Sample records for sludge nuernberger abwassertagung

  1. Sludge. (United States)

    Tenenbaum, David


    Cites a recycling success story involving sludge production from wastewater and transformation into an effective plant fertilizer. Discusses related concerns such as dealing with pollutants like heavy metals and PCBs often found in sludge. Provides an example of an application of sludge produced in Chicago to an area reclamation site. (MCO)

  2. The documentation center on the 'Reichsparteitag' terrain at Nuremberg; Dokumentationszentrum Reichsparteitagsgelaende in Nuernberg

    Energy Technology Data Exchange (ETDEWEB)

    Hufer, B.; Wiedmann, E. [Dess-Falk Beratende Ingenieure, Nuernberg (Germany)


    There is hardly another city in Germany that is haunted by its history as much as Nuremberg - not its medieval history as an important trade center but the period of the Hitler and after. This applies to political history as well as to the buildings that remained. For example, there are many unfinished buildings and ruins on the 4 km{sup 2} 'Reichsparteitag' terrain. Since 2001, this terrain houses a documentation centre as a contribution to coming to terms with history. [German] Kaum eine zweite deutsche Stadt ist derart mit ihrer Geschichte verbunden wie Nuernberg. Nicht mit der Bedeutung als freie Reichsstadt im ausgehenden Mittelalter, vielmehr mit den Reichsparteitagen in der Zeit des Nationalsozialismus und den Nuernberger Prozessen muss sie sich bis heute auseinandersetzen. Dies betrifft nicht nur das geistige Erge, sondern auch das staedtebauliche. So finden sich noch heute zahlreiche unvollendete Bauwerke und Ruinen aus dieser Zeit - so auch auf dem ca. 4 km{sup 2} grossen ehemaligen Reichsparteitagsgelaende. Hier leistet seit November 2001 ein Dokumentationszentrum einen Beitrag zur Aufarbeitung der Vergangenheit. (orig.)

  3. Passive house progress report: Energy and indoor air quality. Measuring methods and verification of energy saving potentials and indoor air quality in passive houses at Nuremberg; Passivhaus-Projektbericht: Energie und Raumluftqualitaet. Messetchnische Evaluierung und Verifizierung der energetischen Einsparpotentiale und Raumluftqualitaet an Passivhaeusern in Nuernberg. Projekt: Passiv-Haus-Doppelhaeuser, Wachtelstrasse 12/Praelat-Nicol-Strasse 3-7, Nuernberg-Wetzendorf

    Energy Technology Data Exchange (ETDEWEB)

    Schulze Darup, B. (ed.)


    A model passive building was constructed at Nuremberg. Buildings of this type have an annual heat consumption of less than 15 kWh/m{sup 2}, so that quality assurance is of utmost importance with regard to energy consumption, primary energy balance, environmental impact and especially room air quality. The findings of the project will be published. [German] Im Rahmen der Lokalen Agenda 21 wurde in Nuernberg ein Passivhaus-Modellprojekt erstellt. Da energiesparende Wohngebaeude mit einem jaehrlichen Heizwaermebedarf unter 15 kWh/m{sup 2} zunehmend zum Stand der Technik werden, ist eine grundlegende Qualitaetssicherung hinsichtlich Energieverbrauch, Primaerenergiebilanz, Umweltvertraeglichkeit und insbesondere Raumluftqualitaet sowie die Veroeffentlichung der Erfahrungen von grosser Bedeutung. (orig.)

  4. Biliary sludge. (United States)

    Ko, C W; Sekijima, J H; Lee, S P


    Biliary sludge was first described with the advent of ultrasonography in the 1970s. It is defined as a mixture of particulate matter and bile that occurs when solutes in bile precipitate. Its composition varies, but cholesterol monohydrate crystals, calcium bilirubinate, and other calcium salts are the most common components. The clinical course of biliary sludge varies, and complete resolution, a waxing and waning course, and progression to gallstones are all possible outcomes. Biliary sludge may cause complications, including biliary colic, acute pancreatitis, and acute cholecystitis. Clinical conditions and events associated with the formation of biliary sludge include rapid weight loss, pregnancy, ceftriaxone therapy, octreotide therapy, and bone marrow or solid organ transplantation. Sludge may be diagnosed on ultrasonography or bile microscopy, and the optimal diagnostic method depends on the clinical setting. This paper proposes a protocol for the microscopic diagnosis of sludge. There are no proven methods for the prevention of sludge formation, even in high-risk patients, and patients should not be routinely monitored for the development of sludge. Asymptomatic patients with sludge can be managed expectantly. If patients with sludge develop symptoms or complications, cholecystectomy should be considered as the definitive therapy. Further studies of the pathogenesis, natural history, and clinical associations of biliary sludge will be essential to our understanding of gallstones and other biliary tract abnormalities.

  5. K basins sludge removal sludge pretreatment system

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.L.


    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.

  6. Respirometry in activated sludge

    NARCIS (Netherlands)

    Spanjers, H.


    The purpose of the study was (1) to develop a respiration meter capable of continuously measuring, using different procedures, the oxygen uptake rate of activated sludge and (2) to expand knowledge about respiration related characteristics of wastewater and activated sludge.


  7. Activated Sludge Rheology

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Horn, Willi; Helmus, Frank


    Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtr...

  8. Activated sludge model No. 3

    DEFF Research Database (Denmark)

    Gujer, W.; Henze, M.; Mino, T.


    The Activated Sludge Model No. 3 (ASM3) can predict oxygen consumption, sludge production, nitrification and denitrification of activated sludge systems. It relates to the Activated Sludge Model No. 1 (ASM1) and corrects for some defects of ASM I. In addition to ASM1, ASM3 includes storage...

  9. Sludge treatment studies

    Energy Technology Data Exchange (ETDEWEB)

    Beahm, E.C.; Weber, C.F.; Dillow, T.A.; Bush, S.A.; Lee, S.Y.; Hunt, R.D.


    Solid formation in filtered leachates and wash solutions was seen in five of the six sludges treated by Enhanced Sludge Washing. Solid formation in process solutions takes a variety of forms: very fine particles, larger particulate solids, solids floating in solution like egg whites, gels, crystals, and coatings on sample containers. A gel-like material that formed in a filtered leachate from Enhanced Sludge Washing of Hanford T-104 sludge was identified as natrophosphate, Na{sub 7}(PO{sub 4}){sub 2}F{center_dot}19H{sub 2}O. A particulate material that formed in a filtered caustic leachate from Hanford SX-113 sludge contained sodium and silicon. This could be any of a host of sodium silicates in the NaOH-SiO{sub 2}-H{sub 2}O system. Acidic treatment of Hanford B-202 sludge with 1 M, 3 M, and 6 M HNO{sub 3} sequential leaching resulted in complete dissolution at 75 C, but not at ambient temperature. This treatment resulted in the formation of solids in filtered leachates. Analyses of the solids revealed that a gel material contained silica with some potassium, calcium, iron, and manganese. Two phases were embedded in the gel. One was barium sulfate. The other could not be identified, but it was determined that the only metal it contained was bismuth.

  10. Sludge Stabilization Campaign blend plan

    Energy Technology Data Exchange (ETDEWEB)

    De Vries, M.L.


    This sludge stabilization blend plan documents the material to be processed and the order of processing for the FY95 Sludge Stabilization Campaign. The primary mission of this process is to reduce the inventory of unstable plutonium bearing sludge. The source of the sludge is residual and glovebox floor sweepings from the production of material at the Plutonium Finishing Plant (PFP). The reactive sludge is currently being stored in various gloveboxes at PFP. There are two types of the plutonium bearing material that will be thermally stabilized in the muffle furnace: Plutonium Reclamation Facility (PRF) sludge and Remote Mechanical C (RMC) Line material.

  11. Disposal of domestic sludge and sludge ash on volcanic soils. (United States)

    Escudey, Mauricio; Förster, Juan E; Becerra, Juan P; Quinteros, Magdalena; Torres, Justo; Arancibia, Nicolas; Galindo, Gerardo; Chang, Andrew C


    Column leaching experiments were conducted to test the ability of Chilean volcanic soils in retaining the mineral constituents and metals in sewage sludge and sludge ash that were incorporated into the soils. Small or negligible amounts of the total content of Pb, Fe, Cr, Mn, Cd, and Zn (0 to soils and leached with 12 pore volumes of water over a 3 month period of time, less than 0.1% of the total amount of heavy metals and PO4 in the sludge and sludge ash were collected in the drainage water. Cation exchange selectivity, specific anion adsorption and solubility are the processes that cause the reduction of leaching. The volcanic soils were capable of retaining the mineral constituents, P, and metals in applied sewage sludge and sludge ash and gradually released them as nutrients for plant growth.

  12. K Basins sludge removal temporary sludge storage tank system

    Energy Technology Data Exchange (ETDEWEB)

    Mclean, M.A.


    Shipment of sludge from the K Basins to a disposal site is now targeted for August 2000. The current path forward for sludge disposal is shipment to Tank AW-105 in the Tank Waste Remediation System (TWRS). Significant issues of the feasibility of this path exist primarily due to criticality concerns and the presence of polychlorinated biphenyls (PCBS) in the sludge at levels that trigger regulation under the Toxic Substance Control Act. Introduction of PCBs into the TWRS processes could potentially involve significant design and operational impacts to both the Spent Nuclear Fuel and TWRS projects if technical and regulatory issues related to PCB treatment cannot be satisfactorily resolved. Concerns of meeting the TWRS acceptance criteria have evolved such that new storage tanks for the K Basins sludge may be the best option for storage prior to vitrification of the sludge. A reconunendation for the final disposition of the sludge is scheduled for June 30, 1997. To support this decision process, this project was developed. This project provides a preconceptual design package including preconceptual designs and cost estimates for the temporary sludge storage tanks. Development of cost estimates for the design and construction of sludge storage systems is required to help evaluate a recommendation for the final disposition of the K Basin sludge.

  13. Coagulant Recovery from Waterworks Sludge


    Keeley, James


    Coagulation is a ubiquitous process in the treatment of raw surface water for eventual potable use. Despite its capabilities, the sheer scale of its use is manifested in the volumes of chemicals it demands and waste sludge it produces. Recovering and reusing the chemical activity of the coagulant sludge in water treatment is a logical solution but this practice has been restricted by the presence of contaminants within the sludge. This thesis has investigated methods that ca...

  14. Oily Sludge Biodetoxification (United States)


    bio- contactors , 5 membrane reactors, and activated sludge systems have been developed to maximize bacterial contact with the waste and reduce...with a membrane filter that has enabled them to use all of the treated wastewater for plant cooling. xiv 1 1.0 INTRODUCTION 1.1...other activities. To increase the throughput of the filtration unit, the original membranes were replaced with a polysulfone blend spiral wound

  15. Oily Sludge Biodetoxification (United States)


    Sustainability Development to Integration NAVSTA Naval Station NT not tested O&M operation and maintenance OSHA Occupational Safety and Health ...Safety and Health Administration The results presented here and data from previous pilot scale and prototype (Hawaii) demonstrations of oily sludge...designed to treat. While additional degradation may have occurred if the system was supplemented with micronutrients and operated in series, it is

  16. Improved waste-activated sludge dewatering using sludge/oil ...

    African Journals Online (AJOL)

    Ultrasonication had low dewatering and energy efficiency with long irradiation times, indicating that it would be difficult to implement in a field plant. The water content of sludge was reduced to 60% within 120 s using microwaves, but dewatering efficiency depended on the thickness and volume of the sludge. In a pilot-scale ...

  17. Sludge Digestion Manual; Handboek Slibgisting

    Energy Technology Data Exchange (ETDEWEB)



    This manual offers a guideline for developing, designing, optimizing and operating sludge digestion installations based on sewage sludge. It also offers tools for solving operation problems [Dutch] Het Handboek is een leidraad voor het ontwikkelen, ontwerpen, optimaliseren en bedrijven van slibgistingsinstallaties voor zuiveringsslib. Ook geeft het handvatten voor het oplossen van operationele problemen.

  18. Combatting bulking sludge with ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Wuensch, B.; Heine, W.; Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Dept. of Sanitary and Environmental Engineering


    Bulking and floating sludge cause great problems in many waste water treatment plants with biological nutrient removal. The purification as well as the sludge digestion process can be affected. These problems are due to the interlaced structure of filamentous microorganisms, which have an impact on the sludge's settling behaviour. Foam is able to build up a stable layer, which does not settle in the secondary clarifier. Foam in digestion causes a reduction of the degree of stabilisation and of the biogas production. We use low-frequency ultrasound to combat filamentous organisms in bulking sludge. Low-frequency ultrasound is suitable to create high local shear stresses, which are capable of breaking the filamentous structures of the sludge. After preliminary lab-scale tests now a full-scale new ultrasound equipment is operating at Reinfeld sewage treatment plant, Germany. The objective of this study is to explore the best ultrasound configuration to destroy the filamentous structure of bulking and foaming sludge in a substainable way. Later this study will also look into the effects of ultrasound treated bulking sludge on the anaerobic digestion process. Up to now results show that the settling behaviour of bulking sludge is improved. The minimal ultrasound energy input for destruction of bulking structure was determined. (orig.)

  19. Strategy for minimization of excess sludge production from the activated sludge process. (United States)

    Liu, Y; Tay, J H


    Increased attention has been given to minimization of sludge production from activated sludge process since environmental regulations are being more and more stringent in relation to excess sludge disposal. In a biological process, the more organic carbon utilized in carbon dioxide production, the fewer sludge produced, and vice versa. This paper, therefore, reviews strategies developed for minimization of excess sludge production, such as oxic-settling-anaerobic process, high dissolved oxygen process, uncoupler-containing activated sludge process, ozonation-combined activated sludge process, control of sludge retention time and biodegradation of sludge in membrane-assisted reactor. In these modified activated sludge processes, excess sludge production can be reduced by 20-100% without significant effect on process efficiency and stability. It is expected that this paper would be helpful for researchers and engineers to develop novel and efficient operation strategy to minimize sludge production from biological systems.

  20. Wasting Away: To Sludge or Not to Sludge?

    Directory of Open Access Journals (Sweden)

    L Nicolle


    Full Text Available Following a century of high standards of sanitation, food and water safety in North America are often taken for granted. Recent outbreaks of illness attributed to food and water contamination, however, have challenged this complacency. Now, sludge is added to the list of concerns. Sewage sludge is the muddy substance that remains after the treatment of municipal sewage. This material includes not only human waste, but also household and industrial toxic wastes disposed of in local sewers. Federal and provincial Canadian regulations support the use of this material as fertilizer, within acceptable guidelines, as does the Environmental Protection Agency in the United States. The safety of sludge, however, is questioned by some individuals and groups. Specifically, the risk of infectious agents and toxins to workers or other exposed individuals, and the potential for heavy metals and organic chemicals to be transferred from sludge-treated fields into crops are concerns.

  1. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge

    DEFF Research Database (Denmark)

    Hansen, H.K.; Christensen, Iben Vernegren; Ottosen, Lisbeth M.


    . Casagrande's coefficients were determined for the four materials at different water contents. The experiments in this work showed that chalk could be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM by electroosmosis......Electroosmotic dewatering has been tested in laboratory cells on four different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material....... The process was not optimised indicating that higher dry matter contents could be achieved by electroosmosis. It was possible to relate Casagrande's coefficient directly to the electroosmotic coefficient obtained by dewatering experiments....

  2. Technology Assessment Report: Aqueous Sludge Gasification Technologies (United States)

    The study reveals that sludge gasification is a potentially suitable alternative to conventional sludge handling and disposal methods. However, very few commercial operations are in existence. The limited pilot, demonstration or commercial application of gasification technology t...

  3. Filterability and Sludge Concentration in Membrane Bioreactors


    Lousada-Ferreira, M.


    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of the sludge to be filtrated through a membrane, in a wastewater treatment system designated as Membrane Bioreactor (MBR). An MBR is a wastewater treatment system that combines an activated sludge proc...

  4. Excess sludge reduction in activated sludge processes by integrating ultrasound treatment

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Elvira, S.; Fdz-Polanco, M.; Plaza, F. I.; Garralon, G.; Fdz-Polanco, F.


    Biological sludge produced in the activated sludge process can be minimised modifying the water line, the sludge line or the final disposal strategy. Selecting the water line the general idea is to reduce the sludge producing the yield coefficient by means of the called lysis cryptic growth process. The main techniques referenced in literature are onization, chlorination and chemical and heat treatment. Ultrasounds are widely used to increase anaerobic biodegradability but are not reported as system to control excess sludge production. (Author)

  5. Heavy metals precipitation in sewage sludge

    NARCIS (Netherlands)

    Marchioretto, M.M.; Rulkens, W.H.; Bruning, H.


    There is a great need for heavy metal removal from strongly metal-polluted sewage sludges. One of the advantages of heavy metal removal from this type of sludge is the possibility of the sludge disposal to landfill with reduced risk of metals being leached to the surface and groundwater. Another

  6. Technology Assessment Report - Aqueous Sludge Gasification Technologies (United States)

    Sludge production in the United States is increasing with an increase in population. An estimated 7.2 million dry tons of treated and tested sewage sludge was generated in 2004 and 4.1 million tons of paper mill sludge was produced in 1995. Consequently, there is an increased ne...

  7. Paper Sludge Reuse in Lightweight Aggregates Manufacturing. (United States)

    Chen, How-Ji; Hsueh, Ying-Chih; Peng, Ching-Fang; Tang, Chao-Wei


    The lightweight aggregates used by the civil engineering market are sintered at a high temperature, about 1200 °C. In times of high energy prices and regulation of carbon dioxide emissions, lightweight aggregate products of the high-temperature process in sales marketing are not readily accepted. This study developed a sintered-type paper sludge lightweight aggregate. In order to reduce energy consumption, substitution of some reservoir sediment clay in paper sludge substitutes is to be expected. The study used two types of paper sludge (green clay paper sludge and paper pulp sludge). The sintering temperature was reduced effectively as the green clay paper sludge was substituted for some of the reservoir sediment clay, and the optimum substitute ranges of green clay paper sludge were 10%-50%. The optimum substitute ranges of the paper pulp sludge were 10%-40%. Test results show that the properties of aggregates have a particle density of 0.66-1.69 g/cm³, a water absorption of 5%-30%, and a loss on ignition of 10%-43%. The loss on ignition of aggregate became greater with the increase in paper sludge content. This means that the calorific value provided by the paper sludge will increase as paper sludge content increases. Paper sludge can therefore be considered a good material to provide heat energy for sintering lightweight aggregate.

  8. 40 CFR 61.54 - Sludge sampling. (United States)


    ..., preparation, and analysis of sludge samples shall be accomplished according to Method 105 in appendix B of... may use Method 105 of appendix B and the procedures specified in this section. (1) A sludge test shall... be sampled according to paragraph (c)(1) of this section, sludge charging rate for the plant shall be...

  9. Conditioning of sewage sludge via combined ultrasonication-flocculation-skeleton building to improve sludge dewaterability. (United States)

    Zhu, Cheng; Zhang, Panyue; Wang, Hongjie; Ye, Jie


    Strong water trapping ability of polyelectrolyte flocculated sludge and high compressibility of sludge filter cake greatly hindered the further improvement of sludge dewaterability. Ultrasound (US) was used to strip the water from the sludge flocs through sludge disintegration, traditional cationic polyacrylamide (CPAM) was applied to reconstruct the sludge aggregates through flocculation, and rice husk (RH) was utilized to improve the permeability of sludge filter cake as skeleton builders in this paper. The feasibility of combined US-CPAM-RH sludge conditioning was demonstrated, and single and co-conditioning processes were compared to explore the synergetic effect and mechanisms of US-CPAM-RH sludge conditioning. The results indicated that the sludge dewaterability was considerably improved by the combined US-CPAM-RH conditioning compared with that of raw sludge. The optimal ultrasonication condition was 0.3W/ml for 12s with an Ultrasound frequency of 22kHz, and the RH and CPAM dosage was 50.0wt% and 20mg/L, respectively, which resulted in a shortest time to filter (TTF) of 43s and a lowest moisture content of sludge filter cake of 62.22%. The US mainly stripped the extracellular polymeric substances and water from the sludge flocs, leading to an obvious increase of concentration of proteins and polysaccharides in sludge filtrate. The CPAM and RH addition resulted in a remarkable sludge floc growth to a mean diameter d(0.5) of 128.85µm after combined US-CPAM-RH conditioning. Moreover, scanning electron microscopy (SEM) results clearly showed that the combined US-CPAM-RH conditioning formed a more porous structure of sludge filter cake with a porosity increase of 98.80% and a compressibility decrease of 37.81% compared with that of raw sludge. Thus, the US-CPAM-RH co-conditioning could significantly improve the sludge dewaterability. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Fermentation and chemical treatment of pulp and paper mill sludge (United States)

    Lee, Yoon Y; Wang, Wei; Kang, Li


    A method of chemically treating partially de-ashed pulp and/or paper mill sludge to obtain products of value comprising taking a sample of primary sludge from a Kraft paper mill process, partially de-ashing the primary sludge by physical means, and further treating the primary sludge to obtain the products of value, including further treating the resulting sludge and using the resulting sludge as a substrate to produce cellulase in an efficient manner using the resulting sludge as the only carbon source and mixtures of inorganic salts as the primary nitrogen source, and including further treating the resulting sludge and using the resulting sludge to produce ethanol.

  11. Thermal analysis of kieselguhr sludge

    Directory of Open Access Journals (Sweden)

    S. T. Antipov


    Full Text Available It’s currently necessary to clarify the mechanisms of thermodynamic and mass transfer processes in capillary porous media. In this paper we obtain the thermogravimetric curves of evaporation drying kieselguhr sludge. It is also an analysis of the curves, allowing to choose the optimum conditions of drying.


    African Journals Online (AJOL)

    A critical examination of the two plots reveals that a relationship might exist between the two concepts. Also, the analysis of the filtration results obtained using both the old and the new concepts, confirms that both Sludge Dewaterability Number values and the Specific resistance values decrease with an increase in the ...

  13. Effects of Sludge-amendment on Mineralization of Pyrene and Microorganisms in Sludge and Soil

    DEFF Research Database (Denmark)

    Klinge, C; Gejlsbjerg, B; Ekelund, Flemming


    . Sludge-amendment enhanced the mineralization of pyrene in the soil compared to soil without sludge, and the most extensive mineralization was observed when the sludge was kept in a lump. The number of protozoa, heterotrophic bacteria and pyrene-mineralizing bacteria was much higher in the sludge compared...... to the soil. The amendment of sludge did not affect the number of protozoa and bacteria in the surrounding soil, which indicated that organic contaminants in the sludge had a little effect on the number of protozoa and bacteria in the surrounding soil...

  14. Methods for Converter Sludge Dehydration Intensification (United States)

    Vakhromeev, M. I.; Moreva, Y. A.; Starkova, L. G.


    The article considers the intensification methods for converter sludge dehydration exemplified by the sludges of the Oxygen Converter Workshop (OCW) of the Open Joint-Stock Company “Magnitogorsk Iron and Steel Works” (MMK, OJSC), one of the largest metallurgical companies in the Southern Urals. Converter sludges can contain up to 45-70% of ferrum [21] which is interesting in terms of their use as an addition to a sinter-feed mixture. Sludge intensifies the sintering process. It positively influences pelletizing and fusion mixture melting dynamics at sintering. Over the period of the converter sludge dehydration complex operation at the OCW, MMK, OJSC, it was revealed that processing results in obtaining of high humidity sludge. It causes sludge freezing during the winter period, thus, its transportation involves extra costs for sludge warming up. To resolve the above-mentioned problem, the following works were performed in 2016: - experimental studies of how the application of the low-molecular anionic flocculate “SEURVEY” FL-3 influences sludge humidity reduction. - experimental studies of how the filtering press process operation parameters influence sludge humidity reduction. The new flocculate application didn't lower the dehydrated sludge humidity (the objective was the humidity of not more than 15%). Basing upon the conducted research results, we can make a conclusion that putting into operation the sewage water reactant treatment technology with the use of “SEURVEY”, FL-3 (H-10) is not recommended. The research of the influence the filtering press process parameters have on the dehydration process intensification demonstrated that reaching of the obtained residue humidity value lower than 15% is possible under the reduction of the filtering press chamber depths to 30 mm and with the application of additional operation “Residue drying” with compressed air. This way of the sludge dehydration problem resolving at filtering presses of the

  15. Mechanical and hydraulic properties of sludge deposit on sludge drying reed beds (SDRBs): influence of sludge characteristics and loading rates. (United States)

    Vincent, Julie; Forquet, Nicolas; Molle, Pascal; Wisniewski, Christelle


    This work was designed to study the hydraulic properties of sludge deposit, focusing on the impact of operating conditions (i.e. loads and feeding frequencies) on air entrance (aerobic mineralization optimization) into the sludge deposit. The studied sludge deposits came from six 2m(2) pilot-scale SDRBs that had been in operation for 50 months with three different loads of 30, 50, and 70 kg of SSm(-2) y(-1). Two influents were assessed (i.e. activated sludge and septage) presenting different characteristics (i.e. pollutant contents, physical properties...). Two experimental approaches were employed based on establishing the water retention curve (capillary pressure versus volumetric water content) and the hydrotextural diagram to determine the hydraulic properties of sludge deposit. The study obtained valuable information for optimizing operating conditions, specifically for efficient management of loading frequency to optimize aerobic conditions within the sludge deposit. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. K Basin sludge dissolution engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.


    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  17. Potential priority pollutants in sewage sludge

    DEFF Research Database (Denmark)

    Eriksson, Eva; Christensen, Nina; Schmidt, Jens Ejbye


    compounds (XOCs) present in the sludge. Application on land used for agriculture is, therefore, not socially acceptable in some countries, e.g., Sweden. In this study, literature reviews showed that 541 XOCs potentially could be present in sewage sludge due to their presence in e.g. construction materials......, pharmaceuticals, personal care products etc. 192 compounds have been quantified in sewage sludge, which indicate that, although many XOCs have been measured in sludge, there are potentially a vast number of compounds present that have not been analyzed for yet. In a hazard identification of the quantified...... assessing sludge quality. They were compared with European legislations and discussed in regard for pointing out the need for mitigation such as substitution. Furthermore, the potential need for implementation of sludge treatment trains in order to meet the society's needs was addressed....

  18. [Isolation of filamentous fungi capable of enhancing sludge dewaterability and study of mechanisms responsible for the sludge dewaterability enhancement]. (United States)

    Zhou, Yu-Jun; Fu, Hao-Yi; Fan, Xian-Feng; Wang, Zhen-Yu; Zheng, Guan-Yu


    To study the influence of filamentous fungi on the sludge dewaterability is very significant for the development of biological treatment methods for enhancing sludge dewaterability. In this study, filamentous fungi capable of enhancing sludge dewaterability were isolated from sewage sludge and the related mechanisms responsible for the sludge dewaterability enhancement were investigated. A filamentous fungus Mucor circinelloides ZG-3 was successfully isolated from sludge, and sludge dewaterability could be drastically improved by this fungus. Further study revealed that the enhancement of sludge dewaterability was influenced by inoculation method, inoculum size and solid content of sludge. The optimal inoculation method was mycelia inoculation, the optimal inoculum size was 10%, and the optimal solid content of sludge was about 4%. Under the optimized conditions, the specific resistance to filtration (SRF) of sludge could be decreased by 75.1% after being treated by M. circinelloides ZG-3. After the treatment, the COD value of sludge supernatant was only 310 mg x L(-1), and the treated sludge still exhibited good settleability. During the treatment of sewage sludge by M. circinelloides ZG-3, the mechanisms responsible for the sludge dewaterability enhancement included the degradation of sludge extracellular polymeric substances (EPS) and the decrease of sludge pH. Therefore, the treatment of sewage sludge using M. circinelloides ZG-3 is a useful and novel method for sludge conditioning.

  19. Development of sludge filterability test to assess the solids removal potential of a sludge bed

    NARCIS (Netherlands)

    Mahmoud, N.A.; Zandvoort, M.H.; Lier, van J.B.; Zeeman, G.


    A qualitative sludge characterisation technique called ¿sludge filterability technique¿ has been developed. This technique enables the determination of the sludge potential for the physical removal of solids, weighing the effect of different process parameters on solids removal and identifying the

  20. Impact of sludge properties on solid-liquid separation of activated sludge

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard


    Solid-liquid separation of activated sludge is important both directly after the biological treatment of wastewater and for sludge dewatering. The separation of solid from the treated wastewater can be done by clarifiers (conventional plants) or membrane (MBR). Further, part of the sludge is taken...

  1. An Economic comparison of sludge irradiation and alternative methods of municipal sludge treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstrom, S.B.; McGuire, H.E.


    The relative economics of radiation treatment and other sludge treatment processes are reported. The desirability of radiation treatment is assessed in terms of cost and the quality of the treated sludge product. The major conclusions of this study are: radiation treatment is a high-level disinfection process. Therefore, it should only be considered if high levels of disinfection are required for widespread reuse of the sludge; the handling, transporting and pathogen growback problems associated with disinfected wet sludge makes it less attractive for reuse than dry sludge; radiation of composted sludge produces a product of similar quality at less cost than any thermal treatment and/or flash drying treatment option for situations where a high degree of disinfection is required; and heavy metal concerns, especially cadmium, may limit the reuse of sludge despite high disinfection levels. It is recommended that radiation treatment of sludge, particularly dry sludge, continue to be studied. A sensitivity analysis investigating the optimal conditions under which sludge irradiation operates should be instigated. Furthermore, costs of adding sludge irradiation to existing sludge treatment schemes should be determined.

  2. Interaction between digestion conditions and sludge physical characteristics and behaviour for anaerobically digested primary sludge

    NARCIS (Netherlands)

    Mahmoud, N.; Zeeman, G.; Gijzen, H.; Lettinga, G.


    The interaction between digestion conditions and the sludge physical characteristics and behaviour was investigated for anaerobically digested primary sludge in completely stirred tank reactors (CSTRs). The CSTRs were operated to maintain sludge retention times (SRTs) of 10, 15, 20 and 30 days and

  3. Utilizing waste activated sludge for animal feeding

    Energy Technology Data Exchange (ETDEWEB)

    Beszedits, S.


    Activated sludge has a high protein content and is a good source of B-group vitamins and generally also of minerals (Ca, Mg, Fe and K). Propionibacterium freudenreichii can be readily incorporated into the activated sludge to synthesize vitamin B12, particularly high vitamin yields being obtained with sewage mixed with dairy waste. Numerous examples of successful use of activated sludge in animal feeding are given.

  4. Sewage sludge as a biomass energy source

    Directory of Open Access Journals (Sweden)

    Pavel Kolat


    Full Text Available The major part of the dry matter content of sewage sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary microbiological sludge. The sludge also contains a substantive amount of inorganic material and a small amount of toxic components. There are many sludge-management options in which production of energy is one of the key treatment steps. The most important options are anaerobic digestion, co-digestion, incineration in combination with energy recovery and co-incineration in coal-fired power plants. The goal of our applied research is to verify, if the sludge from waste water treatment plants may be used as a biomass energy source in respect of the EU legislation, which would comply with emission limits or the proposal of energy process optimizing the preparation of coal/sludge mixture for combustion in the existing fluid bed boilers in the Czech Republic. The paper discusses the questions of thermal usage of mechanically drained stabilized sewage sludge from the waste water treatment plants in the boiler with circulated fluid layer. The paper describes methods of thermal analysis of coal, sewage sludge and its mixtures, mud transport to the circulating fluidised bed boiler, effects on efficiency, operational reliability of the combustion equipment, emissions and solid combustion residues.

  5. Determination of sorption of seventy five pharmaceuticals in sewage sludge

    DEFF Research Database (Denmark)

    Hörsing, Maritha; Ledin, Anna; Grabic, Roman


    Sorption of 75 active pharmaceutical ingredients (APIs) to three different types of sludge (primary sludge, secondary sludge with short and long sludge age respectively) were investigated. To obtain the sorption isotherms batch studies with the APIs mixture were performed in four nominal concentr......Sorption of 75 active pharmaceutical ingredients (APIs) to three different types of sludge (primary sludge, secondary sludge with short and long sludge age respectively) were investigated. To obtain the sorption isotherms batch studies with the APIs mixture were performed in four nominal...... was estimated to >80%. 24 APIs were estimated to be present in the liquid phase between 20 and 80%, and 14 APIs were found to have...

  6. Speciation of mercury in sludge solids: washed sludge

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Lourie, A. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The objective of this applied research task was to study the type and concentration of mercury compounds found within the contaminated Savannah River Site Liquid Waste System (SRS LWS). A method of selective sequential extraction (SSE), developed by Eurofins Frontier Global Sciences1,2 and adapted by SRNL, utilizes an extraction procedure divided into seven separate tests for different species of mercury. In the SRNL’s modified procedure four of these tests were applied to a washed sample of high level radioactive waste sludge.

  7. Filterability and Sludge Concentration in Membrane Bioreactors

    NARCIS (Netherlands)

    Lousada-Ferreira, M.


    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of

  8. Sustainability of Domestic Sewage Sludge Disposal

    Directory of Open Access Journals (Sweden)

    Claudia Bruna Rizzardini


    Full Text Available Activated sludge is now one of the most widely used biological processes for the treatment of wastewaters from medium to large populations. It produces high amounts of sewage sludge that can be managed and perceived in two main ways: as a waste it is discharged in landfill, as a fertilizer it is disposed in agriculture with direct application to soil or subjected to anaerobic digestion and composting. Other solutions, such as incineration or production of concrete, bricks and asphalt play a secondary role in terms of their degree of diffusion. The agronomical value of domestic sewage sludge is a proved question, which may be hidden by the presence of several pollutants such as heavy metals, organic compounds and pathogens. In this way, the sustainability of sewage sludge agricultural disposal requires a value judgment based on knowledge and evaluation of the level of pollution of both sewage sludge and soil. The article analyzed a typical Italian case study, a water management system of small communities, applying the criteria of evaluation of the last official document of European Union about sewage sludge land application, the “Working Document on Sludge (3rd draft, 2000”. The report brought out good sewage sludge from small wastewater treatment plants and soils quality suggesting a sustainable application.

  9. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.


    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent

  10. Impact of sludge deposition on biodiversity. (United States)

    Manzetti, Sergio; van der Spoel, David


    Sludge deposition in the environment is carried out in several countries. It encompasses the dispersion of treated or untreated sludge in forests, marsh lands, open waters as well as estuarine systems resulting in the gradual accumulation of toxins and persistent organic compounds in the environment. Studies on the life cycle of compounds from sludge deposition and the consequences of deposition are few. Most reports focus rather on treatment-methods and approaches, legislative aspects as well as analytical evaluations of the chemical profiles of sludge. This paper reviews recent as well as some older studies on sludge deposition in forests and other ecosystems. From the literature covered it can be concluded that sludge deposition induces two detrimental effects on the environment: (1) raising of the levels of persistent toxins in soil, vegetation and wild life and (2) slow and long-termed biodiversity-reduction through the fertilizing nutrient pollution operating on the vegetation. Since recent studies show that eutrophication of the environment is a major threat to global biodiversity supplying additional nutrients through sludge-based fertilization seems imprudent. Toxins that accumulate in the vegetation are transferred to feeding herbivores and their predators, resulting in a reduced long-term survival chance of exposed species. We briefly review current legislation for sludge deposition and suggest alternative routes to handling this difficult class of waste.

  11. Microwave enhanced stabilization of heavy metal sludge. (United States)

    Hsieh, Ching-Hong; Lo, Shang-Lien; Chiueh, Pei-Te; Kuan, Wen-Hui; Chen, Ching-Lung


    A microwave process can be utilized to stabilize the copper ions in heavy metal sludge. The effects of microwave processing on stabilization of heavy metal sludge were studied as a function of additive, power, process time, reaction atmosphere, cooling gas, organic substance, and temperature. Copper leach resistance increased with addition of aluminum metal powder, with increased microwave power, increased processing time, and using a gaseous environment of nitrogen for processing and air for cooling [N2/air]. The organic in the sludge affected stabilization, whether or not the organic smoldered. During heating in conventional ovens, exothermic oxidation of the organic resulted in sludge temperatures of about 500 degrees C for oven control temperatures of 200-500 degrees C. After microwave heating dried the sludge, the sludge temperature rose to 500 degrees C. The reaction between copper ions and metal aluminum in the dried sludge should be regarded as a solid phase reaction. Adding aluminum metal powder and reaction temperature were the key parameters in stabilizing copper in the heavy metal sludge, whether heated by microwave radiation or conventional oven. The mass balance indicates insignificant volatization of the copper during heating.

  12. Recycling of phosphorus in sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Tore; Sogn, Trine A.; Asdal, Aasmund; Saeboe, Arne


    In order to examine the fertilizing effect of P in different sewage sludge a pot experiment with rye grass growing in a moraine and a clay soil with application of different kinds of sewage sludge was carried out. Data on pH, water extractable P and ammonium acetate lactate extractable P in soil, and yield P content showed that Sewage sludge application significantly influenced the soil pH and may thereby indirectly influence the plants' general access to essential nutrients in the soil. Beside of the purification history of the sewage sludge, both the soil content of available P and the P adsorption capability of the soil must be considered when advising sludge application to crop production. Biological purification without chemical additives and Ca treatment of the sludge gave the highest amount of plant available P and also the best utilization of the P applied as sludge. Although low concentrations of water extractable P after addition of sewage sludge the considerable accumulation of total P in the surface soil (50-95% increase) must be considered a potential environmental risk due to possible surface P runoff by erosion. (author)

  13. Electrodialytic removal of cadmium from wastewater sludge

    DEFF Research Database (Denmark)

    Jakobsen, M. R.; Fritt-Rasmussen, Janne; Nielsen, S.


    /solid (ml/g fresh sludge) ratio was between 1.4 and 2. Three experiments were performed where the sludge was suspended in distilled water, citric acid or HNO"3. The experimental conditions were otherwise identical. The Cd removal in the three experiments was 69, 70 and 67%, respectively, thus the removal...

  14. Modelling Analysis of Sewage Sludge Amended Soil

    DEFF Research Database (Denmark)

    Sørensen, P. B.; Carlsen, L.; Vikelsøe, J.

    The topic is risk assessment of sludge supply to agricultural soil in relation to xenobiotics. A large variety of xenobiotics arrive to the wastewater treatment plant in the wastewater. Many of these components are hydrophobic and thus will accumulate in the sludge solids and are removed from...

  15. Gall-bladder sludge: lessons from ceftriaxone. (United States)

    Kim, Y S; Kestell, M F; Lee, S P


    Ceftriaxone-associated sludge has been a fascinating story. The occurrence is novel and unique. It has produced a model of gall-bladder sludge in humans. This phenomenon has taught us a great deal about biliary lipid and organic anion excretion by the liver, and the physical chemistry of calcium and calcium sensitive anions. It has added further insights into the pathophysiology of gall-bladder sludge formation. It points to a combination of a hepatic effect where the liver secretes a biochemically abnormal bile, and a gall-bladder effect which provides an environment for precipitation, in order for sludge to develop. The precipitated calcium ceftriaxone has prompted us to re-evaluate the imaging criteria for the diagnosis of gall-bladder sludge versus gallstones. Above all, the rapid onset and rapid disappearance of ceftriaxone sludge has mirrored in a compressed, encapsulated form, the natural history of gall-bladder sludge. It has reminded us that, like gallstones, biliary sludge is usually benign and asymptomatic. However just because it is smaller than gallstones does not mean it cannot cause problems. It can disappear or it can become a calcium ceftriaxone gallstone.

  16. Burning sewage sludge in cement kilns

    Energy Technology Data Exchange (ETDEWEB)

    Obrist, A.


    Full-scale industrial trial burning of sewage sludge in cement kilns in Switzerland is reported. Tests with dried sludge, kiln operation, chimney emissions, clinker and cement are discussed, and possibilities open to Swiss cement industry, and significance within the overall scope of waste disposal are outlined.

  17. Beneficial use of sludge in building components

    Energy Technology Data Exchange (ETDEWEB)

    Alleman, J.E.


    Results are presented of a study in which sludge was introduced in the manufacture of brick. More than 300 bench-scale, sludge-amended bricks were produced with initial volumetric sludge additions of from 16% to 50%. These specimens looked, felt, and smelled like standard bricks, and those with sludge additions of 30% or less were found capable of meeting the appropriate technical standards. Three full-scale runs have been completed by a commercial manufacturer, and almost one million bricks have been produced. These bricks were found comparable to normal, unadulterated bricks; in fact, the incorporation of sludge was believed to be beneficial due to related improvements in the brick's water absorption properties. The name 'biobrick' is used to refer to the new product.

  18. Dewaterability of sludge digested in extended aeration plants using ...

    African Journals Online (AJOL)

    Dewaterability of unconditioned sludge digested in full scale and lab scale experiments using either extended aeration (EA) or anaerobic digestion were compared on full and lab scale sand drying beds. Sludge digested in EA plants resulted in improvement in sludge dewaterability compared to sludge digested ...

  19. Characterization and treatment of sludge from the petroleum industry

    African Journals Online (AJOL)

    ... sludge can undergo biodegradation and suggests that biological method could be used in effecting treatment to the sludge. The high conductivity also indicated that the sludge can be treated by physicochemical method of coagulation and flocculation. Keywords: Petroleum sludge, pollution characteristics, eutrophication, ...

  20. Priority and emerging pollutants in sewage sludge and fate during sludge treatment. (United States)

    Mailler, R; Gasperi, J; Chebbo, G; Rocher, V


    This paper aims at characterizing the quality of different treated sludges from Paris conurbation in terms of micropollutants and assessing their fate during different sludge treatment processes (STP). To achieve this, a large panel of priority and emerging pollutants (n=117) have been monitored in different STPs from Parisian wastewater treatment plants including anaerobic digestion, thermal drying, centrifugation and a sludge cake production unit. Considering the quality of treated sludges, comparable micropollutant patterns are found for the different sludges investigated (in mg/kg DM - dry matter). 35 compounds were detected in treated sludges. Some compounds (metals, organotins, alkylphenols, DEHP) are found in every kinds of sludge while pesticides or VOCs are never detected. Sludge cake is the most contaminated sludge, resulting from concentration phenomenon during different treatments. As regards treatments, both centrifugation and thermal drying have broadly no important impact on sludge contamination for metals and organic compounds, even if a slight removal seems to be possible with thermal drying for several compounds by abiotic transfers. Three different behaviors can be highlighted in anaerobic digestion: (i) no removal (metals), (ii) removal following dry matter (DM) elimination (organotins and NP) and iii) removal higher than DM (alkylphenols - except NP - BDE 209 and DEHP). Thus, this process allows a clear removal of biodegradable micropollutants which could be potentially significantly improved by increasing DM removal through operational parameters modifications (retention time, temperature, pre-treatment, etc.). Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Investigation of Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Aušra Mažeikienė


    Full Text Available It is important to control not only the large wastewater treatment plants work, but also the work of individual small wastewater treatment plants for the protection of environment. Individual small wastewater treatment plants can become the local sources of pollution, when they are not functioning properly. Sewage purification indicators are not always the same as declared at wastewater treatment plants documentation in real conditions, so it is important to control the properly work of individual small wastewater treatment plants. The work of the small wastewater treatment plant AT-6 was analyzed by the treated sewage results (BDS7, SM, NH4-N, NO3-N, NO2-N, PO4-P, the quality of activated sludge, biological indicators and enzymatic activity in this article. The nitrification process was not going very well by the results of research, because there was the 72 mg/l concentration of ammonium nitrogen remaining in the cleaned wastewater. The morphological study of the activated sludge has confirmed the hypothesis that the necessary conditions for nitrification process were not established. The oxygen supply was increased and the small wastewater treatment plant functioning become more efficient, because nitrification process started working properly – there was less than 1 mg/l of ammonium nitrogen remaining in the cleaned wastewater.

  2. Sustainable sludge management in developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, B.; Barrios, J.A.; Mendez, J.M.; Diaz, J.


    Worldwide, unsanitary conditions are responsible of more than three million deaths annually. One of the reasons is the low level of sanitation in developing countries. Particularly, sludge from these regions has a high parasite concentration and low heavy metal content even though the available information is limited. Different issues needed to achieve a sustainable sludge management in developing nations are analysed. Based on this analysis some conclusions arise: sludge management plays an important role in sanitation programs by helping reduce health problems and associated risks; investments in sanitation should consider sludge management within the overall projects; the main restriction for reusing sludge is the high microbial concentration, which requires a science-based decision of the treatment process, while heavy metals are generally low; the adequate sludge management needs the commitment of those sectors involved in the development and enforcement of the regulations as well as those that are directly related to its generation, treatment, reuse or disposal; current regulations have followed different approaches, based mainly on local conditions, but they favour sludge reuse to fight problems like soil degradation, reduced crop production, and the increased use of inorganic fertilizers. This paper summarises an overview of theses issues. (author)

  3. Bio THELYS: A new sludge reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Chauzy, Julien; Cretenot, Didier; Patria, Lucie; Fernandes, Paulo; Sauvegrain, Patrick; Levasseur, Jean-Pierre


    New technologies for reducing the sludge production of municipal or industrial WWTP have been appeared during the last few years. One of these innovative processes, Bio THELYS, consists in enhancing the biodegradability of sludge by a stage of thermal hydrolysis. The hydrolysed sludge could then be sent upstream to a biological step either aerobic or anaerobic. The objective is to increase the global mineralisation of the pollution entering the WWTP in order to decrease the waste leaving it, i.e. mainly the sludge. A 2500 population equivalent prototype was installed on a WWTP, in Champagne - France. Thermal hydrolysis is carried out under a temperature of 150-185{sup o}C, a pressure of 10-15 bar with an hydraulic retention time of 30-60 minutes. Thermal hydrolysis is implemented on a secondary recycling loop on the biological basin. Trials started in 1999 and are still on operation. A close monitoring of the WWTP was set up focusing especially on sludge characteristics, treated water quality, yield of sludge production reduction and plant operation. Bio THELYS could achieve a reduction in sludge production up to 70% on the plant. (author)

  4. [Pollution characteristics of heavy metals in sludge from wastewater treatment plants and sludge disposal in Chinese coastal areas]. (United States)

    Zhang, Can; Chen, Hong; Yu, Yi-Xuan; Wang, Li-Jun; Han, Jian-Bo; Tao, Ping


    Thirteen sludge samples from Guangzhou, Shanghai and Dalian were collected and analysed for heavy metals to investigate the distribution and variation trend of heavy metals in sludge from wastewater treatment plants in Chinese coastal areas. The results showed that contents of heavy metals in sludge varied significantly, and the average contents exhibited an order of Cr > Zn > Cu > Pb > As > Hg > Cd. Additionally, contents of Cr, Cu and As exceeded their corresponding standard levels. Compared with contents of heavy metals in 2006 and 2001, content of Zn in sludge increased while contents of Cr, Cu and As decreased. Results also indicated that the industrial sludge was more seriously polluted than domestic sludge in terms of Zn, Cu and As. Only 23% sludge samples exceeded the standards for fertilization of sludge, suggesting that most of the sludge could be disposed by land application. These results also provide further information about the establishment of ocean disposal assessment for sludge.

  5. Optimizing mixing mode and intensity to prevent sludge flotation in sulfidogenic anaerobic sludge bed reactors. (United States)

    Wang, Bo; Wu, Di; Ekama, George A; Huang, Hao; Lu, Hui; Chen, Guang-Hao


    Sludge flotation is a notorious problem in anaerobic wastewater treatment that can occur under various operational conditions and even cause the anaerobic process to completely fail. Despite having been documented for over three decades, its causes and remedies remain elusive, particularly for low-gas-production anaerobic processes such as sulfidogenic and anammox processes. This paper systematically studies sludge flotation in an anaerobic sulfidogenic process for saline domestic sewage treatment. Three lab-scale sulfidogenic reactors were operated in parallel with different modes of mixing (hydraulic, mechanical and pneumatic) at various mixing intensity levels at shear rates ranging from 0.7 to 6.6 s-1 to investigate reactor performance and sludge properties and their relationships with sludge flotation potential. The results indicate that a sulfidogenic reactor with low flotation potential have sludge with low hydrophobicity, low viscosity, and low (more negative) surface charge, while the sludge particle surfaces have high compactness and low roughness. These sludge properties enabled a sludge flotation potential of less than 20% to be maintained. Furthermore, our results show that i) mixing and extracellular polymeric substances (EPS), ii) EPS and sludge properties, and iii) sludge properties and sludge flotation potential are all strongly correlated (all the Spearman's rank correlation coefficients (Rs) are either over 0.64 (if positively correlated) or under -0.64 (if negatively correlated), at the 95% confidence level). Accordingly, sludge flotation can be resolved by controlling reactor mixing. Our findings provide a method to optimize the design and operation of anaerobic sulfidogenic reactors that can be extended to similar low-gas-production anaerobic bioreactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Improvement of anaerobic digestion of sludge

    Energy Technology Data Exchange (ETDEWEB)

    Dohanyos, Michael; Zabranska, Jana; Kutil, Josef; Jenicek, Pavel


    Anaerobic digestion improvement can be accomplished by different methods. Besides optimization of process conditions is frequently used pretreatment of input sludge and increase of process temperature. Thermophilic process brings a higher solids reduction and biogas production, the high resistance to foaming, no problems with odour, the higher effect of destroying pathogens and the improvement of the energy balance of the whole treatment plant. Disintegration of excess activated sludge in lysate centrifuge was proved in full-scale conditions causing increase of biogas production. The rapid thermal conditioning of digested sludge is acceptable method of particulate matter disintegration and solubilization. (author)

  7. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye


    by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change......-rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

  8. Environmental sustainability of wastewater sludge treatments

    DEFF Research Database (Denmark)

    Boyer-Souchet, Florence; Larsen, Henrik Fred

    resources. As part of a sustainability assessment (or “best practice evaluation”), a comparison between the existing and new sludge handling techniques have been done by use of life cycle assessment (LCA).The concept of induced impacts as compared to avoided impacts when introducing a new sludge treatment...... technology is used for the environmental comparison. Emissions from the treatment of the sludge as well as energy consumption and production, chemical consumption, infrastructures and transport are taken into account. This poster will present the results of LCA’s performed on different inertisation...

  9. Ultrasonic reduction of excess sludge from activated sludge system: energy efficiency improvement via operation optimization. (United States)

    He, Junguo; Wan, Tian; Zhang, Guangming; Yang, Jing


    This paper studied the influences of operational parameters to improve the energy efficiency during 'ultrasonic lysis-cryptic growth' sludge reduction. Subsequent batch reactor with a hydraulic retention time of 8 h was used to treat urban sewage, and ultrasound wave with a specific energy of 20 kWh/kg TS was employed for sludge lysis. A new index, EE, was defined to evaluate the energy efficiency in ultrasonic lysis-cryptic growth sludge reduction system. Results showed that the most important operational parameter was the proportion of sonicated sludge (SP), which determined the energy consumption and significantly impacted the energy efficiency. The upper limit of SP in this study was 30%, beyond which the effluent quality was unacceptable. Higher SP caused heavier sludge reduction but more energy consumption; when SP was 30%, the excess sludge reduction was the greatest (67.6%) and the energy consumption was the highest (0.101 kWh/d). With a given SP, frequent sludge lysis was adverse to sludge reduction. In summary, the recommended conditions for 'ultrasonic lysis-cryptic growth' sludge reduction were SP of 15%, lysis frequency of 1 time/day. Under these conditions, the highest energy efficiency of 0.012 kg TS/kWh was achieved. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Evaluating sedimentation problems in activated sludge treatment plants operating at complete sludge retention time. (United States)

    Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Pekridis, George; Taousanidis, Nikolaos


    Zero net sludge growth can be achieved by complete retention of solids in activated sludge wastewater treatment, especially in high strength and biodegradable wastewaters. When increasing the solids retention time, MLSS and MLVSS concentrations reach a plateau phase and observed growth yields values tend to zero (Yobs ≈ 0). In this work, in order to evaluate sedimentation problems arised due to high MLSS concentrations and complete sludge retention operational conditions, two identical innovative slaughterhouse wastewater treatment plants were studied. Measurements of wastewaters' quality characteristics, treatment plant's operational conditions, sludge microscopic analysis and state point analysis were conducted. Results have shown that low COD/Nitrogen ratios increase sludge bulking and flotation phenomena due to accidental denitrification in clarifiers. High return activated sludge rate is essential in complete retention systems as it reduces sludge condensation and hydraulic retention time in the clarifiers. Under certain operational conditions sludge loading rates can greatly exceed literature limit values. The presented methodology is a useful tool for estimation of sedimentation problems encountered in activated sludge wastewater treatment plants with complete retention time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.


    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD{sub i}nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  12. Progress and perspectives of sludge ozonation as a powerful pretreatment method for minimization of excess sludge production. (United States)

    Chu, Libing; Yan, Sangtian; Xing, Xin-Hui; Sun, Xulin; Jurcik, Benjamin


    The treatment and disposal of excess sludge represents a bottleneck in wastewater treatment plants (WWTP) worldwide, due to environmental, economic, social and legal factors. The ideal solution to the problem of sludge disposal is to combine sludge reduction with the removal of pollution at the source. This paper presents an overview of the potential of ozonation in sludge reduction. The full-scale application of ozonation in excess sludge reduction is presented. Improvements in the biodegradability of the ozonated sludge were confirmed. The introduction of ozonation into activated sludge did not significantly influence effluent quality but improved the settling properties of the sludge. An operation with a suitable sludge wasting ratio seems to be necessary to prevent accumulation of inorganic and inert particles for long-term operation. Sludge ozonation to reduce excess sludge production may be economical in WWTP which have high sludge disposal costs and operational problems such as sludge foaming and bulking. The recommended ozone dose ranges from 0.03 to 0.05 g O(3)/g TSS, which is appropriate to achieve a balance between sludge reduction efficiency and cost. An effort to design and optimize an economic sludge reduction process is necessary.


    Energy Technology Data Exchange (ETDEWEB)



    The CH2M HILL Plateau Remediation Company (CHPRC) has recommended to the U.S. Department of Energy (DOE) a two phase approach for removal and storage (Phase 1) and treatment and packaging for offsite shipment (Phase 2) of the sludge currently stored within the 105-K West Basin. This two phased strategy enables early removal of sludge from the 105-K West Basin by 2015, allowing remediation of historical unplanned releases of waste and closure of the 100-K Area. In Phase 1, the sludge currently stored in the Engineered Containers and Settler Tanks within the 105-K West Basin will be transferred into sludge transport and storage containers (STSCs). The STSCs will be transported to an interim storage facility. In Phase 2, sludge will be processed (treated) to meet shipping and disposal requirements and the sludge will be packaged for final disposal at a geologic repository. The purpose of this study is to evaluate two alternatives for interim Phase 1 storage of K Basin sludge. The cost, schedule, and risks for sludge storage at a newly-constructed Alternate Storage Facility (ASF) are compared to those at T Plant, which has been used previously for sludge storage. Based on the results of the assessment, T Plant is recommended for Phase 1 interim storage of sludge. Key elements that support this recommendation are the following: (1) T Plant has a proven process for storing sludge; (2) T Plant storage can be implemented at a lower incremental cost than the ASF; and (3) T Plant storage has a more favorable schedule profile, which provides more float, than the ASF. Underpinning the recommendation of T Plant for sludge storage is the assumption that T Plant has a durable, extended mission independent of the K Basin sludge interim storage mission. If this assumption cannot be validated and the operating costs of T Plant are borne by the Sludge Treatment Project, the conclusions and recommendations of this study would change. The following decision-making strategy, which is

  14. Gravity Drainage of Activated Sludge on Reed Beds

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian

    from the wastewater treatment plant to the red beds may destroy the sludge structure and thereby reduces the dewaterability of sludge. Both the mechanical stress during pumping and anaerobic microbial activity affects the sludge quality. The quality of the sludge can be improved if I) the drying reed......Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...... beds are placed close to the wastewater treatment plant, II) anaerobic condition is avoid e.g. by adding calcium nitrate, and III) the sludge structure is rebuild before it is poured on the reed bed e.g. by adding calcium carbonate...

  15. Electroremediation of heavy metals in sewage sludge

    Directory of Open Access Journals (Sweden)

    C. Elicker


    Full Text Available This paper presents the application of electrokinetic remediation in the treatment of sludge in a sewage treatment station. The study consisted of, in a first step, the characterization of physicochemical parameters of sludge and, in a second step, the implementation of the electrokinetic remediation technique. The concentrations of Cu, Cr, Pb and Zn in sludge samples, before and after the experiment, were determined by atomic absorption spectroscopy. After 40 hours of experiment, considering an electrolyte flow-rate of 1.34 L.h-1 at a voltage of 20 V, the removal rate of all the metals accompanied was over 50%; the highest removal efficiency was for Pb, with 72.49%. The results show the feasibility of using the electrochemical technique of electrokinetic remediation for metal removal from a sludge sewage treatment station.

  16. Operator assisted optimization of sludge dewatering

    DEFF Research Database (Denmark)

    Grüttner, Henrik


    On a municipal wastewater treatment plant using a decanter-centrifuge for dewatering of anaerobic digested sludge an operator assisting system for sludge dewatering was developed. The system is based on a database used to collect data on sludge properties and operational conditions which is added...... by the operator. By graphical presentation and an advisory service these data are used to support the operator in his dewatering operations and to secure a running optimization of the sludge dewatering. Evaluations show that this system is a useful tool for data collection and presentation and that the data...... collected seem to reflect the actual situation at the plant. In the future such systems are expected to be used as tools for education of operators, transfer of knowledge from one operator to another and for a continuous optimization of dewatering operations. (A)...

  17. Cephalosporin-induced biliary sludge in children

    National Research Council Canada - National Science Library

    A.E. Abaturov; V.L. Babich; A.E. Lykova; A.E. Kozachkovsky; N.M. Lybenko


    ...). The purpose of the study was to establish the peculiarities of the formation of biliary sludge during the application of the third generation cephalosporins in the treatment of acute respiratory infections in children...

  18. Bacteriological studies on dairy waste activated sludge

    NARCIS (Netherlands)

    Adamse, A.D.


    Dairy-waste activated sludge was examined for bacterial composition and response to different conditions. Strains isolated were classified mainly into three groups: predominantly coryneform bacteria (largely Arthrobacter), some Achromobacteraceae and a small groups of Pseudomonadaceae.

  19. Mycological survey of activated sludge in MBRs. (United States)

    Awad, Mohamed F; Kraume, M


    The objective of this research was to conduct a survey of fungi in activated sludge plants with membrane bioreactors (MBRs). Thirty-six samples of both aerobic and anoxic activated sludge were taken from two plants with MBRs treating domestic wastewater. Over a period of 8 months, two samples from each plant were taken per month. The samples were prepared for count and identification of fungi. The obtained data show that 61 species belonging to 30 genera were identified from activated sludge samples, under aerobic conditions (27 genera and 54 species) and anoxic conditions (21 genera and 39 species), by culturing at 30 °C for 15 days. In aerobic activated sludge samples, the prevalence of Geotrichum candidum was 100% followed by Fusarium (72.2%), yeast (61.1%), Aspergillus (50.0%), Penicillium (50.0%) and Trichoderma (41.6%), while in anoxic activated sludge, G. candidum (94.4%), Fusarium (91.6%), Aspergillus (77.7%), yeast (63.8%), Penicillium (50.0%) and Trichoderma (50.0%) species were the most prevalent. In addition, the other genera found included Chaetomum, Chrysosporium, Cladosporium, Doratomyces, Gibberella, Gliocladium, Gymnoascus, Mucor, Paecilomyces, Phialophora, Rhizopus, Scopulariopsis, Stachybotrys, Stemphylium and others. The results indicate that aerobic and anoxic activated sludge provides a suitable habitat for the growth and sporulation of different groups of fungi, both saprophytic and pathogenic. © 2011 Blackwell Verlag GmbH.

  20. Gallbladder sludge: what is its clinical significance? (United States)

    Shaffer, E A


    Biliary sludge is a mixture of particulate solids that have precipitated from bile. Such sediment consists of cholesterol crystals, calcium bilirubinate pigment, and other calcium salts. Sludge is usually detected on transabdominal ultrasonography. Microscopy of aspirated bile and endoscopic ultrasonography are far more sensitive. Biliary sludge is associated with pregnancy; with rapid weight loss, particularly in the obese; with critical illness involving low or absent oral intake and the use of total parenteral nutrition (TPN); and following gastric surgery. It is also associated with biliary stones with common bile duct obstruction; with certain drugs, such as ceftriaxone and octreotide; and with bone marrow or solid organ transplantation. The clinical course of biliary sludge varies. It often vanishes, particularly if the causative event disappears; other cases wax and wane, and some go on to gallstones. Complications caused by biliary sludge include biliary colic, acute cholangitis, and acute pancreatitis. Asymptomatic patients with sludge or microlithiasis require no therapy. When patients are symptomatic or if complications arise, cholecystectomy is indicated. For the elderly or those at risk from the surgery, endoscopic sphincterotomy can prevent recurrent episodes of pancreatitis. Medical therapy is limited, although some approaches may show promise in the future.


    Energy Technology Data Exchange (ETDEWEB)

    Lee, M-J.; Lee, J-K.; Yoo, D-H.; Ho, K.


    The radiation effects on the physical characteristic of the sewage sludge were studied in order to obtain information which will be used for study on the enhancement of the sludge's dewaterability. Water contents, capillary suction time, zeta potential, irradiation dose, sludge acidity, total solid concentration, sludge particle size and microbiology before and after irradiation were investigated. Irradiation gave an effect on physical characteristics sludge. Water content in sludge cake could be reduced by irradiation at the dose of 10kGy.

  2. Application of forward osmosis (FO) under ultrasonication on sludge thickening of waste activated sludge. (United States)

    Nguyen, Nguyen Cong; Nguyen, Hau Thi; Chen, Shiao-Shing; Nguyen, Nhat Thien; Li, Chi-Wang


    Forward osmosis (FO) is an emerging process for dewatering solid-liquid stream which has the potential to be innovative and sustainable. However, the applications have still been hindered by low water flux and membrane fouling when activated sludge is used as the feed solution due to bound water from microbial cells. Hence, a novel strategy was designed to increase sludge thickening and reduce membrane fouling in the FO process under ultrasonic condition. The results from the ultrasound/FO hybrid system showed that the sludge concentration reached up to 20,400 and 28,400 mg/L from initial sludge concentrations of 3000 and 8000 mg/L with frequency of 40 kHz after 22 hours, while the system without ultrasound had to spend 26 hours to achieve the same sludge concentration. This identifies that the presence of ultrasound strongly affected sludge structure as well as sludge thickening of the FO process. Furthermore, the ultrasound/FO hybrid system could achieve NH4+-N removal efficiency of 96%, PO4(3-)-P of 98% and dissolved organic carbon (DOC) of 99%. The overall performance demonstrates that the proposed ultrasound/FO system using seawater as a draw solution is promising for sludge thickening application.

  3. Dispersed plug flow model for upflow anaerobic sludge bed reactors with focus on granular sludge dynamics

    NARCIS (Netherlands)

    Kalyuzhnyi, S.V.; Fedorovich, V.V.; Lens, P.N.L.


    A new approach to model upflow anaerobic sludge bed (UASB)-reactors, referred to as a one-dimensional dispersed plug flow model, was developed. This model focusses on the granular sludge dynamics along the reactor height, based on the balance between dispersion, sedimentation and convection using

  4. Wastewater and sludge management and research in Oman: An overview. (United States)

    Jaffar Abdul Khaliq, Suaad; Ahmed, Mushtaque; Al-Wardy, Malik; Al-Busaidi, Ahmed; Choudri, B S


    It is well recognized that management of wastewater and sludge is a critical environmental issue in many countries. Wastewater treatment and sludge production take place under different technical, economic, and social contexts, thus requiring different approaches and involving different solutions. In most cases, a regular and environmentally safe wastewater treatment and associated sludge management requires the development of realistic and enforceable regulations, as well as treatment systems appropriate to local circumstances. The main objective of this paper is to provide useful information about the current wastewater and sludge treatment, management, regulations, and research in Oman. Based on the review and discussion, the wastewater treatment and sludge management in Oman has been evolving over the years. Further, the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman. Wastewater treatment and sludge management in Oman have been evolving over the years. Sludge utilization has been a challenge due to its association with human waste. Therefore, composting of sewage sludge is the best option in agriculture activities. Sludge and wastewater utilization can add up positively in the economic aspects of the country in terms of creating jobs and improving annual income rate. The number of research projects done on wastewater reuse and other ongoing ones related to the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman.

  5. K Basin sludge treatment process description

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.


    The K East (KE) and K West (KW) fuel storage basins at the 100 K Area of the Hanford Site contain sludge on the floor, in pits, and inside fuel storage canisters. The major sources of the sludge are corrosion of the fuel elements and steel structures in the basin, sand intrusion from outside the buildings, and degradation of the structural concrete that forms the basins. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be treated so that it meets Tank Waste Remediation System (TWRS) acceptance criteria and can be sent to one of the double-shell waste tanks. The US Department of Energy, Richland Operations Office accepted a recommendation by Fluor Daniel Hanford, Inc., to chemically treat the sludge. Sludge treatment will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and reacting the solution with caustic to co-precipitate the uranium and plutonium. A truck will transport the resulting slurry to an underground storage tank (most likely tank 241-AW-105). The undissolved solids will be treated to reduce the transuranic (TRU) and content, stabilized in grout, and transferred to the Environmental Restoration Disposal Facility (ERDF) for disposal. This document describes a process for dissolving the sludge to produce waste streams that meet the TWRS acceptance criteria for disposal to an underground waste tank and the ERDF acceptance criteria for disposal of solid waste. The process described is based on a series of engineering studies and laboratory tests outlined in the testing strategy document (Flament 1998).

  6. Gas Generation from K East Basin Sludges - Series II Testing

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.


    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focused on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report will present results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge.

  7. The influence of aerobic sludge retention time on anaerobic co ...

    African Journals Online (AJOL)



    ABR) and aerobic plug flow reactor (PFR) were operated aiming to minimize excess sludge output of the activated sludge process through coupled alkaline hydrolysis and anaerobic digestion. Variations in the effluent total.

  8. The influence of aerobic sludge retention time on anaerobic co ...

    African Journals Online (AJOL)

    ABR) and aerobic plug flow reactor (PFR) were operated aiming to minimize excess sludge output of the activated sludge process through coupled alkaline hydrolysis and anaerobic digestion. Variations in the effluent total chemical oxygen ...

  9. Sewage Sludge Gasification for CHP Applications

    Energy Technology Data Exchange (ETDEWEB)

    McCahey, S.; Huang, Y.; McMullan, J.T.


    Many routes previously available for sewage sludge disposal within the European Union are now prohibited or constrained by environmental legislation. Meanwhile, sewage sludge production increases annually as more rigorous treatment processes are used. This paper introduces an ongoing project, supported by the European Commission FP5 Programme, which seeks to examine the key technical environmental and economic issues relating to the gasification of sewage sludge for utilisation in CHP applications and ultimately to establish the commercial viability of the process. Sewage sludge treatment data has been collected by country and region and a database compiled. Laboratory and pilot plant scale gasification trials are underway and two small engines and a generator have been installed and commissioned. This paper discusses the concurrent development of ECLIPSE process simulation models for the three selected gasification processes, namely fluidised bed, spouted bed and fixed bed. These models have been validated and are being used to predict the behaviour of appropriately sized commercial scale plant, enabling informed decisions regarding technical suitability. The next step in this project is to determine capital costs and economic performance. Process routes will be identified that offer the most cost effective routes to reducing environmental burdens by using sewage sludge in CHP applications. (author)

  10. Recovery of phosphorus from sewerage treatment sludge

    Energy Technology Data Exchange (ETDEWEB)

    Manuilova, Anastasia


    This thesis is a review of the current state of technologies for the removal of phosphorus from wastewater and sludge, and the recovery and re-use of phosphorus. It explains the need for phosphorus removal and describes the current removal processes. Focus is given to phosphorus crystallisation processes and to the processes which treat sewage treatment sludges into potential sources of phosphorus. An interesting possibility to recover phosphorus from sewage sludge by use of Psenner fractionation is also discussed. By this method, the following phosphate fractions of technological significance may be distinguished: (1) redox sensitive phosphates, mainly bound to Fe(OH){sub 3}; (2) phosphate adsorbed to surfaces (Al{sub 2}O{sub 3}), exchangeable against OH{sup -}, and alkali-soluble phosphate; (3) phosphate bound to CaCO{sub 3}, MgCO{sub 3} and in apatite; and (4) organically bound phosphate. The basic removal mechanisms, process schemes and treatment results are described. Two experiments with three different types of sludges from Henriksdal wastewater treatment plant in Stockholm were performed in the laboratory. It was shown that the addition of sodium hydroxide or hydrochloric acid cause the significant release of phosphate (about 80%) for all types of sludges. If a whole Psenner fractionation was performed the phosphate release is approximately 100%.

  11. EU policy on sewage sludge utilization and perspectives on new approaches of sludge management. (United States)

    Mininni, G; Blanch, A R; Lucena, F; Berselli, S


    This paper presents the current sewage sludge legislation in Europe and expected developments regarding the coming directives on the application of the "End-of-waste" criteria and on fertilizers. Discussion on sludge production and processing is also included. The Directive 86/278 has regulated the use in agriculture of residual sludge from domestic and urban wastewater. After 1986, this directive was transposed in the different member state legislation and currently the national limit values on heavy metals, some organic micropollutants and pathogens are placed in a rather wide range. This seems the inevitable consequence of different attitudes towards sludge management practices in the member states. The discussion by the European Joint Research Center (JRC) in Seville regarding application of end-of-waste criteria for compost and digestate has produced a final document (IPTS 2014) where sludge was excluded from the organic wastes admitted for producing an end-of-waste compost. Sludge processing in Europe seems addressed to different goals: sludge minimization, full stabilization and hygienization by thermal hydrolysis processes before anaerobic digestion, and on-site incineration by fluidized bed furnace. Thermophilic anaerobic digestion was applied with success on the Prague WWTP with a preliminary lysimeter centrifugation. Coming techniques, like wet oxidation and pyrolysis, are applied only on very few plants.

  12. Behavior of inorganic elements during sludge ozonation and their effects on sludge solubilization. (United States)

    Sui, Pengzhe; Nishimura, Fumitake; Nagare, Hideaki; Hidaka, Taira; Nakagawa, Yuko; Tsuno, Hiroshi


    The behavior of inorganic elements (including phosphorus, nitrogen, and metals) during sludge ozonation was investigated using batch tests and the effects of metals on sludge solubilization were elucidated. A decrease of ∼ 50% in the ratio of sludge solubilization was found to relate to a high iron content 80-120 mgFe/gSS than that of 4.7-7.4 mgFe/gSS. During sludge ozonation, the pH decreased from 7 to 5, which resulted in the dissolution of chemically precipitated metals and phosphorus. Based on experimental results and thermodynamic calculation, phosphate precipitated by iron and aluminum was more difficult to release while that by calcium released with decrease in pH. The release of barium, manganese, and chrome did not exceed 10% and was much lower than COD solubilization; however, that of nickel, copper, and zinc was similar to COD solubilization. The ratio of nitrogen solubilization was 1.2 times higher than that of COD solubilization (R(2)=0.85). Of the total nitrogen solubilized, 80% was organic nitrogen. Because of their high accumulation potential and negative effect on sludge solubilization, high levels of iron and aluminum in both sewage and sludge should be considered carefully for the application of the advanced sewage treatment process with sludge ozonation and phosphorus crystallization. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Method and apparatus for the continuous dehydration of sludge

    NARCIS (Netherlands)

    Van Poppel, E.J.M.; Rem, P.C.


    The invention relates to a method of the continuous dehydration of sludge wherein, prior to dehydration, water is mechanically removed from the sludge and the thus obtained sludge of cutting consistency is mixed with heated spheres. According to the invention dehydration is carried out at reduced

  14. A new reactor concept for sludge reduction using aquatic worms

    NARCIS (Netherlands)

    Elissen, H.J.H.; Hendrickx, T.L.G.; Temmink, B.G.; Buisman, C.J.N.


    Biological waste water treatment results in the production of waste sludge. The final treatment option in The Netherlands for this waste sludge is usually incineration. A biological approach to reduce the amount of waste sludge is through predation by aquatic worms. In this paper we test the

  15. Employing a chemical method for tubesheet sludge removal (steam generators)

    Energy Technology Data Exchange (ETDEWEB)

    Stolzenberg, N.R.; Thomas, R.C.; Thomas, R.C.


    A chemical technique has been developed for tubesheet sludge removal from PWR steam generators. The process was first applied commercially, with good results, at Millstone Point 2 where the conventional techniques of sludge lancing had not been found capable of removing sufficient sludge to arrest tube degradation.

  16. Submersible microbial fuel cell for electricity production from sewage sludge

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit


    chemical oxygen demand (TCOD) removal efficiency was 78.1±0.2% with initial TCOD of 49.7 g/L. The power generation of SMFC was depended on the sludge concentration, while dilution of the raw sludge resulted in higher power density. The maximum power density was saturated at sludge concentration of 17 g...

  17. The role of lipids in activated sludge floc formation

    Directory of Open Access Journals (Sweden)

    Anna Liza Kretzschmar


    Full Text Available Activated sludge is widely used to treat municipal and industrial wastewater globally and the formation of activated sludge flocculates (flocs underpins the ability to separate sludge from treated water. Despite the importance of activated sludge flocs to human civilization there have been precious few attempts to rationally design fit for purpose flocs using a bottom-up approach based on a solid scientific foundation. Recently we have been developing experimental models for activated sludge floc formation based on the colonization and consumption of particulate organic matter (chitin and cellulose. In this study we lay the foundation for investigation of activated sludge floc formation based on biofilm formation around spheres of the lipid glycerol trioleate (GT that form spontaneously when GT is introduced into activated sludge incubations. Sludge biomass was observed to associate tightly with the lipid spheres. An increase in extracellular lipase activity was associated with a decrease in size of the colonized lipid spheres over a 25 day incubation. Bacterial community composition shifted from predominantly Betaproteobacteria to Alphaproteobacteria in GT treated sludge. Four activated sludge bacteria were isolated from lipid spheres and two of them were shown to produce AHL like quorum sensing signal activity, suggesting quorum sensing may play a role in lipid spheres colonization and biodegradation in activated sludge. The development of this experimental model of activated sludge floc formation lays the foundation for rational production of flocs for wastewater treatment using lipids as floc nuclei and further development of the flocculate life-cycle concept.

  18. Modelling of a recycling sludge bed reactor using AQUASIM

    African Journals Online (AJOL)


    the article, it is herewith pointed out that the term “falling sludge bed reactor” is replaced with “recycling sludge bed reactor”. Modelling of a recycling sludge bed reactor using AQUASIM. NE Ristow1*, K Whittington-Jones2, C Corbett2, P Rose2 and GS Hansford1. 1 Department of Chemical Engineering, University of Cape ...

  19. Efficiency of wastewater treatment by a mixture of sludge and ...

    African Journals Online (AJOL)

    A combined system using the microalgae from South Africa and the sewage sludge from Algeria has been tested, in order to study the efficiency of wastewater treatment by mixtures of microalgae / activated sludge, five bioreactors were installed with different inoculation rates (microalgae / activated sludge) B1: 100% algae, ...

  20. Processed wastewater sludge for improvement of mechanical properties of concretes

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Diaz, Carlos, E-mail: [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Martinez-Barrera, Gonzalo [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Carretera Toluca-Atlacomulco, Km.12, San Cayetano C.P. 50200, Toluca, Edo. de Mexico (Mexico); Gencel, Osman [Civil Engineering Department, Faculty of Engineering, Bartin University, 74100 Bartin (Turkey); Bernal-Martinez, Lina A. [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Brostow, Witold [Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science and Engineering and Center for Advanced Research and Technology (CART), University of North Texas, 1150 Union Circle 305310, Denton, TX 76203-5017 (United States)


    Highlights: {yields} Electrochemical methods produce less amount of residual sludge as compared with chemical procedures. {yields} Wastewater sludge contains a large amount of water. {yields} The residual sludge is used to prepare cylinder specimen concrete. {yields} There are improvements in the elastic modulus of the concrete when is prepared with residual sludge. - Abstract: Two problems are addressed simultaneously. One is the utilisation of sludge from the treatment of wastewater. The other is the modification of the mechanical properties of concrete. The sludge was subjected to two series of treatments. In one series, coagulants were used, including ferrous sulphate, aluminium sulphate or aluminium polyhydroxychloride. In the other series, an electrochemical treatment was applied with several starting values of pH. Then, concretes consisting of a cement matrix, silica sand, marble and one of the sludges were developed. Specimens without sludge were prepared for comparison. Curing times and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and static and dynamic elastic moduli were determined. Diagrams of the compressive strength and compressive strain at the yield point as a function of time passed through the minima as a function of time for concretes containing sludge; therefore, the presence of sludge has beneficial effects on the long term properties. Some morphological changes caused by the presence of sludge are seen in scanning electron microscopy. A way of utilising sludge is thus provided together with a way to improve the compressive strain at yield point of concrete.

  1. Biological sulphate reduction with primary sewage sludge in an ...

    African Journals Online (AJOL)

    Because in operating R1 and R2, the bed volume was kept constant, the mass of sludge removed from the system correspondingly increased as upflow increased and the bed expanded, causing a reduced sludge age and sludge bed mass to mediate the bioprocesses. It was concluded that the system failure was caused ...

  2. Impact of secondary treatment types and sludge handling processes on estrogen concentration in wastewater sludge. (United States)

    Marti, Erica J; Batista, Jacimaria R


    Endocrine-disrupting compounds (EDCs), such as estrogen, are known to be present in the aquatic environment at concentrations that negatively affect fish and other wildlife. Wastewater treatment plants (WWTPs) are major contributors of EDCs into the environment. EDCs are released via effluent discharge and land application of biosolids. Estrogen removal in WWTPs has been studied in the aqueous phase; however, few researchers have determined estrogen concentration in sludge. This study focuses on estrogen concentration in wastewater sludge as a result of secondary treatment types and sludge handling processes. Grab samples were collected before and after multiple treatment steps at two WWTPs receiving wastewater from the same city. The samples were centrifuged into aqueous and solid phases and then processed using solid phase extraction. Combined natural estrogens (estrone, estradiol and estriol) were measured using an enzyme-linked immunosorbent assay (ELISA) purchased from a manufacturer. Results confirmed that activated sludge treatments demonstrate greater estrogen removal compared to trickling filters and mass concentration of estrogen was measured for the first time on trickling filter solids. Physical and mechanical sludge treatment processes, such as gravity thickeners and centrifuges, did not significantly affect estrogen removal based on mass balance calculations. Dissolved air flotation thickening demonstrated a slight decrease in estrogen concentration, while anaerobic digestion resulted in increased mass concentration of estrogen on the sludge and a high estrogen concentration in the supernatant. Although there are no state or federally mandated discharge effluent standards or sludge application standards for estrogen, implications from this study are that trickling filters would need to be exchanged for activated sludge treatment or followed by an aeration basin in order to improve estrogen removal. Also, anaerobic digestion may need to be replaced

  3. Relationship between enhanced dewaterability and structural properties of hydrothermal sludge after hydrothermal treatment of excess sludge. (United States)

    Wang, Liping; Li, Aimin; Chang, Yuzhi


    Hydrothermal treatment is an effective method to enhance the deep dewaterability of excess sludge with low energy consumption. In this study, an insight into the relationship between enhanced dewaterability and structural properties of the produced hydrothermal sludge was presented, aiming at better understanding the effect of hydrothermal process on excess sludge dewatering performance. The results indicated that hydrothermal effect induced the transformation of surface water to interstitial and free water by lowering the binding strength between adjacent water and solid particles and that free water became the main form for moisture existence in hydrothermal sludge as temperature was higher than 180 °C. Increase in temperature of hydrothermal treatment generated a significant size reduction of sludge flocs but treated sludge with a higher rigidity, which not only strengthened the network of hydrothermal sludge but also destroyed the binding of EPS with water. Hydrothermal process caused crevice and pore structures of excess sludge to disappear gradually, which was a main driving force of water removal as temperature was below 150 °C. With the temperature of hydrothermal treatment exceeding 180 °C, the morphology of hydrothermal sludge became rough which linked closely to the solid precipitation of condensation polymerization, and further became smooth at higher temperature (210 °C) due to the coal-like structures with higher aromaticities, indicating that hydrothermal reaction pathways began to play a main role in enhanced dewaterability. Hydrothermal treatment led to more alkyl and aromatic carbon, but lower O-alkyl, carboxyl and carbonyl carbon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Organics Characteristics of Sludge from a Full-Scale Anaerobic Digester Treating Domestic Mixed Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Seswoya Roslinda


    Full Text Available Sewage sludge, normally in form of mixed sewage sludge is treated using anaerobic digester worldwide. In Malaysia, sewage sludge was categorized as domestic sewage sludge since sewage treatment plant treats only domestic sewage. The complex organic compounds in form of carbohydrates and proteins are transformed to methane during anaerobic digestion. The characteristics of complex organic compounds in domestic mixed sewage sludge are needed to assess the energy recovery form digesting domestic mixed sewage sludge. Besides that, it is common to use anaerobic biomass from existing anaerobic digester for the new setup of the anaerobic reactor. Therefore, this study was outlined to study the characteristics of domestic mixed sewage sludge and anaerobic biomass, particularly on the complex organic compounds. The complex organic compounds measured were carbohydrates and proteins. The higher complex organic solubilisation as a result of thermal pre-treatment was proven to improve the methane production. Therefore, in this study, the impact of low thermal pre-treatment in improving the organics solubilisation was assessed too. Low thermal pre-treatment at 70°C and 90°C at various treatment time were applied to the domestic mixed sewage sludge. The results indicated that the domestic sewage sludge and anaerobic biomass from a full-scale anaerobic digester contained complex organic compounds; existed mostly in form of particulate as shown by the low value of soluble to total ratio. Besides that, the low thermal treatment at 70°C and 90°C increased the organics solubilisation. Protein solubilisation was observed exceeded 8% after being treated for 20 min at both thermal treatments. However, the impact of low thermal treatment was better at 90°C, in which higher solubilisation was observed at longer treatment time.

  5. Efficiency of a pilot-scale integrated sludge thickening and digestion reactor in treating low-organic excess sludge. (United States)

    He, Qiang; Li, Jiang; Liu, Hongxia; Tang, Chuandong; de Koning, Jaap; Spanjers, Henri


    The sludge production from medium- and small-scale wastewater treatment plants in the Three Gorges Reservoir Region is low and non-stable; especially, the organic content in this sludge is low (near 40% of VS/TS). An integrated thickening and digestion (ISTD) reactor was developed to treat this low-organic excess sludge. After a flow test and start-up experiment of the reactor, a running experiment was used to investigate the excess sludge treatment efficiency under five different excess sludge inflows: 200, 300, 400, 500 and 400 L/d (a mixture of excess sludge and primary sludge in a volume ratio of 9:1). This trial was carried out in the wastewater treatment plant in Chongqing, which covers 80% of the Three Gorges Reservoir Region, under the following conditions: (1) sludge was heated to 38-40 degrees C using an electrical heater to maintain anaerobic mesophilic digestion; (2) the biogas produced was recirculated to mix raw sludge with anaerobic sludge in the reactor under the flow rate of 12.5 L/min. There were three main results. Firstly, the flow pattern of the inner reactor was almost completely mixed under the air flow of 12.0 L/min using clear water. Secondly, under all the different sludge inflows, the water content in the outlet sludge was below 93%. Thirdly, the organic content in the outlet sludge was decreased from 37% to 30% and from 24% to 20%, whose removal ratio was in relation to the organic content of the inlet sludge. The excess sludge treatment capacity of the ISTD reactor was according to the organic content in the excess sludge.

  6. Determining organic pollutants in automotive industry sludge. (United States)

    Munaretto, Juliana S; Wonghon, Audrey L; von Mühlen, Carin


    In Brazil, the policy for disposing industrial sludge is changing from an emphasis on using controlled landfills to other treatment or co-processing methods; however, the monitoring of organic pollutants is not mandatory. The present study evaluated two general screening methods for organic pollutants in sludge generated in an automotive industrial complex in southern Brazil. The screening was performed using Soxhlet and sonication extractions and Gas Chromatograph coupled with Quadrupole Mass Spectrometry (GC/qMS). It was concluded that both techniques were effective and that most of the compounds identified were alkanes, phenols and esters. Important pollutants were detected in the sludge, which confirms the necessity of monitoring this type of residue.

  7. Development of a test method to access the sludge reduction potential of aquatic organisms in activated sludge

    NARCIS (Netherlands)

    Buijs, B.R.; Klapwijk, A.; Elissen, H.J.H.; Rulkens, W.H.


    This article shows the development of a quantitative sludge reduction test method, which uses the sludge consuming aquatic worm Lumbriculus variegatus (Oligochaeta, Lumbriculidae). Essential for the test are sufficient oxygen supply and the presence of a non-stirred layer of sludge for burrowing of

  8. The chemical and mechanical differences between alginate-like exopolysaccharides isolated from aerobic flocculent sludge and aerobic granular sludge

    NARCIS (Netherlands)

    Lin, Y. M.; Sharma, P. K.; van Loosdrecht, M. C. M.


    This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two

  9. Energy potential of the modified excess sludge

    Directory of Open Access Journals (Sweden)

    Zawieja Iwona


    Full Text Available On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4, it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

  10. Energy potential of the modified excess sludge (United States)

    Zawieja, Iwona


    On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4), it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

  11. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, H.K.; Kristensen, I.V.; Ottosen, L.M.; Villumsen, A. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark)


    Electroosmotic dewatering has been tested in laboratory cells for 4 different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material. Casagrande's coefficients for the three materials where determined at different water contents. In the electroosmotic experiments shown in this work chalk can be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM. The process was not optimised indicating that higher dry matter contents could be achieved. (orig.)

  12. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings

    DEFF Research Database (Denmark)

    Larsen, Julie Dam; Nielsen, Steen M; Scheutz, Charlotte


    space, the concentration of CH4 often exceeded the concentration of carbon dioxide (CO2). However, the total emission of CO2 from the surface of the sludge residue exceeded the total emission of CH4, suggesting that CO2 was mainly produced in the layer of newly applied sludge and/or that CO2 was emitted...... the resting period. As the resting period proceeded, atmospheric air re-entered the pore space at all depth levels. The methane (CH4) concentration was at its highest during the first part of the resting period, and then declined as the sludge residue became more dewatered and thereby aerated. In the pore...... from the sludge residue more readily compared to CH4....

  13. The exploitation of swamp plants for dewatering liquid sewage sludge

    Directory of Open Access Journals (Sweden)

    Jiří Šálek


    Full Text Available The operators of little rural wastewater treatment plants have been interested in economic exploitation of sewage sludge in local conditions. The chance is searching simply and natural ways of processing and exploitation stabilized sewage sludge in agriculture. Manure substrate have been obtained by composting waterless sewage sludge including rest plant biomass after closing 6–8 years period of filling liquid sewage sludge to the basin. Main attention was focused on exploitation of swamp plants for dewatering liquid sewage sludge and determination of influence sewage sludge on plants, intensity and course of evapotranspiration and design and setting of drying beds. On the base of determined ability of swamp plants evapotranspiration were edited suggestion solutions of design and operation sludge bed facilities in the conditions of small rural wastewater treatment plant.

  14. A swirling jet-induced cavitation to increase activated sludge solubilisation and aerobic sludge biodegradability. (United States)

    Mancuso, Giuseppe; Langone, Michela; Andreottola, Gianni


    In this work, a modified swirling jet induced hydrodynamic cavitation (HC) has been used for the pre-treatment of excess sludge. In order to both improve the HC treatment efficiencies and reduce the energy consumption, the effectiveness of the HC reactor on sludge disintegration and on aerobic biodegradability has been investigated at different operating conditions and parameters, such as temperature, inlet pressure, sludge total solid (TS) content and reactor geometry. The inlet pressure was related to the flow velocity and pressure drop. The best results in terms of sludge solubilisation were achieved after 2h of HC treatment, treating a 50.0gTSL -1 and using the three heads Ecowirl system, at 35.0°C and 4.0bar. Chemical and respirometric tests proved that sludge solubilisation and aerobic biodegradability can be efficiently enhanced through HC pre-treatment technique. At the optimum operating conditions, the specific supplied energy has been varied from 3276 to 12,780kJkgTS -1 in the HC treatment, by increasing the treatment time from 2 to 8 h, respectively. Low endogenous decay rates (b H ) were measured on the excess sludge at low specific supplied energy, revealing that only an alteration in floc structure was responsible for the sludge solubilisation. On the contrary, higher b H values were measured at higher specific supplied energy, indicating that the sludge solubilisation was related to a decreasing biomass viability, as consequence of dead cells and/or disrupted cells (cell lysis). Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Thornton, Brenda M.


    The Sludge Treatment Project (STP), managed for the U. S. DOE by Fluor Hanford (FH), was created to design and operate a process to eliminate uranium metal from K Basin sludge prior to packaging for Waste Isolation Pilot Plant (WIPP). The STP process uses high temperature liquid water to accelerate the reaction, produce uranium dioxide from the uranium metal, and safely discharge the hydrogen. Under nominal process conditions, the sludge will be heated in pressurized water at 185°C for as long as 72 hours to assure the complete reaction (corrosion) of up to 0.25-inch diameter uranium metal pieces. Under contract to FH, the Pacific Northwest National Laboratory (PNNL) conducted bench-scale testing of the STP hydrothermal process in November and December 2006. Five tests (~50 ml each) were conducted in sealed, un-agitated reaction vessels under the hydrothermal conditions (e.g., 7 to 72 h at 185°C) of the STP corrosion process using radioactive sludge samples collected from the K East Basin and particles/coupons of N Reactor fuel also taken from the K Basins. The tests were designed to evaluate and understand the chemical changes that may be occurring and the effects that any changes would have on sludge rheological properties. The tests were not designed to evaluate engineering aspects of the process. The hydrothermal treatment affected the chemical and physical properties of the sludge. In each test, significant uranium compound phase changes were identified, resulting from dehydration and chemical reduction reactions. Physical properties of the sludge were significantly altered from their initial, as-settled sludge values, including, shear strength, settled density, weight percent water, and gas retention.

  16. Additional paper waste in pulping sludge for biohydrogen production by heat-shocked sludge. (United States)

    Chairattanamanokorn, Prapaipid; Tapananont, Supachok; Detjaroen, Siriporn; Sangkhatim, Juthatip; Anurakpongsatorn, Patana; Sirirote, Pramote


    Dark anaerobic fermentation is an interesting alternative method for producing biohydrogen (H(2)) as a renewable fuel because of its low cost and various usable organic substrates. Pulping sludge from wastewater treatment containing plentiful cellulosic substrate could be feasibly utilized for H(2) production by dark fermentation. The objective of this study was to investigate the optimal proportion of pulping sludge to paper waste, the optimal initial pH, and the optimal ratio of carbon and nitrogen (C/N) for H(2) production by anaerobic seed sludge pretreated with heat. The pulping sludge was pretreated with NaOH solution at high temperature and further hydrolyzed with crude cellulase. Pretreatment of the pulping sludge with 3% NaOH solution under autoclave at 121 °C for 2 h, hydrolysis with 5 FPU crude cellulase at 50 °C, and pH 4.8 for 24 h provided the highest reducing sugar production yield (229.68 ± 2.09 mg/g(TVS)). An initial pH of 6 and a C/N ratio of 40 were optimal conditions for H(2) production. Moreover, the supplement of paper waste in the pulping sludge enhanced the cumulative H(2) production yield. The continuous hydrogen production was further conducted in a glass reactor with nylon pieces as supporting media and the maximum hydrogen production yield was 151.70 ml/g(TVS).

  17. Dispersed plug flow model for upflow anaerobic sludge bed reactors with focus on granular sludge dynamics. (United States)

    Kalyuzhnyi, Sergey V; Fedorovich, Vyacheslav V; Lens, Piet


    A new approach to model upflow anaerobic sludge bed (UASB)-reactors, referred to as a one-dimensional dispersed plug flow model, was developed. This model focusses on the granular sludge dynamics along the reactor height, based on the balance between dispersion, sedimentation and convection using one-dimensional (with regard to reactor height) equations. A universal description of both the fluid hydrodynamics and granular sludge dynamics was elaborated by applying known physical laws and empirical relations derived from experimental observations. In addition, the developed model includes: (1) multiple-reaction stoichiometry, (2) microbial growth kinetics, (3) equilibrium chemistry in the liquid phase, (4) major solid-liquid-gas interactions, and (5) material balances for dissolved and solid components along the reactor height. The integrated model has been validated with a set of experimental data on the start-up, operation performance, sludge dynamics, and solute intermediate concentration profiles of a UASB reactor treating cheese whey [Yan et al. (1989) Biol Wastes 27:289-305; Yan et al. (1993) Biotechnol Bioeng 41:700-706]. A sensitivity analysis of the model, performed with regard to the seed sludge characteristics and the key model parameters, showed that the output of the dispersed plug flow model was most influenced by the sludge settleability characteristics and the growth properties (especially mu(m)) of both protein-degrading bacteria and acetotrophic methanogens.

  18. Influence of Temperature, Agitation, Sludge Concentration and Solids Retention Time on Primary Sludge Fermentation

    Directory of Open Access Journals (Sweden)

    J. Sánchez Rubal


    Full Text Available The aim of this research was to determine the influence of temperature, agitation, sludge concentration, and solids retention time (SRT to obtain readily biodegradable organic matter on primary sludge (PS fermentation, which would be used as substrate in a biological nutrient removal (BNR process. Stirring and heating the sludge as well as increasing SRT improved the PS fermentation, producing a large amount of soluble chemical oxygen demand (SCOD. The influence of each operational parameter on PS hydrolysis was observed clearly. A great performance on SCOD production was obtained when the PS was stirred and heated for 3 days. However, PS concentration did not affect the fermentation. Sludge agitation is a simple process with minimal energy consumption. Warming the sludge is very interesting in those plants with anaerobic digestion, where heat energy is obtained from biogas. Therefore, PS fermentation can be improved with a minimum investment and leveraging existing resources in a wastewater treatment plant (WWTP. Fermenter volume can also be reduced if sludge is being heated and stirred during fermentation.

  19. Bacterial composition of activated sludge - importance for floc and sludge properties

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Per H.; Thomsen, Trine R.; Nielsen, Jeppe L.


    Activated sludge flocs consist of numerous constituents which, together with other factors, are responsible for floc structure and floc properties. These properties largely determine the sludge properties such as flocculation, settling and dewaterability. In this paper we briefly review the present knowledge about the role of bacteria in relation to floc and sludge properties, and we present a new approach to investigate the identity and function of the bacteria in the activated sludge flocs. The approach includes identification of the important bacteria and a characterization of their physiological and functional properties. It is carried out by use of culture-independent molecular biological methods linked with other methods to study the physiology and function maintaining a single cell resolution. Using this approach it was found that floc-forming properties differed among the various bacterial groups, e.g. that different microcolony-forming bacteria had very different sensitivities to shear and that some of them deflocculated under anaerobic conditions. in our opinion, the approach to combine identity with functional analysis of the dominant bacteria in activated sludge by in situ methods is a very promising way to investigate correlations between presence of specific bacteria, and floc and sludge properties that are of interest. (author)

  20. Bacterial regrowth potential in alkaline sludges from open-sun and covered sludge drying beds

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, U.; Topac, F.O.; Birden, B.; Baskaya, H.S. [Uludag University, Gorukle (Turkey). Dept. of Environmnetal Engineering


    The aim of this study was to compare the regrowth potentials of wastewater sludges dried in two pilot-scale drying processes namely, Open-Sun Sludge Drying Bed (OSDB) and Covered Sludge Drying Bed (CSDB). Quicklime and/or coal fly ash were added to raw sludge samples prior to drying processes in order to enhance bacterial inactivation. Following three drying cycles (March-April, June-July and August-October), sludge samples were taken from the beds for the regrowth experiments. Addition of alkaline materials prevented the regrowth of faecal coliforms in all rewetted samples except for the samples obtained after the rainfall events in OSDB. Rewetting of these samples in the regrowth experiments increased faecal coliform numbers by 3.5-7 log units. In contradiction, the observed bacterial numbers in rewetted alkaline samples from CSDB were below the EPA Class B criterion (2 million MPN g{center_dot} 1) dry sludge). The combination of additional heat from solar collectors, protection from the rain and the unfavourable living conditions owing to alkaline materials appeared to inactivate bacteria more effectively in CSDB and hence eliminated regrowth potential more efficiently.

  1. Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw (United States)

    Wang, Laifu; Wang, Yan; Lian, Jingyan


    Urban sewage sludge with complicated composition produce largely each year, pollution problem and resource utilization has increasingly become the focus of attention. Sewage sludge is utilized to prepare adsorbent that is a new type method. Agricultural stalks was added to material (urban sewage sludge) and activator (ZnCl2), calcined under the condition of no inert gas, and obtained domestic sludge activated carbon. The properties were measured by iodine adsorption value and BET, discussed influence factors of sludge activated carbon preparation, including activator concentration, solid-liquid ratio, calcific temperature and calcific time. The best process condition of orthogonal experiment had explored that activated time is 10 minutes, calcific temperature is 350°C, the activator concentration ZnCl2 is 3 mol/L and the mixing ratio of raw materials and activator is approximately 1:5. The iodine adsorption value and the optimal BET of as-obtained domestic sludge activated carbon is 445.06 mg/g, 525.31m2/g, respectively.

  2. Regulation of aerobic granular sludge reformulation after granular sludge broken: effect of poly aluminum chloride (PAC). (United States)

    Liu, Yongjun; Liu, Zhe; Wang, Fukun; Chen, Yiping; Kuschk, Peter; Wang, Xiaochang


    The present study focuses on the effect of poly aluminum chloride (PAC) on the re-formation of aerobic granular sludge after its rupture. The morphological changes, physical characteristics such as SVI, mechanical strength and surface properties of aerobic granular sludge during the re-formation process of broken granules were investigated. Moreover, components (protein (PN), polysaccharides (PS)) and distributions (soluble, loosely-bound (LB), tightly-bound (TB)) of extracellular polymeric substances (EPS) in sludge flocs were taken into consideration. It was found that the effect of charge neutralization and bridging induced by PAC treatment improved the surface properties of sludge, the re-formed granules had a larger size, more compact structure and that the removal performance of pollutants after chemical coagulation had improved. The results of correlation analysis demonstrated that PN in EPS correlated well with the surface characteristics and settling ability of sludge flocs, and PAC treatment strengthened the influence, further accelerated the reformation of granular sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Sorption of perfluoroalkyl substances in sewage sludge. (United States)

    Milinovic, Jelena; Lacorte, Silvia; Rigol, Anna; Vidal, Miquel


    The sorption behaviour of three perfluoroalkyl substances (PFASs) (perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonic acid (PFBS)) was studied in sewage sludge samples. Sorption isotherms were obtained by varying initial concentrations of PFOS, PFOA and PFBS. The maximum values of the sorption solid-liquid distribution coefficients (Kd,max) varied by almost two orders of magnitude among the target PFASs: 140-281 mL g(-1) for PFOS, 30-54 mL g(-1) for PFOA and 9-18 mL g(-1) for PFBS. Freundlich and linear fittings were appropriate for describing the sorption behaviour of PFASs in the sludge samples, and the derived KF and Kd,linear parameters correlated well. The hydrophobicity of the PFASs was the key parameter that influenced their sorption in sewage sludge. Sorption parameters and log(KOW) were correlated, and for PFOS (the most hydrophobic compound), pH and Ca + Mg status of the sludge controlled the variation in the sorption parameter values. Sorption reversibility was also tested from desorption isotherms, which were also linear. Desorption parameters were systematically higher than the corresponding sorption parameters (up to sixfold higher), thus indicating a significant degree of irreversible sorption, which decreased in the sequence PFOS > PFOA > PFBS.

  4. Utilization of sludge in building material

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Nagaharu; Ishikawa, Yoshinori; Shimizu, Aya; Yoshida, Mitsuhiro


    Several thermal solidification processes have been developed mainly in Japan. They are lightweight aggregates, brick, interlocking tile, char, and slag. A full-scale plant of them has been successfully operated for more than 10 years. The quality of the end products is better than the traditional ones. They are all substitutive to existing ones. The Japanese experience proves that all the processes are technically feasible, but not economically. Their manufacturing cost is always higher than market price. In addition, they consume large amount of energy. However, if they are identified for a process of sludge disposal, all of them are worth considering for a big city where is no place for the sludge to go. The end products can be reused inside the city. A new alternative is ''Portland cement''. A Portland cement manufacturer accepts sewage sludge, If being paid some amount of money. An average payment is US$100 each 1000 kg of ash or sludge cake. The Portland cement manufacturer accepts either cake or ash at the same price. It is about 50 to 30 % of the energy cost of thermal solidification. A question is ''which is better, dewatered cake or incinerated ash, for the Portland cement application''. An answer is ''it depends on a distance between a sewage plant and a Portland cement plant''. (author)

  5. Digested sewage sludge gasification in supercritical water. (United States)

    Zhai, Yunbo; Wang, Chang; Chen, Hongmei; Li, Caiting; Zeng, Guangming; Pang, Daoxiong; Lu, Pei


    Digested sewage sludge gasification in supercritical water was studied. Influences of main reaction parameters, including temperature (623-698 K), pressure (25-35 Mpa), residence time (10-15 min) and dry matter content (5-25 wt%), were investigated to optimize the gasification process. The main gas products were methane, carbon monoxide, carbon dioxide and traces of ethene, etc. Results showed that 10 wt% dry matter content digested sewage sludge at a temperature of 698 K and residence time of 50 min, with a pressure of 25 MPa, were the most favorable conditions for the sewage sludge gasification and carbon gasification efficiencies. In addition, potassium carbonate (K2CO3) was also employed as the catalyst to make a comparison between gasification with and without catalyst. When 2.6 g K2CO3 was added, a gasification efficiency of 25.26% and a carbon gasification efficiency of 20.02% were achieved, which were almost four times as much as the efficiencies without catalyst. K2CO3 has been proved to be effective in sewage sludge gasification.

  6. Phosphorus Recovery from Ashes of Sewage Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cornel, Peter; Schaum, Peter


    About 90% of the incoming phosphorus load of waste water is eliminated by waste water treatment and transferred into the sewage sludge. Considerable amounts of sewage sludge can not be used agriculturally but are incinerated. Thus the ash from mono sludge incineration plants contains significant amounts of phosphorus (up to 25% P{sub 2}O{sub 5}) and could be used as raw material in fertilizer industry. The ash is hygienically harmless and free of organic substances. The ratio of phosphorus to heavy metals is basically the same as in the sewage sludge. The first step in separating phosphorus from heavy metals is to dissolve phosphorus by extraction. The most promising way seems to be the release of phosphorus with acids or bases. With 1 m sulphuric acid it is possible to release phosphorus completely. By use of acid most of the heavy metals dissolve, too. With caustic soda as solvent, only 30-40% of the phosphorus can be dissolved but the eluate is almost free of heavy metals. The amount of phosphorus which can be released with caustic soda, depends on the applied precipitant (Al or Fe salts) for phosphorus elimination at the waste water treatment. (author)

  7. Parasites in soil/sludge systems

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, J.R.


    The potential for the transmission of parasites, such as Entamoeba sp., schistosomes, and nematodes such as Ascaris sp., to man through the use of sewage sludges as fertilizer is reviewed. The eggs of Ascaris have been found to be the most resistant of these parasites to normal sludge treatment methods. Results of studies on the effectiveness of heat and ionizing radiation treatments reported show that a treatment of 55/sup 0/C for 1 hour or more sufficiently reduces the number of viable Ascaris eggs in seeded sludge systems. An absorbed dose of 300 kilorads radiation is more than adequate for the same purpose. However, before an unequivocal statement can be made about the effectiveness of either of these treatments in reducing viable ova in real systems, certain qualifying factors must be investigated. There are conflicting reports on the radiation sensitivities of Ascaris eggs in different stages of development. Also, irradiation of composted sludge using an electron beam was unsuccessful in rendering all naturally-occurring Ascaris ova non-viable, even at 300 kilorads. The significant differences in radiation and heat sensitivities of Ascaris eggs in compost vs liquid systems points out the need to further investigate the effects of moisture levels on these sensitivities.


    African Journals Online (AJOL)


    Ife Journal of Science. (2017) vol. 19, no. 1. PHYTOEXTRACTION ... of heavy metals absorbed by the vegetable were insignificant when compared to the amount remaining in the soil. Key Words: Sewage sludge, Green amaranth, ..... International Journal of Geology5(1): 14-20. Bada, B. S., Arowolo, T. A. and Ozoike, P. N., ...

  9. Phosphorous source sewage sludge; Phosphorquelle Klaerschlamm

    Energy Technology Data Exchange (ETDEWEB)

    Scheidig, Klaus [DWA, Kaulsdorf (Germany); Mallon, Joachim; Schaaf, Michael [ingitec, Leipzig (Germany)


    Modern forms of the utilization of sewage sludge should consider an energetic and material use. This requirement is realized with the Mephrec procedure. For this, a German large city arranged a feasibility study. The contribution under consideration presents the procedure before being implemented in the practice.

  10. Contextual investigation of factors affecting sludge accumulation ...

    African Journals Online (AJOL)

    Pit latrines in slums areas of Uganda fill up faster than might be expected from some estimates owing to inappropriate use and failure to consider critical factors affecting sludge accumulation rates at the planning, design and construction stages. This study sought to investigate factors affecting filling rates of lined pit latrines ...

  11. Contextual investigation of factors affecting sludge accumulation ...

    African Journals Online (AJOL)

    ABSTRACT. Pit latrines in slums areas of Uganda fill up faster than might be expected from some estimates owing to inappropriate use and failure to consider critical factors affecting sludge accumulation rates at the planning, design and construction stages. This study sought to investigate factors affecting filling rates of ...

  12. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, Sascha R.A.; Kootstra, A.M.J.


    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching

  13. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.


    of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...

  14. Development and Design of Sludge Freezing Beds (United States)


    the Buchner funnel. This made it difficult to take a representative sludge sample. To avoid this problem the solids content (after drainage) C. James Martel. Han - over, N.H.: U.S. Army Cold Regions Research and Engineering Laboratory; Springfield, Va.: available from National Technical

  15. Wastewater and Sludge Reuse Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Ioannis K. Kalavrouziotis


    Full Text Available Huge quantities of treated wastewater (TMWW and biosolids (sludge are produced every day all over the world, which exert a strong pressure on the environment. An important question that is raised is “what to do with them?”.An effort is put by the scientific community to eliminate the concept of “waste” and to replace it with the concept of “recycling of resources”, by means of effective management, which does not concern only the users, but all the other groups involved in the problem, such as facility administrators, operations, politicians, scientific community and the general population. Sludge concentration data showed that there exist 516 chemicals in biosolids which create a serious health risk. It is pointed out that this risk will be greatly exacerbated by chemical toxins present in the sludge which can predispose skin to infection by pathogens. Consequently, the need for science-based policies are necessary to effectively protect public health. The risk assessment due to sludge, is difficult to evaluate of due to the large number of unknown interactions involved. People living near the sludge application sites may suffer from such abnormalities as: eye, nose, and throat irritation, gastrointestinal abnormalities, as nausea, vomiting, diarrhea, including cough, difficulty in breathing, sinus congestion, skin infection and sores. Many problems seem to be related to biosolid and wastewater application in agriculture, which should be solved. A universal one, acknowledged as an “international health crisis” is the resistance of pathogens to antibiotics and to the evolution of multidrug resistance of bacteria”. Certain anthropogenically created environments have been identified as major sources of multidrug resistance bacteria such as in water treatment plants, concentrated animal feeding operations etc. All these, and many other health problems, render the safety of sludge and biosolid and wastewater agricultural reuse, for

  16. Plant-soil interactions of sludge-borne heavy metals and the effect ...

    African Journals Online (AJOL)



    Jan 1, 2001 ... anaerobic digested sludge and thickened waste-activated domestic sludge) ... digestion used to digest sediments, sludges, and soil samples. This .... Sand. Loam. Clay. South African sludge guidelines when the metal concentrations in sludges are expressed as total metal content (EPA method 3050), and.

  17. Combustion characteristics of biodried sewage sludge. (United States)

    Hao, Zongdi; Yang, Benqin; Jahng, Deokjin


    In this study, effects of biodrying on the characteristics of sewage sludge and the subsequent combustion behavior were investigated. 7-Day of biodrying removed 49.78% of water and 23.17% of VS initially contained in the sewage sludge and increased lower heating value (LHV) by 37.87%. Meanwhile, mass contents of C and N decreased from 36.25% and 6.12% to 32.06% and 4.82%, respectively. Surface of the biodried sewage sludge (BDSS) appeared granulated and multi-porous, which was thought to facilitate air transfer during combustion. According to thermogravimetric (TG) analysis coupled with mass spectrometer (MS) with a heating rate of 10 °C/min from 35 °C to 1000 °C, thermally-dried sewage sludge (TDSS) and BDSS lost 74.39% and 67.04% of the initial mass, respectively. In addition, combustibility index (S) of BDSS (8.67 × 10 -8  min -2  K -3 ) was higher than TDSS. TG-MS analyses also showed that less nitrogenous gases were generated from BDSS than TDSS. It was again showed that the average CO and NO concentrations in exit gas from isothermal combustion of BDSS were lower than those from TDSS, especially at low temperatures (≤800 °C). Based on these results, it was concluded that biodrying of sewage sludge was an energy-efficient water-removal method with less emission of air pollutants when BDSS was combusted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Screw pyrolysis technology for sewage sludge treatment. (United States)

    Tomasi Morgano, Marco; Leibold, Hans; Richter, Frank; Stapf, Dieter; Seifert, Helmut


    Sewage sludge quantities have grown continuously since the introduction of the European Directive (UWWTD 91/271/EEC) relating to the treatment of urban wastewater. In the present, most of the sewage sludge is combusted in single fuels incineration plants or is co-fired in waste incineration or coal power plants. The combustion of sewage sludge is a proven technology. Other treatments, such as fluidized bed gasification, were successfully adopted to produce suitable syngas for power production. Besides, the number of large wastewater treatment plants is relatively small compared to the local rural ones. Moreover, alternative technologies are arising with the main target of nutrients recovery, with a special focus on phosphorus. The aforementioned issues, i.e. the small scale (below 1MW) and the nutrients recovery, suggest that pyrolysis in screw reactors may become an attractive alternative technology for sewage sludge conversion, recovery and recycling. In this work, about 100kg of dried sewage sludge from a plant in Germany were processed at the newly developed STYX Reactor, at KIT. The reactor combines the advantages of screw reactors with the high temperature filtration, in order to produce particle and ash free vapors and condensates, respectively. Experiments were carried out at temperatures between 350°C and 500°C. The yield of the char decreased from 66.7wt.% to 53.0wt.%. The same trend was obtained for the energy yield, while the maximum pyrolysis oil yield of 13.4wt.% was obtained at 500°C. Besides mercury, the metals and the other minerals were completely retained in the char. Nitrogen and sulfur migrated from the solid to the condensate and to the gas, respectively. Based on the energy balance, a new concept for the decentral production of char as well as heat and power in an externally fired micro gas turbine showed a cogeneration efficiency up to about 40%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Pre-treatment of tannery sludge for sustainable landfilling. (United States)

    Alibardi, Luca; Cossu, Raffaello


    The wastewater produced during tanning activities are commonly conveyed to centralised industrial wastewater treatment plants. Sludge from physical-chemical treatments (i.e. primary sedimentation) and waste activated sludge from biological treatment units are called tannery sludge. Tannery sludge is a solid waste that needs to be carefully managed and its disposal represents one of the major problems in tannery industry. Conventional treatment and disposal of tannery sludge are based mainly on incineration and landfilling. The aim of this study was to evaluate the effects of a pre-treatment process composed of aerobic stabilisation, compaction and drying, for a sustainable landfilling of tannery sludge. The process produced a reduction of volume, mass and biodegradability of treated sludge. Results also demonstrated a reduced leachability of organic and inorganic compounds from treated sludge. The pre-treatment process could allow to extend landfill life time due to lower amounts of tannery sludge to be disposed off, minimise long terms landfill emissions and obtain a state of carbon sink for tannery sludge landfilling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Fiscal year 1994 1/25-scale sludge mobilization testing

    Energy Technology Data Exchange (ETDEWEB)

    Powell, M.R.; Gates, C.M.; Hymas, C.R.; Sprecher, M.A. [Pacific Northwest Lab., Richland, WA (United States); Morter, N.J. [Associated Western Universities, Inc., Salt Lake City, UT (United States). Northwest Div.


    There are 28 one-million-gallon double-shell radioactive waste tanks on the Hanford Reservation in southeastern Washington State. The waste in these tanks was generated during processing of nuclear materials. Solids-laden slurries were placed into many of the tanks. Over time, the waste solids have settled to form a layer of sludge in the bottom of these tanks. The sludge layer thickness varies from tank to tank with some having only a few centimeters or no sludge up to some tanks which have about 4.5 m (15 ft) of sludge. It is planned that the waste will be removed from these tanks as part of the overall Hanford site cleanup efforts. Jet mixer pumps are to be placed into the tanks to stir up (mobilize) the sludge and form a uniform slurry suitable for pumping to downstream processing facilities. These mixer pumps use powerful jets of tank fluid directed horizontally out of two, diametrically opposed nozzles near the tank bottom. These fluid jets impinge upon the sludge and stir it up. The amount of sludge mobilized by the mixer pump jets depends not only on the jet properties, but also on the ability of the sludge to resist the jets. It is the goal of the work described in this document to develop the ability to predict how much sludge will be mobilized by the mixer pumps based on the size and velocity of the mixer pump jets and the physical and chemical properties of the tank sludge.

  1. Optimization of dairy sludge for growth of Rhizobium cells. (United States)

    Singh, Ashok Kumar; Singh, Gauri; Gautam, Digvijay; Bedi, Manjinder Kaur


    In this study dairy sludge was evaluated as an alternative cultivation medium for Rhizobium. Growth of bacterial strains at different concentrations of Dairy sludge was monitored. Maximum growth of all strains was observed at 60% Dairy sludge concentration. At 60% optical density (OD) values are 0.804 for Rhizobium trifolii (MTCC905), 0.825 for Rhizobium trifolii (MTCC906), and 0.793 for Rhizobium meliloti (MTCC100). Growth pattern of strains was observed at 60% Dairy sludge along with different synthetic media (tryptone yeast, Rhizobium minimal medium and yeast extract mannitol). Growth in 60% Dairy sludge was found to be superior to standard media used for Rhizobium. Media were optimized using 60% dairy sludge along with different concentrations of yeast extract (1-7 g/L) and mannitol (7-13 g/L) in terms of optical density at different time intervals, that is, 24, 48 and 72 hours. Maximum growth was observed in 6 g/L of yeast extract and 12 g/L of mannitol at 48-hour incubation period in all strains. The important environmental parameters such as pH were optimized using 60% dairy sludge, 60% dairy sludge +6 g/L yeast extract, and 60% dairy sludge +12 g/L mannitol. The maximum growth of all strains was found at pH 7.0. The present study recommends the use of 60% dairy sludge as a suitable growth medum for inoculant production.

  2. Effect of sludge behavior on performance of centrifugal contactor

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, A.; Sano, Y.; Takeuchi, M. [Japan Atomic Energy Agency - JAEA, 4-33 Muramatsu Tokai-mura Naka-gun Ibaraki-pref. 319-1194 (Japan)


    The Japan Atomic Energy Agency has been developing an annular centrifugal contactor for solvent extraction in spent fuel reprocessing, which allows the mixing of aqueous and organic phases in the annular area and their separation from the mixed phase in the rotor. The effects of sludge behavior on the performance of a centrifugal contactor were investigated. Sludge accumulation during the operation of the centrifugal contactor was observed only in the rotor. Based on the sludge accumulation behavior, the effects of rotor sludge accumulation on the performance of phase separation and extraction were investigated using several types of rotors, which simulated different sludge accumulation levels in the separation area. It was confirmed that rotor sludge accumulation would affect the phase separation performance but not the extraction performance. This can be explained by the structure of the centrifugal contactor, wherein the extraction reaction and phase separation mainly proceed in the housing and rotor, respectively.

  3. Solubilization and Elimination of Coliforms from Sewage Sludge by Sonication. (United States)

    Pathki, Snehal; Kumar, M Suresh; Vaidya, A N


    Disposal of sewage secondary excess sludge is a great problem globally, and stabilization of this excess sludge by anaerobic digestion is hampered due to its constituents resistant to biodegradation. Sludge pre-treatment enhances the performance of anaerobic digestion. In this study, sewage sludge was collected from a full-scale sewage treatment plant and characterized. Ultrasonic method was used for the excess sludge disintegration of microbial flocks and cells, so as to breakdown the intracellular or extracellular polymeric materials to enhance the anaerobic digestion. The studies related to the effect of sonication on release of nutrients, increase in soluble COD and reduction in pathogenic coliforms as well as heterotrophic microorganisms and the optimization of sonication time were carried out. The results showed that the twenty minutes sonication (25 kHz) increased the soluble COD content, nutrient release and complete disappearance of fecal as well as total coliforms in the treated sludge. The results are presented and discussed in this paper.

  4. Economic assessment of sludge handling and environmental impact of sludge treatment in a reed bed system. (United States)

    Nielsen, Steen


    The effect on the environment of the establishment and operation of a sludge treatment reed bed system (STRB) is quite limited compared to mechanical sludge dewatering, with its accompanying use of energy and chemicals. The assessment presented here of the investment, operation and maintenance costs of a typical STRB, and of the related environmental impact, is based on the experiences gained from the operation of a large number of STRB in Denmark. There are differences in the environmental perspectives and costs involved in mechanical sludge dewatering and disposal on agricultural land compared to STRB. The two treatment methods were considered for comparison based on a treatment capacity of 550 tons of dry solids per year and with land application of the biosolids in Denmark. The initial capital cost for STRB is higher than a conventional mechanical system; however, an STRB would provide significant power and operating-cost savings, with a significant saving in the overall cost of the plant over 20-30 years. The assessment focuses on the use of chemicals, energy and greenhouse gas emissions and includes emptying, sludge residue quality and recycling. STRB with direct land application is the most cost-effective scenario and has the lowest environmental impact. A sludge strategy consisting of an STRB will be approximately DKK 536,894-647,636 cheaper per year than the option consisting of a new screw press or decanter.

  5. A systematic study of the gaseous emissions from biosolids composting: raw sludge versus anaerobically digested sludge. (United States)

    Maulini-Duran, Caterina; Artola, Adriana; Font, Xavier; Sánchez, Antoni


    Volatile organic compound (VOC) and ammonia, that contribute to odor pollution, and methane and nitrous oxide, with an important greenhouse effect, are compounds present in gaseous emission from waste treatment installations, including composting plants. In this work, gaseous emissions from the composting of raw (RS) and anaerobically digested sludge (ADS) have been investigated and compared at pilot scale aiming to provide emission factors and to identify the different VOC families present. CH4 and N2O emissions were higher in ADS composting (0.73 and 0.55 kg Mg(-1) sludge, respectively) than in RS composting (0.01 kg Mg(-1) sludge for both CH4 and N2O). NH3 and VOCs emitted were higher during the RS composting process (19.37 and 0.21 kg Mg(-1) sludge, respectively) than in ADS composting (0.16 and 0.04 kg Mg(-1) sludge). Significant differences were found in the VOC compositions emitted in ADS and RS composting, being more diverse in RS than ADS composting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus


    Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct...... and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast...

  7. Reduction in Ammonium Ions in Sludge Liquor

    Directory of Open Access Journals (Sweden)

    Eglė Šlajūtė


    Full Text Available Liquor rejected from the centrifugation of the digested sludge can contain the concentrations of ammonium ions up to 1750 mg/L. These loads are usually returned to the intake of wastewater treatment plants (WWTP without additional treatment and can have a negative impact on biological wastewater and/or sludge treatment processes, e.g. phosphorus and nitrogen removal. This article deals with the use of naturally obtained sorbent, zeolite, in batch and column test procedure for removing ammonium from the rejected liquor. This research study was carried out using different sizes of zeolite particles: 0.8–1.6 mm and 1.6–2.5 mm. The highest efficiency of ammonium removal (up to 98 % was achieved by applying the zeolite particles of 0.8–1.6 mm.Article in Lithuanian

  8. Laboratory tests of sludge-control additives

    Energy Technology Data Exchange (ETDEWEB)

    Tatnall, R.E. [MIC Associates, Inc., Chadds Ford, PA (United States)


    Laboratory {open_quotes}jar{close_quotes} tests compared eleven different fuel oil and diesel fuel sludge-control additives. Factors studied included (1) ability to disperse and prevent buildup of sludge deposits on surfaces, (2) ability to protect steel from corrosion, (3) ability to inhibit growth and proliferation of bacteria, and (4) ability to disperse water. Results varied greatly, and it was found that many commercial products do not do what they claim. It is concluded that fuel retailers should not believe manufacturers` claims for their additive products, but rather should test such products themselves to be sure that the benefits of treatment are real. A simplified form of the procedure used here is proposed as one way for dealers to do such testing.

  9. Impact of sludge stabilization processes and sludge origin (urban or hospital) on the mobility of pharmaceutical compounds following sludge landspreading in laboratory soil-column experiments. (United States)

    Lachassagne, Delphine; Soubrand, Marilyne; Casellas, Magali; Gonzalez-Ospina, Adriana; Dagot, Christophe


    This study aimed to determine the effect of sludge stabilization treatments (liming and anaerobic digestion) on the mobility of different pharmaceutical compounds in soil amended by landspreading of treated sludge from different sources (urban and hospital). The sorption and desorption potential of the following pharmaceutical compounds: carbamazepine (CBZ), ciprofloxacin (CIP), sulfamethoxazole (SMX), salicylic acid (SAL), ibuprofen (IBU), paracetamol (PAR), diclofenac (DIC), ketoprofen (KTP), econazole (ECZ), atenolol (ATN), and their solid-liquid distribution during sludge treatment (from thickening to stabilization) were investigated in the course of batch testing. The different sludge samples were then landspread at laboratory scale and leached with an artificial rain simulating 1 year of precipitation adapted to the surface area of the soil column used. The quality of the resulting leachate was investigated. Results showed that ibuprofen had the highest desorption potential for limed and digested urban and hospital sludge. Ibuprofen, salicylic acid, diclofenac, and paracetamol were the only compounds found in amended soil leachates. Moreover, the leaching potential of these compounds and therefore the risk of groundwater contamination depend mainly on the origin of the sludge because ibuprofen and diclofenac were present in the leachates of soils amended with urban sludge, whereas paracetamol and salicylic acid were found only in the leachates of soils amended with hospital sludge. Although carbamazepine, ciprofloxacin, sulfamethoxazole, ketoprofen, econazole, and atenolol were detected in some sludge, they were not present in any leachate. This reflects either an accumulation and/or (bio)degradation of these compounds (CBZ, CIP, SMX, KTP, ECZ, and ATN ), thus resulting in very low mobility in soil. Ecotoxicological risk assessment, evaluated by calculating the risk quotients for each studied pharmaceutical compound, revealed no high risk due to the

  10. Sustainable Development of Sewage Sludge-to-Energy in China

    DEFF Research Database (Denmark)

    Ren, Jingzheng; Liang, Hanwei; Dong, Liang


    proposed. After the grey DEMATEL analysis, a grey Multi-Criteria Decision Making (MCDM) framework which allows multiple decision-makers/stakeholders to use linguistic terms to participate in the decision-making for prioritizing the alternative technologies for sludge-to-energy was developed......In order to promote the sustainable development of sludge-to-energy industry and help the decision-makers/stakeholders to select the most sustainable technology for achieving the sludge-to-energy target, this study aims at using grey Decision Making Trial and Evaluation Laboratory (DEMATEL...... is feasible for group decision-making and sustainability assessment of the alternative technologies for sludge-to-energy....

  11. Digital image processing and analysis for activated sludge wastewater treatment. (United States)

    Khan, Muhammad Burhan; Lee, Xue Yong; Nisar, Humaira; Ng, Choon Aun; Yeap, Kim Ho; Malik, Aamir Saeed


    Activated sludge system is generally used in wastewater treatment plants for processing domestic influent. Conventionally the activated sludge wastewater treatment is monitored by measuring physico-chemical parameters like total suspended solids (TSSol), sludge volume index (SVI) and chemical oxygen demand (COD) etc. For the measurement, tests are conducted in the laboratory, which take many hours to give the final measurement. Digital image processing and analysis offers a better alternative not only to monitor and characterize the current state of activated sludge but also to predict the future state. The characterization by image processing and analysis is done by correlating the time evolution of parameters extracted by image analysis of floc and filaments with the physico-chemical parameters. This chapter briefly reviews the activated sludge wastewater treatment; and, procedures of image acquisition, preprocessing, segmentation and analysis in the specific context of activated sludge wastewater treatment. In the latter part additional procedures like z-stacking, image stitching are introduced for wastewater image preprocessing, which are not previously used in the context of activated sludge. Different preprocessing and segmentation techniques are proposed, along with the survey of imaging procedures reported in the literature. Finally the image analysis based morphological parameters and correlation of the parameters with regard to monitoring and prediction of activated sludge are discussed. Hence it is observed that image analysis can play a very useful role in the monitoring of activated sludge wastewater treatment plants.

  12. Influences of Different Conditioners on Dehydration Ratio of Activated Sludge (United States)

    Zhuo, Qiongfang; Zheng, Wenli; Yi, Hao; Chen, Sili; Xu, Zhencheng; Jin, Zhong; Lan, Yongzhe; Guo, Qingwei


    Excess sludge contains a large quantity of water with water content reaching about 97%-99%. Besides microorganisms and germs, the sludge is of complicated composition, including heavy metals, persistent organic pollutants, PPCPs, endocrine disrupters, etc. It covers a large area with harmfulness, so it needs further treatment. However, due to existence of extracellular polymeric substances in the sludge, the sludge has poor dehydration property, so how to improve dehydration of sludge is a difficult point in water treatment industry. Chemical conditioning—mechanical dehydration method is sludge dehydration technology which has been widely applied in China. Most sludge treatment plants use organic and inorganic conditioners like polyacrylamide (PAM), polyaluminum chloride (PAC) and polymerized ferrous sulfate (PFS), etc. With characteristics of low toxicity and degradation resistance, these conditioners pose potential risks to the environment and they are adverse to follow-up resource utilization. Therefore, influences of 17 conditioners on sludge dehydration ratio were discussed in this paper, expecting to seek for green, environmentally friendly and highly efficient conditioner so as to improve resource utilization ratio of sludge.

  13. On-line Measurements of Settling Charateristics in Activated Sludge

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben


    An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose...... was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The result were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity......, which was not apparent in the DSVI (Diluted Sludge Volume Index)....

  14. Recovery of indigenous enteroviruses from raw and digested sewage sludges. (United States)

    Goddard, M R; Bates, J; Butler, M


    We examined different types of raw sewage sludge treatment, including consolidation, anaerobic mesophilic digestion with subsequent consolidation, and aerobic-thermophilic digestion. Of these, the most efficient reduction in infectious virus titer was achieved by mesophilic digestion with subsequent consolidation, although a pilot-scale aerobic-thermophilic digester was extremely time effective, producing sludges with similarly low virus titers in a small fraction of the time. Although none of the treatments examined consistently produced a sludge with undetectable virus levels, mesophilic digestion alone was found to be particularly unreliable in reducing the levels of infectious virus present in the raw sludge.

  15. Properties of wastepaper sludge in geopolymer mortars for masonry applications. (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi


    This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Supercritical water oxidation treatment of textile sludge. (United States)

    Zhang, Jie; Wang, Shuzhong; Li, Yanhui; Lu, Jinling; Chen, Senlin; Luo, XingQi


    In this work, we studied the supercritical water oxidation (SCWO) of the textile sludge, the hydrothermal conversion of typical textile compounds and the corrosion properties of stainless steel 316. Moreover, the influence mechanisms of NaOH during these related processes were explored. The results show that decomposition efficiency for organic matter in liquid phase of the textile sludge was improved with the increment of reaction temperature or oxidation coefficient. However, the organic substance in solid phase can be oxidized completely in supercritical water. Serious coking occurred during the high pressure water at 250-450°C for the Reactive Orange 7, while at 300 and 350°C for the polyvinyl alcohol. The addition of NaOH not only accelerated the destruction of organic contaminants in the SCWO reactor, but effectively inhibited the dehydration conversion of textile compounds during the preheating process, which was favorable for the treatment system of textile sludge. The corrosion experiment results indicate that the stainless steel 316 could be competent for the body materials of the reactor and the heat exchangers. Furthermore, there was prominent enhancement of sodium hydroxide for the corrosion resistance of 316 in subcritical water. On the contrary the effect was almost none during SCWO.

  17. Microplastics in Sewage Sludge: Effects of Treatment. (United States)

    Mahon, A M; O'Connell, B; Healy, M G; O'Connor, I; Officer, R; Nash, R; Morrison, L


    Waste water treatment plants (WWTPs) are receptors for the cumulative loading of microplastics (MPs) derived from industry, landfill, domestic wastewater and stormwater. The partitioning of MPs through the settlement processes of wastewater treatment results in the majority becoming entrained in the sewage sludge. This study characterized MPs in sludge samples from seven WWTPs in Ireland which use anaerobic digestion (AD), thermal drying (TD), or lime stabilization (LS) treatment processes. Abundances ranged from 4196 to 15 385 particles kg-1 (dry weight). Results of a general linear mixed model (GLMM) showed significantly higher abundances of MPs in smaller size classes in the LS samples, suggesting that the treatment process of LS shears MP particles. In contrast, lower abundances of MPs found in the AD samples suggests that this process may reduce MP abundances. Surface morphologies examined using scanning electron microscopy (SEM) showed characteristics of melting and blistering of TD MPs and shredding and flaking of LS MPs. This study highlights the potential for sewage sludge treatment processes to affect the risk of MP pollution prior to land spreading and may have implications for legislation governing the application of biosolids to agricultural land.

  18. On the rheological characteristics of sewage sludge

    Directory of Open Access Journals (Sweden)

    Tomáš Vítěz


    Full Text Available The work is focused on characterization of rheological behavior of sewage sludges sampled at different stages of waste water treatment. The main attention was focused on dynamic viscosity dependence on temperature, and shear rate. The sludge samples were examined under temperature ranging from 1 °C to 25 °C and under shear rate ranging from 0.34 s−1 to 68 s−1. Rotary digital viscometer (concentric cylinders geometry was used to perform the reological measurements. The solids content of the sludge samples ranged from 0.43 % to 21.45 % (A and C samples, respectively and ash free dry mass from 56.21 % to 67.80 % (A and B samples, respectively. The tested materials were found to be of non–Newtoninan nature and temperature dependent. Measured data were successfully cha­ra­cte­ri­zed by several mathematical models (Arrhenius, Bingham Plastic, Casson Law, Exponential, Gaussian, and IPC Paste in MATLAB® software with satisfying correlations between experimental and computed results. The best match (R2 = 0.999 was received with use of Gaussian model, in both cases, shear rate and temperature dependence. The results are quite useful e.g. for the purpose of technological equipment design.

  19. Enhanced compositing of radiation disinfected sewage sludge (United States)

    Kawakami, W.; Hashimoto, S.

    Studies on isothermal composting of radiation disinfected sewage sludge and liquid chromatography of water extracts of the products were carried out. The optimum temperature and pH were around 50 °C and 7-8, respectively. The repeated use of products as seeds increased the rate of CO 2 evolution. The rate reached a maximum within 10 hours and decreased rapidly, and the CO 2 evolution ceased after about 3 days. The conversion of organic carbon to carbon dioxide attained to about 40% for the repeated use of products as seeds at the optimum conditions. As long as seeds in available were used, no remarkable difference was found in the composting of unirradiated and irradiated sludges. The composting process using radiation, however, can be carried out at the optimum conditions and is expected to shorten the composting period, because it is not necessary to keep fermentation temperature higher to reduce pathogen in sludge. Liquid chromatographic studies of the products showed that low molecular components decreased and higher molecular ones increased with fermentation. An index expressing the degree of reduction of easily decomposable organics was presented. The index also showed that the optimum temperature for fermentation was 50 °C, and that the easily decomposable organics disappeared above 30% of the conversion of organic carbon.

  20. Extracellular Polymers in Granular Sludge from Different Upflow Anaerobic Sludge Blanket (UASB) Reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær


    lysis. ECP contents of 41 to 92 mg · g−1 volatile suspended solids of granules were found depending on the type of granular sludge examined. The content of polysaccharides, protein and lipids in the extracted ECP was quantified. Furthermore, the different methyl esters of the lipids were determined...... of an upflow anaerobic sludge blanket reactor from a sugar-containing waste-water to a synthetic waste-water containing acetate, propionate and butyrate resulted in a decrease in both the protein and polysaccharide content and an increase in the lipid content of the extracellular material. Furthermore...

  1. Treatment of slaughterhouse wastewater in an upflow anaerobic sludge blanket reactor: Sludge characteristics


    Mohammad Mehdi Amin; Nasim Rafiei; Ensiyeh Taheri


    Aims: Present study was done by using upflow anaerobic sludge blanket (UASB) reactor to investigate the effect of influent chemical oxygen demand (COD) and organic load rate on the formation of anaerobic granules in wastewater treatment. Martials and Methods: Upflow anaerobic sludge blanket reactor with working volume 30 L was studied using actual slaughterhouse wastewater at a hydraulic retention time of 1.24 d and at temperatures in the range of 35°C ± 0.5°C for 320 days. The inoculum wa...

  2. Investigation of Excess Sludge Generated from Activated Sludge Treatment Plant of Concentrated Latex Factories: An Investigative Case Study in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Wanrudee Wanseng


    Full Text Available Activated sludge technology has been employed for wastewater treatment in the concentrated latex factories in the south of Thailand. This paper highlights the survey results of the excess sludge generated from activated sludge treatment plants of the concentrated latex factories, including sludge generation rate, sludge characteristics, as well as sludge management and its problems. The total number of 11 factories was investigated. The findings showed that 20% of the investigated factories using activated sludge did not know how much the excess sludge generation rate was. With an in-depth investigation, the excess sludge generation rate was determined as for 28 kg/ton concentrated latex product or 10 kg/ton of field latex used in the concentrated latex factories. The excess sludge had a low C/N ratio with an average value of 4.7 and contained N, P, and K with the average of percentage values of 8.0, 2.0, and 1.0% dry basis, respectively. However, the excess sludge consisted of Zn with an average of 3.01% dry basis. 60% of the investigated factories using an activated sludge system had issues concerning the management of excess sludge. Moreover, various aspects of the excess sludge management were discussed and lessons were learned on the current excess sludge management of the concentrated latex industry in the south of Thailand.

  3. Fertilization value of municipal sewage sludge for Eucalyptus camaldulensis plants

    Directory of Open Access Journals (Sweden)

    Soudani Leila


    Full Text Available The wastewater treatment produces a large amount of sludge. The different uses of eliminations sludge such as landfills or incineration have consequences negative for the environment, the agricultural use has increased worldwide, especially in crops and few or no studies have been conducted with forest plantations in Algeria. The objective of this study is to assess fertilizing characteristics of the sludge from the wastewater treatment plant of Tiaret (Algeria. One-year-old saplings of Eucalyptus camaldulensis were transplanted into pots with sludge/soil mixtures where sludge content was 20%, 40% and 60%. Biometric measurements (height, base diameter, diameter at mid-height and the number of leaves were performed during six months after planting. Results demonstrated the positive effect of sludge application. A significant difference in height increment and number of leaves was found between the control and sludge-treated plants. Biometric values for all sludge mixtures were higher than those for control plants (100% soil. The mixture, which contained 60% sludge, gives the best result, except for a diameter of stem. Plants grown on sludge/soil mixture had average height 49.4 ± 24.1 cm and average number of leaves 68.8 ± 6.2 while average height for plants grown on soil was 34.3 ± 12.8 cm and average number of leaves was 40 ± 3.8. Sludge application provides soil amendment and additional nutrient supply for planted trees.

  4. [Effect of different sludge retention time (SRT) on municipal sewage sludge bioleaching continuous plug flow reaction system]. (United States)

    Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng; Wang, Dian-Zhan


    A plug-flow bio-reactor of 700 L working volume for sludge bioleaching was used in this study. The reactor was divided into six sections along the direction of the sludge movement. Fourteen days of continuous operation of sludge bioleaching with different sludge retention time (SRT) under the condition of 1.2 m3 x h(-1) aeration amount and 4 g x L(-1) of microbial nutritional substance was conducted. During sludge bioleaching, the dynamic changes of pH, DO, dewaterability (specific resistance to filtration, SRF) of sewage sludge in different sections were investigated in the present study. The results showed that sludge pH were maintained at 5.00, 3.00, 2.90, 2.70, 2.60 and 2.40 from section 1 to section 6 and the SRF of sludge was drastically decreased from initial 0.64 x 10(13) m x kg(-1) to the final 0.33 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 72 with SRT 2.5d. In addition, the sludge pH were maintained at 5.10, 4.10, 3.20, 2.90, 2.70 and 2.60, the DO value were 0.43, 1.47, 3.29, 4.76, 5.75 and 5.88 mg x L(-1) from section 1 to section 6, and the SRF of sludge was drastically decreased from initial 0.56 x 10(13) to the final 0.20 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 120 with SRT 2 d. The pH value was increased to 3.00 at section 6 at hour 48 h with SRT 1.25 d. The bioleaching system imbalanced in this operation conditions because of the utilization efficiency of microbial nutritional substance by Acidibacillus spp. was decreased. The longer sludge retention time, the easier bioleaching system reached stable. 2 d could be used as the optimum sludge retention time in engineering application. The bioleached sludge was collected and dewatered by plate-and-frame filter press to the moisture content of dewatered sludge cake under 60%. This study would provide the necessary data to the engineering application on municipal sewage sludge bioleaching.

  5. Enhancing faecal sludge management in peri-urban areas of Lusaka through faecal sludge valorisation: challenges and opportunities (United States)

    Tembo, J. M.; Nyirenda, E.; Nyambe, I.


    Lusaka, the capital city of Zambia, has two million inhabitants with 70% residing in peri-urban areas. Ninety (90) % of this population employ pit latrines for excretion generating approximately 22,680 tons of faecal sludge per annum. This sludge is inadequately managed hence of the generated amount, over 60% remains within the residential environment thereby compromising both the environment and public health. To foster a solution to this problem, a study was commissioned to assess faecal sludge valorisation potential and how it would impact on Faecal Sludge Management. The study evaluated policy, institutional and regulatory frameworks, sanitation practices including latrine construction and usage aspects and also characterised the faecal sludge for selected parameters relevant to valorisation. Four peri-urban areas were adopted as study sites. Policy issues together with existing institutional and regulatory frameworks were assessed through literature review. Sanitation practices were evaluated through physical observations, focus group discussions, interviews and questionnaire administration. Faecal sludge characterisation was through sampling and analysis. It was observed that there are policy gaps in fostering faecal sludge valorisation. Sanitation practices and latrines construction also do not favour valorisation. The quality of the raw sludge has potential for valorisation though again, some parameters like solid waste content require drastic changes in sanitation practices in order not to compromise the reuse potential of the sludge. It was concluded that if faecal sludge management is to be enhanced through valorisation, there is need to have policies promoting pit latrine faecal sludge reuse and strengthened regulatory and institutional frameworks in this respect.

  6. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor. (United States)

    Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y


    Conventional activated sludge wastewater treatment plants currently produce a large quantity of excess sludge. To reduce this sludge production and to improve sludge characteristics in view of their subsequent elimination, an ultrasonic cell disintegration process was studied. In a lab-scale continuous flow pilot plant, part of the return sludge was sonicated by low-frequency and high-powered ultrasound and then recycled to the aeration tank. Two parallel lines were used: one as a control and the other as an assay with ultrasonic treatment. The reactors were continuously fed with synthetic domestic wastewater with a COD (chemical oxygen demand) of approximately 0.5 g l(-) corresponding to a daily load of 0.35-0.50 kg COD kg(-1) TS d(-1). Removal efficiencies (carbon, particles), excess sludge production and sludge characteristics (particle size distribution, mineralization, respiration rate, biological component) were measured every day during the 56-day experiment. This study showed that whilst organic removal efficiency did not deteriorate, excess sludge production was decreased by about 25-30% by an ultrasonic treatment. Several hypotheses are advanced: (i) the treatment made a part of the organic matter soluble as a consequence of the floc disintegration, and optimised the conversion of the carbonaceous pollutants into carbon dioxide and (ii) the treatment modified the physical characteristics of sludge by a mechanical effect: floc size was reduced, increasing the exchange surface and sludge activity. The originality of this study is that experiments were conducted in a continuous-flow activated sludge reactor rather than in a batch reactor.

  7. Plant available nitrogen from anaerobically digested sludge and septic tank sludge applied to crops grown in the tropics. (United States)

    Sripanomtanakorn, S; Polprasert, C


    Agricultural land is an attractive alternative for the disposal of biosolids since it utilises the recyclable nutrients in the production of crops. In Thailand and other tropical regions, limited field-study information exists on the effect of biosolids management strategies on crop N utilisation and plant available N (PAN) of biosolids. A field study was conducted to quantify the PAN of the applied biosolids, and to evaluate the N uptake rates of some tropical crops. Sunflower (Helianthus annuus) and tomato (Lycopersicon esculentum) were chosen in this study. Two types of biosolids used were: anaerobically digested sludge and septic tank sludge. The soil is acid sulfate and is classified as Sulfic Tropaquepts with heavy clay in texture. The anaerobically digested sludge applied rates were: 0, 156 and 312 kg N ha(-1) for the sunflower plots, and 0, 586, and 1172 kg N ha(-1) for the tomato plots. The septic tank sludge applied rates were: 0, 95 and 190 kg N ha(-1) for the sunflower plots, and 0, 354 and 708 kg N ha(-1) for the tomato plots, respectively. The results indicated the feasibility of applying biosolids to grow tropical crops. The applications of the anaerobically digested sludge and the septic tank sludge resulted in the yields of sunflower seeds and tomato fruits and the plant N uptakes comparable or better than that applied with only the chemical fertiliser. The estimated PAN of the anaerobically digested sludge was about 27-42% of the sludge organic N during the growing season. For the septic tank sludge, the PAN was about 15-58% of the sludge organic N. It is interesting to observe that an increase of the rate of septic tank sludge incorporated into this heavy clay soil under the cropping system resulted in the decrease of N mineralisation rate. This situation could cause the reduction of yield and N uptake of crops.

  8. The Treatment of Sludge from the Rubber Processing Industry with ...

    African Journals Online (AJOL)

    ... readily available, cheap and easy to handle, more biodegradable, therefore more environmentally friendly. The use of the coagulant for the treatment of sludge and indeed where coagulation and flocculation is desirous can be so recommended. Keywords: Biodegradable, Chitosan, Exoskeleton, Pollution, Sludge,.

  9. Enhanced remediation of an oily sludge with saline water

    African Journals Online (AJOL)


    content (Ayotamuno et al., 2007), its disposal without adequate treatment leads to environmental, particularly soil, pollution. Apart from recent socio-economic problems like ... bioremediation of a heavily polluted oily sludge by bacteria, it is ... The oily sludge used for this study was obtained from the Ocean. Terminal at the ...

  10. Bioleaching of dewatered metal plating sludge by Acidithiobacillus ...

    African Journals Online (AJOL)

    The objective of the present study was to evaluate the application of bioleaching technique to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge not containing sulphide or sulphate compounds. The effects of pH, pulp density of the sludge and agitation time were investigated in both shake ...

  11. Electrokinetic copper and iron migration in anaerobic granular sludge

    NARCIS (Netherlands)

    Virkutyte, J.; Sillanpää, M.J.; Lens, P.N.L.


    The application of low-level direct electric current (0.15 mA cm¿2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially

  12. Sludge reduction by lumbriculus variegatus in Ahvas wastewater treatment plant

    NARCIS (Netherlands)

    Basim, Y.; Farzadkia, M.; Jaafarzadeh, N.; Hendrickx, T.L.G.


    Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. Application of

  13. Bioconversion of paper sludge with low cellulosic content to ethanol ...

    African Journals Online (AJOL)

    The purpose of the present work was to evaluate the possibility of converting paper sludge into ethanol using xylose-fermenting yeast SHY07-1 in separate hydrolysis and fermentation. In the enzymatic hydrolysis step, sludge on 2% (w/v, expressed in terms of total carbohydrate mass) substrate consistency was incubated ...

  14. Disinfection of sewage sludge cake by gamma-irradiation (United States)

    Watanabe, Hiroshi; Takehisa, Masaaki

    Disinfection of municipal sewage sludge cake by gamma-irradiation was reviewed. Total bacterial count in the sludge cake did not vary markedly throughout all four seasons in Japan, and it was in the range of 1.6 × 10 8/g to 4.1 × 10 9/g. Coliform count in aerobically activated sludge was form 1.8 × 10 7/g to 4.8 × 10 8/g, while in anaerobically digested sludge it was less than 8.3 × 10 7/g. The dose to reduce the coliforms to undetectable levels ranged from 0.3 to 0.5 Mrad, depending on the season. In addition, it was observed that no coliforms reappeared in 0.5 Mrad irradiated sludge cake during storage at room temperature (6 - 16°C) and at 30°C. The adequate disinfection dose is therefore considered to be 0.5 Mrad. Pseudomonas cepacia was a predominant bacterium in non-irradiated sludge cake. In a range of 0.5 to 0.7 Mrad, the residual flora consisted of Bacillus species, and radioresistant Deinococcus proteolyticus, Deinococcus radiodurans and Pseudomonas radiora were isolated from sludge cake irradiated at dose levels of more than 1 Mrad. Bacterial regrowth and the growth of Escherichia coli K-12 seeded in irradiated sludge cake are discussed.

  15. Effect of ultrasonic specific energy on waste activated sludge ...

    African Journals Online (AJOL)

    The effect of ultrasonic specific energy on waste activated sludge (WAS) solubilization and enzyme activity was investigated in this study. Experimental results showed that the increase of ultrasonic specific energy in the range of 0 - 90000 kJ/kg dried sludge (DS) benefited WAS particle size reduction and the solubilization ...

  16. Effects of high salinity wastewater on methanogenic sludge bed systems

    NARCIS (Netherlands)

    Ismail, S.; Gonzalez-Contreras, P.A.; Jeison, D.A.; Lier, van J.B.


    The attainable loading potentials of anaerobic sludge bed systems are strongly dependent on the growth of granular biomass with a particular wastewater. Experiments were conducted to determine the effects of high salinity wastewater on the biological and physical properties of methanogenic sludge.

  17. Response of Palm Oil Sludge on Sexual Reproductive Biology and ...

    African Journals Online (AJOL)


    Key-words: Palm oil sludge, Flowering, Root development, Okra, Cowpea, Maize ... effect of crude oil on maize performance and soil chemical properties. .... farmers are advised to only cultivate on lands not heavily contaminated with palm oil ... the fertilizer value of palm oil mill sludge: bio-augmentation in nitrification, Water.

  18. Microwave enhanced digestion of aerobic SBR sludge | Kennedy ...

    African Journals Online (AJOL)

    Biochemical methane potential (BMP) tests at 35oC used to investigate effects of MW temperature, number of MW cycles and partial SBR sludge pretreatment showed that partial MW ... Generally improved biogas production via MW pretreatment was not accompanied by any potential improvement in sludge dewaterability.

  19. Occurrence and survival of pathogens at different sludge depths in ...

    African Journals Online (AJOL)

    Physico-chemical parameters of the faecal sludge were also measured. .... Urea agar slant. (slope) was inoculated and incubated at 37°C for 1–4 h following. APHA (1999). The urease-negative samples were inoculated on. TSI slant and on Day 5 incubated at 37°C for 24 h, ... Physio-chemical properties of pit latrine sludge.

  20. The final destination of the sludges; Destination finale des boues

    Energy Technology Data Exchange (ETDEWEB)

    Rat, D. [Ministere de l' Agriculture et de la Peche, 75 - Paris (France). Direction de l' espace rural et de la foret; Guitton Bernet, I. [HSD Ernst and Young Tour Ersnt andYoung, 92 - Paris-La Defense (France); Jacquinot, B. [Bertin Technologies, 78 - Montigny le Bretonneux (France); Ribeyron, J. [CETIM, 93 - Saint-Ouen (France); Maillot, M. [AM ECO Industries, 30 - Salindres (France); Noel, A. [SYPREA, 75 - Paris (France); Seutin, H. [Vinci Environnement, Rueil Malmaison (France); Buson, Ch. [GES, 35 - Noyal sur Vilaine (France); Solains Ezquerra, R.; Myrope, A. [Lurgi (Germany); Chabrier, J.P. [Sechage Thermique des Boues, 78 - le Pecq (France); Oudenne, D. [Nesa Productlne de Umicore Engineering, Louvain-la-Neuve (Belgium); Cauvin, A. [IKOS Environnement, 76 - Blangy sur Bresle (France); Wacquez, M.L. [TERIS, 78 - Plaisir (France)


    This conference deals with the following topics: the impacts and the stakes around the regulation context and the future of the sludges management; the project management; the processing choice and the valorization; the possible certifications for the sludges; the agricultural valorization; the interests of the thermal valorization; the other possibilities of valorization. (A.L.B.)

  1. Municipal sludge as source of nitrogen and phosphorus in perennial ...

    African Journals Online (AJOL)

    Land application of sludge has been shown to improve soil properties and aid crop growth, but the possibility of constituent nutrients such as nitrogen and phosphorus reaching environmentally toxic levels has caused governing authorities ... The treatments consisted of 0, 4, 8 and 16 Mg∙ha-1 anaerobically digested sludge.

  2. Sulfamethoxazole degradation in anaerobic sulfate-reducing bacteria sludge system. (United States)

    Jia, Yanyan; Khanal, Samir Kumar; Zhang, Huiqun; Chen, Guang-Hao; Lu, Hui


    Sulfamethoxazole (SMX) is one of the most commonly used antibiotics. SMX degradation in sulfate-reducing bacteria (SRB) sludge systems has not been reported so far. This research investigated the SMX degradation using SRB sludge in a sulfate-reducing up-flow sludge bed reactor. Moreover, the mechanisms and kinetics of SMX removal were also investigated using SRB sludge via a series of batch experiments. The results showed that SMX removal was characterized by a rapid sorption onto SRB sludge, and desorption from SRB sludge to aqueous phase until achieving equilibrium, and then followed by slow biodegradation. Biodegradation was the dominant route for SMX removal. The sorption process conformed well to a pseudo-second-order kinetic model, meaning that the sorption occurred primarily via a chemical sorption process. The removal of SMX followed the pseudo-zero-order kinetic model with a specific removal rate of 13.2 ± 0.1 μg/L/d at initial SMX concentration 100 μg/L in batch tests. Based on the analysis of metabolites, most of the SMX biotransformation products' structures altered in the isoxazole ring, which were significantly different from that produced by aerobic and anaerobic sludge systems. Thus, SRB sludge system could play an important role in SMX biodegradation, especially in Sulfate-reduction Autotrophic denitrification and Nitrification Integrated (SANI) process for sewage treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Selected heavy metals speciation in chemically stabilised sewage sludge (United States)

    Wiśniowska, Ewa; Włodarczyk-Makuła, Marła


    Selected heavy metals (Pb, Ni, Cd) were analysed in soil, digested sewage sludge as well as in the sludge stabilised with CaO or Fenton's reagent. The dose of Fenton's reagent was as follows: Fe2+ = 1g.L-1, Fe2+/H2O2=1:100; stabilisation lasted for 2 h. Dose of CaO was equal to 1 g CaO.g d.m.-1 Total concentration of all metals in the digested sewage sludge was higher than in the soil. Chemical stabilisation of sludge with Fenton's reagent increased total metal content in the sludge as a result of total solids removal. Opposite effect was stated when the sludge was mixed with CaO. Also chemical fractions of heavy metals were identified (exchangeable, carbonate bound, iron oxides bound, organic and residual). The results indicate that stabilisation of the sludge with Fenton's reagent increased mobility of heavy metals compared to the digested sludge. Amendment of CaO increased percent share of examined metals in residual fraction, thus immobilised them and decreased their bioavailability.

  4. Aquatic worm reactor for improved sludge processing and resource recovery

    NARCIS (Netherlands)

    Hendrickx, T.L.G.


    Municipal waste water treatment is mainly achieved by biological processes. These processes produce huge volumes of waste sludge (up 1.5 million m3/year in the Netherlands). Further processing of the waste sludge involves transportation, thickening and incineration. A decrease in the amount of waste

  5. Electroosmotically enhanced sludge dewatering-pilot-plant study

    CSIR Research Space (South Africa)

    Smollen, M


    Full Text Available in electroosmotic dewatering which presents a novel approach in South Africa. The separation of the sludge liquid phase is governed by the intensity of binding forces. There are different physical forms of water in sludge and these different forms play an important...

  6. Use of dewatered sludge as microbial inoculum of a subsurface ...

    African Journals Online (AJOL)

    Brown earth–based subsurface wastewater infiltration systems (SWISs) inoculated with/without dewatered sludge were constructed and operated under the same conditions to boost the application of SWIS in brown soil areas. Start-up period of SWIS with dewatered sludge was 28 days, 12 days shorter than that of SWIS ...

  7. Co-composting of sewage sludge and Echinochloa pyramidalis (Lam.)

    African Journals Online (AJOL)

    Yaoundé-Cameroon) in order to assess the effect of three sewage sludge: Macrophyte ratios on the co-composting process and compost quality. The ratios were T1: 25 kg of plant material (Echinochloa pyramidalis) and 75 kg sludge; T2: 50 kg ...

  8. Modeling of Evaporation Losses in Sewage Sludge Drying Bed ...

    African Journals Online (AJOL)

    Modeling of Evaporation Losses in Sewage Sludge Drying Bed. JI Obianyo, JC Agunwamba. Abstract. A model for evaporation losses in sewage sludge drying bed was derived from first principles. This model was developed based on the reasoning that the rate at which evaporation is taking place is directly proportional to ...

  9. Performance of paper mill sludges as landfill capping material

    Energy Technology Data Exchange (ETDEWEB)

    Moo-Young, H.K. Jr. [Lehigh Univ., Bethlehem, PA (United States); Zimmie, T.F. [Rensselaer Polytechnic Institute, Troy, NY (United States)


    The high cost of waste containment has sparked interest in low cost and effective strategies of containing wastes. Paper mill sludges have been effectively used as the impermeable barrier in landfill covers. Since paper mill sludges are viewed as a waste material, the sludge is given to the landfill owner at little or no cost. Thus, when a clay soil is not locally available to use as the impermeable barrier in a cover system, paper sludge barriers can save $20,000 to $50,000 per acre in construction costs. This study looks at the utilization and performance of blended and primary paper sludge as landfill capping material. To determine the effectiveness of paper sludge as an impermeable barrier layer, test pads were constructed to simulate a typical landfill cover with paper sludge and clay as the impermeable barrier and were monitored for infiltration rates for five years. Long-term hydraulic conductivity values estimated from the leachate generation rates of the test pads indicate that paper sludge provides an acceptable hydraulic barrier.

  10. Methylene blue removal by carbonized textile sludge-based adsorbent. (United States)

    Rahman, Ari; Kishimoto, Naoyuki; Urabe, Takeo; Ikeda, Kazuki


    Colored effluent and a large amount of sludge are major pollutant sources derived from textile industry activity. In this research, the idea for converting textile sludge into a potential adsorbent was conducted through a carbonization process in order to solve the colored effluent problem. Textile sludge was carbonized at a temperature ranging from 400 to 800 °C in the absence of oxygen. Maximum adsorption capacity of carbonized sludge for methylene blue removal reached 60.30 mg/g when the sludge was carbonized at 600 °C with specific surface area of 138.9 m 2 /g and no significant alteration was observed until 800 °C. Experimental research by using a real wastewater also showed that there was almost no disruption during adsorption of methylene blue into surface of carbonized sludge. While reactivation process revealed that the regeneration of carbonized sludge was applicable by secondary heating at the same carbonization temperature. Furthermore, the application of this research demonstrated that the carbonized textile sludge was a good adsorbent for methylene blue removal and had a capability to be reactivated.

  11. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants

    NARCIS (Netherlands)

    Temmink, B.G.; Klapwijk, A.


    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg/l and at sludge retention times of 10 and 27

  12. Rhizofiltration of heavy metals from the tannery sludge by the ...

    African Journals Online (AJOL)

    The anchored hydrophyte, Hydrocotyle umbellata L., was employed for the removal of toxic metals from tannery sludge concentrations (w/v) from a tanneries wastewater treatment plant. Different concentrations of wet tannery sludge were prepared and plants of H. umbellata showed a good tolerance for all the prepared ...

  13. efficiency of wastewater treatment by a mixture of sludge

    African Journals Online (AJOL)

    H. Khaldi

    Received: 27 April 2017 / Accepted: 15 July 2017 / Published online: 01 September 2017. ABSTRACT. A combined system using the microalgae from South Africa and the sewage sludge from. Algeria has been tested, in order to study the efficiency of wastewater treatment by mixtures of microalgae / activated sludge, five ...

  14. Variation in VIP latrine sludge contents | Bakare | Water SA

    African Journals Online (AJOL)

    This study investigated variations in the characteristics of the sludge content from different ventilated improved pit (VIP) latrines and variation in these characteristics at specific depths within each pit. Faecal sludge from 16 VIP latrines within the eThekwini Municipality was collected and laboratory characterisation including ...

  15. Dewatering of floated oily sludge by treatment with rhamnolipid. (United States)

    Long, Xuwei; Zhang, Guoliang; Han, Li; Meng, Qin


    Oily sludge dewatering is practically needed prior to sludge treatments. However, the conventional use of physical treatments with or without chemical conditionings presented poor feasibility in industrial applications due to either poor cost-efficiency or lacking environmental friendliness. In this paper, biosurfactant rhamnolipid was for the first time applied for dewatering of oily sludge. Rhamnolipid treatments under the concentration of 300-1000 mg/L, pH of 5-7 and temperature of 10-60 °C could directly separate 50-80% of water from the stable oily sludge. And both mono-rhamnolipid and di-rhamnolipid were identified to be of equivalent dewatering ability, which is closely related to their equivalent performance in breaking the emulsified oil droplets. Demulsification was found to be involved in settling water from oily sludge. Furthermore, the effectiveness of rhamnolipid was further demonstrated at pilot scale (1000 L) treatment of oily sludge. After pilot treatment, the settled water with residual oil of 10 mg/L and soluble COD of about 800 mg/L could be directly effluxed into the biotreatment system while the concentrated oil sludge with a reduced volume by 60-80% can be pumped into coking tower, achieving completely harmless treatment. It seems that rhamnolipid as dewatering agent was of great prospects in the industrial dewatering of oily sludge. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Sustainable sludge management : what are the challenges for the future?

    NARCIS (Netherlands)

    Rulkens, W.H.


    Sewage sludge is a serious problem due to the high treatment costs and the risks to environment and human health. Future sludge treatment will be progressively focused on an improved efficiency and environmental sustainability of the process. In this context a survey is given of the most relevant

  17. The hydraulic transportation of thickened sludges | Slatter | Water SA

    African Journals Online (AJOL)

    An industrially relevant sludge pipe flow study is presented, demonstrating and quantifying the relationship between sludge rheology and flow regime. It is argued that laminar flow will result in settlable solids accumulating on the pipe invert, leading to pipe blockage. Although some practical remedies have been proposed, ...

  18. Caustic Leaching of Hanford Tank S-110 Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Carson, Katharine J.; Darnell, Lori P.; Greenwood, Lawrence R.; Hoopes, Francis V.; Sell, Richard L.; Sinkov, Sergey I.; Soderquist, Chuck Z.; Urie, Michael W.; Wagner, John J.


    This report describes the Hanford Tank S-110 sludge caustic leaching test conducted in FY 2001 at the Pacific Northwest National Laboratory. The data presented here can be used to develop the baseline and alternative flowsheets for pretreating Hanford tank sludge. The U.S. Department of Energy funded the work through the Efficient Separations and Processing Crosscutting Program (ESP; EM﷓50).

  19. Unified Modeling of Filtration and Expression of Biological Sludge

    DEFF Research Database (Denmark)

    Sørensen, Peter Borgen

    Dewatering is a costly operation in both industry, e.g . when dewatering drilling mud, harbor sludge or biomass, and at municipal wastewater treatment plants when dewatering biological sludges. In practice, design and operation of dewatering equipment are mostly based on empirical knowledge...

  20. Submersible microbial fuel cell for electricity production from sewage sludge

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit


    A submersible microbial fuel cell (SMFC) was utilized to treatment of sewage sludge and simultaneous generate electricity. Stable power generation (145±5 mW/m2) was produced continuously from raw sewage sludge for 5.5 days. The corresponding total chemical oxygen demand (TCOD) removal efficiency...


    Directory of Open Access Journals (Sweden)

    Ewelina Nowicka


    Full Text Available The formation of sludge is an inevitable consequence of wastewater treatment processes. Their disposal and utilization requires knowledge on technology and engineering. The application of pretreatment processes/conditioning allows to obtain better mechanical properties of sludge. In the last decade a lot of research from around the world focused on new methods of conditioning of sludge can be noticed, i.e. The processes of disintegration, of which the destruction of the mechanical, chemical and biological. Despite different activities of each method (introduced energy, thermal phenomena, chemical reactions, mechanical, their common goal is the destruction of activated sludge floc structure and micro-organisms, which result in changes of properties in sediment and supernatant liquid. The influence of the disintegration of the microwave and freezing/thawing dry ice on selected properties of gravitational surplus activated sludge were presented. Characteristic parameters determined sludge sedimentation processes, i.e. the rate of descent and compaction density index sediment and sludge volume index and changes in the supernatant liquid. The study showed the efficacy of selected methods of sludge disintegration with regard to improving the properties of gravity and becoming a contribution to the determination of the effective methods of deposits’ preconditioning.

  2. Municipal sludge-industrial sludge composite desulfurization adsorbents: synergy enhancing the catalytic properties. (United States)

    Bandosz, Teresa J; Block, Karin


    Mixtures of sewage sludge, waste oil sludge, and metal oil sludge were prepared and carbonized at 950 degrees C in an inert atmosphere. Dynamic adsorption of H2S was measured on the materials obtained, and the breakthrough capacity was calculated. The initial and exhausted adsorbents after the breakthrough tests were characterized using sorption of nitrogen, thermal analysis, and XRF, XRD, and surface pH measurements. Mixing sludges leads to very high capacity adsorbents on which hydrogen sulfide is oxidized to elemental sulfur. Although the micropore volume of the adsorbents obtained is not high, their high volume of mesopores contributes significantly to reactive adsorption and provides space to store the oxidation products. The H2S breakthrough capacity on the new materials reaches 10 wt %. These adsorbents work until all active pores are filled and the catalytic centers are exhausted. The reason for such high capacity is in the formation of catalytically active mineral like phases during pyrolysis in the presence of nitrogen and carbon. This highly dispersed phase provides basicity and catalytic centers for hydrogen sulfide dissociation and its oxidation to sulfur.

  3. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    NARCIS (Netherlands)

    Leitao, R.; Santaellla, S.T.; Haandel, van A.C.; Zeeman, G.; Lettinga, G.


    The effects of hydraulic retention time (HRT) and influent COD concentration (CODInf) on Specific Methanogenic Activity (SMA) and the biodegradability of an anaerobic sludge need to be elucidated because of the discordant results available in literature. This information is important for the

  4. Co-digestion of Primary sludge with cow dung and brewery sludge ...

    African Journals Online (AJOL)



    Feb 18, 2015 ... unit which was continuously aerated, a settling unit and a sludge return device. The CSTR unit had a volume of 4 L .... 1), the effluent concentrations were less variable ranging between 0.030 to 0.250 mg mL-1. ..... microorganisms and reduce pathogen transmission, it is recommended that the effluent be ...

  5. Achieving partial denitrification with sludge fermentation liquid as carbon source: the effect of seeding sludge. (United States)

    Cao, Shenbin; Wang, Shuying; Peng, Yongzhen; Wu, Chengcheng; Du, Rui; Gong, Lingxiao; Ma, Bin


    The partial denitrification (nitrate to nitrite) has been a promising way for nitrate wastewater treatment combined with ANAMMOX system subsequently. This work investigated the effect of seeding sludge on partial denitrification by using sludge fermentation liquid as carbon source, with the sludge taken from: anoxic/oxic reactor (SA), anaerobic-anoxic-oxic reactor (SA-A-O) and alternately anaerobic sludge fermentation coupling anoxic denitrification reactor (SA-A). The results showed that transient accumulation of nitrite was observed in SA and SA-A-O. However, at the initial nitrate concentration of 30 mg/L, a high nitrite of 20.91 ± 0.52 mg/L was accumulated under complete nitrate reduction in the SA-A system, which indicated that partial denitrification could be realized. Furthermore, as much as 80% nitrate-to-nitrite transformation ratio (NTR) was achieved in a 108-day operation with inoculating SA-A, which illustrated the stability of partial denitrification under long-term operation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Co-digestion of Primary sludge with cow dung and brewery sludge ...

    African Journals Online (AJOL)



    Feb 18, 2015 ... hydraulic retention time of under 30 min selects for rapid incorporation of ... Average operating parameters of the high rate activated sludge (HRAS), the alternating charcoal filter 1(ACF1) with a retention time of 2.5 h and the ...... wetlands treating domestic wastewater: A case study of the Juja sewage ...

  7. Wastewater sludge - the challenges. What are the potentials of utilising the resources in sludge?

    Energy Technology Data Exchange (ETDEWEB)

    Kroiss, Helmut


    The actual best practice of urban water management has developed during the last 200 years and consists of: safe and reliable drinking water supply, sewerage to prevent hygienic problems and flooding in the settlements, mechanical -biological waste water treatment for receiving water protection. The hygienic and environmental goals of the urban water system have to be attained with a minimum of costs. Most of the drinking water supplied is used for the transport of pollution originating from human metabolism, washing and cleaning. Waste water contains all the substances which enter human metabolism as food, beverages, pharmaceuticals, a great variety of household chemicals and the substances discharged from trade and industry to the sewer system. Rain water is already contaminated by air pollution when it reaches the soil or other surfaces. Whatever material the rainwater gets into contact can be found in the waste water. As a consequence the composition of the waste water is a mirror of our civilisation and of human and urban metabolism. Waste water treatment results in two products which are closely related in their chemical composition: (1) treated waste water to be discharged to the receiving water, (2) wastewater sludge to be treated and disposed or (re)used without creating new (environmental) problems. All the compounds entering the waste water which are not completely degraded can be found in both products. The transfer coefficients between water and sludge differ widely and depend on physical and chemical equilibriums. The potentially hazardous compounds in the effluent and in the sludge belong to these compounds. Source control therefore is necessary for water protection and at the same time for low concentrations of potentially hazardous compounds in the sludge. It is also clear that improved biological treatment efficiency (longer sludge age) also results in lower loads of organic pollutants in the sludge, while physical-chemical treatment steps result

  8. High Level Waste System Impacts from Acid Dissolution of Sludge

    Energy Technology Data Exchange (ETDEWEB)



    This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.

  9. Analysis of sludge from Hanford K East Basin canisters

    Energy Technology Data Exchange (ETDEWEB)

    Makenas, B.J. [ed.] [comp.] [DE and S Hanford, Inc., Richland, WA (United States); Welsh, T.L. [B and W Protec, Inc. (United States); Baker, R.B. [DE and S Hanford, Inc., Richland, WA (United States); Hoppe, E.W.; Schmidt, A.J.; Abrefah, J.; Tingey, J.M.; Bredt, P.R.; Golcar, G.R. [Pacific Northwest National Lab., Richland, WA (United States)


    Sludge samples from the canisters in the Hanford K East Basin fuel storage pool have been retrieved and analyzed. Both chemical and physical properties have been determined. The results are to be used to determine the disposition of the bulk of the sludge and to assess the impact of residual sludge on dry storage of the associated intact metallic uranium fuel elements. This report is a summary and review of the data provided by various laboratories. Although raw chemistry data were originally reported on various bases (compositions for as-settled, centrifuged, or dry sludge) this report places all of the data on a common comparable basis. Data were evaluated for internal consistency and consistency with respect to the governing sample analysis plan. Conclusions applicable to sludge disposition and spent fuel storage are drawn where possible.

  10. Solidification of low-volume power plant sludges. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bell, N.E.; Halverson, M.A.; Mercer, B.M.


    A literature review was conducted to obtain information on the status of hazardous waste solidification technology and application of this technology to low-volume power plant waste sludges. Because of scarcity of sludge composition data, anticipated major components were identified primarily by chemical reactions that are known to occur during treatment of specific wastewaters. Chemical and physical properties of these sludges were critically analyzed for compatibility with several types of commercially available solidification processes. The study pointed out the need for additional information on the nature of these sludges, especially leaching characteristics and the presence of substances that will interfere with solidification processes. Laboratory studies were recommended for evaluation of solidification process which have the greatest potential for converting hazardous low-volume sludges to non-hazardous waste forms.

  11. Pretreatment of sewage sludge by using the radiation technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. G.; Yu, D. H.; Lee, B. J.; Lee, M. J. [KAERI, Taejon (Korea, Republic of)


    A study on enhancement of sludge dewaterability and disinfection of the microorganisms in sewage sludge by using radiation technology was accomplished. Moisture content in sludge was reduced by using irradiation and adding the starfish as a dewatering aid. Moisture content was reduced by 20%(w/w) after irradiation and adding the dewatering aid while decreased by {approx}7%(w/w) after only irradiation. The amount of coagulant to form sludge flocs was dramatically increased in accordance with the irradiation dose because of the degradation of sludge particles but it was reduced when adding the dewatering aid. The colony forming unit of bacteria and E.coli were reduced over 99% after irradiation at the dose of >1kGy and SCOD, S-protein and S-carbohydrate were largely increased after irradiation.

  12. Use of DAIME for characterisation of activated sludge flocs

    Directory of Open Access Journals (Sweden)

    Gnida Anna


    Full Text Available Monitoring of activated sludge flocs may provide important information for effective operation and control of wastewater treatment. The research objective is to demonstrate methodology for activated sludge image processing aimed to describe morphological characteristics of activated sludge flocs. The proposed software- -based method was presented and verified by analysis of several activated sludge samples. The results show high efficiency of image segmentation and floc recognition of more than 94% floc components. The analysis of a series of 50 pictures gives rapid and reliable results and can be performed in an automatic or semiautomatic mode. Given inherent heterogeneity of activated sludge flocs, multiple and repeated sample images capture (processing of 50 pictures at a time, repeated at least 4 times is recommended.

  13. Stabilization of Mercury in High pH Tank Sludges

    Energy Technology Data Exchange (ETDEWEB)

    Spence, R.; Barton, J.


    DOE complex contains many tank sludges contaminated with mercury. The high pH of these tank sludges typically fails to stabilize the mercury, resulting in these radioactive wastes also being characteristically hazardous or mixed waste. The traditional treatment for soluble inorganic mercury species is precipitation as insoluble mercuric sulfide. Sulfide treatment and a commercial mercury-stabilizing product were tested on surrogate sludges at various alkaline pH values. Neither the sulfide nor the commercial product stabilized the mercury sufficiently at the high pH of the tank sludges to pass the Toxicity Characteristic Leach Procedure (TCLP) treatment standards of the Resource Conservation and Recovery Act (RCRA). The commercial product also failed to stabilize the mercury in samples of the actual tank sludges.


    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Edwards, T.


    The Defense Waste Processing Facility (DWPF) is preparing to initiate processing Sludge Batch 7b (SB7b). In support of the upcoming processing, the Savannah River National Laboratory (SRNL) provided a recommendation to utilize Frits 418 with a 6% Na{sub 2}O addition (26 wt% Na{sub 2}O in sludge) and 702 with a 4% Na{sub 2}O addition (24 wt% Na{sub 2}O in sludge) to process SB7b. This recommendation was based on assessments of the compositional projections for SB7b available at the time from the Savannah River Remediation (SRR). To support qualification of SB7b, SRNL executed a variability study to assess the applicability of the current durability models for SB7b. The durability models were assessed over the expected composition range of SB7b, including potential caustic additions, combined with Frits 702 and 418 over a 32-40% waste loading (WL) range. Thirty four glasses were selected based on Frits 418 and 702 coupled with the sludge projections with an additional 4-6% Na{sub 2}O to reflect the potential caustic addition. Six of these glasses, based on average nominal sludge compositions including the appropriate caustic addition, were developed for both Frit 418 and Frit 702 at 32, 36 and 40% WL to provide coverage in the center of the anticipated SB7b glass region. All glasses were fabricated and characterized using chemical composition analysis, X-ray diffraction (XRD) and the Product Consistency Test (PCT). To comply with the DWPF Glass Product Control Program, a total of thirty four glasses were fabricated to assess the applicability of the current DWPF PCCS durability models. Based on the measured PCT response, all of the glasses were acceptable with respect to the Environmental Assessment (EA) benchmark glass regardless of thermal history. The NL[B] values of the SB7b variability study glasses were less than 1.99 g/L as compared to 16.695 g/L for EA. A small number of the D-optimally selected 'outer layer' extreme vertices (EV) glasses were not

  15. Effect of sludge retention on UF membrane fouling: The significance of sludge crystallization and EPS increase. (United States)

    Yu, Wenzheng; Graham, Nigel; Yang, Yunjia; Zhou, Zhiqi; Campos, Luiza C


    This paper concerns a previously unreported mechanism of membrane ultrafiltration (UF) fouling when a UF process with coagulation pre-treatment is used in drinking water treatment. The significance of settled coagulant solids (sludge) with different age within the membrane tank on UF fouling has been investigated at laboratory-scale, using model micro-polluted surface water. The process of floc crystallization and increasing bacterial EPS with solids (sludge) retention time may be detrimental to UF operation by causing an increased rate of membrane fouling. In this study the performance of two alum pre-treated hollow-fibre UF units, operated in parallel but with different settled sludge retention times (1 and 7 days), was compared. The results showed that over 34 days of operation the extent of reversible and irreversible fouling was much greater for the 7-day solids retention time. This was attributed to the greater extent of bacterial activity and the presence of Al-nanoparticles, arising from sludge crystallization, at the longer retention time. In particular, greater quantities of organic matter, particularly EPS (proteins and polysaccharides), were found in the UF cake layer and pores for the 7-day retention time. The addition of chlorine later in the membrane run substantially reduced the rate of membrane fouling for both sludge retention times, and this corresponded to reduced quantities of organic substances, including EPS, in the cake layer and pores of both membranes. The results suggest that bacterial activity (and EPS production) is more important than the production of Al-nanoparticles from solids crystallization in causing membrane fouling. However, it is likely that both phenomena are interactive and possibly synergistic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Vitrification as an alternative to landfilling of tannery sewage sludge. (United States)

    Celary, Piotr; Sobik-Szołtysek, Jolanta


    Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling. The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification. The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives. One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to

  17. Polyphosphate Kinase from Activated Sludge Performing Enhanced Biological Phosphorus Removal† (United States)

    McMahon, Katherine D.; Dojka, Michael A.; Pace, Norman R.; Jenkins, David; Keasling, Jay D.


    A novel polyphosphate kinase (PPK) was retrieved from an uncultivated organism in activated sludge carrying out enhanced biological phosphorus removal (EBPR). Acetate-fed laboratory-scale sequencing batch reactors were used to maintain sludge with a high phosphorus content (approximately 11% of the biomass). PCR-based clone libraries of small subunit rRNA genes and fluorescent in situ hybridization (FISH) were used to verify that the sludge was enriched in Rhodocyclus-like β-Proteobacteria known to be associated with sludges carrying out EBPR. These organisms comprised approximately 80% of total bacteria in the sludge, as assessed by FISH. Degenerate PCR primers were designed to retrieve fragments of putative ppk genes from a pure culture of Rhodocyclus tenuis and from organisms in the sludge. Four novel ppk homologs were found in the sludge, and two of these (types I and II) shared a high degree of amino acid similarity with R. tenuis PPK (86 and 87% similarity, respectively). Dot blot analysis of total RNA extracted from sludge demonstrated that the Type I ppk mRNA was present, indicating that this gene is expressed during EBPR. Inverse PCR was used to obtain the full Type I sequence from sludge DNA, and a full-length PPK was cloned, overexpressed, and purified to near homogeneity. The purified PPK has a specific activity comparable to that of other PPKs, has a requirement for Mg2+, and does not appear to operate in reverse. PPK activity was found mainly in the particulate fraction of lysed sludge microorganisms. PMID:12324346

  18. Oxygen transfer dynamics and activated sludge floc structure under different sludge retention times at low dissolved oxygen concentrations. (United States)

    Fan, Haitao; Liu, Xiuhong; Wang, Hao; Han, Yunping; Qi, Lu; Wang, Hongchen


    In activated sludge systems, the aeration process consumes the most energy. The energy cost can be dramatically reduced by decreasing the operating dissolved oxygen (DO) concentration. However, low DO may lead to incomplete nitrification and poor settling performance of activated sludge flocs (ASFs). This study investigates oxygen transfer dynamics and settling performances of activated sludge under different sludge retention times (SRTs) and DO conditions using microelectrodes and microscopic techniques. Our experimental results showed that with longer SRTs, treatment capacity and settling performances of activated sludge improved due to smaller floc size and less extracellular polymeric substances (EPS). Long-term low DO conditions produced larger flocs and more EPS per unit sludge, which produced a more extensive anoxic area and led to low oxygen diffusion performance in flocs. Long SRTs mitigated the adverse effects of low DO. According to the microelectrode analysis and fractal dimension determination, smaller floc size and less EPS in the long SRT system led to high oxygen diffusion property and more compact floc structure that caused a drop in the sludge volume index (SVI). In summary, our results suggested that long SRTs of activated sludge can improve the operating performance under low DO conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A Study of the Utilization of Palm Fruit Sludge for Food Preparations ...

    African Journals Online (AJOL)

    In the study, palm fruit sludge was recovered and used in human food preparation. The sludge was obtained from palm fruit waste liquid through filtration and dewatering. The wet sludge was dried at 50°C, milled into powder and sieved to obtain the dry powder. Proximate analysis of the dry sludge showed that it contained ...

  20. Zinc uptake by vegetables: Effects of soil type and sewage sludge ...

    African Journals Online (AJOL)

    Studies were carried out to investigate how sludge applied to 3 soil types to improve the yield of carrots (Daucus carota) and spinach (Spinacea oleracea) would affect the amount of Zn taken up by these vegetables. A 3 year old (type 1 sludge) and a 3 month old (type 2 sludge) sludge were applied to a vertisol, an arenosol, ...

  1. The effect of ageing on the fertilizer value of sludge from Botswana ...

    African Journals Online (AJOL)

    This study was designed to characterize sludge of three different ages (36 months old, 3 months old and fresh sludge referred to as Type 1, Type 2 and Type 3 sludge respectively) in an endeavor to appreciate their suitability for use as manure for arable agriculture. Sludge properties including volatile solid and nutrient ...

  2. Elucidating the microbial community associated with the protein preference of sludge-degrading worms

    NARCIS (Netherlands)

    de Valk, S.L.; Feng, C.; Khadem, A.F.; van Lier, J.B.; de Kreuk, M.K.


    Sludge predation by aquatic worms results in an increased sludge reduction rate, which is mainly due to the specific removal of a protein fraction from the sludge. As microorganisms play an essential role in sludge hydrolysis a better understanding of the microbial community involved in the worm

  3. Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge

    NARCIS (Netherlands)

    Virkutyte, J.; Hullebusch, van E.D.; Sillanpaa, M.; Lens, P.N.L.


    The effect of electrokinetic treatment (0.15 mA cm(-2)) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg(-1) wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention

  4. The effect of ageing on the fertilizer value of sludge from Botswana ...

    African Journals Online (AJOL)


    ABSTRACT: This study was designed to characterize sludge of three different ages (36 months old, 3 months old and fresh sludge referred to as Type 1, Type 2 and Type 3 sludge respectively) in an endeavor to appreciate their suitability for use as manure for arable agriculture. Sludge properties including volatile solid and ...

  5. Removal of heavy metals from sewage sludge by extraction with organic acids

    NARCIS (Netherlands)

    Veeken, A.H.M.; Hamelers, H.V.M.


    Waste water treatment in activated sludge plants results in the production of large amounts of surplus sludge. After composting the sludge can be reused as fertiliser and soil conditioner in agriculture. Compared to landfilling and incineration, utilisation of sludge-compost is a more sustainable

  6. Degradation of Triclosan in aerated sludge

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina

    %. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we......Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore...

  7. Who is actively denitrifying in activated sludge?

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Nielsen, Jeppe Lund

    -scale wastewater treatment plant the transcripts (mRNA) of the nirS, nirK and nosZ denitrification genes expressed under acetate or amino acid consumption were amplified, sequenced and identified. This revealed that the majority of the denitrifiers belonged to Alpha- and Betaproteobacteria, while only few...... with Bacteroidetes. Furthermore, potential denitrifying genera of Alpha- and Betaproteobacteria were quantified in the activated sludge with 16S rRNA gene probes for fluorescence in situ hybridization (FISH). This revealed that Aquaspirillum-related bacteria were dominant followed by bacteria related to Azoarcus...... by microautoradiography combined with FISH....

  8. Analysis and modelling of predation on biofilm activated sludge process: Influence on microbial distribution, sludge production and nutrient dosage. (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R


    The influence of predation on the biofilm activated sludge (BAS) process is studied using a unified model that incorporates hydrolysis and predation phenomena into the two stages of the BAS system: moving bed biofilm reactor pre-treatment (bacterial-predator stage) and activated sludge (predator stage). The unified model adequately describes the experimental results obtained in a cellulose and viscose full-scale wastewater plant and has been used to evaluate the role and contribution of predator microorganisms towards removal of COD, nutrient requirements, sludge production and microbial distribution. The results indicate that predation is the main factor responsible for the reduction of both nutrient requirements and sludge production. Furthermore, increasing the sludge retention time (SRT) does not influence the total biomass content in the AS reactor of a BAS process in two different industrial wastewater treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. CFD analysis of sludge accumulation and hydraulic performance of a waste stabilization pond. (United States)

    Alvarado, Andres; Sanchez, Esteban; Durazno, Galo; Vesvikar, Mehul; Nopens, Ingmar


    Sludge management in waste stabilization ponds (WSPs) is essential for safeguarding the system performance. Sludge accumulation patterns in WSPs are strongly influenced by the pond hydrodynamics. CFD modeling was applied to study the relation between velocity profiles and sludge deposition during 10 years of operation of the Ucubamba WSP in Cuenca (Ecuador). One tracer experiment was performed and three sludge accumulation scenarios based on bathymetric surveys were simulated. A residence time distribution (RTD) analysis illustrated the decrease of residence times due to sludge deposition. Sludge accumulation rates were calculated. The influence of flow pattern on the sludge deposition was studied, enabling better planning of future pond operation and desludging.


    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J; Cj Bannochie, C; Damon Click, D; Dan Lambert, D; Michael Stone, M; Bradley Pickenheim, B; Amanda Billings, A; Ned Bibler, N


    Sludge Batch 5 (SB5) is predominantly a combination of H-modified (HM) sludge from Tank 11 that underwent aluminum dissolution in late 2007 to reduce the total mass of sludge solids and aluminum being fed to the Defense Waste Processing Facility (DWPF) and Purex sludge transferred from Tank 7. Following aluminum dissolution, the addition of Tank 7 sludge and excess Pu to Tank 51, Liquid Waste Operations (LWO) provided the Savannah River National Laboratory (SRNL) a 3-L sample of Tank 51 sludge for SB5 qualification. SB5 qualification included washing the sample per LWO plans/projections (including the addition of a Pu/Be stream from H Canyon), DWPF Chemical Process Cell (CPC) simulations, waste glass fabrication (vitrification), and waste glass chemical durability evaluation. This report documents: (1) The washing (addition of water to dilute the sludge supernatant) and concentration (decanting of supernatant) of the Tank 51 qualification sample to adjust sodium content and weight percent insoluble solids to Tank Farm projections. (2) The performance of a DWPF CPC simulation using the washed Tank 51 sample. This includes a Sludge Receipt and Adjustment Tank (SRAT) cycle, where acid is added to the sludge to destroy nitrite and remove mercury, and a Slurry Mix Evaporator (SME) cycle, where glass frit is added to the sludge in preparation for vitrification. The SME cycle also included replication of five canister decontamination additions and concentrations. Processing parameters for the CPC processing were based on work with a non radioactive simulant. (3) Vitrification of a portion of the SME product and Product Consistency Test (PCT) evaluation of the resulting glass. (4) Rheology measurements of the initial slurry samples and samples after each phase of CPC processing. This work is controlled by a Task Technical and Quality Assurance Plan (TTQAP) , and analyses are guided by an Analytical Study Plan. This work is Technical Baseline Research and Development (R

  11. [Adsorption of a dye by sludges and the roles of extracellular polymeric substances]. (United States)

    Kong, Wang-sheng; Liu, Yan


    This paper investigated the adsorption of a dye, acid turquoise blue A, by four kinds of sludges including activated sludge, anaerobic sludge, dried activated sludge, and dried anaerobic sludge, respectively. The roles of extracellular polymeric substances (EPS) including the soluble EPS (SEPS) and bound EPS (BEPS) for the biosorption of activated sludge and anaerobic sludge were further studied. Results show that the relation between four kinds of sludge adsorption amount and remained concentration of the dye fitted well both Freundlich model (R2: 0.921-0.995) and Langmuir model (R2: 0.958-0.993), but not quite fitted BET model (R2: 0.07-0.863). The adsorption capability of dried anaerobic sludge ranked the highest, and dried activated sludge was the lowest. According to Langmuir isotherm, the maximum adsorption amount of dried anaerobic, anaerobic, activated, and dried activated sludge was 104 mg/g, 86 mg/g, 65 mg/g, 20 mg/g, respectively. The amount of the dye found in EPS for both activated sludge and anaerobic sludge were over 50%, illustrating that EPS adsorption was predominant in adsorption of the dye by sludge. The amount of adsorbed dye by BEPS was greater than that by SEPS for anaerobic sludge, but for activated sludge the result was quite opposite. The amount of adsorbed dye by unit mass SEPS was much higher than the corresponding values of BEPS for both sludges. The average amount of adsorbed dye by unit mass SEPS was 52 times of the corresponding value of BEPS for activated sludge, and 10 times for anaerobic sludge. The relation between adsorption amount of dye by BEPS from anaerobic sludge and remained concentration of the dye in mixed liquor was best fitted to Langmuir model (R2: 0.9986).

  12. Decomposition and nitrogen transformations in digested sewage sludge applied to mine tailings


    Wennman, Pär


    Applying sewage sludge to mine tailings to encourage growth of vegetation in order to prevent environmental problems such as erosion and leaching of metals began around 1970. Use of sewage sludge for mine land reclamation is today an acceptable area of application and is in many cases preferable to spreading sludge as an organic fertilizer on agricultural land, since many sludges contain metals and pathogens. The sludge has been shown to be favourable compared to other additives that do not c...


    Directory of Open Access Journals (Sweden)

    Syamsudin Syamsudin


    Full Text Available Kraft pulp mill sludge cake composed of rejected wood fibers and activated sludge microorganisms. With a heating value about 14 MJ/kg (dried basis, this type of biomass had a potential as an alternative energy source. Unfortunately, it had an ash content of 27.6% and a moisture content of 80%. For reducing moisture content with minimum energy consumption, a combination of mechanical dewatering and thermal drying was studied previously. Meanwhile, experiments on isothermal pyrolysis had been carried out for further improvement on ultimate and proximate analysis of solid fuel. Final mass of char obtained from pyrolysis at 500oC was not significantly different from that of 700oC, so pyrolysis was considered to be optimum at 500oC. A char obtained from pyrolysis at temperature of 500oC had a pore surface area of 77.049 m2/g (highest among other temperatures. Kinetic of isothermal pyrolysis was well represented with a first order modified volumetric model with a frequency factor of 0.782 1/s and an activation of 34.050 kJ/mol.

  14. Effect of microwave pre-treatment of thickened waste activated sludge on biogas production from co-digestion of organic fraction of municipal solid waste, thickened waste activated sludge and municipal sludge. (United States)

    Ara, E; Sartaj, M; Kennedy, K


    Anaerobic co-digestion of organic fraction of municipal solid waste, with thickened waste activated sludge and primary sludge has the potential to enhance biodegradation of solid waste, increase longevity of existing landfills and lead to more sustainable development by improving waste to energy production. This study reports on mesophilic batch and continuous studies using different concentrations and combinations (ratios) of organic fraction of municipal solid waste, thickened waste activated sludge (microwave pre-treated and untreated) and primary sludge to assess the potential for improved biodegradability and specific biogas production. Improvements in specific biogas production for batch assays, with concomitant improvements in total chemical oxygen demand and volatile solid removal, were obtained with organic fraction of municipal solid waste:thickened waste activated sludge:primary sludge mixtures at a ratio of 50:25:25 (with and without thickened waste activated sludge microwave pre-treatment). This combination was used for continuous digester studies. At 15 d hydraulic retention times, the co-digestion of organic fraction of municipal solid waste:organic fraction of municipal solid waste:primary sludge and organic fraction of municipal solid waste:thickened waste activated sludge microwave:primary sludge resulted in a 1.38- and 1.46-fold increase in biogas production and concomitant waste stabilisation when compared with thickened waste activated sludge:primary sludge (50:50) and thickened waste activated sludge microwave:primary sludge (50:50) digestion at the same hydraulic retention times and volumetric volatile solid loading rate, respectively. The digestion of organic fraction of municipal solid waste with primary sludge and thickened waste activated sludge provides beneficial effects that could be implemented at municipal wastewater treatment plants that are operating at loading rates of less than design capacity. © The Author(s) 2014.

  15. Behavior of radioactive materials and safety stock of contaminated sludge. (United States)

    Tsushima, Ikuo


    The radioactive fallout from the Fukushima Dai-ichi nuclear power plant disaster in 2011 has flowed into and accumulated in many wastewater treatment plants (WWTPs) via sewer systems; this has had a negative impact on WWTPs in eastern Japan. The behavior of radioactive materials was analyzed at four WWTPs in the Tohoku and Kanto regions to elucidate the mechanism by which radioactive materials are concentrated during the sludge treatment process from July 2011 to March 2013. Furthermore, numerical simulations were conducted to study the safe handling of contaminated sewage sludge stocked temporally in WWTPs. Finally, a dissolution test was conducted by using contaminated incinerated ash and melted slag derived from sewage sludge to better understand the disposal of contaminated sewage sludge in landfills. Measurements indicate that a large amount of radioactive material accumulates in aeration tanks and is becoming trapped in the concentrated sludge during the sludge condensation process. The numerical simulation indicates that a worker's exposure around contaminated sludge is less than 1 µSv/h when maintaining an isolation distance of more than 10 m, or when shielding with more than 20-cm-thick concrete. The radioactivity level of the eluate was undetectable in 9 out of 12 samples; in the remaining three samples, the dissolution rates were 0.5-2.7%.

  16. Assessment of aluminum bioavailability in alum sludge for agricultural utilization. (United States)

    Kluczka, Joanna; Zołotajkin, Maria; Ciba, Jerzy; Staroń, Magdalena


    Inorganic aluminum ions, [Al(H2O)6]3+, [Al(OH)(H2O)5]2+, and [Al(OH)2(H2O)4]+, are toxic to a number of crops. The aim of this study was to estimate the danger of soil contamination of bioavailable aluminum and heavy metals forms because of alum sludge which was a by-product of water, and wastewater treatment technology using aluminum coagulant is introduced into the soil. Aluminum and selected heavy metal fractionation was carried out in the post-coagulation sludge collected at a water treatment plant (where aluminum was used as a coagulant), fermented sewage sludge at a municipal wastewater treatment plant (which did not apply aluminum coagulant), and soil from water treatment plant as well as the mixtures of sludge and soil. It has been found that post-coagulation sludge used as natural fertilizer is a secondary source of bioavailable aluminum, especially when aluminum coagulants are used during water and wastewater treatment. The evaluation of applicability of the sludge to very weak acidic and acidic agricultural soils was carried out. The authors shall debate the question whether, in this case, the Regulation of EU and Polish Government on sewage sludge should also take the bioavailable aluminum into account and add to the list of the elements whose allowable contents are limited.

  17. Co-digestion of pig slaughterhouse waste with sewage sludge. (United States)

    Borowski, Sebastian; Kubacki, Przemysław


    Slaughterhouse wastes (SHW) are potentially very attractive substrates for biogas production. However, mono-digestion of these wastes creates great technological problems associated with the inhibitory effects of ammonia and fatty acids on methanogens as well as with the foaming in the digesters. In the following study, the co-digestion of slaughterhouse wastes with sewage sludge (SS) was undertaken. Batch and semi-continuous experiments were performed at 35°C with municipal sewage sludge and pig SHW composed of meat tissue, intestines, bristles and post-flotation sludge. In batch assays, meat tissue and intestinal wastes gave the highest methane productions of 976 and 826 dm(3)/kg VS, respectively, whereas the methane yield from the sludge was only 370 dm(3)/kg VS. The co-digestion of sewage sludge with 50% SHW (weight basis) provided the methane yield exceeding 600 dm(3)/kg VS, which was more than twice as high as the methane production from sewage sludge alone. However, when the loading rate exceeded 4 kg VS/m(3) d, a slight inhibition of methanogenesis was observed, without affecting the digester stability. The experiments showed that the co-digestion of sewage sludge with large amount of slaughterhouse wastes is feasible, and the enhanced methane production does not affect the digester stability. Copyright © 2015 Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)



    Full Text Available Fresh activated sludge in many wastewater treatment plants may be considered unhealthy due to the large amount of organic and organism content. Due to the lack of research on municipal sludge, there is an apparent scarcity of actual data. Thus, this work will focus on the characterization of fresh activated sludge. The effect of dosage of different polyelectrolytes and coagulants has been investigated at pH level in a comparative fashion that is commonly associated with fresh activated sludge. The results indicated that the cationic polyelectrolytes had significant effluence on the sludge properties, degree of flocculation and water quality. With respect to the optical analyses, it was observed that the floc sizes and densities were increased with rise concentrations of both types of cationic polyelectrolytes. It was found that the cationic CPAM-80 was the most effective chemical among other six used chemicals especially for solutions with pH near neutrality despite of the variations in feed properties of the fresh activated sludge. This polyelectrolyte gave lower turbidity, lower sludge volume index, faster zone settling rate and large floc density.

  19. Review on innovative techniques in oil sludge bioremediation (United States)

    Mahdi, Abdullah M. El; Aziz, Hamidi Abdul; Eqab, Eqab Sanoosi


    Petroleum hydrocarbon waste is produced in worldwide refineries in significant amount. In Libya, approximately 10,000 tons of oil sludge is generated in oil refineries (hydrocarbon waste mixtures) annually. Insufficient treatment of those wastes can threaten the human health and safety as well as our environment. One of the major challenges faced by petroleum refineries is the safe disposal of oil sludge generated during the cleaning and refining process stages of crude storage facilities. This paper reviews the hydrocarbon sludge characteristics and conventional methods for remediation of oil hydrocarbon from sludge. This study intensively focuses on earlier literature to describe the recently selected innovation technology in oily hydrocarbon sludge bioremediation process. Conventional characterization parameters or measurable factors can be gathered in chemical, physical, and biological parameters: (1) Chemical parameters are consequently necessary in the case of utilization of topsoil environment when they become relevant to the presence of nutrients and toxic compounds; (2) Physical parameters provide general data on sludge process and hand ability; (3) Biological parameters provide data on microbial activity and organic matter presence, which will be used to evaluate the safety of the facilities. The objective of this research is to promote the bioremediating oil sludge feasibility from Marsa El Hariga Terminal and Refinery (Tobruk).

  20. Sludge reduction using aquatic worms under different aeration regimes. (United States)

    Cai, Lu; Gao, Ding; Wang, Kan; Liu, Hong-Tao; Wan, Xiao-Ming


    Adding aquatic worms to a wastewater treatment system can reduce sludge production through predation. The aeration level is crucial for success. To evaluate aeration impacts on sludge reduction and determine an optimal aeration regime, this study investigated the processes of in-situ sludge reduction, using aquatic worms exposed to different aeration levels. The experiment also compared treatment results between a conventional reactor and an aquatic worm reactor (WR). Results indicated that the recommended concentration of dissolved oxygen (DO) was 2.5 mg L-1. The removal rate of chemical oxygen demand remained steady at 80% when the DO concentration was higher than 2.5 mg L-1, while the removal rate of ammonia nitrogen continued to moderately increase. Increasing the DO concentration to 5 mg L-1 did not improve sludge reduction, and consumed more power. With a DO concentration of 2.5 mg L-1 and a power of 0.19 kWh t-1 water, the absolute sludge reduction and relative sludge reduction rates in the WR were 60.0% and 45.7%, respectively, and the daily aquatic worm growth rate was 0.150 d-1 during the 17-d test. Therefore, at the recommended aeration regime, aquatic worms reduced the sludge without increasing the power consumption or deteriorating the effluent.

  1. CFD simulation of anaerobic digester with variable sewage sludge rheology. (United States)

    Craig, K J; Nieuwoudt, M N; Niemand, L J


    A computational fluid dynamics (CFD) model that evaluates mechanical mixing in a full-scale anaerobic digester was developed to investigate the influence of sewage sludge rheology on the steady-state digester performance. Mechanical mixing is provided through an impeller located in a draft tube. Use is made of the Multiple Reference Frame model to incorporate the rotating impeller. The non-Newtonian sludge is modeled using the Hershel-Bulkley law because of the yield stress present in the fluid. Water is also used as modeling fluid to illustrate the significant non-Newtonian effects of sewage sludge on mixing patterns. The variation of the sewage sludge rheology as a result of the digestion process is considered to determine its influence on both the required impeller torque and digester mixing patterns. It was found that when modeling the fluid with the Hershel-Bulkley law, the high slope of the sewage stress-strain curve at high shear rates causes significant viscous torque on the impeller surface. Although the overall fluid shear stress property is reduced during digestion, this slope is increased with sludge age, causing an increase in impeller torque for digested sludge due to the high strain rates caused by the pumping impeller. Consideration should be given to using the Bingham law to deal with high strain rates. The overall mixing flow patterns of the digested sludge do however improve slightly. Copyright © 2013 Elsevier Ltd. All rights reserved.


    Energy Technology Data Exchange (ETDEWEB)



    In 2010, an innovative, remotely operated retrieval system was deployed to successfully retrieve over 99.7% of the radioactive sludge from ten submerged tanks in Hanford's K-West Basin. As part of K-West Basin cleanup, the accumulated sludge needed to be removed from the 0.5 meter diameter by 5 meter long settler tanks and transferred approximately 45 meters to an underwater container for sampling and waste treatment. The abrasive, dense, non-homogeneous sludge was the product of the washing process of corroded nuclear fuel. It consists of small (less than 600 micron) particles of uranium metal, uranium oxide, and various other constituents, potentially agglomerated or cohesive after 10 years of storage. The Settler Tank Retrieval System (STRS) was developed to access, mobilize and pump out the sludge from each tank using a standardized process of retrieval head insertion, periodic high pressure water spray, retraction, and continuous pumping of the sludge. Blind operations were guided by monitoring flow rate, radiation levels in the sludge stream, and solids concentration. The technology developed and employed in the STRS can potentially be adapted to similar problematic waste tanks or pipes that must be remotely accessed to achieve mobilization and retrieval of the sludge within.

  3. Acetate-triggered granular sludge floatation in methanogenic bioreactors. (United States)

    Wang, Shanquan; Liang, Zhiwei


    Methanogenic granular sludge from anaerobic bioreactors plays a primary role in treatment of various high-strength industrial wastewaters. The common problem of sludge floatation can lead to washout of granules from the reactor and severely affect reactor performance. However, an understanding of the specific key trigger-factors and appropriate control strategies for granular sludge floatation remains elusive. In this study, the concentration of acetate, rather than that of other volatile fatty acids (VFAs, i.e. propionate and butyrate) and granular sludge properties, was identified to be positively, linearly correlated with the amount of floating granules. The number of floating granules on propionate (18 ± 6) or butyrate-containing (34 ± 13) wastewater was comparable with that of non-VFA control wastewater (30.5 ± 7.5), and much lower than that of acetate-containing wastewater (80.5 ± 10.5). A scenario of excessive acetate-triggered granular sludge floatation is proposed based on these results as well as on the microbial community profile and spatial distribution, porous structure of granules, and impacts of operational parameters. Two new strategies, acetate-depletion and co-substrate addition, effectively reduced the number of floating granules by 28.5% and 51.6%, respectively. These results deepen our understanding of granular sludge floatation in methanogenic bioreactors and provide effective strategies to control sludge floatation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Improvement of sludge removal performance for steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, K. [Steam Generator Designing Section, Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Sakai, K.; Ito, H.; Tanahashi, A. [Mechanical Engineering and Water Chemistry Group, Kansai Electric Power Co., Inc., Osaka (Japan); Nakao, F. [Service Technology Development Dept., Nuclear Plant Service Engineering Co., Ltd., Mitsubishi Heavy Industries, Ltd., Kobe (Japan)


    Scale, mainly consisting of magnetite, flows on the secondary side of steam generators (SGs), causing the formation of concentrations of impurities on the tubesheet (TS), increasing the fouling of tube heat transfer, and blocking the broached egg crates (BEC) on the tube support plates (TSP). Accumulation of sludge on the tubesheet forms environment in which impurities are highly concentrated on the tubes. And we have experienced tube degradation, in the past, from the concentration of impurities. In Japan, the first tubesheet sludge lancing, via water jets, was done at the Mihama-2 plant in 1975. And that is why this pile sludge becomes hard depending on time, removal made an effort toward removal with CECIL* (in bundle cleaning system) us very difficulty. However, sludge remained in localized areas and it had possibility of concentration. So that we improve the CECIL for the purpose of removing it, and we improved removal performance of the device. In addition to the improvement of CECIL, we install a sludge collector in order to decrease accumulation of sludge on the tubesheet. This paper introduces these improvements in sludge removal performance. (authors)

  5. Using microbiological leaching method to remove heavy metals from sludge

    Directory of Open Access Journals (Sweden)

    Zhuyu Gu


    Full Text Available Microbial leaching is one of the most effective methods to remove heavy metals from sludge. In the conducted researches, the sludge samples were processed with Thiobacillus ferrooxidans and Thiobacillus thiooxidans obtained via cultivation, extraction and purification processes. Heavy metals such as Pb, Cd, Cu and Ni were leached from sludge by Thiobacillus ferrooxidans and Thiobacillus thiooxidans within different substrate concentration and pH value conditions. It is defined that from the point of view of economy and efficiency the optimal concentration of FeSO4.7H2O and sulfur for bio-leaching process was 0.2 g. The leaching rates of heavy metals such as Pb, Cd, Cu and Ni of the same concentration were 74.72%, 81.54%, 70.46% and 77.35% respectively. However, no significant differences depending on the pH value among the leaching rates were defined, even for the pH value of 1.5. Along with the removal of heavy metals from sludge, the organic matter, N, P, K were also leached to some extent. The losing rate of phosphorus was the highest and reached 38.44%. However, the content of organic matter, N, P, K in the processed sludge were higher in comparison with level I of the National Soil Quality Standards of China. Ecological risk of heavy metals in sludge before and after leaching was assessed by Index of Geo-accumulation (Igeo and comprehensive potential risk (RI. The results of research defined that the content of heavy metals in sludge meets the level of low ecological risk after leaching and their contents is lower in comparison with the National Agricultural Sludge Standard of China. Sludge leached by biological methods is possible to use for treatment for increasing soil fertility.

  6. Low intensity surplus activated sludge pretreatment before anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan


    Full Text Available Sewage sludge (municipal, or industrial treatment is still a problem in so far that it is not satisfactorily resolved in terms of cost and final disposal. Two common forms of sludge disposal are possible; the first being direct disposal on land (including agriculture and the second being incineration (ash production, although neither of these methods are universally applied. Simplifying the issue, direct sludge disposal on land is seldom applied for sanitary and environmental reasons, while incineration is not popular for financial (high costs reasons. Very often medium and large wastewater treatment plants apply anaerobic digestion for sludge hygiene principles, reducing the amount to be disposed and for biogas (energy production. With the progress in sewage biological treatment aiming at nutrient removal, primary sludge has been omitted in the working processes and only surplus activated sludge requires handling. Anaerobic digestion of waste activated sludge (WAS is more difficult due to the presence of microorganisms, the decomposition of which requires a relatively long time for hydrolysis. In order to upgrade the hydrolysis effects, several different pre-treatment processes have already been developed and introduced. The additional pre-treatment processes applied are aimed at residual sludge bulk mass minimization, shortening of the anaerobic digestion process or higher biogas production, and therefore require additional energy. The water-energy-waste Nexus (treads of of the benefits and operational difficulties, including energy costs are discussed in this paper. The intensity of pre-treatment processes to upgrade the microorganism’s hydrolysis has crucial implications. Here a low intensity pre-treatment process, alkalisation and hydrodynamic disintegration - hybrid process - were presented in order to achieve sufficient effects of WAS anaerobic digestion. A sludge digestion efficiency increase expressed as 45% biogas additional

  7. Sewage sludge as a biomass resource for the production of energy: Overview and assessment of the various options

    NARCIS (Netherlands)

    Rulkens, W.H.


    Treatment of municipal wastewater results worldwide in the production of large amounts of sewage sludge. The major part of the dry matter content of this sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary (microbiological) sludge. The sludge also

  8. Pathogens in Sludge: A Case of Sufficient Challenge

    Energy Technology Data Exchange (ETDEWEB)

    Lesilind, R. Aarne


    There is increasing pressure in many countries to strengthen the regulations controlling the land disposal of wastewater sludges. In this paper I argue that although there is little doubt that sludges from wastewater treatment contain pathogenic organisms, not only are there no data to show that such disposal is a public health problem, but I want to suggest that small doses of pathogens in the environment provide a ''sufficient challenge'' that actually enhances public health. There therefore seems little reason, from a public health standpoint, to pass stricter sludge disposal regulations. (author)

  9. Investigation of the bio pile treatment for oily sludge (United States)

    Bai, He; Wang, Xinxin; Chen, Yu; Cao, Xingtao; Ma, Zhengzhao; Guo, Bing; Zhao, Guangyu; Li, Chen


    With the rapid development of petro-chemical industry as well as the stricter requirement of environmental protection, the treatment of oily sludge is around the corner for the petroleum companies. A pilot experiment had been carried out in this study to investigate the changes of n-alkanes, polycyclic aromatic hydrocarbons and total petroleum hydrocarbons in the oily sludge. Results show that the oil content in the sludge decreased to 5023 mg/kg within 90 days, which provide technical support for the engineering application of bio pile treatment

  10. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla, Dept. de Ingenieria Quimica y Ambiental, Sevilla (Spain); Gutierrez, J.C. [Universidad Pablo de Olavide, Dept. de Ciencias Ambientales, Sevilla (Spain); Lebrato, J. [Universidad de Sevilla, Grupo Tratamiento de Aguas Residuales, Sevilla (Spain)


    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (Author)

  11. Thermoradiation treatment of sewage sludge using reactor waste fission products

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M. C.; Hagengruber, R. L.; Zuppero, A. C.


    The hazards to public health associated with the application of municipal sewage sludge to land usage are reviewed to establish the need for disinfection of sludge prior to its distribution as a fertilizer, especially in the production of food and fodder. The use of ionizing radiation in conjunction with mild heating is shown to be an effective disinfection treatment and an economical one when reactor waste fission products are utilized. A program for researching and experimental demonstration of the process on sludges is also outlined.

  12. 241-Z-361 Sludge Characterization Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)



    This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.

  13. The role of Lecane rotifers in activated sludge bulking control. (United States)

    Fiałkowska, Edyta; Pajdak-Stós, Agnieszka


    Experiments were conducted on Lecane inermis feeding on filamentous bacteria and living in activated sludge to determine if the rotifers can control the growth of the bacteria responsible for bulking. The experiments showed that Lecane are capable of significantly reducing the density of Microthrix parvicella filaments. The rotifers not only survived the transfer from the culture to the activated sludge, but they multiplied quickly when foraging on filamentous bacteria. By reducing the number of filaments, the rotifers improved settling properties of the sludge. This is apparently the first report on the possibility of using rotifers to control bulking.

  14. Application of waterworks sludge in wastewater treatment plants

    DEFF Research Database (Denmark)

    Sharma, Anitha Kumari; Thornberg, D.; Andersen, Henrik Rasmus


    The potential for reuse of iron-rich sludge from waterworks as a replacement for commercial iron salts in wastewater treatment was investigated using acidic and anaerobic dissolution. The acidic dissolution of waterworks sludge both in sulphuric acid and acidic products such as flue gas washing...... for removal of phosphate in the wastewater treatment was limited, because the dissolved iron in the digester liquid was limited by siderite (FeCO3) precipitation. It is concluded that both acidic and anaerobic dissolution of iron-rich waterworks sludge can be achieved at the wastewater treatment plant...

  15. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica. Departamento de Ingenieria Quimica y Ambiental; Gutierrez, J.C. [Universidad Pablo de Olavide, Sevilla (Spain). Departamento de Ciencias Ambientales; Lebrato, J. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica


    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (author)

  16. 241-Z-361 Sludge Characterization Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)



    This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.

  17. Shear Strength Measurement Benchmarking Tests for K Basin Sludge Simulants

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Carolyn A.; Daniel, Richard C.; Enderlin, Carl W.; Luna, Maria; Schmidt, Andrew J.


    Equipment development and demonstration testing for sludge retrieval is being conducted by the K Basin Sludge Treatment Project (STP) at the MASF (Maintenance and Storage Facility) using sludge simulants. In testing performed at the Pacific Northwest National Laboratory (under contract with the CH2M Hill Plateau Remediation Company), the performance of the Geovane instrument was successfully benchmarked against the M5 Haake rheometer using a series of simulants with shear strengths (τ) ranging from about 700 to 22,000 Pa (shaft corrected). Operating steps for obtaining consistent shear strength measurements with the Geovane instrument during the benchmark testing were refined and documented.

  18. From municipal/industrial wastewater sludge and FOG to fertilizer: A proposal for economic sustainable sludge management. (United States)

    Bratina, Božidar; Šorgo, Andrej; Kramberger, Janez; Ajdnik, Urban; Zemljič, Lidija Fras; Ekart, Janez; Šafarič, Riko


    After a ban on the depositing of untreated sludge in landfills, the sludge from municipal and industrial water-treatment plants can be regarded as a problem. Waste products of the water treatment process can be a problem or an opportunity - a source for obtaining raw materials. In the European Union, raw sludge and fats, oil and grease (FOG) from municipal and industrial wastewater treatment plants (WWTP) cannot be deposited in any natural or controlled environment. For this reason, it must be processed (stabilized, dried) to be used later as a fertilizer, building material, or alternative fuel source suitable for co-incineration in high temperature furnaces (power plants or concrete plants). The processes of drying sludge, where heat and electricity are used, are energy consuming and economically unattractive. Beside energy efficiency, the main problem of sludge drying is in its variability of quality as a raw material. In addition to this, sludge can be contaminated by a number of organic and inorganic pollutants and organisms. Due to the presence or absence of pollutants, different end products can be economically interesting. For example, if the dried sludge contains coliform bacteria, viruses, helminths eggs or smaller quantities of heavy metals, it cannot be used as a fertilizer but can still be used as a fuel. The objectives of the current article is to present a batch-processing pilot device of sludge or digestate that allows the following: (1) low pressure and low temperature energy effective drying of from 10 to 40% remaining water content, (2) disinfection of pathogen (micro)organisms, (3) heavy metal reduction, (4) production of products of predetermined quality (e.g. containing different quantities of water; it can be used as a fertilizer, or if the percentage of water in the dry sludge is decreased to 10%, then the dried sludge can be used as a fuel with a calorific value similar to coal). An important feature is also the utilization of low

  19. The chemical and mechanical differences between alginate-like exopolysaccharides isolated from aerobic flocculent sludge and aerobic granular sludge. (United States)

    Lin, Y M; Sharma, P K; van Loosdrecht, M C M


    This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two exopolysaccharides were chemically fractionated, and investigated by FT-IR spectroscopy. The isolated polymers were made into a gel by calcium addition and the mechanical properties of these reconstituted gels were measured by a low load compression tester. The viscoelastic behavior of the gels was described by a generalized Maxwell model. The alginate-like exopolysaccharides derived from aerobic granules had significantly higher amount of poly(guluronic acid) blocks but lower amount of poly(guluronic acid-manuronic acid) blocks in the chemical structure, while the alginate-like exopolysaccharides derived from aerobic flocculent sludge had equal amount of poly(guluronic acid) blocks and poly(guluronic acid-manuronic acid) blocks. These differences result in a perfect gel-forming capability of alginate-like exopolysaccharides derived from aerobic granules and bestowed this exopolysaccharides gel a stronger mechanical property as compared to alginate-like exopolysaccharides derived from aerobic flocculent sludge. The different chemical and mechanical properties of these two exopolysaccharides contributed to the distinguished characteristics between aerobic granular sludge and aerobic flocculent sludge. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Operational strategies for an activated sludge process in conjunction with ozone oxidation for zero excess sludge production during winter season. (United States)

    Lee, J W; Cha, H-Y; Park, K Y; Song, K-G; Ahn, K-H


    A pilot-scale activated sludge system coupled with sludge ozonation process was operated for 112 days of a winter season without excess sludge wasting. The concept of this process is that the excess sludge produced is first disintegrated by ozone oxidation and then recirculated to a bioreactor in order to mineralize the particulate and soluble organic compounds. The basis of operation was to determine either the optimal amount of sludge in kg SS ozonated each day (SO) or the optimal ozonation frequency under the variable influent chemical oxygen demand (COD) loading and temperature conditions, since the ozone supply consumes costly energy. The optimal SO was obtained using the theoretically estimated sludge production rate (SP) and experimentally obtained ozonation frequency (n). While the SP was mainly subject to the COD loadings, sludge concentration was affected by the temperature changes in winter season. The optimal n was observed between 2.5 and 2.7 at around 15 degrees C, but it was doubled at 10 degrees C. Mixed liquor suspended solids (MLSS) concentration was leveled off at around 5000 mg/L in bioreactor at 15 degrees C, but the volatile fraction of MLSS was fixed around 0.7 indicating that there was no significant inorganic accumulation. Suspended solids (SS) and soluble COD in effluents kept always a satisfactory level of 10 and 15 mg/L with sufficient biodegradation. It was recommended to apply a dynamic SO under variable influent COD loadings and temperature conditions to the activated sludge system without excess sludge production for saving energy as well as system stabilization.

  1. Communal sewage sludge treatement against the background of the new European Sewage Sludge Treatment Regulations; Kommunale Klaerschlammbehandlung vor dem Hintergrund der neuen Europaeischen Klaerschlammrichtlinien

    Energy Technology Data Exchange (ETDEWEB)



    The following issues were discussed at the Darmstadt conference: The European Sewage Sludge Treatment Regulation, hygienisation of sewage sludge, waste water purification without excess sludge production, stabilisation of sewage sludge, dewatering and disposal by combustion or utilisation as an agricultural fertilizer. [German] Themen des Darmstaedter Seminars Abwassertechnik waren: Europaeische Klaerschlammrichtlinie, Klaerschlammhygienisierung, Abwasserreinigung ohne Anfall von Ueberschussschlamm, Klaerschlammstabilisierung, Entwaesserung und Entsorgung durch Verbrennung oder in der Landwirtschaft. (UKE)

  2. Emissions of CO2 and CH4 from sludge treatment reed beds depend on system management and sludge loading

    DEFF Research Database (Denmark)

    Olsson, Linda; Dam Larsen, Julie; Ye, Siyuan


    Sludge treatment reed beds (STRB) are considered as eco-friendly and sustainable alternatives to conventional sludge treatment methods, although little is known about greenhouse gas emissions from such systems. We measured CO2 and CH4 emissions and substrate characteristics in a STRB......, the SD had no vegetation and a poor dewatering capacity, which resulted in anaerobic conditions favoring CH4 emission. In contrast, the well-managed STRB had more aerobic conditions in the sludge residue resulting in low CH4 emission rates. We conclude that well-designed and well-managed STRBs have a low...

  3. Determination of fluoroquinolone antibacterial agents in sewage sludge and sludge-treated soil using accelerated solvent extraction followed by solid-phase extraction. (United States)

    Golet, Eva M; Strehler, Adrian; Alder, Alfredo C; Giger, Walter


    A method for the quantitative determination of humanuse fluoroquinolone antibacterial agents (FQs) ciprofloxacin and norfloxacin in sewage sludge and sludge-treated soil samples was developed. The accelerated solvent extraction was optimized with regard to solvents and operational parameters, such as temperature, pressure, and extraction time. A 50 mM aqueous phosphoric acid/ acetonitrile mixture (1:1) was found to be optimum in combination with an extraction temperature of 100 degrees C at 100 bar, during 60 and 90 min for sewage sludge and sludge-treated soil samples, respectively. A cleanup step using solid-phase extraction substantially improved the selectivity of the method. Overall recovery rates for FQs ranged from 82 to 94% for sewage sludge and from 75 to 92% for sludge-treated soil, with relative standard deviations between 8 and 11%. Limits of quantification were 0.45 and 0.18 mg/kg of dry matter for sewage sludge and sludge-treated soils, respectively. The presented method was successfully applied to untreated and anaerobically digested sewage sludges and sludge-treated soils. Ciprofloxacin and norfloxacin were determined in sewage sludges from several wastewater treatment plants with concentrations ranging from 1.40 to 2.42 mg/kg of dry matter. Therefore, contrary to what may be expected for human-use pharmaceuticals, FQs may reach the terrestrial environment as indicated by the occurrence of FQs in topsoil samples from experimental fields, to which sewage sludge had been applied.

  4. Short Horizon Control Strategies for an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard


    Three control strategies allowing improved operational flexibility of an alternating type activated sludge process are presented in a unified model based framework. The control handles employed are the addition rate of an external carbon source to denitrification, the cycle length...

  5. Impact of sludge flocs on membrane fouling in membrane bioreactors

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Niessen, Wolfgang; Jørgensen, Mads Koustrup

    of divalent ions such as calcium and iron. Furthermore, it was shown that the ratio between cations and EPS was important for the fouling potential of the sludge. A high ratio between divalent ions and EPS reduced membrane fouling as soluble EPS were adsorbed and bound within the sludge flocs. Strong compact...... flocs reduced membrane fouling, and more compact and strong flocs were formed if the concentration of divalent ions were high. Sludge was fractionated by centrifugation providing supernatant with soluble EPS and colloidal particles but without flocs. Filtration test on untreated sludge and supernatant...... determines floc structure, which was not further determined here. However, presence of strong flocs are usually also supported when the concentration of divalent ions is high, the ionic strength is low and the reactor is well-aerated....

  6. Sludge pipe flow pressure drop prediction using composite power ...

    African Journals Online (AJOL)


    , pressure gradient, sludge rheology. Notation ... This paper describes the application of a tech- nique presented by Garcia et al. ..... composite power law fric- tion factor correlations for laminar and turbulent gas–liquid flow in.

  7. Energy and Resource Recovery from Sludge. State of Science Report

    Energy Technology Data Exchange (ETDEWEB)

    Kalogo, Y.; Monteith, H. [Hydromantis Inc., Hamilton, ON (Canada)


    There is general consensus among sanitary engineering professionals that municipal wastewater and wastewater sludge is not a 'waste', but a potential source of valuable resources. The subject is a major interest to the members of the Global Water Research Coalition (GWRC). The GWRC is therefore preparing a strategic research plan related to energy and resource recovery from wastewater sludge. The initial focus of the strategy will be on sewage sludge as water reuse aspects have been part of earlier studies. The plan will define new research orientations for deeper investigation. The current state of science (SoS) Report was prepared as the preliminary phase of GWRC's future strategic research plan on energy and resource recovery from sludge.

  8. Characterization and distribution of esterase activity in activated sludge

    NARCIS (Netherlands)

    Boczar, BA; Forney, LJ; Begley, WM; Larson, RJ; Federle, TW


    The location and activity of esterase enzymes in activated Sludge from three Municipal wastewater treatment plants were characterized using model Substrate, and denaturing and nondenaturing polyacrylamide gel electrophoresis (PAGE) Of particulate, freeze thaw (primarily periplasmic enzymes and those

  9. Biodegradation of waste PET based copolyesters in thermophilic anaerobic sludge

    Czech Academy of Sciences Publication Activity Database

    Hermanová, S.; Šmejkalová, P.; Merna, J.; Zarevúcka, Marie


    Roč. 111, Jan (2015), s. 176-184 ISSN 0141-3910 Institutional support: RVO:61388963 Keywords : poly(ethylene terephthalate) * copolymers * sludge * biodegradation * hydrolysis * waste Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.120, year: 2015

  10. Cobalt toxicity in anaerobic granular sludge: influence of chemical speciation

    NARCIS (Netherlands)

    Bartacek, J.; Fermoso, F.G.; Baldo-Urrutia, A.M.; Hullebusch, van E.D.; Lens, P.N.L.


    The influence of cobalt speciation on the toxicity of cobalt to methylotrophic methanogenesis in anaerobic granular sludge was investigated. The cobalt speciation was studied with three different media that contained varying concentrations of complexing ligands [carbonates, phosphates and

  11. Extraction of structural extracellular polymeric substances from aerobic granular sludge

    NARCIS (Netherlands)

    Felz, S.; Al-zuhairy, S.H.K.; Aarstad, Olav Andreas; van Loosdrecht, Mark C.M.; Lin, Y.


    To evaluate and develop methodologies for the extraction of gel-forming extracellular polymeric substances (EPS), EPS from aerobic granular sludge (AGS) was extracted using six different methods (centrifugation, sonication, ethylenediaminetetraacetic acid (EDTA), formamide with sodium hydroxide


    This report details the stability assessment of a mercury containing sulfide treatment sludge. Information contained in this report will consist of background data submitted by the geneerator, landfill data supplied by EPA and characterization and leaching studies conducted by UC...

  13. Factors influencing the density of aerobic granular sludge.

    NARCIS (Netherlands)

    Winkler, M.K.; Kleerebezem, R.; Strous, M.; Chandran, K.; Loosdrecht, M.C. van


    In the present study, the factors influencing density of granular sludge particles were evaluated. Granules consist of microbes, precipitates and of extracellular polymeric substance. The volume fractions of the bacterial layers were experimentally estimated by fluorescent in situ hybridisation

  14. Characteristics of biosolids from sludge treatment wetlands for agricultural reuse

    DEFF Research Database (Denmark)

    Uggetti, Enrica; Ferrer, Ivet; Nielsen, Steen


    Sludge treatment wetlands (STW) consist of constructed wetlands systems specifically developed for sludge treatment over the last decades. Sludge dewatering and stabilisation are the main features of this technology, leading to a final product which may be recycled as an organic fertiliser or soil...... 1.5–5.0% TS to 18–26% TS. Organic matter biodegradation leads to VS around 43–46% TS and COD around 500–700 g/kg TS. The values of the DRI24 h (0.5–1.4 mg O2/g TS h) indicate that treated sludge is an almost stabilised final product. Both heavy metals and faecal bacteria indicators meet current...

  15. phytoremediation of sewage sludge in soils contaminated with ...

    African Journals Online (AJOL)


    plant-associated microbes and plants-induced changes in the contaminated environment, transport of contaminants into the plant system is highly dominated by ... plant carbon compounds. (exudates, mucilage, dead cells). Activation, Detoxification,. Mineralization. PHYTOREMEDIATION OF SEWAGE SLUDGE IN SOILS ...

  16. Documentation of a decision framework to support enhanced sludge washing

    Energy Technology Data Exchange (ETDEWEB)

    Brothers, A.J.


    This document describes a proposed decision model that, if developed to its fullest, can provide a wide range of analysis options and insights to pretreatment/sludge washing alternatives. A recent decision has been made to terminate this work

  17. Occurrence and survival of pathogens at different sludge depths in ...

    African Journals Online (AJOL)

    Occurrence and survival of pathogens at different sludge depths in unlined pit latrines in Kampala slums. Sylivia Nabateesa, Ahamada Zziwa, Isa Kabenge, Robert Kambugu, Joshua Wanyama, Allan John Komakech ...

  18. Thermal power sludge – properties, treatment, utilization

    Directory of Open Access Journals (Sweden)

    Martin Sisol


    Full Text Available In this paper a knowledge about properties of thermal power sludge from coal combustion in smelting boilers is presented. The physical and technological properties of slag – granularity, density, specific, volume and pouring weight, hardness and decoupling – together with chemical properties influence its exploitation. The possibility of concentrating the Fe component by the mineral processing technologies (wet low-intenzity magnetic separation is verified. An industrial use of the slag in civil engineering, e.g. road construction, was realised. The slag-fly ashes are directly utilized in the cement production as a substitute of a part of natural raw materials. For the use of slag as the stoneware in the road construction, all the criteria are fulfilled.

  19. Vitrification as an alternative to landfilling of tannery sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Celary, Piotr, E-mail:; Sobik-Szołtysek, Jolanta, E-mail:


    Highlights: • The possibility of vitrification of tannery sewage sludge was investigated. • Glass cullet was substituted with different wastes of mineral character. • Component ratio in the processed mixtures was optimized. • Environmental safety of the acquired vitrificates was verified. • An alternative management approach of usually landfilled waste was presented. - Abstract: Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling. The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification. The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives. One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with

  20. Supercritical water pyrolysis of sewage sludge. (United States)

    Ma, Wenchao; Du, Guiyue; Li, Jian; Fang, Yuanhao; Hou, Li'an; Chen, Guanyi; Ma, Degang


    Municipal sewage sludge (SS) from wastewater treatment plant containing high water content (>85wt.%), lead to the difficulty of co-combustion with MSW or coal due to the high cost of drying. This study explores an alternative method by supercritical water (SCW) pyrolysis of sewage sludge (SS) in a high pressure reaction vessel. The effects of temperature and moisture content of SS on yield and composition of the products (bio-oil, bio char and non-condensable gas) were studied. A temperature of 385°C and moisture content of 85wt.% were found to be the optimum conditions for the maximum bio-oil production of 37.23wt.%, with a higher heating value of 31.08MJ/kg. In the optimum condition, the yields of aliphatic hydrocarbon and phenols were about 29.23wt.% and 12.51wt.%, respectively. The physical and chemical properties of bio-char were analyzed by using XRF and BET. Results of GC analyses of NCG showed that it has the maximum HHV of 13.39MJ/m(3) at 445°C and moisture content of 85wt.%. The reaction path from SS to bio-oil through SCW pyrolysis was given. Moreover, carbon balance was calculated for the optimal condition, and finding out that 64.27wt.% of the carbon content was transferred from SS to bio-oil. Finally, this work demonstrates that the SCW pyrolysis is a promising disposal method for SS. Copyright © 2016. Published by Elsevier Ltd.

  1. Monitoring of biopile composting of oily sludge. (United States)

    Kriipsalu, Mait; Nammari, Diauddin


    This paper describes a bioreactor set-up used to simulate degradation of petroleum hydrocarbons in a static biopile. The large-scale test was performed in a 28 m(3) custom-designed reactor. Oily sludge (40% by weight, having 7% dry matter [DM], and hydrocarbons C(10)-C(40) 160,000 mg kg(-1) DM) was mixed with organic-rich amendments - mature oil-compost (40%) and garden waste compost (20%). Within the reactor, the temperature and soil gases were monitored continuously during 370 days via 24 measurement points. Also, moisture content was continuously recorded and airflow through compost mix occasionally measured. Three-dimensional ordinary kriging spatial models were created to describe the dynamic variations of temperature, air distribution, and hydrocarbon concentration. There were large temperature differences in horizontal and vertical sections during initial months of composting only. Water content of the mixture was uneven by layers, referring on relocation of moisture due to aeration and condensation. The air distribution through the whole reactor varied largely despite of continuous aeration, while the concentration of O(2) was never reduced less than 1-2% on average. The results showed that composting of sludge using force-aerated static biopile technology was justified during the first 3-4 months, after which the masses could be re-mixed and heaped for further maturation in low-tech compost windrows. After 370 days of treatment, the content of hydrocarbons (C( 10)-C(40)) in the compost mixture was reduced by 68.7%.

  2. Cephalosporin-induced biliary sludge in children

    Directory of Open Access Journals (Sweden)

    A.E. Abaturov


    Full Text Available Background. One of the side effects of the third generation cephalosporins is the formation of cephalosporin-induced biliary pseudolithiasis (CIBPL. The purpose of the study was to establish the peculiarities of the formation of biliary sludge during the application of the third generation cephalosporins in the treatment of acute respiratory infections in children. Materials and methods. We examined 46 children aged 2 to 15 years with acute respiratory infections. Сephalosporins were administered intravenously in age doses. We evaluated the biochemical blood test and the echosonography (ultrasound of the biliary tract before the treatment and after the end of antibiotic therapy of all children. Results. According to ultrasound data, in 10 patients (21.7 % with acute respiratory infections, after a course of therapy with the third generation cephalosporins, heterogeneous contents were detected in the gallbladder lumen in the form of a hyperechoic suspension, which indicated the formation of CIBPL. The average age of patients with CIBPL was 9.05 ± 1.44 years and was within the range of 4 to 15 years. We found that in 60 % of the examined children, the formation of CIBPL proceeded subclinically. The results of a biochemical study of blood serum showed that in children with CIBPL, an increase in the activity of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase was observed. It was found that CIBPL is detected in 22.9 % of children against the background of ceftriaxone therapy, in 9 % of patients — ceftazidime. Biliary sludge was formed in 54.5 % of patients receiving ceftriaxone in high doses (100 mg/kg/day, and in 75 % of cases after 10 days of using this antibiotic. Conclusions. The obtained results showed that against the background of using third generation cephalosporins in the treatment of acute respiratory infections, 21.7 % of children had CIBPL. A particularly high risk of developing CIBPL is observed when

  3. Electrodialytic recovery of phosphorus from chemically precipitated sewage sludge ashes

    DEFF Research Database (Denmark)

    Viader, Raimon Parés; Erland Jensen, Pernille; Ottosen, Lisbeth M.

    Phosphorus scarcity requires improved recover and reuse of urban sources; the recycling of this nutrient from sewage sludge has become increasingly important in the last years. Using an innovative electrodialytic process, the present study shows the potential for P separation from Fe and Al preci...... precipitated sewage sludge ash using this technique, with a recovery rate of around 70%. Furthermore, heavy metals were removed from the phosphorous fraction, producing a pure and safe phosphorus source in the end...

  4. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.


    The Activated Sludge Model No. 2d (ASM2d) presents a model for biological phosphorus removal with simultaneous nitrification-denitrification in activated sludge systems. ASM2d is based on ASM2 and is expanded to include the denitrifying activity of the phosphorus accumulating organisms (PAOs......). This extension of ASM2 allows for improved modeling of the processes, especially with respect to the dynamics of nitrate and phosphate. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  5. Recovery of valuable products from municipal wastewater sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cassidy, S. [Kemira Kemi AB, Kemwater, Helsingborg (Sweden)


    Municipal wastewater sludge is a complex product containing both valuable substances as well as contaminants. The valuable substances are: (i) Phosphorus, (ii) Organic matter, and (iii) Coagulants. The contaminants include heavy metals and organic micro-pollutants. With increasing wastewater volumes and advanced wastewater treatment processes, sludge production continues to grow and with it, the volumes of contaminated sludge which is not suitable for arable land. This will have an unacceptable, negative impact on the environment. This is why new sustainable sludge treatment technologies/disposal alternatives have become so interesting. Kemwater`s KREPRO-process is a process which can re-use valuable substances from sludge. In this process, three different products, namely, organic sludge, a phosphorus salt and a carbon source are produced. The organic sludge had a dry solids content of around 50% which makes it suitable for energy production. The heat value in the sludge is dependent on the dry solids content. This value of around 8 MJ/kg was found to be similar to that of wood-chips. The phosphorus salt has a low content of contaminants and is therefore suitable for use as a fertiliser. Its lower solubility compared to that of artificial fertilisers, however, makes the phosphorus less available to plants. This was supported in both field and pot trials, which suggested that the phosphorus is available, but not to the same extent as with artificial fertilisers. The carbon source contains easily degradable COD and coagulants. The COD was tested as a carbon source for increasing both denitrification and biological phosphorus removal. The results showed that the carbon source is good for both applications, although not as good as acetate. (orig.)

  6. Recovery of indigenous enteroviruses from raw and digested sewage sludges.


    Goddard, M R; Bates, J; Butler, M


    We examined different types of raw sewage sludge treatment, including consolidation, anaerobic mesophilic digestion with subsequent consolidation, and aerobic-thermophilic digestion. Of these, the most efficient reduction in infectious virus titer was achieved by mesophilic digestion with subsequent consolidation, although a pilot-scale aerobic-thermophilic digester was extremely time effective, producing sludges with similarly low virus titers in a small fraction of the time. Although none o...

  7. A study of paint sludge deactivation by pyrolysis reactions


    L.A.R. Muniz; Costa, A. R. [UNESP; E. Steffani; Zattera,A.J.; Hofsetz, K; K. Bossardi; Valentini, L.


    The production of large quantities of paint sludge is a serious environmental problem. This work evaluates the use of pyrolysis reaction as a process for deactivating paint sludge that generates a combustible gas phase, a solvent liquid phase and an inert solid phase. These wastes were classified into three types: water-based solvent (latex resin) and solvents based on their resins (alkyd and polyurethane). An electrically heated stainless steel batch reactor with a capacity of 579 mL and a m...

  8. Karakteristik Briket Arang dari Sludge dengan Penambahan Arang Tempurung Kelapa


    Gultom, Juliana Frisca


    Sludge is solid wasted from pulp and paper industries as a potential material for the manufacture of briquetted charcoal. The purpose of this study is to examine the characteristic of briquetted charcoal from sludge and the optimalize of physical and mechanichal properties when the add of the coconut shell. The add of the coconut shell is variated from 10%, 15%, 20% and 25% based on the weight of briquetted charcoal. Carbonization process on coconut shell was using simple kiln and frying meth...

  9. Analysis of lagoon sludge characteristics for choice of treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. H.; Hwang, D. S.; Choi, Y. D.; Lee, K. I.; Hwang, S. T.; Jung, K. J. [Korea Atomic Energy Research Institute, Taejeon (Korea)


    The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and impurities of the yellow cake. The content of uranium, thorium and Ra-226 was high in pond-1 and low in pond-2 because those were removed during Ca precipitation. On the base of the characteristics of the sludge and available technologies, reviewed in this study and being developed in Korea Atomic Energy Research Institute, two processes were proposed and evaluated in points of the expected technological difficulties. And the cost for treatment of sludges are estimated for both processes. 79 refs., 44 figs., 37 tabs. (Author)

  10. Properties of fired clay brick incorporating with sewage sludge waste (United States)

    Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Sarani, Noor Amira; Rahmat, Nur Aqma Izurin; Abdullah, Mohd Mustafa Al Bakri


    The production of sludge in wastewater treatment plant is about to increase every year and most of the sludge was directly disposed to landfill. In addition, the constraint to treat sludge is very high in cost and time- consuming could be disadvantages to the responsible parties. Therefore, this research was conducted to utilize sludge produced from the wastewater treatment plant into fired clay brick as one of the alternatives of disposal method. In this study, the research attempt to incorporate sewage sludge waste (SSW) into fired clay brick. The sewage sludge brick (SSB) mixtures were incorporated with 0%, 1%, 5%, 10%, and 20% of SSW. The manufactured bricks were fired at 1050°C with heating rate of 1°C/min. Physical and mechanical properties test were conducted such as shrinkage, density, water absorption and compressive strength. As the conclusion, brick with utilization 5% of SSW is acceptable to produce good quality of brick. This study shows by using SSW in fired clay brick could be an alternative method to dispose of the SSW and also could act as a replacement material for brick manufacturing with appropriate mix and design.

  11. Particleboard manufacturing: an innovative way to recycle paper sludge. (United States)

    Taramian, Asghar; Doosthoseini, Kazem; Mirshokraii, Sayyed Ahmad; Faezipour, Mehdei


    This paper presents the results on a study to use paper mill sludge for particleboard production. Single-layer board and three-layer board, with paper sludge on the surface, were fabricated. Four levels of mixing ratios of paper sludge to wood particles (0:100, 15:85, 30:70, and 45:55) were used. The boards were produced with 3% and 4% methylene diphenyl diisocyanate (MDI), and 10% and 12% urea-formaldehyde (UF) adhesives. The bending and shear strengths, water absorption, and thickness swelling of the boards were investigated. The results indicated that the mechanical properties of the boards were negatively affected by the paper sludge amount. Overall, UF-bonded particleboards gave superior mechanical performance, water resistance, and thickness swell than MDI-bonded particleboards. The strengths of the UF-bonded board decreased much more than those of MDI-bonded board as paper sludge content increased. The three-layer boards made from 15% paper sludge with 12% UF satisfied fully the minimum requirements set by EN, ASTM D 1037-99, and ANSI A208.1 standards for general uses.


    Energy Technology Data Exchange (ETDEWEB)



    Highly radioactive sludge (containing up to 300,000 curies of actinides and fission products) resulting from the storage of degraded spent nuclear fuel is currently stored in temporary containers located in the 105-K West storage basin near the Columbia River. The background, history, and known characteristics of this sludge are discussed in Section 2 of this report. There are many compelling reasons to remove this sludge from the K-Basin. These reasons are discussed in detail in Section1, and they include the following: (1) Reduce the risk to the public (from a potential release of highly radioactive material as fine respirable particles by airborne or waterborn pathways); (2) Reduce the risk overall to the Hanford worker; and (3) Reduce the risk to the environment (the K-Basin is situated above a hazardous chemical contaminant plume and hinders remediation of the plume until the sludge is removed). The DOE-RL has stated that a key DOE objective is to remove the sludge from the K-West Basin and River Corridor as soon as possible, which will reduce risks to the environment, allow for remediation of contaminated areas underlying the basins, and support closure of the 100-KR-4 operable unit. The environmental and nuclear safety risks associated with this sludge have resulted in multiple legal and regulatory remedial action decisions, plans,and commitments that are summarized in Table ES-1 and discussed in more detail in Volume 2, Section 9.

  13. Sewage sludge as substrate for Tectona grandis L. seedlings production

    Directory of Open Access Journals (Sweden)

    Daniele Rodrigues Gomes


    Full Text Available The sewage sludge is a waste from sewage treatment plants, which can be used in formulations of substrates for seedling production. This study aimed to evaluate the effects of different proportions of sewage sludge, soil and commercial substrate on the growth characteristics of Tectona grandis seedlings in tubes of 120 cm³ volume capacity. The sewage sludge used came from the STP's Cachoeiro de Itapemirim / ES. The seedlings were grown in the forest nursery / CCA / UFES. The statistical design used in the experiment was completely randomized design (CRD with six treatments and five replications. The treatments constituted of sewage sludge : commercial substrate: soil (v: v: v, which corresponded to 20:70:10 (T1, 40:50:10 (T2, 60:30:10 (T3, 80 : 10:10 (T4, 90:0:10 (T5 and the control treatment with 0:90:10 (T6. All variables assessed were significant at the 5% level of probability. The control (T6 showed results statistically equal to or lower than the treatments T3 with 60% of sewage sludge concentration (T3. It follows then that the use of sewage sludge in seedling production is feasible and promising, however, used in a proper proportion.

  14. Sludge as dioxins suppressant in hospital waste incineration. (United States)

    Yan, Mi; Li, Xiaodong; Yang, Jie; Chen, Tong; Lu, Shengyong; Buekens, Alfons G; Olie, Kees; Yan, Jianhua


    Nitrogen containing compounds such as ammonia, urea and amines can effectively inhibit the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Sewage sludge accumulates both sulfur and nitrogen during wastewater treatment so it could be used to reduce PCDD/Fs formation. Indeed, it is observed in this study that the gas evolving from the sludge drying process can significantly suppress chlorobenzene (CBz) and PCDD/Fs formation from fly ash collected from a hospital waste incinerator. For instance, the reduction of hexachlorobenzene (HxCBz) and PCDD/Fs amount was 92.1% and 78.7%, respectively, when the drying gas evolving from 2g sludge flew through 2g fly ash. These tests were conducted in the frame of projects devoted to hospital waste incineration. The disposal technology for hospital waste (HW), developed in this institute, features rotary kiln pyrolysis combined with post-combustion followed by flue gas cleaning. Hence, some preliminary tests were devoted to investigate dioxins suppression by co-pyrolysis and co-combustion of polyvinyl chloride (PVC) and sludge in lab scale. More experimental research will be conducted to appropriately assess these effects of sludge on PCDD/Fs emissions during co-pyrolysis/combustion of HW and sludge. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Organochlorine pesticides and polychlorinated biphenyls in sewage sludge from Egypt. (United States)

    Barakat, Assem O; Khairy, Mohammed A; Mahmoud, Mahmoud R


    The purpose of this study was to determine the levels, distribution and toxicological potential of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in sewage sludge samples from several WWTPs in the Alexandria area, Egypt. The POPs of interest were 26 PCBs and 16 OCPs. Analyses were performed by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM) using deuterated organochlorines as internal standards. Total concentrations of OCPs and Σ7 PCBs (ICES) in sludge ranged from 44.2 to 489 μg/kg dw. and 5,600 to 11,000 μg/kg dw., respectively. The highest concentration levels were found for PCBs, HCHs, DDTs, and HCB, in this order. The PCB homologue profiles in sludge samples were dominated by penta- and hexa-chlorinated biphenyls. Seasonal variations were observed for OCPs with higher levels in summer, which reflects more usage in warmer climates. Composite profiles of OCP metabolites indicated new inputs of lindane and technical endosulfan and earlier usage of DDT and technical chlordane. Contamination levels of OCPs and PCBs for Egyptian sludge can be categorized as moderate to high compared to other countries worldwide. The OCP content in none of the samples exceeded limits set by the European Commission for use of sludge in agriculture; while all the concentrations of PCBs in sludge samples were higher by one order of magnitude than the upper limit for land application.

  16. Pretreatment methods as a means of boosting methane production from sewage sludge and its mixtures with grease trap sludge (United States)

    Grosser, Anna; Neczaj, Ewa


    The main objective of this study was to determine the applicability of the selected pretreatment methods as a means of intensification of methane production from sewage sludge as well as its mixtures with grease trap sludge. The addition of the fat rich material to the digester treating sewage sludge resulted in an increased methane yield as well as volatile solids (VS) removal of up to 36% (from 134.75 mL/g VS to 182.84 mL/g VS). Furthermore, thermochemical pretreatment of the co-digestion mixture resulted in an approximately 76% higher methane yield as compared to the untreated sewage sludge. The energy balance showed that, for both materials ultrasonic pretreatment and thermochemical pretreatment has an energy self-sufficiency. All of the tested models fit the experimental data with coefficients of determination higher than 0.96.

  17. Pretreatment methods as a means of boosting methane production from sewage sludge and its mixtures with grease trap sludge

    Directory of Open Access Journals (Sweden)

    Grosser Anna


    Full Text Available The main objective of this study was to determine the applicability of the selected pretreatment methods as a means of intensification of methane production from sewage sludge as well as its mixtures with grease trap sludge. The addition of the fat rich material to the digester treating sewage sludge resulted in an increased methane yield as well as volatile solids (VS removal of up to 36% (from 134.75 mL/g VS to 182.84 mL/g VS. Furthermore, thermochemical pretreatment of the co-digestion mixture resulted in an approximately 76% higher methane yield as compared to the untreated sewage sludge. The energy balance showed that, for both materials ultrasonic pretreatment and thermochemical pretreatment has an energy self-sufficiency. All of the tested models fit the experimental data with coefficients of determination higher than 0.96.

  18. Conversion of sludges into ''topsoils'' by earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M.J.

    Two of three anaerobically digested secondary treatment sludges were toxic to the redworm Eisenia foetida, while a third was not as ravenously consumed as an aerobically digested secondary treatment sludge. Toxicity disappeared when the sludges were allowed to age for two months or more at room temperature as a 2-3 cm layer exposed to air. The reduced toxicity was achieved in order to allow the earthworms to convert the sludge into topsoil. By feeding about 20 gm of earthworms the equivalent of 100 gm of sludge during four weeks brought the sludges about 5% of the way toward being a stable mineral soil. (9 references, 1 table)

  19. Self-heating co-pyrolysis of excessive activated sludge with waste biomass: energy balance and sludge reduction. (United States)

    Ding, Hong-Sheng; Jiang, Hong


    In this work, co-pyrolysis of sludge with sawdust or rice husk was investigated. The results showed that the co-pyrolysis technology could be used to dispose of the excessive activated sludge without external energy input. The results also demonstrated that no obvious synergistic effect occurred except for heat transfer in the co-pyrolysis if the co-feeding biomass and sludge had similar thermogravimetric characteristics. The experimental results combined with calculation showed that adding sawdust accounting for 49.6% of the total feedstock or rice husk accounting for 74.7% could produce bio-oil to keep the energy balance of the co-pyrolysis system and self-heat it. The sludge from solar drying bed can be further reduced by 38.6% and 35.1% by weight when co-pyrolyzed with rice husk and sawdust, respectively. This study indicates that sludge reduction without external heat supply through co-pyrolysis of sludge with waste biomass is practically feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Sustainable use of tannery sludge in brick manufacturing in Bangladesh. (United States)

    Juel, Md Ariful Islam; Mizan, Al; Ahmed, Tanvir


    Chromium-rich tannery sludge generated from tanneries has the potential to become a serious environmental burden in Bangladesh and a promising avenue for disposal of this sludge is by stabilizing it in clay brick products. But for sustainable industrial application of such technique it needs to be ensured first that the engineering properties of bricks as a building material are not diminished by addition of sludge, the process becomes energy efficient compared to alternatives and the use of such bricks do not pose any harmful environmental effects in the long run. In this study, clay bricks were prepared with different proportions of sludge (10%, 20%, 30% and 40% by dry weight) in both laboratory-controlled and field conditions and their suitability as a construction material was assessed based on their strength, water absorption, shrinkage, weight-loss on ignition and bulk density. For the sludge incorporated bricks, the compressive strength ranged from 10.98MPa to 29.61MPa and water absorption ranged from 7.2% to 20.9%, which in most cases met both the Bangladesh and ASTM criteria for bricks as a construction material. Volumetric shrinkage, weight loss and efflorescence properties of sludge-amended bricks were found to be favorable and it was estimated that an energy saving of 15-47% could potentially be achieved during firing with 10-40% tannery sludge-amended bricks. The quality of sludge-amended bricks made in the brick kiln was relatively inferior compared to bricks produced in the laboratory due to operating in a less-controlled environment with respect to maintaining adequate compaction and optimum moisture content. The leaching behavior of several heavy metals (Cr, As, Cu, Ni, Cd, Pb and Zn) from sludge-amended bricks has been found to be insignificant and far below the Dutch regulations and USEPA regulatory limits. Results from this study indicate that tannery sludge can be sustainably stabilized in clay bricks and large-scale application of this

  1. Sludge Washing and Demonstration of the DWPF Nitric/Formic Flowsheet in the SRNL Shielded Cells for Sludge Batch 9 Qualification

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martino, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Johnson, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to qualify the next batch of sludgeSludge Batch 9 (SB9). Current practice is to prepare sludge batches in Tank 51 by transferring sludge to Tank 51 from other tanks. The sludge is washed and transferred to Tank 40, the current Defense Waste Process Facility (DWPF) feed tank. Prior to sludge transfer from Tank 51 to Tank 40, the Tank 51 sludge must be qualified. SRNL qualifies the sludge in multiple steps. First, a Tank 51 sample is received, then characterized, washed, and again characterized. SRNL then demonstrates the DWPF Chemical Process Cell (CPC) flowsheet with the sludge. The final step of qualification involves chemical durability measurements of glass fabricated in the DWPF CPC demonstrations. In past sludge batches, SRNL had completed the DWPF demonstration with Tank 51 sludge. For SB9, SRNL has been requested to process a blend of Tank 51 and Tank 40 at a targeted ratio of 44% Tank 51 and 56% Tank 40 on an insoluble solids basis.

  2. Nitrogen mineralisation and greenhouse gas emission from the soil application of sludge from reed bed mineralisation systems

    DEFF Research Database (Denmark)

    Gómez-Muñoz, B; Larsen, Julie Dam; Bekiaris, G


    A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time (stabilisa......A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time...

  3. Sludge application and monitoring program on the Oak Ridge Reservation, 1986--1993

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, C.A.; Larsen, I.L.; Boston, H.L.; Bradburn, D.M. [Oak Ridge National Lab., TN (United States); Van Miegroet, H. [Utah State Univ., Logan, UT (United States). Dept. of Forest Resources; Morris, J.L. [Jaycor, Inc., Oak Ridge, TN (United States); Walzer, A.E. [Lockheed Martin Energy Systems, Oak Ridge, TN (United States). Central Environmental Compliance; Adler, T.C. [Bechtel National, Inc., Oak Ridge, TN (United States); Huq, M. [Oak Ridge Associated Universities, TN (United States)


    Municipal sewage sludge has been applied to forests and pastures on the Oak Ridge Reservation since 1983 as a method of both disposal and beneficial reuse. Application was carried out under Tennessee permits issued to the city of Oak Ridge for land disposal of sewage sludge. In conjunction with these applications, information has been collected concerning sludge quantity and characteristics, soil parameters, soil water constituents, groundwater quality, surface runoff water quality, and various chemical constituents in vegetation on application sites. This information provides (1) a record of sludge application on the DOE reservations and (2) documentation of changes in soil parameters following sludge application. The information also provides a basis for evaluating the implications of the land application of municipal sewage sludge for soil and water quality and for evaluating the fate of sludge constituents when sludge is either sprayed or injected on pasture sites or surface applied in forested sites. This report covers in detail sludge applications conducted from 1986 through 1993, with some data from the period between 1983 and 1986. Anaerobically digested liquid sludge (2% to 4% solids) from the city of Oak Ridge had a relatively high nitrogen content (8% dry weight) and average to low concentrations of potentially problematic metals, compared with typical municipal sludges. Few potentially hazardous organic chemicals were detected in the sludge, and when found, these were at very low concentrations. Oak Ridge sludge is somewhat unique in that it contains radionuclides ({sup 137}Cs, {sup 60}Co, {sup 131}I, uranium isotopes, {sup 90}Sr, and occasionally {sup 99}Tc) at concentrations much higher than typical municipal sludges. Land application of sewage sludge can dilute or destroy problematic sludge constituents while improving soil fertility. Correct management has made these sludge applications a model of environmentally responsible waste management.


    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J.; Billings, A.; Click, D.


    Waste Solidification Engineering (WSE) has requested that characterization and a radioactive demonstration of the next batch of sludge slurry (Sludge Batch 7a*) be completed in the Shielded Cells Facility of the Savannah River National Laboratory (SRNL) via a Technical Task Request (TTR). This characterization and demonstration, or sludge batch qualification process, is required prior to transfer of the sludge from Tank 51 to the Defense Waste Processing Facility (DWPF) feed tank (Tank 40). The current WSE practice is to prepare sludge batches in Tank 51 by transferring sludge from other tanks. Discharges of nuclear materials from H Canyon are often added to Tank 51 during sludge batch preparation. The sludge is washed and transferred to Tank 40, the current DWPF feed tank. Prior to transfer of Tank 51 to Tank 40, SRNL simulates the Tank Farm and DWPF processes with a Tank 51 sample (referred to as the qualification sample). Sludge Batch 7a (SB7a) is composed of portions of Tanks 4, 7, and 12; the Sludge Batch 6 heel in Tank 51; and a plutonium stream from H Canyon. SRNL received the Tank 51 qualification sample (sample ID HTF-51-10-125) following sludge additions to Tank 51. This report documents: (1) The washing (addition of water to dilute the sludge supernate) and concentration (decanting of supernate) of the SB7a - Tank 51 qualification sample to adjust sodium content and weight percent insoluble solids to Tank Farm projections. (2) The performance of a DWPF Chemical Process Cell (CPC) simulation using the washed Tank 51 sample. The simulation included a Sludge Receipt and Adjustment Tank (SRAT) cycle, where acid was added to the sludge to destroy nitrite and reduce mercury, and a Slurry Mix Evaporator (SME) cycle, where glass frit was added to the sludge in preparation for vitrification. The SME cycle also included replication of five canister decontamination additions and concentrations. Processing parameters were based on work with a non

  5. Anaerobic treatment of sludge: focusing on reduction of LAS concentration in sludge

    DEFF Research Database (Denmark)

    Haagensen, Frank; Mogensen, Anders Skibsted; Angelidaki, Irini


    between transformed and bioavailable LAS12 was found, indicating that it is merely the bioavailable fraction of LAS12 that is transformed by anaerobic digestion. The results from the present study are promising and indicate that a great potential for biological degradation of LAS is possible even......Anaerobic degradation of linear alkylbenzene sulfonates (LAS) was tested in continuous stirred tank reactors (CSTR). LAS12 was used as a model compound and was spiked on sewage sludge. The experiments clearly showed that transformation of LAS12 occurred under anaerobic conditions. The degree...... at anaerobic conditions....

  6. Anaerobic bioleaching of metals from waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Meulepas, Roel J.W., E-mail: [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)


    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  7. Heavy metal speciation and toxicity characteristics of tannery sludge (United States)

    Juel, Md. Ariful Islam; Chowdhury, Zia Uddin Md.; Ahmed, Tanvir


    Heavy metals present in tannery sludge can get mobilized in the environment in various forms and can be a cause for concern for the natural ecosystem and human health. The speciation of metals in sludge provides valuable information regarding their toxicity in the environment and determines their suitability for land application or disposal in landfills. Concentrations of seven heavy metals (Cr, Pb, Cd, Ni, Zn, As and Cu) in tannery sludge were determined to evaluate their toxicity levels. Metal contents ranged over the following intervals: As: 1.52-2.07 mg/kg; Pb: 57.5-67 mg/kg; Cr: 15339-26501 mg/kg; Cu: 261.3-579.5 mg/kg; Zn: 210.2-329.1 mg/kg and Ni: 137.5-141.3 mg/kg (dry weight basis). The concentrations of all heavy metals in the sludge samples were lower compared to EPA guidelines except chromium which was found to be several orders of magnitude higher than the guideline value. Toxicity Characteristics Leaching Procedure (TCLP) test indicated that the leaching potential of chromium was higher compared to the other heavy metals and exceeded the EPA land disposal restriction limits. To quantitatively assess the environmental burden of the chromium associated with tannery sludge, the IMPACT 2002+ methodology was adopted under the SimaPro software environment. Considering the USEPA limit for chromium as the baseline scenario, it was found that chromium in the tannery sludge had 6.41 times higher impact than the baseline in the categories of aquatic ecotoxicity, terrestrial ecotoxicity and non-carcinogens. Chromium has the highest contribution to toxicity in the category of aquatic ecotoxicity while copper is the major contributor to the category of terrestrial ecotoxicity in the tannery sludge.

  8. K Basin sludge polychlorinated biphenyl removal technology assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, S.C.


    The two Hanford K Basins are water-filled concrete pools that contain over 2,100 metric tons of N Reactor fuel elements stored in aluminum or stainless steel canisters. During the time the fuel has been stored, approximately 50 m3 of heterogeneous solid material have accumulated in the basins. This material, referred to as sludge, is a mixture of fuel corrosion products, metallic bits of spent fuel and zirconium clad iron and metal corrosion products and silica from migrating sands. Some of the sludges also contain PCBs. The congener group of PCBs was identified as Aroclor 1254. The maximum concentration of sludge PCBS was found to be 140 ppm (as settled wet basis). However, the distribution of the PCBs is non-uniform throughout the sludge (i.e., there are regions of high and low concentrations and places where no PCBs are present). Higher concentrations could be present at various locations. Aroclors 1016/1242, 1221, 1248, 1254, and 1260 were identified and quantified in K West (KW) Canister sludge. In some of these samples, the concentration of 1260 was higher than 1254. The sludge requires pre-treatment to meet tank farm waste acceptance criteria, Among the numerous requirements, the sludge should be retreated so that it does not contain regulated levels of Toxic Substances Control Act (TSCA) compounds. Because of their stable chemistry and relative insolubility in water, PCBs are difficult to treat. They also resist degradation from heat and electrical charges. This stability has resulted in environmental persistence which has prompted the development of a variety of new cleanup processes including supercritical processes, advanced oxidation, dehalogenation and others. Hopefully, most of the new processes are discussed herein. Information on new processes are being received and will be evaluated in a future revision.

  9. Modified sewage sludge as temporary landfill cover material

    Directory of Open Access Journals (Sweden)

    Jun He


    Full Text Available In order to study the feasibility of modified sewage sludge as landfill cover material and its performance in a complex landfill environment, strength and hydraulic conductivity tests were conducted. The permeability requirements for daily and interim covers were analyzed first. Based on saturated-unsaturated seepage calculations, it is suggested that approximately 1.0 × 10−4 cm/s and 1.0 × 10−5 cm/s are the appropriate values for the hydraulic conductivities of daily and interim covers, respectively. The strength and permeability requirements of the mixtures, when used as an interim cover, can be met at a sludge:lime:cement:silt:tire-derived aggregate (TDA weight ratio of 100:15:5:70:15. Results also demonstrate that the solid content ratio of modified sewage sludge, which should be greater than 60% when modified sewage sludge is used as a temporary cover material, is crucial to both strength and hydraulic performance. In addition, as the duration of soaking of modified sewage sludge in synthetic leachate increases, the unconfined compressive strength increases, and the hydraulic conductivity decreases slightly or fluctuates between 1.0 × 10−5 cm/s and 1.0 × 10−6 cm/s, still meeting the requirements for an interim cover. The reduction in hydraulic conductivity of modified sewage sludge under the effect of synthetic leachate, as well as the long-term and environmental performance of the modified sewage sludge, should be examined in future studies.

  10. Modelling of Activated Sludge Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Kurtanjeka, Ž.


    Full Text Available Activated sludge wastewater treatment is a highly complex physical, chemical and biological process, and variations in wastewater flow rate and its composition, combined with time-varying reactions in a mixed culture of microorganisms, make this process non-linear and unsteady. The efficiency of the process is established by measuring the quantities that indicate quality of the treated wastewater, but they can only be determined at the end of the process, which is when the water has already been processed and is at the outlet of the plant and released into the environment.If the water quality is not acceptable, it is already too late for its improvement, which indicates the need for a feed forward process control based on a mathematical model. Since there is no possibility of retracing the process steps back, all the mistakes in the control of the process could induce an ecological disaster of a smaller or bigger extent. Therefore, models that describe this process well may be used as a basis for monitoring and optimal control of the process development. This work analyzes the process of biological treatment of wastewater in the Velika Gorica plant. Two empirical models for the description of the process were established, multiple linear regression model (MLR with 16 predictor variables and piecewise linear regression model (PLR with 17 predictor variables. These models were developed with the aim to predict COD value of the effluent wastewater at the outlet, after treatment. The development of the models is based on the statistical analysis of experimental data, which are used to determine the relations among individual variables. In this work are applied linear models based on multiple linear regression (MLR and partial least squares (PLR methods. The used data were obtained by everyday measurements of the quantities that indicate the quality of the input and output water, working conditions of the plant and the quality of the activated sludge

  11. Recycling of stone cutting sludge in formulations of bricks and terrazzo tiles. (United States)

    Al-Zboon, Kamel; Tahat, Montasser; Abu-Hamatteh, Ziad S H; Al-Harahsheh, Mohammad S


    This study examines the possibility for enhancing the use of stone cutting sludge waste in the production of building bricks and terrazzo tiles, which would reduce both the environmental impact and the production costs. Stone cutting wastes in the form of sludge is currently generated at several factories in Jordan. At the Samara factory, incorporation of the sludge in the batch formulations of bricks and terrazzo tiles was examined. The physicochemical and mineralogical characteristics of the sludge were analyzed to identify the major components. Results indicated that the sludge generated from stone cutting could be used in producing concrete bricks. Mixtures of aggregates with added amounts of sludge were used successfully to produce non-load bearing bricks. Sludge was also used to produce terrazzo tiles and the results indicate that the transverse strength, water absorption and tile measurements, for all the taken samples, comply with Jordanian standards. The transverse strength decreased while water absorption increased as the sludge ratio increased.

  12. Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogen production. (United States)

    Yu, Li; Yu, Yang; Jiang, Wentian; Wei, Huangzhao; Sun, Chenglin


    The increasing sludge generated in wastewater treatment plants poses a threat to the environment. Based on the traditional processes, sludge dewatered by usual methods was further dewatered by hydraulic compression and the filtrate released was treated by anaerobic fermentation. The difficulties in sludge dewatering were associated with the existence of sludge flocs or colloidal materials. A suitable CaO dosage of 125 mg/g dry sludge (DS) could further decrease the moisture content of sludge from 82.4 to 50.9 %. The filtrate from the dewatering procedure was a potential substrate for biohydrogen production. Adding zero-valent iron (ZVI) into the anaerobic system improved the biohydrogen yield by 20 %, and the COD removal rate was lifted by 10 % as well. Meanwhile, the sludge morphology and microbial community were altered. The novel method could greatly reduce the sludge volume and successfully treated filtrate along with the conversion of organics into biohydrogen.

  13. Study on improvement of sludge dewaterability with H2O2 cell lysis (United States)

    Zhuo, Qiongfang; Yi, Hao; Zhang, Zhengke; Wang, Ji; Feng, Lishi; Xu, Zhencheng; Guo, Qingwei; Jin, Zhong; Lan, Yongzhe


    Excess sludge is the product of sewage treatment plants. With continuous perfection of municipal sewage treatment facilities in China, sludge output increases as a result of the growth of sewage treatment plants. Excess sludge has complicated compositions, including heavy metals, PPCPs, persistent organic pollutants. It owns high contents of organic matters and water. High-efficiency and low-cost dehydration of sludge is the key of sludge disposal. How to improve sludge dehydration efficiency is the research hotspot in the world. In this study, effects of hydrogen peroxide content and pH on sludge dehydration were discussed by chemical disintegration technique. The optimal hydrogen peroxide content and pH were discussed, aiming to search a high-efficiency sludge conditioner.

  14. Growth, yield and fruit quality of pepper plants amended with two sanitized sewage sludges


    Pascual Elizalde, Inmaculada; Azcona, Iñaki; Aguirreolea, Jone; Morales Iribas, Fermín; Corpas, Francisco Javier; Palma, José Manuel; Rellán-Álvarez, Rubén; Sánchez-Díaz, Manuel


    Organic wastes such as sewage sludge have been successfully used to increase crop productivity of horticultural soils. Nevertheless, considerations of the impact of sludges on vegetable and fruit quality have received little attention. Therefore, the objective of the present work was to investigate the impact of two sanitized sewage sludges, autothermal thermophilic aerobic digestion (ATAD) and compost sludge, on the growth, yield, and fruit quality of pepper plants (Capsicum annuum L. cv. Pi...

  15. Feasibility report on criticality issues associated with storage of K Basin sludge in tanks farms

    Energy Technology Data Exchange (ETDEWEB)

    Vail, T.S.


    This feasibility study provides the technical justification for conclusions about K Basin sludge storage options. The conclusions, solely based on criticality safety considerations, depend on the treatment of the sludge. The two primary conclusions are, (1) untreated sludge must be stored in a critically safe storage tank, and (2) treated sludge (dissolution, precipitation and added neutron absorbers) can be stored in a standard Double Contained Receiver Tank (DCRT) or 241-AW-105 without future restrictions on tank operations from a criticality safety perspective.

  16. Combustion of sewage sludge water in Netherland; Incineracion de lodos procedentes de aguas residuales en Holanda

    Energy Technology Data Exchange (ETDEWEB)

    Viles, A. W. van der


    The Dutch policy for sewage sludge disposal has been changed in the last decades. Instead of predominantly beneficial use thermal processes, such as sludge drying and incineration, will become increasely more necessary. These processes are subject to very strict environmental regulations. Sludge incineration has to meet the very strict flue gas emission requirements of the Dutch Guideline on Incineration. The consequences for a new sludge incineration plant are reviewed.

  17. Sludge Treatment and Extraction Technology Development: Results of FY 1993 studies

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, G.J.; Wagner, M.J.; Barrington, R.J.; Rapko, B.M.; Carlson, C.D.


    This report describes experimental results from work conducted in FY 1993 under the Sludge Treatment and Extraction Technology Development Task of the Tank Waste Remediation System (TWRS) Pretreatment Technology Development Project at Pacific Northwest Laboratory (PNL). Experiments were conducted in the following six general areas: (1) sludge washing, (2) sludge leaching, (3) sludge dissolution, (4) actinide separation by solvent extraction and extraction chromatography, (5) Sr separation by solvent extraction, and (6) extraction of Cs from acidic solution.

  18. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Yuancai, E-mail: [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Chen, Yuancai, E-mail: [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Song, Wenzhe, E-mail: [Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Hu, Yongyou, E-mail: [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China)


    Graphical abstract: In this work, an aerobic column reactor was placed before the USB to maintain micro-oxygen condition in the reactor and the micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) was successfully obtained. PCP degradation by the micro-aerobic system was studied and the variance of microbial community was also discussed by using PCR-DGGE analysis. - Highlights: • Micro-aerobic granular sludge was cultivated in column-type combined reactors. • PCP biodegradation, VFA accumulation and biogas production were studied. • The function of Methanogenic archaeon in the system was investigated. • Fluctuation and diversity of microbial community were discussed by DGGE analysis. • The dominated microorganisms were identified by 16S rDNA sequences. - Abstract: Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH{sub 4}/h g VSS) and aerobic activity (SOUR: 2.21 mMO{sub 2}/h g VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro

  19. Anaerobic sludge digestion with a biocatalytic additive

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S.; Henry, M.P.; Fedde, P.A.


    The objective of this research was to evaluate the effects of a lactobacillus additive an anaerobic sludge digestion under normal, variable, and overload operating conditions. The additive was a whey fermentation product of an acid-tolerant strain of Lactobacillus acidophilus fortified with CaCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid. The lactobacillus additive is multifunctional in nature and provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. The experimental work consisted of several pairs of parallel mesophilic (35/sup 0/C) digestion runs (control and test) conducted in five experimental phases. Baseline runs without the additive showed that the two experimental digesters had the same methane content, gas production rate (GPR), and ethane yield. The effect of the additive was to increase methane yield and GPR by about 5% (which was statistically significant) during digester operation at a loading rate (LR) of 3.2 kg VS/m/sup 3/-day and a hydraulic retention time (HRT) of 14 days. Data collected from the various experimental phases showed that the biochemical additive increased methane yield, gas production rate, and VS reduction, and decreased volatile acids accumulation. In addition, it enhanced digester buffer capacity and improved the fertilizer value and dewatering characteristics of the digested residue.

  20. Sludge cleaning in the steam generators: sludge Lancing e IBL; Limpieza de lodos en los generadores de vapor: Sludge Lancing IBL

    Energy Technology Data Exchange (ETDEWEB)

    Montoro, E.; Gonzalez, S.; Calderon, N.


    IBERDROLA Engineering and Construction has echoed the need for plants to remove oxide deposits (sludge) located on the secondary side, on the bottom plate and into the tube bundle steam steam generators. Therefore, and with its partner SAVAC SRA has developed a specific system consisting of applying a capillary water at very high pressure applied directly to the location of these oxides. (Author)

  1. Microwave pyrolysis of oily sludge with activated carbon. (United States)

    Chen, Yi-Rong


    The aim of this study is to explore catalytic microwave pyrolysis of crude oil storage tank sludge for fuels using granular activated carbon (GAC) as a catalyst. The effect of GAC loading on the yield of pyrolysis products was also investigated. Heating rate of oily sludge and yield of microwave pyrolysis products such as oil and fuel gas was found to depend on the ratio of GAC to oily sludge. The optimal GAC loading was found to be 10%, while much smaller and larger feed sizes adversely influenced production. During oily sludge pyrolysis, a maximum oil yield of 77.5% was achieved. Pyrolytic oils with high concentrations of diesel oil and gasoline (about 70 wt% in the pyrolytic oil) were obtained. The leaching of heavy metals, such as Cr, As and Pb, was also suppressed in the solid residue after pyrolysis. This technique provides advantages such as harmless treatment of oily sludge and substantial reduction in the consumption of energy, time and cost.

  2. Medium Density Fibreboard Made of Acetylated Sludge from Paper Mill

    Directory of Open Access Journals (Sweden)

    Luthfi Hakim


    Full Text Available Research of using sludge as raw material for making medium density fibreboard (MDF was useful to create additional value of sludge. The objective of the research was to evaluate physical properties, mechanical properties, and durability of MDF from acetylated sludge in 4 levels of acetate anhydride (0%, 3%, 5%, and 7% with 3 replicates. The MDF was made using dry process. After materials were mixed with adhesives, they were pressed using hotpress under 170 oC temperature and 45 Pa pressure for 25 minutes. The size of the MDF sample was 25 cm x 20 cm x 1 cm with 0.8 g/cm3 density. The physical properties (density, moisture content, water absorption, thickness swelling and mechanical properties (modulus of elasticity, modulus of rupture, internal bond, screw holding power was tested based on JIS A 5905-2003 standard. The durability was evaluated using SNI 01-7207-2006. All physical properties of MDF fulfill JIS A 5905-2003. Acetate anhydride decreased the moisture content value of MDF. On the other hand, all mechanical properties did not fulfill the standard. That was caused by calcium carbonate in sludge that blocked the adhesion between sludge fibres. The durability of MDF tested here was classified Class I which is very resistant to termites.


    Directory of Open Access Journals (Sweden)

    Jolanta Latosińska


    Full Text Available The study shows the results of zeolitization of municipal sewage sludge ash with the indirect fusion method followed by a hydrothermal method. The zeolitization of sewage sludge ash was conducted at the melting temperature of 550°C and the melting time of 60 minutes, crystallization temperatures of 60°C and 90°C, crystallization time of 6 hours and the SSA:NaOH ratio of 1:1.8; 1:1.4. The research of modified sewage sludge ashes included the observation of changes of ash particles surface and the identification of crystalized phases. The zeolitization of sewage sludge ash at the ratio of SSA:NaOH 1.0:1.4 did not cause the formation of zeolite phases. On the other hand, the zeolitization at the ratio of SSA:NaOH 1.0:1.8 resulted in the formation of desired zeolite phases such as zeolite Y (faujasite and hydroxysodalite. The presented method of sewage sludge ash zeolitization allows to obtain highly usable material. Synthesized zeolites may be used as adsorbents and ion exchangers. They can be potentially used to remove heavy metals as well as ammonia from water and wastewater.

  4. Anaerobic bioleaching of metals from waste activated sludge. (United States)

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E; Lens, Piet N L


    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g(-1) of copper, 487 μg g(-1) of lead, 793 μg g(-1) of zinc, 27 μg g(-1) of nickel and 2.3 μg g(-1) of cadmium. During the anaerobic acidification of 3 gdry weight L(-1) waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Environmental assessment of supercritical water oxidation of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Svanstrom, Magdalena; Froling, Morgan [Department of Chemical Engineering and Environmental Science, Chalmers University of Technology, SE-412 96 Goteborg (Sweden); Modell, Michael; Peters, William A.; Tester, Jefferson [Laboratory For Energy and the Environment (LFEE), Massachusetts Institute of Technology (MIT), Building E40, 1 Amherst Street, Cambridge, MA 02139 (United States)


    Environmental aspects of using supercritical water oxidation (SCWO) to treat sewage sludge were studied using a life cycle assessment (LCA) methodology. The system studied is the first commercial scale SCWO plant for sewage sludge in the world, treating sludge from the municipal wastewater treatment facility in Harlingen, TX, USA. The environmental impacts were evaluated using three specific environmental attributes: global warming potential (GWP), photo-oxidant creation potential (POCP) and resource depletion; as well as two single point indicators: EPS2000 and EcoIndicator99. The LCA results show that for the described process, gas-fired preheating of the sludge is the major contributor to environmental impacts, and emissions from generating electricity for pumping and for oxygen production are also important. Overall, SCWO processing of undigested sewage sludge is an environmentally attractive technology, particularly when heat is recovered from the process. Energy-conserving measures and recovery of excess oxygen from the SCWO process should be considered for improving the sustainability potential.

  6. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W


    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

  7. Metaproteomics provides functional insight into activated sludge wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Paul Wilmes


    Full Text Available Through identification of highly expressed proteins from a mixed culture activated sludge system this study provides functional evidence of microbial transformations important for enhanced biological phosphorus removal (EBPR.A laboratory-scale sequencing batch reactor was successfully operated for different levels of EBPR, removing around 25, 40 and 55 mg/l P. The microbial communities were dominated by the uncultured polyphosphate-accumulating organism "Candidatus Accumulibacter phosphatis". When EBPR failed, the sludge was dominated by tetrad-forming alpha-Proteobacteria. Representative and reproducible 2D gel protein separations were obtained for all sludge samples. 638 protein spots were matched across gels generated from the phosphate removing sludges. 111 of these were excised and 46 proteins were identified using recently available sludge metagenomic sequences. Many of these closely match proteins from "Candidatus Accumulibacter phosphatis" and could be directly linked to the EBPR process. They included enzymes involved in energy generation, polyhydroxyalkanoate synthesis, glycolysis, gluconeogenesis, glycogen synthesis, glyoxylate/TCA cycle, fatty acid beta oxidation, fatty acid synthesis and phosphate transport. Several proteins involved in cellular stress response were detected.Importantly, this study provides direct evidence linking the metabolic activities of "Accumulibacter" to the chemical transformations observed in EBPR. Finally, the results are discussed in relation to current EBPR metabolic models.

  8. Gasification of yeast industry treatment plant sludge using downdraft Gasifier. (United States)

    Ayol, Azize; Tezer, Ozgun; Gurgen, Alim


    Sludges produced in biological wastewater treatment plants have rich organic materials in their characteristics. Recent research studies have focused on the energy recovery from sludge due to its high organic content. The gasification process is a thermal conversion technology transforming the chemical energy contained in a solid fuel into thermal energy and electricity. The produced syngas as a mixture of CO, CH 4 , H 2 and other gases can be used to generate electrical energy. The gasification of yeast industry sludge has been experimentally evaluated in a pilot scale downdraft-type gasifier as a route towards the energy recovery. The gasifier has 20 kg biomass/h fuel capacity. During gasification, the temperature achieved was more than 1,000°C in the gasifier, and then the syngas was transferred to the gas engine to yield the electricity. A load was connected to the grid box and approximately 1 kWh electrical power generation for 1 kg dry sludge was determined. The characteristics of residuals - ash, glassy material - were also analyzed. It was found that most of the heavy metals were fixed in the glassy material. Experimental results showed that the yeast industry sludge was an appropriate material for gasification studies and remarkable energy recovery was obtained in terms of power production by using syngas.

  9. Effect of initial physical characteristics on sludge compost performance. (United States)

    Trémier, Anne; Teglia, Cécile; Barrington, Suzelle


    To develop an active microbial activity quickly developing stabilizing thermophilic temperatures during the composting of wastewater sludge, the bulking agent (BA) plays a major role in establishing the recipe structure, exposed particle surface area and porosity. To optimize the biodegradation of a sludge compost recipe, the objective of this paper was to study the effect and interaction of initial moisture content (MC) and BA particle size distribution. Three 300 L insulated laboratory composters were used to treat two series of ten (10) recipes with different combinations of MC and BA particle size distribution. Using a to wastewater sludge to BA dry mass ratio of 1/6, the ten (10) recipes were repeated using two BA, residues recycled from a commercial sludge composting plant and crushed wood pallets. Each four week trial monitored O(2) uptake, temperature, compost consolidation and airflow distribution. The Central Composite Factor Design method produced a model from the results estimating the impact of a wider range of MC and BA particles size distribution. The MC directly affected the total O(2) uptake and therefore, organic matter biodegradation. The BA particle size distribution influenced compost consolidation with a MC crossed effect. Both BA particle size distribution and MC influenced compost airflow dispersion. Composting was optimized using the BA consisting of recycled green waste residues with particle size of 20-30 mm and a 55% MC. The predictive models suggested the need for further optimization of sludge and wood residue composting recipe.

  10. Leachability of fired clay brick incorporating with sewage sludge waste (United States)

    Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Sarani, Noor Amira; Rahmat, Nur Aqma Izurin; Abdullah, Mohd Mustafa Al Bakri


    Sewage sludge is sewerage from wastewater treatment plants that generates millions tons of sludge ever year. Regarding this activity, it causes lack management of waste which is harmful to the surrounding conditions. Therefore, this study is focuses on the incorporation of sewage sludge waste into fired clay brick to provide an option of disposal method, producing adequate quality of brick as well as limiting the heavy metal leachability to the environment. Sewage sludge brick (SSB) mixtures were incorporated with 0%, 1%, 5%, 10%, 20% and 30% of sewage sludge waste (SSW). Heavy metals of crushed SSB were determined by using Toxicity Characteristic Leaching Procedure (TCLP) according to Method 1311 of United State Environment Protection Agency (USEPA) standard. From the results obtained, up to 20% of SSW could be incorporated into fired clay brick and comply with the USEPA standard. Therefore, this study revealed that by incorporating SSW into fired clay brick it could be an alternative method to dispose the SSW and also could act as a replacement material for brick manufacturing with appropriate mix and design.

  11. Research on Treatment Technology and Device of Oily Sludge (United States)

    Wang, J. Q.; Shui, F. S.; Li, Q. F.


    Oily sludge is a solid oily waste, which is produced during the process of oil exploitation, transportation, refining and treatment of oily sewage. It contains a great number of hazardous substance, and is difficult to handle with. To solve the problem of waste resources of oil sludge with high oil content and usually not easy to aggregate during the preparation of profile control agent, a new oily sludge treatment device was developed. This device consists of heat supply unit, flush and filter unit, oil removal unit and dehydration unit. It can effectively clean and filter out the waste from oily sludge, recycle the oil resources and reduce the water content of the residue. In the process of operation, the water and chemical agent are recycled in the device, eventually producing little sewage. The device is small, easy to move and has high degree of automation control. The experimental application shows that the oil removal rate of the oily sludge is up to 70%, and the higher the oil content rate the better the treatment.

  12. Solar-thermic sewage sludge treatment in extreme alpine environments. (United States)

    Becker, W; Schoen, M A; Wett, B


    In the framework of a program for environmental protection conducted by the German mountaineers' club (DAV) problems emerging from residual solids accumulating in on-site wastewater treatment plants of mountain refuges were investigated. To handle these problems in an ecologically and economically reasonable way two devices for solar-supported treatment of sludge and bio-solids have been developed. These units support gravity-filtration and evaporation of liquid sludge as well as thermal acceleration of composting processes. Two solar sludge dryers were installed and operated without external energy supply at alpine refuges treating primary and secondary sludge, respectively. Batch-filling during the season could increase load capacity and a total solids concentration of up to 40% could be achieved before discharge at the beginning of the next season. The promising results from the solar sludge dryer encouraged for the development of a solar composter. The period of temperature levels suitable for composting biosolids in mountain areas can be extended considerably by application of this technology--measured temperature distribution indicated no freezing at all.

  13. Characterization of water treatment sludge and its reuse as coagulant. (United States)

    Ahmad, Tarique; Ahmad, Kafeel; Ahad, Abdul; Alam, Mehtab


    Coagulation-flocculation process results in the generation of large volume of waste or residue, known as water treatment sludge (WTS), in the purification of surface water for potable supplies. Sustainable management of the inevitable waste requires careful attention from the plant operators and sludge managers. In this study, WTS produced with the optimum alum dose of 30 ml/L at the laboratory scale has been treated with sulphuric acid to bring forth a product known as sludge reagent product (SRP). The performance of SRP is evaluated for its efficiency in removing the colloidal suspensions from the Yamuna river water over wide pH range of 2-13. 1% sludge acidified with sulphuric acid of normality 2.5 at the rate of 0.05 ml/ml sludge has been observed as the optimum condition for preparing SRP from WTS. The percentage turbidity removal is greater at higher pH value and increases with increasing the dosage of SRP. The optimum SRP dosage of 8 ml/L in the pH range of 6-8 performed well in removing the colloidal suspension and other impurities from the Yamuna water. The quality of treated water met the prescribed standards for most of the quality parameters. Thus, SRP has the potential to substitute the conventional coagulants partially or completely in the water treatment process, depending on the quality needed at the users end. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. INTEC SBW Solid Sludge Surrogate Recipe and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Vince; Janikowski, Stuart; Johnson, Jim; Maio, Vince; Pao, Jenn-Hai


    A nonhazardous INTEC tank farm sludge surrogate that incorporated metathesis reactions to generate solids from solutions of known elements present in the radioactive INTEC tank farm sodium-bearing waste sludges was formulated. Elemental analyses, physical property analyses, and filtration testing were performed on waste surrogate and tank farm waste samples, and the results were compared. For testing physical systems associated with moving the tank farm solids, the surrogate described in this report is the best currently available choice. No other available surrogate exhibits the noted similarities in behavior to the sludges. The chemical morphology, particle size distribution, and settling and flow characteristics of the surrogate were similar to those exhibited by the waste sludges. Nonetheless, there is a difference in chemical makeup of the surrogate and the tank farm waste. If a chemical treatment process were to be evaluated for final treatment and disposition of the waste sludges, the surrogate synthesis process would likely require modification to yield a surrogate with a closer matching chemical composition.

  15. Comparison of different aerobic granular sludge types for activated sludge nitrification bioaugmentation potential. (United States)

    Figdore, Bryce A; Stensel, H David; Winkler, Mari-Karoliina H


    Three types of nitrifying granules were grown on media simulating anaerobic digestion dewatering reject water and compared for their potential to increase nitrification capacity when added to mainstream flocculent activated sludge treatment. An advantage of nitrification bioaugmentation with sidestream granules instead of flocculent biomass is that the granules can be selectively maintained at longer retention times than flocs and thus provide higher nitrification capacity from bioaugmentation. The three granule types and feeding conditions were: nitrifying granules with aerobic feeding, nitrifying-denitrifying granules with anoxic feeding, and nitrifying-denitrifying/phosphate-accumulating (NDN-PAO) granules with anaerobic feeding. NDN-PAO granular sludge showed the highest potential for nitrification bioaugmentation due to its better treatment performance, granule physical characteristics, and much greater production of granular mass and nitrification capacity. Dechloromonas-associated organisms were dominant in these granules; Candidatus Accumulibacter-related organisms were also present. Nitrosomonas was the dominant ammonia-oxidizing bacteria, while Candidatus Nitrotoga was an abundant nitrite-oxidizer in all granule types. Copyright © 2017. Published by Elsevier Ltd.

  16. Bioproducts for Sludge Reduction in Activated Sludge Systems Treating Oil Refinery Wastewater

    Directory of Open Access Journals (Sweden)

    Alexandre V.M.F.


    Full Text Available The use of bioproducts that change the cellular metabolism and reduce microbial growth without affecting the organic matter removal is very promising for reducing the amount of sludge in wastewater treatment systems. In this study, two bioproducts were evaluated and compared with a well-known chemical (2,4-DiNitroPhenol – DNP in activated sludge treating petroleum refinery wastewater. In batch experiments, 10 mg/L of DNP, 0.8 mg/L of a bioproduct based on Folic Acid (FA and 10 mg/L of a bioproduct based on Stress Proteins (SP led to 30.6%, 43.2% and 29.8% lower disposal of total solids, respectively. Operating on a continuous regimen, the addition of 10 mg/L of the bioproduct based on SP led to 45.7% lower disposal for 50 days. In all cases, no loss of efficiency in the Chemical Oxygen Demand (COD removal was observed.

  17. Characterization of the retained sludge in a down-flow hanging sponge (DHS) reactor with emphasis on its low excess sludge production. (United States)

    Onodera, Takashi; Matsunaga, Kengo; Kubota, Kengo; Taniguchi, Ryoko; Harada, Hideki; Syutsubo, Kazuaki; Okubo, Tsutomu; Uemura, Shigeki; Araki, Nobuo; Yamada, Masayoshi; Yamauchi, Masahito; Yamaguchi, Takashi


    Experiments to characterize retained sludge in a down-flow hanging sponge (DHS) reactor fed with upflow anaerobic sludge blanket (UASB) treated sewage under moderate conditions were conducted. Plenty of oxygen was supplied through the DHS reactor without aeration and the effluent qualities after the reactor were comparable to activated sludge processes. The average excess sludge production rate was 0.09 g SS g(-1) COD removed. The DHS reactor maintained a high sludge concentration of 26.9 g VSS L(-1) sponge, resulting in a low loading rate of 0.032 g COD g(-1) VSS day(-1). The endogenous respiration rate of DHS sludge was comparable to previously reported aerobic sludges. The numbers of microfauna were one order of magnitude greater than those in activated sludge. The results indicated that low excess sludge production was attributable to the high sludge concentration, sufficient oxygen supply, adequate endogenous respiration rate, and a high density and diversity of microfauna. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  18. Improving Settling Dynamics of Activated Sludge by Adding Fine Talc Powder

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben; Clauss, F.


    The effect of adding varying mixtures of talc and chlorite powder to activated sludge in order to improve the settling characteristic has been studied. The powder is found to improve the settling velocity of the sludge, strictly by increasing the average density of the sludge floc aggregate. The ...

  19. Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions

    NARCIS (Netherlands)

    Seghezzo, L.; Cuevas, C.M.; Trupiano, A.P.; Guerra, R.G.; Gonzalez, S.M.; Zeeman, G.; Lettinga, G.


    The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical

  20. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    NARCIS (Netherlands)

    Tervahauta, T.H.; Bryant, I.M.; Hernandez Leal, L.; Buisman, C.J.N.; Zeeman, G.


    This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB) reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were

  1. Land application of sewage sludge: A soil columns study | Gascó ...

    African Journals Online (AJOL)

    Land application of sewage sludge: A soil columns study. G Gascó, MC Lobo, F Guerrero. Abstract. A column study was conducted to assess the potential Cr, Ni, Cu, Zn, Cd and Pb movement through a reconstructed soil profile to which surface composted sewage sludge was applied. Sewage sludge was mixed into the top ...

  2. Metal uptake by plants from sludge-amended soils: caution is required in the plateau interpretation

    DEFF Research Database (Denmark)

    Hamon, R.E.; Holm, Peter Engelund; Lorenz, S.E.


    by increased sorption sites provided by the sludge constituents at the high sludge loading rates. We grew Raphanus sativus L. in a soil historically amended with sewage sludge at different rates and examined concentrations of Cd and Zn in the plants and in corresponding rhizosphere soil solution. Metal...

  3. Laboratory development of sludge washing and alkaline leaching processes: Test plan for FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rapko, B.M.; Lumetta, G.J.


    The US Department of Energy plans to vitrify (as borosilicate glass) the large volumes of high-level radioactive wastes at the Hanford site. To reduce costs, pretreatment processes will be used to reduce the volume of borosilicate glass required for disposal. Several options are being considered for the pretreatment processes: (1) sludge washing with water or dilute hydroxide: designed to remove most of the Na from the sludge, thus significantly reducing the volume of waste to be vitrified; (2) sludge washing plus caustic leaching and/or metathesis (alkaline sludge leaching): designed to dissolve large quantities of certain nonradioactive elements, such as Al, Cr and P, thus reducing the volume of waste even more; (3) sludge washing, sludge dissolution, and separation of radionuclides from the dissolved sludge solutions (advanced processing): designed to remove all radionuclides for concentration into a minimum waste volume. This report describes a test plan for work that will be performed in FY 1994 under the Sludge Washing and Caustic Leaching Studies Task (WBS 0402) of the Tank Waste Remediation System (TWRS) Pretreatment Project. The objectives of the work described here are to determine the effects of sludge washing and alkaline leaching on sludge composition and the physical properties of the washed sludge and to evaluate alkaline leaching methods for their impact on the volume of borosilicate glass required to dispose of certain Hanford tank sludges.

  4. Wastewater treatment sludge as a raw material for the production of Bacillus thuringiensis based biopesticides. (United States)

    Montiel, M D; Tyagi, R D; Valero, J R


    Seven wastewater sludges of different origins and types were used as an alternate culture medium for producing Bacillus thuringiensis variety kurstaki HD-1. The sludge samples were used under three different preparations: without pre-treatment, with acid treatment (hydrolysed sludge) and the supernatant obtained after centrifugation of the hydrolysed sludge. The sludge composition varied widely with origin and the type of sludge. Growth and sporulation were evaluated by the total viable cell count and spore count of the preparations. Growth, sporulation and endotoxin production were affected by the sludge origin. Hydrolysed sludge gave the highest viable cell and spore counts while the liquid phase (supernatant) gave the lowest. Non-hydrolysed primary sludge from Valcartier was unable to sustain bacterial growth because of its low pH. Bioassays were conducted against larvae of spruce budworm to evaluate entomotoxic potential of the preparations obtained. In general, sludge hydrolysis increased the entomotoxicity yields. Similar entomotoxicity was observed in Black Lake secondary sludge (4100 IU/microL) as that obtained in the reference soya medium (3800 IU/microL). The use of the sludge supernatant (liquid phase) was not recommended due to the low entomotoxic potential obtained.

  5. Concentrations, Distribution and Persistence of Fluorotelomer Alcohols in Sludge-Applied Soils near Decatur, Alabama, USA (United States)

    Soil samples were collected for fluorotelomer alcohol (FTOH) analyses from six fields to which sludge had been applied and one “background” field that had not received sludge. Ten analytes in soil extracts were quantified using GC/MS. Sludge-applied fields had surface soil FTOH c...

  6. Analysis of sludge from K East basin floor and weasel pit

    Energy Technology Data Exchange (ETDEWEB)

    Makenas, B.J., Westinghouse Hanford


    Sludge samples from the floor of the Hanford K East Basin fuel storage pool have been retrieved and analyzed. Both chemical and physical properties have been determined. The results are to be used to determine the disposition of the bulk of the sludge and possibly assess the impact of residual sludge on dry storage of the associated intact metallic uranium fuel elements.

  7. Zinc uptake by vegetables: Effects of soil type and sewage sludge

    African Journals Online (AJOL)



    Nov 16, 2009 ... Studies were carried out to investigate how sludge applied to 3 soil types to improve the yield of carrots. (Daucus carota) and ... Sludge application also increased the fresh weight of spinach by up to 31% and carrots by up to 10%, these ... Sludge composition varies from one wastewater treatment plant to ...

  8. Anaerobic stabilisation of sludge produced during municipal wastewater treatment by electrocoagulation. (United States)

    Hutnan, M; Drtil, M; Kalina, A


    Anaerobic digestion of sludge from small electrocoagulation wastewater treatment plant (SEWWTP) is described. The sludge for digestion (SEWWTP sludge) was taken from pilot-scale SEWWTP with the capacity of about 200-population equivalent (25 m3 of municipal wastewater per day). Due to the technology of wastewater treatment, the characteristics of SEWWTP sludge was different from sludge produced in conventional mechanical-biological wastewater treatment plant. Therefore, experiments were focused on possibilities of anaerobic sludge digestion and determination of conditions and parameters (amount and quality of the sludge, biogas production, etc.). Average COD removal efficiency in the pilot-scale SEWWTP exceeded 80%. Organic content of excess sludge (volatile suspended solids (VSS)) was in the range of 52.1-59.2% (these values are much lower compared to VSS content in raw sludge from conventional municipal wastewater treatment plant, where VSS is about 75%). Biogas production from anaerobic digestion of SEWWTP sludge was approximately three times lower compared to standard production in conventional municipal wastewater treatment plant. Low pH (6.5-6.7), high concentration of iron (up to 1400 mg/L) and aluminium (up to 1300 mg/L) and very low (almost zero) concentration of dissolved phosphorus in sludge water were the main factors limiting the rate of anaerobic processes. Based on these results, anaerobic digestion of SEWWTP sludge was not recommended as an appropriate stabilisation method.

  9. Study of heavy metal in sewage sludge and in Chinese cabbage ...

    African Journals Online (AJOL)

    The study was performed to investigate the heavy metal content and availability for crops in sewage sludge and its accumulation in Chinese cabbage grown in sewage sludge amended soil. We determined the total and chemical fraction of As, Cr, Cd, Pb, Ni, Cu, Zn, Fe, Mg and Mn in sewage sludge and the total content of ...

  10. Heavy metals removal from sewage sludge : Is practical application a feasible option?

    NARCIS (Netherlands)

    Marchioretto, M.M.; Rulkens, W.H.; Bruning, H.


    The present work evaluates some new developments concerning research into the removal of heavy metals from sewage sludge and discusses the significance for practical application. As such, the complete process of sludge treatment as an integral part of a sludge management process is considered. Two

  11. Monometal and competitive adsorption of heavy metals by sewage sludge-amended soils (United States)

    Sewage sludge-amended soils may alter their ability to adsorb heavy metals over time, due to the decomposition of sludge-borne organic matter. Thus, we studied Cd, Ni, and Zn adsorption by a sewage sludge-amended soil (Typic Xerofluvent) before and after one-year incubation in both monometal and com...

  12. Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Samolada, M.C. [Dept. Secretariat of Environmental and Urban Planning – Decentralized Area Macedonian Thrace, Taki Oikonomidi 1, 54008 Thessaloniki (Greece); Zabaniotou, A.A., E-mail: [Aristotle University of Thessaloniki, Dept. of Chemical Engineering, University Box 455, University Campus, 541 24 Thessaloniki (Greece)


    Highlights: • The high output of MSS highlights the need for alternative routes of valorization. • Evaluation of 3 sludge-to-energy valorisation methods through SWOT analysis. • Pyrolysis is an energy and material recovery process resulting to ‘zero waste’. • Identification of challenges and barriers for MSS pyrolysis in Greece was investigated. • Adopters of pyrolysis systems face the challenge of finding new product markets. - Abstract: For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a ‘zero waste’ solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated.

  13. Sludge Washing And Demonstration Of The DWPF Flowsheet In The SRNL Shielded Cells For Sludge Batch 8 Qualification

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J. M.; Crawford, C. L.


    The current Waste Solidification Engineering (WSE) practice is to prepare sludge batches in Tank 51 by transferring sludge from other tanks to Tank 51. Tank 51 sludge is washed and transferred to Tank 40, the current Defense Waste Processing Facility (DWPF) feed tank. Prior to transfer of Tank 51 to Tank 40, the Savannah River National Laboratory (SRNL) typically simulates the Tank Farm and DWPF processes using a Tank 51 sample (referred to as the qualification sample). WSE requested the SRNL to perform characterization on a Sludge Batch 8 (SB8) sample and demonstrate the DWPF flowsheet in the SRNL shielded cells for SB8 as the final qualification process required prior to SB8 transfer from Tank 51 to Tank 40. A 3-L sample from Tank 51 (the SB8 qualification sample; Tank Farm sample HTF-51-12-80) was received by SRNL on September 20, 2012. The as-received sample was characterized prior to being washed. The washed material was further characterized and used as the material for the DWPF process simulation including a Sludge Receipt and Adjustment Tank (SRAT) cycle, a Slurry Mix Evaporator (SME) cycle, and glass fabrication and chemical durability measurements.

  14. Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor. (United States)

    Ge, Huoqing; Batstone, Damien; Keller, Jurg


    The need to reduce energy input and enhance energy recovery from wastewater is driving renewed interest in high-rate activated sludge treatment (i.e. short hydraulic and solids retention times (HRT and SRT, respectively)). This process generates short SRT activated sludge stream, which should be highly degradable. However, the evaluation of anaerobic digestion of short SRT sludge has been limited. This paper assesses anaerobic digestion of short SRT sludge digestion derived from meat processing wastewater under thermophilic and mesophilic conditions. The thermophilic digestion system (55°C) achieved 60 and 68% volatile solids destruction at 8 day and 10 day HRT, respectively, compared with 50% in the mesophilic digestion system (35°C, 10 day HRT). The digestion effluents from the thermophilic (8-10 day HRT) and mesophilic systems were stable, as assessed by residual methane potentials. The ammonia rich sludge dewatering liquor was effectively treated by a batch anammox process, which exhibited comparable nitrogen removal rate as the tests using a control synthetic ammonia solution, indicating that the dewatering liquor did not have inhibiting/toxic effects on the anammox activity.

  15. Physicochemical changes effected in activated sludge by the earthworm Eisenia foetida. [Concentration of heavy metals during sludge catabolism

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, R. (State Univ. of New York, Syracuse); Hartenstein, F.


    Measurements were made of some physicochemical changes effected in activated sludge by the earthworm Eisenia foetida following conversion of the sludge into wormcasts. Mineralization was accelerated 1.3-fold and 2% of the minerals were assimilated. The rate at which heavy metals were concentrated during sludge catabolism was also accelerated. Castings stabilized within 2 weeks, as indexed by respirometry. Nucleic acids, which can be used as an index of microbial biomass, were present at a greater concentration in the wormcasts than in the sludge, while the phenolic content, which may potentially serve as an index of humification, was less concentrated. Other changes included a reduction in pH and an increase in oxidation-reduction potential and cation exchange capacity. The major general effect of E. foetida on the physicochemical properties of activated sludge is to convert a material which has a relatively small surface/volume ratio into numerous particles with an overall large S/V ratio, thus accelerating decomposition, mineralization, drying, and preclusion of malodor.

  16. ABB Combustion Engineering approach to steam generator sludge lancing

    Energy Technology Data Exchange (ETDEWEB)

    Estes, G.T. [ABB CE, Chattanooga, TN (United States)


    During the normal operation of a recirculating steam generator, insoluble corrosion products, commonly called {open_quotes}sludge,{close_quotes} are formed. Sludge accumulates on the tube sheet, heat transfer tubes, support plates, and other surfaces. It can be expected that corrosion products will continue to build up even with rigid secondary water chemistry controls. This corrosion product buildup directly affects thermal efficiency, resulting in megawatt and pressure loss. Secondary-side corrosion causes an increase in tubes that require plugging or sleeving. More importantly, corrosion product buildup has caused forced outages and steam-generator replacements. One plant has permanently shut down due to steam-generator secondary-side corrosion. This report describes a process for sludge removal.

  17. Aerobic storage under dynamic conditions in activated sludge processes

    DEFF Research Database (Denmark)

    Majone, M.; Dircks, K.


    In activated sludge processes, several plant configurations (like plug-flow configuration of the aeration tanks, systems with selectors, contact-stabilization processes or SBR processes) impose a concentration gradient of the carbon sources to the biomass. As a consequence, the biomass grows under...... mechanisms can also contribute to substrate removal, depending on the microbial composition and the previous "history" of the biomass. In this paper the type and the extent of this dynamic response is discussed by review of experimental studies on pure cultures, mixed cultures and activated sludges...... and with main reference to its relevance on population dynamics in the activated sludge. Possible conceptual approaches to storage modelling are also presented, including both structured and unstructured modelling. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....


    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Le-Quy, Vang; Nielsen, Kåre Lehmann

    and when external carbon sources were supplemented to the activated sludge the composition of the denitrifying communities was significantly affected. Transcriptome profiling provided detailed insight in the metabolic pathways in several of the active denitrifiers in activated sludge. In conclusion...... reactor studies. To obtain better identification of active denitrifying communities in full-scale wastewater treatment plants (WWTPs) we applied DNA-SIP with 13C-labelled substrates, and RT-PCR of expressed denitrification genes (nirS, nirK and nosZ) upon various substrate-inductions. To come around...... were determined with quantitative FISH, while their active metabolic pathways were investigated directly in activated sludge with a tag-based metatranscriptomic approach under acetate-utilizing and denitrifying conditions. The different methods revealed a majority of denitrifiers in all WWTPs belonging...

  19. The final treatment of FGD-waste water sludge

    Energy Technology Data Exchange (ETDEWEB)

    Brugghen, F.W. van der (N.V. KEMA, Arnhem (Netherlands))


    FGD installations based on lime/limestone gypsum processes produce waste water. This waste water has to be treated prior to discharge. The sludge formed during this waste water treatment contains gypsum, CaF[sub 2], Al[sub 2]O[sub 3], SiO[sub 2], Fe[sub 2]O[sub 3] and MgO as well as minor amounts of heavy metals like As, Cd, Pb, Zn and Hg. There are three methods for the final treatment of the sludges: disposal; mixing with gypsum; coffering in the boiler. An inventory has been made of the amounts and composition of the sludge produced by FGD plants in The Netherlands. The consequences of the three treatment methods for emissions, by-product quality and costs are described and compared. 1 ref., 2 figs., 7 tabs.

  20. Technical, economic and environmental assessment of sludge treatment wetlands. (United States)

    Uggetti, Enrica; Ferrer, Ivet; Molist, Jordi; García, Joan


    Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Life cycle assessment of sewage sludge management: A review

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Christensen, Thomas Højlund; Scheutz, Charlotte


    In this article, 35 published studies on life cycle assessment (LCA) of sewage sludge were reviewed for their methodological and technological assumptions. Overall, LCA has been providing a flexible framework to quantify environmental impacts of wastewater and sewage sludge treatment and disposal...... by the methodological development of the life cycle impact assessment (LCIA) and the advancement of research in quantifying environmental emissions associated with wastewater and sewage sludge treatment processes. Thus, large discrepancies were found in the selection of the environmental emissions to be included...... processes for multiple scales, ranging from process selection to policy evaluation. The results of LCA are, in principle, unique to the goal and scope of each study, reflecting its local conditions and comparison between different LCAs is not intended. Furthermore, the assessments are limited...

  2. Analysis of sludge aggregates produced during electrocoagulation of model wastewater. (United States)

    Załęska-Chróst, B; Wardzyńska, R


    This paper presents the results of the study of sludge aggregates produced during electrocoagulation of model wastewater of a composition corresponding to the effluents from the cellulose and paper industry. Wastewater was electrocoagulated statically using aluminium electrodes with a current density of 31.25 A m(-2) and 62.50 A m(-2). In subsequent stages of the treatment, sludge flocs were collected, their size was studied and their floc settling velocity (30-520 μm s(-1)) and fractal dimension (D) were determined. The values of D ranged from 1.53 to 1.95 and were directly proportional to the degree of wastewater treatment. Higher values of D were determined for sludge with lower water content (after 24 hours' settling). Fractal dimension can therefore be used as an additional parameter of wastewater treatment control.

  3. Hanford Sludge Simulant Selection for Soil Mechanics Property Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Beric E.; Russell, Renee L.; Mahoney, Lenna A.; Brown, Garrett N.; Rinehart, Donald E.; Buchmiller, William C.; Golovich, Elizabeth C.; Crum, Jarrod V.


    The current System Plan for the Hanford Tank Farms uses relaxed buoyant displacement gas release event (BDGRE) controls for deep sludge (i.e., high level waste [HLW]) tanks, which allows the tank farms to use more storage space, i.e., increase the sediment depth, in some of the double-shell tanks (DSTs). The relaxed BDGRE controls are based on preliminary analysis of a gas release model from van Kessel and van Kesteren. Application of the van Kessel and van Kesteren model requires parametric information for the sediment, including the lateral earth pressure at rest and shear modulus. No lateral earth pressure at rest and shear modulus in situ measurements for Hanford sludge are currently available. The two chemical sludge simulants will be used in follow-on work to experimentally measure the van Kessel and van Kesteren model parameters, lateral earth pressure at rest, and shear modulus.

  4. Adsorption mechanisms and the effect of oxytetracycline on activated sludge. (United States)

    Song, Xiancai; Liu, Dongfang; Zhang, Guowei; Frigon, Matthew; Meng, Xianrong; Li, Kexun


    The adsorption mechanisms and the effect of Oxytetracycline (OTC) onto activated sludge were studied. The results show that the adsorption of Oxytetracycline (OTC) onto activated sludge was coincident with the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model had the best fit which suggested that chemical adsorption mechanism was dominant. The influences including pH and metal ions on the OTC were examined. It was demonstrated that the adsorption process was highly pH-dependant, which indicate that cationic exchange mechanisms may play an important role in the adsorption process. Na(+), K(+), Ca(2+), Mg(2+) and Cd(2+) ions more or less inhibited the adsorption of OTC on activated sludge while Cu(2+) enhanced the adsorption ability. The phenomenon may reflect the result that a surface complexation mechanism could involved in the adsorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.


    This report summarizes information and data on the reaction behavior of uranium metal in water, in water-saturated simulated and genuine K Basin sludge, and in grout matrices. This information and data are used to establish the technical basis for metallic uranium reaction behavior for the K Basin Sludge Treatment Project (STP). The specific objective of this report is to consolidate the various sources of information into a concise document to serve as a high-level reference and road map for customers, regulators, and interested parties outside the STP (e.g., external reviewers, other DOE sites) to clearly understand the current basis for the corrosion of uranium metal in water, sludge, and grout.

  6. Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.


    This report summarizes information and data on the reaction behavior of uranium metal in water, in water-saturated simulated and genuine K Basin sludge, and in grout matrices. This information and data are used to establish the technical basis for metallic uranium reaction behavior for the K Basin Sludge Treatment Project (STP). The specific objective of this report is to consolidate the various sources of information into a concise document to serve as a high-level reference and road map for customers, regulators, and interested parties outside the STP (e.g., external reviewers, other DOE sites) to clearly understand the current basis for the corrosion of uranium metal in water, sludge, and grout.

  7. Improving the sludge conditioning potential of moringa seed (United States)

    Ademiluyi, Joel O.; Eze, Romanus M.


    In the search for a cheaper material to effectively condition sludge, oil-free moringa seed was prepared and tested. A Soxhlet apparatus was used to extract the oil from moringa seed ( Moringa oleifera). The oil-free seed (marc) has been found to have higher conditioning potential than the ordinary moringa seed. However, the traditional ferric chloride is still a better sludge conditioner than moringa seed marc. For the digested domestic sludge used, optimum conditioning dosages were found to be 0.6, 0.80, and 1.10% of the total solids for ferric chloride, marc of the moringa seed, and ordinary moringa seed, respectively. Since little or no operational material is lost in the extraction process, the moringa seed marc is a promising conditioner in place of the ordinary seed.

  8. Phosphorus recovery from sewage sludge by an electrokinetic process

    DEFF Research Database (Denmark)

    Ribeiro, A.B.; Couto, N.; Mateus, E.P.

    As population keeps growing, it becomes important to guarantee the supply of staple foods, being necessary to assure good level of nutrients in the soil. Phosphorus (P) is a macronutrient indispensable for plants growth and a non-renewable resource, as phosphorites are estimated to be able...... to supply P for the next ca. 80 years. Additionaly, the quality of this raw material has deteriorated due to contamination, which has increased processing costs of mineral P fertilizers. The recovery of nutrients, like P, from secondary resources urges. Sewage sludge (SS) and sewage sludge ash (SSA) from...... be an effective technique for removing contaminants and recover P from SS and/or SSA. The application of a low-level direct current onto the sludge segment results in both electro-osmotic and electro-migration flows, which are able to induce the migration of ions. For this reason it is expected that phosphate...

  9. Useful Ingredients Recovery from Sewage Sludge by using Hydrothermal Reaction (United States)

    Suzuki, Koichi; Moriyama, Mika; Yamasaki, Yuki; Takahashi, Yui; Inoue, Chihiro


    Hydrothermal treatment of sludge from a sewage treatment plant was conducted to obtain useful ingredients for culture of specific microbes which can reduce polysulfide ion into sulfide ion and/or hydrogen sulfide. Several additives such as acid, base, and oxidizer were added to the hydrothermal reaction of excess sludge to promote the production of useful materials. After hydrothermal treatment, reaction solution and precipitation were qualitatively and quantitatively analyzed and estimated the availability as nutrition in cultural medium. From the results of product analysis, most of organic solid in sewage was basically decomposed by hydrothermal hydrolysis and transformed into oily or water-soluble compounds. Bacterial culture of sulfate-reducing bacteria (SRB) showed the good results in multiplication with medium which was obtained from hydrothermal treatment of sewage sludge with magnesium or calcium hydroxide and hydrogen peroxide.

  10. The sustainable utilization of malting industry wastewater biological treatment sludge (United States)

    Vasilenko, T. A.; Svintsov, A. V.; Chernysh, I. V.


    The article deals with the research of using the sludge from malting industry wastewater’s biological treatment and the calcium carbonate slurry as organo-mineral fertilizing additives. The sludge, generated as a result of industrial wastewater biological treatment, is subject to dumping at solid domestic waste landfills, which has a negative impact on the environment, though its properties and composition allow using it as an organic fertilizer. The physical and chemical properties of both wastes have been studied; the recommendations concerning the optimum composition of soil mix, containing the above-mentioned components, have been provided. The phytotoxic effect on the germination capacity and sprouts of cress (Lepidium sativum), barley (Hordéum vulgáre) and oats (Avena sativa) in soil mixes has been determined. The heavy metals and arsenic contents in the sludge does not exceed the allowable level; it is also free of pathogenic flora and helminthes.

  11. Physicochemical characteristics of anaerobic H2-producing granular sludge. (United States)

    Li, Wen-Wei; Yu, Han-Qing


    Granule-based biological H2 production processes are gaining great popularity in recent years. An efficient and stable operating of such systems relies heavily on the performance of the H2-producing granules (HPGs), which possess many unique properties compared with floc sludge and methanogenic granules. Hence, a full understanding of the sludge characteristics is essential. Especially, the physicochemical properties of HPGs may provide useful information for effective evaluation of system status. This review offers a systematical introduction of the physicochemical properties of HPGs, including size, morphology, settling velocity, permeability, rheology, surface charge, hydrophobicity and extracellular polymeric substances (EPS). We also analyze the relationships between these physicochemical factors and the system performance, and discuss the remaining challenges and future implications for sludge characterization and process monitoring. This work may facilitate a better understanding of granule-based biological H2 production processes and offer a basis for timely process monitoring and manipulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Toxicities of triclosan, phenol, and copper sulfate in activated sludge. (United States)

    Neumegen, Rosalind A; Fernández-Alba, Amadeo R; Chisti, Yusuf


    The effect of toxicants on the BOD degradation rate constant was used to quantitatively establish the toxicity of triclosan, phenol, and copper (II) against activated sludge microorganisms. Toxicities were tested over the following ranges of concentrations: 0-450 mg/L for phenol, 0-2 mg/L for triclosan, and 0-35 mg/L for copper sulfate (pentahydrate). According to the EC(50) values, triclosan was the most toxic compound tested (EC(50) = 1.82 +/- 0.1 mg/L), copper (II) had intermediate toxicity (EC(50) = 18.3 +/- 0.37 mg/L), and phenol was the least toxic (EC(50) = 270 +/- 0.26 mg/L). The presence of 0.2% DMSO had no toxic effect on the activated sludge. The toxicity evaluation method used was simple, reproducible, and directly relevant to activated sludge wastewater treatment processes.

  13. Anaerobic co-digestion of sewage sludge and food waste. (United States)

    Prabhu, Meghanath S; Mutnuri, Srikanth


    Anaerobic co-digestion of organic matter improves digester operating characteristics and its performance. In the present work, food waste was collected from the institute cafeteria. Two types of sludge (before centrifuge and after centrifuge) were collected from the fluidised bed reactor of the institute treating sewage wastewater. Food waste and sludge were studied for their physico-chemical characteristics, such as pH, chemical oxygen demand, total solids, volatile solids, ammoniacal nitrogen, and total nitrogen. A biomethane potential assay was carried out to find out the optimum mixing ratio of food waste and sludge for anaerobic co-digestion. Results indicated that food waste mixed with sludge in the ratio of 1:2 produced the maximum biogas of 823 ml gVS(-1)(21 days) with an average methane content of 60%. Batch studies were conducted in 5 L lab-glass reactors at a mesophilic temperature. The effect of different substrate loading rates on biogas production was investigated. The mixing ratio of food waste and sludge was 1:2. A loading rate of 1 gVS L d(-1)gave the maximum biogas production of 742 ml g(-1)VS L d(-1)with a methane content of 50%, followed by 2 gVS L d(-1)with biogas of 539 ml g(-1)VS L d(-1) Microbial diversity of the reactor during fed batch studies was investigated by terminal restriction fragment length polymorphism. A pilot-scale co-digestion of food waste and sludge (before centrifuge) indicated the process stability of anaerobic digestion. © The Author(s) 2016.

  14. Biosynthesised magnetic iron nanoparticles for sludge dewatering via Fenton process. (United States)

    Ealias, Anu Mary; Jose, Jephin Varughese; Saravanakumar, M P


    The magnetic iron nanoparticles (MFeNp) were biosynthesised using the extract of Cinnamomum tamala (bay leaf) and examined for its efficacy on sludge dewatering. The characteristics of MFeNp were studied using scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectrometer (XPS) techniques. The presence of polyphenolic compounds were confirmed by FTIR and XPS analysis. The reduction in capillary suction time (CST) (71.36 to 16.5 s) and specific resistance to filtration (SRF) (53.71 × 10(11) to 1.47 × 10(11) m/kg) values have indicated that the use of Fenton nanocatalyst enhanced the sludge dewaterability. The differential scanning calorimetry (DSC) analysis has shown that the mass of bound water in the treated sludge was decreased significantly from 1.45 to 0.92 kg H2O/kg DS. The breakdown of extracellular polymeric substances (EPS) by the MFeNp leads to the significant reduction in proteins, polysaccharides, water content and heavy metals. The optimisation using response surface modelling (RSM) have shown that the maximum removal efficiency of water from the sludge was 85.9 % when the optimum pH (3) MFeNp dosage (50 mg/g DS) and H2O2 dosage (500 mg/g DS) were maintained. The experimental results and the statistical optimisation have suggested that MFeNp can be used as a potential nanocatalyst for the sludge dewaterability and hence it can be used for the agricultural purpose. Graphical abstract Schematic representation of sludge dewatering process.

  15. Aged refuse enhances anaerobic digestion of waste activated sludge. (United States)

    Zhao, Jianwei; Gui, Lin; Wang, Qilin; Liu, Yiwen; Wang, Dongbo; Ni, Bing-Jie; Li, Xiaoming; Xu, Rui; Zeng, Guangming; Yang, Qi


    In this work, a low-cost alternative approach (i.e., adding aged refuse (AR) into waste activated sludge) to significantly enhance anaerobic digestion of sludge was reported. Experimental results showed that with the addition dosage of AR increasing from 0 to 400 mg/g dry sludge soluble chemical oxygen demand (COD) increased from 1150 to 5240 mg/L at the digestion time of 5 d, while the maximal production of volatile fatty acids (VFA) increased from 82.6 to 183.9 mg COD/g volatile suspended solids. Although further increase of AR addition decreased the concentrations of both soluble COD and VFA, their contents in these systems with AR addition at any concentration investigated were still higher than those in the blank, which resulted in higher methane yields in these systems. Mechanism studies revealed that pertinent addition of AR promoted solubilization, hydrolysis, and acidogenesis processes and did not affect methanogenesis significantly. It was found that varieties of enzymes and anaerobes in AR were primary reason for the enhancement of anaerobic digestion. Humic substances in AR benefited hydrolysis and acidogenesis but inhibited methanogenesis. The effect of heavy metals in AR on sludge anaerobic digestion was dosage dependent. Sludge anaerobic digestion was enhanced by appropriate amounts of heavy metals but inhibited by excessive amounts of heavy metals. The relative abundances of microorganisms responsible for sludge hydrolysis and acidogenesis were also observed to be improved in the system with AR addition, which was consistent with the performance of anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Determination and characterization of pharmaceuticals in sludge from municipal and livestock wastewater treatment plants. (United States)

    Ekpeghere, Kalu Ibe; Lee, Ji-Woo; Kim, Hee-Young; Shin, Sun-Kyoung; Oh, Jeong-Eun


    This study investigated 24 pharmaceuticals compounds belonging to the classes of analgesics, stimulants, anti-seizures, non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics in the sludge of 12 municipal sewage treatment plants (S-sludge) and 4 livestock wastewater treatment plants (L-sludge) located across Korea. Over 70% of the target compounds were detected in at least one sample of S-sludge and L-sludge. The total concentration of the target pharmaceutical compounds detected in S-sludge was 2.622-422.8 mg kg(-1)and the most dominant compound was acetylsalicylic acid (ASA: 0.374-367.0 mg kg(-1)) whereas in L-sludge, the total concentration was 43.87-156.8 mg kg(-1)and the most abundant compound was oxytetracycline (OTC: 34.54-86.39 mg kg(-1)). Cluster analysis revealed two distinct groups: group A, which were S-sludge samples including ASA, carbamazepine (CBM), and others, and group B were L-sludge samples, dominated by antibiotics (CTC, OTC, LIN). The total daily load amount of the target pharmaceuticals in S-sludge was 0.010-268.9 kg day(-1) while the L-sludge was 0.021-0.529 kg day(-1). The estimated amounts of the target pharmaceutical discharged from S-sludge and L-sludge into the Korean environment were 150.2 ± 47.94 ton yr(-1) and 15.05 ± 5.671 ton yr(-1) respectively, but the discharged amount of antibiotics from S-sludge (6.945 ton yr(-1)) was lower than that from L-sludge (9.234 ton yr(-1)). Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant. (United States)

    Tamis, J; van Schouwenburg, G; Kleerebezem, R; van Loosdrecht, M C M


    Sludge predation can be an effective solution to reduce sludge production at a wastewater treatment plant. Oligochaete worms are the natural consumers of biomass in benthic layers in ecosystems. In this study the results of secondary sludge degradation by the aquatic Oligochaete worm Aulophorus furcatus in a 125 m(3) reactor and further sludge conversion in an anaerobic tank are presented. The system was operated over a period of 4 years at WWTP Wolvega, the Netherlands and was fed with secondary sludge from a low loaded activated sludge process. It was possible to maintain a stable and active population of the aquatic worm species A. furcatus during the full period. Under optimal conditions a sludge conversion of 150-200 kg TSS/d or 1.2-1.6 kg TSS/m(3)/d was established in the worm reactor. The worms grew as a biofilm on carrier material in the reactor. The surface specific conversion rate reached 140-180 g TSS/m(2)d and the worm biomass specific conversion rate was 0.5-1 g TSS sludge/g dry weight worms per day. The sludge reduction under optimal conditions in the worm reactor was 30-40%. The degradation by worms was an order of magnitude larger than the endogenous conversion rate of the secondary sludge. Effluent sludge from the worm reactor was stored in an anaerobic tank where methanogenic processes became apparent. It appeared that besides reducing the sludge amount, the worms' activity increased anaerobic digestibility, allowing for future optimisation of the total system by maximising sludge reduction and methane formation. In the whole system it was possible to reduce the amount of sludge by at least 65% on TSS basis. This is a much better total conversion than reported for anaerobic biodegradability of secondary sludge of 20-30% efficiency in terms of TSS reduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. A Guide for Developing Standard Operating Job Procedures for the Sludge Conditioning & Dewatering Process Wastewater Treatment Facility. SOJP No. 11. (United States)

    Schwing, Carl M.

    This guide describes standard operating job procedures for the sludge conditioning and dewatering process of wastewater treatment facilities. In this process, sludge is treated with chemicals to make the sludge coagulate and give up its water more easily. The treated sludge is then dewatered using a vacuum filter. The guide gives step-by-step…

  19. Effect of sludges on bacteria in agricultural soil

    DEFF Research Database (Denmark)

    Kuntz, Jérôme; Nassr-Amellal, Najat; Lollier, Marc


    (TTGE). At the laboratory scale, DS and especially LRS modified the composition of the bacterial communities (irrespective of the addition of BaPYR, DBP or NP or not). Sludges, especially LRS, very probably acted both as a bacterial inoculum and a nutrient source. The combined effect was transient...... in the laboratory conditions probably due to the favorable conditions of mineralization. The results observed with soil amended with the same sludges and cultivated or not with carrots in outdoor lysimeters were similar to those observed in the laboratory experiments. Thus, this bioassay allowed predicting...

  20. Reuse of residual sludge from stone-processing: differences and similarities between sludge coming from carbonate and silicate stones (United States)

    Careddu, Nicola; Antonella Dino, Giovanna


    Residual sludge coming from dimension stone working activities represents a serious environmental and economic problem both for Stone Industry and citizens. Indeed, most of time, residual sludge is landfilled because of the difficulties to recover it; such difficulties are mainly connected to local legislation and a lack of proper protocols. In general, it is possible to individuate two different categories of sludge: residual sludge coming from carbonate rocks (CS) and those coming from silicate rocks (SS). Both of them are characterised by a very fine size distribution. CS is composed mainly by the same compounds of the processed stones (marble, limestone, travertine). The reason of this is related to the very slow wear of diamond tools during processing which entails a negligible content of heavy metals. CS becomes very interesting, from an economic point of view, when it has a CaCO3 grade > 95 %. On the contrary, SS is characterised by high heavy metal and TPH content. Residual sludge from the processing of silicate rocks can be split in three different sub-categories, depending on the way they are produced, and in particular: sludge from gangsaw using abrasive steel shot (GSS), sludge from multi diamond-saw block cutter (DBC), and mixed sludge (MS) from gangsaw and block cutter. These three sub-categories show different problems connected to heavy metal content, indeed on the one hand GSS is characterised by a high percentage of Ni, Cr, Cu, etc., on the other hand DBC is characterised by Co and Cu high content. In general, sludge, management of which in Italy is administered in accordance with the Italian Legislative Decree 152/06, can be used as waste from for environmental restoration or for cement plants. Several researches investigate the possible reuse of these materials but, at present time, there is no evidence of its systematic recovery as "recycled product" or "by-product". On the basis of the results of these researches it is possible to highlight

  1. Reducing the startup time of aerobic granular sludge reactors through seeding floccular sludge with crushed aerobic granules. (United States)

    Pijuan, Maite; Werner, Ursula; Yuan, Zhiguo


    One of the main challenging issues for the aerobic granular sludge technology is the long startup time when dealing with real wastewaters. This study presents a novel strategy to reduce the time required for granulation while ensuring a high level of nutrient removal. This new approach consists of seeding the reactor with a mixture of crushed aerobic granules and floccular sludge. The effectiveness of the strategy was demonstrated using abattoir wastewater, containing nitrogen and phosphorus at approximately 250 mgN/L and 30 mgP/L, respectively. Seven different mixtures of crushed granules and floccular sludge at granular sludge fractions (w/w in dry mass) of 0%, 5%, 10%, 15%, 25%, 30% and 50% were used to start eight granulation processes. The granulation time (defined as the time when the 10th percentile bacterial aggregate size is larger than 200 μm) displayed a strong dependency on the fraction of granular sludge. The shortest granulation time of 18 days was obtained with 50% crushed granules, in comparison with 133 days with 5% crushed granules. Full granulation was not achieved in the two trials without seeding with crushed granules. In contrast to the 100% floccular sludge cases, where a substantial loss of biomass occurred during granulation, the biomass concentration in all other trails did not decrease during granulation. This allowed that good nitrogen removal was maintained in all the reactors during the granulation process. However, enhanced biological phosphorus removal was achieved in only one of the eight trials. This was likely due to the temporary accumulation of nitrite, a strong inhibitor of polyphosphate accumulating organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Fast pyrolysis of lignin, macroalgae and sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Trinh, N.T.


    Non-conventional biomass feedstock may also be applicable for fast pyrolysis processes. Among the forms of non-conventional biomasses, macroalgae, lignin (industrial residue) and sewage sludge may be attractive materials due to their low price, non-competitiveness with food crops and the possible utilization of solid wastes. Besides, a fast pyrolysis process can be used as a process to densify the biomass and produce bioslurry, a mixture of bio-oil and pyrolytic char. The bioslurry is found to be a possible feedstock for pressurized gasification plants. Thus, the aims of this project are to investigate fast pyrolysis properties of lignin, sewage sludge and macroalgae on a lab scale PCR and characterize their bio-oil properties. Bioslurry properties with respect to use as a feedstock for pressurized gasification is also investigated. Lignin and sewage sludge PCR pyrolysis provided bio-oil yields of 47 and 54 wt% daf, and oil energy recovery of 45 and 50 %, respectively. While the macroalgae PCR pyrolysis showed promising results with an organic oil yield of 65 wt% daf and an oil energy recovery of 76 %. The HHV of the lignin, sewage sludge and macroalgae oils were 29.7, 25.7 and 25.5 MJ/kg db respectively, and that are higher than that of typical bioiv oil from conventional biomasses (23-24 MJ/kg db). Almost all metals feedstock contents were contained in the chars at temperatures of 550 - 575 deg. C for lignin, sewage sludge and macroalgae PCR pyrolysis. Due to high feedstock nitrogen and sulfur contents, also a high level of nitrogen and sulfur of macroalgae and sewage sludge oils were observed compared to conventional bio-oil and this may limit their further industrial applications. The lignin char had a high proportion of small size particles, a HHV of 21 MJ/kg db and were almost free of chloride and sulfur, thus it is considered as a promising fuel for gasification or combustion; whereas macroalgae and sewage sludge chars containing high amounts of

  3. Anaerobic digestion of pulp and paper mill wastewater and sludge. (United States)

    Meyer, Torsten; Edwards, Elizabeth A


    sludge) and primary sludge is still in its infancy. Current research is mainly focused on developing efficient pretreatment methods that enable fast hydrolysis of complex organic matter, shorter sludge residence times and as a consequence, smaller sludge digesters. Previous experimental studies indicate that the anaerobic digestibility of non-pretreated biosludge from pulp and paper mills varies widely, with volatile solids (VS) removal rates of 21-55% and specific methane yields ranging between 40 and 200 mL g(-1) VS fed. Pretreatment can increase the digestibility to some extent, however in almost all reported cases, the specific methane yield of pretreated biosludge did not exceed 200 mL g(-1) VS fed. Increases in specific methane yield mostly range between 0 and 90% compared to non-pretreated biosludge, whereas larger improvements were usually achieved with more difficult-to-digest biosludge. Thermal treatment and microwave treatment are two of the more effective methods. The heat required for the elevated temperatures applied in both methods may be provided from surplus heat that is often available at pulp and paper mills. Given the large variability in specific methane yield of non-pretreated biosludge, future research should focus on the links between anaerobic digestibility and sludge properties. Research should also involve mill-derived primary sludge. Although biosludge has been the main target in previous studies, primary sludge often constitutes the bulk of mill-generated sludge, and co-digestion of a mixture between both types of sludge may become practical. The few laboratory studies that have included mill primary sludge indicate that, similar to biosludge, the digestibility can range widely. Long-term studies should be conducted to explore the potential of microbial adaptation to lignocellulosic material which can constitute more than half of the organic matter in pulp and paper mill sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.


    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D.; Koopman, D.


    Testing was completed to demonstrate the viability of the newly developed glycolic acid/formic acid flowsheet on processing in the Defense Waste Processing Facility's (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in DWPF. Four sludge simulants were prepared to cover two compositional ranges in the waste. The first was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium (referred to as HiMn or LoMn in this report). These two options can be combined to form four distinct sludge compositions. The sludge matrix study called for testing each of these four simulants near the minimum acid required for nitrite destruction (100% acid stoichiometry) and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid (150% acid stoichiometry). Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants were used for high and low acid testing. Eight planned experiments (GF26 to GF33) were completed to demonstrate the viability of the glycolic-formic flowsheet. Composition and physical property measurements were made on the SRAT product. Composition measurements were made on the condensate from the Mercury Water Wash Tank (MWWT), Formic Acid Vent Condenser (FAVC), ammonia scrubber and on SRAT samples pulled throughout the SRAT cycle. Updated values for formate loss and nitrite-tonitrate conversion were found that can be used in the acid calculations for future sludge matrix process simulations with the glycolic acid/formic acid

  5. The Effect of Lime Stabilization on the Microbiological Quality of Sewage Sludge

    Directory of Open Access Journals (Sweden)

    B Bina, H Movahedian, I Kord


    Full Text Available Agricultural utilization of wastewater sludge is practiced in many parts of the world. Sludge may contain a variety of pathogenic microorganisms, which can spread diseases if there is human exposure to the sludge. Therefore, sludge must be treated before disposal and reuse. In this study the effect of liming on the microbiological quality of urban liquid raw sludge in Isfahan Wastewater Treatment Plant (IWTP was investigated. Sludge samples were taken from IWTP, and the initial concentrations of total solids, volatile solids, total coliform, fecal coliform, Salmonella and ova of parasites were determined. Then adding lime to increase the pH of sludge to 11 and 12 and the effect of liming on the parameters was carried out after 2, 24, 72 and 120 hours. Salmonella was inactivated completely in treated sludge after two hours. The removal of up to 99% of fecal coliform was obtained for two ranges of pH. However, reduction of ova of parasites at pH 11 and 12 after five days were found only 56% and 83.8% respectively. Sludge treated with lime meets USA Environmental Protection Agency (EPA standards regarding Class B and Class A after 2 and 24 hours respectively. At pH higher than 11 and 12 treated sludge with lime meets vector attraction reduction requirements after two hours. However, at a pH higher than 11 and 12 treated sludge with lime does not meet the guideline for pathogen reduction of class a regarding eggs of parasites.

  6. Mineralization of nitrogen from pelletized sewage sludge - a laboratory incubation study

    Energy Technology Data Exchange (ETDEWEB)

    Wattiez, Anne-Laure


    Nitrogen limits the productivity of most ecosystems, but can also cause environmental problems. With the increasing amount of sludge generated by better wastewater treatment, land application of pelletized sludge appears as a combined solution to waste disposal and plant nitrogen nutrition issues. Six types of sludge pellets/granules, containing different mixtures of sludge, ash and/or lime have been inoculated and incubated for 8 weeks at 20 deg C in the dark, to study N net mineralisation rates. Laboratory results showed no indication of general differences between sludge/ash and sludge/lime mixtures, with respect to N mineralisation and nitrification, but some differences between Umeaa pellets and GaevIe granules were discernible. The higher net N mineralisation rates in pellets appeared to be related to sludge properties. On the contrary pellets had a low level of nitrification, which might be explained by preliminary heat treatment of the sludge and the seemingly slow recolonization of nitrifiers. It is also believed that considerable amounts of N were lost, and that the major route for these losses was ammonia volatilisation. From an economical point of view, sludge pelletisation appears to be the most cost-effective means of disposal. It transforms sludge into a valuable, odourless and storable fertiliser or heat source. Some income could even be expected. The benefits obtained from an increased tree growth could justify forest fertilisation with pelletized sludge, but further research is needed to determine more precisely the possible growth increment and the consequences on the environment.

  7. The investigation of different pollutants and operation processes on sludge toxicity in sequencing batch bioreactors. (United States)

    Chen, Xiurong; Zhao, Jianguo; Bao, Linlin; Wang, Lu; Zhang, Yuying


    The influence of different target pollutants and operation modes in sequencing batch bioreactors (SBRs) on sludge toxicity was compared in this study. Sludge toxicity was characterized by the inhibiting luminosity through using luminescent bacterium Photobacterium phosphoreum (P. phosphoreum) during either gradual acclimation or impaction processes with synthetic wastewater containing high-strength bisphenol A (BPA) or N, N-dimethylformamide (DMF). When the activated sludge was first acclimated with either 120 mg/L DMF or 20 mg/L BPA, and then respectively increased to 200 mg/L DMF and 40 mg/L BPA it was defined as gradual acclimation process, whereas when the activated sludge was, respectively, injected with 200 mg/L DMF and 40 mg/L BPA directly it was defined as impaction process. Results showed that the toxicity of the impacted sludge was greater than that of the gradual acclimated sludge, especially in the initial stage before 10 d. Activated sludge treating BPA synthetic wastewater exhibited higher toxicity due to the more inhibition of BPA to sludge activity compared to that of DMF. The proteomics analysis indicated that the stress responses of activated sludge to DMF and BPA stimulation were both significant. In turn, the secretions from two kinds of sludge under stress conditions contributed to sludge toxicity.

  8. Evaluation-of soil enzyme activities as soil quality indicators in sludge-amended soils. (United States)

    Dindar, Efsun; Şağban, Fatma Olcay Topaç; Başkaya, Hüseyin Savaş


    Soil enzymatic activities are commonly used as biomarkers of soil quality. Several organic and inorganic compounds found in municipal wastewater sludges can possibly be used as fertilizers. Monitoring and evaluating the quality of sludge amended soils with enzyme activities accepted as a beneficial practice with respect to sustainable soil management. In the present study, variation of some enzyme activities (Alkaline phosphatase, dehydrogenase, urease and beta-glucosidase activities) in soils amended with municipal wastewater sludge at different application rates (50, 100 and 200 t ha(-1) dry sludge) was evaluated. Air dried sludge samples were applied to soil pots and sludge-soil mixtures were incubated during a period of three months at 28 degrees C. The results of the study showed that municipal wastewater sludge amendment apparently increased urease, dehydrogenase, alkaline phosphatase and P-glucosidase activities in soil by 48-70%, 14-47%, 33-66% and 9-14%, respectively. The maximum activity was generally observed in sludge amended soil with dose of 200 t ha(-1). Urease activity appeared to be a better indicator of soil enhancement with wastewater sludge, as its activity was more strongly increased by sludge amendment. Accordingly, urease activity is suggested to be soil quality indicator best suited for measuring existing conditions and potential changes in sludge-amended soil.

  9. The influence of SBR parameters on the sludge toxicity of synthetic wastewater containing bisphenol A. (United States)

    Chen, Xiurong; Zhao, Jianguo; Zhao, Jun; Yang, Na; Zhang, Fei; Jiang, Zijian


    Synthetic wastewater with bisphenol A (BPA) concentrations of 7.5, 20, and 40 mg/L was treated with activated sludge sequential batch reactors (SBRs). The sludge acute toxicity indicated by the inhibitory ratio to luminous bacteria T3 was evaluated. The influent COD was controlled at approximately 300 mg/L, and aerobic conditions were maintained in the SBR. It was found that the process of BPA biodegradation, as opposed to BPA adsorption, contributed to the formation of sludge toxicity; there was a positive relationship between sludge toxicity and influent BPA concentration, and the toxicity centralized in intracellular regions and the intersection of extracellular polymeric substances (EPS) in sludge flocs. Since the BPA biodegradation process dedicated to sludge toxicity, the influence of key operational parameters such as sludge retention time (SRT) and hydraulic retention time (HRT) on sludge toxicity were investigated. It was founded that sludge toxicity decreased significantly when SRT and HRT were shortened from 20 to 10 days and 12 to 8 h, respectively. The results of Pearson correlation analysis indicated that the Shannon index H of the bacterial community correlated significantly to sludge toxicity. The results from both similarity analysis and UPGMA indicated that influent quality characteristic contributes much more to bacterial community than operation parameters, and then leads to difference between blank and control sludge toxicity.

  10. Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment. (United States)

    Ning, Xun-An; Wen, Weibin; Zhang, Yaping; Li, Ruijing; Sun, Jian; Wang, Yujie; Yang, Zuoyi; Liu, Jingyong


    The effects of micro-electrolysis treatment on textile dyeing sludge dewatering and its mechanisms were investigated in this study. Capillary suction time (CST) and settling velocity (SV) were used to evaluate sludge dewaterability. Extracellular polymeric substances (EPS) concentration and sludge disintegration degree (DDSCOD) were determined to explain the observed changes in sludge dewaterability. The results demonstrated that the micro-electrolysis could significantly improve sludge dewaterability by disrupting the sludge floc structure. The optimal conditions of sludge dewatering were the reaction time of 20 min, initial pH of 2.5, Fe/C mass ratio of 1/1, and the iron powder dosage of 2.50 g/L, which achieved good CST (from 34.1 to 27.8 s) and SV (from 75 to 60%) reduction efficiency. In addition, the scanning electron microscope (SEM) images revealed that the treated sludge floc clusters are broken up and that the dispersion degree is better than that of a raw sludge sample. The optimal EPS concentration and DDSCOD to obtain maximum sludge dewaterability was 43-46 mg/L and 4.2-4.9%, respectively. The destruction of EPS was one of the primary reasons for the improvement of sludge dewaterability during micro-electrolysis treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The impact of sewage sludge compost on tree peony growth and soil microbiological, and biochemical properties. (United States)

    Xue, Dong; Huang, Xiangdong


    In order to assess the suitability of sludge compost application for tree peony (Paeonia suffruticosa)-soil ecosystems, we determined soil microbial biomass C (Cmic), basal respiration (Rmic), enzyme activities, and tree peony growth parameters at 0-75% sludge compost amendment dosage. Soil Cmic, Rmic, Cmic as a percent of soil organic C, enzyme (invertase, urease, proteinase, phosphatase, polyphenoloxidase) activities, and plant height, flower diameter, and flower numbers per plant of tree peony significantly increased after sludge compost amendment; however, with the increasing sludge compost amendment dosage, a decreasing trend above 45% sludge compost amendment became apparent although soil organic C, total Kjeldahl N, and total P always increased with the sludge compost amendment. Soil metabolic quotient first showed a decreasing trend with the increasing sludge compost application in the range of 15-45%, and then an increasing trend from compost application of 45-75%, with the minimum found at compost application of 45%. As for the diseased plants, 50% of tree peony under the treatment without sludge compost amendment suffered from yellow leaf disease of tree peony, while no any disease was observed under the treatments with sludge compost application of 30-75%, which showed sludge compost application had significant suppressive effect on the yellow leaf disease of tree peony. This result convincingly demonstrated that ≤45% sludge compost application dosage can take advantage of beneficial effect on tree peony growth and tree peony-soil ecosystems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Flocculation and dewaterability of chemically enhanced primary treatment sludge by bioaugmentation with filamentous fungi. (United States)

    Murugesan, Kumarasamy; Selvam, Ammaiyappan; Wong, Jonathan W C


    In this study, filamentous fungal strains isolated from sewage sludge bioleached with iron-oxidizing bacteria were evaluated their effectiveness in improving the flocculation and dewaterability of chemically enhanced primary treatment (CEPT) sludge. Augmentation of the pre-grown mycelial biomass in the CEPT sludge had no significant changes in sludge pH but, improved sludge dewaterability, as evidenced from the decrease in capillary suction time. Improvement on sludge flocculation and dewaterability depended on the fungal strains, and a pellet forming Penicillium sp. was more effective than the fungal isolates producing filamentous form of mycelial biomass due to entrapment of sludge solids onto mycelial pellets. Fungal treatment also reduced the chemical oxygen demand of the CEPT sludge by 35-76%. Supplementation metal cations (Ca(2+), Mg(2+), and Fe(3+)) to fungal pre-augmented sludge rapidly improved the sludge dewaterability. This study indicates that augmentation of selective fungal biomass can be a potential method for CEPT sludge flocculation and dewaterability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Pretreatment on Anaerobic Sludge for Enhancement of Biohydrogen Production from Cassava Processing Wastewater

    Directory of Open Access Journals (Sweden)

    Franciele do Carmo Lamaison


    Full Text Available Methods for the enrichment of an anaerobic sludge with H2-producing bacteria have been compared by using cassava processing wastewater as substrate.The sludge was submitted to three different pretreatments: 1 heat pretreatment by boiling at 98 °C for 15 min., 2 heat pretreatment followed by sludge washout in a Continuous Stirring Tank Reactor (CSTR operated at a dilution rate (D of 0.021 h-1, and 3 sludge washout as the sole enrichment method. The pretreated sludge and the sludge without pretreatment (control were employed in the seeding of 4 batch bioreactors, in order to verify the volume and composition of the generated biogas. Maximum H2 production rates (Rm from the pretreated sludges, were estimated by the modified Gompertz model. Compared to the control, H2 production was ca. 4 times higher for the sludge submitted to the heat pretreatment only and for the sludge subjected to heat pretreatment combined with washout, and 10 times higher for washout. These findings demonstrated that the use of sludge washout as the sole sludge pretreatment method was the most effective in terms of H2 production, as compared to the heat and to the combined heat and washout pretreatments.

  14. Analysis of petroleum oily sludge producing in petroleum field of Rio Grande do Norte, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Cicero de Souza; Lima, Regineide Oliveira; Silva, Edjane Fabiula Buriti da; Castro, Kesia Kelly Vieira de; Chiavone Filho, Osvaldo; Araujo, Antonio Souza de [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)


    In exploration and production of petroleum is generated solid waste different and components other. The petroleum oily sludge is a complex mix of components different (water, oil and solid). The petroleum oily sludge generally has other residues and is formed during production and operations, transport, storage and petroleum refining (atmospheric residue, vacuum residue and catalytic cracking residue). However, according to its origin, the compositions can be found quite varied for sludge. Observing the process steps production and refining is possible to locate its main sources and percentage contributions in terms of waste generation. The elemental analysis was performed with oily sludge from region and it showed different composition. For carbon element and hydrogen, small differences was observed, but for was observed greater differences for Oxygen element. The sludge has different inorganic and organic composition. The sludge from oil water separator (OWS) 2 showed a greater amount of oil (94.88%), this may indicate a residue of aggregate high for petroleum industry. In analysis of Saturates, Aromatics, Resins and Asphaltenes (SARA), the sludge from unloading showed amount high of saturates. The inorganic material separated from sludge was characterized and sludge from OWS 2 had high amount sulfur (41.57%). The sludge analyzed showed organic components high values, so it can be treated and reprocessed in process units petroleum industry. The analysis thermal degradation had a better setting for treated oily sludge. (author)

  15. Biological Composition of Sewage Sludge in the Aspect of Threats to the Natural Environment

    Directory of Open Access Journals (Sweden)

    Bień January


    Full Text Available One of the prerequisites for sustainable development is integrated waste management, including sewage sludge. Besides its good fertilization properties, sewage sludge, which is an inevitable by-product of sewage treatment, accumulates toxic chemical substances and dangerous pathogenic and toxicogenic organisms. Uncontrolled introduction of sewage sludge into soil might pose a serious threat to food chain and natural soil microflora. This in effect might disturb the ecological balance in a particular ecosystem. This study presents author’s own investigations of the sanitary conditions of sewage sludge and the conditions after the processes of aerobic and anaerobic stabilization. The investigated sewage sludge originated from a municipal wastewater treatment plant. The sewage sludge samples were transferred onto proliferation and diagnostic media. The results of the analysis obtained in this study confirmed that sewage sludge is a material which is rich in microorganisms, including pathogenic bacterial species such as: Escherichia coli and Salmonella typhimurium. Mycological tests demonstrated that sewage sludge is a material which is conducive to proliferation of yeast-like and mould-like fungi, among which both pathogenic and toxinogenic species can be present. Quantitative analysis of the investigated sewage sludge demonstrated that the processes of stabilization reduce the content of microorganisms but they do not guarantee product safety in sanitary terms. A huge variability and variety of biological composition points to the need for further research in the field of sanitary characteristics of sewage sludge and survival rate in microorganisms from different types of sewage sludge.

  16. Improved dechlorinating performance of upflow anaerobic sludge blanket reactors by incorporation of Dehalospirillum multivorans into granular sludge

    DEFF Research Database (Denmark)

    Hörber, Christine; Christiansen, Nina; Arvin, Erik


    was compared to the reference 1 (R1) reactor, where the granules were autoclaved to remove all dechlorinating abilities before inoculation, and to the reference 2 (R2) reactor, containing only living granular sludge. All three reactors were fed mineral medium containing 3 to 57 mu M PCE, 2 mM formate, and 0...... to DCE, even at HRTs much lower than the reciprocal maximum specific growth rate of D. multivorans, indicating that this bacterium was immobilized in the living and autoclaved granular sludge. In contrast, the R2 reactor, with no inoculation of D. multivorans, only converted PCE to TCE under the same...

  17. Leaching of Heavy Metals Using SPLP Method from Fired Clay Brick Incorporating with Sewage Sludge (United States)

    Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Amira Sarani, Noor; Aqma Izurin Rahmat, Nur


    Sewage sludge is a by-product generate from wastewater treatment process. The sewage sludge contains significant trace metal such as Cr, Mn, Ni, Cu, Zn, As, Cd and Pb which are toxic to the environment. Sewage sludge is disposed of by landfilling method. However, this option not suitable because of land restriction and environmental control regulations imposed. Therefore, sewage sludge from wastewater treatment plant was incorporated into fired clay brick to produce good quality of brick as well as reducing heavy metals from sludge itself. Sewage sludge with 0%, 1%, 5%, 10% and 20% of were incorporated into fired clay bricks and fired at 1050°C temperature with heating rates of 1°C/min. The brick sample then crushed and sieved through 9.5 mm sieve for Synthetic Precipitation Leaching Procedure (SPLP). From the results, incorporation up to 20% of sewage sludge has leached less heavy metals and compliance with USEPA standard.

  18. Effect of gamma-ray irradiation on the dewaterability of waste activated sludge (United States)

    Wu, Yuqi; Jiang, Yinghe; Ke, Guojun; Liu, Yingjiu


    The effect of gamma-ray irradiation on waste activated sludge (WAS) dewaterability was investigated with irradiation doses of 0-15 kGy. Time to filter (TTF50), specific resistance of filtration (SRF) and water content of sludge cake were measured to evaluate sludge dewaterability. Soluble chemical oxygen demand (SCOD), soluble extracellular polymeric substances (EPS) concentration and sludge particle size were determined to explain changes in sludge dewaterability. The optimal irradiation dose to obtain the maximum dewaterability characteristics was 1-4 kGy, which generated sludge with optimal disintegration (1.5-4.0%), soluble EPS concentration (590-750 mg/L) and particle size distribution (100-115 μm diameter). The combination of irradiation and cationic polyacrylamide (CPAM) addition exhibited minimal synergistic effect on increasing sludge dewatering rate compared with CPAM conditioning alone.

  19. Extracellular protein analysis of activated sludge and their functions in wastewater treatment plant by shotgun proteomics. (United States)

    Zhang, Peng; Shen, Yu; Guo, Jin-Song; Li, Chun; Wang, Han; Chen, You-Peng; Yan, Peng; Yang, Ji-Xiang; Fang, Fang


    In this work, proteins in extracellular polymeric substances extracted from anaerobic, anoxic and aerobic sludges of wastewater treatment plant (WWTP) were analyzed to probe their origins and functions. Extracellular proteins in WWTP sludges were identified using shotgun proteomics, and 130, 108 and 114 proteins in anaerobic, anoxic and aerobic samples were classified, respectively. Most proteins originated from cell and cell part, and their most major molecular functions were catalytic activity and binding activity. The results exhibited that the main roles of extracellular proteins in activated sludges were multivalence cations and organic molecules binding, as well as in catalysis and degradation. The catalytic activity proteins were more widespread in anaerobic sludge compared with those in anoxic and aerobic sludges. The structure difference between anaerobic and aerobic sludges could be associated with their catalytic activities proteins. The results also put forward a relation between the macro characteristics of activated sludges and micro functions of extracellular proteins in biological wastewater treatment process.

  20. Comparative Research on EPS Extraction from Mechanical Dewatered Sludge with Different Methods

    Directory of Open Access Journals (Sweden)

    Weiyun Wang


    Full Text Available In order to find a suitable extracellular polymer substance (EPS extraction method for mechanical dewatered sludge, four different methods including EDTA extraction, alkali extraction, acid extraction, ultrasonic extraction method have been used in extracting EPS from belt filter dewatered sludge. The contents of polysaccharide and proteins extracted from the dewatered sludge by different extraction methods are also analyzed. The results indicated that EDTA method and alkali extraction method are more suitable for dewatered sludge with more EPS content and less cell damage, while sulfuric acid extraction and ultrasonic extraction were poorer with obvious cell lysis shown by higher DNA content in extracted EPS. Contents of proteins and polysaccharide in EPS extracted from mechanical dewatered sludge, is at the contents between that in EPS extracted from activated sludge and anaerobic digestion sludge.

  1. Sludge hygienization: Helminth eggs destruction by lime treatment Ascaris eggs as model

    Energy Technology Data Exchange (ETDEWEB)

    Banas, S.; Schwartzbrod, J. [Lab. de Chimie Physique et Microbiologie de l' Environnement, Nancy (France); Remy, M. [Lhoist, on behalf of the European Lime Assoication (EuLA), Bruessel (Germany); Boehm, R. [Univ. Hohenheim, Stuttgart (Germany); Verfuerden, M. [Fels-Werke GmbH, im Namen des Bundesverbandes der Deutschen Kalkindustrie (BVK), Koeln (Germany)


    Most pathogens in the raw sewage are concentrated into the sewage sludge. They can be separated into four categories: viruses, bacteria, protozoa and larger parasites such as human roundworms, tapeworms and liver flukes. Such micro-organisms can cause disease in humans, the transmission occurring in several ways e.g. by inhaling sludge aerosols or dust, by eating vegetables or fruits contaminated by sludge, drinking water contaminated by run-off or by eating meat from livestock infected by grazing pastures fertilised with sludge. The presence of helminth eggs in urban sludge may constitute a sanitary risk when used as agricultural fertiliser. To avoid any contamination, the efficiency of a certain number of sludge hygienization processes must be tested. One of these involves decontamination with quicklime. The Ascaris egg inactivation by liming with lime milk, slaked lime and quicklime is studied in a series of sludges coming from slaughterhouses. (orig.)

  2. Biogas potential from anaerobic co-digestion of faecal sludge with food waste and garden waste (United States)

    Afifah, Ukhtiy; Priadi, Cindy Rianti


    The limited faecal sludge management can be optimized by converting the sludge into biogas. This study purposed to optimize the biogas potential of faecal sludge with food waste and garden waste. The system using Anaerobic Co-digestion on the variation 25% and 50% concentration of faecal sludge based on Volatile Solids (VS). Inoculum used was cow's rumen. The study was operated using lab-scale batch reactor 51 L for 42 days. Biogas produced at 25% concentration of faecal sludge is 0,30 m3CH4/kg with 71,93% VS and 72,42% COD destruction. Meanwhile, at 50% concentration of faecal sludge produce 0,56 m3CH4/kg VS biogas with 92,43% VS and 87,55% COD destruction. This study concludes that biogas potential of 50% concentration greater than 25% concentration of faecal sludge.

  3. Utilization of Brine Sludge in Nonstructural Building Components: A Sustainable Approach

    Directory of Open Access Journals (Sweden)

    Mridul Garg


    Full Text Available The characterization and influence of brine sludge on the properties of cement-fly ash-sludge binders are presented. The reaction products formed during the hydration of binder provide an interlocking framework to physically encapsulate the waste particles and are responsible for the development of strength. The utilization of brine sludge in making paver blocks and bricks and the effect of sludge concentration on the engineering properties of these products are also discussed. These results clearly exhibited that brine sludge up to 35 and 25% can safely be utilized for making paver blocks and bricks, respectively. The leachability studies confirm that the metals ions and impurities in the sludge are substantially fixed in the matrix and do not readily leach from there. The utilization of brine sludge in construction materials could serve as an alternative solution to disposal and reduce pollution.



    Rocío VACA


    The use of organic wastes in agriculture can improve the soil's productive capacity, and physical and chemical characteristics. This study evaluated the effects of sewage sludge, sewage sludge compost and inorganic fertilizer applications on nickel, copper and zinc contents in soil and corn grains (Zea mays L); maize productivity, and grain nutritional quality. Sewage sludge and sewage sludge compost at 18 Mg ha¿1 and a mineral fertilizer (N-P-K) with a formulation of 150-75-30 were applied. ...

  5. Characterization of Tank 51 Sludge Slurry Samples (HTF-51-17-67, -68, -69, -74, -75, and -76) in Support of Sludge Batch 10 Processing

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reboul, S. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) Engineering (SRR-E) to provide sample characterization and analyses of Tank 51 sludge samples in support of Sludge Batch (SB) 10. The six Tank 51 sludge samples were sampled and delivered to SRNL in August of 2017. These six Tank 51 sludge samples, after undergoing physical characterizations which included rheology, weight percent total solid, dissolved solids and density measurements, were combined into one composite Tank 51 sample and analyzed for corrosion controls analytes, select radionuclides, chemical elements, density and weight percent total solids.

  6. Characterization of tank 51 sludge samples (HTF-51-17-44/ HTF-51-17-48) in support of sludge batch 10 processing

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) Engineering (SRR-E) to provide sample characterization and analyses of Tank 51 sludge samples in support of Sludge Batch (SB) 10. The two Tank 51 sludge samples were sampled and delivered to SRNL in May of 2017. These two tank 51 sludge samples were combined into one composite sample and analyzed for corrosion controls analytes, select radionuclides, chemical elements, density and weight percent total solids and aluminum hydroxides (gibbsite and boehmite) by x-ray diffraction.

  7. Sludge accumulation and distribution impact the hydraulic performance in waste stabilisation ponds. (United States)

    Coggins, Liah X; Ghisalberti, Marco; Ghadouani, Anas


    Waste stabilisation ponds (WSPs) are used worldwide for wastewater treatment, and throughout their operation require periodic sludge surveys. Sludge accumulation in WSPs can impact performance by reducing the effective volume of the pond, and altering the pond hydraulics and wastewater treatment efficiency. Traditionally, sludge heights, and thus sludge volume, have been measured using low-resolution and labour intensive methods such as 'sludge judge' and the 'white towel test'. A sonar device, a readily available technology, fitted to a remotely operated vehicle (ROV) was shown to improve the spatial resolution and accuracy of sludge height measurements, as well as reduce labour and safety requirements. Coupled with a dedicated software package, the profiling of several WSPs has shown that the ROV with autonomous sonar device is capable of providing sludge bathymetry with greatly increased spatial resolution in a greatly reduced profiling time, leading to a better understanding of the role played by sludge accumulation in hydraulic performance of WSPs. The high-resolution bathymetry collected was used to support a much more detailed hydrodynamic assessment of systems with low, medium and high accumulations of sludge. The results of the modelling show that hydraulic performance is not only influenced by the sludge accumulation, but also that the spatial distribution of sludge plays a critical role in reducing the treatment capacity of these systems. In a range of ponds modelled, the reduction in residence time ranged from 33% in a pond with a uniform sludge distribution to a reduction of up to 60% in a pond with highly channelized flow. The combination of high-resolution measurement of sludge accumulation and hydrodynamic modelling will help in the development of frameworks for wastewater sludge management, including the development of more reliable computer models, and could potentially have wider application in the monitoring of other small to medium water bodies

  8. Study on the effect and mechanism of hydrothermal pretreatment of dewatered sewage sludge cake for dewaterability. (United States)

    Zhu, Ying; Han, Zhe; Liu, Xiuyu; Li, Jing; Liu, Feng; Feng, Suping


    In China, over 17 million tons dewatered sewage sludge cake (DSSC), with about 80% water content, was generated from wastewater treatment plants in 2010. High water content is the bottleneck of sludge treatment and disposal. In this study, the combination of hydrothermal and mechanical treatments has been chosen in order to improve sludge dewaterability. Sludge thermogravimetry analysis was conducted to determine 180 degrees C as the upper-limit hydrothermal temperature. Five temperatures (60, 80, 120, 150, 180 degrees C) were chosen to study the effects of hydrothermal treatment temperature and the holding time on dewaterability. The higher the hydrothermal temperature, the better was the dewaterability character. The water contents of solid products were positively correlated with the hydrothermal holding time at predetermined temperatures in this study. Degradation of macromolecules into acidic compounds could be the reason of pH decrease of separated liquid. Destruction of zoogloe and decomposition of organic matters improved the sludge dewaterability. Sludge dewaterability experiencing hydrothermal processes in this study was negatively correlated with extracellular polymeric substance (EPS) content. With the rising temperature, sludge flocculate disaggregated to small particles generally, this could also be one of the important reasons for sludge dewaterability. High water content is the bottleneck of sludge treatment and disposal. Up to now, only a small amount of research has been conducted to determine whether the dewaterability of dewatered sewage sludge cake can be improved by hydrothermal pretreatment. The mechanism of sludge dewaterability by hydrothermal pretreatment is uncertain. In this study, a new sludge disposal method and corresponding parameters were given. The mechanism of sludge dewaterability was analyzed extensively by extracellular polymeric substances, scanning electron microscope images, element contents, and caloric values, etc. This

  9. Sludge application and monitoring program on the Oak Ridge Reservation, 1986 through 1993

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, C.A.; Boston, H.L.; Van Miegroet, H., Morris, J.L.; Larsen, I.L.; Walzer, A.E.; Adler, T.C.; Bradburn, D.M.; Huq, M.


    Municipal sewage sludge has been applied to forests and pastures on the DOE (U.S. Department of Energy) Oak Ridge Reservation (ORR) since 1983 as a method of both disposal and beneficial reuse. Application was carried out under State of Tennessee permits issued to the City of Oak Ridge for land disposal of. sewage sludge. In conjunction with these applications, information has been collected concerning sludge quantity and characteristics, soil parameters, soil water constituents, groundwater quality, surface runoff water quality, and various chemical constituents in vegetation on application sites. This information provides (1) a record of sludge application on the DOE ORR, and (2) documentation of changes in soil parameters following sludge application. The information also provides a basis for evaluating the implications of the land application of municipal sewage sludge for soil and water quality and for evaluating the fate of sludge constituents when sludge is either sprayed onto or injected into pasture sites or applied to the surface of forested sites. This report covers in detail sludge applications conducted from 1986 through 1993, with some data from the period between 1983 and 1986. Land application has been recommended by the U.S. Environmental Protection Agency as a desirable alternative for disposal of ORR waste. Municipal sewage sludge is in many ways similar to dilute animal manure fertilizer, but it also contains metals, organic chemicals, human pathogens, and other constituents reflective of inputs into the municipal sewage treatment plant. When applied to land, nutrients in the sludge improve soil fertility, and minerals and organic matter in the sludge improve soil structure. Under optimal conditions, metals are immobilized, and organic chemicals and pathogens are immobilized or destroyed. If the sludge is not managed effectively, however, sludge constituents have the potential to affect human health and the environment.

  10. Enzymatic biodiesel production from sludge palm oil (SPO) using ...

    African Journals Online (AJOL)

    Biodiesel is a non-toxic, renewable and environmental friendly fuel. This study involved the production of biodiesel from sludge palm oil ... The results in solvent system for biodiesel production showed that ethanol gave higher yield of biodiesel as compared to methanol. One-factor-at-a time (OFAT) method was applied to ...

  11. Bulking sludge control. Kinetics, substrate storage, and process design aspects

    NARCIS (Netherlands)

    Martins, A.M.P.


    The activated sludge process is the preferred technology for biological wastewater treatment. Despite decades of progress and operation serious operating problems still occur with this process. One major problem is the regular occurrence of excessive growth of filamentous bacteria, phenomena known

  12. The impact of sewage sludge and compost on winter triticale. (United States)

    Kchaou, Rajia; Baccar, Rim; Bouzid, Jalel; Rejeb, Saloua


    There is an increasing interest in the agricultural application of organic waste such as soil amendment, due to the possibility of recycling valuable components, organic matter, and nutrient elements necessary for plant growth. The present study was carried out to evaluate the effects of sewage sludge, and green waste compost application, on a forage crop, triticale "X Triticosecale Wittmack" compared to unfertilized control. The experimental design was installed in the glasshouse conditions at the Regional Field Crop Research Center in Beja, Tunisia. Sewage sludge and green waste compost were added by four rates (0, 5, 10, and 20 t/ha) in soil, 15 days before triticale sowing. The main results showed that plant response differs depending on the type of adding fertilizer. Indeed, compost inputs decreased shoot length and production of triticale, among all sewage sludge rates, by average values of 26 and 60% respectively at final harvest, as compared to unamended soil. However, amendment with different rates of sewage sludge significantly (p < 0.05) increased different plant growth and yield attributes.

  13. A comparative study of faecal sludge management in Malawi and ...

    African Journals Online (AJOL)

    Rochelle Holm

    This review paper covers the issues of pit latrine emptying national policies and regulations with a focus on Malawi and Zambia. ... national policies and regulations taking faecal sludge management into account are weak and have wide gaps in the two study ...... Conference, Hanoi, Vietnam. Malawi Government (2004).

  14. Rising Sludge in Secondary Settlers Due to Denitrification

    DEFF Research Database (Denmark)

    Henze, Mogens; Dupont, Rene; Grau, Peter


    High suspended solids concentrations in settler effluents can be caused by rising sludge, which is the effect of flotation of solids by nitrogen gas resulting from biological denitrification. Many factors influence the nitrogen gas bubble evolution. The most important factor is the rate of biolog...

  15. Preparation of Alumina Nanorods from Chromium-Containing Alumina Sludge (United States)

    Zhang, Xuan; Deng, Bin; Sun, Tong; Li, Wei; Duan, Chang-ping


    Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alumina is strongly restrained by co-doped elements from the chromium-containing alumina sludge. The doped elements change the course of phase structure transformation and slightly transform the chemical bond of the alumina nanorods. The impure elements are doped in the alumina crystal and restrain the crystalline growth of alumina nanorods according to the rules. In the sample prepared from chromium-containing alumina sludge, more Cr and Mg but fewer Fe are doped, and most Cr are existed as Cr(III). It is possible that the Fe-doping is confined by the competition of Cr and Mg. Moreover, the lattice imperfection of alumina is caused by doped ions, such as Cr, Fe, and Mg, and the chemical state of O and Al are affected. The findings by these experiments provide essential information for eliminating pollution and promoting comprehensive utilization of the chromium-containing alumina sludge.

  16. Settleability assessment protocol for anaerobic granular sludge and ...

    African Journals Online (AJOL)

    The re revealed that the protocol was sufficiently sensitive to define the settleability of the sludge samples and to accurately determ their allowable upflow velocities, resultant organic loading rates, and recycling ratios according to the settleability of the gran bed. Also, a series of graphical procedures with settling tests which ...

  17. Enhanced remediation of an oily sludge with saline water ...

    African Journals Online (AJOL)

    This study investigates the potentials of saline (that is, brackish) water to enhance the remediation of an oily sludge, which was part of the waste stream from the improvement project of the Tank Farm at the Bonny Island in the Niger Delta region of Nigeria. Twice weekly, five separate laboratory-scale reactors (labeled A, B, ...

  18. Fungal diversity in activated sludge from membrane bioreactors in Berlin. (United States)

    Awad, Mohamed F; Kraume, M


    The objective of this study was to evaluate the occurrence of fungi in aerobic and anoxic activated sludge from membrane bioreactors. Thirty-six samples from each aerobic and anoxic activated sludge were taken from two membrane bioreactors treating domestic wastewater. Over a period of 9 months, four samples from each plant were taken per month. The samples were prepared for count and identification of fungi. Sixty species belonging to 30 genera were collected from activated sludge samples under aerobic and anoxic conditions. In terms of fungal identification, under aerobic conditions Geotrichum candidum was found at 94.4% followed by Penicillium species at 80.6%, yeasts at 75.0%, and Trichoderma species at 50.0%; under anoxic conditions G. candidum at 86.1%, yeasts at 66.6%, and Penicillium species at 61.1% were the most prevalent. The results indicate that activated sludge is a habitat for growth and sporulation of different groups of fungi, both saprophytic and pathogenic.

  19. Modeling of Seepage Losses in Sewage Sludge Drying Bed ...

    African Journals Online (AJOL)

    In the experiment conducted this study, 125kg of sewage sludge, 90.7% moisture content was thoroughly mixed and intermittently into a sand drying bed of dimensions 1.0m length, 0.3m width, 0.8m depth including overboard and having a 50mm diameter drain pipe. Seepage were measured at 24 hours intervals for 15 ...

  20. Biological sulphate reduction with primary sewage sludge in an ...

    African Journals Online (AJOL)


    and height) was increased from 7.1 to 7.4 ℓ. The increased sludge age allowed more time for the BPO to be hydrolysed as PSS hydrolysis is the rate-limiting process. R2 performance with a PSS COD/SO4. 2- ratio of 1.75 at.

  1. The dechlorination of cyclodiene pesticides by methanogenic granular sludge

    NARCIS (Netherlands)

    Baczynski, T.H.; Grotenhuis, J.T.C.; Knipscheer, P.


    Cyclodiene pesticides: aldrin, isodrin, dieldrin and endrin were dechlorinated by methanogenic granular sludge in spiked batch tests. Initial pesticides concentration was 7 or 9 mg1(-1). Two monodechlorinated analogues were formed during the conversions of aldrin and isodrin. Dieldrin was

  2. Anaerobic granular sludge : characterization, and factors affecting its functioning

    NARCIS (Netherlands)

    Alphenaar, P.A.


    Many UASB reactors are designed in such a fashion that the presence of granular sludge is necessary for a proper purification process. For achieving an optimum wastewater purification with such reactors, knowledge of the factors that determine the growth, retention and disintegration of

  3. Theoretical and practical aspects of modelling activated sludge processes

    NARCIS (Netherlands)

    Meijer, S.C.F.


    This thesis describes the full-scale validation and calibration of a integrated metabolic activated sludge model for biological phosphorus removal. In chapters 1 and 2 the metabolic model is described, in chapters 3 to 6 the model is tested and in chapters 7 and 8 the model is put into practice.

  4. Nitrogen removal from urban wastewater by activated sludge ...

    African Journals Online (AJOL)

    This study deals with nitrogen removal from urban wastewater employing the activated sludge process at low temperature. It aims at determining the performances and rates of nitrification, and characterising the autotrophic biomass (concentration and kinetic parameters) at 11°C and for F/M ratios higher than the ...

  5. In-line rheological characterisation of wastewater sludges using non ...

    African Journals Online (AJOL)

    The performance of a new ultrasound transducer, which can measure velocity profiles non-invasively through high-grade stainless steel pipes, was evaluated for the first time with secondary wastewater sludges. This work is a follow-up study on the feasibility work initially done by the same authors. In-line process control ...

  6. Enzyme Activities in Waste Water and Activated Sludge

    DEFF Research Database (Denmark)

    Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens


    The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...

  7. Modelling of a falling sludge bed reactor using AQUASIM | Ristow ...

    African Journals Online (AJOL)

    The hydrodynamic processes taking place in the FSBR have been simulated using a system of mixed reactors connected by water flow and mass flux streams. Trends obtained from varying the hydraulic retention time, the sludge recycle ratio, and the feed COD: SO4 2- ratio allow for identification of the critical biological ...

  8. Granular sludge formation and characterization in a chain elongation process

    NARCIS (Netherlands)

    Roghair, M.; Strik, D.P.B.T.B.; Steinbusch, K.J.J.; Weusthuis, R.A.; Bruins, M.E.; Buisman, C.J.N.


    Chain elongation is an open-culture biotechnological process which converts short chain fatty acids andan electron donor to medium chain fatty acids (MCFAs). With this letter we present the first observation ofgranular sludge formation in a chain elongation process. This discovery was made in a

  9. Solubilisation of sludge by combined chemical and enzymatic ...

    African Journals Online (AJOL)

    In this study, the effects of cation-binding agents used alone and/or in combination with enzymes on solubilisation of municipal sludge and structure changes were investigated. Formic acid, citric acid, tartaric acid, EDTA, sodium tripolyphosphate (STPP), Zeolite A, sodium fluoride, sodium thiosulphate or sodium silicate were ...

  10. Electrodialytic recovery of phosphorus from chemically precipitated sewage sludge ashes

    DEFF Research Database (Denmark)

    Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M.

    Phosphorus scarcity requires improved recover and reuse of urban sources; the recycling of this nutrient from sewage sludge has become increasingly important in the last years. Using an innovative electrodialytic process, the present study shows the potential for P separation from Fe and Al preci...

  11. Optimization of up-flow anaerobic sludge blanket reactor for ...

    African Journals Online (AJOL)



    Jun 5, 2013 ... Key words: Composite wastewater, up-flow anaerobic sludge blanket (UASB), anaerobic biological treatment, biogas, granulated anaerobic ... collected from the top of the reactor to a flexible water-filled gasholder fitted with .... changes in microbial diversity in biogranules in response to changes in nature ...

  12. Persistent Organic Pollutants in Soil, Sludge and Sediment

    DEFF Research Database (Denmark)

    Vikelsøe, J.; Thomsen, M.; Carlsen, L.

    Occurrence, sources, geographical distribution, transport and fate of the persistent pollutants PAH, NPE, PAE, PCB, PCN and PBDE was investigated in sludge, soil and sediment in a local environment. Further investigated was the vertical distribution in cores of soils and sediment....

  13. Conversion and toxicity characteristics of formaldehyde in acetoclastic methanogenic sludge

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Kleerebezem, R.; Lettinga, G.


    An unadapted mixed methanogenic sludge transformed formaldehyde into methanol and formate. The methanol to formate ratio obtained was 1:1. Formaldehyde conversion proceeded without any lag phase, suggesting the constitutive character of the formaldehyde conversion enzymes involved. Because the rate

  14. Biliary sludge and recurrent ketoacidosis: a case report

    Directory of Open Access Journals (Sweden)

    Kalra Sanjay


    Full Text Available Abstract A five year old boy, weighing 14 kg with no family history of diabetes, presented in frank diabetic ketoacidosis. He recovered, but continued to have episodes of ketoacidosis. He was diagnosed to have biliary sludge, which recovered with insulin treatment.

  15. Modelling of a recycling sludge bed reactor using AQUASIM: reprint ...

    African Journals Online (AJOL)

    The recycling sludge bed reactor (RSBR) allows for increased solids retention time, resulting in greater substrate conversion for all particulate degradation and biological reactions. The purpose of the RSBR is to hydrolyse primary settled sewage (PSS). Soluble products are then used for the biological treatment of acid mine ...

  16. Sludge as dioxins suppressant in hospital waste incineration

    NARCIS (Netherlands)

    Yan, M.; Li, X.; Yang, J.; Chen, T.; Lu, S.; Buekens, A.G.; Olie, K.; Yan, J.


    Nitrogen containing compounds such as ammonia, urea and amines can effectively inhibit the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Sewage sludge accumulates both sulfur and nitrogen during wastewater treatment so it could be used to reduce PCDD/Fs formation.

  17. Response of palm oil sludge on sexual reproductive biology and ...

    African Journals Online (AJOL)

    Experiment on the influence of different rates of palm oil sludge (0, 4000lit/ha, 8000lit/ha, and 12000lit/ha) application on flower initiation and root development of okra (Abelmoschus esculentus), maize (Zea mays L.) and cowpea (Vigna unguiculata (L.) Walp) were investigated in Port Harcourt, Nigeria. The result of the trial ...

  18. A steady state model for anaerobic digestion of sewage sludges ...

    African Journals Online (AJOL)

    ... model for anaerobic digestion of sewage sludge is developed that comprises three sequential parts – a kinetic part from which the % COD removal and methane production are determined for a given retention time; a stoichiometry part from which the gas composition (or partial pressure of CO,sub>2), ammonia released ...

  19. Response of Palm Oil Sludge on Sexual Reproductive Biology and ...

    African Journals Online (AJOL)


    RESPONSE OF PALM OIL SLUDGE ON SEXUAL REPRODUCTIVE BIOLOGY. AND ROOT DEVELOPMENT OF SOME CROPS IN SOUTHERN NIGERIA. ORLUCHUKWU, J.A.. Department of Crop and Soil Science, Faculty of Agriculture,. University of Port Harcourt, P. M. B. 5323, Choba,. Port Harcourt, Rivers State, Nigeria ...

  20. Issues related to waste sewage sludge drying under superheated steam

    Directory of Open Access Journals (Sweden)

    Hamawand Ihsan


    Full Text Available Sewage sludge was dried in a rotary drum dryer under superheated steam. Particle size and moisture content were shown to have significant influences on sticking and agglomeration of the materials. Pouring partially dried sludge (70–80% moisture content, wet basis directly into the screw feeder of the drum dryer resulted in a significant sticking to the surface of the drum and the final particle size of the product was greater than 100 mm in diameter. The moisture content of this product was slightly less than its initial value. To overcome this issue, the sludge was mixed with lignite at variety ratios and then chopped before being introduced to the feeding screw. It was found that mixing the sludge with lignite and then sieving the chopped materials through a four millimetre mesh sieve was the key to solve this issue. This technique significantly reduced both stickiness and agglomeration of the material. Also, this enabled for a significant reduction in moisture content of the final product.

  1. Effect of ultrasonic specific energy on waste activated sludge ...

    African Journals Online (AJOL)



    Mar 22, 2010 ... Key word: Waste activated sludge (WAS), ultrasonic, solubilization, disintegration degree, enzyme activity. ... E-mail: .... treated by ultrasonics at different specific energies, the mean particle size changed dramatically. For example, at the specific energy of 15000 kJ/kg DS, the ...

  2. Gaseous fuels production from dried sewage sludge via air gasification. (United States)

    Werle, Sebastian; Dudziak, Mariusz


    Gasification is a perspective alternative method of dried sewage sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed-bed gasifier installation was designed and built. Two sewage sludge (SS) feedstocks, taken from two typical Polish wastewater treatment systems, were analysed: SS1, from a mechanical-biological wastewater treatment system with anaerobic stabilization (fermentation) and high temperature drying; and (SS2) from a mechanical-biological-chemical wastewater treatment system with fermentation and low temperature drying. The gasification results show that greater oxygen content in sewage sludge has a strong influence on the properties of the produced gas. Increasing the air flow caused a decrease in the heating value of the produced gas. Higher hydrogen content in the sewage sludge (from SS1) affected the produced gas composition, which was characterized by high concentrations of combustible components. In the case of the SS1 gasification, ash, charcoal, and tar were produced as byproducts. In the case of SS2 gasification, only ash and tar were produced. SS1 and solid byproducts from its gasification (ash and charcoal) were characterized by lower toxicity in comparison to SS2. However, in all analysed cases, tar samples were toxic. © The Author(s) 2014.

  3. Investigation of sewage sludge treatment using air plasma assisted gasification. (United States)

    Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis


    This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Optimized operation and design of alternating activated sludge processes

    NARCIS (Netherlands)

    Lukasse, L.J.S.; Keesman, K.J.


    This paper presents a simulation study with the scope to optimise the plant design and operation strategy of 2-reactors alternating activated sludge processes with only flow schedule and aeration on/off as control inputs. The methodology is to simulate the application of receding horizon optimal

  5. Utilisation of Electrodialytically Treated Sewage Sludge Ash in Mortar

    DEFF Research Database (Denmark)

    Kappel, Annemette; Pares Viader, Raimon; Kowalski, Krzysztof Piotr


    Phosphorous is a scarce resource and there is a need to develop methods for recovery of this irreplaceable nutrient from secondary resources, e.g. from sewage sludge ash (SSA). Today SSA is most often disposed of and the resource is lost. In the present study, about 90% phosphorous was recovered ...

  6. Sludge pipe flow pressure drop prediction using composite power ...

    African Journals Online (AJOL)

    ... pipes, the rheology of the fluid plays an important role, especially with increasing concentration of the suspended matter in the sludge. The f-Re relationship is often applied when designing pipelines, but it depends on the rheological parameters of the fluid and what definition of non-Newtonian Reynolds number is used.

  7. Sensitivity study of reduced models of the activated sludge process ...

    African Journals Online (AJOL)

    The problem of derivation and calculation of sensitivity functions for all parameters of the mass balance reduced model of the COST benchmark activated sludge plant is formulated and solved. The sensitivity functions, equations and augmented sensitivity state space models are derived for the cases of ASM1 and UCT ...

  8. Chemical and thermal properties of VIP latrine sludge

    African Journals Online (AJOL)


    Jul 4, 2015 ... thermal conductivity; calorific value and heat capacity. These properties will facilitate the design of faecal sludge emptying and treatment equipment. A manual sorting of the pit contents was carried out to determine the categories and amounts of household waste present. There was a significant difference ...

  9. Use of Natural Zeolite to Upgrade Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Hanife Büyükgüngör


    Full Text Available The objective of this study was to achieve better efficiency of phosphorus removal in an enhanced biological phosphorus removal process by upgrading the system with different amounts of natural zeolite addition. The system performance for synthetic wastewater containing different carbon sources applied at different initial concentrations of phosphorus, as well as for municipal wastewater, was investigated. Natural zeolite addition in the aerobic phase of the anaerobic/aerobic bioaugmented activated sludge system contributed to a significant improvement of phosphorus removal in systems with synthetic wastewater and fresh municipal wastewater. Improvement of phosphorus removal with regard to the control reactors was higher with the addition of 15 than with 5 g/L of natural zeolite. In reactors with natural zeolite addition with regard to the control reactors significantly decreased chemical oxygen demand, ammonium and nitrate, while higher increment and better-activated sludge settling were achieved, without changes in the pH-values of the medium. It was shown that the natural zeolite particles are suitable support material for the phosphate-accumulating bacteria Acinetobacter calcoaceticus (DSM 1532, which were adsorbed on the particle surface, resulting in increased biological activity of the system. The process of phosphorus removal in a system with bioaugmented activated sludge and natural zeolite addition consisted of: metabolic activity of activated sludge, phosphorus uptake by phosphate-accumulating bacteria adsorbed on the natural zeolite particles and suspended in solution, and phosphorus adsorption on the natural zeolite particles.

  10. Urban Sewage Sludge, Sustainability, and Transition for Eco-City

    DEFF Research Database (Denmark)

    Ren, Jingzheng; Liang, Hanwei; Chan, Felix T. S.


    criteria. Three MCDM methods including the sum weighted method, digraph model, and TOPSIS were used to determine sustainability sequence of the alternative technologies for the treatment of urban sewage sludge. Three technologies including landfilling, composting, and drying incineration have been studied...

  11. Phytoremediation of sewage sludge in soils contaminated with ...

    African Journals Online (AJOL)

    The main source of heavy metals in most soils is sewage sludge. Naturally, the heavy metals in soils are transported to vegetations and cultivated crops. These pollutants need to be either reduced or eliminated in the soil to remediate the effects to man, animals, plants, soils, and groundwater. Hence, Jatropha curcas ...

  12. The beneficial usage of water treatment sludge as pottery product ...

    African Journals Online (AJOL)

    Mineralogical compositions were determined using XRD, XRF for chemical composition and physical testing including Atterberg limit test and particles size distribution. Identification of beneficial usage is based on the characteristics of water treatment sludge. Keywords: chemical composition; mineral composition; physical ...


    Directory of Open Access Journals (Sweden)

    Anna Grobelak


    Full Text Available In Poland, sludge management especially in medium and small sewage treatment plants is still a significant problem. According to data from the Central Statistical Office and the report on the implementation of the National Urban Wastewater Treatment Program (in polish KPOŚK land application of sewage sludge remains one of the main methods, although there has been considerable interest known: 'application for other purposes ", where the preparation of composts and fertilizers is included. The use of fertilizer produced from sewage sludge (compost, granules, organic and mineral fertilizers, is regulated by the Act on fertilizers and fertilization, and the relevant implementing rules. For example, they define the test procedure (concerning the quality of fertilizers to enable appropriate permissions to market this type of fertilizers. There is still only several technologies existing on the Polish market dedicated to production of fertilizers in advanced technologies of sewage sludge treatment. Usually the treatment plants are trying to obtain the necessary certificates for generated fertilizers (including composts, or soils substitutes. The advantages of these technologies should be no doubt: the loss of waste status, ability to store the fertilizer and unlimited transportation between areas, sanitization of the product (as a result of the use of calcium or sulfur compounds or temperature should be an alternative for drying technology. While the disadvantages are primarily the investment costs and time consuming certification procedures. However, these solutions enable to maintain the organic matter and phosphorus as well as greater control over possible pollution introduced into the soil.

  14. The efficacy of palm oil sludge in reducing ruminal methanogenesis ...

    African Journals Online (AJOL)

    Treatments were subjected to anaerobic digestion in 10 L bio-digesters. Total gas production, percentage methane production, volatile fatty acids and microbial population of the substrate were measured. Total gas production was significantly suppressed in the treatment having 30% palm oil sludge for about 25 days while ...

  15. Kinetics and reversibility of micropollutant sorption in sludge. (United States)

    Barret, Maialen; Carrère, Hélène; Patau, Mathieu; Patureau, Dominique


    The fate of micropollutants throughout wastewater treatment systems is highly dependent on their sorption interactions with sludge matter. In this study, both the sorption and desorption kinetics of polycyclic aromatic hydrocarbons (PAHs) in activated sludge were shown to be very rapid in comparison to biodegradation kinetics. It was concluded that PAH transfer does not limit their biodegradation and that their fate is governed by the sorption/desorption equilibrium state. The effect of contact time between sludge and PAHs was also investigated. It was shown that aging did not influence the sorption/desorption equilibrium although PAH losses during aging suggest that sequestration phenomena had occurred. This implies that for PAH sorption assessment within treatment processes there is no need to include a contact time dimension. As a consequence, thanks to an innovative approach taking into account sorption equilibria and sequestration, this work has demonstrated that studies in the literature which, in main, deal with micropollutant sorption in sewage sludge with only a short contact time can be extrapolated to real systems in which sorption, desorption and aging occur.

  16. Stepwise hydrolysis to improve carbon releasing efficiency from sludge. (United States)

    Liu, Hongbo; Wang, Yuanyuan; Wang, Ling; Yu, Tiantian; Fu, Bo; Liu, He


    Based on thermal alkaline hydrolysis (TAH), a novel strategy of stepwise hydrolysis was developed to improve carbon releasing efficiency from waste activated sludge (WAS). By stepwise increasing hydrolysis intensity, conventional sludge hydrolysis (the control) was divided into four stages for separately recovering sludge carbon sources with different bonding strengths, namely stage 1 (60 °C, pH 6.0-8.0), stage 2 (80 °C, pH 6.0-8.0), stage 3 (80 °C, pH 10.0) and stage 4 (90 °C, pH 12.0). Results indicate stepwise hydrolysis could enhance the amount of released soluble chemical oxygen demand (SCOD) for almost 2 times, from 7200 to 14,693 mg/L, and the released carbon presented better biodegradability, with BOD/COD of 0.47 and volatile fatty acids (VFAs) yield of 0.37 g VFAs/g SCOD via anaerobic fermentation. Moreover, stepwise hydrolysis also improved the dewaterability of hydrolyzed sludge, capillary suction time (CST) reducing from 2500 to 1600 s. Economic assessment indicates stepwise hydrolysis shows less alkali demand and lower thermal energy consumption than those of the control. Furthermore, results of this study help support the concepts of improving carbon recovery in wastewater by manipulating WAS composition and the idea of classifiably recovering the nutrients in WAS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Examining sludge production in bioelectrochemical systems treating domestic wastewater. (United States)

    Brown, Robert Keith; Harnisch, Falk; Dockhorn, Thomas; Schröder, Uwe


    Sludge production in microbial bioelectrochemical systems (BES) was assessed in conjunction with anaerobic and aerobic control reactors. Effluent after primary settling tank (EAPS) and depleted EAPS spiked with acetate were treated. The reactors were loaded with total suspended solids (TSS) and chemical oxygen demand (COD) at average loading rates of 22 mg TSS d(-1)L(-1) and 86 mg COD d(-1)L(-1), respectively. Carbon cloth anode equipped BES reactors delivered the highest performance. They achieved on average a COD removal of 80%, a Coulomb efficiency of 77% for EAPS, a maximum current density of 39 μA cm(-)(3)/175 μA cm(-)(2) for EAPS and a TSS removal of 59%, yielding a sludge production of only 80 mg TSS per g ΔCOD. This study provides further evidence that BES can improve the economics of wastewater treatment via lower sludge production as well as providing a framework for understanding sludge production in BES. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Thermochemical treatment of sewage sludge ashes for phosphorus recovery. (United States)

    Adam, C; Peplinski, B; Michaelis, M; Kley, G; Simon, F-G


    Phosphorus (P) is an essential element for all living organisms and cannot be replaced. Municipal sewage sludge is a carrier of phosphorus, but also contains organic pollutants and heavy metals. A two-step thermal treatment is suggested, including mono-incineration of sewage sludge and subsequent thermochemical treatment of the ashes. Organic pollutants are completely destroyed by mono-incineration. The resulting sewage sludge ashes contain P, but also heavy metals. P in the ashes exhibits low bioavailability, a disadvantage in farming. Therefore, in a second thermochemical step, P is transferred into mineral phases available for plants, and heavy metals are removed as well. The thermochemical treatment was investigated in a laboratory-scale rotary furnace by treating seven different sewage sludge ashes under systematic variation of operational parameters. Heavy metal removal and the increase of the P-bioavailability were the focus of the investigation. The present experimental study shows that these objectives have been achieved with the proposed process. The P-bioavailability was significantly increased due to the formation of new mineral phases such as chlorapatite, farringtonite and stanfieldite during thermochemical treatment.

  19. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)

    Wastewater discharged from the edible oil industry contains a very concentrated amalgamation of organic and inorganic materials making it a problematic effluent to treat. The aim of this study was to evaluate the activated sludge treatment of edible oil effluent from a sunflower oil processing company in KwaZulu-Natal.

  20. Enzymatic Profiles of Activated Sludge from a Wastewater Treatment ...

    African Journals Online (AJOL)

    Activated sludge samples collected from a treatment plant, with foaming experience in the month of July, was characterized enzymatically. Hexokinase, Glyceraldehyde-3-phosphate dehydrogenase and Adenylate kinase activity assays were conducted before, during and after the foaming episode. The spectrum of enzyme ...

  1. The formulation of synthetic domestic wastewater sludge medium to ...

    African Journals Online (AJOL)

    ABSTRACT. Requirements for successful biological treatment of acid mine drainage (AMD) rely on the reduction of sulphates by microorganisms using a suitable organic carbon source. Various carbon sources, such as domestic wastewater sludge, have previously been used in the semi-passive biological treatment of ...

  2. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)



    Jul 3, 2003 ... Wastewater discharged from the edible oil industry contains a very concentrated amalgamation of organic and inorganic materials making it a problematic effluent to treat. The aim of this study was to evaluate the activated sludge treatment of edible oil effluent from a sunflower oil processing company in ...

  3. Effect of polyaluminium chloride water treatment sludge on effluent ...

    African Journals Online (AJOL)

    Water resources degeneration is accelerated by the discharge of untreated wastewater and its byproducts, hence, reuse of these wastes is a major contributor to sustaining fresh water for the coming decades. In this study, the reuse of polyaluminium water treatment sludge (PA-WTS) as a flocculant aid to improve the ...

  4. Impact of high saline wastewaters on anaerobic granular sludge functionalities

    NARCIS (Netherlands)

    Jeison, D.A.; Rio, del A.; Lier, van J.B.


    Three UASB reactors were operated at different salinity levels in order to assess the effects on the granular sludge properties. High levels of activity inhibition were observed at sodium concentrations over 7 g Na+/L, which resulted in low applicable organic loading rates and VFA accumulation in

  5. Aerobic Granular Sludge : Effect of Substrate on Granule Formation

    NARCIS (Netherlands)

    Pronk, M.


    Discharging untreated wastewater will contaminate the surface waters and can lead to spread of diseases and long term ecological damage. The most common method for treatment is by the activated sludge process. In this process, nutrients like nitrogen, phosphorus and COD are removed by bacteria grown

  6. Sewage, Septage and Faecal Sludge Management in Tamale ...

    African Journals Online (AJOL)

    The sewage, septage and faecal sludge management profile in Tamale Municipality have been studied in relation to the different handling facilities used and the technologies adopted for their treatment and disposal. The human excreta facilities available include pan latrines, public latrines, and water closet systems.

  7. Sewage, Septage and faecal sludge management profile in Ho ...

    African Journals Online (AJOL)

    The paper presents the sewage, septage and faecal sludge management profile in the Ho District of Ghana. The excreta handling facilities available in Ho District are water closet systems, KVIP, pan/bucket latrines and public latrines. About 71 per cent of the population, especially people in the densely populated and low ...

  8. Microscopic Analysis of Plankton, Periphyton, and Activated Sludge. Training Manual. (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    This manual is intended for professional personnel in the fields of water pollution control, limnology, water supply and waste treatment. Primary emphasis is given to practice in the identification and enumeration of microscopic organisms which may be encountered in water and activated sludge. Methods for the chemical and instrumental evaluation…

  9. Chemical and thermal properties of VIP latrine sludge | Zuma | Water ...

    African Journals Online (AJOL)

    The samples were analysed for: moisture content; volatile solids; chemical oxygen demand; ammonia; total Kjeldahl nitrogen; pH; orthophosphate; thermal conductivity; calorific value and heat capacity. These properties will facilitate the design of faecal sludge emptying and treatment equipment. A manual sorting of the pit ...

  10. Modeling sludge accumulation rates in lined pit latrines in slum ...

    African Journals Online (AJOL)

    The main objective of this study was to develop a predictive model for sludge accumulation rates in lined pit latrines in slum areas of Kampala so as to guide routine management of pit latrines. This mathematical model was developed using a mass balance approach with a sample space of 55 lined pits. The developed ...

  11. Phosphorus recovery from sewage sludge ash through an electrodialytic process

    DEFF Research Database (Denmark)

    Guedes, Paula; Couto, Nazare; Ottosen, Lisbeth M.


    The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB...

  12. Recovery of energy from sludge - comparison of the various options

    NARCIS (Netherlands)

    Rulkens, W.H.; Bien, J.D.


    This paper gives a general discussion of existing sludge treatment processes and of innovative treatment options, especially focused on the valuable use of organic carbon compounds as an energy source. Attention is paid both to high and to low temperature processes and to combinations of these

  13. Preparation of Alumina Nanorods from Chromium-Containing Alumina Sludge. (United States)

    Zhang, Xuan; Deng, Bin; Sun, Tong; Li, Wei; Duan, Chang-Ping


    Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alumina is strongly restrained by co-doped elements from the chromium-containing alumina sludge. The doped elements change the course of phase structure transformation and slightly transform the chemical bond of the alumina nanorods. The impure elements are doped in the alumina crystal and restrain the crystalline growth of alumina nanorods according to the rules. In the sample prepared from chromium-containing alumina sludge, more Cr and Mg but fewer Fe are doped, and most Cr are existed as Cr(III). It is possible that the Fe-doping is confined by the competition of Cr and Mg. Moreover, the lattice imperfection of alumina is caused by doped ions, such as Cr, Fe, and Mg, and the chemical state of O and Al are affected. The findings by these experiments provide essential information for eliminating pollution and promoting comprehensive utilization of the chromium-containing alumina sludge.

  14. In-line rheological characterisation of wastewater sludges using non ...

    African Journals Online (AJOL)


    Oct 5, 2015 ... stainless steel pipes, was evaluated for the first time with secondary wastewater sludges. ... It is almost impossible to conduct flow measurements at all in such fluids with optical techniques. The UVP working principle and applications are well ... ers as well as different sensor installation techniques. It was.

  15. Modelling inorganic material in activated sludge systems | Ekama ...

    African Journals Online (AJOL)

    The predicted reactor VSS/TSS ratio reflects the observed relative sensitivity to sludge age, which is low, and to BEPR, which is high. For effective use of the model for design, two significant issues require attention: measurement of the influent ISS concentration, which is not commonly done in wastewater characterisation ...

  16. Extraction of certain heavy metals from sewage sludge using ...

    African Journals Online (AJOL)

    Chemical extraction using inorganic acids (nitric, hydrochloric) and organic acids (citric, oxalic) were tested for extraction of chromium, copper, nickel, lead and zinc from contaminated sewage sludge at different pH and reaction time. Results revealed that solubilization of metals using inorganic acids achieved its maximum ...

  17. Predicting the apparent viscosity and yield stress of mixtures of primary, secondary and anaerobically digested sewage sludge: Simulating anaerobic digesters. (United States)

    Markis, Flora; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam; Slatter, Paul; Eshtiaghi, Nicky


    Predicting the flow behaviour, most notably, the apparent viscosity and yield stress of sludge mixtures inside the anaerobic digester is essential because it helps optimize the mixing system in digesters. This paper investigates the rheology of sludge mixtures as a function of digested sludge volume fraction. Sludge mixtures exhibited non-Newtonian, shear thinning, yield stress behaviour. The apparent viscosity and yield stress of sludge mixtures prepared at the same total solids concentration was influenced by the interactions within the digested sludge and increased with the volume fraction of digested sludge - highlighted using shear compliance and shear modulus of sludge mixtures. However, when a thickened primary - secondary sludge mixture was mixed with dilute digested sludge, the apparent viscosity and yield stress decreased with increasing the volume fraction of digested sludge. This was caused by the dilution effect leading to a reduction in the hydrodynamic and non-hydrodynamic interactions when dilute digested sludge was added. Correlations were developed to predict the apparent viscosity and yield stress of the mixtures as a function of the digested sludge volume fraction and total solids concentration of the mixtures. The parameters of correlations can be estimated using pH of sludge. The shear and complex modulus were also modelled and they followed an exponential relationship with increasing digested sludge volume fraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. New high-speed line Nuremberg - Ingolstadt - Electrical engineering equipment; Neubaustrecke (NBS) Nuernberg - Ingolstadt - Technische Ausruestung

    Energy Technology Data Exchange (ETDEWEB)

    Krems, S. [Balfour Beatty Rail GmbH, Berlin (Germany); Matthes, U. [DB Projektbau GmbH, Nuernberg (Germany)


    The Bavarian fast railway line Nuremberg - Ingolstadt is equipped with most recent railway infrastructure for a 300 km/h fast high-speed traffic. The electrical engineering installations were implemented within a seven years period. Since December 2006 the line has been integrated into scheduled services and operated with high-speed trains. So far, the installations complied fully with all the requirements. (orig.)

  19. Phosphorus removal characteristics of granular and flocculent sludge in SBR. (United States)

    Li, Xing; Gao, Dawen; Liang, Hong; Liu, Lin; Fu, Yuan


    Aerobic granulation technology has become a novel biotechnology for wastewater treatment. However, the distinct properties and characteristics of phosphorus removal between granules and flocculent sludge are still sparse in enhanced biological phosphorus removal process. Two identical sequencing batch reactors (SBRs) were operated to compare phosphorus removal performance with granular sludge (R1) and flocculate activated sludge (R2). Results indicated that the start-up period was shorter in R2 than R1 for phosphorus removal, which made R2 reach the steady-state condition on day 21, while R1 was on day 25, and R2 released and took up more phosphorus than R1. As a result, the phosphorus removal was around 90% in R2 while 80% in R1 at the steady-state system. The special phosphorus release rate and special phosphorus uptake rate were 8.818 mg P/g volatile suspended solids (VSS)/h and 9.921 mg P/g VSS/h in R2, which were consistently greater than those (0.999 and 3.016 mg P/g VSS/h) in R1. The chemical oxygen demand removal in two reactors was similar. The granular SBR had better solid-separation performance and higher removal efficiency of NH (4) (+) -N than flocculent SBR. Denaturing gradient gel electrophoresis of PCR-amplified 16S rDNA fragment analysis revealed that the diversity and the level of phosphorus-accumulating bacteria in flocculent sludge were much more than those in the granular sludge.

  20. Co-pyrolysis of sewage sludge and manure. (United States)

    Ruiz-Gómez, Nadia; Quispe, Violeta; Ábrego, Javier; Atienza-Martínez, María; Murillo, María Benita; Gea, Gloria


    The management and valorization of residual organic matter, such as sewage sludge and manure, is gaining interest because of the increasing volume of these residues, their localized generation and the related problems. The anaerobic digestion of mixtures of sewage sludge and manure could be performed due to the similarities between both residues. The purpose of this study is to evaluate the feasibility of the co-pyrolysis of sewage sludge (SS) and digested manure (DM) as a potential management technology for these residues. Pyrolysis of a sewage sludge/manure blend (50:50%) was performed at 525°C in a stirred batch reactor under N2 atmosphere. The product yields and some characteristics of the product were analyzed and compared to the results obtained in the pyrolysis of pure residues. Potential synergetic and antagonist effects during the co-pyrolysis process were evaluated. Although sewage sludge and manure seem similar in nature, there are differences in their pyrolysis product properties and distribution due to their distinct ash and organic matter composition. For the co-pyrolysis of SS and DM, the product yields did not show noticeable synergistic effects with the exception of the yields of organic compounds, being slightly higher than the predicted average, and the H2 yield, being lower than expected. Co-pyrolysis of SS and DM could be a feasible management alternative for these residues in locations where both residues are generated, since the benefits and the drawbacks of the co-pyrolysis are similar to those of the pyrolysis of each residue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Recommendation of ruthenium source for sludge batch flowsheet studies

    Energy Technology Data Exchange (ETDEWEB)

    Woodham, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate, conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.

  2. Sewage sludge - arisings, composition, disposal capacities; Klaerschlamm - Mengen, Zusammensetzung, Entsorgungskapazitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Faulstich, M.; Rabus, J. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft; Urban, A.I.; Friedel, M. [Kassel Univ. (Gesamthochschule) (Germany). Fachgebiet Abfalltechnik


    One of the main disposal paths for sewage sludge in the past was landfilling. This option was severely restricted by the issue of the Technical Code on Household Waste in 1993. In its agricultural applications sewage sludge serves as a fertiliser and a soil improvement agent. Estimates on potential thermal treatment capacities have shown that there are enough public power plants to accommodate and provide thermal treatment for the total of sewage sludge arisings in Germany. As can be seen from the estimates presented in this paper, it would not even be necessary to restrict oneself to public power plant capacities. The paper points out possibilities of using plant capacities already existing in industrial firing plants and certain production sectors. It uses a comparison to show that sewage sludge would have to be dried in order to permit its thermal treatment in these private facilities. Aside from this, there are a number of new techniques entering the market which from the technical viewpoint also appear to be well suited for thermal sewage sludge treatment. [Deutsch] Ein wesentlicher Entsorgungsweg von Klaerschlamm war in der Vergangenheit die Verbringung auf eine Deponie. Diese Moeglichkeit ist durch die TA Siedlungsabfall von 1993 stark eingeschraenkt. Bei der landwirtschaftlichen Verwertung wird durch den Klaerschlamm eine Duengewirkung sowie eine Bodenverbesserung erreicht. Eine Abschaetzung der potentiellen thermischen Behandlungskapazitaeten zeigt, dass die gesamte bundesdeutsche Klaerschlammenge in oeffentlichen Kraftwerken unterzubringen und thermisch zu behandeln waere. Wie die hier dargestellten Abschaetzungen gezeigt haben, ist man durchaus nicht allein auf die Nutzung oeffentlicher Kraftwerkskapazitaeten angewiesen. Es wurden Moeglichkeiten zur Nutzung vorhandener Anlagenkapazitaeten in industriellen Feuerungsanlagen und in Produktionsbereichen aufgezeigt. Wie aus einem Vergleich erkennbar wird, ist allerdings eine Trocknung der Klaerschlaemme

  3. Membrane bioreactor sludge rheology at different solid retention times. (United States)

    Laera, G; Giordano, C; Pollice, A; Saturno, D; Mininni, G


    Rheological characterization is of crucial importance in sludge management both in terms of biomass dewatering and stabilization properties and in terms of design parameters for sludge handling operations. The sludge retention time (SRT) has a significant influence on biomass properties in biological wastewater treatment systems and in particular in membrane bioreactors (MBRs). The aim of this work is to compare the rheological behaviour of the biomass in a MBR operated under different SRTs. A bench-scale MBR was operated for 4 years under the same conditions except for the SRT, which ranged from 20 days to complete sludge retention. The rheological properties were measured over time and the apparent viscosity was correlated with the concentration of solid material when equilibrium conditions were reached and maintained. The three models most commonly adopted for rheological simulations were evaluated and compared in terms of their parameters. Then, steady-state average values of these parameters were related to the equilibrium biomass concentration (MLSS). The models were tested to select the one better fitting the experimental data in terms of mean root square error (MRSE). The relationship between the apparent viscosity and the shear rate, as a function of solid concentration, was determined and is proposed here. Statistical analysis showed that, in general, the Bingham model provided slightly better results than the Ostwald one. However, considering that a strong correlation between the two parameters of the Ostwald model was found for all the SRTs tested, both in the transient growth phases and under steady-state conditions, this model might be used more conveniently. This feature suggests that the latter model is easier to be used for the determination of the sludge apparent viscosity.

  4. Thermal activation of an industrial sludge for a possible valorization

    Directory of Open Access Journals (Sweden)

    Lamrani Sanae


    Full Text Available This work fits within the framework of sustainable management of sludge generated from wastewater treatment in industrial network. The studied sludge comes from an industry manufacturing sanitary ware products.Physico-chemical and mineralogical characterization was performed to give an identity card to the sludge. We noted the absence of metal pollution.The industrial sludge has been subjected to thermal activation at various temperatures (650°C to 850°C. The pozzolanic activity was evaluated by physico- chemical and mechanical methods [1]. Pozzolanicity measurement was carried out based on Chapelle test and conductivity revealed the existence of pozzolanic properties of the calcined samples. The best pozzolanic reactivity was obtained for the sample calcined at 800°C. We noticed a decrease in the reactivity of the sample calcined at 850°C. In addition, analysis by means of X-ray diffraction and Fourier transform infrared spectroscopy showed that sludge recrystallization begins at a temperature of 850°C. Pozzolanicity index of the thermally treated samples was determined by measuring the mechanical resistance of mortar specimens previously kept in a saturated lime solution for 28 days (ASTM C618 [2]. The best pozzolanic activity index was obtained for the sample calcined at 800°C (109.1%.This work is a contribution to the research for new supplying sources of raw materials and additives in the field of construction. It presents a proposition of a promising solution for the valorization of waste material as an additive instead of being discharged into open air dumps causing a major environmental problem.

  5. Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic–Anoxic–Aerobic Activated Sludge System (United States)

    Zeng, Qingling; Li, Yongmei; Yang, Shijia


    Abstract Estrogen in wastewater are responsible for a significant part of the endocrine-disrupting effects observed in the aquatic environment. The effect of sludge retention time (SRT) on the removal and fate of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic–anoxic–oxic activated sludge system designed for nutrient removal was investigated by laboratory-scale experiments using synthetic wastewater. With a hydraulic retention time of 8 h, when SRT ranged 10–25 days, E2 was almost completely removed from water, and EE2 removal efficiency was 65%–81%. Both estrogens were easily sorbed onto activated sludge. Distribution coefficients (Kd) of estrogens on anaerobic sludge were greater than those on anoxic and aerobic sludges. Mass balance calculation indicated that 99% of influent E2 was degraded by the activated sludge process, and 1% remained in excess sludge; of influent EE2, 62.0%–80.1% was biodegraded; 18.9%–34.7% was released in effluent; and 0.88%–3.31% remained in excess sludge. Optimal SRT was 20 days for both estrogen and nutrient removal. E2 was almost completely degraded, and EE2 was only partly degraded in the activated sludge process. Residual estrogen on excess sludge must be considered in the sludge treatment and disposal processes. The originality of the work is that removal of nutrients and estrogens were linked, and optimal SRT for both estrogen and nutrient removal in an enhanced biological phosphorus removal system was determined. This has an important implication for the design and operation of full-scale wastewater treatment plants. PMID:23633892

  6. Anaerobic digestion of sewage sludge with grease trap sludge and municipal solid waste as co-substrates. (United States)

    Grosser, A; Neczaj, E; Singh, B R; Almås, Å R; Brattebø, H; Kacprzak, M


    The feasibility of simultaneous treatment of multiple wastes via co-digestion was studied in semi-continuous mode at mesophilic conditions. The obtained results indicated that sewage sludge, organic fraction of municipal waste (OFMSW) and grease trap sludge (GTS) possess complementary properties that can be combined for successful anaerobic digestion. During the co-digestion period, methane yield and VS removal were significantly higher in comparison to digestion of sewage sludge alone. Addition of GTS to digesters treating sewage sludge resulted in increased VS removal and methane yield up to 13% (from 50 to 56.4) and 52% (from 300 to 456,547m(3)/Mg VSadd), respectively. While the use of OFMSW as the next co-substrate in the feedstock, can boost methane yield and VS removal up to 82% (300-547m(3)/Mg VSadd) and approximately 29% (from 50% to 64.7%), respectively. Moreover, the results of the present laboratory study revealed that the addition of co-substrates to the feedstock had a significant influence on biogas composition. During the experiment methane content in biogas ranged from 67% to 69%. While, the concentration of LCFAs was increasing with the gradual increase in the share of co-substrates in the mixtures, wherein only the oleic acid was higher than some inhibition concentrations which have been reported in the literature. However, it did not significantly affect the efficiency of the co-digestion process. Copyright © 2017. Published by Elsevier Inc.

  7. Energy recovery from wastewater treatment plants through sludge anaerobic digestion: effect of low-organic-content sludge. (United States)

    Zhang, Yuyao; Li, Huan


    During anaerobic digestion, low-organic-content sludge sometimes is used as feedstock, resulting in deteriorated digestion performance. The operational experience of conventional anaerobic digestion cannot be applied to this situation. To investigate the feature of low-organic-content sludge digestion and explain its intrinsic mechanism, batch experiments were conducted using designed feedstock having volatile solids (VS) contents that were 30-64% of total solids (TS). The results showed that the accumulative biogas yield declined proportionally from 173.7 to 64.8 ml/g VS added and organic removal rate decreased from 34.8 to 11.8% with decreasing VS/TS in the substrate. The oligotrophic environment resulting from low-organic-content substrates led to decreased microbial activity and a switch from butyric fermentation to propionic fermentation. A first-order model described the biogas production from the batch experiments very well, and the degradation coefficient decreased from 0.159 to 0.069 day-1, exhibiting a positive relation with organic content in substrate. The results observed here corroborated with data from published literature on anaerobic digestion of low-organic-content sludge and showed that it may not be feasible to recover energy from sludge with an organic content lower than 50% through mono digestion.


    Directory of Open Access Journals (Sweden)



    Full Text Available An activated sludge aeration tank and a sedimentation basin were used to treat Amol’s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d−1, respectively. The hydraulic retention times (HRT were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.

  9. Strength Measurements of Archive K Basin Sludge Using a Soil Penetrometer

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Chenault, Jeffrey W.


    Spent fuel radioactive sludge present in the K East and K West spent nuclear fuel storage basins now resides in the KW Basin in six large underwater engineered containers. The sludge will be dispositioned in two phases under the Sludge Treatment Project: (1) hydraulic retrieval into sludge transport and storage containers (STSCs) and transport to interim storage in Central Plateau and (2) retrieval from the STSCs, treatment, and packaging for shipment to the Waste Isolation Pilot Plant. In the years the STSCs are stored, sludge strength is expected to increase through chemical reaction, intergrowth of sludge crystals, and compaction and dewatering by settling. Increased sludge strength can impact the type and operation of the retrieval equipment needed prior to final sludge treatment and packaging. It is important to determine whether water jetting, planned for sludge retrieval from STSCs, will be effective. Shear strength is a property known to correlate with the effectiveness of water jetting. Accordingly, the unconfined compressive strengths (UCS) of archive K Basin sludge samples and sludge blends were measured using a pocket penetrometer modified for hot cell use. Based on known correlations, UCS values can be converted to shear strengths. Twenty-six sludge samples, stored in hot cells for a number of years since last being disturbed, were identified as potential candidates for UCS measurement and valid UCS measurements were made for twelve, each of which was found as moist or water-immersed solids at least 1/2-inch deep. Ten of the twelve samples were relatively weak, having consistencies described as 'very soft' to 'soft'. Two of the twelve samples, KE Pit and KC-4 P250, were strong with 'very stiff' and 'stiff' consistencies described, respectively, as 'can be indented by a thumb nail' or 'can be indented by thumb'. Both of these sludge samples are composites collected from KE Basin floor and

  10. Using cement, lignite fly ash and baghouse filter waste for solidification of chromium electroplating treatment sludge

    Directory of Open Access Journals (Sweden)

    Wantawin, C.


    Full Text Available The objective of the study is to use baghouse filter waste as a binder mixed with cement and lignite fly ash to solidify sludge from chromium electroplating wastewater treatment. To save cost of solidification, reducing cement in binder and increasing sludge in the cube were focused on. Minimum percent cement in binder of 20 for solidification of chromium sludge was found when controlling lignite fly ash to baghouse filter waste at the ratio of 30:70, sludge to binder ratio of 0.5, water to mixer ratio of 0.3 and curing time of 7 days. Increase of sludge to binder ratio from 0.5 to 0.75 and 1 resulted in increase in the minimum percent cement in binder up to 30 percent in both ratios. With the minimum percent cement in binder, the calculated cement to sludge ratios for samples with sludge to binder ratios of 0.5, 0.75 and 1 were 0.4, 0.4 and 0.3 respectively. Leaching chromium and compressive strength of the samples with these ratios could achieve the solidified waste standard by the Ministry of Industry. For solidification of chromium sludge at sludge to binder ratio of 1, the lowest cost binder ratio of cement to lignite fly ash and baghouse filter waste in this study was 30:21:49. The cost of binder in this ratio was 718 baht per ton dry sludge.

  11. A review of secondary sludge reduction technologies for the pulp and paper industry. (United States)

    Mahmood, Talat; Elliott, Allan


    The broader application of the activated sludge process in pulp and paper mills, together with increased production, have amplified sludge management problems. With sludge management costs as high as 60% of the total wastewater treatment plant operating costs, and increasingly stringent environmental regulations, it is economically advantageous for pulp and paper mills to reduce their biosolids production. In order to provide a state-of-the-art review of secondary sludge reduction technologies, we have considered the scenarios of lower sludge production through process modifications, and waste-activated sludge reduction through post-treatment. A critical evaluation of all candidate reduction technologies indicates that sludge reduction through treatment process changes appears more appealing than post-treatment alternatives. The former approach offers a clear advantage over the latter in that the treatment process changes reduce sludge production in the first place, thus decreasing sludge management cost. Although it is technically feasible to eliminate the need for sludge disposal, it is unlikely to be economically feasible at this time.

  12. Characteristics of KE Basin Sludge Samples Archived in the RPL - 2007

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Chenault, Jeffrey W.


    Samples of sludge were collected from the K East fuel storage basin (KE Basin) floor, contiguous pits (Weasel Pit, North Load Out Pit, Dummy Elevator Pit, and Tech View Pit), and fuel storage canisters between 1995 and 2003 for chemical and radionuclide concentration analysis, physical property determination, and chemical process testing work. Because of the value of the sludge in this testing and because of the cost of obtaining additional fresh samples, an ongoing program of sludge preservation has taken place with the goals to track the sludge identities and preserve, as well as possible, the sludge composition by keeping the sludge in sealed jars and maintaining water coverage on the sludge consistent with the controlling Fluor Hanford (FH) Sampling and Analysis plans and FH contracts with the Pacific Northwest National Laboratory (PNNL). This work was originally initiated to provide material for planned hydrothermal treatment testing in accordance with the test plan for the Sludge Treatment Project (STP) corrosion process chemistry follow on testing (Delegard et al. 2007). Although most of the planned hydrothermal testing was canceled in July 2007 (as described in the forward of Delegard et al. 2007), sample consolidation and characterization was continued to identify a set of well-characterized sludge samples that are suited to support evolving STP initiatives. The work described in the letter was performed by the PNNL under the direction of the Sludge Treatment Project, managed by Fluor Hanford.

  13. Study on cement mortar and concrete made with sewage sludge ash. (United States)

    Chang, F C; Lin, J D; Tsai, C C; Wang, K S


    This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

  14. Enhanced dewaterability of sludge during anaerobic digestion with thermal hydrolysis pretreatment: New insights through structure evolution. (United States)

    Zhang, Jingsi; Li, Ning; Dai, Xiaohu; Tao, Wenquan; Jenkinson, Ian R; Li, Zhuo


    Comprehensive insights into the sludge digestate dewaterability were gained through porous network structure of sludge. We measured the evolution of digestate dewaterability, represented by the solid content of centrifugally dewatered cake, in high-solids sequencing batch digesters with and without thermal hydrolysis pretreatment (THP). The results show that the dewaterability of the sludge after digestion was improved by 3.5% (±0.5%) for unpretreated sludge and 5.1% (±0.4%) for thermally hydrolyzed sludge. Compared to the unpretreated sludge digestate, thermal hydrolysis pretreatment eventually resulted in an improvement of dewaterability by 4.6% (±0.5%). Smaller particle size and larger surface area of sludge were induced by thermal hydrolysis and anaerobic digestion treatments. The structure strength and compactness of sludge, represented by elastic modulus and fractal dimension respectively, decreased with increase of digestion time. The porous network structure was broken up by thermal hydrolysis pretreatment and was further weakened during anaerobic digestion, which correspondingly improved the dewaterability of digestates. The logarithm of elastic modulus increased linearly with fractal dimension regardless of the pretreatment. Both fractal dimension and elastic modulus showed linear relationship with dewaterability. The rheological characterization combined with the analysis of fractal dimension of sewage sludge porous network structure was found applicable in quantitative evaluation of sludge dewaterability, which depended positively on both thermal hydrolysis and anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Risk assessments of polybrominated diphenyl ethers (PBDEs) during sludge application in China (United States)

    Qian, Jun


    Due to increasingly less space in municipal environment, waste management has become an urgent issue worldwide. As one of common municipal waste, sewage sludge from wastewater treatment plants (WWTPs) contains abundant nutrients, some of which can be quite essential for plant growth. In consideration of nutrient recycling and energy saving, sludge application has been frequently promoted in many countries across the world. However, even after several sludge stabilization procedures, sewage sludge may still contain a large variety of toxic pollutants, especially some emerging organic contaminants (EOCs). Applied in various household products and plastic industries as additives, polybrominated diphenyl ethers (PBDEs) have been constantly detected in sewage sludge samples from several cities in China since 2005, as well as some biosolid samples after sludge stabilization processes, suggesting their strong persistence and wide occurrence. During sludge application onto farmland soils, PBDEs may desorb from sludge particles and get attached by soil organic matter (SOM), followed by plant root uptake and translocation to aboveground tissues. In this study, data about current pollution of PBDEs in sewage sludge samples from China was reviewed, and the potential risks during sludge application was comprehensively assessed.


    Directory of Open Access Journals (Sweden)

    Magdalena Filkiewicz


    Full Text Available According to the National Waste Management Plan 2014 (NWMP 2014 recommended method of utilization of sewage sludge is using it for agricultural purposes or for land reclamation. The sludge is characterized by a high content of organic substances, microelements and biogenic compounds, through which sewage sludge possess high soil formation and fertilization properties. It is assumed that in 2020 approximately 30% of the sludge production will be used for agricultural purposes, while 15% will be used for land reclamation. We have to remember that prior to the introduction of sludge into the ground, security, health and chemical requirements should be met. In order to use the sludge for agricultural purposes, the process of their disposal should be previously carried out e.g. Autoheated Thermophilic Aerobic Digestion (ATAD. It allows for hygienisation of sewage sludge and reducing the heavy metal content. As a result, processed sewage sludge is characterized by the presence of heavy metals in amounts which do not exceed the standards. It is also deprived of microorganisms. The stabilized sludge is characterized by high phosphorus and calcium content. Therefore there is possibility to use the examined sludge in agriculture.

  17. Optimal sludge retention time for a bench scale MBR treating municipal sewage. (United States)

    Pollice, A; Laera, G; Saturno, D; Giordano, C; Sandulli, R


    Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.

  18. Predicting the drying properties of sludge based on hydrothermal treatment under subcritical conditions. (United States)

    Mäkelä, Mikko; Fraikin, Laurent; Léonard, Angélique; Benavente, Verónica; Fullana, Andrés


    The effects of hydrothermal treatment on the drying properties of sludge were determined. Sludge was hydrothermally treated at 180-260 °C for 0.5-5 h using NaOH and HCl as additives to influence reaction conditions. Untreated sludge and attained hydrochar samples were then dried under identical conditions with a laboratory microdryer and an X-ray microtomograph was used to follow changes in sample dimensions. The effective moisture diffusivities of sludge and hydrochar samples were determined and the effect of process conditions on respective mean diffusivities evaluated using multiple linear regression. Based on the results the drying time of untreated sludge decreased from approximately 80 min to 37-59 min for sludge hydrochar. Drying of untreated sludge was governed by the falling rate period where drying flux decreased continuously as a function of sludge moisture content due to heat and mass transfer limitations and sample shrinkage. Hydrothermal treatment increased the drying flux of sludge hydrochar and decreased the effect of internal heat and mass transfer limitations and sample shrinkage especially at higher treatment temperatures. The determined effective moisture diffusivities of sludge and hydrochar increased as a function of decreasing moisture content and the mean diffusivity of untreated sludge (8.56·10(-9) m(2) s(-1)) and sludge hydrochar (12.7-27.5·10(-9) m(2) s(-1)) were found statistically different. The attained regression model indicated that treatment temperature governed the mean diffusivity of hydrochar, as the effects of NaOH and HCl were statistically insignificant. The attained results enabled prediction of sludge drying properties through mean moisture diffusivity based on hydrothermal treatment conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carlos J.; Reeve, Petra J.; Sawade, Emma [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Voldoire, Camille F. [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Newton, Kelly; Praptiwi, Radisti [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Collingnon, Lea [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Dreyfus, Jennifer [Allwater, Adelaide Services Alliance, Wakefield St, Adelaide, SA 5001 (Australia); Hobson, Peter [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Gaget, Virginie [University of Adelaide, Ecology and Environmental Sciences, School of Biological Sciences, Adelaide, SA 5005 (Australia); Newcombe, Gayle, E-mail: [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia)


    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10 days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. - Highlights: • Cyanobacteria in water treatment sludge significantly impact supernatant quality • Cyanobacteria can survive, and thrive, in sludge lagoon supernatant and in treatment sludge • Metabolite concentrations in cyanobacteria in sludge can increase up to 500% • The risk associated with supernatant recycling was assessed relative to available treatment barriers.

  20. Combination of alkaline and microwave pretreatment for disintegration of meat processing wastewater sludge. (United States)

    Erden, G


    Meat processing wastewater sludge has high organic content but it is very slow to degrade in biological processes. Anaerobic digestion may be a good alternative for this type of sludge when the hydrolysis, known to be the rate-limiting step of biological sludge anaerobic degradation, could be eliminated by disintegration. This investigation deals with disintegration of meat processing wastewater sludge. Microwave (MW) irradiation and combined alkaline pretreatment and MW irradiation were applied to sludge for disintegration purposes. Disintegration performance of the methods was evaluated with disintegration degree based on total and dissolved organic carbon calculations (DD(TOC)), and the solubilization of volatile solids (S(VS)) in the pretreated sludge. Optimum conditions were found to be 140 degrees C and 30 min for MW irradiation using response surface methodology (RSM) and pH = 13 for combined pretreatment. While DD(TOC) was observed as 24.6% and 54.9, S(VS) was determined as 8.54% and 42.5% for MW pretreated and combined pretreated sludge, respectively. The results clearly show that pre-conditioning of sludge with alkaline pretreatment played an important role in enhancing the disintegration efficiency of subsequent MW irradiation. Disintegration methods also affected the anaerobic biodegradability and dewaterability of sludge. An increase of 23.6% in biogas production in MW irradiated sludge was obtained, comparing to the raw sludge at the end of the 35 days of incubation. This increase was observed as 44.5% combined pretreatment application. While MW pretreatment led to a little improvement of the dewatering performance of sludge, in combined pretreatment NaOH deteriorates the sludge dewaterability.