Increased performance of secondary clarifiers using dynamic distribution of minimum return sludge rates

2009 ◽  
Vol 60 (9) ◽  
pp. 2439-2445 ◽  
Author(s):  
A. Lynggaard-Jensen ◽  
P. Andreasen ◽  
F. Husum ◽  
M. Nygaard ◽  
J. Kaltoft ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Suspended Solids ◽  
Considerable Increase ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Total Flow ◽  
Equal Distribution ◽  
Solids Concentration ◽  
Hydraulic Load ◽  
And Control

Most wastewater treatment plants have several secondary clarifiers or even more sets of clarifiers including several secondary clarifiers, and in practice it is a well known problem that equal distribution of the load to the single clarifier (or set of clarifiers) is very difficult—not to say impossible—to obtain. If the problem is neglected, quite a big percentage of the total clarifier capacity—measured as the max. allowed hydraulic load—can be lost. Further, return sludge rates are seldom controlled by any other means than as a (typically too high) percentage of the inlet to the wastewater treatment plant—giving a varying and too low suspended solids concentration in the return sludge, which again can lead to an unnecessary use of polymer in the pre-dewatering of the surplus sludge taken from the return sludge. A control of the return sludge rate divided into two parts - control of the total return sludge flow and control of how the total flow shall be distributed between the secondary clarifiers - is able to solve the mentioned problems. Finally, as shall be demonstrated on full scale wastewater treatment plants, a considerable increase of the hydraulic capacity of the treatment plants can be obtained.

Performance of activated sludge diffusion for biological treatment of hydrogen sulphide gas emissions

2013 ◽  
Vol 68 (9) ◽  
pp. 1932-1939 ◽  
Author(s):  
Vera L. Barbosa ◽  
Richard M. Stuetz
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Hydrogen Sulphide ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Broad Application ◽  
H2s Removal ◽  
Treatment Performance ◽  
Solids Concentration

Odours from wastewater treatment plants are comprised of a mixture of various gases with hydrogen sulphide (H2S) often being the dominant constituent. Activated sludge diffusion (ASD) as a biotreatment system for odour abatement has been conducted for over 30 years but has limited broad application due to disagreement in the literature regarding the effect that ASD may have on wastewater treatment performance. The effects of continuous H2S diffusion at 25 ppmv, with weekly peaks of approximately 100 ppmv, on H2S removal efficiency and wastewater treatment performance was evaluated over a 2-month period using an activated sludge pilot plant. H2S removal averaged 100% during diffusion at 25 ppmv, and 98.9% during the 100 ppmv peak periods. A significant increase in mixed liquor volatile suspended solids concentration (P < 0.01) was observed during H2S diffusion, which may be due to an increase in H2S-degrading microorganisms. There was no adverse effect of H2S on nitrification throughout the ASD trials. Ammonia (NH3) removal was slightly better in the test receiving H2S diffusion (87.6%) than in the control (85.4%). H2S diffusion appeared to improve robustness of the AS biomass to operational upsets.

scholarly journals Reliability of removal of selected pollutants in different technological solutions of household wastewater treatment plants

2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Total Suspended Solids ◽  
Hybrid Reactor ◽  
Limit Values

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.

Modelling of the Secondary Clarifier Combined with the Activated Sludge Model No. 1

1992 ◽  
Vol 25 (6) ◽  
pp. 285-300 ◽  
Author(s):  
René Dupont ◽  
Mogens Henze
Keyword(s):  
Wastewater Treatment ◽  
Simple Model ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Activated Sludge Model ◽  
Effluent Quality ◽  
Secondary Clarifier ◽  
Hydraulic Load ◽  
Flux Model

Modelling of activated sludge wastewater treatment plants is today generally based on the Activated Sludge Model No. 1 combined with a very simple model for the secondary settler. This paper describes the development of a model for the secondary clarifier based on the general flux theory for zone settling, which can be used in combination with the Activated Sludge Model to form a dynamic computer model/program for a wastewater treatment plant. In addition to the flux model, the developed model includes a simple model for predicting the contents of paniculate components in the effluent This latter model is a purely empirical model, which connects the effluent quality with the hydraulic load, suspended solids load and the nitrate load. The paper describes the model and gives some basic examples on computer simulations and verification of the model.

An integrated system to remote monitor and control anaerobic wastewater treatment plants through the internet

2005 ◽  
Vol 52 (1-2) ◽  
pp. 457-464 ◽  
Author(s):  
O. Bernard ◽  
B. Chachuat ◽  
A. Hélias ◽  
B. Le Dantec ◽  
B. Sialve ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Integrated System ◽  
The Internet ◽  
Anaerobic Wastewater Treatment ◽  
Control Centre ◽  
Automatic Controllers ◽  
New Sensors ◽  
And Control

The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem.

Particle size analysis as a tool for performance measurements in high rate effluent filtration

2001 ◽  
Vol 43 (10) ◽  
pp. 303-311 ◽  
Author(s):  
J. H. J. M. van der Graaf ◽  
J. de Koning ◽  
J. Tang
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Membrane Filtration ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Size Analysis ◽  
Particle Removal ◽  
Deep Bed Filtration ◽  
Filter Performance

In the Netherlands almost all wastewater treatment plants have been redesigned and adapted in order to remove nitrogen, phosphorus and suspended solids to a very low level. The improved effluent quality leads to a growing interest in the reuse of effluent of the modernised wastewater treatment plants. This again results in investigations on filtration techniques as deep bed filtration and membrane filtration. At the wastewater treatment plant Ede research was done on deep bed filtration in order to develop relations between particle removal and filter performance and to explore ways of optimization. The results of the experiments are rather typical for effluent of modern Dutch wastewater treatment plants. The very low concentrations of suspended solids and precipitable substances result in poor flocculating properties. From turbidity measurements it may be concluded that the best results were obtained with a dosage of flocculant. However, the particle size measurements indicated the opposite. Suspended solids calculations, based on the particle volume distributions, showed a better removal without a dosage of flocculant. From this it is concluded that a dosage of coagulant (Fe3+ or Al3+) has an adverse effect on the removal efficiencies even at low dosages (1 mg/l).

scholarly journals Opportunities for microbial electrochemistry in municipal wastewater treatment – an overview

2014 ◽  
Vol 69 (7) ◽  
pp. 1359-1372 ◽  
Author(s):  
Oskar Modin ◽  
David J. I. Gustavsson
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Energy Content ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes ◽  
Municipal Wastewater Treatment Plants ◽  
And Control ◽  
The Impact

Microbial bioelectrochemical systems (BESs) utilize living microorganisms to drive oxidation and reduction reactions at solid electrodes. BESs could potentially be used at municipal wastewater treatment plants (WWTPs) to recover the energy content of organic matter, to produce chemicals useful at the site, or to monitor and control biological treatment processes. In this paper, we review bioelectrochemical technologies that could be applied for municipal wastewater treatment. Sjölunda WWTP in Malmö, Sweden, is used as an example to illustrate how the different technologies potentially could be integrated into an existing treatment plant and the impact they could have on the plant's utilization of energy and chemicals.

Tracking influent inorganic suspended solids through wastewater treatment plants

2006 ◽  
Vol 54 (8) ◽  
pp. 101-109 ◽  
Author(s):  
G.A. Ekama ◽  
M.C. Wentzel ◽  
S.W. Sötemann
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Settling Tank ◽  
Treatment Plant ◽  
Primary Sludge ◽  
Unit Operations ◽  
Sludge Digestion ◽  
N Removal

From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) and anaerobic and aerobic sludge digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through primary sludge anaerobic digestion, activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant (WWTP) unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organisms (OHO) biomass contributes to the ISS flux by differing amounts depending on the active fraction of the VSS solids at that stage.

scholarly journals Resource-building structures hydraulic account for treatment of vehicle washing stations wastewater

2021 ◽  
Vol 264 ◽  
pp. 03013
Author(s):  
Aybek Arifjanov ◽  
Uchqun Umarov ◽  
Akmal Abdullayev
Keyword(s):  
Wastewater Treatment ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Local Treatment ◽  
Settling Tank ◽  
Treatment Plant ◽  
Petroleum Products ◽  
Hydraulic Calculation ◽  
Design Parameters ◽  
Building Structures

The article presents a method for calculating the parameters of treatment facilities to bring the level of precipitation and wastewater from small enterprises, shops, and services of the Republic to the level of sewage and irrigation trays. The aim is to improve the design parameters of resource-efficient wastewater treatment plants and their widespread use, increase the production capacity of local wastewater treatment plants, improve the level of wastewater treatment and prevent environmental degradation. Hydraulic calculation of the design parameters of the settling tank was carried out at the local treatment plant. The precipitator works by precipitating suspended solids and separating petroleum products from the liquid surface. At the local treatment plant, the content of petroleum products in industrial and precipitation effluents was reduced to 3 mg/l, and the number of suspended solids to 1-1.5 mg/l.

Operational and control practices to improve the performance of small wastewater treatment plants in Catalonia

2000 ◽  
Vol 41 (1) ◽  
pp. 53-56 ◽  
Author(s):  
C. Camos ◽  
S. Martorell ◽  
A. Rey ◽  
D. Güell ◽  
J. Robusté ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Solids Separation ◽  
And Control ◽  
Separation Problems

Observations during routine wastewater treatment plants (WWTP) controls in Catalonia suggest that in small Activated Sludge (AS) plants suspended solids separation problems could reach a special intensity. In order to evaluate their incidence, filamentous scums, clarifier floating solids, rising sludge, deflocculation and bulking incidences occurring in 34 small WWTP were controlled for a year. To improve the efficiency of these plants, analyses of mainly suspended solids separation problems were systematically performed.

scholarly journals The use of pulsed flushing to improve the efficiency of polymer floating media filters

2019 ◽  
Vol 100 ◽  
pp. 00022
Author(s):  
Zhanna Govorova ◽  
Alexey Andrianov
Keyword(s):  
Wastewater Treatment ◽  
Surface Runoff ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Oil Products ◽  
Operational Parameters ◽  
Mineral Salts ◽  
Runoff Water ◽  
Mechanical Removal

Surface runoff from urban area is a potential source of pollution of water bodies. The composition of pollutants in surface runoff depends on various factors and seasons. The main pollutants are oil products, suspended solids, COD, chlorides and other mineral salts. Traditional wastewater treatment plants include the mechanical removal of large items, debris and leaves; sand removal; water clarification in accumulating settling tanks; chemical dosing, contact filtration and deep purification on sorption filters. Filters with inert floating polystyrene media of various types are widely used as first stage filters. The operation of industrial filters in the technological schemes of wastewater treatment strongly depends on the backwash efficiency. Floating media flushing is carried out in the direction from top to down using the water accumulated in the over-filter space. The article presents the results of the study of pulsed flushing on a model plant. Experimental study was conducted on the real wastewater treatment plant. The kinetics of suspended solids and oil products removal from filter media was studied. The operational parameters and mode of pulsed flushing were determined. The research results were used during the reconstruction of Moscow surface runoff water treatment plants.

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