activated sludge system Articles

  • What are the parameters of an extended-aeration activated-sludge system?

    The activated sludge process is the most widely used biological water and wastewater treatment. As is well known, by its means, suspended-growth microorganisms are applied to breakdown wastes. Aeration, the mixing of air and a liquid, is the means used to speed the reactions involved. Aeration methods include spraying the liquid into the air; diffusing air into the liquid or agitating the liquid ...

  • 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

  • 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 ...

  • 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 ...

  • 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

  • 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

  • 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

  • Abattoir, commissioning of activated sludge plant case study

    This abattoir’s ancient activated sludge system needed complete refurbishment requiring the aeration tank to be drained. A characteristic of the waste water is its consistently very high ammonia concentration. The activated sludge system has to achieve a final effluent of 20 mg/l BOD, 10 mg/l ammonia and 30 mg/l suspended solids. The authorities required that this standard be ...


    By Bio Systems Europe

  • 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

  • Modeling organic nitrogen conversions in activated sludge bioreactors

    For biological nutrient removal (BNR) systems designed to maximize nitrogen removal, the effluent total nitrogen (TN) concentration may range from 2.0 to 4.0 g N/m3 with about 25–50% in the form of organic nitrogen (ON). In this study, current approaches to modeling organic N conversions (separate processes vs. constant contents of organic fractions) were compared. A new conceptual model of ON ...


    By IWA Publishing

  • OUR Set-Point Control of Activated Sludge Processes

    The OUR Set-Point method is useful for controlling the activity and loading-rate capacity of an activated sludge mixed liquor. In this case, sufficient amounts of a stock substrate are added to a mixed liquor suspension to provide kinetic saturation with subsequent measure of OUR. Once an acceptable substrate is found for a specific wastewater treatment plant, an OUR can be identified that ...


    By Challenge Technology

  • White Paper: Cyclical Aeration Control- Combining Aerobic & Anoxic Conditions in One Basin

    Increase Water Quality with Cyclical Aeration With increased effluent pollution restrictions on municipal wastewater treatment plants, cities are pressed to find ways to economically increase their effluent quality with little to no funding. Many new NPDES permits ...

  • 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

  • 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 virus ...


    By IWA Publishing

  • Proteomics reliability for micropollutants degradation insight into activated sludge systems

    Little information is available on pharmaceutical trace compounds degradation pathways in wastewater. The potential of the proteomics approach has been evaluated to extract information on activated sludge microbial metabolism in degrading a trace concentration of a pharmaceutical compound (ibuprofen). Ibuprofen is one of the most consumed pharmaceuticals, measured in wastewater at very high ...


    By IWA Publishing

  • 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

  • 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 ...

  • 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

  • Seven Ways Your Facility Isn’t Meeting Effluent Regulations and How to Solve Them

    Whether you own, operate, or help manage a municipal or industrial facility that deals with wastewater, it’s important to understand how wastewater treatment can play a significant role in the overall health of your business, especially when it comes to meeting effluent regulations. This is an important part of the wastewater treatment process to consider, as ignoring it could earn your ...


    By SAMCO Technologies, Inc.

  • Investigating Steam Application for Reducing Foaming in Activated Sludge Systems

    Filamentous foam, the dispersion of gas bubbles that creates a dense brown scum layer on the surface of activated sludge basins and secondary clarifiers, is caused by the predominance of mycolic acid-containing actinomycetes, such as Gordonia amarae (formerly Nocardia amarae) and the filament Microthrix parvicella. The accumulation of foam causes a variety of operational, safety, and aesthetic ...

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