, 300 mg/L. (4–6) Sophonsiri and Morgenroth (2004), USA, 309 mg/L, 67,444 mg/L, and 7249 mg/L, respectively. (7) Dogruel et al. (2006), Turkey, 1340 mg/L. (8) Karahan et al. (2008), Turkey, 3100 mg/L. (9) Arslan-Alaton et al. (2009), Turkey, 46,318 mg/L. (10) Dogruel et al. (2013), Turkey, 15,300 mg/L. For ultrafiltration membranes using nominal molecular weight cutoffs (MWCO), MWCO was converted to equivalent particle size assuming the following relationship: Diameter in nm = 2 × 0.066 × (MWCO in Da)0.333 (Erickson 2009).
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f0002: Size fractionation of municipal (A) and industrial (B) wastewater. (1) This study was carried out by van Nieuwenhuijsen et al. (2004) in the Netherlands with a wastewater having a total COD concentration of 501 mg/L. (2) Dulekgurgen et al. (2006), Turkey, 406 mg/L. (3) Hu et al. (2002), USA, 300 mg/L. (4–6) Sophonsiri and Morgenroth (2004), USA, 309 mg/L, 67,444 mg/L, and 7249 mg/L, respectively. (7) Dogruel et al. (2006), Turkey, 1340 mg/L. (8) Karahan et al. (2008), Turkey, 3100 mg/L. (9) Arslan-Alaton et al. (2009), Turkey, 46,318 mg/L. (10) Dogruel et al. (2013), Turkey, 15,300 mg/L. For ultrafiltration membranes using nominal molecular weight cutoffs (MWCO), MWCO was converted to equivalent particle size assuming the following relationship: Diameter in nm = 2 × 0.066 × (MWCO in Da)0.333 (Erickson 2009).

Mentions: Some researchers have done more detailed investigations of size fractions and chemical composition of wastewater organics. Different methods have been used for size fractionation. Early studies often used sedimentation and centrifugation (e.g., Rickert and Hunter, 1971) and the results from several studies are tabulated by Levine et al. (1991) and Sophonsiri and Morgenroth (2004). More recent studies have typically used micro- and ultrafiltration membranes with defined pore sizes (e.g., Karahan et al., 2008). The results from 10 such studies are compiled in Figure 2. In municipal wastewater (Figure 2A), the size fraction <0.001 µm appears to account for around 15–40% of the total COD whereas around 40–60% is associated with the size fraction >1 µm. Industrial wastewaters have highly variable size fractionation patterns (Figure 2B). For example, in textile wastewater about 70% of the COD is <0.001 µm, whereas in swine manure nearly 80% of the COD is associated with the fraction >10 µm.Figure 2.


Nonoxidative removal of organics in the activated sludge process.

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

Size fractionation of municipal (A) and industrial (B) wastewater. (1) This study was carried out by van Nieuwenhuijsen et al. (2004) in the Netherlands with a wastewater having a total COD concentration of 501 mg/L. (2) Dulekgurgen et al. (2006), Turkey, 406 mg/L. (3) Hu et al. (2002), USA, 300 mg/L. (4–6) Sophonsiri and Morgenroth (2004), USA, 309 mg/L, 67,444 mg/L, and 7249 mg/L, respectively. (7) Dogruel et al. (2006), Turkey, 1340 mg/L. (8) Karahan et al. (2008), Turkey, 3100 mg/L. (9) Arslan-Alaton et al. (2009), Turkey, 46,318 mg/L. (10) Dogruel et al. (2013), Turkey, 15,300 mg/L. For ultrafiltration membranes using nominal molecular weight cutoffs (MWCO), MWCO was converted to equivalent particle size assuming the following relationship: Diameter in nm = 2 × 0.066 × (MWCO in Da)0.333 (Erickson 2009).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f0002: Size fractionation of municipal (A) and industrial (B) wastewater. (1) This study was carried out by van Nieuwenhuijsen et al. (2004) in the Netherlands with a wastewater having a total COD concentration of 501 mg/L. (2) Dulekgurgen et al. (2006), Turkey, 406 mg/L. (3) Hu et al. (2002), USA, 300 mg/L. (4–6) Sophonsiri and Morgenroth (2004), USA, 309 mg/L, 67,444 mg/L, and 7249 mg/L, respectively. (7) Dogruel et al. (2006), Turkey, 1340 mg/L. (8) Karahan et al. (2008), Turkey, 3100 mg/L. (9) Arslan-Alaton et al. (2009), Turkey, 46,318 mg/L. (10) Dogruel et al. (2013), Turkey, 15,300 mg/L. For ultrafiltration membranes using nominal molecular weight cutoffs (MWCO), MWCO was converted to equivalent particle size assuming the following relationship: Diameter in nm = 2 × 0.066 × (MWCO in Da)0.333 (Erickson 2009).
Mentions: Some researchers have done more detailed investigations of size fractions and chemical composition of wastewater organics. Different methods have been used for size fractionation. Early studies often used sedimentation and centrifugation (e.g., Rickert and Hunter, 1971) and the results from several studies are tabulated by Levine et al. (1991) and Sophonsiri and Morgenroth (2004). More recent studies have typically used micro- and ultrafiltration membranes with defined pore sizes (e.g., Karahan et al., 2008). The results from 10 such studies are compiled in Figure 2. In municipal wastewater (Figure 2A), the size fraction <0.001 µm appears to account for around 15–40% of the total COD whereas around 40–60% is associated with the size fraction >1 µm. Industrial wastewaters have highly variable size fractionation patterns (Figure 2B). For example, in textile wastewater about 70% of the COD is <0.001 µm, whereas in swine manure nearly 80% of the COD is associated with the fraction >10 µm.Figure 2.

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.