activated sludge Articles

  • 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 ...


    By Water Experts Germany

  • Ultrasonic irradiation of activated industrial sludge

    Sludge is a by-product of wastewater treatment and contains multitude of pollutants. In the present study, irradiation with ultrasound as treatment technique was carried out to treat complex effluent paper sludge, sugar sludge and sewage sludge samples from different industrial places. Wastewater samples were treated in ultrasonic bath at 25 kHz for different time periods of 5 min, 10 min, 20 min ...


    By Inderscience Publishers

  • Guidelines for using activated sludge models

    Mathematical modelling of activated sludge systems is used widely for plant design, optimisation, training, controller design and research. The quality of simulation studies varies depending on the project objectives, finances and expertise available. Consideration has to be given to the model accuracy and the amount of time required carrying out a simulation study to produce the desired ...


    By IWA Publishing

  • Effect of sludge age on heavy metal biosorption by selector activated sludge

    The influence of sludge age on the metal biosorption characteristics of an aerobic selector-activated sludge was investigated. Two bench-scale aerobic-activated sludge systems were operated at sludge ages of 5 days and 15 days for studying biosorption of Cu and Cr(VI). In-vitro batch experiments were performed to compare biosorption characteristics of the sludge samples harvested from the ...


    By Inderscience Publishers

  • Influence of microbial activity on polar xenobiotic degradation in activated sludge systems

    Publisher's note. We very much regret that in production certain errors were introduced into the above article. We wish to apologise to authors and readers for these errors and any confusion that may have been caused: the corrections are given ...


    By IWA Publishing

  • Low intensity ultrasound stimulates biological activity of aerobic activated sludge

    This work aims to explore a procedure to improve biological wastewater treatment efficiency using low intensity ultrasound. The aerobic activated sludge from a municipal wastewater treatment plant was used as the experimental material. 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 ...


    By Springer

  • The role and control of sludge age in biological nutrient removal activated sludge systems

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor ...


    By IWA Publishing

  • A Redefinition of the Role of Microorganisms in Bioaggregation in Activated Sludge

    ABSTRACT Aggregation of microorganisms is considered an important trait crucial to their ecological success and has significant implications for biological wastewater treatment. It has been thought that floc formation in such systems is primarily mediated by floc-forming bacteria, whereas other organisms do not really contribute to flocculation. This hypothesis was tested here by a ...

  • The Role of Activated Sludge Solids in an Actiflo® System

    ABSTRACTThis research was conducted using jar tests to investigate the impact of adding activated sludge solids to the Actiflo® process, a high-rate clarification (HRC) system, to increase BOD removal in HRC systems treating raw wastewater during periods of high wet-weather flows (WWF). A study of dosages and impacts of ferric sulfate, polymer, microsand and activated sludge on performance of the ...

  • Biodegradation of Cypermethrin by pseudomonas in a batch activated sludge process

    The biodegradation of Cypermethrin (20 to 125 mg/L) in an effluent using batch activated sludge was studied. Degradation was found to occur to a great extent only in the presence of Pseudomonas (IES-Ps-1) culture. Under aerobic conditions using mechanical aerators, Cypermethrin (20 mg/L) was almost completely degraded in just over 48 h at ambient temperature. Further loading of organic compound ...

  • Multicomponent activated sludge model for reactors in series with recycling

    Multicomponent models containing both substrate and biomass have an advantage over conventional models in seeking better understanding of activated sludge systems. Such models are also useful in the characterisation of wastewater. Studies in recent years have shown that most of the soluble organic matter in the effluent of treatment systems consists of soluble microbial products that arise during ...


    By Inderscience Publishers

  • Ozonation of endogenous residue and active biomass from a synthetic activated sludge

    Coupling the activated sludge and the ozonation processes is an efficient, although expensive, solution for sludge reduction. A better knowledge of the mechanisms involved in the degradation of various sludge fractions by ozone is needed to optimize the coupled process. The objectives of this study were to determine the biodegradability of ozone-solubilized endogenous residue, the action of ozone ...


    By IWA Publishing

  • Complete solids retention activated sludge process

    In a slaughterhouse's full-scale extended aeration activated sludge wastewater treatment plant (WWTP), operating under complete solids retention time, the evolution of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) concentration, food to micro-organisms ratio (F/M) and substrate utilization rate (SUR) were studied for over a year. Biomass growth phases ...


    By IWA Publishing

  • The Removal of Alkylphenol Ethoxylate Surfactants in Activated Sludge Systems

    US EPA has finalized federal Water Quality Criteria for nonylphenol, a biodegradation intermediate of nonylphenol ethoxylates, which are commonly used surfactants. To provide information in support of this initiative, an assessment was made of the ability of wastewater treatment plants to remove these and other alkylphenol ethoxylate (APEO) surfactants that are used widely in domestic and ...

  • The Dangers of Uncalibrated Activated Sludge Simulation Packages

    ABSTRACTActivated sludge simulation packages are useful tools, but it can be dangerous to rely on them ifthey are used incorrectly. How dangerous? To determine potential pitfalls, we compared theactivated sludge tank volumes predicted by three simulation packages used directly out-of-theboxwithout calibration. We sought to identify the underlying reason for differences in predictedrequired ...

  • 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 ...


    By Inderscience Publishers

  • Membrane fouling mitigation by activated carbon addition in activated sludge filtration

    Activated carbon (AC) was added into the activated sludge to alleviate membrane fouling during sludge microfiltration. The fouling mitigation profiles were evaluated at different AC sizes and doses by a single-fibre microfiltration system. It was found that the granular AC added in the sludge suspension can absorb the organic substances in the sludge in a certain level, including biopolymer ...


    By Inderscience Publishers

  • Application of nitrifying granules to improvement of nitrification activity in activated sludge process

    Nitrifying granules were used to improve nitrification performance of activated sludge process under high organic load. After inoculation of nitrifying granules, nitrification activity immediately increased, and kept for at least 70 days. Fluorescence in situ hybridisation analysis confirmed that nitrifying bacteria were retained in the granules even though nitrifying granules had been served in ...


    By Inderscience Publishers

  • CH#824 - Steel Production - Activated Sludge

    BackgroundThe treatment plant at this Steel Mill treats approximately 0.3mgd waste from the coke and steel operations. Over the past year the treatment works improved performance and consistently produced a good quality effluent with respect to phenol, suspended solids, ammonia and cyanide. An improvement in performance was required to meet future discharge limits. To achieve this level of ...


    By Bio-Systems International

  • 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 ...


    By IWA Publishing

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