activated sludge Articles
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Cyclic activated sludge technology
Cyclic activated sludge technology was selected for the Potsdam Wastewater Treatment Plant (90,000 p.e.). The cyclic activated sludge facility comprises four modules integrated into two circular basins. Construction was commenced in February 1998 with seeding of the plant for start up taking place in October 1998. Process performance has been met since Spring 1999 at 80-90 percent of design load. ...
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The use of rotifers for limiting filamentous bacteria Type 021N, a bacteria causing activated sludge bulking
The excessive growth of filamentous bacteria and the resultant bulking of activated sludge constitute a serious problem in numerous wastewater treatment plants. Lecane inermis rotifers were previously shown to be capable of reducing the abundance of Microthrix parvicella and Nostocoida limicola in activated sludge. In the present study, the effectiveness of four Lecane clones in reducing the ...
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Rapid quantification of polyhydroxyalkanoates (PHA) concentration in activated sludge with the fluorescent dye Nile blue A
The present study was conducted (1) to develop a rapid quantification method of polyhydroxyalkanoates (PHA) concentration in activated sludge by Nile blue A staining and fluorescence measurement and (2) to perform on-line monitoring of PHA concentrations in activated sludge. Activated sludge samples collected from laboratory scale sequencing batch reactors and full-scale wastewater treatment ...
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Twenty-five years of ASM1: past, present and future of wastewater treatment modelling
Activated sludge systems have been applied for 100 years now. Over the course of the years, researchers have developed various models to describe activated sludge processes. The main aim has been to gain a better understanding of the conditions that favour the conversions of carbon, nitrogen and phosphorus present in wastewater, and associated oxygen consumption and sludge production. The ...
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Applications of the deep-shaft activated sludge process in wastewater treatment
The deep-shaft activated sludge process is a unique modification of the activated sludge system. The main objective of this system is to increase the amount of dissolved oxygen available for biological activity. This can be achieved by increasing the rate of oxygen transfer from the gas phase to the liquid phase. The deep-shaft configuration increases the partial pressure of oxygen, thereby ...
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Activated Sludge Types for Sewage & Water Treatment
Activated Sludge Types for Sewage & Water TreatmentIn the Activated Sludge Process for waste water treatment, microorganisms, including bacteria, fungi, and protozoa, are used to speed up the decomposition of organic matter requiring oxygen for treatment.The Activated Sludge name and meaning originates from the process it involves: the production of an activated mass of microorganisms capable ...
By YASA ET
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Bioremoval of colour from textile wastewater by sequencing batch reactor and biotechnological methods
In experimental studies, single growth white rot fungi Phanerochaete chrysosporium has been additionally used to obtain the decolourisation capacity of fungal biomass. It has been shown that average efficiency of classical activated sludge in SBR reaches 71% during 1600 mins for 436, 525 and 620 nm absorbance. It has been shown that average efficiency of advanced activated sludge in SBR reaches ...
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Influence of reactor configuration on reliability of activated sludge process
The effect of uncertainty in system parameters and the accuracy of the mathematical model used on the design and reliability of the activated sludge process is investigated by Monte Carlo simulations. Simulations indicate that the coefficient of variation for a reactor volume varies from 0.56 for a single mixed tank reactor to 0.44 for a plug flow reactor. The coefficient of variation for ...
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Improving activated sludge classification based on imbalanced data
A fast and accurate classification method for sewage sludge biological activity classification is of great significance for wastewater treatment. However, the data are often imbalanced and the accuracy of traditional classification algorithms applied to imbalanced small classes of data is very low. Such small classes are crucial application data. Therefore, based on the analysis of eight ...
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Removal characteristics of retinoic acids and 4-oxo-retinoic acids in wastewater by activated sludge treatment
Retinoic acid (RA) receptor (RAR) agonists are potential teratogens to various vertebrates. Their contamination has been detected in municipal wastewater in different countries. This study involved field investigations and laboratory batch treatment experiments to elucidate the removal characteristics by activated sludge treatment of RAs (all-trans RA and 13-cis RA) and 4-oxo-RAs ...
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Effect of high salinity on yeast activated sludge reactor operation
Yeast activated sludge was developed and operated at salinities of 0, 15, 30, 45, and 60 g/l NaCl. The kinetics of the various sludges degrading a wastewater with glycerol as the carbon source were determined. Inhibition due to salinity was analyzed and it was found that the limiting concentration of NaCl is 120 g/l. Salinity affects the maximum growth rate of the sludge. Reactors were ...
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Virus elimination in activated sludge systems: from batch tests to mathematical modeling
A virus tool based on Activated Sludge Model No. 3 for modeling virus elimination in activated sludge systems was developed and calibrated with the results from laboratory-scale batch tests and from measurements in a municipal wastewater treatment plant (WWTP). The somatic coliphages were used as an indicator for human pathogenic enteric viruses. The extended model was used to simulate the ...
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Design of a generalized predictive controller for a biological wastewater treatment plant
This paper presents a generalized predictive control (GPC) technique to regulate the activated sludge process found in a bioreactor used in wastewater treatment. The control strategy can track dissolved oxygen setpoint changes quickly, adapting to the system uncertainties and disturbances. Tests occur on an Activated Sludge Model No. 1 benchmark of an activated sludge process. A T filter ...
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Comparison of imidazolium ionic liquids and traditional organic solvents: effect on activated sludge processes
Data concerning the biodegradability and ecotoxicity of ionic liquids (ILs) obtained so far are insufficient in the context of IL removal from wastewater in activated sludge systems. Thus, in this work the selected imidazolium ionic liquids and two organic solvents (methanol and acetone) were tested with respect to their influence on activated sludge processes, particularly on the morphology of ...
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Genome-scale metabolic modeling to provide insight into the production of storage compounds during feast–famine cycles of activated sludge
Studying storage metabolism during feast–famine cycles of activated sludge treatment systems provides profound insight in terms of both operational issues (e.g., foaming and bulking) and process optimization for the production of value added by-products (e.g., bioplastics). We examined the storage metabolism (including poly-β-hydroxybutyrate [PHB], glycogen, and triacylglycerols ...
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Respirometry study about the olive oil effects in the activated sludge process case study
The problem of Oils in the Activated Sludge Process In many activated sludge plants excessive oils discharges can give rise to Nocardia foaming which causes major operational problems. While the bulk of the oils are removed in Dissolved Air Flotation (DAF) units or grease interceptors the remainder must be treated in the wastewater treatment system. But however, in case of high concentration, ...
By SURCIS, S.L.
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Characteristics of municipal wastewater treatment by moving-bed biofilm reactor
In this paper, the bio-activity of activated sludge was investigated using Oxygen Uptake Rate (OUR) as an indicator. The activity of ammonium oxidation and COD removal of both attached- and suspended-growth sludge was determined under different temperature and organic loading rates. The experimental results indicated that at 5°C, the nitrification activity was about 60% of that at 18°C. The ...
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A pilot-scale study on PVA gel beads based integrated fixed film activated sludge (IFAS) plant for municipal wastewater treatment
In the present study, a pilot-scale reactor incorporating polyvinyl alcohol gel beads as biomass carrier and operating in biological activated sludge mode (a combination of moving bed biofilm reactor (MBBR) and activated sludge) was investigated for the treatment of actual municipal wastewater. The results, during a monitoring period of 4 months, showed effective removal of chemical oxygen ...
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Investigation of OUR and NUR experiments for nitrogen and phosphorus removal with activated sludge: a lab-scale study
Activated sludge systems are widely used in wastewater treatment. Organic carbon removal and nutrient removal are important for stringent water discharge standards. Therefore, activated sludge systems are widely used to remove carbon, nitrogen and phosphorus in new wastewater treatment systems or upgrades of existing systems. The determination of system compounds and kinetic parameters for ...
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Challenges encountered when expanding activated sludge models: a case study based on N2O production
It is common practice in wastewater engineering to extend standard activated sludge models (ASMs) with extra process equations derived from batch experiments. However, such experiments have often been performed under conditions different from the ones normally found in wastewater treatment plants (WWTPs). As a consequence, these experiments might not be representative for full-scale ...
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