Wastewater Treatment

Henze, Mogens; Harremoës, Poul; Jansen, Jes Cour; Arvin, Erik

doi:10.1007/978-3-662-22605-6

Cited by 135 publications

(90 citation statements)

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“…Carbon content of the substrates under study fell within the range of 36.3-55.7% TS, and organic nitrogen content 1.45-1.87% TS. For an anaerobic reactor to function properly, the dry matter content of the feedstock should be within the range from 5 to 15 g TS l -1 (Henze et al, 1997). In the course of the study the average concentration of the bioreactor feedstock was 6% TS.…”

Section: Resultsmentioning

confidence: 99%

Development of optimum substrate compositions in the methane fermentation process

Lalak¹,

Kasprzycka²,

Paprota³

et al. 2015

International Agrophysics

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The aim of the study was to assess the potential of organic wastes from the agriculture and food industry as co-substrate for biogas production, on the basis of physical and chemical parameters analysis and biogas yield in the process of methane fermentation. The experimental material consisted of carrot pomace, kale by-products and maize silage. Methane fermentation was conducted in bioreactors equipped with an automatic control and measurement system. The study indicated correct physicochemical properties in terms of high content of dry organic matter and also correct C/N ratio. That was reflected in high biogas yields which amounted to, respectively, 558 N dm3kg−1VS−1for carrot pomace and kale by-products, and 526 N dm3kg−1VS−1for maize silage. The study showed that the intensity of biogas production was varied and depended on the composition of fermented mixtures. Methane fermentation of organic waste mixtures significantly increased the amount of biogas efficiency compared to the fermentation of individual substrates. The successful run of the experiment indicates that a mixture composed of carrot pomace and kale by-products is a good substrate for the production of biogas.

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Section: Resultsmentioning

confidence: 99%

Development of optimum substrate compositions in the methane fermentation process

Lalak¹,

Kasprzycka²,

Paprota³

et al. 2015

International Agrophysics

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“…In contrast to textbook knowledge (5,19), Nitrospira-like bacteria, not Nitrobacter spp., are the dominant nitrite oxidizers both in most full-scale wastewater treatment plants and in laboratory scale reactors (22,36,43,48). Based on fluorescence in situ hybridization (FISH) combined with microelectrode measurements, it has been suggested that Nitrospira-like nitrite oxidizers represent K strategists adapted to low nitrite and oxygen concentrations, while Nitrobacter sp., as an r strategist, thrives if nitrite and oxygen are present in higher concentrations (42).…”

mentioning

confidence: 85%

In Situ Characterization of Nitrospira -Like Nitrite-Oxidizing Bacteria Active in Wastewater Treatment Plants

Daims

Nielsen

et al. 2001

Appl Environ Microbiol

719

540

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Uncultivated Nitrospira-like bacteria in different biofilm and activated-sludge samples were investigated by cultivation-independent molecular approaches. Initially, the phylogenetic affiliation of Nitrospira-like bacteria in a nitrifying biofilm was determined by 16S rRNA gene sequence analysis. Subsequently, a phylogenetic consensus tree of the Nitrospira phylum including all publicly available sequences was constructed. This analysis revealed that the genus Nitrospira consists of at least four distinct sublineages. Based on these data, two 16S rRNA-directed oligonucleotide probes specific for the phylum and genus Nitrospira, respectively, were developed and evaluated for suitability for fluorescence in situ hybridization (FISH). The probes were used to investigate the in situ architecture of cell aggregates of Nitrospira-like nitrite oxidizers in wastewater treatment plants by FISH, confocal laser scanning microscopy, and computer-aided three-dimensional visualization. Cavities and a network of cell-free channels inside the Nitrospira microcolonies were detected that were water permeable, as demonstrated by fluorescein staining. The uptake of different carbon sources by Nitrospira-like bacteria within their natural habitat under different incubation conditions was studied by combined FISH and microautoradiography. Under aerobic conditions, the Nitrospira-like bacteria in bioreactor samples took up inorganic carbon (as HCO 3 ؊ or as CO 2 ) and pyruvate but not acetate, butyrate, and propionate, suggesting that these bacteria can grow mixotrophically in the presence of pyruvate. In contrast, no uptake by the Nitrospira-like bacteria of any of the carbon sources tested was observed under anoxic or anaerobic conditions. Nitrification, the oxidation of ammonia to nitrate catalyzed by bacteria, is a key part of global nitrogen cycling (37). In the first step of nitrification, chemolithoautotrophic ammonia oxidizers transform ammonia to nitrite, which is subsequently oxidized to nitrate by the nitrite-oxidizing bacteria (8). All isolated chemolithoautotrophic, nitrite-oxidizing bacteria belong to one of four different genera (7) Nitrobacter (alpha subclass of Proteobacteria), Nitrococcus (gamma subclass of Proteobacteria), Nitrospina (delta subclass of Proteobacteria), and Nitrospira (phylum Nitrospira). While species of the genus Nitrobacter have been isolated from a variety of environments, including soil and fresh water, it was long assumed that the other three genera were confined to marine environments (7). In recent studies, however, bacteria related to the genus Nitrospira were also found to occur in different nonmarine habitats. While the first described species of this genus, Nitrospira marina, was isolated from ocean water (49), the second isolated species, N. moscoviensis, was cultured from an iron pipe of a heating system in Moscow, Russia (16). These two species are the only cultivated representatives of the genus Nitrospira, but numerous related bacteria have recently been detected by comparative analy...

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“…When treating wastewater, it is usually stated that the ratio of COD:N:P in the wastewater to be treated should be approximately 100:5:1 for aerobic treatment and 250:5:1 for anaerobic treatment (Metcalf and Eddy, 1991 USEPA, 1995;Henze et al, 1997;Maier, 1999 a). For anaerobic treatment, the required nitrogen and phosphorous concentrations is lower than the case for aerobic treatment due to the fact that anaerobic treatment produces only 20% sludge compared to aerobic treatment.…”

Section: Introductionmentioning

confidence: 99%

Nutrients requirements in biological industrial wastewater treatment

Ammary¹

2004

Afr. J. Biotechnol.

110

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Wastewaters from olive mills and pulp and paper mill industries in Jordan have been characterized and treated using laboratory scale anaerobic and aerobic sequencing batch reactors, respectively. Nutrient requirements for these two industrial wastewaters were found to be less than what is usually reported in the literature for C:N:P ratio of 100:5:1 for aerobic treatment and 250:5:1 for anaerobic treatment. This was ascribed to the low biomass observed yield coefficients and relatively low removal efficiencies in these wastewaters. It was found that for anaerobic treatment of olive mills wastewater COD:N:P ratio of about 900:5:1.7 was able to achieve more than 80% COD removal. The observed biomass yield was about 0.06 kg VSS per kg of COD degraded. For extended aeration aerobic treatment of pulp and paper mill wastewater COD:N:P ratio of about 170:5:1.5 was able to achieve more than 75% COD removal. The observed biomass yield was about 0.31 kg VSS per kg of COD degraded. In both these wastewaters nutrients were not added. A simple formula is introduced to calculate nutrient requirements based on removal efficiency and observed biomass yield coefficient.

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Wastewater Treatment

Cited by 135 publications

References 0 publications

Development of optimum substrate compositions in the methane fermentation process

Development of optimum substrate compositions in the methane fermentation process

In Situ Characterization of Nitrospira -Like Nitrite-Oxidizing Bacteria Active in Wastewater Treatment Plants

Nutrients requirements in biological industrial wastewater treatment

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