Increase of nitrification efficiency at waste water treatment by implementation of bioaugmentation process

2014 ◽  
Vol 9 (4) ◽  
pp. 551-557
Author(s):  
Y. V. Mikhailova ◽  
M. V. Kevbrina ◽  
V. A. Grachev ◽  
Y. A. Nikolaev ◽  
V. G. Aseeva
Keyword(s):  
Activated Sludge ◽  
Specific Activity ◽  
Waste Water Treatment ◽  
Nitrifying Bacteria ◽  
Ammonium Concentration ◽  
Low Oxygen ◽  
The Stability ◽  
University Of Cape Town ◽  
The University ◽  
Low Oxygen Concentration

Low content of ammonia in the treated water is one of the most important indicators of the efficiency of biological wastewater treatment. Oxidation of ammonium to nitrate (nitrification) is carried out by nitrifying bacteria, which have low growth rates and are very sensible to certain unfavorable technological factors, such as low oxygen concentration and toxicants). To stabilize the number of nitrifying bacteria, increasing their activity in bioreactors with activated sludge and, therefore, to achieve stable and efficient removal of nitrogen compounds, various techniques are used, one of which is bioaugmentation technology. Bioaugmentation implies addition of the necessary microorganisms or creation of the conditions favoring their development in order to increase the specific activity of biological systems, such as activated sludge. In the Engineering and Technological Centre of JSC ‘Mosvodokanal’ for the first time in world practice, we studied the efficiency of nitrification in a plant operating under the scheme of the University of Cape Town process, in combination with an additional bioaugmentation reactor. Activated sludge in the reactor was enriched with nitrifying bacteria. At higher ammonium loads, which were modeled by adding the liquid phase of digested sludge, the main line did not remove ammonium to the maximum permissible concentration for fishery water bodies. The use of a bioaugmentation reactor resulted in ammonium concentration decrease from 40–50 to 0.4 mg N-NH4/l. This approach increased the stability of the activated sludge nitrifying bacteria to toxicants (thiourea).

Simultaneous Nitrification-Denitrification Processes in Activated Sludge Plants: Performance and Applicability

1999 ◽  
Vol 40 (4-5) ◽  
pp. 187-194 ◽  
Author(s):  
C. Collivignarelli ◽  
G. Bertanza
Keyword(s):  
Activated Sludge ◽  
Waste Water Treatment ◽  
Electric Energy ◽  
Low Oxygen ◽  
Total N ◽  
Electric Energy Consumption ◽  
N Removal ◽  
Aeration System ◽  
Anoxic Basin ◽  
Removal Efficiencies

This paper deals with the development of technologies aimed to upgrade existing waste water treatment plants, paying attention to high process efficiencies and low costs. We established conditions for good N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimental process is based on establishing conditions in the biological reactor which allow simultaneous nitrification and denitrification without alternating (in time or in space) anoxic and aerobic phases; the aeration system is controlled by means of dissolved oxygen and/or redox potential measurements. The research was carried out on two real plants (design size: 2,500 p.e. and 440,000 p.e. respectively). The main advantages of this process (even if some aspects are still under investigation) are: total N removal efficiencies similar to a pre-denitrification process, without the need for an anoxic basin and decrease of operating costs (savings in electric energy consumption in particular) due to the low oxygen concentration required in the biological reactor.

First results from a screening of filamentous organisms present in Buenos Aires's activated sludge plants

2002 ◽  
Vol 46 (1-2) ◽  
pp. 119-122 ◽  
Author(s):  
W.D. Di Marzio
Keyword(s):  
Activated Sludge ◽  
Dominant Species ◽  
Filamentous Bacteria ◽  
Low Oxygen ◽  
Morphologic Characteristics ◽  
Nocardia Sp ◽  
First Results ◽  
Aerobic Reactor ◽  
Dominant Bacteria ◽  
Low Oxygen Concentration

Activated sludge samples from municipal and industry plants were evaluated with the aim to recognise the mainly filamentous bacteria found. The routine tests recommended were performed: Gram, Neisser, PHB-Nilo blue epifluorescence reaction and S. The morphologic characteristics were determined. Correlation between environmental conditions and abundance of dominant bacteria were made. All plants were completely mixed configurations with anoxic reactor for denitrification ahead of main aerobic reactor. Also all systems were working at low F/M values or high sludge age (> ten days) and in some cases with low oxygen concentration. The dominant species were Type 021N, Thiothrix I, Sphaerotilus natans, Microthrix parvicella, Nocardia sp, Type 1701, Type 1863, Type 0041 and Type 0092.

scholarly journals Oxygen Gradients and Structure of the Ciliate Assemblages in Floodplain Lake

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2084 ◽  
Author(s):  
Roman Babko ◽  
Tetiana Kuzmina ◽  
Yaroslav Danko ◽  
Joanna Szulżyk-Cieplak ◽  
Grzegorz Łagód
Keyword(s):  
Oxygen Concentration ◽  
High Amplitude ◽  
Ciliated Protozoa ◽  
Low Oxygen ◽  
Ciliate Species ◽  
Oxygen Gradients ◽  
Quantitative Development ◽  
The Stability ◽  
Low Oxygen Concentration

This paper presents the results of studies on the structure of the ciliate population in a freshwater lake. The classification of the ciliated communities based on the analysis of the distribution of ciliate population density in the lake along the oxygen gradients, taking into account their oxygen preferences, was proposed. It was shown that the distribution of ciliated protozoa in the space of a reservoir is determined not by such spatial units as the water column, bottom, and periphytal, but by the oxygen gradients. Four types of habitats with different oxygen regimes were distinguished: With stably high oxygen concentration, stably low oxygen concentration, stably oxygen-free conditions, and conditions with a high amplitude of diurnal oxygen variations. The location of these habitats in the space of the lake and their seasonal changes were determined. On the basis of the quantitative development of ciliate populations, zones of optima and tolerance ranges of some ciliate species in the oxygen gradient were established. The oxygen preferences were established for the species from four distinguished assemblages: Microoxyphilic, oxyphilic, euryoxyphilic, and anoxyphilic (anaerobic). The presence or the absence of a certain type of assemblage in the reservoirs depends solely on the parameters of the oxygen gradients. The diversity of the ciliated protozoa in water bodies also depends on the stability and diversity of the oxygen gradients.

scholarly journals Characteristics of Low-Oxygen Oxidation Ditch with Improved Nitrogen Removal

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3603
Author(s):  
Elena Gogina ◽  
Igor Gulshin
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Settling Tank ◽  
Reaction Rates ◽  
Organic Load ◽  
Pcr Analysis ◽  
Low Oxygen ◽  
Low Concentrations ◽  
The Stability ◽  
Oxygen Oxidation

This article presents a study on the operational stability of laboratory oxidation ditches, designated for synthetic and real wastewater and operable at low concentrations of dissolved oxygen. The project encompassed the stability monitoring of activated sludge depending on sedimentation characteristics and hydrobiological indicator microorganisms, determining (1) the size of sludge floccules and (2) the main functional groups of microorganisms identified in the course of the PCR analysis and reaction rates, plotted using the Michaelis–Menten enzymatic kinetics for the mixed culture biomass. The most stable system involves a bioreactor featuring dissolved oxygen gradients that range from 1.9 to 0.15 mg/L s, a specific organic load of 0.21 gBOD/g/d and a hydraulic retention time of 12 h. A built-in settling tank allows the consideration of the potential generation of large floccules of activated sludge in oxidation ditches (at least 300 μm) that increase the efficiency of simultaneous nitrification and denitrification. Thus, the obtained reaction rates can be used in calculations and simulations of the operation of oxidation ditches at low concentrations of dissolved oxygen.

DESIGN PLANNING WASTEWATER TREATMENT PLANT OF NATA DE COCO INDUSTRY WITH THE ACTIVATED SLUDGE PROCESS

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Dinda Rita K. Hartaja ◽  
Imam Setiadi
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Appropriate Technology ◽  
Waste Water Treatment Plant ◽  
Activated Sludge Process ◽  
High Level

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL

Double Thoughts

2018 ◽  
Author(s):  
Andrew Dean
Keyword(s):  
Literary Criticism ◽  
Jacques Derrida ◽  
Postcolonial Theory ◽  
Cape Town ◽  
Literary Texts ◽  
Paul De Man ◽  
Literature And Philosophy ◽  
De Man ◽  
University Of Cape Town ◽  
The University

Coetzee’s interest in destabilizing the boundaries of literature and philosophy is most evident in later fictions such as Elizabeth Costello. But as Andrew Dean argues in this chapter, this interest in moving across boundaries in fact originates much earlier, in Coetzee’s quarrel with the institutions and procedures of literary criticism. Coetzee used the occasion of his inaugural professorial lecture at the University of Cape Town (Truth and Autobiography) to criticize the assumption that literary criticism can reveal truths about literature to which literary texts are themselves blind. Influenced in part by such figures as Jacques Derrida and Paul de Man, Coetzee posed a series of challenging questions about the desires at stake in the enterprise of literary criticism. Developing these thoughts, Dean explores the way in which Coetzee’s earlier fiction, including such texts as Foe (1986), is energized by its quarrelsome relationship with literary criticism and theory, especially postcolonial theory.

Effect of low oxygen concentration on activation of inflammation by Helicobacter pylori

2021 ◽  
Vol 560 ◽  
pp. 179-185
Author(s):  
Adiza Abass ◽  
Tokuju Okano ◽  
Kotchakorn Boonyaleka ◽  
Ryo Kinoshita-Daitoku ◽  
Shoji Yamaoka ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Oxygen Concentration ◽  
Low Oxygen ◽  
Low Oxygen Concentration

Decolonizing Science, Digitizing the Occult: Theory from the Virtual South

2021 ◽  
Vol 64 (1) ◽  
pp. 86-104
Author(s):  
Sasha Newell
Keyword(s):  
Social Media ◽  
Intimate Relationships ◽  
Digital Technology ◽  
World Wide ◽  
Western Science ◽  
The World ◽  
University Of Cape Town ◽  
The University ◽  
Second World ◽  
Forms Of Knowledge

AbstractIn this article Newell uses two case studies to explore one of the central threads of Mbembe’s Abiola lecture, the idea that there is a relationship between the plasticity of digital technology and African cosmologies of the deuxième monde. One case concerns the viral YouTube video #sciencemustfall, in which students at the University of Cape Town criticize “Western” science and demand that African forms of knowledge such as witchcraft be incorporated into the meaning of science. The second case considers fieldwork among the brouteurs of Côte d’Ivoire, internet scammers who build intimate relationships on false premises using social media. They acquire shocking amounts of wealth in this way which they display on their own social media accounts. However, they are said to use occult means to seduce and persuade their virtual lovers, trapping their prey in the sticky allure of the world wide web. Newell uses both examples to highlight the overlaps between the transformational efficacies embedded in both occult ontologies and digital worldings, calling for the possibility of using African cosmologies of the second world to produce a ‘theory from the south’ of virtual sociality.

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