3 edition of The influence of ultrasonic vibrations upon the physical features of activated sludge. found in the catalog.
The influence of ultrasonic vibrations upon the physical features of activated sludge.
Thomas Robert Wallin
1967 by Dept. of Civil Engineering, University of Illinois in Urbana .
|Series||Civil engineering studies; sanitary engineering series, no. 43|
|LC Classifications||TD756 .W34|
|The Physical Object|
|Pagination||xi, 101 l.|
|Number of Pages||101|
|LC Control Number||72627487|
Ultrasonic disintegration is a method for breakup of microbial cells to extract intracellular material. Ultrasound-activated sewage sludge disintegration could positively affect anaerobic digestion of sewage sludge at sewage treatment plants (STPs). Due to sludge disintegration, organic compounds are transferred from the sludge solids into the aqueous phase resulting in an . Activated sludge is a flocculated suspension of living and dead microorganisms enmeshed together in a polymer matrix along with some organic and inorganic materials. Extracellular polymers, main components of which are the polysaccharides, proteins, and nucleic acids, act as a protective barrier to the living microbial community, and give the Cited by: Activated Sludge - we discuss the observation, testing, and calculation procedures that provide data about the status of the activated sludge process. In addition, we discuss in depth how to apply this data to the business of controlling your activated sludge treatment process. • A tank upstream of the main aerobic portion of the activated sludge process that is designed to control sludge settleability by metabolic or kinetic means – Metabolic control – Due to the way the organisms get food and energy – Kinetic control – Due to the growth rate of the organism under different conditions of growth (SRT)File Size: KB.
sludge volume index (svi) The sludge volume index (SVI), introduced by Mohlman in , has become the standard measure of the physical characteristics of activated sludge solids. It is defined as "the volume in ml occupied by 1 g activated sludge after settling the .
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The experimental steady state viscosities were fitted by the Oswald–de Waele equation: (7) η e = K γ ˙ n − 1 where γ ˙ is the shear rate, K is the consistency index and n is the power law index.
Table 2 shows the values of these parameters that best fits the experimental viscosities for the sludge as a function of ultrasonic specific energies. The consistency index decreases and the Cited by: The AD of sludge is a complex process that converts degradable organic compounds to methane (CH 4) and carbon dioxide (CO 2) in the absence of elemental oxygen with a series of microbiological conversion pathway of the substrate to biogas (mainly CH 4 and CO 2) occurs in four stages, namely, hydrolysis, acidogenesis, acetogenesis and methanogenesis by three different Cited by: Municipal wastewater sludge, particularly waste activated sludge (WAS), is more difficult to digest than primary solids due to a rate-limiting cell lysis step.
The cell wall and the membrane of prokaryotes are composed of complex organic materials such as peptidoglycan, teichoic acids, and complex polysaccharides, which are not readily by: The activated sludge process is widely used by large cities and communities where large volumes of wastewater must be highly treated economically.
Activated sludge process plants are good choices too for isolated facilities, such as hospitals or hotels, clus-ter situations, subdivisions, and small communities. The process A basic activated sludge. Moreover, the working mechanisms behind the treatment and the influence of various process conditions, including power density/intensity, specific energy input, ultrasonic frequency, duration of ultrasonication (i.e., partial and complete ultrasonication, solids concentration, and type of sludge on the ultrasonic processing of sludge is Cited by: Activated sludge reactor (plug flow reactor with recycle) Limitations of the models Aeration requirements Types of aerators Types of suspended growth processes Conventional activated sludge Step aeration or step feed process Tapered aeration process conditions in the aeration tank and this might influence the activated sludge flocs; some literature report on floc break-up (Das et al.
) whereas others report of the formation of smaller but denser flocs at high homogenous turbulence flow regimes such as in air-lift reactors whereas larger. The WTOS system utilized Hach Lange instrumentation and a process model based upon the ASM1 activated sludge model (Thornton et al., ).
One of the first full-scale installations controlled with the WTOS system was apopulation equivalent four-stage Bardenpho plant with methanol addition in the second anoxic zone. activated sludge microbes and converted to biomass, water, carbon dioxide, and other gases • Nitrification – The process through which ammonia is oxidized to nitrite and nitrate • Denitrification – A process by which nitrates and nitrites are converted to gaseous end products, primarily nitrogen Size: 1MB.
: Activated Sludge: Theory and Practice (Oxford Science Publications) (): N. Gray: BooksCited by: The activated sludge process is one of the most commonly employed domestic and industrial waste treatment process.
Different types of mathematical models have been proposed for design and operation of this process, most of which do not consider the relationship betweenCited by: 2.
Activated sludge is an enrichment culture of micro and macro organisms that remove (or change) components considered to be Size: 2MB. Sewage sludge consists mainly of microbial cells and water.
The amount of water that can be removed from sewage sludge is very high and is about % for primary sludge and % for secondary sludge. Nevertheless, water removal depends not only on the dewatering process, but also on water’s physical position in the sludge.
I havent' read the entire book yet, but so far, the chapters revolving around microbial growth processes and reactor kinetics are described very thoroughly which gives the reader are deep understanding of the subject. One drawback is the missing answers for the "study problems" - one would like to know whether if the problems has been solved 4/5(1).
In this paper, a 90th order activated sludge process system is explored. From the original high order system, a disturbance between 1rad/s to 10rad/s are observed, hence frequency weighted model. Oxygen uptake rate (OUR) of the activated sludge (AS) was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHz for 0–40 min with ultrasonic intensities of 0– Therefore disintegration of sewage sludge is a promising method to enhance anaerobic digestion rates and lead to reduce the volume of sludge digesters.
The addition of disintegrated surplus activated sludge and/or foam to the process of sludge anaerobic digestion can lead to markedly better effects of sludge handling at wastewater treatment plants.
The activated sludge process is a common method of treat- ing organic wastewater; however, as wastewater is processed, excess sludge is produced and problems such. The influence of ultrasonic disintegration on sewage sludge centrifugation 37 gated: i) non-treated sludge (N), ii) sonicated sludge (UD), iii) sludge sonicated and con-ditioned by chemical substances (cement, ash and gypsum).
The values of the rate of rotation ( and r.p.m. for 5 minutes) were determined experimentally. Five. Sludge digestion in the reactor 31 Recirculation of the activated sludge 34 Production and removal of excess sludge 39 Oxygen requirements 48 Nutrient requirements 55 Inﬂuence of the temperature 58 Functional relations with the sludge age 59 3 Design of continuous-ﬂow activated sludge reactors for organic.
The second major debate revolved around the fundamental activated sludge mechanism; whether it was a physical-chemical operation or a biological process.\u48,50\d Baly theorized that differential charging between sewage colloids and floc matrixes resulted in an electrostatic attraction and consequent clarification.\u48\d Along similar lines.
Two main mechanisms for sludge disintegration and protein solubilization are associated with ultrasonic pretreatment. At a low ultrasonic frequency, the phenomenon of cavitation predominates.
In order to enhance the degradation efficiency of waste activated sludge (WAS) by thermophilic aerobic digestion, an ultrasonic pretreatment was examined.
It was observed that ultrasonic pretreatment increased the solubilization of organic matter in the WAS and that the solubilization ratio of the organics increased during the first 30 min but did not extensively increase thereafter.
Abstract. The main objective of this work was to enhance the dewatering efficiency of sewage sludge by ultrasonic irradiation. Low-field 1 H nuclear magnetic resonance (LF-NMR) was used to deduce the moisture distribution in sewage sludge.
Experiments were carried out to investigate the effects of ultrasonic frequencies (20, 25, 30, 35 and 40 kHz) and treatment time (1, 2, 3, 5 and 10 Cited by: 2. A practical, hands-on guide to using the microscope to analyze activated sludge in wastewater treatment The microscope provides the wastewater treatment plant operator with a special tool for process control and troubleshooting of the activated sludge process.
The operator can read the organisms and use them as bioindicators to determine if. product of activated sludge disintegration. The study showed that the propagation of ultrasonic wave was highly disintegrating factor, generating a product of the characteristics of concentrated organic solution.
By sonication of activated sludge the dissolved phase was enriched particularly in significant amounts of nitrogen and phosphorus.
The influences of influent suspended solids and sludge SRT and process temperature on sludge yield are shown graphically in Fig Fig Influence of process parameters on AS process sludge yield (equations, and ) While SRT is the most appropriate process design parameter, the sludge loading rate (SLR) is also.
Overview. Activated Sludge Separation Problems: Theory, Control Measures, Practical Experiences, Second Edition, describes the most common activated sludge separation problems and explains the main reasons for the growth of the different filamentous microorganisms in activated sludge. The book summarizes the identification techniques for important groups of activated sludge.
Sludge Treatment The primary sludge pumped from the bottom of the primary clarifiers in step three, along with the continuous flow of waste activated sludge from the aeration / activated sludge process in step four, must be treated to reduce volume and produce a usable end product.
The sludge treatment process involves four steps as described here. “activated sludge concept” CE Reyes Lec. sponsored by grocers (nutrients, fertilizers) c. first full-scale plant in Salford, Engl GPD Eight more full-scale plants in UK Edward Bartow of UI visited Fowler in England in Lambert N, Van Eyck K, Feremans J, Van den Broeck R, Smets I, Dewil R () Ultrasonic sludge disintegration in nutrient deficient activated sludge wastewater treatment plants.
In: 2nd IWA conference on holistic sludge management, Malmö, Sweden, 7–9 June Google ScholarAuthor: N. Lambert, P. Van Aken, I. Smets, R. Dewil. Presents and explains the theory of sludge treatment Covers US and European disposal regulations and practices. Intended for advanced students and practitioners of wastewater engineering, this text offers the theory and quantitative rationale for treating wastewater and industrial sludges, with public safety and efficiency in s: 1.
changes in physical, chemical, and biological aspects of a sludge. This work primarily focuses upon the eﬀects of ultrasonic treatment on the physical (ﬂoc size, ﬁlterability, settleability, bound water content, and surface charge), chemical (chemical.
Stanford Libraries' official online search tool for books, media, journals, databases, government documents and more. Activated sludge produced in the wastewater treatment process has complex physical and chemical characteristics.
Sludge consists mainly of water that is partially bound into sludge flocs. Sludge flocs consist of extracellular polymeric substances (EPS), micro- acterization of activated sludge after ultrasonic treatment.
Most studies. So, it was concluded that higher efficient disintegration effect could be obtained by combined effects of ultrasonic and mechanical treatment.
AB - Excess Sludge was disintegrated by combined effects of ultrasonic and mechanical treatment. Investigation experiments were carried out to disintegrate excess sludge by combined both treatment : Zhu Tong, Han Jin, Liu Jianfeng, Wang Zhan, Luan Xianyu, Xie Yuanhua, Wang Yang, Huang Yonggang.
View Test Prep - activated sludge from book from CVNG at University of Texas. Intrudurmm to Environmental Engineering Fourth Edition Chapter 6: Wastewater Treatment (Activated Sludge. Sludge retention time (SRT) is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N 2 O) in biological nutrient removal (BNR) processes.
Four laboratory-scale sequencing batch reactors (SBRs), namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d. ACTIVATED SLUDGE Perry L. McCarty and C. Broder sen Extended aeration activated sludge plants have fulfilled a need for high efficiency treatment of small volume wastes of both domestic and industrial origin.
These plants are usually de signed without primary sedimentation tanks and employ an "extended aera tion period," for the purpose of aero. Activated sludge with its living organisms has the property of absorbing or adsorbing colloidal and dissolved organic matter.
The biological organisms utilize the absorbed material as food and convert it to inert insoluble solids and new bacterial cells. Much of this conversion is a step-by-step process. Contents: Process Theory Kinetics and Sludge Quality Control: Activated Sludge Process - Process Theory - Activated Sludge Separation Problems - References Activated Sludge Treatment of Municipal Wastewater U.S.A.
Practice: General Approach - Clarifier Design - Aeration Tank (Reactor) Design - Appurtenance Design - Configurations - ReferencesEurope.Breaking down sludge floc (sonodyspergation effect) and destruction of the cell membranes of microorganisms forming floc is a direct effect of ultrasonic disintegration of sludge excess.
This results in release of organic material by liquid sludge (the sonolysis effect). Desired technological effects of the disintegration are: to shorten the hydrolytic phase of fermentation, to .pected. Sludge volume index deter minations were conducted using vari ous concentrations of sludge from sev eral activated sludge plants.
The re sults (Figure 2) indicate that no con sistent relationship seems to exist. The rapid increase of the SVI with increasing concentrations is because of the failure of the sludge to agglom.