WorldWideScience

Sample records for plating line sludges

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

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben

    1997-01-01

    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...

  2. In-line rheological characterisation of wastewater sludges using non ...

    African Journals Online (AJOL)

    2015-10-05

    Oct 5, 2015 ... capabilities of the in-line ultrasound technique for different viscosities and fluid properties. ... Tube viscometry offers the possibility of in-line rheological ..... curvature at shear rates lower than 200 s-1 indicates that the sludges ...

  3. Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

    Science.gov (United States)

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2006-11-02

    The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

  4. Design of convex hull plate forming by pure line heating

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-biao; JI Zhuo-shang; LIU Yu-jun

    2004-01-01

    This paper presents a ship-hull plate forming way by pure line heating. The heating lines forming the required bending angle is determined by curvature analysis method. Heating along the calculated heating lines results in bland plate with initial transverse curvature. Then, the plate with desired convex shape can be obtained by heating in the longitudinal edge. This is the whole forming process by pure line heating. This paper presents a method of plane development for ship-hull plate with B-spline surface representation, and provides the shrinkage heating lines in the forming process. This forming way would facilitate temperature control and make plate forming automatically easy.

  5. A Novel Separation Method of Microthrix parvicella Filaments from Activated Sludge by a Hydrophobic Plate.

    Science.gov (United States)

    Fei, Xuening; Li, Songya; Cao, Lingyun; Yan, Weiguo; Ma, Huaji; Jia, Guozhi

    2015-10-01

    The aim of this paper is to develop a novel method to separate Microthrix parvicella (M. parvicella) filaments from activated sludge easily and quickly, as there are a few difficulties in the isolation of M. parvicella filaments, such as complicated isolation process, time consuming, etc. In this work, a series of hydrophobic plate with and without microchannels have been prepared for the separation of M. parvicella filaments. The results showed that the presence of microchannels and hydrophobic property of the hydrophobic plates affected the separation efficiency of M. parvicella significantly. The scanning electron microscope and Keyence Digital Microscope analysis results showed that the diameter of microchannels was similar to the width of M. parvicella filament, which was beneficial for the fastening of M. parvicella filaments on the plate. The hydrophobic property of the prepared plates was tested by contact angle of water droplets, and the results displayed that the polydimethylsiloxane (PDMS) plate possessed the highest contact angle compared with that of other plates, like polymethylmethacrylate, polystyrene plate, and PDMS plate with no hydrophobic microchannels. Thus, it was concluded that the high separation efficiency of PDMS plates to M. parvicella filaments was due to its best hydrophobic property.

  6. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  7. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  8. Slab Tracking and Controlling on Hot Plate Rolling Line

    Institute of Scientific and Technical Information of China (English)

    姚小兰; 邓波; 梁启宏; 李保奎

    2004-01-01

    By studying the slab moving in detail in the plate rolling process, the problem of slab tracking and controlling was solved by using the distributed control system. The problems of rhythm control for the big-complex system, the exchange of manual and automatic operations, the data exchange between the levelⅠ, TCS (technology control system) and levelⅡ, PCS (process control system), are solved. By this way, the automatic level of the plate production line is improved.

  9. Optimisation of sludge line management to enhance phosphorus recovery in WWTP.

    Science.gov (United States)

    Marti, N; Ferrer, J; Seco, A; Bouzas, A

    2008-11-01

    The management of the sludge treatment line can be optimized to reduce uncontrolled phosphorus precipitation in the anaerobic digester and to enhance phosphorus recovery in WWTP. In this paper, four operational strategies, which are based on the handling of the prefermented primary sludge and the secondary sludge from an EBPR process, have been tested in a pilot plant. The separated or mixed sludge thickening, the use of a stirred contact tank and the elutriation of the thickened sludge are the main strategies studied. Both the reduction of phosphorus precipitation in the digester and the supernatant suitability for a struvite crystallization process were assessed in each configuration. The mixed sludge thickening combined with a high flowrate elutriation stream reduced the phosphorus precipitation in the digester by 46%, with respect to the separate sludge thickening configuration (common practice in WWTP). Moreover, in this configuration, 68% of the soluble phosphorus in the system is available for a possible phosphorus recovery process by crystallization (not studied in this work). However, a high Ca/P molar ratio was detected in the resultant supernatant which is pointed out as a problem for the efficiency of struvite crystallization.

  10. OPTIMIZATION OF TRANSIENT FEEDING TO PARALLEL-PLATE TRANSMISSION LINES FROM COAXIAL LINE

    Institute of Scientific and Technical Information of China (English)

    Tian Chunming; Wang Jianguo; Meng Fenxia; Zhang Maoyu; Ge Debiao

    2001-01-01

    The transient feeding to parallel-plate transmission lines from coaxial line is optimized by using the Finite-Difference Time-Domain (FDTD) method and a simple FDTD feed model. Observing the reflected voltages, this letter presents the optimal feeding position and ratio of width to height for a given input impedance of the coaxial line.

  11. New Method for Hard Sludge Removal from Tube Plate Surfaces: The AREVA Enhanced Inner Bundle Lancing Process

    Energy Technology Data Exchange (ETDEWEB)

    Stoss, J.; Santibanez, M.

    2014-07-01

    AREVA is currently conducting the final steps to start-up an enhanced technology to remove hard sludge deposits from the inner bundle area of the tube sheets. This inner bundle area at the top of the tube plate is the location with the lowest flow velocity of the circulating water at the secondary closed loop. The reduced water speed causes increased accumulation of ferrite oxides at these locations. (Author)

  12. Cr and Ni recovery during bioleaching of dewatered metal-plating sludge using Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Rastegar, S O; Mousavi, S M; Shojaosadati, S A

    2014-09-01

    This study determined the optimal conditions required to attain maximum metal recovery in the bioleaching process of dewatered metal-plating sludge using Acidithiobacillus ferrooxidans (A. ferrooxidans). Adaptation of this strain was carried up to 1% (w/v) of the sample. Three factors including initial pH, initial Fe(3+) concentration and pulp density were selected as the effective factors and were optimized using a central composite design of response surface methodology. An initial pH of 1, pulp density of 9 g/l and initial Fe(3+) concentration of 1g/l were determined to be optimum values by the statistical models. The highest extractions for Cr and Ni under optimal conditions were 55.6% and 58.2%, respectively. Bioleaching kinetics was investigated using a modified shrinking core model to better understand the mechanism of the leaching reaction. The model predictions indicate that the diffusion step controlled the overall dissolution kinetics and is the rate controlling step.

  13. Numerical Methods for Plate Forming by Line Heating

    DEFF Research Database (Denmark)

    Clausen, Henrik Bisgaard

    2000-01-01

    Line heating is the process of forming originally flat plates into a desired shape by means of heat treatment. Parameter studies are carried out on a finite element model to provide knowledge of how the process behaves with varying heating conditions. For verification purposes, experiments are ca...... are carried out; one set of experiments investigates the actual heat flux distribution from a gas torch and another verifies the validty of the FE calculations. Finally, a method to predict the heating pattern is described....

  14. Vibration Analysis of Composite Rectangular Plates Reinforced along Curved Lines

    Science.gov (United States)

    Honda, Shinya; Oonishi, Yoshimasa; Narita, Yoshihiro; Sasaki, Katsuhiko

    In the past few decades, composite materials composed of straight fibers and polymer matrix have gained their status as the most promising material for light-weight structures. Technical merit of the composites as tailored material also provided practical advantages in the optimum design process. Recently, it is reported that the fabrication machine has been developed to make curved fibers embedded in the matrix material. Based on such technical advancement, this paper proposes an analytical method to study vibration of composite rectangular plates reinforced along curved lines. The approach is based on the Ritz method where variable fiber direction can be accommodated. For this purpose, the fibers continuously changing their direction are formulated as the variable bending stiffness in the total potential energy. A frequency equation is derived by the Ritz minimizing process, and frequency parameters are calculated as the eigenvlaues in the eigenvalue problem. In numerical results, the accuracy of the method is presented by comparing present results with FEM results. The advantages of present plate are confirmed by comparing natural frequencies and mode shapes with those of conventional composite and isotropic plates, and the effectiveness of the new solution to the most recent problem is demonstrated.

  15. Performance of lime-BHA solidified plating sludge in the presence of Na2SiO3 and Na2CO3.

    Science.gov (United States)

    Piyapanuwat, Rungroj; Asavapisit, Suwimol

    2011-09-01

    This research investigated the performance of lime-BHA (black rice husk ash) solidified plating sludge with 2 wt% NaO from Na(2)SiO(3) and Na(2)CO(3) at the level of 0, 30 and 50 wt%. The sludge was evaluated for strength development, leachability, solution chemistry and microstructure. The lime-BHA solidified plating sludge with Na(2)SiO(3) and Na(2)CO(3) had higher early strength when compared to the control. The addition of Na(2)SiO(3) and Na(2)CO(3) increased the OH(-) concentration and decreased the Ca(2+) and heavy metal ions in solution after the first minute. The XRD patterns showed that the addition of Na(2)SiO(3) resulted in the formation of calcium silicate hydrates, while the addition of Na(2)CO(3) resulted in CaCO(3). The heavy metals from the plating sludge, especially Zn, were immobilized in calcium zincate and calcium zinc silicate forms for the lime-BHA with and without Na(2)SiO(3) solidified wastes, while samples with Na(2)CO(3) contained Zn that was fixed in the form of CaZnCO(3). The cumulative leaching of Fe, Cr and Zn from the lime-BHA solidified plating sludge decreased significantly when activators were added, especially Na(2)CO(3).

  16. Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge.

    Science.gov (United States)

    Bayat, Belgin; Sari, Bulent

    2010-02-15

    The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25+/-2 degrees C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25+/-2 degrees C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching>ferric chloride leaching>sulfuric acid

  17. On-line determination of sludge settling velocity for flux-based real-time control of secondary clarifiers.

    Science.gov (United States)

    Lynggaard-Jensen, A; Lading, L

    2006-01-01

    The state diagram for operation of secondary clarifiers is used to design a control algorithm for the return sludge pumping and determination of the actual hydraulic capacity of the biological step of a wastewater treatment plant. On-line input for the control algorithm is derived from a sludge volume sensor and a suspended solids sensor in the form of software sensors giving values for the sludge settling characteristics - settling velocity, sludge volume index, initial settling velocity and the exponent in the Vesilind equation - allowing the control to accommodate the ever changing settling characteristics and thereby keep the suspended solids flux in the clarifiers in balance for both dry weather flows and during rain events. The control algorithm has been implemented, tested and set into normal operation on a full scale wastewater treatment plant.

  18. A study of the relationship among sludge retention time, bacterial communities, and hydrolytic enzyme activities in inclined plate membrane bioreactors for the treatment of municipal wastewater.

    Science.gov (United States)

    Ittisupornrat, Suda; Tobino, Tomohiro; Yamamoto, Kazuo

    2014-11-01

    Inclined plate membrane bioreactors (ip-MBRs) have been proposed as a highly effective method in wastewater treatment. With the help of settling enhancer inclined plates, dense excess sludge can be kept in the mainstream of the process, and consequently, suitable sludge mass can be maintained in the membrane tank. In this study, the relationship among sludge retention time (SRT), bacterial communities, and hydrolytic enzyme activities was investigated. Two identical bench-scale ip-MBRs were operated 1 year in real municipal wastewater treatment. Multidimensional scaling (MDS) plots of terminal restriction fragment length polymorphism (T-RFLP) fingerprints showed similar changes in the bacterial communities in terms of bacterial members and abundance over time in both the reactors, which was primarily caused by the changes of wastewater composition. However, the impact of SRT revealed significant differences in the dominant bacterial communities when both the reactors were operated with a largely different SRT (infinite SRT and SRT of 20 days). The sequences of bacterial 16S rRNA gene were classified into six libraries of A-F. The largest group of sequences belonged to the phylum Proteobacteria. The phylum Bacteroidetes was dominant in the seed sludge retrieved from the conventional activated sludge (CAS) as Flavobacterium-like bacterium was dominantly observed. Under the MBR operation (libraries B-F), bacterial communities belonging to the phyla Proteobacteria and Chloroflexi were dominant. Most of them may be responsible for protein degradation because aminopeptidase activity increased in proportion with the abundance of these bacteria.

  19. Study on the automatic process of line heating for pillow shape plate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper focuses on the process for pillow shape plate by line heating technique, which is widely applied in the production of ship hull. Based on the analysis of primary parameters and experimental data in line heating process, the amount of local contraction generated by line heating has been illustrated. Then, combining with the computational result of local deformation determined by shell plate development, an optimization method for line heating parameters has been studied. This prediction system may provide rational arrangements of heating lines and technical parameters of process. By integrating the prediction system into the line heating robot for pillow shape plate, the automatic process of line heating for pillow shape plate can be achieved.

  20. Assessment of metabolic properties and kinetic parameters of methanogenic sludge by on-line methane production rate measurements

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Kleerebezem, R.; Lettinga, G.

    2002-01-01

    This report presents a new approach to studying the metabolic and kinetic properties of anaerobic sludge from single batch experiments. The two main features of the method are that the methane production is measured on-line with a relatively cheap system, and that the methane production data can be

  1. Nodal line optimization and its application to violin top plate design

    Science.gov (United States)

    Yu, Yonggyun; Jang, In Gwun; Kim, In Kyum; Kwak, Byung Man

    2010-10-01

    In the literature, most problems of structural vibration have been formulated to adjust a specific natural frequency: for example, to maximize the first natural frequency. In musical instruments like a violin; however, mode shapes are equally important because they are related to sound quality in the way that natural frequencies are related to the octave. The shapes of nodal lines, which represent the natural mode shapes, are generally known to have a unique feature for good violins. Among the few studies on mode shape optimization, one typical study addresses the optimization of nodal point location for reducing vibration in a one-dimensional beam structure. However, nodal line optimization, which is required in violin plate design, has not yet been considered. In this paper, the central idea of controlling the shape of the nodal lines is proposed and then applied to violin top plate design. Finite element model for a violin top plate was constructed using shell elements. Then, optimization was performed to minimize the square sum of the displacement of selected nodes located along the target nodal lines by varying the thicknesses of the top plate. We conducted nodal line optimization for the second and the fifth modes together at the same time, and the results showed that the nodal lines obtained match well with the target nodal lines. The information on plate thickness distribution from nodal line optimization would be valuable for tailored trimming of a violin top plate for the given performances.

  2. Numerical Methods for Plate Forming by Line Heating

    DEFF Research Database (Denmark)

    Clausen, Henrik Bisgaard

    2000-01-01

    Few researchers have addressed so far the topic Line Heating in the search for better control of the process. Various methods to help understanding the mechanics have been used, including beam analysis approximation, equivalent force calculation and three-dimensional finite element analysis. I...... consider here finite element methods to model the behaviour and to predict the heating paths....

  3. A License Plate Locating Method Based on Tophat-bothat Changing and Line Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Hou, P G; Zhao, J; Liu, M [Electrical Engineering Institute of Yanshan University, QinHuangdao, Hebei (China)

    2006-10-15

    The automatic license plate recognition is an important technique to obtain traffic information, it mixes computer vision, image processing techniques and pattern recognition techniques, it is an important technique in intelligent traffic system. In a vehicle license plate recognition system, plate region detection is the key step before the final recognition. This article introduces the whole process of plate region detection. Top - hat and bot - hat transformation are used for enhancing the image contrast in this paper, and wavelet threshold method is used as image filter, and a improved line scanning is used for plate region detection at last. This method has strong practicability. The experimental results demonstrate that the method introduced in this paper is effective.

  4. Free Vibrations of a Trapezoidal Plate with an Internal Line Hinge

    Directory of Open Access Journals (Sweden)

    María Virginia Quintana

    2014-01-01

    Full Text Available This paper deals with a general variational formulation for the determination of natural frequencies and mode shapes of free vibrations of laminated thin plates of trapezoidal shape with an internal line hinge restrained against rotation. The analysis was carried out by using the kinematics corresponding to the classical laminated plate theory (CLPT. The eigenvalue problem is obtained by employing a combination of the Ritz method and the Lagrange multipliers method. The domain of the plate is transformed into a rectangular domain in the computational space by using nonorthogonal triangular coordinates and the transverse displacements are approximated with a set of simple polynomials automatically generated and expressed in the triangular coordinates. The developed algorithm allows obtaining approximate analytical solutions for mentioned plate with different geometries, aspect ratio, position of the line hinge, and boundary conditions including translational and rotational elastically restrained edges. It allows studying the influence of the mentioned line on the vibration frequencies and respective mode shapes. The algorithm can easily be programmed and it is numerically stable. Additionally, as a particular case, the results of triangular plates can be easily generated.

  5. 硫脲法电镀污泥中提金研究%The Research of Gold Extraction From Plating Sludge by Thiourea

    Institute of Scientific and Technical Information of China (English)

    程进; 刘承先

    2012-01-01

    在电镀行业中金是常用的贵金属之一,提高含金污泥金的回收率一直是研究的热门。论文用酸性硫脲从电镀污泥处理后的树脂中回收金,并探讨了该方法的最佳工艺条件。结果显示,在40℃恒温搅拌条件下用FeCl3.6H2O(加入量2 g/L溶液)、硫脲(浓度1.0 g/L)的混合溶液(pH=1.5)浸取12 h,浸金率最高,可达85%。%Gold is one of the widely used precious metals in plating industry,this project is aimed to improve the recovery of the sludge containing gold.This paper is focused on gold extraction by leaching plating sludge with acidic thiourea solution.And it is indicated that:under the leaching conditions of pH=1.5,leaching temperature 40 ℃,leaching time 12 h,and 2 g FeCl3.6H2O and 10 g thiourea added per liter solution,the highest leaching rate of gold can be obtained up to 85 %.

  6. In - line determination of heat transfer coefficients in a plate heat exchanger

    Science.gov (United States)

    Sotelo, S. Silva; Domínguez, R. J. Romero

    This paper shows an in - line determination of heat transfer coefficients in a plate heat exchanger. Water and aqueous working solution of lithium bromide + ethylene glycol are considered. Heat transfer coefficients are calculated for both fluids. "Type T" thermocouples were used for monitoring the wall temperature in a plate heat exchanger, which is one of the main components in an absorption system. Commercial software Agilent HP Vee Pro 7.5 was used for monitoring the temperatures and for the determination of the heat transfer coefficients. There are not previous works for heat transfer coefficients for the working solution used in this work.

  7. Reduction of Biological Sludge Production Applying an Alternating Oxic/anoxic Process in Water Line.

    Science.gov (United States)

    Eusebi, Anna Laura; Panigutti, Maximiliano; Battistoni, Paolo

    2016-06-01

    Alternating oxic/anoxic process, applied for the main objective of the improvement of nitrogen performances, was studied in terms of secondary effect of biomass reduction. The process was carried out in one real water resource recovery facility and the data were compared with the previous conventional period when a conventional process was adopted. The main mechanism of the process for the sludge minimization is recognized in the metabolic uncoupling. In fact, an increase of the specific oxygen uptake rate in the biological reactor was recorded stimulated by the change of the oxidation reduction potential environment. Moreover, the heterotrophic growth yield was measured equal to 0.385 kgVSS/kgCOD. The global percentage of reduction was tested with the mass balance of solids. The process is able to decrease the observed sludge yield up to 20%. The specific energy consumption was evaluated.

  8. Plate acoustic waves for low frequency delay line delaying signals up to 0.5 ms

    Science.gov (United States)

    Zaitsev, B. D.; Kuznetsova, I. E.; Zemnyukov, N. E.; Proidakov, V. I.; Teplykh, A. A.

    2010-01-01

    At present time there exists the problem of development of main memory elements based on the delay of electromagnetic signal with frequency of ˜100 kHz on hundreds microseconds. This paper is devoted to theoretical and experimental investigation of the possibility of development of corresponding acoustic delay lines. It was supposed to use the antisymmetric acoustic waves of zero order propagating in thin (compared to wavelength) metal plates. In this connection, we theoretically studied the parameters of A0 waves propagating in plates of various metals such as brass, bronze, copper, steel, and aluminum. For analysis of wave propagation in aforementioned plates, we used the standard motion equation and constitutive material equation for investigated medium as well as corresponding mechanical boundary conditions. As a result, the phase and group velocities versus parameter hf (h= plate thickness, f= wave frequency) were calculated for A0 wave propagating in mentioned above plates. It has been found that for steel plate the delay time about 0.5 ms can be achieved at the lengths of waveguide L=0.373, 0.737, and 0.971 m for h=0.175, 0.5, and 1.0 mm, respectively at f=120 kHz. The theoretical results were verified by experiment, which showed the possibility of development of corresponding delay lines with delay time ˜500 mks and acceptable insertion loss. In experiments, the excitation and reception of A0 waves were performed by the standard piezoelectric transducers of longitudinal waves and prismatic steel concentrators. The details of theoretical analysis and experiment are described.

  9. The vibration and stability analysis of moderate thick plates by the method of lines

    Science.gov (United States)

    Tang, Shou-Gao; Yuan, Si

    1992-06-01

    The method of lines based on Hu Hai-chang's theory for the vibration and stability of moderate thick plates is developed. The standard nonlinear ordinary differential equation (ODE) system for natural frequencies and critical load is given by use of ODE techniques; any indicated eigenvalue could be obtained directly from ODE solver by employing the so-called initial eigenfunction technique instead of the mode orthogonality condition. Numerical examples show that the present method is very effective and reliable.

  10. Thermal Stresses in an Anisotropic Thin Plate Subjected to Moving Line Heat Sources

    Directory of Open Access Journals (Sweden)

    Malak Naji

    2014-02-01

    Full Text Available The aim of this present study is to investigate thermal stresses inside a thin anisotropic mild steal plate during moving line heat source. The parabolic heat conduction model is used for the prediction of the temperature history. The temperature distributions are determined numerically using finite difference method. Thermal stresses are computed numerically. It is found that the thermal conductivity ratio affect in both temperature and thermal stresses distributions, in additional to the speed and heat source intensity.

  11. Quantitative monitoring of an activated sludge reactor using on-line UV-visible and near-infrared spectroscopy.

    Science.gov (United States)

    Sarraguça, Mafalda C; Paulo, Ana; Alves, Madalena M; Dias, Ana M A; Lopes, João A; Ferreira, Eugénio C

    2009-10-01

    The performance of an activated sludge reactor can be significantly enhanced through use of continuous and real-time process-state monitoring, which avoids the need to sample for off-line analysis and to use chemicals. Despite the complexity associated with wastewater treatment systems, spectroscopic methods coupled with chemometric tools have been shown to be powerful tools for bioprocess monitoring and control. Once implemented and optimized, these methods are fast, nondestructive, user friendly, and most importantly, they can be implemented in situ, permitting rapid inference of the process state at any moment. In this work, UV-visible and NIR spectroscopy were used to monitor an activated sludge reactor using in situ immersion probes connected to the respective analyzers by optical fibers. During the monitoring period, disturbances to the biological system were induced to test the ability of each spectroscopic method to detect the changes in the system. Calibration models based on partial least squares (PLS) regression were developed for three key process parameters, namely chemical oxygen demand (COD), nitrate concentration (N-NO(3)(-)), and total suspended solids (TSS). For NIR, the best results were achieved for TSS, with a relative error of 14.1% and a correlation coefficient of 0.91. The UV-visible technique gave similar results for the three parameters: an error of approximately 25% and correlation coefficients of approximately 0.82 for COD and TSS and 0.87 for N-NO(3)(-) . The results obtained demonstrate that both techniques are suitable for consideration as alternative methods for monitoring and controlling wastewater treatment processes, presenting clear advantages when compared with the reference methods for wastewater treatment process qualification.

  12. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  13. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  14. Three-dimensional elasticity solution of simple-supported rectangular plate on point supports,line supports and elastic foundation

    Institute of Scientific and Technical Information of China (English)

    XU YePeng; ZHOU Ding

    2009-01-01

    This paper studies the bending of simple-supported rectangular plate on point supports, line supports and elastic foundation. On the basis of three-dimensional elasticity theory, the exact expressions of the displacement functions, which satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The reaction forces of the in-termediate supports are regarded as the unknown external forces acting on the lower surface of the plate. The unknown coefficients are then determined by the boundary conditions on the upper and lower surfaces of the plate. Comparing the numerical results obtained from the proposed method to those obtained from Kirchhoff plate theory, Mindlin plate theory and those obtained from the commer-cial finite element software ANSYS, the high accuracy of the present method has been demonstrated.

  15. Three-dimensional elasticity solution of simple-supported rectangular plate on point supports, line supports and elastic foundation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper studies the bending of simple-supported rectangular plate on point supports, line supports and elastic foundation. On the basis of three-dimensional elasticity theory, the exact expressions of the displacement functions, which satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The reaction forces of the in- termediate supports are regarded as the unknown external forces acting on the lower surface of the plate. The unknown coefficients are then determined by the boundary conditions on the upper and lower surfaces of the plate. Comparing the numerical results obtained from the proposed method to those obtained from Kirchhoff plate theory, Mindlin plate theory and those obtained from the commer- cial finite element software ANSYS, the high accuracy of the present method has been demonstrated.

  16. Three-Dimensional Numerical Simulation of Plate Forming by Line Heating

    DEFF Research Database (Denmark)

    Clausen, Henrik Bisgaard

    1999-01-01

    addressed the problem of simulating the process, and although very few have been successful in gaining accurate results valuable information about the mechanics have been derived. However, the increasing power of computers now allows for numerical simulations of the forming process using a three......-dimensional thermo-mechanical model. Although very few have been successful in gaining accurate results valuable information about the mechanics has been derived. However, the increasing power of computers now allows for numerical simulations of the forming process using a three-dimensional thermo-mechanical model.......Line Heating is the process of forming (steel) plates into shape by means of localised heating often along a line. Though any focussed heat source will do, the inexpensive and widely available oxyacettylene gas torch is commonly applied in ship production.Over the years, many researchers have...

  17. 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.

    2009-07-01

    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)

  18. Position Measurements with Micro-Channel Plates and Transmission lines using Pico-second Timing and Waveform Analysis

    CERN Document Server

    Adamsa, Bernhard; Bogdan, Mircea; Byrum, Karen; Genat, Jean-Francois C; Grabas, Herve; Frisch, Henry J; Kim, Heejong; Heintz, Mary K; Natoli, Tyler; Northrop, Richard; Oberla, Eric; Meehan, Samuel; May, Edward N; Stanek, Robert; Tang, Fukun; Varner, Gary; Yurtsev, Eugene

    2009-01-01

    The anodes of Micro-Channel Plate devices are coupled to fast transmission lines in order to reduce the number of electronics readout channels, and can provide two-dimension position measurements using two-ends delay timing. Tests with a laser and digital waveform analysis show that resolutions of a few hundreds of microns along the transmission line can be reached taking advantage of a few pico-second timing estimation. This technique is planned to be used in Micro-channel Plate devices integrating the transmission lines as anodes.

  19. Health concerns of heterotrophic plate count (HPC) bacteria in dental equipment water lines.

    Science.gov (United States)

    Allen, Martin J; Edberg, Stephen C

    2016-06-01

    There is an unsubstantiated concern as to the health relevance of HPC (heterotrophic plate count) bacteria in dental equipment waterlines. The American Dental Association (ADA) web site includes guidelines for controlling HPC populations and implies that HPC populations >500 CFU/mL as a "health" benchmark. The world-wide published literature including the United Nations fully examined this situation and concluded that HPC bacteria are not a health risk, but merely a general water quality parameter for all waters including dental water lines. This review provides documentation that the standard measurement of HPC bacteria in waters alone do not pose a health risk and the ADA already provides appropriate practices to minimize HPC bacteria in dental equipment water.

  20. The origin of the Line Islands: plate or plume controlled volcanism?

    Science.gov (United States)

    Storm, L. P.; Konter, J. G.; Koppers, A. A.

    2011-12-01

    Geochemical compositions of melts produced in the Earth's mantle provide key data for our understanding of the Earth's internal structure. Particularly, the range in compositions for oceanic intraplate volcanism has fueled the ongoing debate on the dynamic origin of hotspots. Traditionally, hotspots have been interpreted to originate from narrow, upwelling plumes of hot mantle material that reach the bottom of the tectonic plates. Progressively younger volcanoes, as seen at, for example, Hawaii, are then derived from plume melts. However, such a plume may originate from the core-mantle boundary, the top of seismically defined superplumes, or the origin may not lie in a buoyantly upwelling plume at all. The presence of an age progressive volcanic chain and a large igneous province, a high buoyancy flux, the geochemical composition of the erupted lavas, and seismically slow velocities have been used to distinguish different hotspot origins. Volcanic chains that lack most of these features may originate from the eruption of shallow melts along lithospherically controlled cracks. A unique area to study this type of volcanism is the Line Islands. These islands define a complex chain of volcanoes south of Hawaii that morphologically define multiple sub-groups. Moreover, recent age dating has revealed a complex geochronology. Combined geochronological and geochemical data from the Line Islands allude to the presence of shallow mantle melts that feed eruptions where there are weaknesses in the plates due to fractures or fissures. The Line Islands consist of elongated ridges, seamounts, atolls and islands that form the northern segment of the Line-Tuamotu chain of volcanoes. The volcanic chain is divided into three morphologically distinct regions; the northern, central and southern provinces. Long en echelon ridges of the Line Islands Cross Trend intersect the northern province at 14-16°N, which consists of the section between the Molokai and Clarion fracture zones. The

  1. Sludge Lancing IBL: results and experiences in the Spanish NPP's; Sluge Lancing e IBL: resultados y experiencias en las centrales espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Montoro, E.; Pozo, C. del

    2014-04-01

    During the operation cycle of the PWR plants, oxides deposits (sludge) generated in the secondary circuit by erosion corrosion, chemical additives, etc. Which are deposited on the tube plate of GVs, limiting their efficiency and lifespan. To reduce them, Iberdrola Engineering and Construction, together with SRA SAVAC cleaned by high-pressure water means and tele visual inspection between tubes of the GVs. After Sludge Lancing cleanings performed by 250 bar from the center line, an area of solidified sludge remaining on the tubular plate was identified. Late 2010, Iberdrola Engineering and Construction, together with SRA SAVAC developed the Inner Bundle Lancing (IBL) system, which is based on a jet of water of high pressure>500 bar directly impacting areas of hard sludge within the tube bundle to detach and break the deposits into small pieces that can be extracted from GV through a closed circuit suction. (Author)

  2. Computerized Ultrasonic System for On-Line Determination of Chromium Thickness During Plating of Tubes

    Science.gov (United States)

    1993-01-01

    Giordano, Fred Nelson, and John Askew for their cooperation during the shop plating runs; Glen Friar for his encouragement; William Korman for his usual...ATTN: DEPT FOR SCI AND TECH I ATTN: SMCRI-ENM THE PENTAGON ROCK ISLAND, IL 61299-5000 WASHINGTON, D.C. 20310-0103 MIAC/ CINDAS ADMINISTRATOR PURDUE

  3. The Golosiiv on-line plate archive database, management and maintenance

    Science.gov (United States)

    Pakuliak, L.; Sergeeva, T.

    2007-08-01

    We intend to create online version of the database of the MAO NASU plate archive as VO-compatible structures in accordance with principles, developed by the International Virtual Observatory Alliance in order to make them available for world astronomical community. The online version of the log-book database is constructed by means of MySQL+PHP. Data management system provides a user with user interface, gives a capability of detailed traditional form-filling radial search of plates, obtaining some auxiliary sampling, the listing of each collection and permits to browse the detail descriptions of collections. The administrative tool allows database administrator the data correction, enhancement with new data sets and control of the integrity and consistence of the database as a whole. The VO-compatible database is currently constructing under the demands and in the accordance with principles of international data archives and has to be strongly generalized in order to provide a possibility of data mining by means of standard interfaces and to be the best fitted to the demands of WFPDB Group for databases of the plate catalogues. On-going enhancements of database toward the WFPDB bring the problem of the verification of data to the forefront, as it demands the high degree of data reliability. The process of data verification is practically endless and inseparable from data management owing to a diversity of data errors nature, that means to a variety of ploys of their identification and fixing. The current status of MAO NASU glass archive forces the activity in both directions simultaneously: the enhancement of log-book database with new sets of observational data as well as generalized database creation and the cross-identification between them. The VO-compatible version of the database is supplying with digitized data of plates obtained with MicroTek ScanMaker 9800 XL TMA. The scanning procedure is not total but is conducted selectively in the frames of special

  4. High efficiency and flexible working distance digital in-line holographic microscopy based on Fresnel zone plate

    Science.gov (United States)

    Tian, Peng; Hua, Yilei; Yang, Fan; Li, Fanxing; Hu, Song; Yan, Wei

    2017-05-01

    Traditional digital in-line holography suffers from twin-image noise problems and extremely short working distances between the object and light source. Here, we propose lensless Fourier transform digital in-line holographic microscopy based on a single optical element. A Fresnel zone plate is used to split the incident light into two parts: one is scattered along the original direction, the other is gathered at a focal point and the sample is put behind the focus. The interference fringe pattern, formed by the two beams, is recorded digitally by a CCD camera. A novel reconstruction algorithm is proposed to present the object image. The proof-of-concept experiments demonstrate that the proposed technique can eliminate the twin-image noise problem, improving the image contrast with high efficiency, and increasing the flexibility of the working distance. Furthermore, a wide field of view and no contact make it a promising tool for the study of materials science, biology and microelectronics.

  5. Effect of sodium dodecylbenzene sulfonate on the motion of three-phase contact lines on the Wilhelmy plate surface.

    Science.gov (United States)

    Karakashev, Stoyan I; Phan, Chi M; Nguyen, Anh V

    2005-11-15

    The combined approach of the molecular-kinetic and hydrodynamic theories for description of the motion of three-phase gas-liquid-solid contact lines has been examined using the Wilhelmy plate method. The whole dynamic meniscus has been divided into molecular, hydrodynamic, and static-like regions. The Young-Laplace equation and the molecular-kinetic and hydrodynamic dewetting theories have been applied to describe the meniscus profiles and contact angle. The dissipative forces accompanying the dynamic dewetting have also been investigated. The experiments with a Wilhelmy plate made from an acrylic polymer sheet were carried out using a computerized apparatus for contact angle analysis (OCA 20, DataPhysics, Germany). The extrapolated dynamic contact angle versus velocity of the three-phase contact line for Milli-Q water and 5x10(-4) M SDBS solution was experimentally obtained and compared with the combined MHD models with low and moderate Reynolds numbers. The models predict similar results for the extrapolated contact angle. SDBS decreases the equilibrium contact angle and increases the molecular jumping length but does not affect the molecular frequency significantly. The hydrodynamic deformation of the meniscus, viscous dissipation, and friction were also influenced by the SDBS surfactant.

  6. Effect of contact line dynamics on the thermocapillary motion of a droplet on an inclined plate.

    Science.gov (United States)

    Karapetsas, George; Sahu, Kirti Chandra; Matar, Omar K

    2013-07-16

    We study the two-dimensional dynamics of a droplet on an inclined, nonisothermal solid substrate. We use lubrication theory to obtain a single evolution equation for the interface, which accounts for gravity, capillarity, and thermo-capillarity, brought about by the dependence of the surface tension on temperature. The contact line motion is modeled using a relation that couples the contact line speed to the difference between the dynamic and equilibrium contact angles. The latter are allowed to vary dynamically during the droplet motion through the dependence of the liquid-gas, liquid-solid, and solid-gas surface tensions on the local contact line temperature, thereby altering the local substrate wettability at the two edges of the drop. This is an important feature of our model, which distinguishes it from previous work wherein the contact angle was kept constant. We use finite-elements for the discretization of all spatial derivatives and the implicit Euler method to advance the solution in time. A full parametric study is carried out in order to investigate the interplay between Marangoni stresses, induced by thermo-capillarity, gravity, and contact line dynamics in the presence of local wettability variations. Our results, which are generated for constant substrate temperature gradients, demonstrate that temperature-induced variations of the equilibrium contact angle give rise to complex dynamics. This includes enhanced spreading rates, nonmonotonic dependence of the contact line speed on the applied substrate temperature gradient, as well as "stick-slip" behavior. The mechanisms underlying this dynamics are elucidated herein.

  7. Investigation of possibilities for high heavy metal content sludges utilization by incorporating them in concrete products

    Directory of Open Access Journals (Sweden)

    Simeonova A.

    2006-01-01

    Full Text Available The safe removal of sludge, obtained during the surface treatment of different metal products, is a serious environmental problem. These sludges are usually characterized by a high content of heavy metals (Pb, Cu, Ni, Zn, Cr, Cd, Mn, low quality and are obtained in many small industrial units in the whole country, which makes their centralized treatment difficult. In world practice, different methods are used for component fixation of such sludge, in the aim to prevent leaching of the metals causing pollution of the soil and underground water. The aim of the recent work is to prepare the sludge in a form of light (keramzit fillers by preliminary treatment with binding substances and to introduce them in non supporting concrete products - curbs, stakes and similar products. The investigation was made with two types of sludge - from a production line for thermal treatment and hardening of different parts used in machine building and from a production line for surface decoration treatment (nickel-plating and chromium-plating of consumer products. The sludge were dried and ground and then granulated with a solution of water glass. After their solidifying the air dried granules with a size of 5 to 15 mm were treated with cement milk and air dried again. With the obtained granules, standard percolation test for leaching metals like Pb, Cu, Zn, Ni and Cr was carried out. After a preliminary calculation of concrete mixtures, these granules were mixed with Portland cement and concrete sample products were made. These molded concrete samples were characterized by their density, water absorption, and mechanical strength for defined standard periods of time. The samples were subjected to a modified percolation test for leaching metals. The metal concentration in eluates was determined by Atomic Spectral Analysis.

  8. Biocompatibility Analyses of Al₂O₃-Treated Titanium Plates Tested with Osteocyte and Fibroblast Cell Lines.

    Science.gov (United States)

    Smargiassi, Alberto; Bertacchini, Jessika; Checchi, Marta; Cavani, Francesco; Ferretti, Marzia; Palumbo, Carla

    2017-06-16

    Osseointegration of a titanium implant is still an issue in dental/orthopedic implants durable over time. The good integration of these implants is mainly due to their surface and topography. We obtained an innovative titanium surface by shooting different-in-size particles of Al₂O₃ against the titanium scaffolds which seems to be ideal for bone integration. To corroborate that, we used two different cell lines: MLO-Y4 (murine osteocytes) and 293 (human fibroblasts) and tested the titanium scaffolds untreated and treated (i.e., Al₂O₃ shot-peened titanium surfaces). Distribution, density, and expression of adhesion molecules (fibronectin and vitronectin) were evaluated under scanning electron microscope (SEM) and confocal microscope (CM). DAPI and fluorochrome-conjugated antibodies were used to highlight nuclei, fibronectin, and vitronectin, under CM; cell distribution was analyzed after gold-palladium sputtering of samples by SEM. The engineered biomaterial surfaces showed under SEM irregular morphology displaying variously-shaped spicules. Both SEM and CM observations showed better outcome in terms of cell adhesion and distribution in treated titanium surfaces with respect to the untreated ones. The results obtained clearly showed that this kind of surface-treated titanium, used to manufacture devices for dental implantology: (i) is very suitable for cell colonization, essential prerequisite for the best osseointegration, and (ii) represents an excellent solution for the development of further engineered implants with the target to obtain recovery of stable dental function over time.

  9. Thermal stress analysis of lining plate for dry quenching%干熄焦衬板的热应力分析

    Institute of Scientific and Technical Information of China (English)

    王厉刚; 李高阳; 滕杰; 马学东

    2012-01-01

    Lining plate of coke dram of dry quenching bears a greater thermal load. It is a damageable part that needs to replace frequently. And prolonging the lining plate life could reduce production cost and improve production efficiency. Thermal stress of the lining plate was analyzed quantificationally by using the finite clement method, and some measures were given to reduce the thermal stress. The work of this thesis provides theoretic foundation for prolonging lining plate life.%干熄焦焦罐衬板承受着较大的热载荷,属于经常更换的易损件,延长衬板的寿命,可以降低生产成本,提高生产效率.采用有限元方法,定量地分析了衬板的热应力,并提出了降低热应力的措施,所作工作为提高衬板寿命提供了理论依据.

  10. 中厚铝板表面处理及自动垛板生产线的研发%Research and development of aluminum plate surface treatment and automatic staking-plate production line

    Institute of Scientific and Technical Information of China (English)

    徐鸿钧; 葛延; 王廣收; 胡建华; 彭兵

    2011-01-01

    介绍了中国重型机械研究院为西南铝业有限公司中厚板车间设计成套的成品板材表面处理及真空吸附自动垛板生产线.该生产线采用了喷码机喷头防碰撞保护技术,板材运行纠偏技术,高精度的长、宽方向定位技术,高精度、高可靠性吸盘搬运装置、衬纸、覆膜技术等一系列新技术,具有对铝板表面进行自动清刷、喷码、对中、堆垛、衬纸等功能.基于PLC自动控制系统,采用集中监控管理,分散控制的多层次自动化系统,适用于实际生产中多规格的板材.生产线投产以来,运行稳定,性能指标达到设计要求.%The paper describes a complete set of finished aluminum plate surface treatment and vacuum absorption automatic plate staking-plate production line designed by China Heavy Machinery Research Institute for plate workshop of Southwest Aluminum(Group) Co. , Ltd.. This production line uses a series of new technologies such as anticollision protection for printers head, correcting a deviation in plate running, high-precision positioning for length and width, high-precision and high-reliability sucker handling device, paper backing and membrane-coveting. It has the functions of automatic cleaning, centering, stacking, and lining paper for aluminum plate surface. Based on PLC automatic control system, it uses the multi-level automation system of centralized monitoring management and decentralized control, which is suitable for plates of various sizes in the practical production. Since being put into production line, its operation is stable and all performance indexes are up to the design requirements.

  11. Routine removal of the plate after surgical treatment for mandibular angle fracture with a third molar in relation to the fracture line

    Science.gov (United States)

    Yamamoto, Kazuhiko; Matsusue, Yumiko; Horita, Satoshi; Murakami, Kazuhiro; Sugiura, Tsutomu; Kirita, Tadaaki

    2015-01-01

    Purpose: The purpose was to analyze the clinical course of surgically treated mandibular angle fractures from the viewpoint of routine removal of the plate because these fractures are associated with high rates of complications and plate removal. Subjects and Methods: The subjects were 40 patients with unilateral mandibular angle fracture, which was intraorally reduced and principally fixed with a single miniplate on the external oblique ridge. The third molar in relation to the fracture line was extracted in seven patients during the surgery. Clinical course was evaluated in terms of removal of the plate, preservation of the third molar and complications. Results: One patient showed a wound infection postoperatively, and two patients developed pericoronitis during the follow-up. These were managed with medication and local irrigation. One patient with a preserved third molar did not make a required visit and was lost from the follow-up. Removal of the plates was performed in 39 patients after confirmation of good fracture healing, mostly within a year. Twenty-four of 32 preserved third molars were simultaneously extracted. These procedures were generally performed under local anesthesia on an outpatient basis, and they did not cause any complications. Conclusions: Routine removal of the plate after surgical treatment for mandibular angle fractures, simultaneously with extraction of the third molar if indicated, may be beneficial to avoid complications related to the plate and the third molar later in life. PMID:26389039

  12. Create Your Plate

    Medline Plus

    Full Text Available ... steps to get started: Using your dinner plate, put a line down the middle of the plate. ... vegetables . Now in one of the small sections, put grains and starchy foods. See this list of ...

  13. In situ cannulation, microgrid follow-up and low-density plating provide first passage endothelial cell masscultures for in vitro lining.

    Science.gov (United States)

    Zilla, P; Fasol, R; Dudeck, U; Siedler, S; Preiss, P; Fischlein, T; Müller-Glauser, W; Baitella, G; Sanan, D; Odell, J

    1990-08-01

    A rapid and reliable harvest and culture technique was developed to provide a sufficient number of autologous endothelial cells for the confluent in vitro lining of cardiovascular prostheses. Enzymatic endothelial cell detachment was achieved by the in situ application of collagenase to short vessel segments. This harvest technique resulted in a complete lack of contaminating smooth muscle cells in all of 124 cultures from nonhuman primates and 13 cultures from human adults. The use of a microgrid technique enabled the daily in situ quantification of available endothelial cells. To assess ideal plating densities after passage the population doubling time was continuously related to the cell density. Surprisingly, a low plating density of 1.5 X 10(3) endothelial cells/cm2 achieved 43% shorter cell cycles than the usual plating density of 1.0 X 10(4) endothelial cells/cm2. Moreover, low density plating enabled mass cultures after one single cell passage, thereby reducing the cell damaging effect of trypsin. When the growth characteristics of endothelial cells from five anatomically different vessel sites were compared, the external jugular vein--which would be easily accessible and dispensable in each patient--proved to be an excellent source for endothelial cell cultures. By applying in situ administration of collagenase, low density plating and microgrid follow-up to adult human saphenous vein endothelial cells, 14,000,000 first passage endothelial cells--sufficient for the in vitro lining of long vascular prostheses--were obtained 26.2 days after harvest. (95% confidence interval:22.3 to 32.2 days).

  14. Application of Plate-and-Frame Filter Press for Sludge Dewatering in Water Treatment Plant%板框压滤机在自来水厂污泥脱水中的应用

    Institute of Scientific and Technical Information of China (English)

    袁华为

    2016-01-01

    This article described the water treatment plant sludge treatment situation,analyzed water treatment plant sludge dewatering methods and characteristics. Based on actual cases,actionable recommendations were put forward on sludge dewatering of water treatment plant,these conclusions on sludge dewatering problems may be meaningful to similar water treatment plants.%该文通过介绍某自来水厂的污泥处理状况,分析了利用各种脱水方式进行自来水污泥脱水的优缺点,根据实际案例,对小型自来水厂污泥处理设备设施提出了可操作的方案,为相似水厂在污泥脱水处理问题上提供参考。

  15. About one algorithm of the broken line approximation and a modeling of tool path for CNC plate cutting machines

    Science.gov (United States)

    Kurennov, D. V.; Petunin, A. A.; Repnitskii, V. B.; Shipacheva, E. N.

    2016-12-01

    The problem of approximating two-dimensional broken line with composite curve consisting of arc and line segments is considered. The resulting curve nodes have to coincide with source broken line nodes. This problem arises in the development of control programs for CNC (computer numerical control) cutting machines, permitting circular interpolation. An original algorithm is proposed minimizing the number of nodes for resulting composite curve. The algorithm is implemented in the environment of the Russian CAD system T-Flex CAD using its API (Application Program Interface). The algorithm optimality is investigated. The result of test calculation along with its geometrical visualization is given.

  16. 辊底式热处理炉在安钢中厚板热处理线上的应用%Application of roller hearth heat treatment line furnace in heat treatment line of Anyang heavy and medium plate

    Institute of Scientific and Technical Information of China (English)

    张万军

    2011-01-01

    The performance structure and application of roller hearth heat treatment furnace in heat treatment line of Anyang heavy and medium plate were introduced, discuss and analyze the existed issue during the furnace applying to produce, and adopt corresponding measure to improve simultaneous-ly.%介绍了安钢中厚板热处理生产线上辊底式热处理炉的性能、结构特点及应用情况,对存在的问题进行了分析讨论,并提出了相应的改进措施.

  17. Thickness monitor for floated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, J.; Grecu, G.M.

    1989-10-31

    This patent describes apparatus for determining the thickness of a layer of aerated sludge floating on a layer of a heavier liquid in a tank. It comprises: a frame means which can be positioned to extend vertically into the tank; horizontally-extending indicator means supported by and moveable vertically with respect to a portion of the frame means extending vertically into the tank. The indicator means being selectively positionable at the highest level of sludge in the tank; horizontally-extending lower base means attached to the frame means at or near the bottom thereof; horizontally-extending upper base means attached to the frame means at or near the top thereof; and a line carrying a float means. The line being movable secured at the upper base means and the lower base means. The float means being floatable on the liquid and including a horizontally-extending portion presenting an upwardly directed generally planar surface, which surface will be parallel to the interface of the sludge and liquid.

  18. Influence of the contact line velocity on the finger formation of the liquid film expanding on an inclined plate

    Science.gov (United States)

    Yamashita, Masatoshi; Nishikawa, Masato; Ito, Takahiro; Tsuji, Yoshiyuki

    2015-11-01

    When a liquid film flows down on an inclined solid surface, the contact line can be destabilized to finger shape. This phenomenon leads to the non-uniform height of the liquid surface or even to generation of dry patch, and then has a great effect on cooling of energy device and quality of coating. In previous studies, the final finger shapes have been discussed by relating the with capillary (Ca) number and the wetting properties of the liquid for the solid substrate, i.e. the contact angle. However, in the experimental studies, little attention has been paid on the difference between the static contact angle and the dynamic one, the latter which is actually observed when the finger is developing. In this study, we performed three-dimensional measurement of surface geometry of the liquid film to clarify how the dynamic contact angles and the Ca number influence the finger shape by optical method. We observed two different finger shapes depending on the volumes of the working fluid., and verified that the finger shapes depend on the contact angle scaled by Ca number. We found that the local dynamic contact angle and the contact line velocity on the trough part of the wavy contact line can be highly related with the final finger shape.

  19. A recombinant matriptase causes an increase in caspase-3 activity in a small-intestinal epithelial IEC-6 line cultured on fibronectin-coated plates.

    Science.gov (United States)

    Mochida, Seiya; Tsuzuki, Satoshi; Inouye, Kuniyo; Fushiki, Tohru

    2014-05-01

    Matriptase is an epithelial-derived type-II transmembrane serine protease. This protease is expressed prominently in the villus tip of small-intestinal epithelia at which senescent cells undergo shedding and/or apoptosis. The basement membrane of epithelial cells, including small-intestinal epithelial cells, contains extracellular matrix (ECM) proteins such as fibronectin and laminin. We found previously that high concentrations of a recombinant matriptase catalytic domain (r-MatCD) (e.g. 1 μM) caused an increased detachment of and increases in the activity of apoptotic effector caspase-3 in a rat small-intestinal epithelial IEC-6 line cultured on laminin-coated plates and proposed that at sites with its high level of expression, matriptase contributes to promoting shedding and/or detachment-induced death of epithelial cells through a mechanism mediating loss of cell-ECM adhesion. In this study, we found that even without increasing cell detachment, a high concentration of r-MatCD causes an increase in caspase-3 activity in IEC-6 cells cultured on fibronectin-coated plates, suggesting that the recombinant matriptase can cause apoptosis by a mechanism unrelated to cell detachment. Also, r-MatCD-treated IEC-6 cells on fibronectin were found to display spindle-like morphological changes. We suggest that r-MatCD causes apoptosis of IEC-6 on fibronectin by a mechanism involving the disruption of cell integrity.

  20. Biocompatibility Analyses of Al2O3-Treated Titanium Plates Tested with Osteocyte and Fibroblast Cell Lines

    OpenAIRE

    Smargiassi, Alberto; Bertacchini, Jessika; Checchi, Marta; Cavani, Francesco; Ferretti, Marzia; Palumbo, Carla

    2017-01-01

    Osseointegration of a titanium implant is still an issue in dental/orthopedic implants durable over time. The good integration of these implants is mainly due to their surface and topography. We obtained an innovative titanium surface by shooting different-in-size particles of Al2O3 against the titanium scaffolds which seems to be ideal for bone integration. To corroborate that, we used two different cell lines: MLO-Y4 (murine osteocytes) and 293 (human fibroblasts) and tested the titanium sc...

  1. Performance evaluation of a bipolar electrolysis/electrocoagulation (EL/EC) reactor to enhance the sludge dewaterability.

    Science.gov (United States)

    Gharibi, Hamed; Sowlat, Mohammad Hossein; Mahvi, Amir Hossein; Keshavarz, Morteza; Safari, Mohammad Hossein; Lotfi, Saeedeh; Bahram Abadi, Mahnaz; Alijanzadeh, Azim

    2013-01-01

    The present study aimed to evaluate the performance of a bipolar electrolysis/electrocoagulation reactor designed to enhance the sludge dewaterability. The reactor was 15 L in volume, with two series of plates used in it; Ti/RuO(2) plates for the electrolysis of the sludge, and also aluminum and iron plates for electrocoagulation process. The dewaterability of the sludge was determined in terms of its capillary suction time (CST) and specific resistance to filtration (SRF), while the degree of sludge disintegration was determined based on the value of degree of sludge disintegration (DD(SCOD)). The maximum reduction in CST and SRF was observed at a detention time of 20 min and a voltage of 30 V. However, increasing of both detention time and voltage significantly increased the values of CST and SRF even to an extent that they both exceeded those of the untreated sludge. The optimal degree of sludge disintegration achieved by the present study was 2.5%, which was also achieved at a detention time of 20 min and a voltage of 30V. As reported previously, increased DD(SCOD) values led to increasing CST and SRF values, due primarily to the disruption of the sludge flocs. According to the results from the present study, it can be concluded that simultaneous application of electrocoagulation and electrolysis is effective in enhancing the sludge dewaterability, because electrocoagulation helps to achieve a higher degree of sludge disintegration while maintaining the desired sludge dewaterability.

  2. Development of Plate Reader and On-Line Microfluidic Screening to Identify Ligands of the 5-Hydroxytryptamine Binding Protein in Venoms

    Directory of Open Access Journals (Sweden)

    Reka A. Otvos

    2015-06-01

    Full Text Available The 5-HT3 receptor is a ligand-gated ion channel, which is expressed in the nervous system. Its antagonists are used clinically for treatment of postoperative- and radiotherapy-induced emesis and irritable bowel syndrome. In order to better understand the structure and function of the 5-HT3 receptor, and to allow for compound screening at this receptor, recently a serotonin binding protein (5HTBP was engineered with the Acetylcholine Binding Protein as template. In this study, a fluorescence enhancement assay for 5HTBP ligands was developed in plate-reader format and subsequently used in an on-line microfluidic format. Both assay types were validated using an existing radioligand binding assay. The on-line microfluidic assay was coupled to HPLC via a post-column split which allowed parallel coupling to a mass spectrometer to collect MS data. This high-resolution screening (HRS system is well suitable for compound mixture analysis. As a proof of principle, the venoms of Dendroapsis polylepis, Pseudonaja affinis and Pseudonaja inframacula snakes were screened and the accurate masses of the found bioactives were established. To demonstrate the subsequent workflow towards structural identification of bioactive proteins and peptides, the partial amino acid sequence of one of the bioactives from the Pseudonaja affinis venom was determined using a bottom-up proteomics approach.

  3. Biocompatibility Analyses of Al2O3-Treated Titanium Plates Tested with Osteocyte and Fibroblast Cell Lines

    Science.gov (United States)

    Smargiassi, Alberto; Bertacchini, Jessika; Checchi, Marta; Cavani, Francesco; Ferretti, Marzia; Palumbo, Carla

    2017-01-01

    Osseointegration of a titanium implant is still an issue in dental/orthopedic implants durable over time. The good integration of these implants is mainly due to their surface and topography. We obtained an innovative titanium surface by shooting different-in-size particles of Al2O3 against the titanium scaffolds which seems to be ideal for bone integration. To corroborate that, we used two different cell lines: MLO-Y4 (murine osteocytes) and 293 (human fibroblasts) and tested the titanium scaffolds untreated and treated (i.e., Al2O3 shot-peened titanium surfaces). Distribution, density, and expression of adhesion molecules (fibronectin and vitronectin) were evaluated under scanning electron microscope (SEM) and confocal microscope (CM). DAPI and fluorochrome-conjugated antibodies were used to highlight nuclei, fibronectin, and vitronectin, under CM; cell distribution was analyzed after gold-palladium sputtering of samples by SEM. The engineered biomaterial surfaces showed under SEM irregular morphology displaying variously-shaped spicules. Both SEM and CM observations showed better outcome in terms of cell adhesion and distribution in treated titanium surfaces with respect to the untreated ones. The results obtained clearly showed that this kind of surface-treated titanium, used to manufacture devices for dental implantology: (i) is very suitable for cell colonization, essential prerequisite for the best osseointegration, and (ii) represents an excellent solution for the development of further engineered implants with the target to obtain recovery of stable dental function over time. PMID:28621746

  4. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  5. Activated Sludge Rheology

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  6. Respirometry in activated sludge

    NARCIS (Netherlands)

    Spanjers, H.

    1993-01-01

    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.

    A

  7. Hot balls dry sludge

    NARCIS (Netherlands)

    Hartmann, L.

    2004-01-01

    Each year some 25 million m3 of mineral sludge are dredged from rivers, canals and harbours in the Netherlands alone, twenty percent of which is polluted. The unpolluted sludge is usually dumped at sea. The remaining five million m3 may only be dumped in a few selected landfill locations, at conside

  8. Deep Sludge Gas Release Event Analytical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sams, Terry L.

    2013-08-15

    Long Abstract. Full Text. The purpose of the Deep Sludge Gas Release Event Analytical Evaluation (DSGRE-AE) is to evaluate the postulated hypothesis that a hydrogen GRE may occur in Hanford tanks containing waste sludges at levels greater than previously experienced. There is a need to understand gas retention and release hazards in sludge beds which are 200 -300 inches deep. These sludge beds are deeper than historical Hanford sludge waste beds, and are created when waste is retrieved from older single-shell tanks (SST) and transferred to newer double-shell tanks (DST).Retrieval of waste from SSTs reduces the risk to the environment from leakage or potential leakage of waste into the ground from these tanks. However, the possibility of an energetic event (flammable gas accident) in the retrieval receiver DST is worse than slow leakage. Lines of inquiry, therefore, are (1) can sludge waste be stored safely in deep beds; (2) can gas release events (GRE) be prevented by periodically degassing the sludge (e.g., mixer pump); or (3) does the retrieval strategy need to be altered to limit sludge bed height by retrieving into additional DSTs? The scope of this effort is to provide expert advice on whether or not to move forward with the generation of deep beds of sludge through retrieval of C-Farm tanks. Evaluation of possible mitigation methods (e.g., using mixer pumps to release gas, retrieving into an additional DST) are being evaluated by a second team and are not discussed in this report. While available data and engineering judgment indicate that increased gas retention (retained gas fraction) in DST sludge at depths resulting from the completion of SST 241-C Tank Farm retrievals is not expected and, even if gas releases were to occur, they would be small and local, a positive USQ was declared (Occurrence Report EM-RP--WRPS-TANKFARM-2012-0014, "Potential Exists for a Large Spontaneous Gas Release Event in Deep Settled Waste Sludge"). The purpose of this technical

  9. Activated sludge model No. 3

    DEFF Research Database (Denmark)

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

    1999-01-01

    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...

  10. Sludge minimization technologies - an overview

    Energy Technology Data Exchange (ETDEWEB)

    Oedegaard, Hallvard

    2003-07-01

    The management of wastewater sludge from wastewater treatment plants represents one of the major challenges in wastewater treatment today. The cost of the sludge treatment amounts to more that the cost of the liquid in many cases. Therefore the focus on and interest in sludge minimization is steadily increasing. In the paper an overview is given for sludge minimization (sludge mass reduction) options. It is demonstrated that sludge minimization may be a result of reduced production of sludge and/or disintegration processes that may take place both in the wastewater treatment stage and in the sludge stage. Various sludge disintegration technologies for sludge minimization are discussed, including mechanical methods (focusing on stirred ball-mill, high-pressure homogenizer, ultrasonic disintegrator), chemical methods (focusing on the use of ozone), physical methods (focusing on thermal and thermal/chemical hydrolysis) and biological methods (focusing on enzymatic processes). (author)

  11. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor.

    Science.gov (United States)

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

    2008-12-01

    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.

  12. Biosolids and Sludge Management.

    Science.gov (United States)

    Fitzmorris Brisolara, Kari; Ochoa, Helena

    2016-10-01

    This review section covers journal articles and conference papers related to biosolids and sludge management that were published in 2015. The literature review has been divided into the following sections: • Biosolids regulations and management issues; • Biosolids characteristics, quality and measurement including microconstituents, pathogens, nanoparticles and metals; • Sludge treatment technologies including pretreatment and sludge minimization, conditioning and dewatering, digestion, composting and innovative technologies; • Disposal and reuse including combustion/incineration, agricultural uses and innovative uses; • Odor and air emissions; and • Energy issues.

  13. Depuration sludges in agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Marchese, F.; Nappi, P.; Onofrio, M.; Barberis, R. (Politecnico di Torino (Italy). Dipt. di Scienza dei Materiali e Ingegneria Chimica)

    The study examines 5 sludges coming from different scale municipal waste treatment plants and some other 8 produced by waste treatment of as many different industrial plants. The studied sludges were characterized both through chemical and microbiological analyses. Biological assays were made to evaluate phytotoxicity and pot cultivation assays using Lepidium Sativum as test plant. Toxic metals transfer from the soil to the plant was found to take place in the following decreasing order: Zn Cr Cd Ni Cu Pb. Metal transfer coefficient is lower for sludge-soil mixtures than tor soil alone probably because of the metals different chemical form.

  14. 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.

    1997-06-01

    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.

  15. Galvanic sludge metals recovery by pyrometallurgical and hydrometallurgical treatment.

    Science.gov (United States)

    Rossini, Gustavo; Bernardes, Andréa Moura

    2006-04-17

    This paper reports a study, on laboratory scale, of sulphating roasting to perform a treatment for a selective recovery of valuable metals from galvanic sludge. The target metals were copper, zinc and nickel and the sulphating agent used was pyrite, from coal wastes. The particularity of this treatment is the use of two hazardous wastes as raw material. They are generated in large quantities at coal extraction sites (coal wastes) and at plating shops (galvanic sludge). The wastes were characterized by X-ray fluorescence (XRF), particle size distribution and water contents. The chemical characterization showed sludges with high copper concentration, with more than 14% (dry base). In the roasting step, the galvanic sludge was mixed with pyritic waste and the parameters evaluated were galvanic sludge/pyrite ratio, roasting temperature and roasting time. After roasting, the product of reaction was leached with water in room temperature for 15 min. Considering that other studies have already demonstrated that the pyrometallurgical step determines the process efficiency, this paper only reports the influence of pyrometallurgical parameters. Hydrometallurgical processes will be better evaluated in further studies. The conditions that best reflect a compromise between the valuable metal recover and the economical viability of the process were achieved for 1:0.4 galvanic sludge/pyrite ratio, 90 min of roasting time and 550 degrees C of roasting temperature. These conditions lead to a recovery of 60% zinc, 43% nickel and 50% copper.

  16. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  17. Evaluation of control parameters of the activated sludge process

    Energy Technology Data Exchange (ETDEWEB)

    Stall, T.R.; Sherrard, J.H.

    1978-03-01

    The evaluation of control parameters of the activated sludge process was effected with a laboratory-scale, completely mixed process employing internal cell recycle and an artificial wasterwater over a wide spectrum of conditions at full-scale facilities. The parameters: food-microorganism ratio, specific utilization rate, COD or BOD sludge age, and aeration and total system mean cell residence time can all be used to control an activated sludge wastewater treatment plant. Because of the sensitivity of the COD or BOD sludge age (when compared with measures of mean cell residence time), its use may be of limited value. The aeration basin cell residence time may be favored over the total system mean cell residence time because of the ease in measuring aeration basin solids and the difficulty in measuring solids concentration at the bottom of the secondary clarifier and in the recycle line.

  18. Biotreatment of oily sludges

    Energy Technology Data Exchange (ETDEWEB)

    Dirks, J. [Biogenie Inc., Calgary, AB (Canada)

    2009-07-01

    This presentation discussed a biotreatment process used at a petrochemical plant near Montreal, Quebec. The plant used a sedimentation pond that contained oily sludge with a total polycyclic hydrocarbon (TPH) content averaging 170,000 mg/kg. The aim of the remediation project was to remove the oily sludge and impacted clay at the bottom of the pond, and redesign the pond to meet current provincial regulations. Studies were conducted to evaluate bulking agents, estimate performance and determine the presence of potential inhibitors. Organic and inorganic nutrients were tested as a means of amending the sludge. An ex-situ biopile was used to treat the impacted waste. After a period of 5 months, concentrations were below the applicable criteria for Montreal urban community and provincial guidelines. A drainage system and membrane was then added to the pond. tabs., figs.

  19. Bioleaching of heavy metals from sewage sludge using Acidithiobacillus thiooxidans

    Science.gov (United States)

    Wen, Ye-Ming; Lin, Hong-Yan; Wang, Qing-Ping; Chen, Zu-Liang

    2010-11-01

    Acidithiobacillus thiooxidans was isolated from sewage sludge using the incubation in the Waksman liquor medium and the inoculation in Waksman solid plate. It was found that the optimum conditions of the bioleaching included solid concentration 2%, sulfur concentration 5 gṡL-1 and cell concentration 10%. The removal efficiency of Cr, Cu, Pb and Zh in sewage sludge, which was obtained from waste treatment plant, Jinshan, Fuzhou, was 43.65%, 96.24%, 41.61% and 96.50% in the period of 4˜10 days under the optimum conditions, respectively. After processing using the proposed techniques, the heavy metals in sewage sludge did meet the requirement the standards of nation.

  20. 镀镍槽液中镍含量的在线监测系统研究%Concentration of Nickel in Nickel Plating Bath by on-line Monitoring System

    Institute of Scientific and Technical Information of China (English)

    乔永莲; 沙春鹏; 董宇; 刘冰

    2015-01-01

    Objective To develop a new method for on-line monitoring of the concentration of nickel ions in nickel plating, and to expand its application to chromeplate, cadmium plating, copper plating and so on. Methods The system was composed by VC++Language programming, Modbus communication technology and PLC Siemens technology. The amount of nickel plating bath was controlled and revised by meter pump and flowmeter for nickel ion monitoring. The bath solution was automatically monitored by electrochemical testing method and then the results were collected by VC++Language programming. Thus, the composition of nick-el plating bath can be automatically monitored by this excellent and reliable method. Results The relationship between the nickel ions and the polarization current value at-1. 0 V(vs. SCE)was fitted as I=0. 002 01+6. 90×10-5ρby the system of on-line monito- ring of nickel ion concentration. For 120 g/L nickel plating solution, the concentration of the nickel ions was detected as 115. 5 g/L and 113. 7 g/L and the measuring error was 3. 78% and 5. 25% by this on-line monitoring and the EDTA titrimetric analysis, re-spectively. Conclusion With its high reliability, the system can not only be used to monitor the status of nickel plating bath, but also for the cadmium plating bath and the chromium plating bath. Most importantly, it can be used in harsh environment.%目的 研发一种能够在线监测镀镍槽液中镍离子含量的测试系统,并将此方法推广至镀铬、镉、铜等槽液. 方法 利用计算机VC++语言编程技术、Modbus通讯技术、西门子PLC技术组成监控系统,通过耐酸碱计量泵和耐酸碱流量计对镀镍槽液取液量进行控制和校正,采用电化学测试方法对待测槽液在线监测,采用VC++语言编程技术采集电化学测试数据,最终实现对镀镍槽液中镍离子含量的自动监测.结果 采用此自动控制系统测量镀镍槽液中镍离子的质量浓度,其与极化曲线中-1. 0 V

  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.

    2003-01-01

    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. Casagra......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....... 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...

  2. Sewage sludge treatment system

    Science.gov (United States)

    Kalvinskas, John J. (Inventor); Mueller, William A. (Inventor)

    1976-01-01

    Raw sewage may be presently treated by mixing screened raw sewage with activated carbon. The mixture is then allowed to stand in a first tank for a period required to settle the suspended matter to the bottom of the tank as a sludge. Thereafter, the remaining liquid is again mixed with activated carbon and the mixture is transferred to a secondary settling tank, where it is permitted to stand for a period required for the remaining floating material to settle as sludge and for adsorption of sewage carbon as well as other impurities to take place. The sludge from the bottom of both tanks is removed and pyrolyzed to form activated carbon and ash, which is mixed with the incoming raw sewage and also mixed with the liquid being transferred from the primary to the secondary settling tank. It has been found that the output obtained by the pyrolysis process contains an excess amount of ash. Removal of this excess amount of ash usually also results in removing an excess amount of carbon thereby requiring adding carbon to maintain the treatment process. By separately pyrolyzing the respective sludges from the first and second settling tanks, and returning the separately obtained pyrolyzed material to the respective first and second tanks from which they came, it has been found that the adverse effects of the excessive ash buildup is minimized, the carbon yield is increased, and the sludge from the secondary tank can be pyrolyzed into activated carbon to be used as indicated many more times than was done before exhaustion occurs.

  3. Commissioning of Turbid Circulating Water System of Heavy Plate Rolling Line and Improvement Measures%轧钢厚板线浊循环水系统调试及改进措施

    Institute of Scientific and Technical Information of China (English)

    范学军

    2014-01-01

    The system configuration and installation commissioning method of the turbid circulating water system of the 4100mm medium-heavy plate production line at Chongqing Steel are presented. Improvement measures were put forward regarding existing problems dur-ing system operation, which has achieved better results.%主要介绍了重钢中厚板厂4100mm线浊循环水的系统组成及安装调试方法;针对系统运行中存在的问题,提出了改进措施,取得了良好的改进效果。

  4. K Basins sludge removal temporary sludge storage tank system

    Energy Technology Data Exchange (ETDEWEB)

    Mclean, M.A.

    1997-06-12

    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.

  5. Activated sludge inhibition capacity index

    Directory of Open Access Journals (Sweden)

    V. Surerus

    2014-06-01

    Full Text Available Toxic compounds in sewage or industrial wastewater may inhibit the biological activity of activated sludge impairing the treatment process. This paper evaluates the Inhibition Capacity Index (ICI for the assessment of activated sludge in the presence of toxicants. In this study, activated sludge was obtained from industrial treatment plants and was also synthetically produced. Continuous respirometric measurements were carried out in a reactor, and the oxygen uptake rate profile obtained was used to evaluate the impact of inhibiting toxicants, such as dissolved copper, phenol, sodium alkylbenzene sulfonate and amoxicillin, on activated sludge. The results indicate that ICI is an efficient tool to quantify the intoxication capacity. The activated sludge from the pharmaceutical industry showed higher resistance than the sludge from other sources, since toxicants are widely discharged in the biological treatment system. The ICI range was from 58 to 81% when compared to the synthetic effluent with no toxic substances.

  6. 连续电镀锌机组预镀镍设备及工艺特点%Equipment and Process Features of Ni-flash Plating in the Continuous Electro Galvanizing Line

    Institute of Scientific and Technical Information of China (English)

    陈晓晓

    2014-01-01

    介绍了连续电镀锌机组的预镀镍过程,详细说明了镀镍设备的优点和预镀镍的工艺条件。采用性能优良的镀镍槽和不溶阳极时,如何保证镀液的 PH 值在3~4是关键的工艺条件,着重介绍了阴离子交换树脂中和 SO2-4和释放 OH-去维持镀液 PH 值的原理。%Ni-flash plating process of the continuous electro galvanizing line (EGL)is described.This report mainly explains the equipment and process conditions of Ni-flash plating.When the Ni-flash plating cell of excellent performance and insoluble anode are applied,maintain the PH value between 3~4 is the key process condition which can be achieved by using anion-exchange resin to absorb SO2-4 and release OH- .

  7. [Technology of sewage sludge hygienization].

    Science.gov (United States)

    Keller, U

    1983-09-01

    That the use of modern technology against the laws of Nature must fail, has been clearly demonstrated again some years ago when sewage sludge postpasteurization was rashly introduced. Although many attempts were made to improve this procedure, it had to be abandoned because of unavoidable massive regrowth of pathogens which invaded the germ-free postpasteurized sludge. In contrast of postpasteurization, long-term large-scale tests with the pasteurization of fresh sludge (prepasteurization) have demonstrated that this procedure where methane digestion with its pathogen displacing effect constitutes the final stage, is basically able to function. With respect to the Swiss Sewage Sludge Decree which came into force in May 1981, and which imposes sludge hygienization for most applications throughout the year, various thermal prepasteurization methods have been offered on the market ready for application to meet the legally prescribed requirements. However, some of them still need selective improvements in order to ensure the desired hygienisation effect permanently. For some time now, attention has been focussed on a novel biological 2-stage procedure based on partial aerobic thermophilic fermentation followed by anaerobic sludge digestion which in addition to good hygienisation promises improved sludge thickening, reduced digestion time, more favourable energy consumption and added process stability etc. Although it has already been offered on the market, this interesting process is being thouroughly tested and optimized in parallel pilot tests plant at the WWTP Altenrhein. Finally, reference is made to further sludge treatment processes such as sludge drying and sludge composting which mostly comprise efficent sludge hygienisation although they may not entirely prevent pathogenic regrowth. Moreover, some unconventional and less popular processes such as liquid sludge irradiation and chemical methods are also mentioned.

  8. Activated Sludge Ozonation to Reduce Sludge Production in MBR

    Institute of Scientific and Technical Information of China (English)

    HE Sheng-bing; XUE Gang; WANG Bao-zhen

    2005-01-01

    The total experimental period was divided into two stages.At the first stage, a series of batch studies were carried out to get an understanding of the effect of ozonation on sludge properties. At the following stages, three MBRs with different amounts of activated sludge to be ozonated were run in parallel for a long period to evaluate the influence of sludge ozonation on sludge yield and permeate quality.Through batch study, it was found that ozone could disrupt the cell walls and caused the release of plasm from the cells,then the amounts of soluble organics in the solution increased with ozonation time. With the rise of soluble organics, the amount of soluble organics to be mineralized increased as well, which wonld reduce the soluble organics content. For the counteraction between these two aspects, a pseudo-balance could be achieved, and soluble organics would vary in a limited range. Sludge ozonation also increased the contents of nitrogen and phosphorus in the solution. In addition, ozonation was effective in improving sludge settling property. On the basis of batch study, a suitable ozone dosage of 0.16 kgO3/kgMLSS wasdetermined. Three systems were run in parallel for a total period of 39 days, it was demonstrated that a part of activated sludge ozonation could reduce sludge production significantly, and biological performance of mineralization and nitrification would not be inhibited due to sludge ozonation. Experimental results proved that the combination of ozonation unit with MBR unit could achieve an excellent quality of permeate as well as a small quantity of sludge production, and economic analysis indicated that an additional ozonation operating cost for treatment of both wastewater and sludge was only 0.096Yuan (US $0.011,5)/m3 wastewater.

  9. Experimental Study of Bad Contact of Low-Voltage Line Based on Needle-Plate Model%基于针-板模型低压电气线路接触不良的试验研究

    Institute of Scientific and Technical Information of China (English)

    胡帅; 王成江; 李如锋; 李光

    2012-01-01

      This paper made a needle-plate model to make clear of discharge position and to identify discharge characteristics of low-voltage line when discharge appeared on line load due to bad contact. By changing the position of the needle-plate model in the circuit, the digital oscil-loscope was adopted to collect the voltage waveforms of null line when model was in different position. The experiment study shows that there are different discharge characteristics of null line voltage waveforms when the model is in different position, which has definite regularity.%  为解决低压电气线路因出现接触不良而发生放电,及其放电源位置的确定和放电特征识别等问题,制作了针-板模型来模拟导体间接触不良。通过改变针-板模型位于线路中的位置,利用数字示波器采集模型处于线路不同位置时零线上的电压波形。试验表明:模型处于线路不同位置发生放电现象,其对应的零线电压波形具有不同的放电特征且具有一定的规律性。

  10. Application of New Yoke Plate Wire Grip for Transmission Line in Maintenance%输电线路用新型联板紧线器在检修工作中的应用

    Institute of Scientific and Technical Information of China (English)

    郑浩; 廖志斌; 李德波; 于启万

    2015-01-01

    Combined with the present situation of the maintenance of twin insulator strings of transmission line, the problems of the wire grip in the maintenance work are discussed , aiming at proposing a mainte-nance tactics to replace the twin insulator strings of 110kV and over transmission line tower , and resolving the problem of just using tool to fasten yoke plate , and a kind of wire grip which can fasten two yoke plates and string is researched .%结合输电线路双联串绝缘子检修现状,对输电线路检修工作中的紧线器存在的问题进行了探讨,旨在提出一种用于更换110千伏及以上输电线路杆塔双联串绝缘子的检修策略,解决使用工具单独固定联板的难题,并研究一种可以固定两个联板然后进行紧线的紧线器工具。

  11. Solids Control in Sludge Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Beahm, E.C., Weber, C.F., Hunt, R.D., Dillow, T.A.

    1997-12-31

    Sludge pretreatment will likely involve washing, followed by caustic or acidic leaching and washing of sludge residues after leaching. The principal goal of pretreatment is to obtain a low-volume high-activity waste stream and a high-volume low-activity waste stream. Also, some waste constituents such as chromium and phosphate can be included in glass formulations only at very low concentrations; therefore, it is desirable to remove them from high-level waste streams. Two aspects of sludge treatment and subsequent separations should be well delineated and predictable: (1) the distribution of chemical species between aqueous solutions and solids and (2) potential problems due to chemical interactions that could result in process difficulties or safety concerns.Before any treatment technology is adopted, it must be demonstrated that the process can be carried out as planned. Three pretreatment methods were considered in the Tri-Party (Washington State Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy) negotiations: (1) sludge washing with corrosion- inhibiting water, (2) Enhanced Sludge Washing, and (3)acidic dissolution with separations processes. Enhanced Sludge Washing is the baseline process. In Enhanced Sludge Washing, sludge is first washed with corrosion-inhibiting water; it is then leached with caustic (sodium hydroxide solution) and washed again with corrosion- inhibiting water. The initial concern is whether a pretreatment technique is effective in separating sludge components. This can be evaluated by bench-scale tests with sludge specimens from underground storage tanks. The results give data on the distribution of important species such as aluminum, phosphate, and radionuclides between wash and leach solutions and solid sludge residues.

  12. Sludge Digestion Manual; Handboek Slibgisting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    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.

  13. CASE HISTORY REPORT ON MILWAUKEE CERAMIC PLATE AERATION FACILITIES

    Science.gov (United States)

    Ceramic plate diffusers were among the earliest forms of fine pore diffusers used in activated sludge treatment. They have successfully used for over 60 years in the Jones Island West Plant of the Milwaukee Metropolitan Sewerage District (MMSD) and since 1935 and 1974, respective...

  14. The influence of clay fineness upon sludge recycling in a ceramic matrix

    Science.gov (United States)

    Szőke, A. M.; Muntean, M.; Sándor, M.; Brotea, L.

    2016-04-01

    The feasibility of sludge recycling in the ceramic manufacture was evaluated through laboratory testing. Such residues have similar chemical and mineralogical composition with the raw mixture of the green ceramic body used in construction. Several ceramic masses with clay and various proportion of sludge have been synthesized and then characterized by their physical-mechanical properties. The fineness of the clay, the main component of the green ceramic body, has been considered for every raw mixture. The proportion of the sludge waste addition depends on the clay fineness and the sintering capacity also, increases with the clay fineness. The ceramic properties, particularly, the open porosity, and mechanical properties, in presence of small sludge proportion (7, 20%) shows small modification. The introduction of such waste into building ceramic matrix (bricks, tiles, and plates) has a very good perspective.

  15. A Technology of Wastewater Sludge Treatment

    Science.gov (United States)

    Gizatulin, R. A.; Senkus, V. V.; Valueva, A. V.; Baldanova, A. S.; Borovikov, I. F.

    2016-04-01

    At many communities, industrial and agricultural enterprises, treatment and recycling of wastewater sludge is an urgent task as the sludge is poured and stored in sludge banks for many years and thus worsens the ecology and living conditions of the region. The article suggests a new technology of wastewater sludge treatment using water-soluble binder and heat treatment in microwave ovens.

  16. DETECTION OF ODSCC IN SG TUBES DEPENDING ON THE SIZE OF THE CRACK AND ON THE PRESENCE OF SLUDGE DEPOSITS

    Directory of Open Access Journals (Sweden)

    HANSUB CHUNG

    2014-12-01

    Full Text Available It was discovered in a Korean PWR that an extensive number of very short and shallow cracks in the SG tubes were undetectable by eddy current in-service-inspection because of the masking effect of sludge deposits. Axial stress corrosion cracks at the outside diameter of the steam generator tubes near the line contacts with the tube support plates are the major concern among the six identical Korean nuclear power plants having CE-type steam generators with Alloy 600 high temperature mill annealed tubes, HU3&4 and HB3∼6. The tubes in HB3&4 have a less susceptible microstructure so that the onset of ODSCC was substantially delayed compared to HU3&4 whose tubes are most susceptible to ODSCC among the six units. The numbers of cracks detected by the eddy current inspection jumped drastically after the steam generators of HB4 were chemically cleaned. The purpose of the chemical cleaning was to mitigate stress corrosion cracking by removing the heavy sludge deposit, since a corrosive environment is formed in the occluded region under the sludge deposit. SGCC also enhances the detection capability of the eddy current inspection at the same time. Measurement of the size of each crack using the motorized rotating pancake coil probe indicated that the cracks in HB4 were shorter and substantially shallower than the cracks in HU3&4. It is believed that the cracks were shorter and shallower because the microstructure of the tubes in HB4 is less susceptible to ODSCC. It was readily understood from the size distribution of the cracks and the quantitative information available on the probability of detection that most cracks in HB4 had been undetected until the steam generators were chemically cleaned.

  17. Resistance evaluation of distillation tower welded metal plate linings to corrosion caused by heavy crude oil; Avaliacao da resistencia a corrosao causada por petroleo pesado em chapas soldadas utilizadas em 'linings' de torres de destilacao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleiton Carvalho; Farias, Jesualdo Pereira [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Metalurgica e de Materiais], e-mail: cleitonufc@yahoo.com.br, e-mail: jpf@secrel.com.br; Sant' Ana, Hosilberto Batista de [' Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Quimica], e-mail: hbs@ufc.br

    2008-04-15

    This study evaluated the microstructures and the resistance of AISI 316L, 410S and 444 stainless steel welded joints to heavy crude oil corrosion, using the AWS E309MoL-16 electrode. The above mentioned stainless steel plates were welded applying three energy levels (6; 9 and 12kJ/cm). Experimental sample forms were obtained from the welded plates, which were thermally treated at 200 and 300 deg C and immersed (annealed) in heavy crude oil. The techniques of optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were employed to make the microstructure evaluation, in addition to the surface characterization and the corrosion product identification. It was concluded that the welding thermal cycle is sufficient to cause metallurgic alterations in the region of the heat-affected zone (HAZ), making the region more susceptible to corrosion. It was also observed that the rate of corrosion varied according to the welding parameters applied. (author)

  18. 插头镀金线镀层厚度计算模型研究%Study on calculational model for the electrodeposited coatings thickness of nickel and gold about plug gold plating line

    Institute of Scientific and Technical Information of China (English)

    高来华; 陈海燕

    2014-01-01

    电镀镍金镀层厚度是PCB产品可靠性的关键指标,文章从插头镀金线实际生产需求出发,运用法拉第定律和多元函数进行数学推导,得出一个普遍适用于插头镀金线镀层厚度理论计算模型。在理论计算模型的基础上进行多次试验分别得出电镀镍和电镀金的电流效率,并对实际镀层厚度计算模型的有效性进行重复试验验证。试验结果表明,我们可以得出一个合理的镀层厚度计算模型以指导插头镀金线实际生产。%The electrodeposited coatings thickness of Nickel and Gold is the crucial quality index for PCB manufacture reliability. The paper makes use of Faraday Law and function of many variables to deduce an applicable theoretical calculational model for the electrodeposited coatings thickness of Nickel and Gold about Plug Gold plating line. We carried out so many experiments based on the theoretical calculational model that the current efifciencies about electroplating Nickel and Gold are worked out. We veriifed the effectiveness of the actual calculational model by repeated experiments. The results shows that we can get a logical calculational model to the electrodeposited coatings thickness for Plug Gold plating line in practice.

  19. 钢板压力淬火生产线控制系统%Control System of Armor Plate Press Quenching Production Line

    Institute of Scientific and Technical Information of China (English)

    王以琦; 施建华; 彭光宇; 王克伟; 马丹; 李超

    2012-01-01

    A set of control system was developed, which realized all kinds of precise control to press quenching produc-tion line, and met the requirement s of process of a variety of production. The production line requires high precise control, and the temperature levelling of furnace can reach between -10℃ and +10℃ , it is rarely seen in domestic heat treatment furnace. Moreover, it has the characteristics such as automation, high producing efficiency, low energy costs, good operat-ing environment, low intensity of labour and so on, the level of technology are advanced compared with other congeneric production lines in domestic. After large -scale production, the results showed that all kinds of production showed high quality.%开发了一套控制系统,实现了对压力淬火生产线的各种精确控制,满足了多品种工艺生产要求.该控制系统控制精度高,可保证生产线中燃气辊底炉炉温均匀性达到±10℃以内.经实践验证,该生产线生产效率高,能耗小,操作环境好,劳动强度低,技术水平在国内同类生产线中居领先地位.规模生产结果表明,各品种规格的产品均满足质量要求.

  20. INFLUENCE ON THE DISTRIBUTION OF PHOSPHORUS BY ADDING AL-CONTAINING COMPONENT IN SLUDGE MELTING PROCESS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IntroductionThe sludge is generally discarded and babied afterbeing separated from the waStewst6r in the sewagetreatment plan. For the steadily increasing wastesludge dischop and the concerns of environmentprotection, it is essential tO treat and disPOse sewagesludge efficiently and safely in line with progressiveimprovements in sewage facilities. A sewage sludgemelting process which enables the sludge tO be treatedeffectively and safely haS been developed by OsakaGas Co., Ltd.[l] The deW8t6red sludge cake ...

  1. Create Your Plate

    Medline Plus

    Full Text Available ... A A A Listen En Español Create Your Plate Create Your Plate is a simple and effective ... and that your options are endless. Create Your Plate! Click on the plate sections below to add ...

  2. Enhanced sludge washing evaluation plan

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices.

  3. Leaching of metals on stabilization of metal sludge using cement based materials

    Institute of Scientific and Technical Information of China (English)

    Carmalin Sophia A; K. Swaminathan

    2005-01-01

    Toxicity characteristic leaching procedure(TCLP) of zinc plating sludge was carried out to assess the leaching potential of the sludge and the leachates were analyzed for heavy metals. The concentration of zinc, chromium, and lead in the leachate were 371.5mg/L, 1.95 mg/L and 1.99 mg/L respectively. Solidification of zinc sludge was carried out using four different binder systems consisting of cement mortar, fly ash, clay and lime and cured for 28 d. The ratio of sludge added varied from 60% to 80% by volume. The solidified products were tested for metal fixing efficiency and physical strength. It was observed that the volume of sludge added that resulted in maximum metal stabilization was 60% for all the combinations, above which the metal fixation efficiency decreased resulting in high values of zinc in the leachate. Addition of 5% sodium silicate enhanced the chemical fixation of metals in all the binder systems. Among the four fixing agents studied, mixture of fly ash: lime, and cement mortar: lime stabilized zinc and other metals in the sludge effectively than other combinations. Addition of lime increased the stabilization of zinc whereas cement mortar increased the strength of the solidified product.

  4. Fractionation and business potential from sludge - Pafrak

    Energy Technology Data Exchange (ETDEWEB)

    Kylloenen, H.; Groenroos, A.; Pirkonen, P. (VTT Tecchnical Research Centre of Finland, Jyvaeskylae (Finland)), Email: hanna.kyllonen@vtt.fi; Maekinen, L.; Aemmaelae, A.; Niinimaeki, J. (Univ. of Oulu (Finland)), Email: liisa.makinen@oulu.fi

    2010-10-15

    Wastewater sludges contain valuable components which can be recycled and converted to secondary raw material. High water content of sludge can hinder the further processing. Dry solids content of waste activated sludge after dewatering can be as low as 12-20% and even lower for tertiary sludge. This research aimed with better knowledge of sludge and fractionation to generate potential business ideas, which could lead to new sludge based products and services in national and international markets already in this project or in separate development projects. Primary, waste activated, tertiary and deinking sludge from pulp and paper industry and municipal waste activated sludge were the suspensions to be studied. Basic properties of these sludges have been determined by large number of analysing methods. Wood based components and chemical elements have been determined to clarify the raw material potential for biorefineries. Conventional fractionation techniques (decanter centrifuge, hydrocyclone, belt filter press and sieve bend) have been used to see how the sludge can be fractionated. Correlations of wood based components and dewatering properties have been studied especially for the waste activated sludge. The effects of wood based filter aids were studied on the dewatering properties of waste activated sludge. State of the art has been drawn up about the current utilisation of wastewater sludge. (orig.)

  5. Influence of magnetic field on activity of given anaerobic sludge.

    Science.gov (United States)

    Xu, Y B; Duan, X J; Yan, J N; Du, Y Y; Sun, S Y

    2009-11-01

    Two modes of magnetic fields were applied in the Cr(6+) removal sludge reactors containing two predominated strains--Bacillus sp. and Brevibacillus sp., respectively. The magnetic field mode I* of 0-4.5 or 0-14 mT between pieces was obtained by setting the magnetic pieces with the surface magnetic density of 0-6 or 0-20 mT into the reactor, and the magnetic field mode II* of 6, 20, or 40 mT on the return line was obtained by controlling the working distance of the permanent magnet outside the sludge return line. The effects of different magnetic fields on the activity of the given anaerobic sludge were studied by comparing with the control (absent of magnetic field). The results showed that the magnetic field of 0-4 mT improved the activity of given sludge most effectively, U(max) CH(4) (the peak methane-producing rate) and the methane producing volume per gCOD(Cr) reached 64.3 mlCH(4)/gVSS.d and 124 mlCH(4)/gCOD(Cr), which increased by 20.6 and 70.7%, respectively, compared with the control. And the magnetic field of 20 mT took second place. It could be concluded that the input of some magnetic field could improve the activity of anaerobic sludge by increasing the transformation efficiency of COD(Cr) matters to methane, and the total organic wastage did not increase.

  6. Microbiological aspects of granular methanogenic sludge

    NARCIS (Netherlands)

    Dolfing, J.

    1987-01-01

    The settling characteristics of anaerobic sludge are enhanced by the formation of microbial conglomerates. Various types of conglomerates having different structures, were distinguished in the present study, viz. granules, pellets and flocs (chapter 1). Granular methanogenic sludge, often

  7. Technology Assessment Report: Aqueous Sludge Gasification Technologies

    Science.gov (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...

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

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  9. Sludge Water Characteristics Under Different Separation Methods from a Membrane Bioreactor

    KAUST Repository

    Wei, Chunhai

    2013-11-22

    The concept of sludge water was proposed to integrate the relative terminologies and its characteristics under different separation methods from a membrane bioreactor (MBR) were investigated in this study. Based on chemical oxygen demand (COD) and three-dimensional fluorescence excitation-emission matrix (F-EEM), and compared with the control (gravitational sedimentation), some suspended particulate organics or biopolymer clusters (mainly proteins) were released from sludge flocs into the supernatant after centrifugation under low to middle centrifugal forces (10-4000 g) and then aggregated into a pellet under high centrifugal forces (10000-20000 g). Filtration (1.2 μm glass fiber filter) produced sludge water with a lower biopolymers concentration than the control (gravitational sedimentation followed by filtration) due to cake layer formation during filtration. As for centrifugation followed by filtration, low to middle centrifugal forces did not significantly affect sludge water characteristics but high centrifugal forces reduced the concentrations of some proteins in sludge water from advanced analytical protocols including F-EEM and liquid chromatography with on-line organic carbon detection (LC-OCD), demonstrating a low to middle centrifugal force suitable for MBR sludge water separation. From LC-OCD, the main fractions of sludge water were humic substances and building blocks, low molecular weight neutrals and biopolymers (mainly proteins rather than polysaccharides). Supplemental materials are available for this article. Go to the publisher\\'s online edition of Separation Science and Technology to view the supplemental file. © 2013 Copyright Taylor and Francis Group, LLC.

  10. Cr26MoWVTiRE Development and Application of Cast Alloy Iron Chute Lining Plate%Cr26MoWVTiRE合金铸铁溜槽衬板开发与应用

    Institute of Scientific and Technical Information of China (English)

    李固成

    2013-01-01

    针对钢铁企业高炉布料溜槽衬板所处的恶劣作业环境,研究开发出具有一定耐高温、耐腐蚀性的Cr26MoWVTiRE高铬合金铸铁材料.在经1 020,~1 050℃淬火+320~520℃回火,材料的硬度达到HRC 60~62,冲击韧度ak>5 J/cm2.Mo、W合金和V、Ti等强碳化物元素的复合加入,提高了溜槽衬板的硬韧性、红硬性和高耐磨性,衬板实际使用寿命超过18个月.与镶铸硬质合金溜槽衬板相比,该衬板具有生产工艺简单、成本低、性价比高等特点,有一定推广应用价值.%Aiming at the bad working environment of distributing chute for iron and steel enterprises furnace,Cr26MoWVTiRE high chromium alloy cast iron material was developed,which has high temperature resistance,corrosion resistance.After 1 020-1 050 ℃ quenching and 320-520 ℃ tempering,the material hardness reached HRC 60-62,and impact toughness ak 5 J/cm2.The hardness and toughness,red hardness,high-wearing feature were improved by composite addition ofMo,W alloy and V,Ti and other strong carbide elements,and the service life of lining plate was more than 18 months.Compared to the cast-in hard alloy chute lining plate,it has the advantages such as simple production process,low cost,high performance/cast ratio,and deserves popularization.

  11. The Optimization Program of Steel Plate Feeding Device for LASW Pipe Production Line%直缝埋弧焊管生产线钢板上料装置优选方案

    Institute of Scientific and Technical Information of China (English)

    李钢; 张增全; 韩保材; 汤跃先; 汤圣先

    2015-01-01

    In this article, it described the main structure and constitute of 3 kinds of commonly used feeding device of JCOE/UOE LSAW pipe production line, including the combined converyor of roller and chain, chain conveyor and vacuum suction cups hanging conveyer, and compared the main structure and constitute with several aspects, such as equipment structure and operation, operation and maintenance workload, equipment investment, installed capacity, production running cost, plate scratch, etc. The results indicated that vacuum suction cups hanging conveyer device is with some advantages, such as simple structure, easy operation, low workload for operation and maintenance, small investment, small installed capacity, low production running cost, and production rhythm can completely meet the design requirements, which is the best optimization program for LASW pipe production line steel plate feeding device.%对JCOE/UOE直缝埋弧焊管生产线上通常采用的三种上料装置, 即平辊和链条组合输送装置、 链条输送装置以及真空吸盘吊输送装置的主要结构和组成进行了描述, 并从设备结构与操作、运行与维护工作量、 设备投资、 装机容量、 生产运行成本、 钢板划伤等主要方面进行了对比. 结果表明, 采用真空吸盘吊输送装置具有设备结构简单、 操作方便、 运行与维护的工作量相对较低、 资金投入相对较少、 装机容量小、 生产运行成本低、 生产节奏完全能满足设计要求等优点, 是直缝埋弧焊管生产线钢板上料的最佳优选方案.

  12. Getting on with persistent pollutants: Decreasing trends of perfluoroalkyl acids (PFAAs) in sewage sludge.

    Science.gov (United States)

    Ulrich, Hanna; Freier, Korbinian P; Gierig, Michael

    2016-10-01

    Sewage sludge can be a relevant source of perfluoroalkyl acids (PFAAs) for the environment. In order to reduce emissions from this source, Bavarian authorities enforced in 2008 an analysis of PFAAs from sewage sludge derived from municipal wastewater treatment plants (WWTPs). 4981 sludge samples from 1165 different WWTPs were analyzed between 2008 and 2013 for 11 PFAAs compounds. During this period, 71 WWTPs exceeded the precautionary limit of 125 μg kg(-1) dm of total PFAAs in sludge samples at least once with a decreasing tendency. The yearly exceedances of the investigated WWTPs decreased from 6% in 2008 to 0.8% in 2013. At the same time, the percentage of uncontaminated WWTPs increased from 33% to 65%. Perfluorooctane sulfonic acid (PFOS) was the predominant compound found in 41% of all sludge samples. Perfluorodecanoic acid (PFDA) was detected in 19% and Perfluorooctanoic acid (PFOA) in 7%. Very high PFAAs concentrations (>500 μg kg(-1) dm) in sewage sludge were generally caused by firefighting foams containing PFAAs or emissions from PFAAs-using industries including metal plating, textile, leather or paper industries. Trend analyses of the six year period show that PFAAs contamination in sewage sludge clearly decreased for 47% of the WWTPs. However, for 16% of the WWTPs an increasing trend was detected, even though the concentration levels were below the precautionary limit. During the six years of investigation the load of total PFAAs in sewage sludge was reduced by more than 90%, from 17 t a(-1) in 2008 to 1.5 t a(-1) in 2013.

  13. Activated sludge process based on artificial neural network

    Institute of Scientific and Technical Information of China (English)

    张文艺; 蔡建安

    2002-01-01

    Considering the difficulty of creating water quality model for activated sludge system, a typical BP artificial neural network model has been established to simulate the operation of a waste water treatment facilities. The comparison of prediction results with the on-spot measurements shows the model, the model is accurate and this model can also be used to realize intelligentized on-line control of the wastewater processing process.

  14. Hybrid Sludge Modeling in Water Treatment Processes

    OpenAIRE

    Brenda, Marian

    2015-01-01

    Sludge occurs in many waste water and drinking water treatment processes. The numeric modeling of sludge is therefore crucial for developing and optimizing water treatment processes. Numeric single-phase sludge models mainly include settling and viscoplastic behavior. Even though many investigators emphasize the importance of modeling the rheology of sludge for good simulation results, it is difficult to measure, because of settling and the viscoplastic behavior. In this thesis, a new method ...

  15. Fractionation and business potential from sludge - Pafrak

    Energy Technology Data Exchange (ETDEWEB)

    Kylloenen, H.; Groenroos, A.; Pirkonen, P. (VTT Technical Research Centre of Finland, Jyvaeskylae (Finland)), email: hanna.kyllonen@vtt.fi; Maekinen, L.; Suopajaervi, T.; Niinimaeki, J. (Univ. of Oulu (Finland)), email: liisa.makinen@oulu.fi

    2009-10-15

    Wastewater sludge contains valuable components which can be recycled and converted to secondary raw material. High water content of sludge can hinder the further processing. Dry solids content of waste activated sludge after dewatering can be as low as 12-20% and even lower for tertiary sludge. This research aims with better knowledge of sludge and fractination to generate potential business ideas, which could lead to new sludge based products and services in national and international markets already in this project or in separate development projects. Primary, waste activated, tertiary and deinking sludge from pulp and paper industry and municipal waste activated sludge have been the suspensions to be studied. Basic properties of these sludges have been determined by large number of analysing methods. Wood based components and chemical elements have been determined to clarify the raw material potential for biorefineries. Correlations of wood based components and dewatering properties, which is one of the key topics, have been studied especially for the waste activated sludge. Conventional fractionation techniques (decanter centrifuge, hydro cyclone, belt filter press and sieve bend) have been used to see how the sludge can be fractionated. State of the art has been drawn up about the current utilisation of wastewater sludge. (orig.)

  16. Heavy metals precipitation in sewage sludge

    NARCIS (Netherlands)

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

    2005-01-01

    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

  17. Paper Sludge Reuse in Lightweight Aggregates Manufacturing.

    Science.gov (United States)

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

    2016-10-27

    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.

  18. Supplementary information on K-Basin sludges

    Energy Technology Data Exchange (ETDEWEB)

    MAKENAS, B.J.

    1999-03-15

    Three previous documents in this series have been published covering the analysis of: K East Basin Floor and Pit Sludge, K East Basin Canister Sludge, and K West Basin Canister Sludge. Since their publication, additional data have been acquired and analyses performed. It is the purpose of this volume to summarize the additional insights gained in the interim time period.

  19. Fractionation and business potential from sludge (Pafrak)

    Energy Technology Data Exchange (ETDEWEB)

    Pirkonen, P.; Kylloenen, H. (VTT Technical Research Centre of Finland, Jyvaeskylae (Finland)); Niinimaeki, J.; Oksanen, J. (Univ. of Oulu (Finland))

    2008-07-01

    Wastewater sludge contains valuable components which can be recycled and converted to secondary raw material. High water content of sludge can hinder the further processing. Dry solids content of waste activated sludge after dewatering can be as low as 12-20% and even lower for tertiary sludge. This research aims with better knowledge of sludge and fractionation to generation of potential business ideas which could lead to new sludge based products and services in national and international markets already in this project or in separate development projects. Municipal waste activated sludge and deinking, primary, waste activated and tertiary sludge from pulp and paper industry are the suspensions to be studied. Basic properties of these sludges have been determined by large number of analysing methods. Dewatering properties, which are one of the key topics, have been studied with a novel flocculation/filtration device. Conventional fractionation equipment (decanter centrifuge, hydrocyclone. filter belt press and sieve bend) have been used to see how the sludge could be fractionated. State of the art has been drawn up about the current utilisation of wastewater sludge. One of the key issues in future research is how to affect the binding forces between different substances in sludge. (orig.)

  20. Heavy metals precipitation in sewage sludge

    NARCIS (Netherlands)

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

    2005-01-01

    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 adv

  1. 40 CFR 61.54 - Sludge sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge...

  2. Technology Assessment Report - Aqueous Sludge Gasification Technologies

    Science.gov (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...

  3. Advantages of thermal processes to reduce the amounts of sludge; Interet des procedes thermiques dans la problematique de la reduction et/ou de l'elimination des boues?

    Energy Technology Data Exchange (ETDEWEB)

    Cretenot, D. [Vivendi Water System, 94 - Saint-Maurice (France); Chauzy, J.; Fernandes, P.; Patria, L. [Anjou Recherche, 78 - Maisons-Laffite (France)

    2003-02-01

    All the actors in the water field have to face the fate of sludge generated by wastewater treatment. The challenge they have to take up is not only on the good quality of the final effluent but also on the by-products treatment performance. Reduction, stabilization and pasteurization are the key-words in the present trend of sludge treatment., There are many technologies that reduce the final volume of sludge by lowering their dry solids concentration, but only the treatment lines with thermal processes can both reduce the amounts of sludge generated, and also issue sludge that answers to more and more stringent constraints on sanitary quality.

  4. Comparison of membrane fouling during short-term filtration of aerobic granular sludge and activated sludge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier Transform Infrared (FTIR) spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.

  5. Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

    Science.gov (United States)

    Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

    2010-01-01

    The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

  6. Automatic Plating of Single-line Diagrams for Power Transmission Network Online Theoretical Line Loss Analysis Based on Ant Colony Algorithm%基于蚁群的在线理论线损分析用输电网单线图自动布局

    Institute of Scientific and Technical Information of China (English)

    卢志刚; 李学平

    2011-01-01

    输电网在线理论线损分析有时需要根据公共信息模型自动生成电网单线图,此时必须实现电网布局的自动生成;对于大电网,需要较短的求解时间。自动布局一般存在容易陷入局部最优解和求解时间长2种问题。文中将输电网单线图布局转化为二次分配问题,并且采用蚁群算法和3-opt优化,解决了以上问题。考虑可能的并行计算扩展,算法忽略各蚂蚁间的信息素更新,选择局部最优解和全局最优解更新信息素。仿真结果布局清晰,求解时间短,能够满足输电网在线理论线损分析要求。%To meet occasional needs for automatic generation of power network single-line diagrams from the common information model(CIM) in power transmission network online theoretical line loss analysis,it is necessary for the big power network to automatically generate its network layout and ask for rather short solving-time.In view of the problems with automatic plating,namely,local optimum and the long solving time,the plating of single-line diagrams for power transmission networks is transformed into a quadratic assignment problem using the ant colony algorithm with 3-opt optimization.By taking into consideration potential parallel computation,local optimum and global optimum are chosen to update the pheromone while ignoring pheromone updating between ants.Simulation results show that the requirement of the power transmission network online theoretical line loss analysis is met by clear layout and short solving time. This work is supported by National Natural Science Foundation of China(No.61071201) and Natural Science Foundation of Hebei Province(No.F2010001319).

  7. Plate shell structures - statics and stability

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2008-01-01

    This paper describes the basic structural system, statics and spatial stability of plate shells. The structural system can be considered as a single layer of planar elements, where each element only transfers in-plane (membrane) forces to its neighbouring elements. External out-of-plane loads...... are carried into the structure as in-plane forces by plate action in each element. These in-plane forces are then carried through the plate structure to the supports as in-plane forces by membrane action. The consequence is that the spatial stability of the structure can be simply analysed by considering...... the plate system as only subject to in-plane loads. The stability of such systems is based on the fact that each plane element is held fixed in space by three fixed support lines and that these support lines can be provided by three plane neighbour elements. This means that the spatial stability of a plate...

  8. Fermentation and chemical treatment of pulp and paper mill sludge

    Science.gov (United States)

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

    2014-12-02

    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.

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

    DEFF Research Database (Denmark)

    Klinge, C; Gejlsbjerg, B; Ekelund, Flemming

    2001-01-01

    . 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...

  10. Excitation and Characterization of Chladni Plate Patterns

    Science.gov (United States)

    Bourke, Shannon; Behringer, Ernest

    2011-04-01

    When a thin metal plate with a small amount of sand on it is made to vibrate, aesthetically pleasing sand patterns can form along the nodal lines of the plate. These symmetric patterns are called Chladni Patterns. Students taking PHY 101 Physical Science in the Arts at Eastern Michigan University create these patterns by pulling a violin bow across the edge of a plate, or by using a mechanical oscillator to drive the center of a plate. These two methods only allow a small subset of all possible points on the plate to be excited. We designed and built an electronic device that allows its user to excite the plate at any point. We present patterns created with this electronic device and other methods, and describe ways to model the observed patterns.

  11. Performance of wastewater sludge ecological stabilization

    Institute of Scientific and Technical Information of China (English)

    CUI Yubo; SUN Tieheng; ZHAO Lihui; JIANG Tingliang; ZHANG Liping

    2008-01-01

    In this article,wastewater sludge ecological stabilization (WWSES) was presented for sludge dewatering,mineralization,and stabilization,as well as for percolate treatment.Two years of pilot scale experimental results indicated that sludge volatile solid,triphenylteuazolium chloride (TTC)-dehydrogenase aetivity(DHA),and moisture content as indicators showed the process and degree of sludge stabilization.The observation on dewatering process showed that dried sludge reached a content of 20%-50% total solid after two years of system operation.Sludge TTC-DHA in the first year was obviously lower than that of the second year,and TTC-DHA tended to decrease with an increase in the drying time of the sludge.Total nitrogen,total phosphorus,and organic contents of sludge decreased gradually from the top to the bottom of dried sludge layer.In comparison with natural stands on stands treated with sewage sludge,individual shoot was significantly higher,and coarse protein,coarse fat,and coarse fiber contents in reed roots,stems,and leaves in the system were higher than that of wild reed,especially coarse protein contents of reed roots in the system(7.38%)were obviously higher than that of wild reeds(3.29%).

  12. Application of Shape Lock-on Method in Plate Rolling

    Institute of Scientific and Technical Information of China (English)

    HU Xian-lei; WANG Jun; WANG Zhao-dong; LIU Xiang-hua; WANG Guo-dong

    2004-01-01

    AGC system can improve the plate gauge precision, and damage the plate shape if the shape control loop is left quite open. This damage will cause wave during rolling wide-thin plate. A control strategy named shape lock-on method is afforded for plate shape control. This method requires APC instead of AGC at last one or two passes during rolling wide-thin plate. Approved by theory and on-line application, this method is good for the plate shape and crown control with small effect on gauge control.

  13. The Fungi in Bio-sludge Composts and Its Metabolites Relate with PGPR Effect

    OpenAIRE

    森本, 正則; 松本, 朋子; 駒井, 功一郎

    2004-01-01

    [Synopsis] Sometime, the compost products made from bio-sludge and containing paper strips, showed plant growth promoting effect in the field. We have evaluated to separating various fungi from biosludge compost that have PGPR (Plant Growth Promoting Rhizobacteria) effect against some cropsinoculating test into the incubation soil. Test fungi separated from the compost using by multiple dilution method and colonization on the PDA agar plate. And, the surface of autoclaved oat serials kept eac...

  14. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  15. STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

  16. Leachability of heavy metals from solidified sludge

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuYuan; WANG Bao; DONG XingLing; FENG Lei; FAN ZhiMing

    2009-01-01

    Solidified sludge undergoes progressive depletion of the alkalinity materials under natural weathering condition and releases out of heavy metals. The leaching of heavy metals from solidified sewage sludge was studied by acid neutralization capacity (ANC) test and flow-through leaching test. The results of ANC test showed that heavy metals release at high concentration when the pH of extract lowers than 6. The disintegration of solidified sludge and the transformation of heavy metals are the main reasons for the resolubilisation of contaminants. Flow-through leaching test indicated that leaching of heavy metals from solidified sludge occurs in a slow way. A mathematical model has been developed to predict the stabilization time of heavy metals in solidified sludge. The research results showed that decreasing hydraulic conductivity is more important than cement addition for controlling the release of heavy metals from solidified sludge.

  17. Sludge based Bacillus thuringiensis biopesticides: viscosity impacts.

    Science.gov (United States)

    Brar, S K; Verma, M; Tyagi, R D; Valéro, J R; Surampalli, R Y

    2005-08-01

    Viscosity studies were performed on raw, pre-treated (sterilised and thermal alkaline hydrolysed or both types of treatment) and Bacillus thuringiensis (Bt) fermented sludges at different solids concentration (10-40 g/L) for production of biopesticides. Correlations were established among rheological parameter (viscosity), solids (total and dissolved) concentration and entomotoxicity (Tx) of Bt fermented sludges. Exponential and power laws were preferentially followed by hydrolysed fermented compared to raw fermented sludge. Soluble chemical oxygen demand variation corroborated with increase in dissolved solids concentration on pre-treatments, contributing to changes in viscosity. Moreover, Tx was higher for hydrolysed fermented sludge in comparison to raw fermented sludge owing to increased availability of nutrients and lower viscosity that improved oxygen transfer. The shake flask results were reproducible in fermenter. This study will have major impact on selecting fermentation, harvesting and formulation techniques of Bt fermented sludges for biopesticide production.

  18. Changes in soil microbial functional diversity and biochemical characteristics of tree peony with amendment of sewage sludge compost.

    Science.gov (United States)

    Huang, Xiangdong; Xue, Dong; Xue, Lian

    2015-08-01

    A greenhouse experiment was conducted to investigate the impact of sewage sludge compost application on functional diversity of soil microbial communities, based on carbon source utilization, and biochemical characteristics of tree peony (Paeonia suffruticosa). Functional diversity was estimated with incubations in Biolog EcoPlates and well color development was used as the functional trait for carbon source utilization. The average well color development and Shannon index based on the carbon source utilization pattern in Biolog EcoPlates significantly increased with the increasing sludge compost application in the range of 0-45%, with a decreasing trend above 45%. Principal component analysis of carbon source utilization pattern showed that sludge compost application stimulated the utilization rate of D-cellobiose and α-D-lactose, while the utilization rate of β-methyl-D-glucoside, L-asparagine, L-serine, α-cyclodextrin, γ-hydroxybutyric acid, and itaconic acid gradually increased up to a sludge compost amendment dosage of 45% and then decreased above 45%. The chlorophyll content, antioxidase (superoxide dismutase, catalase, and peroxidase) activities, plant height, flower diameter, and flower numbers per plant of tree peony increased significantly with sludge compost dosage, reaching a peak value at 45 %, and then decreased with the exception that activity of superoxide dismutase and catalase did not vary significantly.

  19. [Isolation of filamentous fungi capable of enhancing sludge dewaterability and study of mechanisms responsible for the sludge dewaterability enhancement].

    Science.gov (United States)

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

    2015-02-01

    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.

  20. Emission characteristics of co-combustion of sewage sludge with olive cake and lignite coal in a circulating fluidized bed.

    Science.gov (United States)

    Toraman, Oner Yusuf; Topal, Hüseyin; Bayat, Oktay; Atimtay, Aysel T

    2004-01-01

    In this study, a circulating fluidized bed (CFB) of 125 mm diameter and 1800mm height was used to find the combustion characteristics of sewage sludge (SS) produced in Turkey. Sludge + olive cake, and sludge + lignite coal mixtures were burned separately. Various sludge-to-lignite coal and sludge-to-olive cake ratios (5/95, 10/90, 15/85, 20/80) were tried. On-line concentrations of major components (O2, SO2, CO2, CO, NOx, CmHn) were measured in the flue gas, as well as temperature and pressure distributions along the bed. Combustion efficiencies of sludge + olive cake and sludge + lignite coal mixtures were calculated, and the optimum conditions for operating parameters were discussed. The results have shown that the combustion mainly takes place in the upper regions of the main column where the temperature reaches 900 degrees C. SS + Coal burn in the CFB with an efficiency of 95.14% to 96.18%, which is considered to be quite good. When burning sludge mixed with olive cake, appreciable amounts of CO and unburned hydrocarbons are formed and the combustion efficiency drops to 92.93%. CO and CmHn emissions are lower when lignite coal is mixed with various amounts of SS than the emissions when the coal is burned alone. As the %SS is increased in the fuel mixture, the SO2 emission decreases. NOx emissions are slightly higher. When burning sludge mixed with olive cake, SO2 and NOx emissions are slightly higher. CO and CmHn emissions decrease sharply when SS is mixed with 5%wt. olive cake. With increasing sludge ratio these emissions increase due to the unburned hydrocarbons. As a result of this study, it is believed that SS can be burned effectively in a CFBC together with other fuels, especially with olive cake (OC). OC will be a good additive fuel for the combustion of lower quality fuels.

  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.

    1977-11-01

    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. Using Boiling for Treating Waste Activated Sludge

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this work we investigated the feasibility of using short time, low superheat boiling to treat biological sludge. The treated sludge exhibited reduced filterability and enhanced settleability. The boiling treatment released a large amount of extra-cellular polymers (ECPs) from the solid phase and reduced the microbial density levels of the total coliform bacteria and the heterotrophic bacteria. A diluted sludge is preferable for its high degree of organic hydrolysis and sufficient reduction in microbial density levels.

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

    DEFF Research Database (Denmark)

    Hörsing, Maritha; Ledin, Anna; Grabic, Roman

    2011-01-01

    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...

  4. Sewage sludge as a biomass energy source

    Directory of Open Access Journals (Sweden)

    Pavel Kolat

    2013-01-01

    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. Treatment of sewage sludge using electrokinetic geosynthetics.

    Science.gov (United States)

    Glendinning, Stephanie; Lamont-Black, John; Jones, Colin J F P

    2007-01-31

    The treatment and disposal of sewage sludge is one of the most problematical issues affecting wastewater treatment in the developed world. The traditional outlets for sewage sludge are to spread it on agricultural land, or to form a cake for deposit to landfill or incineration. In order to create a sludge cake, water must be removed. Existing dewatering technology based on pressure can only remove a very limited amount of this water because of the way in which water is bound to the sludge particles or flocs. Several researchers have shown that electrokinetic dewatering of sludge is more efficient than conventional hydraulically driven methods. This involves the application of a dc voltage across the sludge, driving water under an electrical gradient from positive (anode) electrode to negative (cathode) electrode. However, there have been several reasons why this technique has not been adopted in practice, not least because the, normally metallic, anode rapidly dissolves due to the acidic environment created by the electrolysis of water. This paper will describe experimentation using electrokinetic geosynthetics (EKG): polymer-based materials containing conducting elements. These have been used to minimise the problem of electrode corrosion and create a sludge treatment system that can produce dry solids contents in excess of 30%. It will suggest different options for the treatment of sludges both in situ in sludge lagoons and windrows, and ex situ as a treatment process.

  6. Process of Waste Sludge Facultative Metabolism

    Institute of Scientific and Technical Information of China (English)

    李茵

    2001-01-01

    Laboratory- scale experiments were conducted to determine new technology of waste sludge facultative metabolism . 10-L laboratory-scale facultative reactors were operated during 24-hour sludge residence time (SRT) and in room temperature . Results show that the organic matter in waste sludge after hydrolysis acidification will be reduced by 75.39%, the removal rate of CODer above 85% . Advantage of the process is hydrolysis-acidification in ambient air temperature as there is no need for facilities to be sealed or heated. In addition, the sludge will be recycled into the wastewater treatment system and finally towards zero-discharge.

  7. Height Adjustment Technology for Induction Plate of Linear Motor in Line%直线电机线路感应板高度调整技术探讨

    Institute of Scientific and Technical Information of China (English)

    席雷

    2012-01-01

    感应板是直线电机线路中的重要设备,文章对感应板高度调整工作的特点进行了介绍,并进一步分析了感应板高度变化的原因,在此基础上提出了感应板高度调整工作的若干建议。%The induction plate is an important component of linear motor, the paper describes characteristics of the induction plate height adjustment work, and further analyzes the reasons of induction plate height changes. Based on it, recommendations are made on the induction plate height adjustment work.

  8. Convective drying of sludge cake

    Science.gov (United States)

    Chen, Jianbo; Peng, Xiaofeng; Xue, Yuan; Lee, Duujong; Chu, Chingping

    2002-08-01

    This paper presented an experimental study on convective drying of waste water sludge collected from Beijing GaoBeiDian Sewage Treatment Plant, particularly on the correlation between the observed shrinkage dynamics of sludge cake and the drying curve. During the initial stage of drying the process resembles to that of a particulate bed, in which moisture diffuses and evaporates at the upper surface. Conventional drying theory assuming a diffusion-evaporating front interprets this period of drying. Consequently, owing to the very large shrinkage ratio of the dried cake, cracks emerges and propagates on and within the cake body, whence inducing evaporating channel that facilitates the water removal. This occurrence compensates the reduction of surface area for evaporation, whence extending the constant-rate period during the test. Afterwards, the cracks meet with each other and form isolated cake piles, while the subsequent drying occur mainly within these piles and the conventional theory fails. The transition between the drying on a plain cake layer and that on the isolated piles demonstrates the need to adopt distinct descriptions on these two regimes of drying for the sludge cake.

  9. 电晕线串并联的脉冲电晕放电特性%Pulse Corona Discharge Characteristics of the Line-to-plate Reactor with Series and Parallel Corona Wire

    Institute of Scientific and Technical Information of China (English)

    何正浩; 李劲

    2001-01-01

    The V-A characteristics of nanosecond pulse corona discharge with different corona wire length in series and parallel in the line-to-plate pulse corona discharge reactor is measured.It investigates the different features of the pulse corona discharge while the corona wires are connected in series and parallel. It is known from the study that the V-A characteristics of nanosecond pulse corona discharge trends to rise as exponential function. The corona currents with the wire in series increase as logarithmic function with the increase of the corona wire. But the corona currents with the wire in parallel increase as linear function with the increase of the corona wire. The results suggest that the corona wires is better to be connected in parallel in practical design for getting high corona discharge efficiency and the corona wire shouldn’t be long.%在线板结构脉冲电晕放电试验模型上,测试了不同长度电晕线串并联时的ns脉冲电晕放电伏安特性,研究了电晕线串并联时脉冲电晕放电的不同特点。研究表明ns脉冲电晕放电伏安特性呈指数函数上升趋势,串联电晕线的电晕电流随其长度的增长为自然对数函数上升趋势,并联电晕线的电晕 电流随其长度的增长为线形函数上升趋势。根据研究,实际设计脉冲电晕放电反应器时,为提高反应器效率,多根电晕线应并联而不宜串联,且电晕线不宜过长。

  10. Continuum Mechanics of Beam and Plate Flexure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    This text has been written and used during the spring of 1995 for a course on flexural mechanics of beams and plates at Aalborg University. The idea has been to concentrate on basic principles of the theories, which are of importance to the modern structural engineer. Today's structural engineer...... must be acquainted with the classic beam and plate theories, when reading manuals and using modern software tools such as the finite element method. Each chapter includes supplementary theory and derivations enabling consultation of the notes also at a later stage of study. A preliminary chapter...... analysis of beam structures is presented and includes both upper and lower-bound solution techniques. The remaining chapters are devoted to plates. The classic elastic plate theories are presented. The plastic yield line theory for plates is presented including both upper and lower-bound techniques...

  11. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation.

    Science.gov (United States)

    Ekstrand, Eva-Maria; Karlsson, Marielle; Truong, Xu-Bin; Björn, Annika; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2016-10-01

    Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for the biogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibre sludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation. Two lab-scale reactors (4L) were run for 800days, one on fibre sludge (R1), and the other on fibre sludge and activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, the Ca:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abated by short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robust conditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4g volatile solids (VS)L(-1)day(-1), a hydraulic retention time of 4days and a methane production of 230±10NmL per g VS.

  12. Effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions.

    Science.gov (United States)

    Lv, Dong; Zhu, Tianle; Liu, Runwei; Lv, Qingzhi; Sun, Ye; Wang, Hongmei; Liu, Yu; Zhang, Fan

    2016-09-01

    The effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions were systematically investigated in a cement production line in Beijing. The results show that co-processing the sewage sludge was helpful to reduce NOx emission, which primarily depends on the NH3 amount released from the sewage sludge. Meanwhile, NOx and NH3 concentrations in the flue gas have a negative correlation, and the contribution of feeding the sewage sludge to NOx removal decreased with the increase of injection amount of ammonia water in the SNCR system. Therefore, it is suggested that the injection amount of ammonia water in SNCR system may reduce to cut down the operating costs during co-processing the sewage sludge in cement kiln. In addition, the emission of total PAHs seems to increase with the increased amount of the sewage sludge feeding to the cement kiln. However, the distributions of PAHs were barely changed, and lower molecular weight PAHs were mainly distributed in gaseous phase, accounted for the major portion of PAHs when co-processing sewage sludge in cement kiln.

  13. Partial ozonation of activated sludge to reduce excess sludge, improve denitrification and control scumming and bulking

    Energy Technology Data Exchange (ETDEWEB)

    Boehler, Marc; Siegrist, Hansruedi

    2003-07-01

    Disposal of sewage sludge is forbidden and agricultural use of stabilized sludge will be banned in 2005 in Switzerland. The sludge has to be dewatered, dried, Incinerated and the ashes disposed in landfills. These processes are cost intensive and lead also to the loss of valuable phosphate resources incorporated in the sludge ash. The implementation of processes that could reduce excess sludge production and recycle phosphate is therefore recommended. Partial ozonation of the return sludge of an activated sludge system reduces significantly excess sludge production, improves settling properties of the sludge and reduces bulking and scumming. The solubilized COD will also improve denitrification if the treated sludge is recycled to the anoxic zone. But ozonation will partly inhibit and kill nitrifiers and might therefore lead to a decrease of the effective solid retention time of the nitrifier, which reduces the safety of the nitrification. This paper discusses the effect of ozonation on sludge reduction, the operation stability of nitrification, improvement of denitrification and gives also an energy and cost evaluation. (author)

  14. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... 2016 Articles from Diabetes Forecast® magazine: wcie-meal-planning, In this section Food Planning Meals Diabetes Meal ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  16. Food guide plate

    Science.gov (United States)

    ... chips or cookies. VEGETABLES: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Vegetables can be raw, fresh, ... as a snack. FRUITS: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Fruits can be fresh, canned, ...

  17. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  18. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  19. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets you still choose the foods you want, but changes the portion sizes so you are getting larger ...

  1. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Sleeve Custom jerseys for your Tour de Cure team benefits the cause. Ask the Experts: Learn to ...

  2. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  3. Electrodialytic removal of cadmium from wastewater sludge

    DEFF Research Database (Denmark)

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

    2004-01-01

    This paper presents for the first time laboratory results demonstrating electrodialytic removal of Cd from wastewater sludge, which is a method originally developed for soil remediation. During the remediation a stirred suspension of wastewater sludge was exposed to an electric dc field. The liqu...

  4. Filterability and Sludge Concentration in Membrane Bioreactors

    NARCIS (Netherlands)

    Lousada-Ferreira, M.

    2011-01-01

    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 th

  5. Bioflocculation of mesophilic and thermophilic activated sludge

    NARCIS (Netherlands)

    Vogelaar, J.C.T.; Keizer, de A.; Spijker, S.; Lettinga, G.

    2005-01-01

    Thermophilic activated sludge treatment is often hampered by a turbid effluent. Reasons for this phenomenon are so far unknown. Here, the hypothesis of the temperature dependency of the hydrophobic interaction as a possible cause for diminished thermophilic activated sludge bioflocculation was teste

  6. Heavy metals extraction from anaerobically digested sludge

    NARCIS (Netherlands)

    Marchioretto, M.M.; Bruning, H.; Loan, N.T.P.; Rulkens, W.H.

    2002-01-01

    This paper reports on the chemical extraction efficiency in the removal of heavy metals from sludge from an activated-sludge system, which receives as influent both industrial and municipal wastewater. Utilizing a series of chemical extractants in a sequential order comprised the first phase of the

  7. Heavy metals extraction from anaerobically digested sludge

    NARCIS (Netherlands)

    Marchioretto, M.M.; Bruning, H.; Loan, N.T.P.; Rulkens, W.H.

    2002-01-01

    This paper reports on the chemical extraction efficiency in the removal of heavy metals from sludge from an activated-sludge system, which receives as influent both industrial and municipal wastewater. Utilizing a series of chemical extractants in a sequential order comprised the first phase of the

  8. Carbon monoxide conversion by anaerobic bioreactor sludges

    NARCIS (Netherlands)

    Sipma, J.; Stams, A.J.M.; Lens, P.N.L.; Lettinga, G.

    2003-01-01

    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55degreesC
    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and

  9. Proper use of sludge-control additives in residential heating oil systems

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

    Discussed are various aspects of heating oil `sludge`: How it forms, typical problems it causes, how sludge-control additives work, what should be expected of them, and what happens in a contaminated system when such additives are used. Test results from laboratory and field experiments demonstrate that performance of commercially available additives varies greatly. The concept of `end-of-the-line` treatment is described and compared with bulk fuel treatment. A procedure is described whereby a retailer can test additives himself, and thus determine just what those additives will or will not do for his business. Finally, the economics of an effective treatment program are outlined.

  10. Create Your Plate

    Medline Plus

    Full Text Available ... Reset Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective for both managing diabetes and losing ... en.html Have Type 2 Diabetes? Our free program will help you live well. More from diabetes. ...

  11. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  12. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  13. Evaluation of activated sludge for biodegradation of propylene glycol as an aircraft deicing fluid.

    Science.gov (United States)

    Delorit, Justin D; Racz, LeeAnn

    2014-04-01

    Aircraft deicing fluid used at airport facilities is often collected for treatment or disposal in order to prevent serious ecological threats to nearby surface waters. This study investigated lab scale degradation of propylene glycol, the active ingredient in a common aircraft deicing fluid, by way of a laboratory-scale sequencing batch reactor containing municipal waste water treatment facility activated sludge performing simultaneous organic carbon oxidation and nitrification. The ability of activated sludge to remove propylene glycol was evaluated by studying the biodegradation and sorption characteristics of propylene glycol in an activated sludge medium. The results indicate sorption may play a role in the fate of propylene glycol in AS, and the heterotrophic bacteria readily degrade this compound. Therefore, a field deployable bioreactor may be appropriate for use in flight line applications.

  14. Enzyme disintegration with spatial resolution reveals different distributions of sludge extracellular polymer substances

    National Research Council Canada - National Science Library

    Lü, Fan; Wang, Jingwen; Shao, Liming; He, Pinjing

    2016-01-01

    To understand the intrinsic role of hydrolytic enzymes in sludge treatment, particularly their effect on the digestibility and dewaterability of sludge, activated sludge flocs were disintegrated using...

  15. Vehicle License Plate Character Segmentation

    Institute of Scientific and Technical Information of China (English)

    Mei-Sen Pan; Jun-Biao Yan; Zheng-Hong Xiao

    2008-01-01

    Vehicle license plate (VLP) character segmentation is an important part of the vehicle license plate recognition system (VLPRS). This paper proposes a least square method (LSM) to treat horizontal tilt and vertical tilt in VLP images. Auxiliary lines are added into the image (or the tilt-corrected image) to make the separated parts of each Chinese character to be an interconnected region. The noise regions will be eliminated after two fusing images are merged according to the minimum principle of gray values.Then, the characters are segmented by projection method (PM) and the final character images are obtained. The experimental results show that this method features fast processing and good performance in segmentation.

  16. Mesophilic leaching of copper sulphide sludge

    Directory of Open Access Journals (Sweden)

    VLADIMIR B. CVETKOVSKI

    2009-02-01

    Full Text Available Copper was precipitated using a sodium sulphide solution as the precipitation agent from an acid solution containing 17 g/l copper and 350 g/l sulphuric acid. The particle size of nearly 1 µm in the sulphide sludge sample was detected by optical microscopy. Based on chemical and X-ray diffraction analyses, covellite was detected as the major sulphide mineral. The batch bioleach amenability test was performed at 32 °C on the Tk31 mine mesophilic mixed culture using a residence time of 28 days. The dissolution of copper sulphide by direct catalytic leaching of the sulphides with bacteria attached to the particles was found to be worthy, although a small quantity of ferrous ions had to be added to raise the activity of the bacteria and the redox potential of the culture medium. Throughout the 22-day period of the bioleach test, copper recovery based on residue analysis indicated a copper extraction of 95 %, with copper concentration in the bioleach solution of 15 g/l. The slope of the straight line tangential to the exponential part of the extraction curve gave a copper solubilisation rate of 1.1 g/l per day. This suggests that a copper extraction of 95 % for the period of bioleach test of 13.6 days may be attained in a three-stage bioreactor system.

  17. INVESTIGATION OF INTERMITTENT CHLORINATION SYSTEM IN BIOLOGICAL EXCESS SLUDGE REDUCTION BY SEQUENCING BATCH REACTORS

    Directory of Open Access Journals (Sweden)

    A. Takdastan ، N. Mehrdadi ، A. A. Azimi ، A. Torabian ، G. Nabi Bidhendi

    2009-01-01

    Full Text Available The excessive biological sludge production is one of the disadvantages of aerobic wastewater treatment processes such as sequencing batch reactors. To solve the problem of excess sludge production, oxidizing some of the sludge by chlorine, thus reducing the biomass coefficient as well as the sewage sludge disposal may be a suitable idea. In this study, two sequencing batch reactors, each with 20 L volume and controlled by on-line system were used. After providing the steady state conditions in the reactors, sampling and testing of parameters were done during 8 months. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd were 0.58 mg biomass/mg COD and 0.058/day, respectively. At the next stage, different concentrations of chlorine were used in the reactors intermittently. Results showed that 15 mg chlorine/gMLSS in the reactor was able to reduce the yield coefficient from 0.58 to 0.3 mg biomass/mg COD. In other words, the biological excess sludge was reduced about 48%. But the soluble chemical oxygen demand increased slightly in the effluent and the removal percentage decreased from 95% in the blank reactor to 55% in the test reactor.

  18. Sludge settleability detection using automated SV30 measurement and its application to a field WWTP.

    Science.gov (United States)

    Kim, Y J; Choi, S J; Bae, H; Kim, C W

    2011-01-01

    The need for automation & measurement technologies to detect the process state has been a driving force in the development of various measurements at wastewater treatment plants. While the number of applications of automation & measurement technologies to the field is increasing, there have only been a few cases where they have been applied to the area of sludge settling. This is because it is not easy to develop an automated operation support system for the detection of sludge settleability due to its site-specific characteristics. To automate the human operator's daily test and diagnosis works on sludge settling, an on-line SV30 measurement was developed and an automated detection algorithm on settleability was developed that imitated heuristics to detect settleability faults. The automated SV30 measurement is based on automatic pumping with a predefined schedule, the image capture of the settling test with a digital camera, and an analysis of the images to detect the settled sludge height. A sludge settleability detection method was developed and its applicability was investigated by field application.

  19. Control of Microthrix parvicella and sludge bulking by ozone in a full-scale WWTP.

    Science.gov (United States)

    Levén, Lotta; Wijnbladh, Erik; Tuvesson, Malin; Kragelund, Caroline; Hallin, Sara

    2016-01-01

    Bulking and rising sludge are common problems in wastewater treatment plants (WWTPs) and are primarily caused by increased growth of filamentous bacteria such as Microthrix parvicella. It has a negative impact on sludge settling properties in activated sludge (AS) process, in addition to being responsible for foam formation. Different methods can be used to control sludge bulking. The aim of this study was to evaluate the dosage of on-site generated ozone in the recycled AS flow in a full-scale WWTP having problems caused by M. parvicella. The evaluation of the experiment was assessed by process data, microscopic analysis and microbial screening on the experimental and control line before, during and after the period of ozone dosage. The ozone treatment resulted in decreased abundance of M. parvicella and improved the settling properties, without impairing the overall process performance. Both chemical oxygen demand (COD)- and N-removal were unaffected and the dominant populations involved in nitrification, as analysed by fluorescent in situ hybridization, remained during the experimental period. When the ozone treatment was terminated, the problems with sludge bulking reappeared, indicating the importance of continuous evaluation of the process.

  20. Revised sampling campaigns to provide sludge for treatment process testing

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, C.A.

    1999-02-18

    The purpose of this document is to review the impact to the sludge sampling campaigns planned for FY 1999 given the recent decision to delete any further sludge sampling in the K West Basin. Requirements for Sludge sample material for Sludge treatment process testing are reviewed. Options are discussed for obtaining the volume sample material required and an optimized plan for obtaining this sludge is summarized.

  1. Membrane fouling in a submerged membrane bioreactor with focus on surface properties and interactions of cake sludge and bulk sludge.

    Science.gov (United States)

    Yu, Haiying; Lin, Hongjun; Zhang, Meijia; Hong, Huachang; He, Yiming; Wang, Fangyuan; Zhao, Leihong

    2014-10-01

    In this study, the fouling behaviors and surface properties of cake sludge and bulk sludge in a submerged membrane bioreactor (MBR) were investigated and compared. It was found that the specific filtration resistance (SFR) of cake sludge was about 5 times higher than that of bulk sludge. Two types of sludge possessed similar extracellular polymeric substances (EPS) content, particle size distribution (PSD) and zeta potential. However, their surface properties in terms of surface tensions were significantly different. Further analysis showed that cake sludge was more hydrophilic and had worse aggregation ability. Moreover, cake sludge surface possessed more hydrocarbon, less oxygen and nitrogen moieties than bulk sludge surface. It was suggested that, rather than EPS and PSD differences, the differences in the surface composition were the main cause of the great differences in SFR and adhesion ability between cake sludge and bulk sludge.

  2. Sustainable sludge management in developing countries

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    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

    2003-07-01

    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. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    Science.gov (United States)

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production.

  5. Fast start-up of expanded granular sludge bed (EGSB) reactor using stored Anammox sludge.

    Science.gov (United States)

    Wenjie, Zhang; Yuanyuan, Zhang; Liang, Li; Xuehong, Zhang; Yue, Jin

    2014-01-01

    Stored Anammox sludge (SAS) was used in an expanded granular sludge bed (EGSB) reactor treating synthetic wastewater with the aim of evaluating its possible use as seed sludge. The SAS had been kept in a refrigerator (4 °C) without any feed. After 2 years, only 1-2% Anammox bacteria could survive in the SAS. However, it soon prevailed in the EGSB reactor after loading. Accordingly, the start-up of the EGSB reactor was successfully completed in 34 days. The biomass turned to round reddish granular sludge from irregular brown floc at the end of this study. The results indicate that SAS could serve well as seed sludge. The required time for start-up of the Anammox reactor using SAS was thus demonstrated to be shorter than that of uncultivated sludge under experimental conditions.

  6. Environmental Assessment of Sewage Sludge Management – Focusing on Sludge Treatment Reed Bed Systems

    DEFF Research Database (Denmark)

    Larsen, Julie Dam

    . Fourteen environmental impact categories were included in the LCA, and the environmental loadings and saving provided by the sludge treatment technologies normalised to represent the treatment of 1000 kg wet weight of sludge. The life cycle inventory and the choices underlying the life cycle impact...... gasses CH4 and N2O were larger for mechanical dewatered sludge, the net environmental loadings provided to the impact category Climate Change by this technology (S-CEN) and the STRB system technology (S-STRB and S-SPA) ended up being equally sized (9.010-4 PE), despite of higher biological activity......; however, in the late 1980s, sludge treatment reed bed (STRB) systems were intro-duced in Denmark and in 2016, more than 100 STRB systems were operating in the country. Sludge treatment in STRB systems is often considered more environmentally friendly compared to mechanical sludge treatment technologies...

  7. Metal partitioning and toxicity in sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Carlson-Ekvall, C.E.A.; Morrison, G.M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Sanitary Engineering

    1995-12-31

    Over 20 years of research has failed to provide an unequivocal correlation between chemically extracted metals in sewage sludge applied to agricultural soil and either metal toxicity to soil organisms or crop uptake. Partitioning of metals between phases and species can provide a better estimation of mobility and potential bioavailability. Partition coefficients, K{sub D} for Cd, Cu, Pb and Zn in a sludge/water solution were determined considering the sludge/water solution as a three-phase system (particulate, colloidal and electrochemically available) over a range of pH values, ionic strengths, contact times and sludge/water ratios and compared with the KD values for sludge/water solution as a two-phase system (aqueous phase and particulate phase). Partitioning results were interpreted in terms of metal mobility from sludge to colloids and in terms of potential bioavailability from colloids to electrochemically available. The results show that both mobility and potential bioavailability are high for Zn, while Cu partitions into the mobile colloidal phase which is relatively non-bioavailable. Lead is almost completely bound to the solid phase, and is neither mobile nor bioavailable. A comparison between K, values and toxicity shows that Zn in sludge is more toxic than can be accounted for in the aqueous phase, which can be due to synergistic effects between sludge organics and Zn. Copper demonstrates clear synergism which can be attributed to the formation of lipid-soluble Cu complexes with known sludge components such as LAS, caffeine, myristic acid and nonylphenol.

  8. [Characterisation of excess sludge reduction in an anoxic + oxic-settling-anaerobic activated sludge process].

    Science.gov (United States)

    Gao, Xu; Lu, Yan-Hua; Guo, Jin-Song

    2009-05-15

    An energy balance analysis method with auto calorimeter being adopted was introduced to determine calorific values of sludge samples in influent and effluent of uncoupling tank in an anoxic (A) + oxic-settling-anaerobic (OSA) process and a reference system. The affiliation of sludge amount change and its energy content were studied, as well as potential of excess sludge reduction was evaluated through modifying performance of uncoupling tank. The characteristi s and causes of sludge reduction in OSA system were deduced according to energy and matter balance analysis. Results show that when the hydraulic retention time (HRT) of uncoupling tank are 5.56 h, 7.14 h and 9 h, the excess sludge reduction of whole A + OS Asystem are 1.236 g/d, 0.771 g/d and 0.599 g/d respectively. Energy content of sludge flows into and out of the uncoupling tank changes, the specific calorific value of sludge in effluent is inclined to be higher than that in influent with the HRT of the tank increasing: there isn't any significant difference of sludge calorific values between influent and effluent at 5.56 h, while the differences are in 99-113 J/g at 7.14 h, and 191-329 J/g at 9 h. Sludge in uncoupling tank would decay and longer HRT will result in more attenuation. It could be concluded that excess sludge reduction of A + OSA system is caused by both of sludge decay in uncoupling tank and sludge proliferation in AO reaction zone.

  9. Improvement of anaerobic digestion of sludge

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    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)

  10. Disinfection of sewage sludge with gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Melmed, L.N.; Comninos, D.K.

    1979-10-01

    Disinfection of sewage sludge by ionizing radiation, thermoradiation, and radiation combined with oxygenation was investigated in experimentation in Johannesburg, South Africa. Inactivation of Ascaris lumbricoides ova was used as the criterion of disinfection. Experimentation and methodology are explained. Complete inactivation could be obtained when 0.5 kGy radiation was applied at 50..cap alpha..C to a sludge containing 3% solids and when 0.4 kGy radiation was applied at 55..cap alpha..C to a sludge with 20% solids. (1 drawing, 5 graphs, 4 photos, 4 tables)

  11. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...

  12. Modeling sludge accumulation rates in lined pit latrines in slum ...

    African Journals Online (AJOL)

    Yvonne

    have a performance measure which captures the essential features .... designs, user behaviour, pit dimensions, location and .... Mikhael G, Robbins, DM, Ramsay JE, Mbéguéré M (2014). ... Geneva Switzerland: World Health Organisation.

  13. Sewage sludge disintegration by high-pressure homogenization: A sludge disintegration model

    Institute of Scientific and Technical Information of China (English)

    Yuxuan Zhang; Panyue Zhang; Boqiang Ma; Hao Wu; Sheng Zhang; Xin Xu

    2012-01-01

    High-pressure homogenization (HPH) technology was applied as a pretreatment to disintegrate sewage sludge.The effects of homogenization pressure,homogenization cycle number,and total solid content on sludge disintegration were investigated.The sludge disintegration degree (DDCOD),protein concentration,and polysaccharide concentration increased with the increase of homogenization pressure and homogenization cycle number,and decreased with the increase of sludge total solid (TS) content.The maximum DDCOD of 43.94% was achieved at 80 MPa with four homogenization cycles for a 9.58 g/L TS sludge sample.A HPH sludge disintegration model of DDcoo=kNaPb was established by multivariable linear regression to quantify the effects of homogenization parameters.The homogenization cycle exponent a and homogenization pressure exponent b were 0.4763 and 0.7324 respectively,showing that the effect of homogenization pressure (P) was more significant than that of homogenization cycle number (N).The value of the rate constant k decreased with the increase of sludge total solid content.The specific energy consumption increased with the increment of sludge disintegration efficiency.Lower specific energy consumption was required for higher total solid content sludge.

  14. Performance of Anammox granular sludge bed reactor started up with nitrifying granular sludge

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ping; LIN Feng-mei; HU Bao-lan; CHEN Jian-song

    2004-01-01

    The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully withnitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anammoxgranular sludge with good settling property and high conversion activity. The Anammox reactor worked well with theshortest HRT of 2.43 h. Under the condition that HRT was 6.39 h and influent concentration of ammonia and nitritewas 10 mmol/L, the removal of ammonia and nitrite was 97.17% and 100.00%, respectively. Corresponding

  15. 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.

    2009-07-01

    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)

  16. Palygorskite changes heavy metal bioavailability and microbial functional diversity in sewage sludge composting.

    Science.gov (United States)

    Liu, Siying; Liu, Jia; Zhao, Juanjuan; Xia, Dongsheng; Pan, Fei; Liu, Ci; Kyzas, George Z; Fu, Jie

    2015-01-01

    To investigate the effects of palygorskite on chemical forms of heavy metal and microbial functional diversity in the sewage sludge composting, a compost matrix of sewage sludge, wheat straw and varying contents of palygorskite were inoculated with the compound microbial preparation. The chemical speciation analysis by a Community Bureau of Reference-sequential extraction indicated the contribution of palygorskite to reduce the bioavailability of a model metal, Cu, during the composting process. The Biolog EcoPlate(TM) test revealed that the microbial community showed better capability of utilizing complex macro-molecules (such as miscellaneous and polymers) in the presence of palygorskite. Increasing the palygorskite contents from 1% to 5%, the microbial activity showed an increasing tendency. However, continuously increasing the palygorskite resulted in a decline of the microbial metabolism. Therefore, appropriate content of palygorskite is an ideal additive for composting, not only enhancing the microbial activity, but also reducing the metal toxicity.

  17. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  18. Minimisation of excess sludge production in a WWTP by coupling thermal hydrolysis and rapid anaerobic digestion.

    Science.gov (United States)

    Chauzy, J; Graja, S; Gerardin, F; Crétenot, D; Patria, L; Fernandes, P

    2005-01-01

    In many cases, reducing sludge production could be the solution for wastewater treatment plants (WWTP) that here difficulty evacuating the residuals of wastewater treatment. The aim of this study was to test the possibility of minimising the excess sludge production by coupling a thermal hydrolysis stage and an anaerobic digestion with a very short HRT. The tests were carried out on a 2,500 p.e. pilot plant installed on a recycling loop between the clarifier and the actived sludge basin. The line equipped with the full scale pilot plant produced 38% TSS less than the control line during a 10 week period. Moreover, the rapid anaerobic digestion removed, on average, more than 50% of the total COD load with a hydraulic retention time (HRT) of 3 days. Lastly, the dryness of the remaining excess sludge, sanitised by the thermal hydrolysis, was more than 35% with an industrial centrifuge. This combination of thermal hydrolysis and rapid anaerobic digestion equally permits a significant gain of compactness compared to traditional anaerobic digesters.

  19. Numerical modelling of dynamic sludge blanket behaviour in secondary clarifiers.

    Science.gov (United States)

    Armbruster, M; Krebs, P; Rodi, W

    2001-01-01

    New developments in numerical modelling of turbulent and density-affected flow in secondary clarifiers are reported. The sludge blanket is included in the computation domain which allows us to account for sedimentation and resuspension of sludge as well as the growth and diminution of the sludge blanket and at the same time respecting mass conservation. It is shown how strongly the prediction of the sludge-blanket height depends on the approaches to describe the settling behaviour of the sludge and the rheological properties within the sludge blanket. Further, an example of dynamic simulation is presented and discussed. This demonstrates how the sludge blanket behaves during load variation and that instabilities may occur at the interface of sludge blanket and supernatant, potentially resulting in sludge wash-off during transient phases, which is not only during load increase but also during load decrease.

  20. SLUDGE TREATMENT PROJECT PHASE 1 SLUDGE STORAGE OPTIONS ASSESSMENT OF T PLANT VERSUS ALTERNATE STORAGE FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    RUTHERFORD WW; GEUTHER WJ; STRANKMAN MR; CONRAD EA; RHOADARMER DD; BLACK DM; POTTMEYER JA

    2009-04-29

    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

  1. Application of Chitosan Flocculant to Conditioning Sludge

    Institute of Scientific and Technical Information of China (English)

    李步祥; 陈亮; 陈东辉; 张印堂

    2003-01-01

    The dewaterability of activated sludge conditioned by chitosan fiocculant was studied. The effects of chitasan characteristics such as molecular weight,degree of deacetylation, and dose on the dewaterability were investigated. The sludge dewaterability is evaluated in terms of specific resistance to filtration, residual turbidity of supernatant, moisture content of cake, and settling rate. Sludge dehydrating behaviors conditioned with CTS, PAM and PAC fiocculants were compared. The conditioning was also carried out with dual flocculants in two stages. It is found that the sludge conditioned with CTS has better dewaterability than that with PAC. The optimum conditions with chitosan are: dose 0.8~1.2 g per 100 g dry cake, molecular weight 300,000, and degree of deacetylation 70%. The conditioning in two stages with dual flocculants is found to be more effective than that with single flocculant.

  2. Biodiesel production from municipal secondary sludge.

    Science.gov (United States)

    Kumar, Manish; Ghosh, Pooja; Khosla, Khushboo; Thakur, Indu Shekhar

    2016-09-01

    In the present study, feasibility of biodiesel production from freeze dried sewage sludge was studied and its yield was enhanced by optimization of the in situ transesterification conditions (temperature, catalyst and concentration of sludge solids). Optimized conditions (45°C, 5% catalyst and 0.16g/mL sludge solids) resulted in a 20.76±0.04% biodiesel yield. The purity of biodiesel was ascertained by GC-MS, FT-IR and NMR ((1)H and (13)C) spectroscopy. The biodiesel profile obtained revealed the predominance of methyl esters of fatty acids such as oleic, palmitic, myristic, stearic, lauric, palmitoleic and linoleic acids indicating potential use of sludge as a biodiesel feedstock.

  3. Operator assisted optimization of sludge dewatering

    DEFF Research Database (Denmark)

    Grüttner, Henrik

    1991-01-01

    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)...

  4. Thermal behavior of sewage sludge derived fuels

    Directory of Open Access Journals (Sweden)

    Li Xin-Rui

    2008-01-01

    Full Text Available The utility of sewage sludge as a biomass fuel is taken as an approach to deal with global warming. Thermal characterization of this new type of fuel is a premise before it is practically used in real facilities. Four sludge derived fuels were examined by thermal calorimeters (TG-DTA, C80, and TAM at temperature ramp and isothermal conditions. Heat generation at low temperature was found in some sludge species. The corresponding spontaneous ignition was measured in an adiabatic spontaneous ignition tester at 80 °C. The reason of the thermal behaviors of the sludge fuels was discussed. The critical temperature of large scale pile-up was predicted. .

  5. Evaluation of nitrogen availability in irradiated sewage sludge, sludge compost and manure compost

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Guang; Bates, T.E.; Voroney, R.P. [Univ. of Guelph, Ontario (Canada)

    1995-05-01

    A field experiment was conducted during 2 yr to determine plant availability of organic N from organic wastes, and effects of gamma irradiation on organic N availability in sewage sludge. The wastes investigated were: digested, dewatered sewage sludge (DSS), irradiated sewage sludge (DISS), irradiated, composted sewage sludge (DICSS), and composted livestock manure (CLM). The annual application rates were: 10, 20, 30, and 40 Mg solids ha{sup {minus}1}. Fertilizer N was added to the control, to which no waste was applied, as well as to the waste applications to ensure approximately equal amounts of available N (110 kg N ha{sup {minus}1}) for all treatments. Lettuce, petunias, and beans were grown in 1990 and two cuts of lettuce were harvested in 1991. Crop yields and plant N concentrations were measured. Assuming that crop N harvested/available N applied would be approximately equal for the control and the waste treatments, the N from organic fraction of the wastes, which is as available as that in fertilizer, was estimated. With petunia in 1990 and the combination of first and second cut of lettuce in 1991, the percentage ranged from 11.2 to 29.7 in nonirradiated sludge, 10.1 to 14.0 in irradiated sludge, 10.5 to 32.1 in sludge compost and 10.0 to 19.7 in manure compost. Most often, the highest values were obtained with the lowest application rates. Yields of petunia and N concentrations in second cut lettuce in 1991 were lower with irradiated sludge than with nonirradiated sludge suggest that the availability of organic N in digested sludge may have been reduced after irradiation. Irradiation of sludge appears to have released NH{sub 4}{sup +}-N. The availability of organic N, however, appears to have been reduced by irradiation by greater amount than the increase in NH{sub 4}{sup +}-N. 41 refs., 2 figs., 6 tabs.

  6. Biological Sludge Stabilization; Fenton and Ozonation Processes

    Directory of Open Access Journals (Sweden)

    Miranzadeh M.B.1 PhD,

    2015-09-01

    Full Text Available Aims In biological wastewater treatment processes, a large amount of sludge is produced. Stabilization of sludge is essential before disposal because of the risks to human health and environment. Therefore, selecting an appropriate process for stabilization this sludge may efficiently decrease risks. The aim of this study was to examine the compound efficiency of the advanced Fenton and ozonation oxidation processes in stabilization of biological sludge. Instrument & Methods This experimental study was conducted on raw sludge taken from Kashan University of Medical Sciences’ Wastewater Treatment Plant in Iran during 2014. Fenton and ozonation oxidation processes were used for sludge stabilization. H2O2 and Fe2+ concentration, along with their mutual interaction, were measured using repeated measures model. Then the effects of pH and time reaction on reduction efficiency of volatile solids (VS were examined. Findings The maximum removal efficiencies in Fenton process at pH=3 and in ozonation process in pH=7 were obtained 85.1% and 92.9%, respectively. By increasing the reaction time from 30 to 90min, VS reduction efficiency in Fenton and ozonation processes increased and then reduced after 60min. The maximum reduction efficiencies of VS were obtained at 3000mg/l H2O2 concentration, So that the optimum ratio of Fe2+/H2O2 for sludge stabilization was 1000/3000mg/l with the efficiency of 91.5%. Conclusion Ozonation process efficiency in stabilizing biological wastewater sludge is higher than that of Fenton process.

  7. Structure and stability of methanogenic granular sludge.

    OpenAIRE

    Grotenhuis, J.T.C.

    1992-01-01

    Immobilization of anaerobic bacteria was essential for the development of high rate anaerobic systems for the treatment of waste waters. The most widely applied anaerobic reactor type in which solids retention time is uncoupled from the hydraulic retention time is the Upflow Anaerobic Sludge Blanket (UASB) reactor. In this reactor type methanogenic granular sludge is formed by self-immobilization of methanogenic consortia. The aim of the work presented in this thesis was to study microbiologi...

  8. Gallbladder sludge: what is its clinical significance?

    Science.gov (United States)

    Shaffer, E A

    2001-04-01

    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.

  9. Extracellular polymers of ozonized waste activated sludge.

    Science.gov (United States)

    Liu, J C; Lee, C H; Lai, J Y; Wang, K C; Hsu, Y C; Chang, B V

    2001-01-01

    Effect of ozonation on characteristics of waste activated sludge was investigated in the current study. Concentrations of cell-bound extracellular polymers (washed ECPs) did not change much upon ozonation, whereas the sum of cell-bound and soluble extracellular polymers (unwashed ECPs) increased with increasing ozone dose. Washed ECPs in original sludge as divided by molecular weight distribution was 39% 10,000 Da (high MW). It was observed that the low-MW fraction decreased, and the high-MW fraction increased in ozonized sludge. The unwashed ECPs were characterized as 44% in low MW, 30% in medium MW, and 26% in high MW. Both low-MW and medium-MW fractions of unwashed ECPs decreased while high-MW fraction increased in ozonized sludge. The dewaterability of ozonized sludge, assessed by capillary suction time (CST) and specific resistance to filtration (SRF), deteriorated with ozone dose. The optimal dose of cationic polyelectrolyte increased with increasing ozone dose. The production rate and the accumulated amount of methane gas of ozonized sludge were also higher.

  10. [Study on dewatering of activated sludge under applied electric field].

    Science.gov (United States)

    Ji, Xue-Yuan; Wang, Yi-Li; Feng, Jing

    2012-12-01

    For an electro-dewatering process of activated sludge (AS), the effect of pH and conductivity of AS, flocculation conditioning and operation factors of horizontal electric field (voltage magnitude, method of applying electric field and distance between plates) were investigated, and the corresponding optimum electro-dewatering conditions were also obtained. The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value (6.93) and conductivity (1.46 mS x cm(-1)). CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process, whereas a slight increase in the electro-dewatering rate. The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes, while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes. The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate. Moreover, the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g x kg(-1), electric field strength of 600 V x m(-1), distance between the two plates of 40 mm, dehydration time of 60 minutes. Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly.

  11. IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-05

    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.

  12. Reasonable management plan of sludge in sewage disposal plant

    Energy Technology Data Exchange (ETDEWEB)

    Yum, Kyu Jin; Koo, Hyun Jung [Korea Environment Institute, Seoul (Korea)

    1998-12-01

    The compost method, which is widely used as a sewage disposal recycling in Korea, is now basically impossible to recycle sludge to compost by the Ministry of Agriculture and Forestry announcement. Therefore, the disposal of sludge will be much harder with reducing the amount of sludge used as compost. The amount of sludge other than using as compost is very small, so the development of various sludge recycling and use will be needed with regulations. This study was implemented to help the establishment of sewage sludge recycling policy in Korea. 30 refs., 17 figs., 58 tabs.

  13. Blue Willow Story Plates

    Science.gov (United States)

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  14. Create Your Plate

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Create Your Plate Create Your Plate is a ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning ... Planning Meals Diabetes Meal Plans and a Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets ...

  16. Controlling the motion of multiple objects on a Chladni plate

    National Research Council Canada - National Science Library

    Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

    2016-01-01

    The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate...

  17. Application of forward osmosis (FO) under ultrasonication on sludge thickening of waste activated sludge.

    Science.gov (United States)

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

    2015-01-01

    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.

  18. Chemical stability of acid rock drainage treatment sludge and implications for sludge management

    Energy Technology Data Exchange (ETDEWEB)

    Danny M. McDonald; John A. Webb; Jeff Taylor [La Trobe University, Vic. (Australia). Environmental Geoscience

    2006-03-15

    To assess the chemical stability of sludges generated by neutralizing acid rock drainage (ARD) with alkaline reagents, synthetic ARD was treated with hydrated lime (batch and high-density sludge process), limestone, and two proprietary reagents (KB-1 and Bauxsol). The amorphous metal hydroxide sludge produced was leached using deionized water, U.S. EPA methods (toxicity characteristic leaching procedure, synthetic precipitation leaching procedure), and the new strong acid leach test (SALT), which leaches the sludge with a series of sulfuric acid extractant solutions; the pH decreases by {approximately} 1 pH unit with each test, until the final pH is {approximately}2. Sludges precipitated by all reagents had very similar leachabilities except for KB-1 and Bauxsol, which released more aluminum. SALT showed that lowering the pH of the leaching solution mobilized more metals from the sludges. Iron, aluminum, copper, and zinc began to leach at pH 2.5-3, {approximately}4.5, {approximately}5.5, and 6-6.5, respectively. The leachability of ARD treatment sludges is determined by the final pH of the leachate. A higher neutralization potential (e.g., a greater content of unreacted neutralizing agent) makes sludges inherently more chemically stable. Thus, when ARD or any acidic metalliferous wastewater is treated, a choice must be made between efficient reagent use and resistance to acid attack. 26 refs., 5 figs., 2 tabs.

  19. 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.

    2006-01-01

    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 on

  20. Sludge reduction and performance analysis of a modified sludge reduction process.

    Science.gov (United States)

    Zhou, Zhen; Qiao, Weimin; Xing, Can; Wang, Yingjun; Wang, Chunying; Wang, Yifang; Wang, Yiru; Wang, Luochun

    2014-01-01

    A modified sludge process reduction activated sludge (SPRAS) technology was developed by inserting a sludge process reduction (SPR) module, composed of an aeration tank and a settler, before the activated sludge system was proposed in this study. Compared with the anaerobic/anoxic/aerobic (AAO) process, the SPRAS resulted in a remarkable decrease in sludge production by 76.6%; sludge decay owing to lengthy solids retention time (about 121.5 d) could be the major cause. During the 217-day operation, the oxidation-reduction potential (ORP) (from 54 to -198 mV) and pH (from 7.8 to 5.0) at the bottom of the SPR settler gradually decreased, and low ORP and pH were in favor of sludge reduction in the SPRAS system. The insertion of the SPR module improved the removal efficiencies of suspended solids, chemical oxygen demand and ammonium nitrogen, and total nitrogen concentration in the effluent was reduced from 23.89 ± 4.82 to 14.16 ± 3.98 mg/L by 50% influent bypassing the SPR module. These results indicated that the SPRAS process could produce much less excess sludge and guarantee better effluent quality than the AAO process.

  1. [Comparison of PAHs distribution in stabilized sludge by sludge drying bed and reed bed].

    Science.gov (United States)

    Cui, Yu-Bo; Sun, Hong-Jie; Ran, Chun-Qiu; Li, Jin-Feng; Xie, Yao

    2013-03-01

    The difference in the removal efficiencies of polycyclic aromatic hydrocarbons (PAHs) in planted and unplanted sludge drying bed was investigated. Pilot-scale sludge drying bed and reed bed had the same size of 3.0 m x 1.0 m x 1.3 m (L x W x H), and the bed height consisted of a 65 cm media layer and a 65 cm super height. Both beds had a ventilation pipe which was mounted on the drainage pipes. The experiment lasted for three years, and the first two years was the sludge loading period, and the third year was the natural stabilization period. In the first two years, a total thickness of 8.4 m of sludge was loaded and the average sludge loading rate was 41.3 kg x (m2 x a)(-1). After the three-year stabilization, the contents of the sixteen PAHs decreased with time in both the sludge drying bed and the reed bed. The total PAHs contents in the surface, middle and bottom sludge layers in the sludge drying bed were 4.161, 3.543 and 3.118 mg x kg(-1) (DW), corresponding to 26.91%, 37.77% and 45.23% of removal; and the values in the reed bed were 2.722, 1.648 and 1.218 mg x kg(-1) (DW), corresponding to 52.18%, 71.05% and 78.60% of removal. The average PAHs removal in the reed bed was 29.86% higher than that in the sludge drying bed. In the stabilized sludge, the removal of low-molecular-weight PAHs predominated. The results suggested that reed played a positive role in the removal of PAHs.

  2. K Basin sludge treatment process description

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.

    1998-08-28

    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).

  3. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  4. Plate removal following orthognathic surgery.

    Science.gov (United States)

    Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

    2015-11-01

    The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature.

  5. A study of paint sludge deactivation by pyrolysis reactions

    Directory of Open Access Journals (Sweden)

    Muniz L.A.R.

    2003-01-01

    Full Text Available 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 maximum pressure of 30 atm was used. Following the reactor, a flash separator, which was operated at atmospheric pressure, partially condensed and separated liquid and gas products. Pressure and temperature were monitored on-line by a control and data acquisition system, which adjusted the heating power supplied to the pyrolysis reactor. Reactions followed an experimental design with two factors (reaction time and temperature and three levels (10, 50 and 90 minutes; 450, 550 and 650degreesC. The response variables were liquid and solid masses and net heat of combustion. The optimal operational range for the pyrolysis process was obtained for each response variable. A significant reduction in total mass of solid waste was obtained.

  6. Optimization of up-flow anaerobic sludge blanket reactor for ...

    African Journals Online (AJOL)

    Optimization of up-flow anaerobic sludge blanket reactor for treatment of composite fermentation and distillation wastewater. ... treatment, biogas, granulated anaerobic sludge, industrial wastewater. African Journal of Biotechnology, Vol.

  7. 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.

    2001-03-14

    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.

  8. Anisotropic elastic plates

    CERN Document Server

    Hwu, Chyanbin

    2010-01-01

    As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

  9. Plating in Top Agar

    OpenAIRE

    sprotocols

    2014-01-01

    1. Warm plates to room temperature before use. Cold plates causes the top agar to solidify irregularly. DO not warm plates to 37° as the top agar will take forever to solidify. - Prepare top agar as the appropriate liquid medium with 0.7% agar. Keeping 100 mL bottles is convenient. For phages, use λ top agar, which is less rich and yields bigger plaques. - Melt top agar in the microwave completely. Allow the agar to boil after liquification; incompletely melted agar looks liquid, but is...

  10. Descriptive models for single-jet sluicing of sludge waste

    Energy Technology Data Exchange (ETDEWEB)

    Erian, F.F.; Mahoney, L.A.; Terrones, G.

    1997-12-01

    Mobilization of sludge waste stored in underground storage tanks can be achieved safely and reliably by sluicing. In the project discussed in this report, the waste in Hanford single-shell Tank 241-C-106 will be mobilized by sluicing, retrieved by a slurry retrieval pump, and transferred via an 1800-ft slurry pipeline to Tank 241-AY-102. A sluicing strategy must be developed that ensures efficient use of the deployed configuration of the sluicing system: the nozzle(s) and the retrieval pump(s). Given a sluicing system configuration in a particular tank, it is desirable to prescribe the sequential locations at which the sludge will be mobilized and retrieved and the rate at which these mobilization and retrieval processes take place. In addition, it is necessary to know whether the retrieved waste slurry meets the requirements for cross-site slurry transport. Some of the physical phenomena that take place during mobilization and retrieval and certain aspects of the sluicing process are described in this report. First, a mathematical model gives (1) an idealized geometrical representation of where, within the confines of a storage tank containing a certain amount of settled waste, sludge can be removed and mobilized; and (2) a quantitative measure of the amount of sludge that can be removed during a sluicing campaign. A model describing an idealized water jet issuing from a circular nozzle located at a given height above a flat surface is also presented in this report. This dynamic water-jet model provides the basis for improving the geometrical sluicing model presented next. In this model the authors assume that the water jet follows a straight trajectory toward a target point on a flat surface. However, the water jet does not follow a straight line in the actual tank, and using the true trajectory will allow a more accurate estimate of the amount of disturbed material. Also, the authors hope that developing accurate force and pressure fields will lead to a better

  11. Municipal Sewage Sludge Drying Treatment by an Composite Modifier

    OpenAIRE

    Na Wei

    2012-01-01

    A sludge composite modifier (SCM) which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The res...

  12. Vermistabilization of primary sewage sludge.

    Science.gov (United States)

    Hait, Subrata; Tare, Vinod

    2011-02-01

    An integrated composting-vermicomposting process has been developed for utilization of primary sewage sludge (PSS). Matured vermicompost was used as bulking material and a source of active microbial culture during aerobic activated composting (AAC). AAC resulted in sufficient enrichment of bulking material with organic matter after 20 cycles of recycling and mixing with PSS and produced materials acceptable for vermicomposting. Vermicomposting caused significant reduction in pH, volatile solids (VS), specific oxygen uptake rate (SOUR), total organic carbon (TOC), C/N ratio and pathogens and substantial increase in electrical conductivity (EC), total nitrogen (TN) and total phosphorous (TP) as compared to compost. Environmental conditions and stocking density have profound effects on vermicomposting. Temperature of 20°C with high humidity is favorable environmental condition for vermicomposting employing Eisenia fetida. Favorable stocking density range for vermiculture is 0.5-2.0 kg m(-2) (optimum: 0.5 kg m(-2)) and for vermicomposting is 2.0-4.0 kg m(-2) (optimum: 3.0 kg m(-2)), respectively.

  13. Sludge Hygienization Plant with Electron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Kyu; Kim, Yuri; Han, Bumsoo [EB TECH CO., LTD., Daejeon (Korea, Republic of); Yaacob, Nitzan Ben [Bar Idan Ltd., Shimshit (Israel)

    2008-05-15

    The sludge resulting from municipal wastewater treatment can be used as a soil conditioner. However, it contains bacteria and other micro-organisms, and should be disinfected prior to use. Ionizing Radiation has the ability to inactivate the pathogens with a very high degree of reliability. Accelerated electrons interact with matters, thus causing cell death. Digested sludge from municipal wastewater treatment plant has been used directly for agriculture in Israel, however, owing to the infection by pathogenic microorganisms, the sludge must be processed to reduce the number of pathogens, and the radiation is the solution. An industrial scale plant with the capacity to treat 5 m{sup 3} of dewatered sludge per hour (18% solid contents) with 10 kGy has been planned in municipal wastewater treatment facility Bet Shemesh. This plant will be equipped with an electron accelerator (1.5MeV, 20kW) and handling facilities, and is expected to be more economical than other sludge disposal processes, such as incineration, lime stabilization, etc.

  14. Recovery of phosphorus from sewerage treatment sludge

    Energy Technology Data Exchange (ETDEWEB)

    Manuilova, Anastasia

    1999-07-01

    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%.

  15. Innovative strategies for the reduction of sludge production in activated sludge plant: BIOLYSIS O and BIOLYSIS E

    Energy Technology Data Exchange (ETDEWEB)

    Deleris, Stephane; Larose, A.; Geaugey, V.; Lebrunn, Thierry

    2003-07-01

    Management of the excess sludge production resulting from biological wastewater treatment is one of the most important economic and environmental issues for the next decade. New stringent regulations regarding sludge treatment and disposal imposed in several countries as well as social and environmental concerns, have resulted in an increasing interest in processes allowing the reduction of excess sludge production. Following a 5 years research program, Ondeo-Degremont has developed two processes, Biolysis O and Biolysis E, designed to reduce sludge production during biological wastewater treatment. Experiment performed with Biolysis technologies confirmed that high (up to 80%) reduction of excess sludge production can be reached while good treatment performances are maintained, in agreement with regulation standards. Economical data demonstrate the competitiveness of Biolysis processes. Such processes appear to be a valuable alternative to solve the problem of sludge treatment, to protect operators from the evolution of legislation of sludge treatment and from risks inherent to final sludge disposal.

  16. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... but changes the portion sizes so you are getting larger portions of non-starchy vegetables and a ...

  17. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... 4/Box) Taking the guesswork out of portion control has never been easier. It can be a ...

  18. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  19. MyPlate

    Science.gov (United States)

    ... our stage of life, situations, preferences, access to food, culture, traditions, and the personal decisions we make over time. All your food and beverage choices count. MyPlate offers ideas and ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: September ...

  1. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  2. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes Superfoods Non-starchy Vegetables Grains and Starchy Vegetables ...

  3. Create Your Plate

    Medline Plus

    Full Text Available ... Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning ... serving of dairy or both as your meal plan allows. Choose healthy fats in small amounts. For ...

  4. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Diabetes Get Started Safely Get And Stay Fit Types of Activity Weight Loss Assess Your Lifestyle ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  5. Create Your Plate

    Medline Plus

    Full Text Available ... Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... been easier. It can be a challenge to manage portion control wherever you are. Now, our best- ...

  6. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  7. Create Your Plate

    Medline Plus

    Full Text Available ... Carbohydrates Carbohydrate Counting Make Your Carbs Count Glycemic ... to manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  8. Microbial community in anoxic-oxic-settling-anaerobic sludge reduction process revealed by 454 pyrosequencing analysis.

    Science.gov (United States)

    Ning, Xinqiang; Qiao, Wenwen; Zhang, Lei; Gao, Xu

    2014-12-01

    Modification of the anoxic-oxic (AO) process by inserting a sludge holding tank (SHT) into the sludge return line forms an anoxic-oxic-settling-anaerobic (A+OSA) process that can achieve a 48.98% sludge reduction rate. The 454 pyrosequencing method was used to obtain the microbial communities of the AO and A+OSA processes. Results showed that the microbial community structures of the 2 processes were different as a result of the SHT insertion. Bacteria assigned to the phyla Proteobacteria and Bacteroidetes commonly existed and dominated the microbial populations of the 2 processes. However, the relative abundance of these populations shifted in the presence of SHT. The relative abundance of Proteobacteria decreased during the A+OSA process. A specific comparison at the class level showed that Sphingobacteria was enriched in the A+OSA process. The result suggested that the fermentative bacteria Sphingobacteria may have key functions in reducing the sludge from the A+OSA process. Uncultured Nitrosomonadaceae gradually became the dominant ammonia-oxidizing bacteria, and the nitrite-oxidizing bacterium Nitrospira was enriched in the A+OSA process. Both occurrences were favorable for stabilized nitrogen removal. The known denitrifying species in the A+OSA process were similar to those in the AO process; however, their relative abundance also decreased.

  9. Method for technical, economic and environmental assessment of advanced sludge processing routes.

    Science.gov (United States)

    Svanström, Magdalena; Bertanza, Giorgio; Bolzonella, David; Canato, Matteo; Collivignarelli, Carlo; Heimersson, Sara; Laera, Giuseppe; Mininni, Giuseppe; Peters, Greg; Tomei, Maria Concetta

    2014-01-01

    The legislative framework in force in Europe entails restrictive effluent standards for sensitive areas, and quite severe restrictions on the properties of residual sewage sludge, both for landfill disposal and for agricultural use. Several technologies and management strategies have been proposed and applied in wastewater treatment plants to minimise sludge production and contamination. However, their techno-economic and environmental performance has to be carefully evaluated. The ROUTES project, funded within the EU Seventh Framework programme, aims to find new routes for wastewater treatment and sludge management and thereby guide EU members in their future choices. Within this project, the authors have developed and applied a procedure for techno-economic-environmental assessment of new wastewater and sludge processing lines in comparison to reference plants. The reference plants are model conventional plants that experience different types of problems and the new plants are modified plants in which different innovative technologies have been added to solve these problems. The procedure involves a rating of selected technical issues, estimates of operating costs and an assessment of environmental impacts from a life cycle perspective. This paper reports on the procedure and shows examples of results.

  10. Critical review of the influences of nanoparticles on biological wastewater treatment and sludge digestion.

    Science.gov (United States)

    Wang, Dongbo; Chen, Yinguang

    2016-10-01

    Nanoparticles (NPs), with at least one dimension less than 100 nm, are substantially employed in consumer and industrial products due to their specific physical and chemical properties. The wide uses of engineered NPs inevitably cause their release into the environment, especially wastewater treatment plants. Therefore, it is essential to systematically assess their potential impact on biological wastewater treatment and subsequent sewage sludge digestion. This review aims to provide such support. First, this paper reviews the recent advances on the analytical developments and nano-bio interface of NPs in wastewater and sewage sludge treatment. The effects of NPs on biological wastewater treatment and sewage sludge digestion and related mechanisms are discussed in detail. Finally, the key questions that need to be answered in the future are pointed out, which include on-line revelation of the changes of NPs in sewage and sludge environments, in situ assessment of the variations of microorganisms involved in these biological systems after they are exposed to NPs. Differentiation of the contribution of individual toxicity mechanisms to these systems, and the identification of under what conditions the nanoparticle-induced toxicity will be increased or decreased are also considered.

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

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Diaz, Carlos, E-mail: cbd0044@yahoo.com [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)

    2011-08-15

    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.

  12. 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.

    2006-01-01

    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 applica

  13. Utilization of Household Sewage Sludge in Brick making

    Institute of Scientific and Technical Information of China (English)

    SunGuofeng

    2005-01-01

    Household sewage sludge is a kind of solid waste produced in sewage purifying at sewage farm. in procedure of water purifying, which can be used as raw material for producing fired brick. This article compares the chemical composition between household sewage sludge and clay, and explores two kinds of production process for making brick with Household sewage sludge.

  14. Bioconversion of Selenate in Methanogenic Anaerobic Granular Sludge

    NARCIS (Netherlands)

    Astratinei, V.; Hullebusch, van E.D.; Lens, P.N.L.

    2006-01-01

    The capacity of anaerobic granular sludge to remove selenate from contaminated wastewater was investigated. The potential of different types of granular sludge to remove selenate from the liquid phase was compared to that of suspended sludge and contaminated soil and sediment samples. The selenate r

  15. 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.

    2006-01-01

    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

  16. The role of lipids in activated sludge floc formation

    Directory of Open Access Journals (Sweden)

    Anna Liza Kretzschmar

    2015-03-01

    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.

  17. EU policy on sewage sludge utilization and perspectives on new approaches of sludge management.

    Science.gov (United States)

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

    2015-05-01

    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.

  18. Behavior of inorganic elements during sludge ozonation and their effects on sludge solubilization.

    Science.gov (United States)

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

    2011-02-01

    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.

  19. Effect of sludge retention time on sludge characteristics and membrane fouling of membrane bioreactor

    Institute of Scientific and Technical Information of China (English)

    OUYANG Ke; LIU Junxin

    2009-01-01

    Three identical membrane bioreactors (MBRs) were operated over 2 years at different sludge retention times (SRT) of 10, 40 d and no sludge withdrawal (NS), respectively, to elucidate and quantify the effect of SRT on the sludge characteristics and membrane fouling. The hydraulic retention times of these MBRs were controlled at 12 h. With increasing SRT, the sludge concentrations in the MBRs increased, whereas the ratio of volatile suspended solid to the total solid decreased, and the size of sludge granule diminished in the meantime. A higher sludge concentration at long SRT could maintain a better organic removal efficiency, and a longer SRT was propitious to the growth of nitrifiers. The performance of these MBRs for the removal of COD and NH4+-N did not change much with different SRTs. However, the bioactivity decreased as SRT increased. The measurements of specific oxygen uptake rates (SOUR) and fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes testified that SOUR and the proportion of the bacteria-specific probe EUB338 in all DAPI-stainable bacteria decreased with increasing SRT. The concentrations of total organic carbon, protein, polysaccharides and soluble extracellular polymeric substance (EPS) in the mixed liquor supernatant decreased too with increasing SRT. The membrane fouling rate was higher at shorter SRT, and the highest fouling rate appeared at a SRT of 10 d. Both the sludge cake layer and gel layer had contribution to the fouling resistance, but the relative contribution of the gel layer decreased as SRT increased.

  20. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  1. Fractal multifiber microchannel plates

    Science.gov (United States)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

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

    Science.gov (United States)

    Marti, Erica J; Batista, Jacimaria R

    2014-02-01

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

    Directory of Open Access Journals (Sweden)

    Seswoya Roslinda

    2017-01-01

    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.

  4. Vibration and Buckling of Web Plate of the Plate Girder

    OpenAIRE

    高橋, 和雄; 呉, 明強; 中澤, 聡志; 筑紫, 宏之

    1998-01-01

    The vibration and buckling of the web of the plate girder are studied in this paper. The small deflection theory of the thin plate is used. The finite strip method is employed to solve vibration and buckling of the plate girder. Natural frequenies of buckling properties are shown for various plate girder bridges.

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

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard

    2016-01-01

    and dissolved extracellular polymeric substances (EPS). Polyvalent ions improve the floc strangth and improve the separation whereas monovalent ions (e.g. from road salt, sea water intrusion and industry) reduces impair the separation. Further high pH impairs the separation process due to floc disintegration......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...

  6. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... for the extraction of lipases and proteases from activated sludge. The sludge was continuously stirred in the presence of either buffer alone or in the presence of detergent and/or chelating agents. In all cases, a marked reduction in floc size was observed upon continuous stirring. However, no lipase activity...... and negligible protease activity was extracted in the presence of buffer alone, indicating that enzyme extraction was not due to shear force alone. The highest lipase activity was extracted using 0.1% Triton X-100 above which the activity was gradually decreasing. For proteases, the highest activity was obtained...

  7. Determining organic pollutants in automotive industry sludge.

    Science.gov (United States)

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

    2012-12-01

    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.

  8. High-precision drop shape analysis (HPDSA) of quasistatic contact angles on silanized silicon wafers with different surface topographies during inclining-plate measurements: Influence of the surface roughness on the contact line dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heib, F., E-mail: f.heib@mx.uni-saarland.de [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany); Hempelmann, R. [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany); Munief, W.M.; Ingebrandt, S. [Department of Informatics and Microsystem Technology, University of Applied Sciences, Kaiserslautern, 66482 Zweibrücken (Germany); Fug, F.; Possart, W. [Department of Adhesion and Interphases in Polymers, Saarland University, 66123 Saarbrücken (Germany); Groß, K.; Schmitt, M. [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany)

    2015-07-01

    Highlights: • Analysis of the triple line motion on surfaces with nanoscale surface topographies. • Analysis of the triple line motion is performed in sub-pixel resolution. • A special fitting and statistical approach for contact angle analysis is applied. • The analyses result set of contact angle data which is independent of “user-skills”. • Characteristically density distributions in dependence on the surface properties. - Abstract: Contact angles and wetting of solid surfaces are strongly influenced by the physical and chemical properties of the surfaces. These influence quantities are difficult to distinguish from each other if contact angle measurements are performed by measuring only the advancing θ{sub a} and the receding θ{sub r} contact angle. In this regard, time-dependent water contact angles are measured on two hydrophobic modified silicon wafers with different physical surface topographies. The first surface is nearly atomically flat while the second surface is patterned (alternating flat and nanoscale rough patterns) which is synthesized by a photolithography and etching procedure. The different surface topographies are characterized with atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) and Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The resulting set of contact angle data obtained by the high-precision drop shape analysis approach is further analyzed by a Gompertzian fitting procedure and a statistical counting procedure in dependence on the triple line velocity. The Gompertzian fit is used to analyze overall properties of the surface and dependencies between the motion on the front and the back edge of the droplets. The statistical counting procedure results in the calculation of expectation values E(p) and standard deviations σ(p) for the inclination angle φ, contact angle θ, triple line velocity vel and the covered distance of the triple

  9. Rigid-Plastic Post-Buckling Analysis of Columns and Quadratic Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2008-01-01

    The objective of this paper is to show the application of a novel approach to the rigid plastic hinge and yield line theory in post-buckling analysis of slender plates and columns. The upper bound theorem of plasticity theory and the associated flow law of plasticity are used to find...... of the post-buckling behaviour. The rigid plastic theory of plates, referred to as yield line theory, involves large rigid parts of the plate mutually rotating about yielding hinge lines, however in order to accommodate in plane plastic deformations area “collapse” yield lines have been introduced. The hinge...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...

  10. DEVELOPMENT OF HAZARDOUS SLUDGE SIMULANTS FOR ENHANCED CHEMICAL CLEANING TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Eibling, R.

    2010-04-12

    An Enhanced Chemical Cleaning (ECC) process is being developed by Savannah River Remediation (SRR) to aid in Savannah River Site (SRS) High-Level Waste (HLW) tank closure. After bulk waste removal, the ECC process can be used to dissolve and remove much of the remaining sludge from HLW tanks. The ECC process uses dilute oxalic acid (1 wt %) with in-line pH monitoring and control. The resulting oxalate is decomposed through hydroxylation using an Advanced Oxidation Process (AOP). Minimizing the amount of oxalic acid used for dissolution and the subsequent oxidative destruction of oxalic acid will minimize the potential for downstream impacts. Initial efficacy tests by AREVA demonstrated that previous tank heel simulants could be dissolved using dilute oxalic acid. The oxalate could be decomposed by an AOP that utilized ozone and ultraviolet (UV) light, and the resultant metal oxides and hydroxides could be separated out of the process.

  11. High-precision drop shape analysis (HPDSA) of quasistatic contact angles on silanized silicon wafers with different surface topographies during inclining-plate measurements: Influence of the surface roughness on the contact line dynamics

    Science.gov (United States)

    Heib, F.; Hempelmann, R.; Munief, W. M.; Ingebrandt, S.; Fug, F.; Possart, W.; Groß, K.; Schmitt, M.

    2015-07-01

    Contact angles and wetting of solid surfaces are strongly influenced by the physical and chemical properties of the surfaces. These influence quantities are difficult to distinguish from each other if contact angle measurements are performed by measuring only the advancing θa and the receding θr contact angle. In this regard, time-dependent water contact angles are measured on two hydrophobic modified silicon wafers with different physical surface topographies. The first surface is nearly atomically flat while the second surface is patterned (alternating flat and nanoscale rough patterns) which is synthesized by a photolithography and etching procedure. The different surface topographies are characterized with atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) and Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The resulting set of contact angle data obtained by the high-precision drop shape analysis approach is further analyzed by a Gompertzian fitting procedure and a statistical counting procedure in dependence on the triple line velocity. The Gompertzian fit is used to analyze overall properties of the surface and dependencies between the motion on the front and the back edge of the droplets. The statistical counting procedure results in the calculation of expectation values E(p) and standard deviations σ(p) for the inclination angle φ, contact angle θ, triple line velocity vel and the covered distance of the triple line dis relative to the first boundary points XB,10. Therefore, sessile drops during the inclination of the sample surface are video recorded and different specific contact angle events in dependence on the acceleration/deceleration of the triple line motion are analyzed. This procedure results in characteristically density distributions in dependence on the surface properties. The used procedures lead to the possibility to investigate influences on contact

  12. 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...... for the Evaluation of Substances (EUSES). It is shown how the fraction of substance mass, which is leached, from the top soil is a simple function of the ratio between the degradation half lifetime and the adsorption coefficient. This model can be used in probabilistic risk assessment of agricultural soils...

  13. SLUDGE BATCH 6 PHASE II FLOWSHEET SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D.; Best, D.

    2010-03-30

    Two Sludge Receipt and Adjustment Tank (SRAT) runs were used to demonstrate that a fairly wide window of acid stoichiometry was available for processing SB6 Phase II flowsheet simulant (Tank 40 simulant) while still meeting the dual goals of acceptable nitrate destruction and controlled hydrogen generation. Phase II was an intermediate flowsheet study for the projected composition of Tank 40 after transfer of SB6/Tank 51 sludge to the heel of SB5. The composition was based on August 2009 projections. A window of about 50% in total acid was found between acceptable nitrite destruction and excessive hydrogen generation.

  14. 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...... technologies. Incineration is used as the reference process, as it is the only existing well-developed technology, while other techniques like pyrolysis and gasification are relatively new, and only exist at lab-scale or pilot-plant scale....

  15. Net energy production and emissions mitigation of domestic wastewater treatment system: a comparison of different biogas-sludge use alternatives.

    Science.gov (United States)

    Chen, Shaoqing; Chen, Bin

    2013-09-01

    Wastewater treatment systems are increasingly designed for the recovery of valuable chemicals and energy in addition to waste stream disposal. Herein, the life-cycle energy production and emissions mitigation of a typical domestic wastewater treatment system were assessed, in which different combinations of biogas use and sludge processing lines for industrial or household applications were considered. The results suggested that the reuse of biogas and sludge was so important in the system's overall energy balance and environmental performance that it may offset the cost in the plant's installation and operation. Combined heat and power and household utilization were two prior options for net energy production, provided an ideal power conversion efficiency and biogas production. The joint application of household biogas use and sludge nutrient processing achieved both high net energy production and significant environmental remediation across all impact categories, representing the optimal tradeoff for domestic wastewater treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Monitoring and troubleshooting of non-filamentous settling and dewatering problems in an industrial activated sludge treatment plant

    DEFF Research Database (Denmark)

    Kjellerup, B. V.; Keiding, Kristian; Nielsen, Per Halkjær

    2001-01-01

    A large industrial activated sludge wastewater treatment plant had temporary problems with settling and dewatering of the sludge. Microscopical investigations revealed that the poor settling properties were not due to presence of filamentous bacteria, but poor floc properties. In order...... at this industrial plant. The described strategy can be useful in general to find and solve many solid/liquid separation problems in activated sludge wastewater treatment plants....... had started after summer closedown. Possible reasons for the changes in floc properties in the process tanks were found by a) analysing change in wastewater composition by evaluating the different production lines in the industrial plant, b) evaluating the operation of the plant, and c) performing...

  17. [Bacteriological control of various methods of sewage sludge hygienization].

    Science.gov (United States)

    Breer, C

    1983-09-01

    As a result of extensive parallel investigations in a water treatment plant it was found that the fresh sludge pasteurization or prepasteurization with ensuing sludge digestion gives a product which is unobjectionable from an epidemiological hygienic point of view. The result were confirmed by investigations in a second plant. Similarly satisfactory results were obtained with the composting of previously desiccated sludge, with the aerobic-thermophilic fermentation of liquid sludge or with the drying of sewage sludge. An alternative to these thermal processes is the application of gamma rays or accelerated electrons.

  18. PENERAPAN ELEKTROOSMOSIS UNTUK PENGERINGAN SLUDGE DARI PENGOLAHAN LIMBAH CAIR

    Directory of Open Access Journals (Sweden)

    Darmawan Darmawan

    2013-11-01

    Full Text Available APPLICATION OF ELECTROOSMOSIS FOR DEWATERING OF SLUDGE FROM WASTE WATER TREATMENT. Wastewater treatment produces semi-solid residue (sludge that must be handled carefully during dumping and discharge to avoid polluting the environment. A low cost and easy treatment of dewatering is needed. This research aimed to apply electroosmosis technique for dewatering sludge in order to seek for parameters that can efficiently reduce water content of sludge, including range of voltage, type of electrodes, and distance between electrodes; and to determine the effect of electroosmosis processes on changes of chemical characteristics of sludge. The results showed that: (1 electroosmosis dewatering occurred on the sludge taken from waste water treatment of landfill but not on sludge from water purification plant (PDAM, (2 direct current voltage of 30 volts was the optimum voltage, (3 copper rod cathode provided electroosmosis process as good as stainless steel cathode and both were better than the woven stainless steel cathode, (4 the dewatering time to reduce 1200% (w/w water content to about 400% was about 40 hours for sludge of 2500 cm3 in volume (laboratory bench scale, (5 the anode need to reinserted gradually approaching the cathode due to current lost when the water content at the anode point reached 400% and sludge at the point shrink, and (6 some chemical elements in the sludge decreased significantly after treatment. Pengolahan limbah cair menghasilkan residu berupa bahan semi padat yang dikenal sebagai sludge. Sludge tersebut juga perlu dikelola penyimpanan dan pembuangannya agar tidak mencemari lingkungan. Salah satu pengelolaan sludge yang perlu dilakukan adalah pengeringan (dewatering. Salahsatu teknik dewatering yang mungkin diterapkan ialah teknik elektroosmosis, yaitu teknik yang memanfaatkan adanya pergerakan air pada media poros di dalam medan istrik searah. Penelitian ini bertujuan untuk mencari parameter sistem dewatering secara

  19. History and prospects of irradiation treatment of sewage sludge

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper presents a survey of irradiation treatment of sewage sludge in the world.Since the first sludge irradiation plant was built in Geiselbullach, West Germany in 1973 which used 60Co as irradiation source, many sludge irradiators were constructed in USA, India, Japan, Canada, Poland and so on, which used 60Co, 137Cs or electron beam as irradiation sources.Some basic researches on irradiation treatment of sewage sludge are, respectively, reviewed, including optimization of irradiation parameters, synergistic effect of radiation with heat, oxygenation, irradiation-composting and potential applications of treated sludge.Some proposals have been suggested for further development of this technology.

  20. Influence of secondary settling tank performance on suspended solids mass balance in activated sludge systems.

    Science.gov (United States)

    Patziger, M; Kainz, H; Hunze, M; Józsa, J

    2012-05-01

    Secondary settling is the final step of the activated sludge-based biological waste water treatment. Secondary settling tanks (SSTs) are therefore an essential unit of producing a clear effluent. A further important function of SSTs is the sufficient thickening to achieve highly concentrated return sludge and biomass within the biological reactor. In addition, the storage of activated sludge is also needed in case of peak flow events (Ekama et al., 1997). Due to the importance of a high SST performance the problem has long been investigated (Larsen, 1977; Krebs, 1991; Takács et al., 1991; Ekama et al., 1997; Freimann, 1999; Patziger et al., 2005; Bürger et al., 2011), however, a lot of questions are still to solve regarding e.g. the geometrical features (inflow, outflow) and operations (return sludge control, scraper mechanism, allowable maximum values of surface overflow rates). In our study we focused on SSTs under dynamic load considering both the overall unsteady behaviour and the features around the peaks, investigating the effect of various sludge return strategies as well as the inlet geometry on SST performance. The main research tool was a FLUENT-based novel mass transport model consisting of two modules, a 2D axisymmetric SST model and a mixed reactor model of the biological reactor (BR). The model was calibrated and verified against detailed measurements of flow and concentration patterns, sludge settling, accompanied with continuous on-line measurement of in- and outflow as well as returned flow rates of total suspended solids (TSS) and water. As to the inlet arrangement a reasonable modification of the geometry could result in the suppression of the large scale flow structures of the sludge-water interface thus providing a significant improvement in the SST performance. Furthermore, a critical value of the overflow rate (q(crit)) was found at which a pronounced large scale circulation pattern develops in the vertical plane, the density current in

  1. Production of biosolid fuels from municipal sewage sludge: Technical and economic optimisation.

    Science.gov (United States)

    Wzorek, Małgorzata; Tańczuk, Mariusz

    2015-08-01

    The article presents the technical and economic analysis of the production of fuels from municipal sewage sludge. The analysis involved the production of two types of fuel compositions: sewage sludge with sawdust (PBT fuel) and sewage sludge with meat and bone meal (PBM fuel). The technology of the production line of these sewage fuels was proposed and analysed. The main objective of the study is to find the optimal production capacity. The optimisation analysis was performed for the adopted technical and economic parameters under Polish conditions. The objective function was set as a maximum of the net present value index and the optimisation procedure was carried out for the fuel production line input capacity from 0.5 to 3 t h(-1), using the search step 0.5 t h(-1). On the basis of technical and economic assumptions, economic efficiency indexes of the investment were determined for the case of optimal line productivity. The results of the optimisation analysis show that under appropriate conditions, such as prices of components and prices of produced fuels, the production of fuels from sewage sludge can be profitable. In the case of PBT fuel, calculated economic indexes show the best profitability for the capacity of a plant over 1.5 t h(-1) output, while production of PBM fuel is beneficial for a plant with the maximum of searched capacities: 3.0 t h(-1). Sensitivity analyses carried out during the investigation show that influence of both technical and economic assessments on the location of maximum of objective function (net present value) is significant.

  2. Fabrication of bricks from paper sludge and palm oil fuel ash

    Directory of Open Access Journals (Sweden)

    Mohammad Ismail

    2010-05-01

    Full Text Available line-height: 115%; font-family: ";Times New Roman";,";serif";; mso-fareast-font-family: SimSun; mso-ansi-language: EN-GB; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">Increasing amount of disposed paper sludge and palm oil fuel ash (POFA from industries has recently attracted concern for an alternative environmentally sustainable application. This paper presentsline-height: 115%; font-family: ";Times New Roman";,";serif";; mso-fareast-font-family: SimSun; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;" lang="EN-US"> results of laboratory work carried out on these by-products in order to evaluate application performance. line-height: 115%; font-family: ";Times New Roman";,";serif";; mso-fareast-font-family: SimSun; mso-ansi-language: EN-GB; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">Brick specimens made with various proportions of cement, paper sludge and POFA were fabricated and studied under laboratory conditions. Curing periods of 7, 28 and 84 days were applied followed by compressive strength test. Leaching and water absorption capacities were also assessed as prime steps towards monitoring durability in service. It was found that paper sludge-POFA brick made with 60% cement, 20% sludge and 20% POFA satisfies the strength requirements of BS 6073 Part 2: 2008 and that the amount of copper as well as lead resulting from leaching are within the acceptable limits of ‘Malaysia Environmental Waste Disposal Act’

  3. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  4. Geometrically nonlinear behavior of piezoelectric laminated plates

    Science.gov (United States)

    Rabinovitch, Oded

    2005-08-01

    The geometrically nonlinear behavior of piezo-laminated plates actuated with isotropic or anisotropic piezoelectric layers is analytically investigated. The analytical model is derived using the variational principle of virtual work along with the lamination and plate theories, the von Karman large displacement and moderate rotation kinematic relations, and the anisotropic piezoelectric constitutive laws. A solution strategy that combines the approach of the method of lines, the advantages of the finite element concept, and the variational formulation is developed. This approach yields a set of nonlinear ordinary differential equations with nonlinear boundary conditions, which are solved using the multiple-shooting method. Convergence and verification of the model are examined through comparison with linear and nonlinear results of other approximation methods. The nonlinear response of two active plate structures is investigated numerically. The first plate is actuated in bending using monolithic piezoceramic layers and the second one is actuated in twist using macro-fiber composites. The results quantitatively reveal the complicated in-plane stress state associated with the piezoelectric actuation and the geometrically nonlinear coupling of the in-plane and out-of-plane responses of the plate. The influence of the nonlinear effects ranges from significant stiffening in certain combinations of electrical loads and boundary conditions to amplifications of the induced deflections in others. The paper closes with a summary and conclusions.

  5. Release and control of hydrogen sulfide during sludge thermal drying

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Huanxin; Dai, Zhixin; Ji, Zhongqiang; Gao, Caixia; Liu, Chongxuan

    2015-04-15

    The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: 1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, 2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and 3) decreasing sludge pH increased the H2S release. Based on the findings from this study, a new system that integrates sludge drying and H2S gas treatment was developed to reduce the amount of H2S released from sludge treatments.

  6. Rheology evolution of sludge through high-solid anaerobic digestion.

    Science.gov (United States)

    Dai, Xiaohu; Gai, Xin; Dong, Bin

    2014-12-01

    The main purpose of this study was to investigate the rheology evolution of sludge through high-solid anaerobic digestion (AD) and its dependency on sludge retention time (SRT) and temperature of AD reactor. The operation performance of high-solid AD reactors were also studied. The results showed that sludge became much more flowable after high-solid AD. It was found that the sludge from reactors with long SRT exhibited low levels of shear stress, viscosity, yield stress, consistency index, and high value of flow behaviour index. While the flowability of sludge from thermophilic AD reactors were better than that of sludge from mesophilic AD reactors though the solid content of the formers were higher than that of the latters, which could be attributed to the fact that the formers had more amount of free and interstitial moisture. It might be feasible to use sludge rheology as an AD process controlling parameter. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Possible Co-fermentation of Water and Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Gόrka Justyna

    2017-01-01

    Full Text Available The article describes problems related to intensification of energy production at a wastewater treatment plant. The authors analyzed anaerobic co-digestion of sludge from both water treatment plant and sewage treatment plant. Water sludge is produced during coagulation, ozonation and backwashing of rapid anthracite filters. Its characteristic and properties depend on a raw water quality, treatment methods as well as types of chemicals used and their doses. According to the Polish Act of 4 December 2012 (Journal of Laws from 2013, item 21 the water sludge should be treated as hazardous waste. An alternative way to dispose water sludge and reduce its volume may be sludge reuse. The authors suggested a research methodology and analyzed the preliminary results, which showed that co-digestion of sewage and water sludge enhanced biogas production. The authors assume that the results of the study will provide a basis for development of methodology for sludge control and disposal.

  8. Characteristics of oily sludge combustion in circulating fluidized beds.

    Science.gov (United States)

    Zhou, Lingsheng; Jiang, Xiumin; Liu, Jianguo

    2009-10-15

    Incineration of oily sludge in circulating fluidized beds may be an effective way for its management in some cases. The objective of the present paper is to investigate combustion characteristics of oily sludge, which would be helpful and useful for the design and simulation of a circulating fluidized bed. Firstly, the pyrolysis and combustion of oily sludge were studied through some thermal analyses, which included the thermogravimetric (TG) analysis and the differential thermal analytical (DTA) analysis. It was found that the combustion of oily sludge might be the combustion of its pyrolysis products. Secondly, an experiment for measuring of main components of the volatile from oily sludge pyrolysis was carried out. Some mathematic correlations about the compositions of volatile from oily sludge devolatilization were achieved from the experimental results. Finally, the combustion characteristics of oily sludge was studied in a lab-scale circulating fluidized bed, which could obtain some information about the location of release and combustion of the volatiles.

  9. Gravity Drainage of Activated Sludge on Reed Beds

    DEFF Research Database (Denmark)

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

    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...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows...... that the compressibility has a high influence on the drainage process especially during the start-up phases where the volumetric load on the sludge bed is critical. The load has to be low in order to ensure that the drainage properties of the bed are not destroyed. The data also shows that transport of activated sludge...

  10. Identification and characterisation of oil sludge degrading bacteria isolated from compost

    Directory of Open Access Journals (Sweden)

    Ubani Onyedikachi

    2016-06-01

    Full Text Available Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR. The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.

  11. Tailoring the Electromagnetic Near Field with Patterned Surfaces: Near-Field Plates

    Science.gov (United States)

    2014-12-10

    near-field plates possible. A linear near-field plate is shown in Fig. 1, which can create a subwavelength line (1D) focus when excited by an...concentric annular slots on a circular grounded dielectric slab. The plate is excited through a coaxial cable and its rim is short circuited. The slots are...standard printed circuit board technology. The plates consist of concentric annular slots on a circular grounded dielectric slab excited through a coaxial

  12. 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.

    2007-03-30

    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.

  13. Bench-scale enhanced sludge washing and gravity settling of Hanford Tank C-106 Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, K.P; Myers, R.L; Rappe, K.G.

    1997-01-01

    This report summarizes the results of a bench-scale sludge pretreatment demonstration of the Hanford baseline flowsheet using liter-quantities of sludge from Hanford Site single-shell tank 241-C-106 (tank C-106). The leached and washed sludge from these tests provided Envelope D material for the contractors supporting Tank Waste Remediation System (TWRS) Privatization. Pretreatment of the sludge included enhanced sludge washing and gravity settling tests and providing scale-up data for both these unit operations. Initial and final solids as well as decanted supernatants from each step of the process were analyzed chemically and radiochemically. The results of this work were compared to those of Lumetta et al. (1996a) who performed a similar experiment with 15 grams of C-106, sludge. A summary of the results are shown in Table S.1. Of the major nonradioactive components, those that were significantly removed with enhanced sludge washing included aluminum (31%), chromium (49%), sodium (57%), and phosphorus (35%). Of the radioactive components, a significant amount of {sup 137}Cs (49%) were removed during the enhanced sludge wash. Only a very small fraction of the remaining radionuclides were removed, including {sup 90}Sr (0.4%) and TRU elements (1.5%). These results are consistent with those of the screening test. All of the supernatants (both individually and as a blend) removed from these washing steps, once vitrified as LLW glasses (at 20 wt% Na{sub 2}O), would be less than NRC Class C in TRU elements and less than NRC Class B in {sup 90}Sr.

  14. Controlling the motion of multiple objects on a Chladni plate

    OpenAIRE

    2016-01-01

    The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistica...

  15. Effects of various pretreatments on biohydrogen production from sewage sludge

    Institute of Scientific and Technical Information of China (English)

    XIAO BenYi; LIU JunXin

    2009-01-01

    The sewage sludge of wastewater treatment plant is a kind of biomass which contains many organics,mainly carbohydrates and proteins. Four pretreatments, acid pretreatment, alkaline pretreatment,thermal pretreatment and ultrasonic pretreatment, were used to enhance biohydrogen production from sewage sludge. The experimental results showed that the four pretreatments could all increase the soluble chemical oxygen demand (SCOD) of sludge and decrease the dry solid (DS) and volatile solid(VS) because the pretreatments could disrupt the floc structure and even the microbial cells of sludge.The results of batch anaerobic fermentation experiments demonstrated that all of the four pretreat-ments could select hydrogen-producing microorganisms from the microflora of sludge and enhance the hydrogen production. The hydrogen yield of the alkaline pretreated sludge at initial pH of 11.5 was the maximal (11.68 mL H2/g VS) and that of the thermal pretreated sludge was the next (8.62 mL H2/g VS).The result showed that the hydrogen yield of pretreated sludge was correlative with its SCOD. The hydrogen yields of acid pretreated sludge and alkaline pretreated sludge were also influenced by their initial pH. No methane could be detected in the anaerobic fermentation of alkaline pretreated sludge and thermal pretreated sludge, which suggested that these pretreatments could fully inhibit the activity of methanogens. The volatile fatty acids (VFA) production in anaerobic fermentation of alkaline pretreated sludge was the maximum and the next is that of thermal pretreated sludge.

  16. Biogas recovery from microwave heated sludge by anaerobic digestion

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Biogas generated from sewage sludge,livestock waste,and food waste by anaerobic digestion is a valuable renewable energy resource.However,conventional anaerobic digestion is not an efficient process.A long hydraulic retention time and low biogas recovery rate hinder the applications of those resources.An effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas production.This article focuses on the effects of microwave heating on sludge anaerobic digestion.Volatile suspended solid(VSS) and chemical organic demand solubilization of heated sludge were investigated.Microwave heating was found to be a rapid and efficient process for releasing organic substrates from sludge.The increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave heating.The effect of the VSS solubilization was primarily dependent on heating temperature.The highest value of VSS dissolving ratio,36.4%,was obtained at 170°C for 30 min.The COD dissolving ratio was about 25% at 170°C.Total organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min,respectively.A biochemical methane potential(BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas production.The total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of digestion.Biogas production was 11.1% to 25.9% higher for excess sludge than for untreated sludge.The VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher,respectively,compared to the untreated sludge.

  17. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  18. Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw

    Science.gov (United States)

    Wang, Laifu; Wang, Yan; Lian, Jingyan

    2017-01-01

    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.

  19. Enhanced sludge properties and distribution study of sludge components in electrically-enhanced membrane bioreactor.

    Science.gov (United States)

    Giwa, Adewale; Ahmed, Iftikhar; Hasan, Shadi Wajih

    2015-08-15

    This study investigated the impact of electric field on the physicochemical and biological characteristics of sludge wasted from an electrically-enhanced membrane bioreactor treating medium-strength raw wastewater. This method offers a chemical-free electrokinetic technique to enhance sludge properties and remove heavy metals. For example, sludge volume index (SVI), time-to-filter (TTF), mean sludge particle diameter (PSD), viscosity, and oxidation-reduction potential (ORP) of 21.7 mL/g, 7 min, 40.2 μm, 3.22 mPa s, and -4.9 mV were reported, respectively. Also, X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses provided mechanisms for heavy metal removal so as to establish relevant pathways for nutrient recovery. Furthermore, variations in dissolved oxygen (DO), conductivity, viscosity, ORP, total suspended solids (MLSS), and volatile suspended solids (MLVSS) were interrelated to evaluate the quality of wasted sludge. A pathway study on the transport and chemical distribution of nutrients and metals in sludge showed great potential for metal removal and nutrient recovery.

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

    Directory of Open Access Journals (Sweden)

    J. Sánchez Rubal

    2012-01-01

    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.

  1. 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.

    2003-07-01

    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)

  2. Improved Performance of Membrane Bioreactor by Sludge Ozonation for Reduction of Excess Sludge Production

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi-feng; HE Sheng-bing; CHEN Jian-meng

    2009-01-01

    To seek for an alternative solution for the treatment and disposal of excess activated sludge, a hybrid system of membrane bioreactor ( MBR) coupled with ozonation process (i.e., ozonation run) was set up to treat the domestic wastewater. A reference run without ozonation was also preformed as a control. The optimal ozone dose of solubilization in the ozonation run was firstly determined through the batch sludge ozonation tests. A 40-day continuous operation of the two parallel systems demonstrated that circulation of ozonized sludge as lysate did not impact the performance of MBR in terms of organic and ammonia removal. On the contrary, an improvement in TN removal (by 7.7%) and sludge reduction (by 54%) was observed in the ozonation-combined MBR, and it was furthermore illustrated by the calculation of the mass balance based on the COD and TN substances. In addition,ozonation did not deteriorate the sludge activities for the ozonation run, indicating that not much inert organic materials built up in the bioreactor. Decreased VSS/SS ratio and lower amount of filamentous bacteria after ozonation treatment on the other hand improved the sludge settleability, as lower and constant Sluge Volume Index (SVI) values were detected in the ozonation run.

  3. Additional paper waste in pulping sludge for biohydrogen production by heat-shocked sludge.

    Science.gov (United States)

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

    2012-01-01

    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).

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

    Science.gov (United States)

    Alkan, U; Topaç, F O; Birden, B; Baskaya, H S

    2007-10-01

    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(-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.

  5. License plate detection algorithm

    Science.gov (United States)

    Broitman, Michael; Klopovsky, Yuri; Silinskis, Normunds

    2013-12-01

    A novel algorithm for vehicle license plates localization is proposed. The algorithm is based on pixel intensity transition gradient analysis. Near to 2500 natural-scene gray-level vehicle images of different backgrounds and ambient illumination was tested. The best set of algorithm's parameters produces detection rate up to 0.94. Taking into account abnormal camera location during our tests and therefore geometrical distortion and troubles from trees this result could be considered as passable. Correlation between source data, such as license Plate dimensions and texture, cameras location and others, and parameters of algorithm were also defined.

  6. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

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

    2014-01-01

    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 con

  7. Potential priority pollutants in sewage sludge

    DEFF Research Database (Denmark)

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

    2008-01-01

    Sewage sludge has been used as fertilizer for agricultural land over a long time. This is part of a sustainable practice utilizing and recycling the macronutrients back to land. During the last decades, questions have been raised concerning the risks related to heavy metals and xenobiotic organic...

  8. Bacteria that purify sludge; Des bacteries epuratrices

    Energy Technology Data Exchange (ETDEWEB)

    Peignen-Seraline, P.; Manem, J. [Cirsee, Lyonnaise des Eaux, 92 - Nanterre (France)

    1997-03-01

    Inherent in water purification processes, the formation of sludges is intensively studied. Recently, original bacteria have been observed by searchers: some of them purify water making ``tassels``, others separate them and some of them even participate in the elimination of the first. This research study is described into details and will probably be used in the future at the industrial scale. (O.M.)

  9. Synchronous municipal sewerage-sludge stabilization

    Institute of Scientific and Technical Information of China (English)

    Godefroid Bukuru; Yang Jian

    2005-01-01

    A study on a pilot plant accomplishing synchronous municipal sewerage-sludge stabilization was conducted at a municipal sewerage treatment plant. Stabilization of sewerage and sludge is achieved in three-step process: anaerobic reactor, roughing filter and a microbial-earthworm-ecofilter. The integrated ecofilter utilizes an artificial ecosystem to degrade and stabilize the sewerage and sludge.When the hydraulic retention time(HRT) of the anaerobic reactor is 6 h, the hydraulic load(HL) of the bio-filter is 16 m3/(m2· d), the HL of the eco-filter is 5 m3/(m2 ·d), the recycle ratio of nitrified liquor is 1.5, the removal efficiency is 83%-89% for CODCr, 94%-96% for BOD5, 96%-98% for SS, and 76%-95% for NH3-N. The whole system realizes the zero emission of sludge, and has the characteristics of saving energy consumption and operational costs.

  10. Phosphorus Recovery from Ashes of Sewage Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cornel, Peter; Schaum, Peter

    2003-07-01

    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)

  11. Parasites in soil/sludge systems

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, J.R.

    1978-03-01

    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.

  12. Synchronous municipal sewerage-sludge stabilization.

    Science.gov (United States)

    Bukuru, Godefroid; Jian, Yang

    2005-01-01

    A study on a pilot plant accomplishing synchronous municipal sewerage-sludge stabilization was conducted at a municipal sewerage treatment plant. Stabilization of sewerage and sludge is achieved in three-step process: anaerobic reactor, roughing filter and a microbial-earthworm-ecofilter. The integrated ecofilter utilizes an artificial ecosystem to degrade and stabilize the sewerage and sludge. When the hydraulic retention time(HRT) of the anaerobic reactor is 6 h, the hydraulic load(HL) of the bio-filter is 16 m3/(m2 x d), the HL of the eco-filter is 5 m3/(m2 x d), the recycle ratio of nitrified liquor is 1.5, the removal efficiency is 83%-89% for COD(Cr), 94%-96% for BOD5, 96%-98% for SS, and 76%-95% for NH3-N. The whole system realizes the zero emission of sludge, and has the characteristics of saving energy consumption and operational costs.

  13. Digested sewage sludge gasification in supercritical water.

    Science.gov (United States)

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

    2013-04-01

    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.

  14. Utilization of sludge in building material

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    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)

  15. Preliminary design review report - sludge offload system

    Energy Technology Data Exchange (ETDEWEB)

    Mcwethy, L.M. Westinghouse Hanford

    1996-06-05

    This report documents the conceptual design review of the sludge offload system for the Spent Nuclear Fuel Project. The design description, drawings, available analysis, and safety analysis were reviewed by a peer group. The design review comments and resolutions are documented.

  16. Structure and stability of methanogenic granular sludge.

    NARCIS (Netherlands)

    Grotenhuis, J.T.C.

    1992-01-01

    Immobilization of anaerobic bacteria was essential for the development of high rate anaerobic systems for the treatment of waste waters. The most widely applied anaerobic reactor type in which solids retention time is uncoupled from the hydraulic retention time is the Upflow Anaerobic Sludge Blanket

  17. Utilization of sludge in building material.

    Science.gov (United States)

    Okuno, N; Ishikawa, Y; Shimizu, A; Yoshida, M

    2004-01-01

    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 amounts of energy. However, if they are identified for a process of sludge disposal, all of them are worth considering for a big city where there 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 1,000 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. The question is which is the better, dewatered cake or incinerated ash, for the Portland cement application. The answer is "it depends on the distance between the sewage plant and the Portland cement plant."

  18. Cavitation for improved sludge conversion into biogas

    NARCIS (Netherlands)

    Stoop, A.H.; Bakker, T.W.; Kramer, H.J.M.

    2015-01-01

    In several studies the beneficial influence of pre-treatment of waste activated sludge with cavitation on the biogas production was demonstrated. It is however, still not fully certain whether this effect should be mainly contributed to an increase in conversion rate of organics into biogas by anaer

  19. Sulphation characteristics of paper sludge ash

    Energy Technology Data Exchange (ETDEWEB)

    Roh, S.A. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of); Kim, S.D. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering

    2007-04-15

    Landfills are no longer a viable solution for the disposal of sludge produced from waste water treatment plants because of the decrease in available space, rising fees and growing environmental concerns. However, thermal utilization of this waste may be an economic and sustainable disposal solution. Co-combustion of low heating value sludge with fossil fuels has a positive effect for sulfur dioxide (SO{sub 2}) emissions due to the low sulphur content of biomass fuels and increased sulphur retention in the ash. The sulphur retention is attributed to the formation of sulphates, such as CaSO{sub 4}, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. The amount of fuel-ash-related sulphur sorption increases during co-combustion. Therefore, sorbents for sulphur reduction may not be required if proper control of the biomass feed is maintained. This paper presented a study in which the sulphation characteristics of calcium-rich paper sludge ash were determined for the use of co-combustion of biomass and coal. The calcium in the paper sludge ash came from the limestone filler used in the manufacturing process to increase the density and whiteness of the paper at 2 paper mills in Korea. A thermobalance reactor along with XRD and SEM-EDX were used for the analysis of sulphated ash to determine the effects of sulphation temperature, particle size and SO{sub 2} concentration on sulphation conversion. The activation energy and pre-exponential factor of sulphation reaction of sludge ash were determined based on the uniform-reaction model. X-ray diffraction analysis revealed that most of the sulphation compounds were CaSO{sub 4}. The sulphation occurred uniformly throughout the ash and the CaSO{sub 4} did not block the outer pore of the sludge ash. The uniform distributions of CaO and other inert minerals in the ash resulted in uniform sulphation with good penetration of SO{sub 2} into pores of the sludge ash without pore blocking during sulphation of CaO. 13 refs., 1 tab., 9 figs.

  20. Wastewater and Sludge Reuse Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Ioannis K. Kalavrouziotis

    2016-08-01

    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

  1. Casimir force between metal plate and dielectric plate

    Institute of Scientific and Technical Information of China (English)

    刘中柱; 邵成刚; 罗俊

    1999-01-01

    The Casimir effect between metal plate and dielectric plate is discussed with 1+1-dimensional potential model without using cut-off method. Calculation shows that the Casimir force between metal plate and dielectric plate is determined not only by the potential V0, the dielectric thickness and the distance α between the metal plate and dielectric plate, but also by the dimension of the vessel. When α is far less than the dimension of the vessel, the Casimir force Fc∝α(-1); conversely Fc∝α-2. This result is significant for Casimir force experiment.

  2. SLUDGE BATCH 5 SIMULANT FLOWSHEET STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D; Michael Stone, M; Bradley Pickenheim, B; David Best, D; David Koopman, D

    2008-10-03

    The Defense Waste Processing Facility (DWPF) will transition from Sludge Batch 4 (SB4) processing to Sludge Batch 5 (SB5) processing in early fiscal year 2009. Tests were conducted using non-radioactive simulants of the expected SB5 composition to determine the impact of varying the acid stoichiometry during the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processes. The work was conducted to meet the Technical Task Request (TTR) HLW/DWPF/TTR-2007-0007, Rev. 1 and followed the guidelines of a Task Technical and Quality Assurance Plan (TT&QAP). The flowsheet studies are performed to evaluate the potential chemical processing issues, hydrogen generation rates, and process slurry rheological properties as a function of acid stoichiometry. Initial SB5 flowsheet studies were conducted to guide decisions during the sludge batch preparation process. These studies were conducted with the estimated SB5 composition at the time of the study. The composition has changed slightly since these studies were completed due to changes in the washing plan to prepare SB5 and the estimated SB4 heel mass. Nine DWPF process simulations were completed in 4-L laboratory-scale equipment using both a batch simulant (Tank 51 simulant after washing is complete) and a blend simulant (Tank 40 simulant after Tank 51 transfer is complete). Each simulant had a set of four SRAT and SME simulations at varying acid stoichiometry levels (115%, 130%, 145% and 160%). One additional run was made using blend simulant at 130% acid that included additions of the Actinide Removal Process (ARP) waste prior to acid addition and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) waste following SRAT dewatering. There are several parameters that are noteworthy concerning SB5 sludge: (1) This is the first batch DWPF will be processing that contains sludge that has had a significant fraction of aluminum removed through aluminum dissolution. (2) The sludge is high in mercury

  3. Plants grown on sewage sludge in South China and its relevance to sludge stabilization and metal removal

    Institute of Scientific and Technical Information of China (English)

    SAMAKE Moussa; WU Qi-Tang; MO Ce-hui; MOREL Jean-Louis

    2003-01-01

    The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application. Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants. The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge. Plants growing on sludge beds were investigated to follow their growth and metal uptake. 30 sludge plants were identified during 1 year's observation. A Zn high-accumulating and high growth rate plant(Alocasia macrorrhiza) was selected and grown on sludge beds in plots. The water, organic matter, heavy metals and nutrients contents, the E. coli number and the cress seed germination index were monitored for the sludge samples collected monthly. The plant growth parameters and its heavy metals contents were also determined. The sewage sludge treated by plants could be stabilized at about 5 months, the E. coli number was significantly decreased and the cress seed germination index attained 100%. Crop on sludge could ameliorate the sludge drying. The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period. Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical and bacterial leaching were discussed.

  4. Solution of non-rectangular plates with macroelement method

    Science.gov (United States)

    Delyavskyy, Mykhaylo; Rosinski, Krystian

    2017-03-01

    New approach to static analysis of thin non-rectangular arbitrarily loaded plates, called the macroelement method, has been developed in this paper. Macroelement is a rectangular plate which entirely contains real plate. The mathematical model of macroelement was built. The equilibrium equations are performed for macroelement and boundary conditions are written on the line corresponding to contour of real plate in the nodes which are zero points of trigonometric functions, included in the macroelement model. The load is applied only to separate nodes on the surface of real plate, whereas the complement of a plate to macroelement is unloaded. Analysis of construction is reduced to solving a system of linear algebraic equations. The method provides better accuracy compared to finite element method and requires less equations. There is trapeze plate clamped at inclined edge and simply supported at opposite one considered in this paper. The other edges of the plate are free. Uniformly distributed load on the surface of real plate is taken into account.

  5. Preparation of biochar from sewage sludge

    Science.gov (United States)

    Nieto, Aurora; María Méndez, Ana; Gascó, Gabriel

    2013-04-01

    Biomass waste materials appropriate for biochar production include crop residues (both field residues and processing residues such as nut shells, fruit pits, bagasse, etc), as well as yard, food and forestry wastes, and animal manures. Biochar can and should be made from biomass waste materials and must not contain unacceptable levels of toxins such as heavy metals which can be found in sewage sludge and industrial or landfill waste. Making biochar from biomass waste materials should create no competition for land with any other land use option—such as food production or leaving the land in its pristine state. Large amounts of agricultural, municipal and forestry biomass are currently burned or left to decompose and release CO2 and methane back into the atmosphere. They also can pollute local ground and surface waters—a large issue for livestock wastes. Using these materials to make biochar not only removes them from a pollution cycle, but biochar can be obtained as a by-product of producing energy from this biomass. Sewage sludge is a by-product from wastewater treatment plants, and contains significant amounts of heavy metals, organic toxins and pathogenic microorganisms, which are considered to be harmful to the environment and all living organisms. Agricultural use, land filling and incineration are commonly used as disposal methods. It was, however, reported that sewage sludge applications in agriculture gives rise to an accumulation of harmful components (heavy metals and organic compounds) in soil. For this reason, pyrolysis can be considered as a promising technique to treat the sewage sludge including the production of fuels. The objective of this work is to study the advantages of the biochar prepared from sewage sludge.

  6. Rheology of sludge-slurry grouts

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, E. W.

    1980-10-01

    A series of rheograms was developed that relates the critical velocity (velocity where flow changes from laminar to turbulent) of a cementitious grout that incorporates a suspended sludge-slurry to the critical velocity of a reference grout made with a simulated waste solution. The sludge that is now in the Gunite waste tanks at the Oak Ridge National Laboratory (ORNL) will be suspended and pumped to the new waste storage tanks in Melton Valley. The sludge will then be blended with a cement mix base to form a grout which will be injected underground by the shale fracturing process. This report describes the materials, equipment, and techniques used in the laboratory studies to suspend sludges and mix sludge-slurry grouts that have flow properties similar to those of current shale fracturing grouts. Bentonite clay is an effective suspender in dilute NaNO/sub 3/ solutions; 15 wt % solids can be suspended with 2.0 wt % bentonite in a 0.1 M NaNO/sub 3/ solution. Other suspending materials were evaluated, but bentonite gave the best results. If a slurry grout becomes too viscous to pump, methods must be available to thin the mixture. A number of thinners, friction reducers, and plasticizers were examined. Q-Broxin, a thinner supplied by Baroid, reduced the velocity of a grout required for turbulent flow in a 5.0-cm (2-in.)-diam tube from 1.76 to 1.20 m/s (5.79 to 3.95 ft/s); FX-32C, a plasticizer supplied by Fox Industries, Inc., reduced the velocity from 1.76 to 0.75 m/s (5.6 to 2.45 ft/s).

  7. Nuclear reactor alignment plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  8. Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge

    Institute of Scientific and Technical Information of China (English)

    DAI Jia-yin; CHEN Ling; ZHAO Jian-fu; MA Na

    2006-01-01

    In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those ofZn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of Hg in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metal by Begonia semperflorens-hybr; Ophiopogon japonicus (L.F.) Ker-Gaw; Loropetalum chindense-var. rubrum; Dendranthema morifolium; Viola tricolor; Antirrhinum majus; Buxus radicans Sieb; Viburnum macrocephalum;Osmanthus fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots of D. morifolium, followed by the leaves orB. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var. rubrum

  9. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  10. Create Your Plate

    Medline Plus

    Full Text Available ... Create Your Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... year of delicious meals to help prevent and manage diabetes. Healthy Recipes: ... to your day with this guide. Ways to Give: Wear Your Cause on Your Sleeve - ...

  11. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  12. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  14. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... unsweetened tea or coffee. Featured Product Precise Portions® Go Healthy Travel Pack (4/Box) Taking the guesswork ... you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in a 4-pack. Whether ... Research & Practice We Are Research Leaders We Support Your Doctor ...

  17. INL HIP Plate Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  18. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  19. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals > Create Your Plate Share: Print Page Text Size: A A A Listen En Español Create ... somewhere in between, you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: ... Cost of Diabetes Advocate Toolkit Call to Congress Research & ...

  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.

    1995-07-01

    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.

    Science.gov (United States)

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

    2013-01-01

    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. Evaluation of bangkok sewage sludge for possible agricultural use.

    Science.gov (United States)

    Pasda, Nuanjun; Panichsakpatana, Supamard; Limtong, Pitayakon; Oliver, Robert; Montange, Denis

    2006-04-01

    Bangkok (Thailand) covers more than 1500 km2 and has 10 million inhabitants. The disposal of wastewater is creating huge problems of pollution. The estimated amount of sewage sludge was estimated to be around 108 tonnes dry matter (DM) per day in 2005. In order to find a lasting way of disposal for this sewage sludge, the suitability of the sludge produced from three waste-water treatment plants for use as fertilizing material was investigated. Monthly samplings and analysis of sewage sludge from each plant showed that the composition of sludge varied according to the area of collection and period of sampling, and there was no link to rainfall cycle. Plant nutrient content was high (i.e. total N from 19 to 38 g kg(-1) DM) whereas organic matter content was low. The concentrations of heavy metals varied between sludge samples, and were sometimes higher than the E.U. or U.S. regulations for sewage sludge use in agriculture. Faecal coliforms were present in the sludge from one of the plants, indicating a possible contamination by night soil. In order to decrease this potentially pathogenic population the sewage sludge should be heated by composting. As the C/N ratio of sewage sludge was low (around 6) some organic by-products with high carbon content could be added as structural material to enhance the composting.

  3. Sensitization of Naturally Aged Aluminum 5083 Armor Plate

    Science.gov (United States)

    2015-07-29

    darker areas indicate lighter elements and vice-versa. - 4 - Figure 4. Z -contrast image (a) and corresponding fine-probe EDS line scan (b...probably β) on the grain boundaries, but was generally not continuous. Figure 6(a) and 6(b) shows the Z -contrast image and FPEDS line scan indicating...rich phase precipitation in the specimen in the bottom half of the plate. (a) Z - contrast image and corresponding fine-probe EDS line scan (b). Images

  4. Flexural Behavior of Posttensioned Flat Plates Depending on Tendon Layout

    Directory of Open Access Journals (Sweden)

    Min Sook Kim

    2016-01-01

    Full Text Available This paper discusses the experimental results on the flexural behavior and deflections of posttensioned concrete flat plates depending on tendon layout. One reinforced concrete flat plate and two posttensioned concrete flat plates were manufactured and tested. One-way posttensioning layout and two-way posttensioning layout were considered in this paper. The load-deflection behavior and modes of crack are presented from the test results. Posttension systems effectively controlled crack and deflection. One-way and two-way posttensioning layouts both showed similar maximum load. However, serviceability improved with two-way posttensioning layout compared to one-way posttensioning layout. Also, the yield-line theory was applied to predict the ultimate load for the posttensioned flat plates. The comparison between the test results and estimation by yield-line analysis generally showed good agreement.

  5. 板式催化剂生产线原料加料系统设计与改进%Design and Improvement for Raw material Feeding System of Plate Catalyst Production Line

    Institute of Scientific and Technical Information of China (English)

    郑承霞; 杨光; 梅辉

    2015-01-01

    A SCR catalyst production line is introduce by a steel mill,artificial form of raw materials is used in mixing ma-chine.The efficiency is low and worker's labor load is heavy.In order to improve the efficiency and lighten the labor load,The au-thor designs a raw material feeding system which exposes some problems in practical application.Improvement should be made to perfect the system.%某钢厂引进SCR脱硝板式催化剂生产线,原料市场采购,原料加入混料机采用人工形式,加料效率低,劳动负荷大,为了提高生产效率,降低工人劳动负荷,作者设计了一套原料加料系统,但实际使用中,出现了一些问题,需要改进。

  6. MyPlate Food Guide

    Science.gov (United States)

    ... Choosing the Right Sport for You Shyness MyPlate Food Guide KidsHealth > For Teens > MyPlate Food Guide Print ... other sugary drinks. Avoid oversized portions. continue Five Food Groups Different food groups meet different nutrition needs. ...

  7. What Are Growth Plate Injuries?

    Science.gov (United States)

    ... plate injuries are:  Falling down  Competitive sports (like football)  Recreational activities. Other reasons for growth plate injuries are:  Child abuse  Injury from extreme cold (for ...

  8. Producing hydrogen from wastewater sludge by Clostridium bifermentans.

    Science.gov (United States)

    Wang, C C; Chang, C W; Chu, C P; Lee, D J; Chang, B-V; Liao, C S

    2003-04-10

    Excess wastewater sludge collected from the recycling stream of an activated sludge process is biomass that contains large quantities of polysaccharides and proteins. However, relevant literature indicates that the bio-conversion of wastewater sludge to hydrogen is limited and therefore not economically feasible. This work examined the anaerobic digestion of wastewater sludge using a clostridium strain isolated from the sludge as inoculum. A much higher hydrogen yield than presented in the literature was obtained. Also, the effects of five pre-treatments-ultrasonication, acidification, sterilization, freezing/thawing and adding methanogenic inhibitor-on the production of hydrogen were examined. Freezing and thawing and sterilization increased the specific hydrogen yield by 1.5-2.5 times to that of untreated sludge, while adding an inhibitor and ultrasonication reduced the hydrogen yield.

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

    DEFF Research Database (Denmark)

    Ren, Jingzheng; Liang, Hanwei; Dong, Liang

    2017-01-01

    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......) to identify the critical barriers that hinder the sustainable development of sludge-to-energy industry in China and to investigate the cause-effect relationships among these barriers. Accordingly, some policy implications for promoting the sustainable development of sludge-to-energy industry in China were......, and the evaluation criterion system for sustainability assessment of sludge-to-energy technologies was determined based on the results of grey DEMATEL analysis. Three alternative technologies for sludge-to-electricity were studied by the proposed MCDM method, and the results show that the proposed grey MCDM method...

  10. Bioleaching of chromium from tannery sludge by indigenous Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Wang, Yuan-Shan; Pan, Zhi-Yan; Lang, Jian-Min; Xu, Jian-Miao; Zheng, Yu-Guo

    2007-08-17

    Chromium in tannery sludge will cause serious environmental problems and is toxic to organisms. The acidophilic sulfur-oxidizing Acidithiobacillus thiooxidans can leach heavy metals form urban and industrial wastes. This study examined the ability of an indigenous sulfur-oxidizing A. thiooxidans to leach chromium from tannery sludge. The results showed that the pH of sludge mixture inoculated with the indigenous A. thiooxidans decreased to around 2.0 after 4 days. After 6 days incubation in shaking flasks at 30 degrees C and 160 rpm, up to 99% of chromium was solubilized from tannery sludge. When treated in a 2-l bubble column bioreactor for 5 days at 30 degrees C and aeration of 0.5 vvm, 99.7% of chromium was leached from tannery sludge. The results demonstrated that chromium in tannery sludge can be efficiently leached by the indigenous A. thiooxidans.

  11. A systematic study of the gaseous emissions from biosolids composting: raw sludge versus anaerobically digested sludge.

    Science.gov (United States)

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

    2013-11-01

    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.

  12. Economic assessment of sludge handling and environmental impact of sludge treatment in a reed bed system.

    Science.gov (United States)

    Nielsen, Steen

    2015-01-01

    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.

  13. Controlling Laminate Plate Elastic Behavior

    OpenAIRE

    Mareš, T.

    2004-01-01

    This paper aims to express the relation of a measure of laminate plate stiffness with respect to the fiber orientation of its plies. The inverse of the scalar product of the lateral displacement of the central plane and lateral loading of the plate is the measure of laminate plate stiffness. In the case of a simply supported rectangular laminate plate this measure of stiffness is maximized, and the optimum orientation of its plies is searched.

  14. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  15. Heavy metal cumulation in crops after the sewage sludge application

    Directory of Open Access Journals (Sweden)

    Gondová Andrea

    1998-12-01

    Full Text Available During 1995 - 1996 the crops samples after the sewage sludge application were collected. The heavy metals cumulation in investigated crops from Bardejov increased in order: Zn > Cu > Pb > Ni > Cr > Cd and Banská Bystrica : Zn > Cu > Cr > Ni > Pb > Cd. Heavy metals contents after the sewage sludge application were increased in comparison with the highest admissible concentration in eatable part of crops. The sewage sludge application were not recommended in soils for the growth of vegetables

  16. Mechanisms for Reduced Excess Sludge Production in the Cannibal Process.

    Science.gov (United States)

    Labelle, Marc-André; Dold, Peter L; Comeau, Yves

    2015-08-01

    Reducing excess sludge production is increasingly attractive as a result of rising costs and constraints with respect to sludge treatment and disposal. A technology in which the mechanisms remain not well understood is the Cannibal process, for which very low sludge yields have been reported. The objective of this work was to use modeling as a means to characterize excess sludge production at a full-scale Cannibal facility by providing a long sludge retention time and removing trash and grit by physical processes. The facility was characterized by using its historical data, from discussion with the staff and by conducting a sampling campaign to prepare a solids inventory and an overall mass balance. At the evaluated sludge retention time of 400 days, the sum of the daily loss of suspended solids to the effluent and of the waste activated sludge solids contributed approximately equally to the sum of solids that are wasted daily as trash and grit from the solids separation module. The overall sludge production was estimated to be 0.14 g total suspended solids produced/g chemical oxygen demand removed. The essential functions of the Cannibal process for the reduction of sludge production appear to be to remove trash and grit from the sludge by physical processes of microscreening and hydrocycloning, respectively, and to provide a long sludge retention time, which allows the slow degradation of the "unbiodegradable" influent particulate organics (XU,Inf) and the endogenous residue (XE). The high energy demand of 1.6 kWh/m³ of treated wastewater at the studied facility limits the niche of the Cannibal process to small- to medium-sized facilities in which sludge disposal costs are high but electricity costs are low.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  18. Evaluation of sewage sludge impact on pine and birch development

    OpenAIRE

    Vaitkutė, Dovilė

    2009-01-01

    Sewage sludge could be used in forestry as enrichment of soil properties. It is also expected that sewage sludge which is rich in phosphorus, nitrogen and organic material can enhance the growth of tree seedlings in poor soils. Our study was performed in Taruskos experimental forest site in Panevezys region. The experimental site amended with industrial sewage sludge ten years ago was afforestated with birch and pine seedlings. The aim of our thesis is to evaluate the influence of sewage ...

  19. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  20. Elastic plate spallation

    Science.gov (United States)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  1. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1997-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisaton of the damage, which...

  2. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisation of the damage, which...

  3. 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.

    Science.gov (United States)

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

    2015-11-01

    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

  4. Enzyme extraction by ultrasound from sludge flocs

    Institute of Scientific and Technical Information of China (English)

    YU Guanghui; HE Pinjing; SHAO Liming; ZHU Yishu

    2009-01-01

    Enzymes play essential roles in the biological processes of sludge treatment. In this article, the ultrasound method to extract enzymes from sludge flocs was presented. Results showed that using ultrasound method at 20 kHz could extract more types of enzymes than that ultrasound at 40 kHz and ethylenediamine tetraacetic acid (EDTA) methods. The optimum parameters of ultrasound extraction at 20 kHz were duration of 10 min and power of 480 W. Under the condition, ultrasound could break the cells and extract both the extracellular and intercellular enzymes. Ultrasound power was apparently more susceptive to enzyme extraction than duration, suggesting that the control of power during ultrasound extraction was more important than that of duration. The Pearson correlation analysis between enzyme activities and cation contents revealed that the different types of enzymes had distinct cation binding characteristics.

  5. Laboratory tests of sludge-control additives

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

    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.

  6. Adsorption of Phthalates on Municipal Activated Sludge

    Directory of Open Access Journals (Sweden)

    Hongbo Wang

    2017-01-01

    Full Text Available Phthalates (PAEs are commonly detected in discharge of municipal wastewater treatment plants. This study investigated the removal of six typical PAEs with activated sludge and the results revealed that concentrations of aqueous PAEs decreased rapidly during the beginning 15 min and reached equilibrium within 2 hours due to the adsorption of activated sludge. The process followed first-order kinetic equation, except for dioctyl phthalate (DOP. The factors influencing the adsorption were also evaluated and it was found that higher initial concentrations of PAEs enhanced the removal but affected little the adsorption equilibrium time. The adsorption of PAEs favored lower operating temperature (the optimum temperature was approximately 25°C in this research, which could be an exothermic process. Additionally, lower aqueous pH could also benefit the adsorption.

  7. Reduction in Ammonium Ions in Sludge Liquor

    Directory of Open Access Journals (Sweden)

    Eglė Šlajūtė

    2013-12-01

    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. Sewage sludge disposal strategies for sustainable development.

    Science.gov (United States)

    Kacprzak, Małgorzata; Neczaj, Ewa; Fijałkowski, Krzysztof; Grobelak, Anna; Grosser, Anna; Worwag, Małgorzata; Rorat, Agnieszka; Brattebo, Helge; Almås, Åsgeir; Singh, Bal Ram

    2017-03-14

    The main objective of the present review is to compare the existing sewage sludge management solutions in terms of their environmental sustainability. The most commonly used strategies, that include treatment and disposal has been favored within the present state-of-art, considering existing legislation (at European and national level), characterization, ecotoxicology, waste management and actual routs used currently in particular European countries. Selected decision making tools, namely End-of-waste criteria and Life Cycle Assessment has been proposed in order to appropriately assess the possible environmental, economic and technical evaluation of different systems. Therefore, some basic criteria for the best suitable option selection has been described, in the circular economy "from waste to resources" sense. The importance of sewage sludge as a valuable source of matter and energy has been appreciated, as well as a potential risk related to the application of those strategies.

  9. 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...... the plant effluent. The focus in this work is the top soil as this layer is important for the fate of a xenobiotic substance due to the high biological activity. A simple model for the top soil is used where the substance is assumed homogeneously distributed as suggested in the European Union System...... for the Evaluation of Substances (EUSES). It is shown how the fraction of substance mass, which is leached, from the top soil is a simple function of the ratio between the degradation half lifetime and the adsorption coefficient. This model can be used in probabilistic risk assessment of agricultural soils...

  10. Cavitation for improved sludge conversion into biogas

    Science.gov (United States)

    Stoop, A. H.; Bakker, T. W.; Kramer, H. J. M.

    2015-12-01

    In several studies the beneficial influence of pre-treatment of waste activated sludge with cavitation on the biogas production was demonstrated. It is however, still not fully certain whether this effect should be mainly contributed to an increase in conversion rate of organics into biogas by anaerobic bacteria, and how much cavitation increases the total biogas yield. An increase in yield is only the case if cavitation can further disrupt otherwise inaccessible cell membrane structures and long chain organic molecules. In this study the influence of hydrodynamic cavitation on sludge that was already digested for 30 days was investigated. The total biogas yield could indeed be increased. The effect of the backpressure behind the venturi tube on the yield could not yet be established.

  11. Enhancement of ultrasonic disintegration of sewage sludge by aeration.

    Science.gov (United States)

    Zhao, He; Zhang, Panyue; Zhang, Guangming; Cheng, Rong

    2016-04-01

    Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge.

  12. Enhanced aerobic sludge granulation with layered double hydroxide

    Directory of Open Access Journals (Sweden)

    Jizhi Zhou

    2014-06-01

    Full Text Available Aerobic granular sludge technology has been developed for the biochemical treatment of wastewater in the present study. A fast cultivation of aerobic granular sludge was realized in Sequencing Batch Reactor (SBR, where Mg-Al layered double hydroxide (LDH was used as a carrier for granules growth. In comparison, the sludge particle size with LDH addition was bigger than those without LDH, with more than 50% of compact granular sludge >1.4 mm in size. This indicatestheLDH improved the growth ofthegranular sludge. The frequency of LDH addition had little effect on the granule growth. Moreover, the formation of granules led to the low sludge volume index (SVI and high mixed liquid suspended solids (MLSS in SBR reactor. With the formation of granular sludge, more than 80% of COD was removed in SBR reactor. The high COD removal efficiency of wastewater was observed regardless of various COD loading strength. The results suggest that the growth of granular sludge with LDH as a carrier enhanced the treatment efficiency. Therefore, our results have provided a promising way to prepare the granular sludge for wastewater treatment.

  13. Effect of proteins, polysaccharides, and particle sizes on sludge dewaterability

    Institute of Scientific and Technical Information of China (English)

    SHAO Liming; HE Peipei; YU Guanghui; HE Pinjing

    2009-01-01

    Four batch experiments of hydrolysis and acidification were carried out to investigate the distributions of proteins (PN) and polysaccharides (PS) in the sludge, the PN/PS ratio, the particle sizes, and their relationship with sludge dewaterability (as determined by capillary suction time, CST). The sludge flocs were stratified through centrifugation- and ultrasound-based method into four layers: (1) slime, (2) loosely bound extracellular polymeric substances (LB-EPS), (3) tightly bound EPS (TB-EPS), and (4) pellet. The results showed that PN was mainly partitioned in the pellet (80.7%) and TB-EPS (9.6%) layers, while PS distributed evenly in the four layers. During hydrolysis and acidification, PN was transferred from the pellet and TB-EPS layers to the slime layer, but PS had no significant transfer trends. The mean particle sizes of the sludge flocs decreased with hydrolysis and acidification. The pH had a more significant influence on the dewaterability of sludge flocs than temperature. Sludge dewaterability during hydrolysis and acidification processes greatly deteriorated from 9.7 s at raw sludge to 340--450 s under alkaline conditions. However, it was just slightly increased under acidic conditions. Further investigation suggested that CST was affected by soluble PN, soluble PN/PS, and particle sizes of sludge flocs, but was affected slightly by total PN, PS, or PN/PS in the whole sludge flocs and other layers (except slime).

  14. Electron beam/biological processing of anaerobic and aerobic sludge

    Science.gov (United States)

    Čuba, V.; Pospíšil, M.; Múčka, V.; Jeníček, P.; Dohányos, M.; Zábranská, J.

    2003-01-01

    Besides common chemical and biological methods, the radiation technology is a promising way of sludge treatment. The paper describes possibilities of combined accelerated electrons/biological processing of both anaerobic and aerobic sludge. Besides one-shot experiments, experimental reactors for the simulation of anaerobic processes have been used. Main effort has been aimed to decrease organic compounds concentration and overall volume of solids, to improve some physico-chemical parameters of sludge, to validate hygienisation effects of the ionising radiation, and in the case of anaerobic sludge, to increase the volume of the produced biogas. Positive effects of the electron beam processing have been observed on all previously named parameters.

  15. Rheology of Savannah River site tank 42 HLW radioactive sludge

    Energy Technology Data Exchange (ETDEWEB)

    Ha, B.C.

    1997-11-05

    Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site, Tank 42 sludge represents on of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility. The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center using a modified Haake Rotovisco viscometer.

  16. Sludge Reduction by Lumbriculus Variegatus in Ahvaz Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Tim Hendrickx

    2012-08-01

    Full Text Available 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 extensivehealth hazards. Application of aquatic worm is an approach to decrease the amount of biological waste sludge produced in wastewater treatment plants. In the present research reduction of the amount of waste sludge from Ahvaz wastewater treatment plant was studied with the aquatic worm Lumbriculus variegatus in a reactor concept. The sludge reduction in the reactor with worm was compared to sludge reduction in a blank reactor (without worm.The effects of changes in dissolved oxygen (DO concentration up to 3 mg/L (run 1 and up to 6 mg/L (run 2 were studied in the worm and blank reactors. No meaningful relationship was found between DO concentration and the rate of total suspended solids reduction. Theaverage sludge reductions were obtained as 33% (run 2 and 32% (run 1 in worm reactor,and 16% (run 1 and 12% (run 2 in the blank reactor. These results showed that the worm reactors may reduce the waste sludge between 2 and 2.75 times higher than in the blankconditions. The obtained results showed that the worm reactor has a high potential for use in large-scale sludge processing.

  17. Experimental Study on Minimization of Sludge Production by Ozonation Process

    Institute of Scientific and Technical Information of China (English)

    何圣兵; 薛罡; 王宝贞; 王琳

    2003-01-01

    Based on the hypothesis of reducing sludge production under cryptic growth conditions, ozone was used as cell lysis agent to treat excess sludge,and then the ozonated supernatant was returned to the aeration tank. The results show that COD and NH+4-N removal efficiencies in ozonation process were 87.96% and 84.42%, respectively. Meanwhile, a low excess sludge yield coefficient of 0. 113 ( g SS/g COD removed) was obtained. Compared with that of the control test, the process configuration decreased the excess sludge production by 51.3%.

  18. Digital image processing and analysis for activated sludge wastewater treatment.

    Science.gov (United States)

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

    2015-01-01

    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.

  19. Properties of wastepaper sludge in geopolymer mortars for masonry applications.

    Science.gov (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi

    2012-12-15

    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.

  20. Treating both wastewater and excess sludge with an innovative process

    Institute of Scientific and Technical Information of China (English)

    HE Sheng-bing; WANG Bao-zhen; WANG Lin; JIANG Yi-feng

    2003-01-01

    The innovative process consists of biological unit for wastewater treatment and ozonation unit for excess sludge treatment. An aerobic membrane bioreactor(MBR) was used to remove organics and nitrogen, and an anaerobic reactor was added to the biological unit for the release of phosphorus contained at aerobic sludge to enhance the removal of phosphorus. For the excess sludge produced in the MBR, which was fed to ozone contact column and reacted with ozone, then the ozonated sludge was returned to the MBR for further biological treatment. Experimental results showed that this process could remove organics, nitrogen and phosphorus efficiently, and the removals for COD, NH3-N, TN and TP were 93.17 %, 97.57 %, 82.77 % and 79.5 %, respectively. Batch test indicated that the specific nitrification rate and specific denitrification Under the test conditions, the sludge concentration in the MBR was kept at 5000-6000 mg/L, and the wasted sludge was ozonated at an ozone dosage of 0.10 kgO3/kgSS. During the experimental period of two months, no excess sludge was wasted, and a zero withdrawal of excess sludge was implemented. Through economic analysis, it was found that an additional ozonation operating cost for treatment of both wastewater and excess sludge was only 0.045 RMB Yuan(USD 0.0054)/m3 wastewater.

  1. Recovery of wastewater sludge components by acid hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Recktenwald, Michael; Karlsson, Ingemar

    2003-07-01

    Municipal waste water sludge is a complex product containing both valuable products and contaminants. The valuable products are phosphorus, organic matter and precipitants. The contaminants include heavy metals and organic micro pollutants. Consumers, farmers and their organisations are restrictive to utilisation of sludge on arable land. Disposal of organic waste will be prohibited in 2005. Thus the sludge treatment process, KREPRO, has been developed. From the waste water sludge, different fractions can be separated and reused such as organic fraction, phosphate, precipitants and carbon source. (author)

  2. Modelling of Activated Sludge Wastewater Treatment

    OpenAIRE

    Kurtanjeka, Ž.; Deverić Meštrović, B.; Ležajić, Z.; Bevetek, A.; Čurlin; M.

    2008-01-01

    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 b...

  3. Fractional Distribution of Lead and Cadmium in Sludge and Soil Amended with Sludge Compost

    Institute of Scientific and Technical Information of China (English)

    E Yong; BIAN Wei; SHAN Dexin; ZHANG Di; FU Chunlei

    2006-01-01

    The modified three-step sequential extraction procedure proposed by the BCR was used to predict Pb and Cd fractional distribution in sewage sludge and tomato soil amended with sludge compost. There was no significant increasing of Pb and Cd contents in the soil with sludge application as compared with that in the reference soil. The Pb contents were much lower for the soil samples than for the National Soil Standards of Environmental Quality, but Cd contents in soil were much more than background mean Cd contents. Pb content in soil fractions was followed with residual Pb > reducible Pb > exchangeable and weak acid soluble Pb > oxidizable Pb. In all soil samples, the partitioning of Cd had the same extractability in the first two steps of the procedure and the residual fraction. Only a small fraction or almost zero extractability was observed at the oxidation step for Pb and Cd.

  4. SLUDGE BATCH 7B QUALIFICATION ACTIVITIES WITH SRS TANK FARM SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J.; Click, D.; Lambert, D.; Reboul, S.

    2011-11-16

    Waste Solidification Engineering (WSE) has requested that characterization and a radioactive demonstration of the next batch of sludge slurry - Sludge Batch 7b (SB7b) - 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 typically simulates the Tank Farm and DWPF processes with a Tank 51 sample (referred to as the qualification sample). With the tight schedule constraints for SB7b and the potential need for caustic addition to allow for an acceptable glass processing window, the qualification for SB7b was approached differently than past batches. For SB7b, SRNL prepared a Tank 51 and a Tank 40 sample for qualification. SRNL did not receive the qualification sample from Tank 51 nor did it simulate all of the Tank Farm washing and decanting operations. Instead, SRNL prepared a Tank 51 SB7b sample from samples of Tank 7 and Tank 51, along with a wash solution to adjust the supernatant composition to the final SB7b Tank 51 Tank Farm projections. SRNL then prepared a sample to represent SB7b in Tank 40 by combining portions of the SRNL-prepared Tank 51 SB7b sample and a Tank 40 Sludge Batch 7a (SB7a) sample. The blended sample was 71% Tank 40 (SB7a) and 29% Tank 7/Tank 51 on an insoluble solids basis. This sample is referred to as the SB7b Qualification Sample. The blend represented the highest projected Tank 40 heel (as of May 25, 2011), and thus, the highest

  5. Sludge characterization: the role of physical consistency

    Energy Technology Data Exchange (ETDEWEB)

    Spinosa, Ludovico; Wichmann, Knut

    2003-07-01

    The physical consistency is an important parameter in sewage sludge characterization as it strongly affects almost all treatment, utilization and disposal operations. In addition, in many european Directives a reference to the physical consistency is reported as a characteristic to be evaluated for fulfilling the regulations requirements. Further, in many analytical methods for sludge different procedures are indicated depending on whether a sample is liquid or not, is solid or not. Three physical behaviours (liquid, paste-like and solid) can be observed with sludges, so the development of analytical procedures to define the boundary limit between liquid and paste-like behaviours (flowability) and that between solid and paste-like ones (solidity) is of growing interest. Several devices can be used for evaluating the flowability and solidity properties, but often they are costly and difficult to be operated in the field. Tests have been carried out to evaluate the possibility to adopt a simple extrusion procedure for flowability measurements, and a Vicat needle for solidity ones. (author)

  6. Microwave oxidation treatment of sewage sludge.

    Science.gov (United States)

    Lo, Kwang V; Srinivasan, Asha; Liao, Ping H; Bailey, Sam

    2015-01-01

    Microwave-oxidation treatment of sewage sludge using various oxidants was studied. Two treatment schemes with a combination of hydrogen peroxide and ozone were examined: hydrogen peroxide and ozone were introduced into the sludge simultaneously, followed by microwave heating. The other involved the ozonation first, and then the resulting solution was subjected to microwave and hydrogen peroxide treatment. The set with ozonation followed by hydrogen peroxide plus microwave heating yielded higher soluble materials than those of the set with hydrogen peroxide plus ozone first and then microwave treatment. No settling was observed for all treatments in the batch operation, except ozone/microwave plus hydrogen peroxide set at 120°C. The pilot-scale continuous-flow 915 MHz microwave study has demonstrated that microwave-oxidation process is feasible for real-time industrial application. It would help in providing key data for the design of a full-scale system for treating sewage sludge and the formulation of operational protocols.

  7. Supercritical water oxidation treatment of textile sludge.

    Science.gov (United States)

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

    2016-10-17

    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.

  8. On the rheological characteristics of sewage sludge

    Directory of Open Access Journals (Sweden)

    Tomáš Vítěz

    2010-01-01

    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.

  9. Plate tectonics conserves angular momentum

    Directory of Open Access Journals (Sweden)

    C. Bowin

    2009-03-01

    Full Text Available A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s−1. Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates. Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth. The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive

  10. Vehicle License Plate Recognition Syst

    Directory of Open Access Journals (Sweden)

    Meenakshi,R. B. Dubey

    2012-12-01

    Full Text Available The vehicle license plate recognition system has greater efficiency for vehicle monitoring in automatic zone access control. This Plate recognition system will avoid special tags, since all vehicles possess a unique registration number plate. A number of techniques have been used for car plate characters recognition. This system uses neural network character recognition and pattern matching of characters as two character recognition techniques. In this approach multilayer feed-forward back-propagation algorithm is used. The performance of the proposed algorithm has been tested on several car plates and provides very satisfactory results.

  11. Using plate mapping to examine portion size and plate composition for large and small divided plates.

    Science.gov (United States)

    Sharp, David E; Sobal, Jeffery; Wansink, Brian

    2014-12-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods - such as meat versus vegetables - differently? To examine this question, we used the new method of plate mapping, where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, which showed that the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are that plate size may influence portion size and change the proportions of foods served.

  12. 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

    2017-06-01

    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.

  13. Transient motion of thick anisotropic plates

    Science.gov (United States)

    Nayfeh, Adnan H.; Taylor, Timothy W.

    1991-01-01

    Analyses are developed for the response of anisotropic plate strips to a transient load. The load is taken in the form of a line load of normal stress on the surface or within the body of the strip. The characteristic free vibrational modes of the strip are derived and used to derive the secular equation for this case in closed form and to isolate the mathematical conditions for symmetric and antisymmetric wave mode propagation in completely separate terms. The applied loads are expanded in terms of these normal modes and the response of the plate is obtained by superposition of the appropriate components. Material systems of higher symmetry are contained implicitly in the analysis.

  14. Temperature field of steel plate cooling process after plate rolling

    Directory of Open Access Journals (Sweden)

    Huijun Feng, Lingen Chen, Fengrui Sun

    2015-01-01

    Full Text Available Based on numerical calculation with Matlab, the study on cooling process after plate rolling is carried out, and the temperature field distribution of the plate varying with the time is obtained. The effects of the plate thickness, final rolling temperature, cooling water temperature, average flow rate of the cooling water, carbon content of the plate and cooling method on the plate surface and central temperatures as well as final cooling temperature are discussed. For the same cooling time, the plate surface and central temperatures as well as their temperature difference increase; with the decrease in rolling temperature and the increase in average flow rate of the cooling water, the plate surface and central temperatures decrease. Compared with the single water cooling process, the temperature difference between the plate centre and surface based on intermittent cooling is lower. In this case, the temperature uniformity of the plate is better, and the corresponding thermal stress is lower. The fitting equation of the final cooling temperature with respect to plate thickness, final rolling temperature, cooling water temperature and average flow rate of the cooling water is obtained.

  15. Sludge como fator de risco para prematuridade

    Directory of Open Access Journals (Sweden)

    Elizabeth Kazuko Watanabe

    2016-10-01

    Full Text Available Introdução: O trabalho de parto prematuro (TPP é um grave problema de saúde pública devido à elevada morbidade e mortalidade neonatal.Como fatores de risco,destacam-se o baixo nível socioeconômico,nutrição inadequada,extremos de idade,estresse físico e psicológico,tabagismo e drogas ilícitas.Intecorrências como incompetência cervival,placenta de inserção baixa,descolamento prematuro de placenta,polidramnio,gemelaridade, rotura prematura de membranas,história prévia de parto prematuro são causas obstétricas e ginecológicas. Dentre as infecções,a corioamnionite é uma das mais importantes.A prevenção e a predição da prematuridade têm sido alvo de pesquisas através de métodos clínicos, bioquímicos e ultrassonográficos. À ultrassonografia(US,a medida do comprimento de colo uterino com transdutor vaginal(TV e a pesquisa do eco glandular endocervical auxiliam na predição do parto prematuro. Outro sinal ultrassonográfico que parece estar associado à infecção e à prematuridade é o sludge,um agregado espesso de partículas no líquido amniótico próximo ao orifício interno do colo uterino.A associação sludge e colo curto(menor que 25mmaumenta o risco de TPP. Objetivo/Metodologia: apresentamos um caso de sludge em gestante com 16 semanas e antecedente de TPP. Relato de caso:TPDA,24anos,secundigesta primípara(natimorto com 29 semanas,realizou USTV devido a colo entreaberto ao toque vaginal e ao passado obstétrico. Ao exame,visualizou-se sludge e colo medindo 3,8cm de comprimento. Foi internada para tratamento com Clindamicina e Cefalexina via oral por 10 dias.Exames de urina I, hemograma e proteína C reativa normais na internação. Alta após 5 dias,com acompanhamento semanal e prescrição de progesterona 200mg via vaginal. Conclusão: o sludge é um sinal preditor de prematuridade.

  16. Real Plates and Dubious Microplates

    Science.gov (United States)

    Kogan, M. G.; Steblov, G. M.

    2008-12-01

    From the onset of plate tectonics, the existence of most of the plates was never put in doubt, although the boundaries of some plates, like Africa, were later revised. There are however, two microplates in northeast Asia, the Amurian and Okhotsk, whose existence and the sense of rotation was revised several times. The rms value of plate-residual GPS velocities is 0.5-0.9 mm/a for sets of stations representing the motion of the following plates: Antarctic, Australian, Eurasian, North American, Nubian, Pacific, and South American. This value can be regarded as an upper bound on deviation of real plates from infinite stiffness. The rms value of plate-residual GPS velocities is 1.2-1.8 mm/a for the Indian, Nazca, and Somalian plates. Higher rms values for India and Nazca are attributed to the noisier data. The higher rms value for Somalia appears to arise from the distributed deformation to the east of the East African Rift; whether this statement is true can only be decided from observations of denser network in the future. From the analysis of plate-residual GPS velocities, the Canadian Arctic and northeastern Siberia belong to the North American plate. The detailed GPS survey on Sakhalin Island shows that the Sea of Okhotsk region also belongs to the North American plate while the region to the west of it belongs to the Eurasian plate. These results provide a constraint on the geometry of the North American plate and put in doubt the existence of smaller plates in northeast Asia.

  17. Flocculation and dewaterability of chemically enhanced primary treatment sludge by bioaugmentation with filamentous fungi.

    Science.gov (United States)

    Murugesan, Kumarasamy; Selvam, Ammaiyappan; Wong, Jonathan W C

    2014-09-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Soudani Leila

    2017-03-01

    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.

  19. An Automatic System of Vehicle Number-Plate Recognition Based on Neural Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents an automatic system of vehicle number-plate recognition based on neural networks. In this system, location of number-plate and recognition of characters in number-plate can be automatically completed. Pixel colors of Number-plate area are classified using neural network, then color features are extracted by analyzing scanning lines of the cross-section of number-plate. It takes full use of number-plate color features to locate number plate. Characters in number-plate can be effectively recognized using the neural networks. Experimental results show that the correct rate of number-plate location is close to 100%, and the time of number-plate location is less than 1 second. Moreover, recognition rate of characters is improved due to the known number-plate type. It is also observed that this system is not sensitive to variations of weather, illumination and vehicle speed. In addition, and also the size of number-plate need not to be known in prior. This system is of crucial significance to apply and spread the automatic system of vehicle number-plate recognition.

  20. Plate Full of Color

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Plate Full of Color teaches the value of eating a variety of colorful and healthy foods.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  1. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  2. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  3. Enhancing faecal sludge management in peri-urban areas of Lusaka through faecal sludge valorisation: challenges and opportunities

    Science.gov (United States)

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

    2017-03-01

    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.

  4. Biostimulatory Effect Of Processed Sewage Sludge In Bioremediation Of Engine Oil Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Kamaluddeen

    2015-08-01

    Full Text Available A study was conducted to evaluate the influence of sewage sludge on biodegradation of engine oil in contaminated soil. Soil samples were collected from a mechanics workshop in Sokoto metropolis. The Soil samples were taken to the laboratory for isolation of engine oil degrading bacteria. About 1 g of soil sample was used to inoculate 9 ml of trypticase soy broth and incubated at 28oC for 24 h. The growth obtained was sub-cultured in mineral salt medium overlaid with crude oil and allowed to stand at 28oC for 72 h. The culture obtained was then maintained on tryticase soy agar plates at 28oC for 48 h. A combination of microscopy and biochemical tests was carried out to identify the colonies. The sewage sludge was obtained from sewage collection point located behind Jibril Aminu Hall of Usmanu Danfodiyo University Sokoto and processed i.e. dried grounded and sterilized. A portion of land obtained in a botanical garden was divided into small portions 30 X 30 cm and the soil was excavated in-situ and sterilized in the laboratory. A polythene bag was subsequently used to demarcate between the sterilized soil and the garden soil. The sterilized soil plots were artificially contaminated with equal amount of used engine oil to represent a typical farmland oil spill. The plots were amended with various amount of processed sewage sludge i.e. 200 g 300 g and 400 g respectively. A pure culture of the bacteria was maintained on trypticase soy broth and was introduced into the sterile amended soil. The plots were watered twice daily for ten days. The degree of biodegradation and heavy metal content were assessed using standard procedures and the results obtained indicate a remarkable reduction in poly aromatic hydrocarbons PAHs total petroleum hydrocarbon TPH and heavy metal content.

  5. Gratuitous dechlorination of chloroethanes by methanogenic granular sludge

    NARCIS (Netherlands)

    Eekert, van M.H.A.; Stams, A.J.M.; Field, J.A.; Schraa, G.

    1999-01-01

    The dechlorinating activity of a methanogenic granular sludge from a methanol-fed upflow anaerobic sludge blanket reactor was investigated with chlorinated ethanes. This unadapted methanogenic consortium degraded all chloroethanes tested. The product formation rates decreased with the number of chlo

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    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...

  7. Urban Sewage Sludge, Sustainability, and Transition for Eco-City

    DEFF Research Database (Denmark)

    Ren, Jingzheng; Liang, Hanwei; Chan, Felix T. S.

    2017-01-01

    The treatment of urban sewage sludge is of vital importance for mitigating the risks of environmental contaminations, and the negative effects on human health. However, there are usually various different technologies for the treatment of urban sewage sludge; thus, it is difficult for decision-ma...

  8. Stabilization of organic sludges; Estabilizacion de fangos organicos

    Energy Technology Data Exchange (ETDEWEB)

    Dapena, J.L.

    1996-09-01

    The sludge or the waste coming from a depuration process (biological or no) are stabilized when its energy and carbon are low enough to be used in a new biological activity. the sludge stabilization must be guided to get the biggest possible reduction of its volatile matter. (Author)

  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)

    1997-12-31

    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. Application of forward osmosis on dewatering of high nutrient sludge.

    Science.gov (United States)

    Nguyen, Nguyen Cong; Chen, Shiao-Shing; Yang, Hung-Yin; Hau, Nguyen Thi

    2013-03-01

    A novel approach was designed to simultaneously apply low energy sludge dewatering and nutrient removal for activated sludge using forward osmosis (FO). In this study, the municipal wastewater sludge was spiked with different nutrient concentrations to evaluate FO dewatering performance. The results showed that sludge concentration reached 21,511 and 28,500mg/L after 28h from initial sludge concentration of 3000 and 8000mg/L with flow rate of 150mL/min. Moreover, nutrient and organic compounds in sludge solution were also successfully removed (around 96% of NH4(+)-N, 98% of PO4(3-)-P and 99% of dissolved organic carbon (DOC)) due to steric effect of FO membrane and multi barrier layer of sludge forming on membrane surface. Furthermore, the analysis from Scanning Electron Microscopy & Energy Dispersive X-ray Spectroscopy (SEM-EDS) images recorded that FO membrane was fouled by cake layer of sludge in the active layer and NaCl in the support layer.

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

    NARCIS (Netherlands)

    Hendrickx, T.L.G.

    2009-01-01

    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

  12. [Bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis].

    Science.gov (United States)

    Chang, Ming; Zhou, Shun-gui; Lu, Na; Ni, Jin-ren

    2006-07-01

    Feasibility of bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis was studied using sewage sludge as a raw material. The fermentation was also compared with conventional medium. Results showed that without any pretreatment, the nutrients contained in sewage sludge were almost sufficient for Bacillus thuringiensis growth, even with a rapid multiplicational rate. Higher viable cells and viable spores values were obtained earlier at 24 h, with 9.48 x 10(8) CFU x mL(-1) and 8.51 x 10(8) CFU x mL(-1) respectively, which was 12 hours earlier and nearly 20 percent higher than conventional medium. SEM of 36 h samples gave a clear phenomenon that the metabolizability in sludge was much faster with spores and crystals spreading around. The crystals in sludge seemed rather bigger and more regular. Also a better crystal protein yield of 2.80 mg x mL(-1) was observed in sludge medium compared to conventional medium at the end of fermentation. Sludge fermentation for Bacillus thuringiensis reduces the producing cost, and gives better fermentation capabilities. It's expected to be a new method for sludge disposal.

  13. Sludge residence time and membrane fouling: what is the connection?

    NARCIS (Netherlands)

    Van den Broeck, R.; Van Dierdonck, J.; Nijskens, P.; Dotremont, C.; Krzeminski, P.; van der Graaf, J.H.J.M.; van Lier, J.B.; Impe, J.F.M.; Smets, I.Y.

    2012-01-01

    Nowadays, waste activated sludge is more and more regarded as an energy source (through subsequent anaerobic digestion) or even as a potential source of fine chemicals (through subsequent fermentation processes). To this end, the organic content of the activated sludge should remain as high as possi

  14. 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...

  15. Drawing method and device of activated carbon sludge from drums

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Shigeru [Toshiba Corp., Kawasaki, Kanagawa (Japan); Kaji, Koichi

    1998-09-11

    Upon drawing out active sludge accumulated while being separated from supernatant water in a drum for containing active sludge generated as residues after the processing of washing liquid generated in a nuclear power plant, the sludge is stirred together with the supernatant water while being scraped off from the surface by using a stirring blade equipped with teeth. Then the sludge in the form of a slurry is drained by a highly viscous fluid transferring-pump. Then accumulated active carbon sludge can be supplied quantitatively as a mayonnaise-like slurry to a furnace. Alternatively, the supernatant water is drawn out at first from a drum, and sludge is discharged to the outside next by using screw blades disposed backward while scraping the sludge from the surface by rotating scraping teeth. With such procedures, there can be provided an advantageous point that the accumulated active carbon sludge can be supplied in a state of small lumps quantitatively to a furnace. (T.M.)

  16. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.

    1999-01-01

    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...

  17. Electrokinetic copper and iron migration in anaerobic granular sludge

    NARCIS (Netherlands)

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

    2006-01-01

    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 contaminat

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treat sewage sludge and simultaneously generate electricity. Stable power generation (145± 5 mW/m2, 470 Ω) was produced continuously from raw sewage sludge for 5.5 days. The maximum power density reached 190±5 mW/m2. The corresponding total...

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

    NARCIS (Netherlands)

    Hendrickx, T.L.G.

    2009-01-01

    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

  20. Electrokinetic copper and iron migration in anaerobic granular sludge

    NARCIS (Netherlands)

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

    2006-01-01

    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 contaminat

  1. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)

    ... (MLE) activated sludge process was used to treat refinery effluent from the industry. Pre-flocculation of the effluent was necessary to remove the bulk of the fats, ... the flocculated effluent, at a 15 d sludge age and 24 h hydraulic retention time.

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

    NARCIS (Netherlands)

    Temmink, B.G.; Klapwijk, A.

    2004-01-01

    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 days<

  3. IMPROVING THE GRAVITATIONAL PROPERTIES OF SEWAGE SLUDGE BY PRETREATMENTS

    Directory of Open Access Journals (Sweden)

    Ewelina Nowicka

    2015-01-01

    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.

  4. CMS Resistive plate Champers

    CERN Document Server

    Zainab, Karam

    2013-01-01

    There are many types of gas detectors which are used in CERN in LHC project, There is a main parts for the gas detectors which must be in all gas detectors types like Multiwire proportional chambers, such as the micromesh gaseous structure chamber (the MicroMegas), Gas-electron multiplier (GEM) detector, Resistive Plate Champers... Compact Muon Solenoid (CMS) experiment detecting muons which are powerful tool for recognizing signatures of interesting physics processes. The CMS detector uses: drift tube (DT), cathode strip chamber (CSC) and resistive plate chamber (RPC). Building RPC’s was my project in summer student program (hardware). RPC’s have advantages which are triggering detector and Excellent time resolution which reinforce the measurement of the correct beam crossing time. RPC’s Organized in stations :  RPC barrel (RB) there are 4 stations, namely RB1, RB2, RB3, and RB4  While in the RPC endcap (RE) the 3 stations are RE1, RE2, and RE3. In the endcaps a new starion will be added and this...

  5. Bio-Gas production from municipal sludge waste using anaerobic membrane bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. H.; Lee, S.

    2009-07-01

    A laboratory scale anaerobic membrane bioreactor (AnMBR) system for the bio-methane gas production was operated for 60 days with municipal sludge wastes as a sole carbon source. The AnMRR system utilized the external cross-flow membrane module and was equipped with on-line data acquisition which enables continuous monitoring of the performance of both bioreactor and membrane through the analyses of pH, temperature, gas production; permeate flow rate, and transmembrane pressure (TMP). Such a configuration also provides an efficient tool to study rapid variations of monitoring membrane pressure (TMP). (Author)

  6. Upflow Sludge Blanket Filtration (USBF: An Innovative Technology in Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    R Saeedi

    2010-06-01

    Full Text Available Background: A new biological domestic wastewater treatment process, which has been presented these days in activated sludge modification, is Upflow Sludge Blanket Filtration (USBF. This process is aerobic and acts by using a sludge blanket in the separator of sedimentation tank. All biological flocs and suspended solids, which are presented in the aeration basin, pas through this blanket. The performance of a single stage USBF process for treatment of domestic wastewater was studied in laboratory scale.Methods: The pilot of USBF has been made from fiberglass and the main electromechanical equipments consisted of an air com­pressor, a mixing device and two pumps for sludge return and wastewater injection. The wastewater samples used for the experiments were prepared synthetically to have qualitative characteristics similar to a typical domestic wastewater (COD= 277 mg/l, BOD5= 250 mg/l and TSS= 1 mg/l.Results: On the average, the treatment system was capable to remove 82.2% of the BOD5 and 85.7% of COD in 6 h hydraulic re­tention time (HRT. At 2 h HRT BOD and COD removal efficiencies dramatically reduced to 50% and 46.5%, respectively.Conclusion: Even by increasing the concentrations of pollutants to as high as 50%, the removal rates of all pollutants were re­mained similar to the HRT of 6 h.

  7. Comparison of phosphorus recovery from incinerated sewage sludge ash (ISSA) and pyrolysed sewage sludge char (PSSC).

    Science.gov (United States)

    Kleemann, Rosanna; Chenoweth, Jonathan; Clift, Roland; Morse, Stephen; Pearce, Pete; Saroj, Devendra

    2017-02-01

    This research compares and contrasts the physical and chemical characteristics of incinerator sewage sludge ash (ISSA) and pyrolysis sewage sludge char (PSSC) for the purposes of recovering phosphorus as a P-rich fertiliser. Interest in P recovery from PSSC is likely to increase as pyrolysis is becoming viewed as a more economical method of sewage sludge thermal treatment compared to incineration. The P contents of ISSA and PSSC are 7.2-7.5% and 5.6%, respectively. Relative to the sludge, P concentrations are increased about 8-fold in ISSA, compared to roughly 3-fold in PSSC. Both PSSC and ISSA contain whitlockite, an unusual form of calcium phosphate, with PSSC containing more whitlockite than ISSA. Acid leaching experiments indicate that a liquid/solid ratio of 10 with 30min contact time is optimal to release PO4-P into leachate for both ISSA and PSSC. The proportion of P extracted from PSSC is higher due to its higher whitlockite content. Heavy metals are less soluble from PSSC because they are more strongly incorporated in the particles. The results suggest there is potential for the development of a process to recover P from PSSC.

  8. Characterisation of adsorbents prepared by pyrolysis of sludge and sludge/disposal filter cake mix.

    Science.gov (United States)

    Velghe, I; Carleer, R; Yperman, J; Schreurs, S; D'Haen, Jan

    2012-05-15

    Copper and zinc removal from water (pH = 5.0) using adsorbents produced from slow and fast pyrolysis of industrial sludge and industrial sludge mixed with a disposal filter cake (FC), post treated with HCl, is investigated in comparison with a commercial adsorbent F400. The results show that a pseudo-second order kinetics model is followed. The Langmuir-Freundlich isotherm model is found to fit the data best. The capacity for heavy metal removal of studied adsorbents is generally better than that of commercial F400. The dominant heavy metal removal mechanism is cation exchange. Higher heavy metal removal capacity is associated with fast pyrolysis adsorbents and sludge/FC derived adsorbents, due to enhanced cation exchange. Improvement of Zn(2+) removal via 1 N HCl post-treatment is only effective when exchangeable cations of the adsorbent are substituted with H(+) ions, which boost the cation exchange capacity. Increase of temperature also enhances metal removal capacity. Fast pyrolysis sludge-based adsorbents can be reused after several adsorption-desorption cycles.

  9. Start-up of a thermophilic upflow anaerobic sludge bed (UASB) reactor with mesophilic granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lier, J.B. van; Grolle, K.C.F.; Lettinga, G. (Wageningen Agricultural Univ. (Netherlands). Dept. of Environmental Technology); Stams, A.J.M. (Wageningen Agricultural Univ. (Netherlands). Dept. of Microbiology); Conway de Macario, E. (New York State Dept. of Health, Albany, NY (United States). Wadsworth Center for Laboratories and Research State Univ. of New York, Albany, NY (United States). School of Public Health)

    1992-04-01

    Fast start-up of thermophilic upflow anaerobic sludge bed (UASB) reactors was achieved at process temperatures of 46, 55 and 64deg C, using mesophilic granular sludge as inoculum and fatty acid mixtures as feed. The start-up was brought about by increasing the temperature of mesophilic UASB reactors in a single step, which initially led to a sharp drop in the methane-production rate. Thereafter, stable thermophilic methanogenesis was achieved within a period of 1 or 2 weeks depending on the temperature of operation. Mesophilic granules functioned initially as effective carrier material for thermophilic organisms. However, long-term operation led to disintegration of the granules, resulting in wash-out of thermophilic biomass. The temperature optima for acetotrophic methanogenic activity of the sludges cultivated at 46, 55 and 64deg C, were similar, but differed significantly from the temperature optimum of the mesophilic inoculum. All the sludges examined were dominated by Methanothrix-like rods. These could be distinguished by antigenic fingerprinting into two subpopulations, one predominant at 36deg C and the other predominant at 46deg C and above. (orig.).

  10. Sludge Incineration. Multiple Hearth. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    Science.gov (United States)

    Klopping, Paul H.

    This lesson introduces the basics of sludge incineration and focuses on the multiple hearth furnace in accomplishing this task. Attention is given to component identification and function process control fundamentals, theory of incineration, safety, and other responsibilites of furnace operation. The material is rather technical and assumes an…

  11. Cometabolic degradation of organic wastewater micropollutants by activated sludge and sludge-inherent microorganisms.

    Science.gov (United States)

    Fischer, Klaus; Majewsky, Marius

    2014-08-01

    Municipal wastewaters contain a multitude of organic trace pollutants. Often, their biodegradability by activated sludge microorganisms is decisive for their elimination during wastewater treatment. Since the amounts of micropollutants seem too low to serve as growth substrate, cometabolism is supposed to be the dominating biodegradation process. Nevertheless, as many biodegradation studies were performed without the intention to discriminate between metabolic and cometabolic processes, the specific contribution of the latter to substance transformations is often not clarified. This minireview summarizes current knowledge about the cometabolic degradation of organic trace pollutants by activated sludge and sludge-inherent microorganisms. Due to their relevance for communal wastewater contamination, the focus is laid on pharmaceuticals, personal care products, antibiotics, estrogens, and nonylphenols. Wherever possible, reference is made to the molecular process level, i.e., cometabolic pathways, involved enzymes, and formed transformation products. Particular cometabolic capabilities of different activated sludge consortia and various microbial species are highlighted. Process conditions favoring cometabolic activities are emphasized. Finally, knowledge gaps are identified, and research perspectives are outlined.

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    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...

  13. Energy recovery from secondary pulp/paper-mill sludge and sewage sludge with supercritical water treatment.

    Science.gov (United States)

    Zhang, Linghong; Xu, Chunbao Charles; Champagne, Pascale

    2010-04-01

    Secondary pulp/paper-mill sludge (SPP) and sewage sludges (primary, secondary, and digested sewage sludges) were treated in supercritical water at temperatures ranging between 400 degrees Celsius and 550 degrees Celsius over 20-120 min for energy recovery. Low temperature and short reaction time favored the formation of heavy oil (HO) products, which were mainly composed of a variety of phenol and phenolic compounds, as well as some nitrogen-containing compounds, long-chain alkenes and alcohols, etc., with high gross calorific values (>36 MJ/kg). By contrast, the formation of synthetic gases, a mixture of hydrogen, carbon monoxide, carbon dioxide, methane, and other light hydrocarbons, were not significantly affected by reaction time but greatly enhanced with increasing temperature. The highest gas yield was obtained at 550 degrees Celsius, where 37.7 wt.% of the SPP (on dry basis) was converted into gases, with hydrogen yields as high as 14.5 mol H(2)/kg SPP (on a dry basis). In comparison to sewage sludges, SPP exhibited a greater capability for the production of HO and gases owing to its higher contents of volatiles and alkali metals, indicating a prospective utilization potential for SPP as a source of bio-energy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kroiss, Helmut

    2003-07-01

    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

  15. Rheological characterization of digested sludge by solid sphere impact.

    Science.gov (United States)

    Jiang, Jiankai; Wu, Jing; Poncin, Souhila; Li, Huai Z

    2016-10-01

    An impact method was applied to investigate the rheological characteristics of digested sludge and reveal its transient dynamics. A high-speed camera allowed visualizing the dynamic impact process and observing interaction between impacting sphere and targeted sludge. A damping oscillation was observed after the impact. The crater diameter followed an exponential function, while the crater depth varied as a logarithmic function of both sphere diameter and free fall height. Furthermore, the viscosity and elasticity of digested sludge were evaluated by establishing a simplified impact drag force model. The impact elastic modulus was consistent with the Young's modulus measured by a penetrometer. The impact viscosity was reasonable as the estimated impact shear stress was greater than the yield stress of digested sludge resulting in the formation of crater. The impact method offers an alternative way to reveal the viscoelasticity of digested sludge through a dynamic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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)

    1997-09-12

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    KETUSKY, EDWARD

    2006-04-20

    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.

  18. Can aquatic worms enhance methane production from waste activated sludge?

    Science.gov (United States)

    Serrano, Antonio; Hendrickx, Tim L G; Elissen, Hellen H J; Laarhoven, Bob; Buisman, Cees J N; Temmink, Hardy

    2016-07-01

    Although literature suggests that aquatic worms can help to enhance the methane production from excess activated sludge, clear evidence for this is missing. Therefore, anaerobic digestion tests were performed at 20 and at 30°C with sludge from a high-loaded membrane bioreactor, the aquatic worm Lumbriculus variegatus, feces from these worms and with mixtures of these substrates. A significant synergistic effect of the worms or their feces on methane production from the high-loaded sludge or on its digestion rate was not observed. However, a positive effect on low-loaded activated sludge, which generally has a lower anaerobic biodegradability, cannot be excluded. The results furthermore showed that the high-loaded sludge provides an excellent feed for L. variegatus, which is promising for concepts where worm biomass is considered a resource for technical grade products such as coatings and glues.

  19. Adsorption Characteristics of Remazol Black B on Anoxic Sludge

    Institute of Scientific and Technical Information of China (English)

    HUANG Man-hong; CHEN Liang; CHEN Dong-hui; CHEN Chao-peng

    2009-01-01

    The adsorption characteristics of Remazol Black B on anoxic sludge were investigated. The parameters, such as initial pH, sulphate concentration, and temperature,affecting the dye adsorption were studied. The adsorption data were analyzed with three adsorption isotherm models,namely Langmuir, Freudlich, and linear partition. The results showed that adsorption of Remazol Black B on the sterilized sludge reached equilibrium in 4 h. It also indicated that pH had significant effect on anoxic sludge adsorption behavior. The adsorption capacity of anoxic sludge decreased with the increase of pH value and the maximum adsorption capacity of dyes occurred at pH = 3. The adsorptive capacities increased with the decrease of temperature and increase of sulphate concentration. Results also indicated that the adsorption equilibrium of Remazol Black B on anoxic sludge could be well fitted by Freundlich model.

  20. Enhancement of activated sludge disintegration and dewaterability by Fenton process

    Science.gov (United States)

    Heng, G. C.; Isa, M. H.

    2016-06-01

    Municipal and industrial wastewater treatment plants produce large amounts of sludge. This excess sludge is an inevitable drawback inherent to the activated sludge process. In this study, the waste activated sludge was obtained from the campus wastewater treatment plant at Universiti Teknologi PETRONAS (UTP), Malaysia. Fenton pretreatment was optimized by using the response surface methodology (RSM) to study the effects of three operating conditions including the dosage of H2O2 (g H2O2/kg TS), the molar ratio of H2O2/Fe2+ and reaction time. The optimum operating variables to achieve MLVSS removal 65%, CST reduction 28%, sCOD 11000 mg/L and EPS 500 mg/L were: 1000 g H2O2/kg TS, H2O2/Fe2+ molar ratio 70 and reaction time 45 min. Fenton process was proved to be able to enhance the sludge disintegration and dewaterability.

  1. Combustion of Sewage Sludge as Alternative Fuel for Cement Industry

    Institute of Scientific and Technical Information of China (English)

    LI Fuzhou; ZHANG Wei

    2011-01-01

    The combustion of sewage sludge and coal was studied by thermogravimetric analysis.Both differential scanning calorimetric analysis and derivative thermogravimetric profiles showed differences between combustion of sewage sludge and coal, and non-isothermal kinetics analysis method was applied to evaluate the combustion process. Based on Coats-Redfem integral method, some reaction models were tested,the mechanism and kinetics of the combustion reaction were discussed. The results show that the combustion of sewage sludge is mainly in the Iow temperature stage, meanwhile the ignition temperature and Arrhenius activation energy are lower than that of coal. The combustion of sewage sludge has the advantage over coal in some aspects, thus sewage sludge can partly replace coal used as cement industry fuel.

  2. Immobilization of activated sludge using improved polyvinyl alcohol (PVA) gel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The OUR (oxygen uptake rate) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads was prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH4+-N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.

  3. Enzyme Activities in Waste Water and Activated Sludge

    DEFF Research Database (Denmark)

    Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

    1992-01-01

    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...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

  4. Research on sludge treatment and handle in urban and town wastewater treatment plants in Shanxi%对山西省城镇污水厂污泥处理处置的研究

    Institute of Scientific and Technical Information of China (English)

    郝晨光

    2011-01-01

    介绍了山西省城镇污水处理及污泥产生情况,归纳了国内外城镇污水厂污泥处理处置方式,并较为详细地论述了污泥处理处置的主要技术,进而初步确定了山西省污泥处理处置发展技术路线。%The paper introduces the sewage treatment and sludge formation in cities and towns in Shanxi,sums up the sludge treatment and handle ways in urban and town wastewater treatment plants at home and abroad,indicates the main technique of the sludge treatment and handle,and identifies the development technique line of the sludge treatment and handle in Shanxi.

  5. Localised Plate Motion on Venus

    Science.gov (United States)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  6. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  7. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  8. Dynamics of Shells and Fluid-Loaded Plates.

    Science.gov (United States)

    Wang, Zhang

    This thesis is composed of two parts. The first part is concerned with wave propagation on elastic structures in vacuum. An asymptotic approximation is obtained for the dispersion relation of flexural waves propagating in an infinite, flat plate, with material and/or geometric properties periodic in one direction. A matrix approach is proposed to investigate waves in circular cylindrical thin shells joined with circular plates. Both the general propagator matrix and S-matrix formalisms are presented, with emphasis on the latter. The second part is devoted to structures with ambient fluid loading. The Green's function for a fluid-loaded plate under line loading is expressed as a sum of five fluid-loaded plate waves and an acoustic wave with magnitude given by an infinite integral, similar to a branch cut integral. A scattering matrix approach is presented to solve wave propagation problems on fluid-loaded plates with attached ribs. The low frequency asymptotic dispersion relation for a fluid-loaded plate with infinite number of equally spaced identical ribs is derived, from which an equation of motion for the plate is inferred which is valid also at low frequencies.

  9. A Robust and Efficient Approach to License Plate Detection.

    Science.gov (United States)

    Yuan, Yule; Zou, Wenbin; Zhao, Yong; Wang, Xinan; Hu, Xuefeng; Komodakis, Nikos

    2017-03-01

    This paper presents a robust and efficient method for license plate detection with the purpose of accurately localizing vehicle license plates from complex scenes in real time. A simple yet effective image downscaling method is first proposed to substantially accelerate license plate localization without sacrificing detection performance compared with that achieved using the original image. Furthermore, a novel line density filter approach is proposed to extract candidate regions, thereby significantly reducing the area to be analyzed for license plate localization. Moreover, a cascaded license plate classifier based on linear support vector machines using color saliency features is introduced to identify the true license plate from among the candidate regions. For performance evaluation, a data set consisting of 3977 images captured from diverse scenes under different conditions is also presented. Extensive experiments on the widely used Caltech license plate data set and our newly introduced data set demonstrate that the proposed approach substantially outperforms state-of-the-art methods in terms of both detection accuracy and run-time efficiency, increasing the detection ratio from 91.09% to 96.62% while decreasing the run time from 672 to 42 ms for processing an image with a resolution of 1082×728 . The executable code and our collected data set are publicly available.

  10. Bulking sludge for PHA production: Energy saving and comparative storage capacity with well-settled sludge

    Institute of Scientific and Technical Information of China (English)

    Qinxue Wen; Zhiqiang Chen; Changyong Wang; Nanqi Ren

    2012-01-01

    Two acetate-fed sequencing batch reactors (SBR) were operated under an aerobic dynamic feeding (ADF) model (SBR#2) and with anaerobic phase before aerobic phase (SBR#1) to select mixed cultures with a high polyhydroxyalkanoates (PHA) storage response.Although kinetic selection based on storage response should bring about a predominance of floc-formers,a bulking sludge with storage response comparable to well-settled sludge was steadily established.An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability (SBR #1),however,due to the consequent increased feast/famine ratio,the performance of SBR #1,in terms of both the maximum PHB (polyhydroxybutyrate) cell content and △PHB,was lower than that of SBR #2.SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation.The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ac/(Cmol X.hr) and 0.18 Cmol Ac/(Cmol PHB.hr),respectively,resulting a yield of 0.45 Cmol PHB/(Cmol Ac) in SBR #2 in the culture enrichment phase.A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/(Cmol PHB.hr) was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation.The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge.Furthermore,the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage.

  11. SLUDGE BATCH 7B GLASS VARIABILITY STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Edwards, T.

    2011-10-25

    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

  12. Characterization of oily sludge from a Tehran oil refinery.

    Science.gov (United States)

    Heidarzadeh, Nima; Gitipour, Saeid; Abdoli, Mohammad Ali

    2010-10-01

    In this study, oily sludge samples generated from a Tehran oil refinery (Pond I) were evaluated for their contamination levels and to propose an adequate remediation technique for the wastes. A simple, random, sampling method was used to collect the samples. The samples were analyzed to measure Total petroleum hydrocarbon (TPH), polyaromatic hydrocarbon (PAH) and heavy metal concentrations in the sludge. Statistical analysis showed that seven samples were adequate to assess the sludge with respect to TPH analyses. The mean concentration of TPHs in the samples was 265,600 mg kg⁻¹. A composite sample prepared from a mix of the seven samples was used to determine the sludge's additional characteristics. Composite sample analysis showed that there were no detectable amounts of PAHs in the sludge. In addition, mean concentrations of the selected heavy metals Ni, Pb, Cd and Zn were 2700, 850, 100, 6100 mg kg⁻¹, respectively. To assess the sludge contamination level, the results from the analysis above were compared with soil clean-up levels. Due to a lack of national standards for soil clean-up levels in Iran, sludge pollutant concentrations were compared with standards set in developed countries. According to these standards, the sludge was highly polluted with petroleum hydrocarbons. The results indicated that incineration, biological treatment and solidification/stabilization treatments would be the most appropriate methods for treatment of the sludges. In the case of solidification/stabilization, due to the high organic content of the sludge, it is recommended to use organophilic clays prior to treatment of the wastes.

  13. Bio-remediation of a sludge containing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ayotamuno, M.J. [Agricultural and Environmental Engineering Department, Rivers State University of Science and Technology, Port Harcourt, P. M. B. 5080, Rivers State (Nigeria); Okparanma, R.N. [Agricultural and Environmental Engineering Department, Rivers State University of Science and Technology, Port Harcourt, P. M. B. 5080, Rivers State (Nigeria); Nweneka, E.K. [Agricultural and Environmental Engineering Department, Rivers State University of Science and Technology, Port Harcourt, P. M. B. 5080, Rivers State (Nigeria); Ogaji, S.O.T. [School of Engineering, Cranfield University, Bedfordshire MK43 0AL (United Kingdom)]. E-mail: s.ogaji@cranfield.ac.uk; Probert, S.D. [School of Engineering, Cranfield University, Bedfordshire MK43 0AL (United Kingdom)

    2007-09-15

    Bio-augmentation has been used as a bio-remediation option for hydrocarbon-contaminated, oily-sludge restoration. This sludge was obtained from the Bonny-Terminal Improvement Project (BTIP) for Bonny Island, near Port Harcourt, Nigeria. Its total hydrocarbon-content (THC) was 69,372 mg/kg of sludge. Three treatment reactors (X, Y and Z) and one control reactor (A) were charged with 1500 g of oily sludge and 250 g of agricultural soil (i.e. an oily sludge to soil ratio of 6:1), the mixture homogenized and allowed to settle for seven days before various CFUs were added to reactors X, Y and Z. Reactor A did not receive any bio-preparation. The agricultural soil served both as a nutrient and a microbe carrier. With regularly scheduled mixing and watering, the THC reduction in the oily sludge varied between 40.7% and 53.2% within two weeks as well as between 63.7% and 84.5% within six weeks of applying the bio-remediation. The CFU counts of the added bio-preparation varied between 1.2 x 12{sup 12} and 3.0 x 10{sup 12} CFU/g of sludge and decreased to 7.0 x 10{sup 11} CFU/g of sludge by the end of the sixth week. The pH of the degrading sludge fluctuated between 6.5 and 7.8 during the same period. When compared with the performance of the indigenous microbes in the control sample, the added bio-preparation evidently increased the THC reduction rate in the oily sludge.

  14. TBT and TPhT persistence in a sludged soil.

    Science.gov (United States)

    Marcic, Christophe; Le Hecho, Isabelle; Denaix, Laurence; Lespes, Gaëtane

    2006-12-01

    The persistence of tributyltin (TBT) and triphenyltin (TPhT) in soils was studied, taking into consideration the quantity of sewage sludge, TBT and TPhT concentrations in soil as well as the soil pH. The organotin compounds (OTC) were introduced into the soil via a spiked urban sludge, simulating agricultural practise. OTC speciation was achieved after acidic extraction of soil samples followed by gas chromatography-pulsed flame photometric analysis (GC-PFPD). Leaching tests conducted on a spiked sludge showed that more than 98% of TBT are sorbed on the sludge. TBT persistence in soil appeared to depend on its initial concentration in sludge. Thus, it was more important when concentration is over 1000 microg(Sn) kg(-1) of sludge. More than 50% of the initial TBT added into the soil were still present after 2 months, whatever the experimental conditions. The main degradation product appeared to be dibutyltin. About 90% of TPhT were initially sorbed on sludge, whatever the spiking concentration in sludge was. However, TPhT seemed to be quantitatively exchangeable at the solid/liquid interface, according to the leaching tests. It was also significantly degraded in sludged soil as only about 20% of TPhT remain present after 2 months, the monophenyltin being the main degradation product. pH had a significant positive effect on TBT and particularly TPhT persistence, according to the initial amounts introduced into the soil. Thus, at pH over 7 and triorganotin concentration over 100 microg(Sn) kg(-1), less than 10% of TBT but about 60% of TPhT were degraded. When the sludge was moderately contaminated by triorganotins (typically 50 microg(Sn) kg(-1) in our conditions) the pH had no effect on TBT and TPhT persistence.

  15. Predicting bioavailability of metals from sludge-amended soils.

    Science.gov (United States)

    Golui, Debasis; Datta, S P; Rattan, R K; Dwivedi, B S; Meena, M C

    2014-12-01

    We attempted to develop a protocol for fixing the maximum permissible limit of sludge in agricultural lands based on transfer of metals from sludge-amended soils to human food chain. For this purpose, spinach was grown as a test crop on acid and alkaline soils with graded doses of sludge (0, 1.12, 2.24, 4.48, 8.96, 17.9, 35.8, 71.6, 142 and 285 g kg(-1) of soil) in a pot experiment. Biomass yield of spinach was increased due to sludge application in both acid and alkaline soils. Among the chemical extractants, EDTA extracted the highest amount of metals from sludge-amended soil followed by diethylenetriaminepentaacetic acid (DTPA) and CaCl2. Elevated levels of Zn, Cu, Fe, Mn, Ni, Cd and Pb in spinach were observed due to sludge application over control. Application of sludge was more effective in increasing metal content in spinach grown on acid soil than alkaline soil. Solubility-free ion activity model as a function of pH, organic carbon and extractable metal was far more effective in predicting metal uptake by spinach grown on sludge-amended soils as compared to that of chemical extractants. Risk in terms of hazard quotient (HQ) for intake of metals through consumption of spinach by humans grown on sludge-treated soils was computed for different metals separately. In a 90-day pot experiment, safe rates of sludge application were worked out as 4.48 and 71.6 g kg(-1) for acid and alkaline soils, respectively.

  16. Polyphosphate Kinase from Activated Sludge Performing Enhanced Biological Phosphorus Removal†

    Science.gov (United States)

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

    2002-01-01

    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

  17. Effects of ultrasonic disintegration of excess sewage sludge.

    Science.gov (United States)

    Zielewicz, Ewa

    2016-10-01

    Breaking down sludge floc (sonodyspergation effect) and destruction of the cell membranes of microorganisms forming floc is a direct effect of ultrasonic disintegration of sludge excess. This results in release of organic material by liquid sludge (the sonolysis effect). Desired technological effects of the disintegration are: to shorten the hydrolytic phase of fermentation, to increase the production of biogas (source of renewable energy) and an increased mineralization (stability) of fermented sludge. The presented study demonstrates research covering thickened excess sludge of various physicochemical properties, collected from nine municipal sewage treatment plants. The sludge was subjected to ultrasonic disintegration using three differently constructed disintegrators and different proportions of sonification area. Direct effects of disintegration were monitored and recorded using selected indicators describing changes in the properties of sludge and increase of substance dispersed and dissolved in the supernatant liquid to be filtered. Studies have demonstrated that those (direct) effects of ultrasonic disintegration depend on the physicochemical properties of the sludge (foremost the concentration of dry solids) that determine their variable susceptibility to the disintegration methods. The direct effects also depend on optimal process conditions (which consist of the construction of the ultrasonic disintegrator), the geometric proportions of the sonication area and the operating parameters of disintegration (which could be appropriately matched to the characteristics of sludge). The most preferable results were obtained for ultrasonic disintegration of sludge with a dry matter concentration C 0 dry matter (C 0 = 2.0 %), which was sonicated in a reactor with a short transducer of the largest radiating surface area, as well as the lowest ratio between this area and area of reactor. The best effects of disagglomeration of flocks have corresponded with the

  18. Aluminum Manganese Molten Salt Plating

    Science.gov (United States)

    2006-06-01

    Dry fixture thoroughly with the air gun. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process...easily destroyed if blown with the air. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process and...especially careful to dry water out of crevices. 13. Carefully remove part from fixture. If residual plating solution is present at attachments points

  19. Optimization of operation conditions for preventing sludge bulking and enhancing the stability of aerobic granular sludge in sequencing batch reactors.

    Science.gov (United States)

    Zhou, Jun; Wang, Hongyu; Yang, Kai; Ma, Fang; Lv, Bin

    2014-01-01

    Sludge bulking caused by loss of stability is a major problem in aerobic granular sludge systems. This study investigated the feasibility of preventing sludge bulking and enhancing the stability of aerobic granular sludge in a sequencing batch reactor by optimizing operation conditions. Five operation parameters have been studied with the aim to understand their impact on sludge bulking. Increasing dissolved oxygen (DO) by raising aeration rates contributed to granule stability due to the competition advantage of non-filamentous bacteria and permeation of oxygen at high DO concentration. The ratio of polysaccharides to proteins was observed to increase as the hydraulic shear force increased. When provided with high/low organic loading rate (OLR) alternately, large and fluffy granules disintegrated, while denser round-shape granules formed. An increase of biomass concentration followed a decrease at the beginning, and stability of granules was improved. This indicated that aerobic granular sludge had the resistance of OLR. Synthetic wastewater combined highly and slowly biodegradable substrates, creating a high gradient, which inhibited the growth of filamentous bacteria and prevented granular sludge bulking. A lower chemical oxygen demand/N favored the hydrophobicity of granular sludge, which promoted with granule stability because of the lower diffusion rate of ammonia. The influence of temperature indicated a relatively low temperature was more suitable.

  20. Oxygen transfer dynamics and activated sludge floc structure under different sludge retention times at low dissolved oxygen concentrations.

    Science.gov (United States)

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

    2017-02-01

    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.

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

    NARCIS (Netherlands)

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

    1999-01-01

    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

  2. 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.

    2005-01-01

    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

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

    NARCIS (Netherlands)

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

    1999-01-01

    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 tr

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

    NARCIS (Netherlands)

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

    1999-01-01

    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 tr

  5. Sludge Treatment Evaluation: 1992 Technical progress

    Energy Technology Data Exchange (ETDEWEB)

    Silva, L J; Felmy, A R; Ding, E R

    1993-01-01

    This report documents Fiscal Year 1992 technical progress on the Sludge Treatment Evaluation Task, which is being conducted by Pacific Northwest Laboratory. The objective of this task is to develop a capability to predict the performance of pretreatment processes for mixed radioactive and hazardous waste stored at Hanford and other US Department of Energy (DOE) sites. Significant cost savings can be achieved if radionuclides and other undesirable constituents can be effectively separated from the bulk waste prior to final treatment and disposal. This work is initially focused on chemical equilibrium prediction of water washing and acid or base dissolution of Hanford single-shell tank (SST) sludges, but may also be applied to other steps in pretreatment processes or to other wastes. Although SST wastes contain many chemical species, there are relatively few constituents -- Na, Al, NO[sub 3], NO[sub 2], PO[sub 4], SO[sub 4], and F -- contained in the majority of the waste. These constituents comprise 86% and 74% of samples from B-110 and U-110 SSTS, respectively. The major radionuclides of interest (Cs, Sr, Tc, U) are present in the sludge in small molal quantities. For these constituents, and other important components that are present in small molal quantities, the specific ion-interaction terms used in the Pitzer or NRTL equations may be assumed to be zero for a first approximation. Model development can also be accelerated by considering only the acid or base conditions that apply for the key pretreatment steps. This significantly reduces the number of chemical species and chemical reactions that need to be considered. Therefore, significant progress can be made by developing all the specific ion interactions for a base model and an acid dissolution model.

  6. Wastewater and sludge reuse in agriculture

    Science.gov (United States)

    Kalavrouziotis, Ioannis

    2016-04-01

    The reuse of Municipal wastewaters (TMWW) for irrigation of crops, and of sludge for the amendment of soils, is a multidimensional disposal practice aiming at: (i) minimizing the environmental problems by releasing the pressure exerted by these two inputs on the environment, (ii) providing the growing plants with water and nutrients and (ii) improving soil fertility and productivity, The research work conducted in our University in relation to accomplishing a safe reuse has been focused on the study of the following aspects of reuse: (i) heavy metal accumulation in soils and plants with emphasis on their edible part. This aspect has been studied by conducting a series of experiments aiming at the study of the accumulation of heavy metals in soils, and in plant roots, stalks, leaves and fruits. The conclusions drawn so far with regard to the order of accumulation of heavy metals are: Roots>leaves>stalks>fruits ( edible parts) (ii) interactions between heavy metals, plant nutrients and soil chemical and physical properties. After the examinations of hundreds of interactions, and the development of a quantification of the interactions contribution, it was found that considerable quantities of heavy metals and nutrients are contributed to the soil and to various plant parts , emphasizing the important role of the elemental interactions in plants.(iii) assessment of soil pollution with heavy metals based on pollution indices, Three pollution Indices have been established by our research team and were proposed internationally for application in actual practice for the prediction of soil pollution due to long term reuse of wastewater and sludge. These indices are as follows: (a) Elemental pollution Index (EPI), (b) Heavy Metal Load (HML), and (c) Total Concentration Factor (TCF) and (iv) construction of a computer program for the control of the reuse of TMWW and sludge, and forecasting soil pollution due to accumulation of heavy metal by means of pollution indices.

  7. Glass-bead peen plating

    Science.gov (United States)

    Graves, J. R.

    1974-01-01

    Peen plating of aluminum, copper, and nickel powders was investigated. Only aluminum was plated successfully within the range of peen plating conditions studied. Optimum plating conditions for aluminum were found to be: (1) bead/powder mixture containing 25 to 35% powder by weight, (2) peening intensity of 0.007A as measured by Almen strip, and (3) glass impact bead diameter of at least 297 microns (0.0117 inches) for depositing-100 mesh aluminum powder. No extensive cleaning or substrate preparation is required beyond removing loose dirt or heavy oil.

  8. Electroless plating of thin gold films directly onto silicon nitride thin films and into micropores.

    Science.gov (United States)

    Whelan, Julie C; Karawdeniya, Buddini Iroshika; Bandara, Y M Nuwan D Y; Velleco, Brian D; Masterson, Caitlin M; Dwyer, Jason R

    2014-07-23

    A method to directly electrolessly plate silicon-rich silicon nitride with thin gold films was developed and characterized. Films with thicknesses plating free-standing ultrathin silicon nitride membranes, and we successfully plated the interior walls of micropore arrays in 200 nm thick silicon nitride membranes. The method is thus amenable to coating planar, curved, and line-of-sight-obscured silicon nitride surfaces.

  9. An Aerobic Digestion of Lime Sludge.

    Science.gov (United States)

    1982-07-01

    AD-AL1B 502 AllMy MEDICAL BIOENGINEERING RESEARCH AND DEVELOPMENT -- ETC F/6 13/2 ANAEROBIC DIGESTION OF LIME SLUDGE.U) JUL 82 EA KBYLINSKI, B A BELL...Applied for Digesters 1 and 3, Run 1 9262- 9313 .................................... 55 32. Volatile Solids Destroyed vs. Volatile Solids Applied for...CONCENTRATIONS Feed Effluent NH-N NH -N Reactor Run Julian Date mgfL mg/L 1 1 9261- 9313 100 203 1 1 9314-0008 58 243 2 1 9261-0008 72 147 3 1 9261

  10. Using Ecosan sludge for crop production

    CSIR Research Space (South Africa)

    Jimenez, B

    2006-01-01

    Full Text Available for crop production B. Jimenez*, A. Austin**, E. Cloete*** and C. Phasha*** *Engineering Institute, UNAM Apdo. Postal 70472; 04510 Coyoacan, Mexico D. F. (E-mail: bjimenezc@iingen.unam.mx) **CSIR Building and Construction Technology, Pretoria, South Africa... (septage). As a consequence, Ecosan sludge is often considered as septage for disposal purposes, therefore limiting its use in WaterScience&TechnologyVol54No5pp169?177QIWAPublishing2006 169 agriculture. At the present time, several developing countries...

  11. Analysis and modelling of predation on biofilm activated sludge process: Influence on microbial distribution, sludge production and nutrient dosage.

    Science.gov (United States)

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

    2016-11-01

    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.

  12. 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

    2014-01-01

    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, an occasion......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...

  13. The effect of flow equalisation and prefermentation on the sludge production and sludge characteristics in a BNR plant.

    Science.gov (United States)

    Mikola, A; Rautiainen, J; Kiuru, H

    2008-01-01

    A full-scale study investigated the influence of diurnal flow equalisation and prefermentation on the characteristics of sludge. The diurnal variations in the sludge concentration and the level of sludge blanket in the secondary clarifiers were evened out significantly with the use of an equalization basin. Stable conditions in the aeration basin and in the secondary clarifiers contributed to the improvements in the performance of the BNR plant. A decrease in the waste activated sludge production and an improvement in the settleability were also observed. The low WAS yield was attributed to the low yield COD compounds produced by the prefermentation, longer sludge age and constant conditions obtained by the flow equalisation. Some evidence was found that good settling properties would be related to the amount of suspended solids fed to the biological process as well as to the good performance of the biological process. IWA Publishing 2008.

  14. Tank 42 sludge-only process development for the Defense Waste Processing Facility (DWPF)

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D.P.

    2000-03-22

    Defense Waste Processing Facility (DWPF) requested the development of a sludge-only process for Tank 42 sludge since at the current processing rate, the Tank 51 sludge has been projected to be depleted as early as August 1998. Testing was completed using a non-radioactive Tank 42 sludge simulant. The testing was completed under a range of operating conditions, including worst case conditions, to develop the processing conditions for radioactive Tank 42 sludge. The existing Tank 51 sludge-only process is adequate with the exception that 10 percent additional acid is recommended during sludge receipt and adjustment tank (SRAT) processing to ensure adequate destruction of nitrite during the SRAT cycle.

  15. Intermittent plate tectonics?

    Science.gov (United States)

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  16. VISAS AND GREEN PLATES

    CERN Multimedia

    2000-01-01

    From 3 April 2000, all questions relating to visa requests for Switzerland, France, or Russia for a member of the personnel must be addressed to Ms. Agnita Querrou (telephone 72838, office 5-2-019, e-mail Agnita.Querrou@cern.ch).The Users' Office continues to deal with requests for letters of invitation and questions concerning visas for users in EP Division.Questions relating to removals, requests for green plates, to privileges of members of the personnel and to the importation of vehicles are still dealt with by Ms Zuzana Miller (telephone 79257, office 33-1-017, e-mail Zuzana.Muller@cern.ch) and Ms Joëlle Belleman (telephone 73962, office 33-1-019, e-mail Joelle.Belleman@cern.ch).

  17. ADOPT: A tool for automatic detection of tectonic plates at the surface of convection models

    Science.gov (United States)

    Mallard, C.; Jacquet, B.; Coltice, N.

    2017-08-01

    Mantle convection models with plate-like behavior produce surface structures comparable to Earth's plate boundaries. However, analyzing those structures is a difficult task, since convection models produce, as on Earth, diffuse deformation and elusive plate boundaries. Therefore we present here and share a quantitative tool to identify plate boundaries and produce plate polygon layouts from results of numerical models of convection: Automatic Detection Of Plate Tectonics (ADOPT). This digital tool operates within the free open-source visualization software Paraview. It is based on image segmentation techniques to detect objects. The fundamental algorithm used in ADOPT is the watershed transform. We transform the output of convection models into a topographic map, the crest lines being the regions of deformation (plate boundaries) and the catchment basins being the plate interiors. We propose two generic protocols (the field and the distance methods) that we test against an independent visual detection of plate polygons. We show that ADOPT is effective to identify the smaller plates and to close plate polygons in areas where boundaries are diffuse or elusive. ADOPT allows the export of plate polygons in the standard OGR-GMT format for visualization, modification, and analysis under generic softwares like GMT or GPlates.

  18. WIPP WAC Equivalence Support Measurements for Low-Level Sludge Waste at Los Alamos National Laboratory - 12242

    Energy Technology Data Exchange (ETDEWEB)

    Gruetzmacher, Kathleen M.; Bustos, Roland M.; Ferran, Scott G.; Gallegos, Lucas E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lucero, Randy P. [Pajarito Scientific Corporation, Santa Fe, New Mexico 87507 (United States)

    2012-07-01

    three source tubes seen in debris PDP drums. Available line sources (Eu-152) were placed in the spiral tubes to further accomplish the desired uniform distribution of radionuclides. The standard PDP drum (PDP matrix drum 005) and PDP sources were used to determine the lower limits of detection (LLD) and TMU. Analysis results for the sludge drum matrix case for two HPGe detectors were tabulated and evaluated. NNSS has accepted the methodology and results of the measurements towards demonstrating equivalence to CBFO certified systems. In conclusion, the WES-WGS and CMR-OPS gamma spectroscopy teams at LANL have defined and performed measurements that serve to establish and demonstrate equivalency with the processes used by CBFO certified NDA systems. The supplemental measurements address four key areas in Appendix A of DOE/WIPP-02-3122: Annual Calibration Confirmation and Performance Check measurements; LLD determination; and TMU definition. For these measurements the containers, matrices and activity loadings are selected to represent items being assayed in real LLW cases. The LLD and the TMU bounding measurements are to be performed one time and will not be required to be repeated in future campaigns. The annual calibration and performance check measurements were performed initially and planned to repeat in annual campaigns in order to maintain NNSS certification. PDP sources and a PDP sludge drum as well as Eu-152 line sources and a spiral sludge drum were used for the measurements. In all cases, the results for accuracy and precision (%R and %RSD, respectively) were within allowable ranges as defined by the WIPP PDP program. LLD (or MDC) results were established for all the ten WIPP reportable radionuclides and U-235, and the MDC for Pu-239 was established in all cases to be well under 100 nCi/g. Useful results for reducing estimated uncertainties were established and an interesting unexpected case of high bias was observed and will be applied toward this end. (authors)

  19. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  20. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  1. Development of Intermediate Cooling Technology and Its Control for Two-Stand Plate Rolling

    Directory of Open Access Journals (Sweden)

    Fei Zhang

    2016-01-01

    Full Text Available In a plate rolling production line, thermomechanically controlled processing is critical for plate quality. In this paper, a set of intermediate cooling equipment of a two-stand plate mill with super density nozzles, medium pressure, and small flow is developed. Based on a simplified dynamic model, a cooling control scheme with combined feedforward, feedback, and adaptive algorithms is put forward. The new controlled rolling process and the highly efficient control system improve the controlled rolling efficiency by an average of 17.66%. The proposed intermediate cooling system can also effectively inhibit the growth of austenite grain, improve the impact toughness and yield strength of Q345B steel plate, reduce the formation of secondary oxide scale on the plate surface and the chromatic aberration of the plate surface, and greatly improve the surface quality of the steel plate.

  2. Si microchannel plates for image intensification

    Science.gov (United States)

    Smith, Arlynn W.; Beetz, Charles P., Jr.; Boerstler, Robert W.; Winn, D. R.; Steinbeck, John W.

    2000-11-01

    Glass microchannel plates (MCPs) have been in use by numerous manufactuers in a variety of electron multiplication applications. Conventional fabrication of MCPs follow the lines of glass drawing and etching technology. Core and clad glass are drawn together, stacked, drawn again, and finally stacked in the desired pattern. The soluble core is removed with wet chemical processing. These techniques are beginning to run into their feasible limits in terms of channel size, open area ratio, uniformity, and material issues. A strong desire exists to fabricate MCPs with accepted lithographic techniques using Si as the base material to improve uniformity and throughput. Open area ratios of as high as 95% have been achieved using lithography. However, attempts to meet other channel plate characteristics met with little success due to thermal runaway or arcing during operation, high voltage is required for electron gain. Processing improvements have lead to the complete oxidation of the Si matrix eliminating the conducting Si in the channel walls of the Si MCPs allowing high voltages to be supported. Complete oxidation of the Si to silica allows processing temperatures high than conventional glass matrices can withstand. This fact allows for high temperature growth of conductive and secondary emissive materials on the channel walls of the structure. Si MCPs with gain have now been fabricated and tested with voltages comparable to conventional glass MCPs. Channel plate characteristics such as operating voltage, strip current, and gain for Si MCPs will be presented and compared to glass MCPs.

  3. SLUDGE WASHING AND DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS FOR SLUDGE BATCH 5 QUALIFICATION

    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

    2008-11-10

    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

  4. Plate tectonics, damage and inheritance.

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  5. Measure Lines

    Science.gov (United States)

    Crissman, Sally

    2011-01-01

    One tool for enhancing students' work with data in the science classroom is the measure line. As a coteacher and curriculum developer for The Inquiry Project, the author has seen how measure lines--a number line in which the numbers refer to units of measure--help students not only represent data but also analyze it in ways that generate…

  6. [Adsorption of a dye by sludges and the roles of extracellular polymeric substances].

    Science.gov (United States)

    Kong, Wang-sheng; Liu, Yan

    2007-12-01

    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).

  7. 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.

    Science.gov (United States)

    Ara, E; Sartaj, M; Kennedy, K

    2014-12-01

    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.

  8. ISOTHERMAL PYROLYSIS OF KRAFT PULP MILL SLUDGE

    Directory of Open Access Journals (Sweden)

    Syamsudin Syamsudin

    2014-12-01

    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.

  9. Casimir Effect for Dielectric Plates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We generalize Kupisewska method to the three-dimensional system and another derivation of the Casimir effect between two dielectric plates is presented based on the explicit quantization of the electromagnetic field in the presence of dielectrics, where the physical meaning of "evanescent mode" is discussed. The Lifshitz's formula is rederived perfect metallic plates will the evanescent modes become unimportant.

  10. Micro-channel plate detector

    Science.gov (United States)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  11. Gold plating on spectacle frames.

    Science.gov (United States)

    Kenny, I; Mitchell, J W; Walsh, G

    1997-05-01

    An investigation was carried out into the thickness and standard of application of the plating and lacquer coatings applied to three metal spectacle frames. All conform to BS 6625 (1991) for plating thickness, but there was considerable variation in regularity and porosity.

  12. CFD simulation of anaerobic digester with variable sewage sludge rheology.

    Science.gov (United States)

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

    2013-09-01

    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.

  13. Formation, characterization and mathematical modeling of the aerobic granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Bing-Jie [Queensland Univ., Brisbane, QLD (Australia). Advanced Water Management Centre

    2013-07-01

    Reports on successful aerobic granulation of sludge in pilot-scale reactor for treatment of low-strength municipal wastewater and identifies the key factors responsible for this process. Develops comprehensive models for sludge granulation, microbial interactions and microbial products formation to provide insights into the dynamics of all the soluble and solid components in aerobic granular sludge system. Demonstrates accelerated start-up and optimization of the anaerobic ammonia oxidation process by seeding the reactor with aerobic granules. Aerobic granular sludge technology will play an important role as an innovative technology alternative to the present activated sludge process in industrial and municipal wastewater treatment in the near future. Intended to fill the gaps in the studies of aerobic granular sludge, this thesis comprehensively investigates the formation, characterization and mathematical modeling of aerobic granular sludge, through integrating the process engineering tools and advanced molecular microbiology. The research results of this thesis contributed significantly to the advance of understanding and optimization of the bacterial granulation processes, the next generation of technology for cost-effective biological wastewater treatment.

  14. Municipal Sewage Sludge Drying Treatment by an Composite Modifier

    Directory of Open Access Journals (Sweden)

    Na Wei

    2012-01-01

    Full Text Available A sludge composite modifier (SCM which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The results showed that the optimum ratio of modifier component was slag/cement clinker/dihydrate gypsum = 0.64/0.292/0.068 and the moisture content of SCM-stabilized sludge decreased with the increasing material content and extending curing time. Besides, the experimental results showed that optimized SCM behaved better than quicklime and Portland cement in sludge semi-drying and XRD analysis revealed that the main hydrated product of stabilization was ettringite, which played an important role in the effective drying process. Sewage sludge stabilized using SCM could be used as an effective landfill cover.

  15. Hazards from pathogenic microorganisms in land-disposed sewage sludge.

    Science.gov (United States)

    Straub, T M; Pepper, I L; Gerba, C P

    1993-01-01

    Sewage sludge is a complex mixture of organic and inorganic compounds of biological and mineral origin that are precipitated from wastewater and sewage during primary, secondary, and tertiary sewage treatment. Present in these sludges are significant numbers of microorganisms that include viral, bacterial, protozoan, fungal, and helminth pathogens. The treatment of sludge to reduce biochemical oxygen demand, solids content, and odor is not always effective in reducing numbers of pathogens. This becomes a public health concern because the infectious dose for some of these pathogens may be as low as 1 particle (virus) to 50 organisms (Giardia). When sludge is applied to land for agricultural use and landfill compost, these pathogens can survive from days (bacteria) to months (viruses) to years (helminth eggs), depending on environmental conditions. Shallow aquifers can become contaminated with pathogens from sludge and, depending on groundwater flow, these organisms may travel significant distances from the disposal site. Communities that rely on groundwater for domestic use can become exposed to these pathogens, leading to a potential disease outbreak. Currently, methods to determine the risk of disease from pathogens in land-disposed sludge are inadequate because the sensitivity of pathogen detection is poor. The application of recombinant DNA technology (gene probes and polymerase chain reaction) to environmental samples may provide increased sensitivity for detecting specific pathogens in land-disposed sludge and greatly improved risk assessment models for our exposure to these sources of pathogens.

  16. Environmentally safe management of radioactive and toxic sludges

    Energy Technology Data Exchange (ETDEWEB)

    Shingarev, N.E.; Mukhin, I.V.; Polyakov, A.S.; Raginsky, L.S.; Semenov, B.A. [SSC RF, A.A. Bochvar All-Russia, Research Institute of Inorganic Materials, VNIINM (Russian Federation)

    2000-07-01

    Toxic industrial wastes constitute a significant part of Russian natural environment. The most reliable route to provide the long-term ecologic safety involves removal of toxicants or radioactive substances from polluted sites. With a view of processing toxic and radioactive sludges available in reservoirs, a process flowsheet is suggested that comprises the operations of sludge concentration, dehydration and granulation.Flocculation is an operation required to concentrate a solid phase. Polyacrylamide (PAA) and hydrolyzed PAA (HPAA) are standard flocculating agents used in the processing of sludges coming from storage facilities of radioactive wastes. HPAA is less efficient and it is shown that the optimized concentration of PAA is 4 mg/g solid. Flotation agents are used to extract the solid phase of sludges, it is shown that the process of extraction has to be carried out in 2 stages, the first flotation cycle with a Ph value between 7.5 and 9.5 and the second with a Ph adjustment to 3.5-6.0.The cake resulting from the sludge filtration has poor technological properties, it is advisable to produce a granular material. Hydro-granulation using hydrophobic flocculating agents may be implemented immediately after sludge concentration. The other granulation technique involves the sol-gel process used to incorporate sludge into a ceramic (aluminium oxide) matrix.

  17. Behavior of radioactive materials and safety stock of contaminated sludge.

    Science.gov (United States)

    Tsushima, Ikuo

    2017-01-28

    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%.

  18. Physiological adaptation of growth kinetics in activated sludge.

    Science.gov (United States)

    Friedrich, M; Takács, I; Tränckner, J

    2015-11-15

    Physiological adaptation as it occurs in bacterial cells at variable environmental conditions influences characteristic properties of growth kinetics significantly. However, physiological adaptation to growth related parameters in activated sludge modelling is not yet recognised. Consequently these parameters are regarded to be constant. To investigate physiological adaptation in activated sludge the endogenous respiration in an aerobic degradation batch experiment and simultaneous to that the maximum possible respiration in an aerobic growth batch experiment was measured. The activated sludge samples were taken from full scale wastewater treatment plants with different sludge retention times (SRTs). It could be shown that the low SRT sludge adapts by growth optimisation (high maximum growth rate and high decay rate) to its particular environment where a high SRT sludge adapts by survival optimization (low maximum growth rate and low decay rate). Thereby, both the maximum specific growth rate and the decay rate vary in the same pattern and are strongly correlated to each other. To describe the physiological state of mixed cultures like activated sludge quantitatively a physiological state factor (PSF) is proposed as the ratio of the maximum specific growth rate and the decay rate. The PSF can be expressed as an exponential function with respect to the SRT.

  19. SLUDGE RETRIEVAL FROM HANFORD K WEST BASIN SETTLER TANKS

    Energy Technology Data Exchange (ETDEWEB)

    ERPENBECK EG; LESHIKAR GA

    2011-01-13

    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.

  20. Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions.

    Science.gov (United States)

    Naz, Iffat; Batool, Syeda Ain-ul; Ali, Naeem; Khatoon, Nazia; Atiq, Niama; Hameed, Abdul; Ahmed, Safia

    2013-08-01

    The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90-99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, indicating a positive shift from pathogenic to beneficial microbial community. While most probable number index of fecal coliforms and E. coli in the sludge showed more reduction (98 and 99 %) under aerobic as compare to anaerobic conditions (86 and 91 %) after 9 weeks of biofilm formation on PS cubes. Correspondingly, the decreasing levels of chemical oxygen demand and biochemical oxygen demand (up to 73 %) showed signs of sludge digestion. Scanning electron microscope coupled with energy dispersive X-ray spectroscope revealed nature of PS media containing high carbon content. However, biofilm development proved to be involved in the biochemical transformation of the PS medium as indicated by Fourier transform infrared spectroscopy.