scholarly journals Characterization of Filamentous Flocs to Predict Sedimentation Parameters Using Image Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
M. A. Molina ◽  
Claudio Abraham Acuña Pérez ◽  
C. A. Leiva

In wastewater treatment plants, the degradation of complex substances that contaminate water is carried out by microorganisms, which are fixed by a network formed by filamentous bacteria, creating large flocs that settle easily. However, the excessive growth of said bacteria causes a series of drawbacks such as the reduction of settling velocity, leakage of activated sludge with the effluent, and formation of supernatant, a phenomenon known as bulking. This research work seeks to develop and evaluate a procedure for the physical characterization of the flocs to determine the parameters that affect the settling velocity and thereby detect and control bulking. For this purpose, sedimentation and image analysis tests were carried out from wastewater from the Aguas Antofagasta treatment plant (Chile). The image analysis was performed with images captured from an optical microscope in two magnifications (100x and 50x), which were analyzed by marking each floc individually and characterized by an image processing software. Additionally, sedimentation tests were performed on columns (area of 74 (cm2) and height of 70 (cm)). As a result, an inversely proportional dependence was found on the settling velocity evaluated by the Vesilind equation in the zone of constant fall velocity with respect to the number of flocs connected per cluster, giving an estimate of the settling velocity depending on the number of flocs connected. This would allow predicting settling velocity with image analysis, taking into account that the problem of bulking is determined by the type of filamentous bacteria that causes it and the sedimentation process is affected in large part by local factors. It can be concluded through this study that as the number of flocs connected per cluster increases, the settling velocity decreases. This study provides wastewater treatment plants with a practical tool to determine sedimentation times and thus improve the quality of the treated water, avoiding problems of flocs leaking with the effluent. In addition, the image analysis itself allows rapid detection of the phenomenon of bulking and its severity.

2002 ◽  
Vol 46 (1-2) ◽  
pp. 363-369 ◽  
Author(s):  
M. da Motta ◽  
M.N. Pons ◽  
N. Roche

An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor the biomass in a pilot wastewater treatment plant during two runs inoculated with a different sludge and operated at two different temperatures. The bulking events were easily detected by image analysis. Correlations were found between settleability properties (Sludge Volume Index and settling velocity) and the morphological parameters (filament total length, filament number and floc size).


2020 ◽  
Vol 82 (11) ◽  
pp. 2482-2490
Author(s):  
M. Hanková ◽  
K. Maturová ◽  
H. Čížková

Abstract The foul odour of cheese-production wastewater is a common problem in areas surrounding dairy wastewater treatment plants. For successful odour management, a better understanding of the key odorants and how to handle them during wastewater treatment is needed. This paper documents the results of using gas chromatography-mass spectrometry coupled with olfactometry (GC-MS/O) to analyze odours emanating from a possibly overloaded treatment plant in Czechia. Using a DB5 capillary column, 20 compounds were detected and identified, nonanal (FDgeomean 152) and octen-3-ol (FDgeomean 2048) having the most pungent odours.


2009 ◽  
Vol 59 (8) ◽  
pp. 1603-1609 ◽  
Author(s):  
T. Zarra ◽  
V. Naddeo ◽  
V. Belgiorno ◽  
M. Reiser ◽  
M. Kranert

Odour emissions are a major environmental issue in wastewater treatment plants and are considered to be the main cause of disturbance noticed by the exposed population. Odour measurement is carried out using analytical or sensorial methods. Sensorial analysis, being assigned to the “human sensor”, is the cause of a considerable uncertainty. In this study a correlation between analytical and sensorial methods was investigated. A novel tool was used to both define odour indexes and characterise the odour sources and the volatile substances that cause annoyance in a wastewater treatment plant, with the aim to remove the subjective component in the measure of the odours and define the induced impact. The sources and the main chemical substances responsible for the olfactory annoyances were identified. Around 36 different substances were detected, with more than half being smell relevant components as well as responsible. Dimethyl disulphide was identified as key compound. Results highlight the applicability of highly correlation between analytical and sensorial methods in odour emission monitoring.


2004 ◽  
Vol 50 (3) ◽  
pp. 29-37 ◽  
Author(s):  
E. Fourest ◽  
D. Craperi ◽  
C. Deschamps-Roupert ◽  
J.-L. Pisicchio ◽  
G. Lenon

The occurrence of filamentous bacteria was investigated in 15 French pulp and paper activated sludge wastewater treatment plant (WWTP). Large filamentous populations were present in most of the plants. Identification carried out with conventional methods based on morphological features and staining techniques showed that the four main filamentous bacteria encountered in these industrial WWTP and responsible for bulking belong to the genera Thiothrix sp., Type 021N, Haliscomenobacter hydrossis and Type 0092. During two years a specific survey was performed for three of these WWTP showing recurrent bulking phenomena. Data from WWTP performance, chemical data and filaments characterization were compared to correlate the presence of specific filaments with process operating conditions.


2001 ◽  
Vol 43 (7) ◽  
pp. 91-96 ◽  
Author(s):  
M. da Motta ◽  
M. N. Pons ◽  
N. Roche

An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor the biomass in a pilot wastewater treatment plant, in complement to the usual settleability (sludge volume index, settling velocity) and size distribution (by laser granulometry) measurements.


Pathogens ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Keita Yanagimoto ◽  
Takaya Yamagami ◽  
Kosei Uematsu ◽  
Eiji Haramoto

Salmonella enterica is a major cause of gastroenteritis usually caused by animal-based contaminated foods. Since the current passive surveillance is not sufficient to detect all infections and infection sources, we determined the prevalence of Salmonella isolated from sewage influent of wastewater treatment plants (WWTPs) and compared the characteristics of human and food isolates to identify the infection sources. Sewage influent samples were collected monthly from two WWTPs located in the Yamanashi Prefecture, Japan, for three years. Serotypes, antimicrobial resistances, isolation periods, isolated areas, and pulsed-field gel electrophoresis patterns of six isolates belonging to five serotypes were consistent with those of the isolates from patients. Real-time PCR for Salmonella indicated that sewage influents reflect cases of patients infected with Salmonella, including unreported cases. Serovars Schwarzengrund and Anatum were predominant in sewage, but not in humans, and their characteristics were closely related or identical to those isolated from poultry heart and liver, respectively. These results suggest that sewage influent contains Salmonella isolates from humans and that some originated from unreported human cases infected by poultry-associated products. Therefore, it is necessary to take countermeasures against Salmonella infection based on the unreported cases, which would be disclosed by analysis of sewage influent.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).


1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.


1994 ◽  
Vol 29 (12) ◽  
pp. 255-266 ◽  
Author(s):  
T. Gschlößl

UV-irradiation as an effective method of diminishing germs in the outlet of wastewater treatment plants was studied in a half-scale pilot-project sponsored by the State of Bavaria/BRD for a period of 3 years. Technical, physical and biological parameters capable of influencing this process were examined. The possibility to improve the hygienic and also the ecological structure of receiving waters was put to discussion. Possible effects of formed bypproducts upon the water biocoenosis of rivers were pointed out. The results demonstrated that UV-irradiation can diminish the number of germs in the outlet of a treatment plant to an extent which is sufficient to guarantee the maintenance of the bacteriological and presumably also the virological values set by the EC Bathing Water Directive. Nevertheless the UV-treatment process requires further technological development and research work concerning i.e. the improvement of hydraulic conditions, coat-forming on the quartz sleeves of the lamps, photochemical forming of by-products, after-growth and effects upon the localised benthic flora and fauna of the receiving water. It has to be stressed that a significant improvement of the bacteriological structure of flowing waters is only attainable, if the influx from non-point sources can be reduced simultaneously.


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