Physicochemical and biological performance of expanded granular sludge bed reactors treating long-chain fatty acids

Hwu, Ching-Shyung; Lier, J.B. van; Lettinga, G.

doi:10.1016/s0032-9592(97)00051-4

Cited by 57 publications

(39 citation statements)

References 18 publications

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“…Hwu et al [40] studied the influence of hydrodynamics, temperature, and co-substrates (glucose and acetate) on the performance of anaerobic digestion of oleic acid in EGSB reactors. Under similar experimental conditions, as in studies by Rinzema [74] and Syutsubo et al [92] (upflow velocity of 3.4-4 m/h), and in the absence of cosubstrates, COD removal efficiencies of 66 and 73% [90] were attained under thermophilic (55°C) conditions at hydraulic retention times of 3 and 6 h, respectively.…”

Section: The Influence Of Co-substrates On the Biodegradation Of Lipimentioning

confidence: 99%

Behavior of lipids in biological wastewater treatment processes

Chipasa

Mędrzycka

2006

J IND MICROBIOL BIOTECHNOL

132

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Lipids (characterized as oils, greases, fats and long-chain fatty acids) are important organic components of wastewater. Their amount, for example, in municipal wastewater is approximately 30-40% of the total chemical oxygen demand. The concern over the behavior of lipids in biological treatment systems has led to many studies, which have evaluated their removal, but still the exact behavior of lipids in these processes is not well understood. In this review, we discuss the current knowledge of how lipids/fatty acids affect both aerobic and anaerobic processes and specific methods that have been used in an attempt to enhance their removal from wastewater. Overall, the literature shows that lipids/fatty acids are readily removed by biological treatment methods, inhibitory to microbial growth as well as the cause of foaming, growth of filamentous bacteria and floc flotation.

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Section: The Influence Of Co-substrates On the Biodegradation Of Lipimentioning

confidence: 99%

Behavior of lipids in biological wastewater treatment processes

Chipasa

Mędrzycka

2006

J IND MICROBIOL BIOTECHNOL

132

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“…Over decades, a number of technologies for anaerobic treatment have been created (32), and applications of these processes are now being extended to more complex wastewaters (5,11,18), to low-strength wastewaters (12, 17), and to wastes and wastewaters under extreme temperature conditions (19,26,41). Thermophilic anaerobic processes (normally operated between 50 and 60°C) are those developed in recent decades for the treatment of industrial wastes and wastewaters which are discharged at high temperatures (47, 48).…”

mentioning

confidence: 99%

Cultivation and In Situ Detection of a Thermophilic Bacterium Capable of Oxidizing Propionate in Syntrophic Association with Hydrogenotrophic Methanogens in a Thermophilic Methanogenic Granular Sludge

Imachi

Sekiguchi

Kamagata

et al. 2000

Appl Environ Microbiol

105

104

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The thermophilic, anaerobic, propionate-oxidizing bacterial populations present in the methanogenic granular sludge in a thermophilic (55°C) upflow anaerobic sludge blanket reactor were studied by cultivation and in situ hybridization analysis. For isolation of propionate-degrading microbes, primary enrichment was made with propionate as the sole energy source at 55°C. After several attempts to purify the microbes, a thermophilic, syntrophic, propionate-oxidizing bacterium, designated strain SI, was isolated in both pure culture and coculture with Methanobacterium thermoautotrophicum. Under thermophilic (55°C) conditions, strain SI oxidized propionate, ethanol, and lactate in coculture with M. thermoautotrophicum. In pure culture, the isolate was found to ferment pyruvate. 16S ribosomal DNA sequence analysis revealed that the strain was relatively close to members of the genus Desulfotomaculum, but it was only distantly related to any known species. To elucidate the abundance and spatial distribution of organisms of the strain SI type within the sludge granules, a 16S rRNA-targeted oligonucleotide probe specific for strain SI was developed and applied to thin sections of the granules. Fluorescence in situ hybridization combined with confocal laser scanning microscopy revealed that a number of rod-shaped cells were present in the middle and inner layers of the thermophilic granule sections and that they formed close associations with hydrogenotrophic methanogens. They accounted for approximately 1.1% of the total cells in the sludge. These results demonstrated that strain SI was one of the significant populations in the granular sludge and that it was responsible for propionate oxidation in the methanogenic granular sludge in the reactor.Anaerobic processes have been widely used over the past decades for the treatment of municipal and industrial wastewaters as well as solid wastes such as sewage sludge (16,32). Over decades, a number of technologies for anaerobic treatment have been created (32), and applications of these processes are now being extended to more complex wastewaters (5,11,18), to low-strength wastewaters (12, 17), and to wastes and wastewaters under extreme temperature conditions (19,26,41). Thermophilic anaerobic processes (normally operated between 50 and 60°C) are those developed in recent decades for the treatment of industrial wastes and wastewaters which are discharged at high temperatures (47, 48). In addition, because of the higher metabolic activities of thermophiles, thermophilic processes are capable of accommodating a very high loading rate at a feasible removal efficiency (43, 48, 49). Consequently, thermophilic processes also offer an attractive alternative for the treatment of middle-and high-strength wastes and wastewaters holding an ambient temperature. In spite of these advantages, the processes are often found to be less stable and more sensitive to environmental changes than mesophilic processes (42,48). In many cases, poorer effluent quality was reported for thermophilic proce...

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“…Glycerol is further degraded via acidogenesis while LCFA are broken down to acetate, H 2 and CO 2 through the β-oxidation process (syntrophic acetogenesis) (Stryer, 1995). The application of anaerobic digestion of fat-rich wastewaters was hindered by problems related to LCFA adsorption to the biomass, with consequent sludge flotation and washout (Rinzema et al, 1993;Hwu et al, 1998a;Hwu et al, 1998b) and inhibitory or toxic effects of LCFA to different groups of microorganisms such as acetoclastic methanogens (Koster & Cramer, 1987;Rinzema et al, 1994;Angelidaki & Ahring, 1995;Lalman & Bagley, 2001) and to a much less extent to hydrogenotrophic methanogens (Hanaki et al, 1981;Lalman & Bagley, 2001). Besides the potential metabolic inhibition, LCFA accumulation onto the sludge can create a physical barrier or damage the cell wall, with consequent limitations in the transport of substrates and products (Pereira et al, 2005).…”

Section: Lipids In Particular Long-chain Fatty Acids (Lcfas)mentioning

confidence: 99%