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

  • Where To Find Money In Biogas

    On the surface, wastewater treatment operations don’t appear to be handling precious material. But these facilities are actually processing a great deal of value every day. Sludge, a byproduct of wastewater treatment, turns out to be an entity worth cherishing. “Depending on treated sludge quality, the final product can be land applied, landfilled, incinerated, or composed,” ...


    By KLa Systems, Inc.

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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 ...

  • 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 ...

  • 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 ...

  • 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

  • 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

  • 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 ...

  • Biosorption and biodegradation of trichloroethylene by acclimated activated sludge

    The biosorprion and biodegradation of trichloroethylene (TCE) was investigated. The experimental results showed that at 25°C the adsorption equilibrium of TCE at concentrations from 10 mg/L to 200 mg/L could be described by the Freundlich isotherm. Adsorption could complete within 15 min. Results indicated that glucose could serve as a co-substrate and enhance TCE biodegradation through ...


    By Inderscience Publishers

  • Ammonia Stripping And Integrated Fixed-Film Activated Sludge

    The Keystone Sanitary Landfill (KSL) is located at the Keystone Industrial Park in Dunmore and Throop Boroughs, Pennsylvania. The 618 acre landfill site was originally permitted for 5,000 tons of trash per day, and recently received a permit to develop more cells to extend the operation for another 25 years at 5,000 tons per day. Landfill leachate, an inevitable by-product of landfilling, is ...


  • 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

  • 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

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