Microbial aggregates in wastewater treatment

1994 ◽  
Vol 30 (8) ◽  
pp. 87-95 ◽  
Author(s):  
Jerzy J. Ganczarczyk
Keyword(s):  
Experimental Data ◽  
Wastewater Treatment ◽  
Shape Factor ◽  
Regression Models ◽  
Settling Velocity ◽  
Shape Factors ◽  
Sludge Flocs ◽  
Stable Conditions ◽  
Factor Function

Basic forms of microbial aggregates generated in wastewater treatment and techniques used to study them, are described and discussed. The role of the free-setting velocity in evaluation of some physical properties of activated sludge flocs is emphasized. Several regression models were applied to correlate the flocs' settling velocity with flocs' size values. For the studied samples a simple linear model proved to be superior to a multiplicative one, and an introduction to this model of a settling shape factor function instead of constant intercepts, provided a very good correlation of the experimental data. It is expected that a difference between shape factors for the most stable conditions of the flocs and those for the flocs under the settling conditions will make it possible to determine softness or stiffness of these microbial aggregates.

Analysis of sludge aggregates produced during electrocoagulation of model wastewater

2015 ◽  
Vol 73 (1) ◽  
pp. 161-166
Author(s):  
B. Załęska-Chróst ◽  
R. Wardzyńska
Keyword(s):  
Wastewater Treatment ◽  
Fractal Dimension ◽  
Settling Velocity ◽  
Paper Industry ◽  
Additional Parameter ◽  
Treatment Control ◽  
Sludge Flocs ◽  
Lower Water Content ◽  
A Current ◽  
Industry Wastewater

This paper presents the results of the study of sludge aggregates produced during electrocoagulation of model wastewater of a composition corresponding to the effluents from the cellulose and paper industry. Wastewater was electrocoagulated statically using aluminium electrodes with a current density of 31.25 A m−2 and 62.50 A m−2. In subsequent stages of the treatment, sludge flocs were collected, their size was studied and their floc settling velocity (30–520 μm s−1) and fractal dimension (D) were determined. The values of D ranged from 1.53 to 1.95 and were directly proportional to the degree of wastewater treatment. Higher values of D were determined for sludge with lower water content (after 24 hours’ settling). Fractal dimension can therefore be used as an additional parameter of wastewater treatment control.

Effect of Porosity on Mechanical Properties of Rubber

1995 ◽  
Vol 68 (2) ◽  
pp. 219-229 ◽  
Author(s):  
A. I. Kasner ◽  
E. A. Meinecke
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Shape Factor ◽  
Compression Modulus ◽  
Stress Strain ◽  
Shape Factors ◽  
Porosity Level ◽  
Apparent Modulus ◽  
Analytical Expressions ◽  
Cylindrical Samples

Abstract Cylindrical samples, with different shape factors and levels of porosity, were prepared from a model EPDM compound and tested in compression. The modulus was reduced considerably with the introduction of porosity, especially when the shape factor was high. The stress-strain curves showed nonlinearity which depends on the shape factor and porosity level, and is related to bubble closure. The apparent modulus of bonded blocks was found to consist of two components: homogeneous compression modulus and a hydrostatic contribution. The first was obtained by compression of blocks between lubricated compression plates. It can be predicted from analytical expressions adapted from composite theories for high density foams in tension. The second arises from the pressure buildup inside the bonded blocks and depends on the shape factor and the porosity level. These moduli, after correcting for compressibility, were used to develop approximate relations describing the stress-strain curves of porous bonded blocks. The stress-strain curves of samples with different shape factors and levels of porosity could be predicted from experimental data or FEA estimates.

Microscopic and enzymatic investigations on biofilms of wastewater treatment systems

1997 ◽  
Vol 36 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Tanja Gschlößl ◽  
Ingrid Michel ◽  
Marion Heiter ◽  
Christian Nerger ◽  
Verena Rehbein
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biological Properties ◽  
Organic Substances ◽  
Operational Conditions ◽  
Sludge Flocs ◽  
And Performance ◽  
The Stability

In biological wastewater treatment inorganic and organic substances are fixed and metabolized by mixed populations of microorganisms forming either activated sludge flocs or biofilms. Not only the type of wastewater but also the operational conditions promote the development of an adapted biocenosis of microorganisms with specialized enzymatic functions. Understanding the biological properties of the microorganisms, it is possible to assess the prevailing conditions in their natural environment. Regular microscopic and enzymatic investigations of activated sludge and biofilms thus improve the assessment of the stability of the processes and support troubleshooting in wastewater treatment plants. While the role of bacteria is often discussed, the importance of ciliated protozoes and metazoes for the maintenance of the stability of biofilm systems is rarely mentioned. In this paper we intend to show some new results of direct microscopic observations in different sorts of biofilm systems focussing upon ciliated protozoes and metazoes. Practical results will demonstrate the relation between enzymatic analysis, microscopic investigations and performance of biofilm systems.

scholarly journals Role of organic matter, nitrogen and phosphorous on granulation and settling velocity in wastewater treatment

2021 ◽  
Vol 40 ◽  
pp. 101967
Author(s):  
M.A. Gomez-Gallegos ◽  
R. Reyes-Mazzoco ◽  
D.X. Flores-Cervantes ◽  
Ayomi Jarayathne ◽  
Ashantha Goonetilleke ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Settling Velocity

The role of settling velocity formulation in the determination of gully pot trapping efficiency: comparison between analytical and experimental data

2012 ◽  
Vol 65 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Annalisa Ciccarello ◽  
Andrea Bolognesi ◽  
Marco Maglionico ◽  
Sandro Artina
Keyword(s):  
Experimental Data ◽  
Particulate Matter ◽  
Settling Velocity ◽  
Disperse Particle ◽  
Trapping Efficiency ◽  
Progressive Loss ◽  
Efficiency Comparison ◽  
Continuous Accumulation

Roadside gully pots are the connecting points between surface runoff and the underground drainage network; therefore they can be considered as the most superficial component of urban drainage systems. Gully pots are supposed to trap particulate matter washed off the catchment surface, but also to collect and convey stormwater into the network. The continuous accumulation of particulate matter results in a progressive loss of the gully pot hydraulic conveyance, thereby increasing the probability of urban flooding during rainstorm events. This study has therefore the objective to determine which variables influence the gully pot capability of retaining solids (efficiency), both experimentally and analytically. Several laboratory tests have been performed on a simple plastic gully pot, with different inflow rates and using both mono and hetero-disperse particle samples. Particular attention has been given to the influence exerted by the way particle settling velocity is expressed: efficiency has been analytically determined by means of multiple settling velocity formulas proposed by various authors and eventually compared to experimental data. Results deriving from the adoption of each single settling velocity formula have been extensively analysed, showing fairly different outcomes.

РОЛЬ ФИЗИЧЕСКОЙ РАЗМИНКИ В ПОДГОТОВКЕ К ТРЕНИРОВОЧНЫМ ЗАНЯТИЯМ И СОРЕВНОВАНИЯМ ШАХМАТИСТОВ БГУ

2019 ◽  
pp. 63-65
Author(s):  
Судоргин Е.П. ◽  
Карсакова И.Н.
Keyword(s):  
Experimental Data ◽  
Sport Performance ◽  
Warm Up ◽  
Physical Exercises ◽  
Methods Of Evaluation ◽  
Mental Fitness ◽  
Physical Preparation ◽  
Tools And Methods

Аннотация: О роли разминки перед тренировкой и соревнованиями написано много научных статьей и диссертаций. Ещё больше о значимости физической подготовки спортсменов, в том числе и шахматистов. В то же время авторы считают, что вопросу физической подготовки шахматистов и в частности разминке в научной и научно-методической литературе уделяется недостаточно внимания. В своей статье авторы приводят собственные экспериментальные данные о влиянии физических упражнений (разминки) на умственную работоспособность студентов-шахматистов БГУ и как следствие на спортивные результаты команды. Ключевые слова: Шахматы, разминка, умственная работоспособность, средства и методы разминки, методы оценки результатов. Аннотация: Машыгуунун жана мелдештердин алдында даярдоонун ролу жөнүндө көптөгөн илимий макала жана диссертация жазылган. Ошондой эле илимий жана илимий-методикалык адабияттарда шахматка даярдоого көп көңүл бурулбай жатат. Макаланын авторлору шахмат ойногон студенттерге физикалык көнүгүүлөрдүн тийгизген таасири жөнүндө өздөрүнүн эксперименталдык маалыматтарын көргөзүштү. Түйүндүү сөздөр: Шахмат, акыл-дарамет, курулуштар жана ыкмалар, баа берүү жыйынтыгы боюнча кабыл алынат. Abstract: on the role of warm-up before training and competitions written many scientific articles and theses. More about the significance of the physical preparation of athletes, including players. At the same time, the authors believe that the issue of fit- ness players and in particular workout in scientific and scientific-methodical literature neglected. In his article the authors cite their own experimental data on the influence of physical exercises (warm-up) on the mental fitness of students-BSU players and as a result the sport performance team. Keywords: chess, warm-up, mental fitness, workout tools and methods, methods of evaluation results.

Private Capital Participation: Choices and Constraints

1992 ◽  
Vol 26 (7-8) ◽  
pp. 1915-1920
Author(s):  
D. Kinnersley
Keyword(s):  
Wastewater Treatment ◽  
Pollution Control ◽  
Private Capital ◽  
Role Of Government ◽  
Policy Choices ◽  
Government Role ◽  
Private Participation ◽  
The Government ◽  
Participation Frameworks

The scope for involving private capital participation in wastewater treatment and pollution control is attracting attention in a number of countries. After noting briefly some influences giving rise to this trend, this paper discusses frameworks in which such participation may be developed. In some aspects, there are choices available and it is essential to shape the private participation appropriately to the community's situation and problems, with due recognition of the hazards also involved. In other aspects, policy choices are more constrained, and there are requirements which it is suggested all private participation frameworks should provide for as clearly as possible. Effective private participation generally depends on re-designing and strengthening the role of government as the scale of its former role is reduced. Getting this re-design of the government role right is at least as important as making appropriate choices for format of private participation.

scholarly journals Oxidation of Terpenoids to Achieve High-Value Flavor and Fragrances—Questioning Microalgae Oxidative Capabilities in the Biotransformation of the Sesquiterpene Valencene and of Selected Natural Apocarotenoids

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 821-830
Author(s):  
Davide De Simeis ◽  
Stefano Serra ◽  
Alessandro Di Fonzo ◽  
Francesco Secundo
Keyword(s):  
Experimental Data ◽  
Natural Products ◽  
Aqueous Medium ◽  
Photochemical Reaction ◽  
Substrate Oxidation ◽  
Market Size ◽  
Chlorella Sp ◽  
General Opinion ◽  
Natural Way

Natural flavor and fragrance market size is expected to grow steadily due to the rising consumer demand of natural ingredients. This market request is guided by the general opinion that the production of natural compounds leads to a reduction of pollution, with inherent advantages for the environment and people’s health. The biotransformation reactions have gained high relevance in the production of natural products. In this context, few pieces of research have described the role of microalgae in the oxidation of terpenoids. In this present study, we questioned the role of microalgal based oxidation in the synthesis of high-value flavors and fragrances. This study investigated the role of three different microalgae strains, Chlorella sp. (211.8b and 211.8p) and Chlorococcum sp. (JB3), in the oxidation of different terpenoid substrates: α-ionone, β-ionone, theaspirane and valencene. Unfortunately, the experimental data showed that the microalgal strains used are not responsible for the substrate oxidation. In fact, our experiments demonstrate that the transformation of the four starting compounds is a photochemical reaction that involves the oxygen as oxidant. Even though these findings cast a shadow on the use of these microorganisms for an industrial purpose, they open a new possible strategy to easily obtain nootkatone in a natural way by just using an aqueous medium, oxygen and light.

scholarly journals Deep learning-based morphology classification of activated sludge flocs in wastewater treatment plants

2021 ◽  
Author(s):  
Hisashi Satoh ◽  
Yukari Kashimoto ◽  
Naoki Takahashi ◽  
Takashi Tsujimura
Keyword(s):  
Wastewater Treatment ◽  
Deep Learning ◽  
Activated Sludge ◽  
Morphological Change ◽  
Wastewater Treatment Plants ◽  
Filamentous Bacteria ◽  
Sludge Flocs

A deep learning-based two-label classifier 1 recognized a 20% morphological change in the activated flocs. Classifier-2 quantitatively recognized an abundance of filamentous bacteria in activated flocs.

Study of Advanced Technologies of METs for Herbicides Wastewater Treatment with High Salinity

2013 ◽  
Vol 777 ◽  
pp. 326-329
Author(s):  
Tao Li Song ◽  
Xue Nong Yi ◽  
Zhi Qing Li ◽  
Xin Jin
Keyword(s):  
Wastewater Treatment ◽  
High Salinity ◽  
Removal Rate ◽  
Advanced Technologies

Experiments were conducted to study the role of enhanced micro-electrolysis techniques (METs) in treatment of s-atrazine wastewater, regarding atrazine production wastewater as the object of this research. The intensified METs methods included O3and ultrasound (US). With O3METs technology, a better result could be achieved under weak acidity condition. The highest removal rate of TOC reached 18.7%. US before METs could gain higher removal rate of 38.7% compared to the rate of 27.8% by US in METs.

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