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1

Dewatering of mineral slurries  

US Patent & Trademark Office Database

Mineral slurries are effectively dewatered by a process employing an aminofunctional silicone emulsion as a dewatering aid. The process provides for mixing the dewatering aid with the aqueous mineral slurry and thereafter separating the treated slurry into a mineral portion and an aqueous portion. The use of the aminofunctional silicones provide for reduced moisture content and/or increased production rate in a mineral slurry dewatering process.

Cooper; Ian V. (Georgetown, CA)

1985-06-25

2

Sludge dewatering technology  

Microsoft Academic Search

Sludge is an environmental dilemma for many industries, from the process and power industries to the paint and paper industries. Sludge problems exist in production pits and tank bottoms, in plating plants and sewage treatment plants. Flue gas desulfurization systems create enormous amounts of sludge. Dewatering sludge is a multi-billion dollar industry. Sludge dewatering is rarely a single-step process. It

Weismantel

1993-01-01

3

Energy demand in sludge dewatering  

Microsoft Academic Search

This work investigates the energy required to dewater a suspension, i.e., activated sludge dewatered by centrifugation or consolidation. Total energy input to the suspension from the dewatering device, bond strength between adjacent water and solid surface, and intra-cake friction loss were evaluated for original and flocculated sludges. In centrifugal dewatering, most energy input during the initial stage was consumed by

C. P. Chu; D. J. Lee; C. Y. Chang

2005-01-01

4

Vacuum Dewatering During Paper Manufacturing  

Microsoft Academic Search

Water removal during paper making is one of the most energy-intensive and capital-intensive processes. Vacuum dewatering is one of the intermediate stages of water removal on the paper machine where the compressible, wet mat is dewatered using applications of higher vacuum. A summary of the various stages of dewatering on the paper machine wire and the potential mechanisms of dewatering

S. Ramaswamy

2003-01-01

5

Composting Dewatered Sewage Sludge.  

National Technical Information Service (NTIS)

The test program described was designed to obtain the following basic information concerning the composting of a combination of primary and secondary dewatered sewage sludges: (1) effect of mixing; (2) effect of moisture content; (3) effect of recycling; ...

1973-01-01

6

Advanced Dewatering Systems Development  

SciTech Connect

A new fine coal dewatering technology has been developed and tested in the present work. The work was funded by the Solid Fuels and Feedstocks Grand Challenge PRDA. The objective of this program was to 'develop innovative technical approaches to ensure a continued supply of environmentally sound solid fuels for existing and future combustion systems with minimal incremental fuel cost.' Specifically, this solicitation is aimed at developing technologies that can (i) improve the efficiency or economics of the recovery of carbon when beneficiating fine coal from both current production and existing coal slurry impoundments and (ii) assist in the greater utilization of coal fines by improving the handling characteristics of fine coal via dewatering and/or reconstitution. The results of the test work conducted during Phase I of the current project demonstrated that the new dewatering technologies can substantially reduce the moisture from fine coal, while the test work conducted during Phase II successfully demonstrated the commercial viability of this technology. It is believed that availability of such efficient and affordable dewatering technology is essential to meeting the DOE's objectives.

R.H. Yoon; G.H. Luttrell

2008-07-31

7

Fine coal dewatering  

Microsoft Academic Search

The run-of-mine coals in the U.S. being fed to coal cleaning plants have become increasingly finer due to the adoption of modern, mechanized mining methods, and economics are dictating that finer fractions, as well as the coarser fractions, be cleaned. Traditional dewatering methods (vacuum disc filters and centrifuges) are proving inadequate for preparing fine refuse for disposal or fine coal

R. W. Row; J. R. Cavalet

1984-01-01

8

PILOT INVESTIGATION OF SECONDARY SLUDGE DEWATERING ALTERNATIVES  

EPA Science Inventory

A pilot investigation of biological sludge thickening and dewatering alternatives, including pressure filtration, precoat vacuum filtration, filter belt pressing, capillary suction, dewatering, gravity filtration, centrifugation, and ultrafiltration has been conducted on waste ac...

9

Review of Phosphatic Clay Dewatering Research.  

National Technical Information Service (NTIS)

This Bureau of Mines study surveys the current state of technology and the various research efforts that have been undertaken to dewater the dilute phosphatic clays generated in the production of phosphate rock. The research described includes early dewat...

W. E. Pittman J. T. McLendon J. W. Sweeney

1984-01-01

10

Process for dewatering coal slurries  

SciTech Connect

The invention concerns a method for optimization of the coal slurry dewatering process. Through a regulation of the fine grain content, it is possible to keep the filter cake at a constant level and thus to maximize the dewatering process. A separation of the slurry into a predominantly relatively fine grain fraction and a relatively coarse grain fraction, with the division point being between about 0.03 and 0.15 mm, is carried out, with a formation of a coal agglomerate from the fine grain fraction, and a dehydration of both the coarse grain fraction and the coal agglomerate from the fine grain fraction.

Blankmeister, W.; Bogenschneider, B.; Kohling, R.; Kubitza, H.; Leininger, D.

1981-03-24

11

CENTRIFUGAL DEWATERING OF FILTER CAKE  

Microsoft Academic Search

The dewatering of filter cake in a redundant Broadbent batch centrifuge was investigated. With some minor modifica- tions, the machine reduced the mass of the incoming cake feed by about 30 percent. At the same time approximately half the pol in the filter cake feed was recovered in the centrate return. The potential gains which could be realised from the

A. B. RAVN; G. R. E. LIONNET

12

The effect of digestion and dewatering on sudden increases and regrowth of indicator bacteria after dewatering.  

PubMed

Several investigators have reported higher densities of indicator bacteria after dewatering of anaerobically digested biosolids. The increases appear to occur at two points in the biosolids process: the first, referred to as "sudden increase", occurs immediately after dewatering; the second, "regrowth", occurs during storage over longer periods. The objectives of this study were to examine the effect of digestion and dewatering processes on sudden increase and regrowth of fecal coliform and E. coli. Samples were collected from five thermophilic and five mesophilic digestion processes, with either centrifuge or belt filter press dewatering. Sudden increase typically was observed in the thermophilic processes with centrifuge dewatering and was not observed in the mesophilic processes with either centrifuge or belt filter press dewatering. Regrowth was observed in both thermophilic and mesophilic processes with centrifuge dewatering but not belt filter press dewatering. PMID:22073724

Chen, Yen-Chih; Murthy, Sudhir N; Hendrickson, Donald; Araujo, Gordon; Higgins, Matthew J

2011-09-01

13

Dewatering studies of fine clean coal  

SciTech Connect

The main objective of the present research program is to study and understand dewatering characteristics of ultrafine clean coal obtained using the advanced column flotation technique from the Kerr-McGee's Galatia preparation plant fine coal waste stream. It is also the objective of the research program to utilize the basic study results, i.e., surface chemical, particle shape particle size distribution, etc., in developing a cost-effective dewatering method. The ultimate objective is to develop process criteria to obtain a dewatered clean coal product containing less that 20 percent moisture, using the conventional vacuum dewatering equipment. (VC)

Parekh, B.K.

1991-01-01

14

DESIGN MANUAL: DEWATERING MUNICIPAL WASTEWATER SLUDGES  

EPA Science Inventory

This manual discusses the many factors involved in selecting and designing dewatering equipment for organic sludges produced during primary and secondary municipal wastewater treatment. ive-step approach is outlined for the selection and design of the dewatering equipment for eit...

15

Sewage sludge dewatering using flowing liquid metals  

DOEpatents

This invention relates generally to the dewatering of sludge, and more particularly to the dewatering of a sewage sludge having a moisture content of about 50 to 80% in the form of small cellular micro-organism bodies having internally confined water.

Carlson, L.W.

1985-08-30

16

Dewatering behavior of sewage screenings.  

PubMed

Screenings from municipal sewage treatment plants have increased in importance in recent years, particularly in Germany, where laws prohibit depositing of screenings in landfill. This paper presents basic investigations of sewage screenings, especially the structure and dewatering behavior. Two standard experiments are conducted. First, the relationship between pressure and water content is determined. Secondly the flow resistance as a function of pressure is evaluated. The results help to derive simulation models in order to understand how the material behaves inside a wash press. PMID:23374399

Gregor, H; Rupp, W; Janoske, U; Kuhn, M

2013-01-29

17

Dewatering of biomaterials by mechanical thermal expression  

SciTech Connect

Dewatering by mechanical thermal expression (MTE) for a range of materials is explored using a laboratory-scale MTE compression-permeability cell. It is shown that MTE can be used to effectively dewater a range of biomaterials including lignite, biosolids, and bagasse. The underlying dewatering mechanisms relevant to MTE, namely (1) filtration of water expelled due to thermal dewatering, (2) consolidation, and (3) flash evaporation, are discussed. At lower temperatures, the dominating dewatering mechanism is consolidation, but with increasing temperature, thermal dewatering becomes more important. A major focus is an investigation of the effects of processing parameters, including temperature (20 to 200{sup o}C) and pressure (1.5 to 24 MPa), on material permeability, a fundamental dewatering parameter. It is illustrated that permeability is particularly dependent on the processing temperature, owing to changes in both the material structure and the water properties. In addition, a comparison of permeability in the direction of applied force (axial) and perpendicular to the direction of applied force (radial) is presented. It is shown that, due to alignment of particles under the applied force, the permeability and, hence, rate of water removal in the radial direction is greater than in the axial direction. SEM micrographs are presented to illustrate the particle alignment.

Clayton, S.A.; Scholes, O.N.; Hoadley, A.F.A.; Wheeler, R.A.; McIntosh, M.J.; Huynh, D.Q. [Monash University, Clayton, Vic. (Australia). Dept. of Chemical Engineering

2006-07-01

18

Dewatering Florida Phosphate Pebble Rock Slime by Freezing Techniques.  

National Technical Information Service (NTIS)

Freezing to dewater typical Florida phosphate rock slime as demonstrated in laboratory tests appeared to have potential commercial use because of indicated moderate energy requirements, good compaction of dewatered solids, and effective recovery of usable...

E. W. Collins I. L. Feld M. H. Stanczyk

1971-01-01

19

An innovative concept for dewatering hydro plants  

SciTech Connect

A floating bulkhead that works much like an overhead garage door can be a versatile, reusable, and cost-effective tool for dewatering unit intakes or gated spillway bays at hydroelectric facilities. The floating bulkhead consists of a number of individual floating caissons that can be installed separately by stacking them one on top of another, or pinned together with hinges and installed as a unit. A caisson consists of one or more flotation compartments and a water-filled compartment to sink or float it. Each caisson is lowered into the reservoir from an accessible location, such as a boat launch, and towed into position by a boat. The floating bulkhead is especially suited to structures that have no provisions for dewatering or where the existing dewatering structures are no longer serviceable, or in situations where cranes are not available to install stoplogs.

Lux, F. III; Bakken, J.R. (Ayres Associates, Eau Claire, WI (United States))

1992-12-01

20

Mechanical properties of dewatered sewage sludge  

Microsoft Academic Search

The mechanical properties of dewatered, anaerobically digested sewage sludge were determined from soil laboratory tests. The sludge material is largely composed of organic clay sized-particles, a sizable fraction of which is in an active state of biological digestion which can continue over many years under field conditions. Moderately digested sludge material was found to have a typical specific gravity of

Brendan C. O’Kelly

2005-01-01

21

Chemical Primary Sludge Thickening and Dewatering.  

National Technical Information Service (NTIS)

This report presents the results of a ten month study of the thickening and dewatering characteristics of chemical-primary sludges. Alum-primary and ferric-primary sludges were produced in parallel trains of a pilot plant operated using a municipal wastew...

D. Di Gregorio J. B. Ainsworth K. J. Mounteer

1979-01-01

22

Composition and Dewatering Properties of Biological Sludges.  

National Technical Information Service (NTIS)

This study was designed to determine the role of biopolymer in sludge dewatering. Free biopolymer was measured as the high molecular weight fraction (excluded by Sephadex G-50 gell) in the supernatant liquor fraction. The study showed that as the fraction...

J. T. Novak B. D. Moore

1982-01-01

23

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

PubMed

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. PMID:23379170

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

2012-12-01

24

Dewatering studies of fine clean coal  

SciTech Connect

Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop the process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. During the last year's effort, it was reported that a combination of metal ion and surfactant provided a 22 percent moisture filter cake.

Parekh, B.K.

1991-01-01

25

Effects of Vacuum Filtration Parameters on Ultrafine Coal Dewatering  

Microsoft Academic Search

Coal fines (-0.6 mm) are often cleaned using wet separation processes such as froth flotation. Dewatering of clean coal slurry is essential for marketing the product and reducing the transportation cost. Vacuum filtration is one of the most widely used processes for fine coal dewatering. However, the filter cake often contains more than 20% moisture demanded by the coal industryThe

D. TAO; J. G. GROPPO; B. K. PAREKHM

2000-01-01

26

Prevention of coal mine drainage formation by well dewatering  

Microsoft Academic Search

Large quantities of ground-water may be encountered in deep coal mines which must be treated to meet water-quality standards before being discharged. Source beds supplying leakage to deep mines may be dewatered during and after mining under favorable hydrogeologic conditions to prevent pollution, thereby minimizing treatment costs and improving working conditions. Requisite hydrologeologic data to determine the feasibility of dewatering

Parizek

1971-01-01

27

USING MECHANICAL THERMAL EXPRESSION (MTE) TO DEWATER SEWAGE SLUDGE  

Microsoft Academic Search

Dewatering of sewage sludge is an important part of proper sludge management practice. It is becoming a challenging issue for water industries as new regulations on sludge disposal are being imposed. In this paper, the application of mechanical thermal expression (MTE) to dewater sewage sludge and the conditioning of sludge by mixing with brown coal prior to MTE are investigated.

K. B. Thapa; S. A. Clayton; A. F. A. Hoadley

28

Pressurized electroosmotic dewatering (PED) of fine coal suspensions  

SciTech Connect

Current dewatering methods for ultra-fine coal suspensions are inadequate and usually require subsequent expensive thermal drying. This unique dewatering method is based on pressurized electroosmosis, the movement of water by an electrical field through a porous medium, under modest pressure, e.g., 110 psi. More ultra-fine coal can be utilized since an effective dewatering process can be realized by combining known filtration techniques with electroosmosis. The dewatering efficiency can be significantly improved, the residual moisture of the cake can be substantially reduced and handling problems can be eliminated. Bench-scale testing is being used to optimize the parameters which influence pressurized electroosmotic dewatering (PED) of ultra-fine coal suspensions. Particle size distribution is being addressed to obtain a maximum density for a given pressure such that pore saturation is maintained allowing electroosmosis to be effective for a longer period. The parameters under investigation which influence the dewatering rate include pressure (10 to 110 psi), voltage (10 to 50 VDC), current (0.5 to 2 A) and zeta potential (-10 to -75 mV). The zeta potential of the coal suspensions is being controlled using chemical additions of potential-determining ions, polyelectrolytes and surfactants. These parameters are being optimized in respect to dewatering rate, expended energy per unit of water removed and electrochemical effects. 10 refs., 7 figs.

Heath, L.W.; Demirel, T.

1985-01-01

29

Disposable sludge dewatering container and method  

DOEpatents

This invention is comprised of a device and method for preparing sludge for disposal comprising a box with a thin layer of gravel on the bottom and a thin layer of sand on the gravel layer, an array of perforated piping deployed throughout the gravel layer, and a sump in the gravel layer below the perforated piping array. Standpipes connect the array and sump to an external ion exchanger/fine particulate filter and a pump. Sludge is deposited on the sand layer and dewatered using a pump connected to the piping array, topping up with more sludge as the aqueous component of the sludge is extracted. When the box is full and the free standing water content of the sludge is acceptable, the standpipes are cut and sealed and the lid secured to the box.

Cole, C.M.

1990-12-27

30

Dewatering studies of fine clean coal  

SciTech Connect

The main objective of the present research program is to study and understand dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effect of metal ions and surfactant to lower the moisture of clean coal using conventional vacuum dewatering technique. During this contract period adsorption of di-, tri-, and tetra-valent metal ions, and octadecylamine onto the clean coal was studied. The adsorption of divalent copper ions provided three charge reversal points (or zero-point-of-charges) for the clean coal. The lowest amount of moisture in the filter cake was obtained near the two charge reversal points of the copper-coal system. For the tri-valent aluminum ions and tetra-valent titanium ions one charge reversal, at pH 8.0 and pH 5.0 was observed, respectively. The moisture in the filter cake was lowest near the zero point of charge (ZPC) or both the metal ions. Adsorption of octadecylamine onto the coal provided one ZPC at pH {approximately}7. 0. However, moisture content of the filter cake was not significantly lowered at this pH Morphology of the filter cake obtained without the addition of metal ions or surfactant, showed segregation of large particle at the bottom of filter cake. Efforts are in progress to determine effect of combining metal ions and various (nonionic and anionic) surfactant on filtration, and utilizing a better approach to study the in-situ morphology of the filter cake. 13 figs.

Parekh, B.K. (Kentucky Univ., Lexington, KY (USA). Center for Applied Energy Research)

1991-01-01

31

Dewatering of Mineral Waste Using the Flocculant Polyethylene Oxide.  

National Technical Information Service (NTIS)

The bulletin summarizes the results of Bureau of Mines investigations of a technique for dewatering clay waste that consists of flocculation with polyethylene oxide (PEO) followed by screening of the resulting flocs. Results of laboratory tests and small-...

B. J. Scheiner A. G. Smelley D. A. Stanley

1985-01-01

32

Mechanical Dewatering of Alum Solids and Acidified Solids: An Evaluation  

Microsoft Academic Search

The city of Durham, N.C., performed full-scale testing of alum recovery from alum sludge generated in a 22-mgd water treatment plant. Purposes of the tests were to determine the technical feasibility of mechanical dewatering of acidified alum solids and to develop design data. Three mechanical dewatering devices—a belt press, a centrifuge, and a diaphragm filter press—were screened in bench-scale tests.

Mark M. Bishop; David A. Cornwell; A. T. Rolan; Thomas L. Bailey

1991-01-01

33

Mechanical properties of dewatered sewage sludge.  

PubMed

The mechanical properties of dewatered, anaerobically digested sewage sludge were determined from soil laboratory tests. The sludge material is largely composed of organic clay sized-particles, a sizable fraction of which is in an active state of biological digestion which can continue over many years under field conditions. Moderately digested sludge material was found to have a typical specific gravity of solids value of 1.55, and loss on ignition (LOI) value of 70% dry mass. Strongly digested sludge, produced by digesting the liquid sludge further at 35 degrees C in the laboratory, was found to have a lower LOI value of 55% dry mass, and a higher specific gravity of solids value of about 1.72. The maximum dry density of 0.56 tonne/m3 for the dried sludge material was produced using standard Proctor compaction at roughly 85% moisture content (54% solids content). Air-dried, compacted sludge material was tested in quick-undrained triaxial compression and vane shear. Undrained shear strength-moisture content plots are presented. Shear strength values measured in triaxial compression and vane shear were consistent. The effective angle of shearing resistance (phi') was determined from consolidated-undrained, triaxial compression tests on pasteurized, normally consolidated samples of the sludge material. The mechanical properties of the sludge material changed with the level of sludge digestion. The phi' value increased from 32 degrees for moderately digested sludge, to 37 degrees for strongly digested sludge. The effective cohesion of the sludge material remained zero throughout. The shrinkage, swelling and adhesion properties of the sludge material were also studied. Significant shrinkage occurred as the compacted material dried. The sludge material lost its adhesion below about 95% moisture content (51% solids content). Re-hydration of the dry material caused the bulk volume to double. PMID:15681178

O'Kelly, Brendan C

2005-01-01

34

Improving thermal dewatering characteristics of mechanically dewatered sludge: response surface analysis of combined lime-heat treatment.  

PubMed

In this study, disintegration of dewatered sludge (dry solids content [DS%] = 23 +/- 2) was studied to assess the possibility of enhancing the overall performance of a thermal dewatering processes. Powdered lime was used as an alkaline disintegrator. The combined effects of drying temperature, powdered lime dosage, and organic content on the thermal drying rate of dewatered sludge were investigated in a full-scale wastewater treatment plant. Effects of selected design parameters on the sludge drying rate were modeled using a response surface method. In addition, the possible interaction between lost on ignition and total organic carbon parameters also was investigated statistically. Specific resistance to filtration and free water contents of raw and disintegrated mixed sludge (DS% = 1.0 to 1.8) samples were compared statistically. The obtained results indicated that all of the selected design parameters have a significant effect on thermal dewatering characteristics, and the alkaline disintegration technique could remarkably improve thermal evaporation rate of dewatered sludge. These results are important because they could help to establish a sustainable sludge management model, which is critical in reducing environmental health risks. PMID:21657191

Tunçal, Tolga

2011-05-01

35

Dewatering of the Jenkins open pit uranium mine  

SciTech Connect

Mining of low grade uranium sandstones in the Jenkins open pit mine in the Shirley Basin, Wyoming was troubled by slope failures and wet conditions in the pit. Since the mine was expanding toward a river, the possibility of drainage from this river into the mine raised serious concern during the mine planning. A baseline hydrogeologic study was performed and dewatering measures were designed with the help of a numerical mathematical model. A combination of dewatering wells installed from the surface around the perimeter of the pit and horizontal drains in areas of high slope failure potential substantially improved the mining conditions and slope stability. This procedure consequently led to the successful ore recovery from the highly saturated sandstone strata. The development of drawdown during the dewatering of two separated aquifers in the overburden was close to that predicted by the model.

Straskraba, V.; Kissinger, L.E.

1984-12-01

36

Dewatering of microalgal cultures: A major bottleneck to algae-based fuels  

Microsoft Academic Search

Microalgae dewatering is a major obstruction to industrial-scale processing of microalgae for biofuel production. The dilute nature of harvested microalgal cultures creates a huge operational cost during dewatering, thereby, rendering algae-based fuels less economically attractive. Currently there is no superior method of dewatering microalgae. A technique that may result in a greater algal biomass may have drawbacks such as a

Nyomi Uduman; Ying Qi; Michael K. Danquah; Gareth M. Forde; Andrew Hoadley

2010-01-01

37

Sludge dewatering: Sewage treatment. (Latest citations from the COMPENDEX database). Published Search  

SciTech Connect

The bibliography contains citations concerning dewatering techniques and equipment for sewage treatment. Sewage sludge dewatering design, development, and evaluation are discussed. Essential types of dewatering equipment such as centrifuges, filters, presses, and drums are considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-05-01

38

Sludge dewatering: Sewage treatment. (Latest citations from the EI Compendex*plus database). Published Search  

SciTech Connect

The bibliography contains citations concerning dewatering techniques and equipment for sewage treatment. Sewage sludge dewatering design, development, and evaluation are discussed. Essential types of dewatering equipment such as centrifuges, filters, presses, and drums are considered. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-01-01

39

Reactivation and growth of non-culturable indicator bacteria in anaerobically digested biosolids after centrifuge dewatering  

Microsoft Academic Search

Recent literature has reported that high concentrations of indicator bacteria such as fecal coliforms (FCs) were measured in anaerobically digested sludges immediately after dewatering even though low concentrations were measured prior to dewatering. This research hypothesized that the indicator bacteria can enter a non-culturable state during digestion, and are reactivated during centrifuge dewatering. Reactivation is defined as restoration of culturability.

Matthew J. Higgins; Yen-Chih Chen; Sudhir N. Murthy; Donald Hendrickson; Joseph Farrel; Perry Schafer

2007-01-01

40

Processing of sewage sludge: Dependence of sludge dewatering efficiency on amount of flocculant  

Microsoft Academic Search

Paper presents results of experimental dewatering of stabilized sludge analysis and study. The experiments were carried out at a small waste water treatment plant (15,000 population equivalent). Experiment focused on impact of consumption of flocculant and centrifuge load on quality of dewatered sludge and centrate. Dry solids in dewatered sludge and content of undissolved particles in the centrate were observed

Jaroslav Borá?; Lucie Houdková; Thomas Elsäßer

2010-01-01

41

DEWATERING OF PHOSPHORUS EXTRACTED FROM LIQUID SWINE WASTE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phosphorus (P) recovery from liquid swine manure is an attractive technology when on-farm application of liquid swine manure is not an option. We developed a technology that recovers this P, but its high moisture content makes transportation difficult. In this work, we investigated dewatering proced...

42

Basin dewatering near salt domes and formation of brine plumes  

Microsoft Academic Search

The USGS code SUTRA was used to model the formation of brine plumes around a generic salt dome by basin dewatering along the flanks of the dome, and also to study the gravitational instability of a brine plume initially perched above a dome, in the absence of an externally impressed driving force for upwelling. It is shown that a brine

Vishnu Ranganathan

1992-01-01

43

Dewatering of Coal Fines with Vacuum Belt Filter Installations.  

National Technical Information Service (NTIS)

It is reported about operation results of the primary use of a vacuum belt filter in coal mining to dewater flotation concentrate. A high availability, accessibility and good servicing were achieved. The belt filter can be adapted to varying conditions of...

1982-01-01

44

Assessing dewatering performance of drinking water treatment sludges  

Microsoft Academic Search

A comparison of the dewaterability of a range of water treatment plant sludges has been completed through computation of dewatering performance indicators for a diaphragm filter press. Real parameter data, obtained from the characterisation of alum and ferric sludges, generated under precisely controlled conditions, was used for input to a phenomenological model. Comparisons of dewaterability based on throughput curves largely

David I. Verrelli; David R. Dixon; Peter J. Scales

2010-01-01

45

Improved Dewatering of Coal by Steam Pressure Filtration  

Microsoft Academic Search

The use of steam as an over-pressure forming gas phase has the advantage of a combined mechanical and thermal dewatering. Steam pressure filtration can provide an economical and effective technique, whereas conventional solid-liquid separation processes do not lead to a marketable residual moisture content of the product. A condensation front is built at the cold layers of the filter cake,

S. GERL; W. STAHL

1996-01-01

46

30. VIEW SOUTHEAST ON SHELTON SIDE OF DAM DURING DEWATERING. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. VIEW SOUTHEAST ON SHELTON SIDE OF DAM DURING DEWATERING. CORNER OF SHELTON LOCKS AND MITRE GATES AT RIGHT. - Ousatonic Water Power Company, Dam & Canals, CT Routes 34 & 108, 1 mile North of Derby-Shelton Bridge, Derby, New Haven County, CT

47

28. VIEW NORTH TOWARD DERBY DURING DEWATERING. DAM IN CENTER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. VIEW NORTH TOWARD DERBY DURING DEWATERING. DAM IN CENTER OF PICTURE WITH SHELTON GATEHOUSE ON LEFT AND DERBY GATEHOUSE ON RIGHT. - Ousatonic Water Power Company, Dam & Canals, CT Routes 34 & 108, 1 mile North of Derby-Shelton Bridge, Derby, New Haven County, CT

48

Characteristics and mechanisms of phosphate adsorption on dewatered alum sludge  

Microsoft Academic Search

The adsorption characteristics of phosphate adsorption on the dewatered alum sludge were identified as a function of pH and ion strengths in solution. In addition, adsorption mechanisms were investigated by conducting batch tests on both the hydrolysis and P-adsorption process of the alum sludge, and making a comparative analysis to gain newer insights into understanding the adsorption process. Results show

Y. Yang; Y. Q. Zhao; A. O. Babatunde; L. Wang; Y. X. Ren; Y. Han

2006-01-01

49

15. VIEW NORTHNORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW NORTH-NORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED AREAS AT BACK OF TUNNEL IS A HOUSING FOR CONDUCTING PERFORMANCE TESTING ON AIRCRAFT MODELS IN A VORTEX. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

50

Development of an Advanced Fine Coal Suspension Dewatering Process  

SciTech Connect

With the advancement in fine coal cleaning technology, recovery of fine coal (minus 28 mesh) has become an attractive route for the U.S. coal industry. The clean coal recovered using the advanced flotation technology i.e. column flotation, contains on average 20% solids and 80% water, with an average particle size of 35 microns. Fine coal slurry is usually dewatered using a vacuum dewatering technique, providing a material with about 25 to 30 percent moisture. The process developed in this project will improve dewatering of fine (0.6mm) coal slurry to less than 20 percent moisture. Thus, thermal drying of dewatered wet coal will be eliminated. This will provide significant energy savings for the coal industry along with some environmental benefits. A 1% increase in recovery of coal and producing a filter cake material of less than 20 % moisture will amount to energy savings of 1900 trillion Btu/yr/unit. In terms of the amount of coal it will be about 0.8% of the total coal being used in the USA for electric power generation. It is difficult to dewater the fine clean coal slurry to about 20% moisture level using the conventional dewatering techniques. The finer the particle, the larger the surface area and thus, it retains large amounts of moisture on the surface. The coal industry has shown some reluctance in using the advanced coal recovery techniques, because of unavailability of an economical dewatering technique which can provide a product containing less than 20% moisture. The U.S.DOE and Industry has identified the dewatering of coal fines as a high priority problem. The goal of the proposed program is to develop and evaluate a novel two stage dewatering process developed at the University of Kentucky, which involves utilization of two forces, namely, vacuum and pressure for dewatering of fine coal slurries. It has been observed that a fine coal filter cake formed under vacuum has a porous structure with water trapped in the capillaries. When this porous cake is subjected to pressure for a short time, the free water present is released from the filter cake. Laboratory studies have shown that depending on the coal type a filter cake containing about 15% moisture could be obtained using the two-stage filtration technique. It was also noted that applying intermittent breaks in vacuum force during cake formation, which disturbed the cake structure, helped in removing moisture from the filter cakes. In this project a novel approach of cleaning coal using column flotation was also developed. With this approach the feed capacity of the column is increased significantly, and the column was also able to recover coarser size coal which usually gets lost in the process. The outcome of the research benefits the coal industry, utility industry, and indirectly the general public. The benefits can be counted in terms of clean energy, cleaner environment, and lower cost power.

B. K. Parekh; D. P. Patil

2008-04-30

51

Development of an Ultrafine Coal Dewatering Technology and an Integrated Flotation-Dewatering System for Coal Preparation Plants  

Microsoft Academic Search

The project proposal was approved for only the phase I period. The goal for this Phase I project was to develop an industrial model that can perform continuous and efficient dewatering of fine coal slurries of the previous flotation process to fine coal cake of 15% water content from 50-70%. The feasibility of this model should be demonstrated experimentally using

Wu Zhang; David Yang; Amar Amarnath; Iftikhar Huq; Scott OBrien; Jim Williams

2006-01-01

52

Dewatering of ultrafine coal: Final report, August 1984-December 1986  

SciTech Connect

The surfactant, Aerosol-OT, was used to wash distilled water cakes. In previous studies, cakes were washed with Triton X-114. The dewatering performance and influence on cake structure of the two reagents are compared. Also, filter cakes were analyzed using an image analysis system and micrographic analysis of coal particles was initiated. In the area of theoretical modelling, the concept of bond-flow correlation greatly improved the network model predicting the experimental desaturation curves. Predicted results for treated cakes suggested that the effect of the presence of surface-active agents was adequately accounted for. The effects of the various operating conditions on the filtration/dewatering characteristics of the 10 ..mu..m coal particles were assessed and comparisons with the -32 mesh coal were made as to its trends in response to changes in the operating conditions. 20 refs., 75 figs., 17 tabs.

Chiang, Shiao-Hung; Klinzing, G.E.; Morsi, B.I.; Tierney, J.W.; Badgujar, M.; Binkley, T.; Cheng, Yisun; Huang, Suxuan; Qamar, I.; Venkatadri, R.

1986-12-01

53

Evaluation of hyperbaric filtration for fine coal dewatering. Final report  

SciTech Connect

The main objectives of the project were to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20% moisture. The program consisted of three phases, namely Phase 1 -- Model Development, Phase 2 -- Laboratory Studies, Phase 3 -- Pilot Plant Testing. The Pennsylvania State University led efforts in Phase 1, the University of Kentucky in Phase 2, and CONSOL Inc. in Phase 3 of the program. All three organizations were involved in all the three phases of the program. The Pennsylvania State University developed a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky conducted experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase 1 and 2 were tested in two of the CONSOL Inc. coal preparation plants using an Andritz Ruthner portable hyperbaric filtration unit.

Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL Inc. (United States)

1996-08-15

54

Evaluation of hyperbaric filtration for fine coal dewatering  

SciTech Connect

Most of the coal presently used by the utility industry is cleaned at preparation plants employing wet processes. Water, while being the mainstay of coal washing, is also one of the least desirable components in the final product. Coarse coal (+3/4 inch) is easily dewatered to a 3--4 percent moisture level using conventional vibrating screens and centrifuges. However, the main problem of excess product moisture occurs in fine (minus 28 mesh) coal and refuse. Even though fines may constitute only about 20 percent of a contemporary cleaning plant feed, they account for two-thirds of the product surface moisture. This high surface moisture offsets many of the benefits of coal cleaning, and can easily undercut the ongoing programs on recovery of fine clean coal from refuse as well as producing an ultra-fine super clean coal fuel. Currently, most of the coal preparation plants utilize vacuum disk type technology for dewatering of the fine coal, providing dewatered product containing about 25 percent moisture. The coal industry would prefer to have a product moisture in the range of 10 to 15 percent, thereby avoiding thermal drying of coal. Hyperbaric filtration. has shown potential in lowering moisture in fine coal to about 20 percent level. This project will develop fundamental information on particle-liquid interaction during hyperbaric filtration and apply the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.

Parekh, B.K. (Kentucky Univ., Lexington, KY (United States)); Hogg, R. (Pennsylvania State Univ., University Park, PA (United States)); Fonseca, A. (CONSOL, Inc., Pittsburgh, PA (United States))

1992-01-01

55

Synergism in polyethylene oxide dewatering of phosphatic clay waste  

SciTech Connect

As part of research conducted in its mission to effect pollution abatement, the Bureau of Mines, US Department of the Interior, is developing a dewatering technique that allows for disposal of phosphatic clay wastes, for reuse of water now lost with clays, and for reclamation of mined land. The technique utilizes a high-molecular-weight nonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater phosphatic clay wastes. A synergistic flocculation study was made to determine whether a portion of PEO could be replaced by other reagents. Several groups of reagents were tested: (1) those that increased the zeta potential of the phosphatic clay wastes; (2) those capable of hydrogen bonding; and (3) those which flocculated the phosphatic clay waste. Reduction in PEO consumption occurred only with addition of those reagents able to flocculate the slime. The use of natural guar gums resulted in a lower PEO requirement and also yielded a dewatered product of higher solids content, 43 to 45%, versus 33 to 35% obtained with PEO alone.

Smelley, A.G.; Scheiner, B.J.

1980-01-01

56

Dewatering model for optimal operation of sludge treatment wetlands.  

PubMed

Sludge treatment wetlands (STW) are used as a dewatering technology in some European countries since the 80's. Although the efficiency of this technology in terms of sludge dewatering and mineralisation is well known, design and operation parameters are yet to be standardised. The aim of this study is to develop a mathematical model capable of predicting the water loss with time, in order to optimise the feeding frequency enhancing sludge dewatering and expanding the lifespan of the system. The proposed model is validated with experimental data from one pilot and two full-scale STW. The scenarios considered indicate that the optimum feeding frequency decreases with the sludge layer height. In this way, systems with a sludge layer of 20 cm, 40 cm and 80 cm (corresponding to 2, 4 and 8 years of operation), should be fed every 2.5, 10 and 30-40 days, respectively. On the other hand, evapotranspiration (ET) has no effect on the feeding frequency, although it does increase the sludge dryness from 25% to 45% (for ET of 2.5 and 14.5 mm/d in the case of 20 cm of sludge height). According to the model output, the sludge loading rate is determined as a function of evapotranspiration, feeding frequency and sludge height. PMID:22118909

Uggetti, Enrica; Argilaga, Albert; Ferrer, Ivet; García, Joan

2011-11-06

57

Dewatering: Coal and mineral processing. (Latest citations from the COMPENDEX database). Published Search  

SciTech Connect

The bibliography contains citations concerning the technology of dewatering. Included is coverage of techniques, processes, and evaluations applied to coal processing, coal slurry preparation, ash treatments, and processing of other mineral ores. Mechanical devices, heating devices, filtering techniques, air drying, the use of surfactants and flocculants, and design techniques in dewatering systems are discussed. Dewatering of peats, sewage sludges, and industrial sludges are referenced in related bibliographies. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-05-01

58

Dewatering studies of fine clean coal. Annual technical report, September 1, 1990--August 31, 1991  

SciTech Connect

The main objective of the present research program is to study and understand dewatering characteristics of ultrafine clean coal obtained using the advanced column flotation technique from the Kerr-McGee`s Galatia preparation plant fine coal waste stream. It is also the objective of the research program to utilize the basic study results, i.e., surface chemical, particle shape particle size distribution, etc., in developing a cost-effective dewatering method. The ultimate objective is to develop process criteria to obtain a dewatered clean coal product containing less that 20 percent moisture, using the conventional vacuum dewatering equipment. (VC)

Parekh, B.K.

1991-12-31

59

Electroosmotically enhanced dewatering/deliquoring of fine-particle coal. Final report, January 1, 1989-August 31, 1990.  

National Technical Information Service (NTIS)

This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coals are inadequate and generally require subsequent thermal drying. The first year of this...

S. Sami P. K. Davis J. G. Smith

1990-01-01

60

Development and Testing of a Novel Mechanical Device for Dewatering Peat. Quarterly Technical Progress Report, January 1-March 31, 1985.  

National Technical Information Service (NTIS)

The concept of an Internal Rotary Compression (IRC) press system was suggested by Anderson Metal Industries, Inc. (AMI). The IRC system has the following apparent advantages over current mechanical dewatering devices: (1) improved peat dewatering, achieva...

1985-01-01

61

Development and Testing of a Novel Mechanical Device for Dewatering Peat. Topical Report, September 22, 1983-March 23, 1984.  

National Technical Information Service (NTIS)

The Internal Rotary Compression (IRC) system concept to be tested in this program for the mechanical dewatering of peat is suggested by Anderson Metals Industries, Inc. This system has the following advantages over current mechanical dewatering devices: (...

1984-01-01

62

Modeling of hyperbaric filtration and dewatering of coal  

NASA Astrophysics Data System (ADS)

Generalized models have been developed for continuous hyperbaric filtration to evaluate cake formation, filter capacity/filter area, cake dewatering, air consumption and residual cake saturation/residual cake moisture. Emphasis has been placed on cake structure as being a major controlling factor in fine coal dewatering by filtration. The effects of cake structure, as defined by the distributions of pore size and shape, have been reviewed. A simple model relating cake structure to feed particle characteristics is presented and applied to a practical case of fine coal dewatering. A binary packing model has been proposed to explain the existence of compressibility in non-compressible cakes. This model proposes an inner open-structure in the main cake, with the inner layer being compressible. The variation in the inner cake porosity with applied pressure has been used to explain the change in specific cake resistance and filter capacity (solids cake throughput). Process simulations have been conducted for a single stage and a two stage process, wherein the original feed has been split into a coarse fraction and a fine fraction (and then each fraction processed separately). The process simulations for a two stage process show a lot of promise as this leads to a lowering of the required filter area and the residual cake moisture. The required filter area increases, while the residual cake moisture decreases as the cut size for the two stage process is increased. However, the advantages of a two stage process are adversely affected by an inefficient separation process, which leads to an increased filter area and a higher residual cake moisture and the two stage process approaches a single stage process.

Ranjan, Sushil

63

Dewatering Active Underground Coal Mines. Technical Aspects and Cost-Effectiveness.  

National Technical Information Service (NTIS)

This study evaluated the cost-effectiveness of dewatering an active underground coal mine as an alternative or supplement to treating acid mine drainage. A dewatering program was formulated and base-line data collection was performed in conjunction with e...

1979-01-01

64

EVALUATION OF FULL-SCALE SUGAR BEET TRANSPORT WATER SOLIDS DEWATERING SYSTEM  

EPA Science Inventory

The objectives of this study were to evaluate a full-scale vacuum filtration system for dewatering solids removed from the transport water in an operating beet sugar plant in terms of operational reliability and efficiency, economics, and ultimate disposal of the dewatered solids...

65

EVALUATION OF DEWATERING DEVICES FOR PRODUCING HIGH-SOLIDS SLUDGE CAKE  

EPA Science Inventory

Pilot-plant dewatering tests were made to establish design and operating parameters for dewatering municipal wastewater sludges on recessed plate filter presses (both diaphragm and fixed volume types), continuous belt presses, and retrofit units for a vacuum filter. Results from ...

66

Sludge dewatering: Sewage and industrial wastes. (Latest citations from Pollution Abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning techniques and equipment used in dewatering waste products. Included are techniques for sewage waste as well as industrial, mining, petroleum, and municipal waste sludge. Dewatering processes, device design, and performance evaluations are considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-07-01

67

Sludge dewatering: Sewage and industrial wastes. (Latest citations from pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning sewage sludge dewatering techniques and equipment in industrial and municipal waste treatment systems. Topics include dewatering processes and control, activated sludge systems, fluidized bed systems, biological treatment, heavy metal recovery, and economic aspects. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1995-11-01

68

Sludge dewatering: Sewage and industrial wastes. (Latest citations from Pollution Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning techniques and equipment used in dewatering waste products. Included are techniques for sewage waste as well as industrial, mining, petroleum, and municipal waste sludge. Dewatering processes, device design, and performance evaluations are considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-11-01

69

Kinetic Laws Governing Vacuum Dewatering of Thermally Unstable Materials in the Foamed State  

Microsoft Academic Search

Sublimation drying in a vacuum is traditionally used to achieve high quality of dewatered materials. The technico-economic indicators of this method are low, however, due to high energy outlays, prolonged duration of the process, and complexity of the equipment employed [1]. An alternative method of dewatering thermally unstable materials is their drying in a vacuum under a pressure slightly above

G. V. Semenov; A. N. Red'kin

2001-01-01

70

Dewatering behaviour of water treatment sludges associated with contaminated site remediation in Antarctica  

Microsoft Academic Search

Sludge reduction and dewatering is an important aspect of water and waste water treatment. This is especially true in the case of Australia's Antarctic contaminated site remediation program, where the reduction in volume of wastes to be returned to Australia can lead to significant transport and handling cost savings. The dewatering characterisation of water treatment sludges from an Antarctic contaminated

Kathy A. Northcott; Ian Snape; Peter J. Scales; Geoff W. Stevens

2005-01-01

71

Effects of polymer dosage on alum sludge dewatering characteristics and physical properties  

Microsoft Academic Search

The proper use of polymers as conditioners is a critical aspect of dewatering processes. In this study, we investigate their physical properties, i.e. size, density and fractal dimension and correlate them with their dewatering characteristics (bound water content, CST and SRF) on alum sludge with cationic polymer conditioning. Using CST measurement to determine the optimum polymer dose may lead to

Chih Chao Wu; Chihpin Huang; D. J. Lee

1997-01-01

72

Dehydration properties of different flocculants in the processes of sludge dewatering  

Microsoft Academic Search

Sludge dewatering is a crucial factor in the reduction of sludge volume and transportation costs. Different flocculants were applied in the sludge dewatering experiments and their dehydration effects were discussed. Several parameters of the sludge flocculation were presented, such as water content, turbidity, transmittance and ? potential. The results showed that the composite flocculation could promote respective flocculation performance and

Wu YanI; Li Yan; Hu Baoan; Zheng Wei; Ran Wenjun

2010-01-01

73

ADAPTIVE PRE-EMPTIVE CONTROL OF VACUUM DEWATERING IN PAPER MANUFACTURING 1  

Microsoft Academic Search

Paper manufacturing involves the sequential removal of water from pulp by means of gravity, vacuum dewatering, mechanical pressing and thermal drying. This research proposes a new control topology for moisture content using surrogate measurements to infer in-process moisture content, and the pressure settings in the vacuum dewatering section as actuators. The new topology has the potential to overcome the performance,

Petar Bjegovic; Perry Y. Li

74

Challenges in Dewatering of Indian Medium Coking Coals: Case Studies with Chemical Reagents  

Microsoft Academic Search

At the West Bokaro Washery of Tata Steel, India, the coarse coal is dewatered in a vibrating basket centrifuge and fine clean coal is dewatered in a screen bowl centrifuge. Due to the higher amount of fine fraction (0.038 mm) treated in the flotation circuit of the washery (about 9% of ROM), the moisture content of the clean coal fines is

P. K. Banerjee; A. Das; A. Kr. Gupta; A. Prasad; A. K. Misra; A. M. Misra

2007-01-01

75

Mechanism of fine-coal dewatering by silicone additives. Final report  

Microsoft Academic Search

The objectives of this study were to explore the utility of silicones in the enhancement of coal dewatering and in particular to elucidate the mechanism of the effect. Both basic surface studies and practical dewatering assessments were used to address the problem. Several techniques were employed including surface tension, contact angle, and zeta potential measurements, ESCA (Electron Spectroscopy for Chemical

1984-01-01

76

New coal dewatering technology turns sludge to powder  

SciTech Connect

Virginian Tech's College of Engineering's Roe-Hoan Yoon and his group have developed a hyperbaric centrifuge that can dewater coal as fine as talcum powder. Such coal fines presently must be discarded by even the most advanced coal cleaning plants because of their high moisture content. The new technology can be used with the Microcel technology to remove ash, to re-mine the fine coal discarded to impoundments and to help minimize waste generation. Virginia Tech has received $1 million in funding from the US Department of State to also help the Indian coal industry produce a cleaner product. 1 photo.

NONE

2009-03-15

77

Development of an Ultra-fine Coal Dewatering Technology and an Integrated Flotation-Dewatering System for Coal Preparation Plants  

SciTech Connect

The project proposal was approved for only the phase I period. The goal for this Phase I project was to develop an industrial model that can perform continuous and efficient dewatering of fine coal slurries of the previous flotation process to fine coal cake of {approx}15% water content from 50-70%. The feasibility of this model should be demonstrated experimentally using a lab scale setup. The Phase I project was originally for one year, from May 2005 to May 2006. With DOE approval, the project was extended to Dec. 2006 without additional cost from DOE to accomplish the work. Water has been used in mining for a number of purposes such as a carrier, washing liquid, dust-catching media, fire-retardation media, temperature-control media, and solvent. When coal is cleaned in wet-processing circuits, waste streams containing water, fine coal, and noncombustible particles (ash-forming minerals) are produced. In many coal preparation plants, the fine waste stream is fed into a series of selection processes where fine coal particles are recovered from the mixture to form diluted coal fine slurries. A dewatering process is then needed to reduce the water content to about 15%-20% so that the product is marketable. However, in the dewatering process currently used in coal preparation plants, coal fines smaller than 45 micrometers are lost, and in many other plants, coal fines up to 100 micrometers are also wasted. These not-recovered coal fines are mixed with water and mineral particles of the similar particle size range and discharged to impoundment. The wasted water from coal preparation plants containing unrecoverable coal fine and mineral particles are called tailings. With time the amount of wastewater accumulates occupying vast land space while it appears as threat to the environment. This project developed a special extruder and demonstrated its application in solid-liquid separation of coal slurry, tailings containing coal fines mostly less than 50 micron. The extruder is special because all of its auger surface and the internal barrier surface are covered with the membranes allowing water to drain and solid particles retained. It is believed that there are four mechanisms working together in the dewatering process. They are hydrophilic diffusion flow, pressure flow, agitation and air purging. Hydrophilic diffusion flow is effective with hydrophilic membrane. Pressure flow is due to the difference of hydraulic pressure between the two sides of the membrane. Agitation is provided by the rotation of the auger. Purging is achieved with the air blow from the near bottom of the extruder, which is in vertical direction.

Wu Zhang; David Yang; Amar Amarnath; Iftikhar Huq; Scott O'Brien; Jim Williams

2006-12-22

78

Enhanced dewatering of polyelectrolyte nanocomposites by hydrophobic polyelectrolytes.  

PubMed

We demonstrate that increasing the hydrophobic environment around the charge center of a polyelectrolyte (PE) not only decreases the water content of an adsorbed PE layer but can even dewater up to ~50% of an initially hydrated substrate. The results of this work are expected to yield new stratagies to dewater PE systems and have potential applications in mineral recovery, paper manufacturing, and biomedical materials. Adsorption of a series of cationically derivatized dextran polyelectrolytes onto sulfated nanocrystalline cellulose (SNC) has been studied using quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR). Synthesized samples of (N,N-dimethylamino)ethyldextran (DMAE-Dex), (N,N-diethylamino)ethyldextran (DEAE-Dex), and (N,N-diisopropylamino)ethyldextran (DIAE-Dex) had degrees of substitution (DS) ranging from 0.05 to 0.82. DMAE-Dex, DEAE-Dex, and DIAE-Dex all showed decreasing adsorption onto SNC and decreasing water content of the adsorbed film with increasing DS. Additionally, DEAE-Dex and DIAE-Dex films adsorbed onto SNC contained less water than DMAE-Dex films with the same DS. Interestingly, QCM-D results for high DS DIAE-Dex adsorbed onto SNC revealed mass loss, whereas SPR results clearly showed DIAE-Dex adsorbed. These observations were consistent with dehydration of the SNC substrate. This study indicates that the water content of the substrate could be tailored by controlling the DS and hydrophobic character of the adsorbed polyelectrolytes. PMID:22667816

Kittle, Joshua D; Wondraczek, Holger; Wang, Chao; Jiang, Feng; Roman, Maren; Heinze, Thomas; Esker, Alan R

2012-07-23

79

Genesis of dewatering structures and its implications for melt-out till identification  

NASA Astrophysics Data System (ADS)

Dewatering structures are a common feature used to identify melt-out till, and the lack of such structures in till could preclude deposition by melt-out. To assess the conditions under which melt-out till can be deposited without forming dewatering structures, I use geotechnical data and a quasi-two-dimensional model of geothermal melt-out. Critical discharge determined from geotechnical data suggests that low-hydraulic-conductivity till can transport up to 1.3 m3 water a-1m-2 without forming dewatering structures,which is two or three orders of magnitude greater than the volume of meltwater produced at the base of glaciers. The model indicates that debris content of the ice and the ability of the till to drain govern effective pressure during melt-out. If the drainage system is poorly developed or the till comes from debris-poor ice, effective pressure is below zero, the condition under which dewatering structures could form. However, till from relatively debris-rich ice (>40% debris) with a well-developed drainage system (channels every 10 m) can dewater without forming dewatering structures. This suggests that the lack of dewatering structures in till does not necessarily imply deposition by lodgement or deforming bed.

Carlson, E. Anders

80

POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy's program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 45 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 ? March 31, 1998.

B. K. Karekh; D. Tao; J. G. Groppo

1998-08-28

81

Effect of brief navigation-related dewaterings on fish eggs and larvae  

USGS Publications Warehouse

Short-term dewatering of nearshore spawning areas often occurs during passage of commercial tows in the upper Mississippi River as well as in other navigated river systems. This phenomenon was examined experimentally to identify potential effects on survival of fish eggs and larvae. Early life stages of walleyes (Stizostedion vitreum vitreum ) and northern pike (Esox lucius ) were dewatered 2 min in laboratory studies at intervals of either 1, 3, 6, or 12 h from just after fertilization to 10-14 d posthatch. Dewatering did not cause mortality of eggs, but significant mortality of larvae of both species occurred at dewatering frequencies of 1 or 3 h. Therefore, significant mortality first was observed at a frequency equivalent to a mean passage of eight tows per day.

Holland, L. E.

1987-01-01

82

Large-Scale Dewatering of Phosphatic Clay Waste from Northern Florida.  

National Technical Information Service (NTIS)

The Bureau of Mines is testing a dewatering technique for phosphatic clay waste that will recover a portion of the water lost using conventional waste disposal methods and produce solids suitable for land reclamation. The technique utilizes a flocculant, ...

A. G. Smelley B. J. Scheiner

1985-01-01

83

Evaluation of geotextile filtration applying coagulant and flocculant amendments for aquaculture biosolids dewatering and phosphorus removal  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wastes contained in the microscreen backwash discharged from intensive recirculating aquaculture systems were removed and dewatered in simple geotextile bag filters. Three chemical coagulation aids, (aluminum sulfate (alum), ferric chloride, and calcium hydroxide (hydrated lime)), were tested in com...

84

Dewatering of Alaska placer effluent using PEO. Report of investigations/1992  

SciTech Connect

The U.S. Bureau of Mines' Tuscaloosa Research Center has been investigating new techniques to improve the dewatering of mineral slurries, to recover water lost in the waste slurry, and to produce dewatered solids suitable for disposal. As part of the investigation, a study was undertaken to investigate the feasibility of dewatering Alaska placer effluent. Based on the laboratory tests, preliminary field tests were conducted on three placer mines in Alaska. At these mines, the water recovered from the placer effluent (250 to 23,000 NTU) exhibited turbidities of 20 to 240 NTU. In the second year of the project, a large-scale dewatering unit was set up at a mine located in the Livengood district. The feed, at flow rates up to 935 gpm, was mixed with dilute PEO solution in a flexible plastic hose with and without static mixers. Feed to the dewatering unit generally ranged between 300 to 26,500 NTU and required PEO dosages of 0.018 to 0.19 lb/1,000 gal to produce water from the screen underflow with turbidities of 20 to 50 NTU. During this period, a small unit was also operated at flow rates of 10 to 25 gpm at seven sites throughout Alaska, with the effluent from four of the sites being dewatered successfully.

Sharma, S.K.; Scheiner, B.J.; Smelley, A.G.

1992-01-01

85

A study of the improvement in dewatering behavior of wastewater sludge through the addition of fly ash  

Microsoft Academic Search

Wastewater sludge is classified as a difficult dewatering material (DDM) due to the high cake specific resistance (CSR). On\\u000a the other hand, fly ash is classified as an easy dewatering material (EDM), which suggests that it might be able to improve\\u000a the dewaterability of wastewater sludge. The water content and cake specific resistance of dewatered sludge without the addition\\u000a of

Jung Eun Lee; Jae Keun Lee; Dong Soo Kim

2010-01-01

86

When the Well Runs Dry: Ecological Consequences of Dewatering Rivers  

NASA Astrophysics Data System (ADS)

Disturbances related to river discharge are thought to define the physical template that structures biological communities and selects for effective life history strategies. Through managing river discharge to support agricultural production in arid and semi-arid landscapes, the timing, frequency, magnitude, and duration of low flow events has been altered. Despite the ubiquitous nature of this management practice, we are currently unable to predict when low flow events impose a disturbance on lotic ecosystems or the spatiotemporal extent of biotic responses. This poster outlines a study that examines gradients in water withdrawal intensity to: 1. Determine if macroinvertebrate communities and environmental variables exhibit threshold or proportional responses to channel dewatering; 2. Characterize spatiotemporal response and recovery patterns of macroinvertebrates to low flow disturbances; 3. Compare life history traits, growth, and developmental rates for invertebrates inhabiting different flow regimes. Preliminary results show macroinvertebrate community structure changing at greater spatial and temporal rates as compared to reference conditions when discharge is reduced by 75 percent or more. The characterization of macroinvertebrate response and recovery patterns to low flow events will help develop innovative strategies that allow agricultural water use, while mitigating structural and functional impacts on lotic systems.

Miller, S. W.

2005-05-01

87

Dewatering sludge originating in water treatment works in reed bed systems.  

PubMed

The dewatering process of the liquid water works sludge was examined in a trial with a series of six trial beds, each 20 m2. These were monitored from April 2008 to June 2010. It is possible to get the vegetation to grow in ferric sludge (approximately 300,000 mg Fe/kg dry solid, pH 7,7). It has not been necessary to use fertilizer. The influence of the loading programs (15-50 kg dry solid/m2/year) was tested with 1-5 days of loading and 35-55 days of rest. It is possible to drain and treat ferric sludge. Generally the dewatering profile is a peak with a maximum over 0.015-0.025 L/s/m2. The times for dewatering of 6-12 m3 are approximately 15 h and over 90% of the load is dewatered in that period. The dry solid (0.16-0.20%) in the sludge has been concentrated approximately 200 times. The dewatering phase results in ferric sludge with 30-40% dry solid which cracks up very quickly. The volume reduction is over 99%. The trend shows that the main volume of reject water has a turbidity level below 5 NTU even in the loading periods. PMID:22097008

Nielsen, S; Cooper, D J

2011-01-01

88

POC-SCALE TESTING OF AN ADVANCED FINE COAL DEWATERING EQUIPMENT/TECHNIQUE  

SciTech Connect

Dewatering of ultra-fine (minus 150 {micro}m) coal slurry to less than 20% moisture is difficult using the conventional dewatering techniques. The main objective of the project was to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions and surfactants in combination for the dewatering of ultra-fine clean-coal slurries using various dewatering techniques on a proof-of-concept (POC) scale of 0.5 to 2 tons per hour. The addition of conventional reagents and the application of coal surface modification technique were evaluated using vacuum filtration, hyperbaric (pressure) filtration, ceramic plate filtration and screen-bowl centrifuge techniques. The laboratory and pilot-scale dewatering studies were conducted using the fine-size, clean-coal slurry produced in the column flotation circuit at the Powell Mountain Coal Company, St. Charles, VA. The pilot-scale studies were conducted at the Mayflower preparation plant in St. Charles, VA. The program consisted of nine tasks, namely, Task 1--Project Work Planning, Task 2--Laboratory Testing, Task 3--Engineering Design, Task 4--Procurement and Fabrication, Task 5--Installation and Shakedown, Task 6--System Operation, Task 7--Process Evaluation, Task 8--Equipment Removal, and Task 9--Reporting.

X.H. Wang; J. Wiseman; D.J. Sung; D. McLean; William Peters; Jim Mullins; John Hugh; G. Evans; Vince Hamilton; Kenneth Robinette; Tim Krim; Michael Fleet

1999-08-01

89

Development of A Continuous Process for Displacement Dewatering  

SciTech Connect

The subject of this contract was to investigate the viability of a new process for dewatering paper called displacement pressing. The term “displacement pressing” was coined in the 1980s by researchers to describe a paper dewatering process where air is blown through a sheet of paper while it is being pressed. It was shown at that time that the combination of air and low pressing force could dramatically increase both sheet bulk and sheet solids which in theory would translate into huge savings in energy and fiber consumption. But there was a catch. Although the research results were dramatic, no one could figure out a commercially viable process to carry out displacement pressing. All research work had been done with batch processes, and there was no obvious way to convert these processes into a continuous process. By the end of the early1990’s no one was researching in this area because no continuous process existed. Recently we proposed a new method to carry out displacement pressing. Our process uses special pressing fabrics and a special 4 roll press that we call a “Beck Cluster Press” or BCP. The BCP provides a pressurized atmosphere that acts on a moving web of paper and fabrics. The special fabrics designed for this process use this atmosphere to press the sheet and at the same time, these special fabrics force air through the sheet to carry out displacement pressing. 1 Because of the complexity and cost of building the first functioning BCP, a simple simulator was built to confirm and study the process. Although results from this simulator were extremely favorable, financial times were hard in the paper industry. We are grateful for the DOE contract that allowed us to continue research that showed the tremendous benefits of displacement pressing. Specifically, accomplishments from the DOE contract are as follows: 1. A narrow (5” wide sheet) lab Beck Cluster Press (BCP) was started up, and made operational. This press accepts hand sheets and displacement presses them at conditions that duplicate commercial conditions for dwell time, and pressure. 2. The lab BCP machine was used to verify simulator results. Results showed the lab BCP gave paper dryness that exceeded simulator results for dryness. 3. Sheet samples were obtained for several paper grades. These samples were pressed conventionally (shoe and roll presses) and with the lab BCP. Results showed significant gains in bulk (5-48%) compared to commercially pressed sheets while producing similar or higher dryness. These results verified the predictions of the earlier research papers. 4. Sheet bulk exceeded the Agenda 2020 goal a 7% increase. This increase in bulk was reported by Agenda 2020 as being worth about 3 billion dollars per year in fiber savings. Potential energy savings due to dryness savings could be worth $1 billion per year. However energy savings and fiber savings are inter-related so while savings are likely in both energy and fiber at the same time, increasing one will cause the other to decrease. 5. Based on the significant results of small-scale BCP trials, a 1m pilot BCP press stand was built to determine scalability of the process. 6. 1m pilot press stand was started up. This machine was shown to hold design pressure. Drive issues however prevented operation at operating speed and pressure during the contact period. Improvements to the drive system since the end of the DOE contract have allowed us to reach operating pressure and speed. 7. The last DOE objective of passing paper through the 1m BCP was not reached due to drive issues and the desire to study and qualify sealing systems. All other original objectives and the added objective (by contract revision) of this ambitious project have been met. 8. Several paper companies have showed interest in helping us commercialize this process. Interest is so high that these companies appear willing to invest in further development.

Dave Beck

2006-10-30

90

Calcium loading during the dewatering of wet biomass in kerosene and catalytic activity for subsequent char gasification  

Microsoft Academic Search

This paper describes a novel approach for upgrading biomass fuels with high water content for gasification, using an oil-slurry dewatering (OSD) process and wet coffee grounds (CG) as a feedstock. The point of novelty is that calcium loading is carried out during the dewatering of wet CG in kerosene. The present work is focused on characterizing the dispersion state of

Yan Zhang; Masami Ashizawa; Shiro Kajitani

2008-01-01

91

Theoretical and experimental aspects of dewatering effects on wastewater sludge induced by high-energy electrons and gamma radiation  

Microsoft Academic Search

$\\\\sp{60}$Co $\\\\gamma$-source and electron beam radiation were investigated as alternative methods for sludge conditioning. Since the efficiency of sludge disinfection, and toxic organic chemical destruction with irradiation is well documented, this study concentrated on theoretical and experimental aspects of sludge dewatering enhancement due to irradiation. The primary parameters used for evaluation of dewatering were: specific resistance of filtration (SRF), bound

Tiezheng Wang

1993-01-01

92

Evaluation of hyperbaric filtration for fine coal dewatering. Seventh quarterly technical progress report, April 1, 1994--June 30, 1994  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. This project is oriented into three phases.

Parekh, B.K.; Hogg, R.; Fonseca, A.

1994-10-01

93

Evaluation of hyperbaric filtration for fine coal dewatering. Third quarterly technical progress report, March 1, 1993--May 31, 1993  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. Progress is described.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL, Inc., Pittsburgh, PA (United States)

1993-09-01

94

Dewatering of petroleum-containing sludges with recovery of the oil component  

SciTech Connect

A process is disclosed for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein (a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the resulting mixture is from 10 to 30% by weight, especially from 12 to 20% by weight, (b) this sludge mixture is treated with an aqueous solution of an organic flocculant, preferably of anionic nature, (c) the greater part of the sludge water is removed by gravity filtration, (d) the pre-dewatered sludge mixture is treated with an aqueous solution of aluminum salts or trivalent iron salts and (e) this mixture is substantially dewatered by pressure filtration, in the course of which the greater part of the petroleum present is also removed.

Sander, B.; Hovemann, F.; Scherling, K.

1983-11-29

95

POC-SCALE TESTING OF AN ADVANCED FINE COAL DEWATERING EQUIPMENT/TECHNIQUE  

SciTech Connect

The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the UKCAER will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean-coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high-sulfur and low-sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals.

B.K. PAREKH; D. TAO; J.G. GROPPO

1998-02-03

96

POC-scale testing of an advanced fine coal dewatering equipment/technique  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 pm) clean coal. Economical dewatering of an ultra-fine clean-coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

NONE

1998-09-01

97

Improved electroacoustic dewatering (EAD) belt press for food products. Phase 3, Technical progress report  

SciTech Connect

Battelle`s electroacoustic dewatering (EAD) process improves the performance of mechanical dewatering processes for several food products (such as corn fiber) by superimposing electric and ultrasonic fields. EAD has the potential to save 0.027 to 0.035 quad/yr energy by 1995 in the food processing industry, which consumed 0.15 to 0.18 quad in 1986. This report covers Phase III for demonstrating the EAD prototype on corn wet milling products (corn fiber and gluten); only Task 1 (prototype preparation and planning) was completed. EAD performance was examined in the laboratory; availability of a test site was examined. The single-roll, postdewatering EAD belt press prototype can accept material predewatered by a screw press, centrifuge, or any other mechanical dewatering device. The two-belt system, utilizing a copper-polymer cathode belt, performed as well as the three-belt system used in Phase II.

Not Available

1994-02-01

98

Reactive Sandpacks for the Attenuation of Sr-90 in Groundwater for Dewatering Applications  

NASA Astrophysics Data System (ADS)

At many nuclear sites, dewatering is necessary to facilitate building construction, the installation and repair of underground utilities, and the installation of subsurface remedial works in wet ground. When dewatering is required in areas where the groundwater contains contaminants, the proper management of large quantities of contaminated dewatering effluent can be costly and onerous. If the contamination can remain in the ground, the problems and costs of surface storage and treatment would be much reduced. Reactive sandpacks have been proposed as an alternative treatment method for Sr-90 in groundwater. In concept, reactive sandpacks are installed around the screens of dewatering wells, replacing the non-reactive conventional sand pack, such that the contaminant is altered or sorbed in the ground during the dewatering process. While the concept appears to be useful, it has not been determined whether reaction kinetics are fast enough in the fast moving water near the well-screen for satisfactory retention of the contaminant in a dewatering application. This study tested the concept of reactive sandpacks under realistic pumping conditions, by conducting in situ column experiments. Two sets of column experiments were conducted for the period of 49-55 days each, with each set composed of two 10 cm columns placed in a well at the Chalk River site. The well was screened in an actual Sr-90 groundwater plume. Columns were filled with clinoptilolite (i.e., a natural zeolite), and lowered into the well so that groundwater passed through the columns at different velocities in the range expected near the pumping well (33-200 m/day). Measurements of gross beta for the effluent water showed that the columns with higher flow velocities experienced earlier partial breakthrough of Sr-90 than the columns with lower velocities. The extent of the breakthrough of Sr-90 was also proportional to the flow velocity. Distribution coefficients, determined by fitting the normalized aqueous gross beta data to the 1-D advection-dispersion equation, varied inversely with flow velocity, suggesting that the sorption of Sr-90 onto clinoptilolite is kinetically-controlled in this high velocity range. Radioactivities for the solid samples, retrieved from the columns after the operation, showed that sorption fronts were advancing in proportion to the flow velocity, consistent with the aqueous data. The results showed that the concept can be applied to actual dewatering projects if the sandpack is properly designed. Design parameters will include thickness of the sandpacks, pumping rate, duration of the dewatering project, and concentrations of Ca and Sr. A reactive transport model is being developed to adequately incorporate sorption kinetics and provide a quantitative basis for sandpacks design.

Jeen, S.

2011-12-01

99

Development of the High-Rate Dewatering System of Bottom Sediments and Water Blooms.  

National Technical Information Service (NTIS)

In the 10th, 12th, and 13th US/Japan Experts Meetings, it was reported that the Synthetic purification system of lakes and ports using the continuous-vacuum precoat filter was most effective and economical to dewater and reuse bottom sediments and water b...

Z. Yoshino R. Sudo M. Watanabe H. Misumi S. Horiuchi

1992-01-01

100

Sludge Dewatering in a Freezing Bed: A Pilot-Scale Study.  

National Technical Information Service (NTIS)

In 1986 a pilot-scale sludge freezing bed was constructed. This bed was operated over the next three years using both an aerobically and aerobically digested sludges. These tests demonstrated that both sludges can be effectively dewatered by this process....

C. J. Diener C. J. Martel

1991-01-01

101

Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae)  

Microsoft Academic Search

Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake.

C. W. Doud; D.B. Taylor; L. Zurek

2012-01-01

102

DEVELOPMENT OF A NEW GRAVITY SEDIMENTATION PROCESS FOR DEWATERING FLUE GAS CLEANING WASTES  

EPA Science Inventory

The report gives results of a project to develop and test a novel system for dewatering flue gas cleaning (FGC) wastes at the pilot plant level. In this new system, the clarification and thickening functions are conducted in separate, but interconnected, pieces of equipment. The ...

103

DEWATERING WASTEWATER TREATMENT SLUDGE BY CLATHRATE FREEZING: A BENCH-SCALE FEASIBILITY STUDY  

EPA Science Inventory

Laboratory studies were performed to prove the concept and feasibility for a novel technology to dewater sludges. This involves the formation of solid hydrate crystals of water and specific clathrate-forming agents followed by separation of the hydrate crystal solids from the slu...

104

Anaerobically digested biosolids odor generation and pathogen indicator regrowth after dewatering  

Microsoft Academic Search

The objective of this research was to investigate whether a preferential stimulation of microorganisms in anaerobically digested biosolids can occur after dewatering and if it can lead to pathogen indicator regrowth and odor generation upon storage. Laboratory incubation simulating biosolids storage indicates that both odorant generation, based on total volatile organic sulfur compound concentrations (TVOSCs) and pathogen indicator regrowth, based

Yen-Chih Chen; Matthew J. Higgins; Steven M. Beightol; Sudhir N. Murthy; William E. Toffey

2011-01-01

105

Inferred pore pressures at the Costa Rica subduction zone: implications for dewatering processes  

Microsoft Academic Search

Drilling on Ocean Drilling Program (ODP) Leg 170, offshore Costa Rica indicates that the entire incoming sedimentary section is underthrust. Thus, observed changes in the thickness of underthrust sediments as they are progressively buried beneath the margin wedge provide a direct measure of the rate and magnitude of sediment dewatering. Laboratory consolidation tests indicate that in situ excess pore-fluid pressures

Demian M. Saffer; Eli A. Silver; Andrew T. Fisher; Harold Tobin; Kate Moran

2000-01-01

106

Evidence for episodic basin dewatering in salt-dome cap rocks  

Microsoft Academic Search

A detailed record of episodic basin-dewatering events is preserved in the anhydrite cap rocks of two Gulf Coast salt domes. Metalrich brines were intermittently expelled from geopressured zones deep in the stratigraphic section and were channeled upward along escape structures bounding the salt diapirs. Overhanging anhydrite cap rock helped to focus some escaping fluid into the zone of dissolution between

W. S. Hallager; M. R. Ulrich; J. R. Kyle; P. E. Price; W. A. Gose

1990-01-01

107

Evidence for episodic basin dewatering in salt-dome cap rocks  

Microsoft Academic Search

A detailed record of episodic basin-dewatering events is preserved in the anhydrite cap rocks to two Gulf Coast salt domes. Metal rich brines were intermittently expelled geopressured zones deep in the stratigraphic section and were channeled upward along escape structures bounding the salt diapirs. Overhanging anhydrite cap rock helped to focus some escaping fluid into the zone of dissolution between

W. S. Hallager; M. R. Ulrich; J. R. Kyle; W. A. Gose; P. E. Price

1990-01-01

108

Correlations between floc physical properties and optimum polymer dosage in alum sludge conditioning and dewatering  

Microsoft Academic Search

This paper aims to examine the correlations between floc physical properties, such as size, density, structure (in terms of fractal dimension) and optimum dosage in an alum sludge conditioning with organic polymer and also dewatering using an air pressure plate apparatus. Initially, optimum dosage was evaluated by a modified specific resistance to filtration (SRF). Thereafter, floc size, density and structure

Y. Q. Zhao

2003-01-01

109

Influence of polymer adsorption and conformation on flocculation and dewatering of kaolin suspension  

Microsoft Academic Search

This paper reports the results of the investigation on flocculation and dewatering characteristics of kaolin suspension by high molecular weight polyacrylamide flocculants of different ionic nature in the absence and the presence of some surfactants. The presence of surfactants in the system has been investigated in two modes of their addition. In the first mode, the kaolin suspension was pretreated

L. Besra; D. K. Sengupta; S. K. Roy; P. Ay

2004-01-01

110

Improved estimates of power consumption during dewatering of mine tailings using electrokinetic geosynthetics (EKGs)  

Microsoft Academic Search

Electrokinetic geosynthetics (EKGs) were developed about a decade ago, producing a material that did not experience the same corrosion problems as metal electrodes when used in electro-osmotic (EO) dewatering applications. The conductive polymeric material from which EKGs are made has the additional advantage of being able to be formed into a variety of shapes, including drainage tubes such as those

A. B. Fourie; C. J. F. P. Jones

2010-01-01

111

Sludge Dewatering and Aggregate Formation Effects through Taylor Vortex Assisted Flocculation  

Microsoft Academic Search

For polymer induced flocculation processes, the effects of flow patterns in a gap of a conical stirrer on aggregate formation and subsequent sludge dewatering efficiency were analysed. Different flow regimes were identified by lab scale investigations with model substances and summarized in a Ta and Re number plane. An enhancement of sludge dewaterability for polymer induced flocculation processes was identified

Michael Sievers; Soledad M. Stoll; Christian Schroeder; Michael Niedermeiser; Theodore I. Onyeche

2008-01-01

112

Influences of Extracellular Polymeric Substances (EPS) on Flocculation, Settling, and Dewatering of Activated Sludge  

Microsoft Academic Search

Results in over 200 publications related to constituents, quantities, and characteristics of extracellular polymeric substances (EPS) in activated sludge and their influences on sludge flocculation, settling, and dewatering are compiled and analyzed. Constituents and quantities of EPS are strongly dependent on the extraction process. Most results show that EPS in activated sludge comprise substantially more proteins than carbohydrates. EPS and

Yan Liu; Herbert H. P. Fang

2003-01-01

113

Particle characteristics and their influence on dewatering of kaolin, calcite and quartz suspensions  

Microsoft Academic Search

The effect of particle properties and dispersion on the filtration and dewatering behaviour of three different minerals namely kaolin, calcite and quartz in aqueous media have been examined. The primary particle properties such as particle size, size distribution, specific surface area, density, surface structure, dry bed porosities and sphericities of particles as well as their dispersion properties like solid concentration,

L. Besra; D. K. Sengupta; S. K. Roy

2000-01-01

114

Parameter investigation for decentralised dewatering and solar thermic drying of sludge.  

PubMed

The purpose of this paper is an experimental and model assisted investigation of the capabilities of a dewatering system for sewage sludge for decentralised sites. Laboratory and field tests are performed with different initial conditions and the influences of filter medium, initial height, initial total suspended solids, temperature and relative humidity are discussed. The experimental work shows the feasibility of geotextile media for dewatering high water content sewage sludge and that the textile structure is of secondary importance. The specific filter resistance of the sludge cake is found to be the most significant factor in dewatering applications. The mathematical description of the dewatering process is based on the superposition of two models, the Conventional Filtration Theory for the filtration phase and the BT-model for the drying phase. Feasibility and limits of the theoretical approach are evaluated by means of a comparison between measurements and simulated data of cyclic reloading tests. It is found that a better filtration efficiency is achieved at higher TSS and at lower initial height of the slurry layer. Due to the viscosity decrease, a higher temperature enhances not only evaporation, but also filtration rate. PMID:16104407

Wett, B; Demattio, M; Becker, W

2005-01-01

115

An Approach for the Laboratory Investigation of Coarse Coal Dewatering by Centrifugation  

Microsoft Academic Search

In many coal preparation plants, basket centrifuges are used for dewatering coarse coal after it has been cleaned. As part of a large Australian Minerals Industries Research Association (AMIRA) project, a laboratory batch centrifuge test has been developed to provide a reproducible procedure to quantify the moisture retention properties of black coals. The final moisture content after prolonged centrifugation, termed

E. T. WHITE; L. K. KAISER; Y. HE; B. JENSEN; B. R. STANMORE; B. A. FIRTH

1996-01-01

116

Precision Dual-Aquifer Dewatering at a Low Level Radiological Cleanup in New Jersey  

SciTech Connect

Cleanup of low-level radioactive wastes at the Wayne Interim Storage Site (WISS), Wayne, New Jersey during the period October, 2000 through November, 2001 required the design, installation and operation of a dual-aquifer dewatering system to support excavation of contaminated soils. Waste disposal pits from a former rare-earth processing facility at the WISS had been in contact with the water table aquifer, resulting in moderate levels of radionuclides being present in the upper aquifer groundwater. An uncontaminated artesian aquifer underlies the water table aquifer, and is a localized drinking water supply source. The lower aquifer, confined by a silty clay unit, is flowing artesian and exhibits potentiometric heads of up to 4.5 meters above grade. This high potentiometric head presented a strong possibility that unloading due to excavation would result in a ''blowout'', particularly in areas where the confining unit was < 1 meter thick. Excavation of contaminated materials w as required down to the surface of the confining unit, potentially resulting in an artesian aquifer head of greater than 8 meters above the excavation surface. Consequently, it was determined that a dual-aquifer dewatering system would be required to permit excavation of contaminated material, with the water table aquifer dewatered to facilitate excavation, and the deep aquifer depressurized to prevent a ''blowout''. An additional concern was the potential for vertical migration of contamination present in the water table aquifer that could result from a vertical gradient reversal caused by excessive pumping in the confined system. With these considerations in mind, a conceptual dewatering plan was developed with three major goals: (1) dewater the water table aquifer to control radionuclide migration and allow excavation to proceed; (2) depressurize the lower, artesian aquifer to reduce the potential for a ''blowout''; and (3) develop a precise dewatering level control mechanism to insure a vertical gradient reversal did not result in cross-contamination. The plan was executed through a hydrogeologic investigation culminating with the design and implementation of a complex, multi-phased dual-aquifer dewatering system equipped with a state of the art monitoring network.

Gosnell, A. S.; Langman, J. W. Jr.; Zahl, H. A.; Miller, D. M.

2002-02-27

117

Application of the severity parameter for predicting viscosity during hydrothermal processing of dewatered sewage sludge for a commercial PFBC plant  

Microsoft Academic Search

Dewatered sewage sludge (approximately 80% water, but with low fluidity) was liquidized by hydrothermal treatment in order to make coal–water paste (CWP) for use in a pressurized-fluidized-bed-combustion (PFBC) power plant. Prediction of the viscosity of the dewatered sewage sludge during batch reactor hydrothermal liquefaction is important in order to avoid inputting excess energy. A single parameter, the severity parameter, has

Takashi Yanagida; Shinji Fujimoto; Tomoaki Minowa

2010-01-01

118

A case study on stratified settlement and rebound characteristics due to dewatering in Shanghai subway station.  

PubMed

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed. PMID:23878521

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-05-19

119

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal  

SciTech Connect

Battelle (Columbus, Ohio) undertook development of its electro-acoustic (EAD) process to demonstrate its commercial potential for continuous dewatering of fine and ultrafine coals. The pilot plant and laboratory results, provided in this report, show that a commercial-size EAD machine is expected to economically achieve the dewatering targets for {minus}100 mesh and {minus}325 mesh coals. The EAD process utilizes a synergistic combination of electric and acoustic (e.g., ultrasonic) fields in conjunction with conventional mechanical processes, such as belt presses, screw presses, plate and frame filter presses, and vacuum filters. The application of EAD is typically most beneficial after a filter cake is formed utilizing conventional mechanical filtration. (VC)

Chauhan, S.P.; Kim, B.C.; Menton, R.; Senapati, N.; Criner, C.L.; Jirjis, B.; Muralidhara, H.S.; Chou, Y.L.; Wu, H.; Hsieh, P. (Battelle, Columbus, OH (United States)); Johnson, H.R.; Eason, R. (Ashbrook-Simon-Hartley Corp., Houston, TX (United States)); Chiang, S.M.; Cheng, Y.S. (Pittsburgh Univ., PA (United States)); Kehoe, D. (CQ, Inc., Homer City, PA (United States))

1991-10-31

120

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal. Final report  

SciTech Connect

Battelle (Columbus, Ohio) undertook development of its electro-acoustic (EAD) process to demonstrate its commercial potential for continuous dewatering of fine and ultrafine coals. The pilot plant and laboratory results, provided in this report, show that a commercial-size EAD machine is expected to economically achieve the dewatering targets for {minus}100 mesh and {minus}325 mesh coals. The EAD process utilizes a synergistic combination of electric and acoustic (e.g., ultrasonic) fields in conjunction with conventional mechanical processes, such as belt presses, screw presses, plate and frame filter presses, and vacuum filters. The application of EAD is typically most beneficial after a filter cake is formed utilizing conventional mechanical filtration. (VC)

Chauhan, S.P.; Kim, B.C.; Menton, R.; Senapati, N.; Criner, C.L.; Jirjis, B.; Muralidhara, H.S.; Chou, Y.L.; Wu, H.; Hsieh, P. [Battelle, Columbus, OH (United States); Johnson, H.R.; Eason, R. [Ashbrook-Simon-Hartley Corp., Houston, TX (United States); Chiang, S.M.; Cheng, Y.S. [Pittsburgh Univ., PA (United States); Kehoe, D. [CQ, Inc., Homer City, PA (United States)

1991-10-31

121

Dewatering studies of fine clean coal. [Quarterly] technical report, December 1, 1991--February 29, 1992  

SciTech Connect

Physical cleaning of ultra-fine coal using an advanced froth flotation techniques provides a low ash product, however, due to high surface area of particles the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. The studies have identified a combination of metal ion and surfactant found to be effective in providing a 22 percent moisture filter cake.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research

1992-08-01

122

A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station  

PubMed Central

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

123

Method for simultaneous use of a single additive for coal flotation, dewatering and reconstitution  

SciTech Connect

A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

Wen, Wu-Wey; Gray, M.L.; Champagne, K.J.

1993-11-09

124

Effects of sludge properties on the thickening and dewatering of waste activated sludge.  

PubMed

The thickening and dewatering of waste activated sludge, from a pilot-scale submerged membrane bioreactor and two bench-scale, complete-mix activated sludge reactors (high-shear and low-shear aeration) treating the same municipal primary effluent, were investigated. Solids settling and compaction were measured using the diluted sludge volume index (DSVI) analysis and a batch centrifugation analysis, respectively. Elevated levels of filamentous microorganisms resulted in higher DSVI values and lower centrifuged pellet concentration. Elevated levels of nocardioform bacteria resulted in lower solids float concentrations, and higher colloidal material reduced solids recovery in batch flotation experiments. Sludge filterability, measured as time-to-filter, was shown to be a function of extracelluar polymeric substances and colloidal material, where higher levels of either reduced sludge filterability. Additional research is necessary to confirm these results using full- or demonstration-scale thickening and dewatering units. PMID:18044358

Merlo, Rion P; Trussell, R Shane; Hermanowicz, Slawomir W; Jenkins, David

2007-11-01

125

Dewatering studies of fine clean coal. Technical report, September 1, 1991--November 30, 1991  

SciTech Connect

Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop the process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. During the last year`s effort, it was reported that a combination of metal ion and surfactant provided a 22 percent moisture filter cake.

Parekh, B.K.

1991-12-31

126

Review of Design Approaches Applicable to Dewatering Uranium Mill Tailings Disposal Pits  

SciTech Connect

This report is a review of design approaches in the literature that may be applicable to uranium mill tailings drainage. Tailings dewatering is required in the deep mined-out pits used for wet tailings disposal. Agricultural drainage theory is reviewed because it is seen as the most applicable technology. It is concluded that the standard drain-pipe envelope design criteria should be easily adapted. The differences in dewatering objectives and physical characteristics between agricultural and tailings drainage systems prevent direct technology transfer with respect to drain spacing calculations. Recommendations for further research are based on the drainage features unique to uranium mill tailings. It is recommended that transient solutions be applied to describe liquid movement through saturated and partially saturated tailings. Modeling should be used to evaluate the benefits of drainage design approaches after careful consideration of potential construction problems.

Gutknecht, P. J.; Gates, T. E.

1982-03-01

127

Dewatering of high-moisture wood chips by roller compression method  

Microsoft Academic Search

In seeking an efficient method for drying very wet chips, we developed and tested an original continuous dewatering system using mechanical compression (10–30MPa). The moisture content of cedar chips decreased from 100–270% to 85–130% (dry basis), and the energy required to remove the water was 9% (power consumption basis) and 25% (primary energy basis) for heat energy to evaporate the

Takahiro Yoshida; Hiroyuki Sasaki; Tsutomu Takano; Osamu Sawabe

2010-01-01

128

Interfacial chemistry and particle interactions and their impact upon the dewatering behaviour of iron oxide dispersions  

Microsoft Academic Search

The influence of interfacial chemistry and particle interactions on sedimentation and electroosmosis (EO) of coagulated iron oxide dispersions has been investigated. Both pH and ionic strength of NH4Cl electrolyte had a profound effect on the particle electrokinetic zeta potential and dispersion rheological behaviour (shear yield stress), impacting strongly on the dewatering behaviour. In the absence of NH4Cl, the zeta potential

Jonas Addai-Mensah; John Ralston

2004-01-01

129

Hydrophobic Dewatering of Fine Coal. Topical report, March 1, 1995-March 31, 1997  

SciTech Connect

Many advanced fine coal cleaning technologies have been developed in recent years under the auspices of the U.S. Department of Energy. However, they are not as widely deployed in industry as originally anticipated. An important reason for this problem is that the cleaned coal product is difficult to dewater because of the large surface area associated with fine particles. Typically, mechanical dewatering, such as vacuum filtration and centrifugation, can reduce the moisture to 20-35% level, while thermal drying is costly. To address this important industrial problem, Virginia Tech has developed a novel dewatering process, in which water is displaced from the surface of fine particulate materials by liquid butane. Since the process is driven by the hydrophobic interaction between coal and liquid butane, it was referred to as hydrophobic dewatering (HD). A fine coal sample with 21.4 pm median size was subjected to a series of bench-scale HD tests. It was a mid-vol bituminous coal obtained from the Microcel flotation columns operating at the Middle Fork coal preparation plant, Virginia. All of the test results showed that the HD process can reduce the moisture to substantially less than 10%. The process is sensitive to the amount of liquid butane used in the process relative to the solids concentration in the feed stream. Neither the intensity nor the time of agitation is critical for the process. Also, the process does not require long time for phase separation. Under optimal operating conditions, the moisture of the fine coal can be reduced to 1% by weight of coal.

Yoon, R.; Sohn, S.; Luttrell, J.; Phillips, D.

1997-12-31

130

Increases in fecal coliform bacteria resulting from centrifugal dewatering of digested biosolids.  

PubMed

In many countries, the classification of biosolids for disposal purposes can be based, in part, on fecal coliform levels, with alternative criteria also available based on the stabilization process used, such as anaerobic digestion. The assumption that these alternative criteria provide equivalent protection may be flawed. This paper demonstrates that fecal coliform levels determined after digestion do not always indicate the bacterial levels after the same biosolids have been dewatered by centrifugation. In samples from mesophilic digestion, half had significant increases in coliform numbers (P<0.05) with up to one order of magnitude increase during centrifugation, suggesting coliform regrowth. Thermophilically digested samples had significant increases of several orders of magnitude during dewatering, more likely from reactivation of viable but non-culturable coliforms than from regrowth. In other cases, centrifugation induced coliform regrowth or reactivation upon incubation and storage of dewatered samples, but not digested samples. These 2-3 order of magnitude increases occurred with both 25 and 37 degrees C incubations. Coliform increases continued for up to 5 days, then gradually declined. However, by day 20 coliform numbers were still 2 orders of magnitude greater than when originally sampled. The magnitude of the increases could be due either to regrowth or reactivation, but the nature of the longer-term increases--also seen in biosolids/soil mixtures--suggests regrowth. Differences in numbers between digested and dewatered samples could not be duplicated with high shear processing in lab-scale devices, with nitrogen purging to remove volatile or gaseous constituents, or with redilution using centrate. They could not be attributed to enumeration methods, to interference of Bacillus spp. on apparent coliform counts, or to temperature changes. The increases have practical implications in the use of fecal coliform or alternative criteria to define pathogen content in biosolids. PMID:17188734

Qi, Yinan; Dentel, Steven K; Herson, Diane S

2006-12-26

131

Dewatering of petroleum-containing sludges with recovery of the oil component  

Microsoft Academic Search

A process is disclosed for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein (a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the

B. Sander; F. Hovemann; K. Scherling

1983-01-01

132

Automation in sludge dewatering by novel on-line characterisation of flocculation  

Microsoft Academic Search

A novel on-line method and system for characterisation of sludge flocs in view of improving sludge dewatering has been developed. The characterisation of sludge flocs was carried out after the conditioning or the flocculation process. The system uses a conventional CCD-line scan camera providing an on-line monitoring of the relative floc size distribution by image processing procedures. The image processing

M. Sievers; C. Schroeder; H. Bormann; T. I. Onyeche; O. Schlaefer; S. Schaefer

133

High resolution imaging of de-watering structures in western Lake Superior  

NASA Astrophysics Data System (ADS)

A reconnaissance multibeam sonar survey conducted in northwestern Lake Superior, off the western coast of Isle Royale, revealed that the character of lake floor in this region, which covers over 2000 sq km, is controlled by the extensive development of lake floor features which are most likely associated with fluid escaping from the lake floor sediments. The southern half of this area is characterized by the development of extensive fields of ring-shaped depressions. These are up to 300 m across, 25 to 50 m wide and 1 to 5 m deep. The lake-floor on the interior of the ring is at the same depth as the surrounding lake floor. The rings arrange themselves in networks in which the individual rings do not intersect each other. The high-resolution bathymetry data revealed that the rings are made up from chains of pockmarks. Traced northward, the networks of rings disappear and are replaced by isolated rings. These in turn are replaced by isolated pockmarks. The changes in the character of the lake floor dewatering features observed in Isle Royale Trough suggests that the nature of the de-watering event also changed in the same direction. To test this hypothesis, high-resolution seismic profiles were collected with an Edgetech CHIRP sub-bottom profiler over selected targets in the area previously surveyed by the multibeam sonar. The results of the experiment reveal that the sub-surface character of the de-watering event varies across the survey area. In some cases it appears that fluid has flowed along isolated chimneys. These often terminate in surface (or near-surface) pocks. Localized amplitude fluctuations in the data about the central chimney structure suggest that fluid has flowed laterally to the chimney. In other areas, the widespread development of amplitude perturbations of the sub-surface reflections suggests that the de-watering was pervasive without any localization to form a chimney.

Wattrus, N. J.; Lewis, C.; Beer, J.

2005-12-01

134

Monitoring and optimizing the co-composting of dewatered sludge: a mixture experimental design approach.  

PubMed

The management of dewatered wastewater sludge is a major issue worldwide. Sludge disposal to landfills is not sustainable and thus alternative treatment techniques are being sought. The objective of this work was to determine optimal mixing ratios of dewatered sludge with other organic amendments in order to maximize the degradability of the mixtures during composting. This objective was achieved using mixture experimental design principles. An additional objective was to study the impact of the initial C/N ratio and moisture contents on the co-composting process of dewatered sludge. The composting process was monitored through measurements of O(2) uptake rates, CO(2) evolution, temperature profile and solids reduction. Eight (8) runs were performed in 100 L insulated air-tight bioreactors under a dynamic air flow regime. The initial mixtures were prepared using dewatered wastewater sludge, mixed paper wastes, food wastes, tree branches and sawdust at various initial C/N ratios and moisture contents. According to empirical modeling, mixtures of sludge and food waste mixtures at 1:1 ratio (ww, wet weight) maximize degradability. Structural amendments should be maintained below 30% to reach thermophilic temperatures. The initial C/N ratio and initial moisture content of the mixture were not found to influence the decomposition process. The bio C/bio N ratio started from around 10, for all runs, decreased during the middle of the process and increased to up to 20 at the end of the process. The solid carbon reduction of the mixtures without the branches ranged from 28% to 62%, whilst solid N reductions ranged from 30% to 63%. Respiratory quotients had a decreasing trend throughout the composting process. PMID:21565440

Komilis, Dimitrios; Evangelou, Alexandros; Voudrias, Evangelos

2011-05-11

135

Evaluation of hyperbaric filtration for fine coal dewatering. Quarterly technical progress report, 1996  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases, namely Phase I, model development, Phase II, laboratory studies, Phase III, field testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase 11, and Consol Inc. in Phase III of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase I and II will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit. Accomplishments to date are reported for the three phases.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL, Inc., Pittsburgh, PA (United States)

1996-12-31

136

Efficient Calculation of Dewatered and Entrapped Areas Using Hydrodynamic Modeling and GIS  

SciTech Connect

River waters downstream of a hydroelectric project are often subject to rapidly changing discharge. Abrupt decreases in discharge can quickly dewater and expose some areas and isolate other areas from the main river channel, potentially stranding or entrapping fish, which often results in mortality. A methodology is described to estimate the areas dewatered or entrapped by a specific reduction in upstream discharge. A one-dimensional hydrodynamic model was used to simulate steady flows. Using flow simulation results from the model and a geographic information system (GIS), estimates of dewatered and entrapped areas were made for a wide discharge range. The methodology was applied to the Hanford Reach of the Columbia River in central Washington State. Results showed that a 280 m$^3$/s discharge reduction affected the most area at discharges less than 3400 m$^3$/s. At flows above 3400 m$^3$/s, the affected area by a 280 m$^3$/s discharge reduction (about 25 ha) was relatively constant. A 280 m$^3$/s discharge reduction at lower flows affected about twice as much area. The methodology and resulting area estimates were, at the time of writing, being used to identify discharge regimes, and associated water surface elevations, that might be expected to minimize adverse impacts on juvenile fall chinook salmon (\\emph{Oncorhynchus tshawytscha}) that rear in the shallow near-shore areas in the Hanford Reach.

Richmond, Marshall C.; Perkins, William A.

2009-12-01

137

Dewatering studies of fine clean coal. Final technical report, September 1, 1991--August 31, 1992  

SciTech Connect

Physical cleaning of ultra-fine coal using advanced froth flotation technique provides a low ash product; however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of the advanced flotation processes. The main objective of the present research program is to study and understand dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach utilized synergistic effect of metal ions and surfactant addition to lower the moisture of clean coal using the conventional vacuum dewatering technique. The studies have identified a combinations of metal ions and surfactants in providing a 22 percent moisture filter cake. Surface chemical study indicated a direct correlation between the point-of-zero charge (PZC) of metal ion/fine coal system and lowering of moisture in the filter cake. Adsorption of either metal ions or surfactants alone did not provide a significant reduction of moisture in the filter cake. However, a combination of the two provided a filter cake containing about 22 percent moisture. Filtration tests conducted using a laboratory vacuum drum filter indicated that the results obtained in batch filtration could be reproduced on a continuous filtration unit. FT-IR studies indicated that anionic surfactant and metal ions form complex species which adsorbs on the fine coal and results in improved moisture reduction during filtration. Recommendations are offered for testing this novel dewatering process on a pilot scale at a coal preparation plant in Illinois.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research

1992-12-31

138

Performance of an anaerobic baffled reactor and hybrid constructed wetland treating high-strength wastewater in Nepal—A model for DEWATS  

Microsoft Academic Search

Centralized wastewater treatment systems require sophisticated technologies and skilled manpower for their operation and maintenance (O&M). These systems have huge construction as well as O&M costs. Therefore, a Decentralized Wastewater Treatment System (DEWATS) rather than a centralized system might be especially beneficial in developing countries. A model for DEWATS is developed in Nepal with Anaerobic Baffled Reactor (ABR) and hybrid

Shirish Singh; Raimund Haberl; Otto Moog; Roshan Raj Shrestha; Prajwal Shrestha; Rajendra Shrestha

2009-01-01

139

Textural evidence for jamming and dewatering of a sub-surface, fluid-saturated granular flow  

NASA Astrophysics Data System (ADS)

Sand injectites are spectacular examples of large-scale granular flows involving migration of hundreds of cubic meters of sand slurry over hundreds of meters to kilometers in the sub-surface. By studying the macro- and microstructural textures of a kilometer-scale sand injectite, we interpret the fluid flow regimes during emplacement and define the timing of formation of specific textures in the injected material. Fluidized sand sourced from the Santa Margarita Fm., was injected upward into the Santa Cruz Mudstone, Santa Cruz County, California. The sand injectite exposed at Yellow Bank Beach records emplacement of both hydrocarbon and aqueous sand slurries. Elongate, angular mudstone clasts were ripped from the wall rock during sand migration, providing evidence for high velocity, turbid flow. However, clast long axis orientations are consistently sub-horizontal suggesting the slurry transitioned to a laminar flow as the flow velocity decreased in the sill-like intrusion. Millimeter to centimeter scale laminations are ubiquitous throughout the sand body and are locally parallel to the mudstone clast long axes. The laminations are distinct in exposure because alternating layers are preferentially cemented with limonite sourced from later groundwater infiltration. Quantitative microstructural analyses show that the laminations are defined by subtle oscillations in grain alignment between limonite and non-limonite stained layers. Grain packing, size and shape distributions do not vary. The presence of limonite in alternating layers results from differential infiltration of groundwater, indicating permeability changes between the layers despite minimal grain scale differences. Convolute dewatering structures deform the laminations. Dolomite-cemented sand, a signature of hydrocarbon saturation, forms irregular bodies that cross-cut the laminations and dewatering structures. Laminations are not formed in the dolomite-cemented sand. The relative viscosity difference between the hydrocarbon and aqueous sand slurries controls the the critical radius of the contacts between dolomite cemented and limonite cemented sand bodies. The cross-cutting relationships established in the field show that the laminations formed at the jamming transition in the aqueous sand slurry. We interpret the laminations as preserving evidence for dynamic permeability instabilities in the dewatering slurry. Relatively high permeability channels formed as pore fluid flow rearranged grains during initial dewatering. Once initiated, the flow localized further into the higher permeability channels resulting in a feedback that caused the permeability in the channels to increase.

Sherry, T. J.; Rowe, C. D.; Kirkpatrick, J. D.; Brodsky, E. E.

2011-12-01

140

Suspended Sediment, Carbon and Nitrogen Fluxes during the Dewatering of a Low-Head Impoundment and a Subsequent Flood Event  

NASA Astrophysics Data System (ADS)

Previous to dam removal, for restoration purposes, a low-head impoundment was dewatered (28 April 2005) during baseflow conditions using existing flood gates. Approximately one week later (6 May 2005) a near bankfull event passed through the recently dewatered system. Inputs upstream of the impoundment accounted for 657 kg of TSS during the 30 hours of dewatering. The impoundment was a point source of TSS contributing and additional 1.08 tonnes to the system at a rate of 35.9 kg hr-1. Reach-level fluxes of dissolved organic carbon (DOC) and dissolved N were also amended by the impoundment with 422 kg and 41 kg respectively. Upstream sources supplied 1094 kg of DOC and 105 kg of N to the impounded section of the reach. These impoundment contributions were supplied at rates of 14.08 kg hr-1 for DOC and 1.39 kg hr-1 for N. In contrast, during the 6 day flood event the impoundment acted as a sink for TSS by storing 31.4 tonnes. During this same event the impoundment contributed 6.4 tonnes of DOC and 0.70 tonnes of N to downstream environments at rates of 48.96 kg hr-1 and 5.39 kg hr-1 respectively. Upstream loading provided 38.2 tonnes of DOC and 2.8 tonnes of N. These data suggest that dissolved C and N are not subjected to the same transport limitations as TSS. Further, the dewatering of this particular dam (during baseflow conditions) impacted downstream water chemistry less than the subsequent flood event in both mass and rate of loading. These data support the concept that post-dewatering/removal flood events have the potential to act as a more significant disturbance than the actual removal/dewatering if the flood occurs within the `window of sensitivity' during the initial phases of system recovery.

Riggsbee, J. A.; Julian, J. P.; Doyle, M. W.; Wetzel, R. G.

2005-12-01

141

Process for utilizing a pumpable fuel from highly dewatered sewage sludge  

SciTech Connect

A process is described for disposing of sewage sludge comprising: (1) dewatering an aqueous slurry of sewage sludge having a solids content of at least about 3 wt. % to produce an aqueous slurry of sewage sludge having a solids content in the range of about 5 to 20 wt. %; (2) pressing and/or centrifuging the dewatered slurry of sewage sludge from (1) to produce amorphous sewage sludge having a solids content in the range of about 28 to 50 wt. %; (3) heating the amorphous sewage sludge from (2) in a closed pressure vessel at a temperature in the range of about 150 F to 510 F in the absence of air for a period in the range of about 3 seconds to 60 minutes and shearing the sewage sludge by a rotor/mixer operating at a speed in the range of about 15 to 100 rpm, thereby producing a pumpable slurry of sewage sludge having a viscosity in the range of about 400 to 1,500 centipoise when a measured at 200 F and a higher heating value in the range of about 5,000 to 9,500 Btu/lb, dry basis; and (4) burning said pumpable slurry from (3) in a partial oxidation gasifier, furnace, boiler, or incinerator to produce an effluent gas stream.

Khan, M.R.

1993-08-10

142

Anaerobically digested biosolids odor generation and pathogen indicator regrowth after dewatering.  

PubMed

The objective of this research was to investigate whether a preferential stimulation of microorganisms in anaerobically digested biosolids can occur after dewatering and if it can lead to pathogen indicator regrowth and odor generation upon storage. Laboratory incubation simulating biosolids storage indicates that both odorant generation, based on total volatile organic sulfur compound concentrations (TVOSCs) and pathogen indicator regrowth, based on fecal coliform densities follow similar formation and reduction patterns. The formation and reduction patterns of both odor compounds and fecal coliforms imply that groups of microorganism are induced if shearing disturbance is imposed during dewatering, but a secondary stabilization can be achieved soon after 1-2 weeks of storage. The occurrence of the induction is likely the microbial response to substrate release and environmental changes, such as oxygen, resulting from centrifuge shearing. The new conditions favor the growth of fecal coliforms and odor producing bacteria, and therefore, results in the observed fecal coliforms regrowth and odor accumulation during subsequent storage. However, when both substrate and oxygen deplete, a secondary stabilization can be achieved, and both odor and fecal coliforms density will drop. PMID:21388653

Chen, Yen-Chih; Higgins, Matthew J; Beightol, Steven M; Murthy, Sudhir N; Toffey, William E

2011-02-19

143

Diagenesis, dewatering, and source rock potential of Ordovician shales from the High Atlas, Morocco  

SciTech Connect

The Ordovician shales of the High Atlas are interpreted as shelf sediments. They contain uncommon thin, wave-rippled, fine sandstone layers which record rare high-energy event and are attributed to winter storm action. The shales coarsen upward and the sandstone horizons become more common toward the top of the sequence, reflecting increasing proximality up the sequence from an outer to a mid-shelf setting. In places the shales contain large ferroan carbonate concretions. These have been analyzed together with the shales to determine the diagenetic and dewatering history of the sequence. Comparison of the chemistry of the noncarbonate fraction within the concretions with that of the host shales has led to quantitative mass-transfer models for the system. These suggest the sequence was an important source of cementing components (e.g., Ca, Si) for adjacent potential reservoir rocks. Other elements (e.g., Al, Mg, K) have not moved out of the system; the shales were not therefore a source for authigenic aluminosilicates as is often supposed. The major transport/dewatering pathways were the interbedded storm-sandstone horizons. These are now extensively quartz cemented. Local synsedimentary faults were probably also important conduits. These results have important implications regarding the relationship between shale and sandstone diagenesis. The shales presently contain up to 1% TOC. In the study area, however, they are thermally postmature with respect to hydrocarbon generation. Equivalent rocks which have experienced less burial should be considered potential source rocks.

Evans, I.J.

1988-08-01

144

Predicting Spread of Invasive Exotic Plants into Dewatered Reservoirs after Dam Removal on the Elwha River, Olympic National Park, Washington.  

National Technical Information Service (NTIS)

The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam rem...

A. Woodward C. Torgersen J. Chenoweth K. Beirne S. Acker

2011-01-01

145

A simplified parameter extraction technique using batch settling data to estimate suspension material properties in dewatering applications  

Microsoft Academic Search

Batch settling tests are considered in order to obtain dewatering material properties of suspensions\\/sludges towards the low end of the range of solids fractions. Plausible functional forms are considered for fitting batch settling test (height vs. time) data. In particular, power law and exponential decay functions are shown to be reasonable fits to simulated synthetic batch settling data. These forms

P. Grassia; S. P. Usher; P. J. Scales

2008-01-01

146

Preliminary estimates of effects of uranium-mine dewatering on water levels, San Juan Basin. [Code SJBRUS  

Microsoft Academic Search

Most of the uranium mines in northwestern New Mexico will withdraw water from the Morrison Formation in the course of mining operations. Using three levels of projected uranium mining, a digital model was used to estimate approximate dewatering rates, effects on water levels in the Morrison Formation, and effects on streams to the year 2000. All effects are superimposed on

F. P. Lyford; P. F. Frenzel; W. J. Stone

1980-01-01

147

Efficient and stable nitritation and denitritation of ammonium-rich sludge dewatering liquor using an SBR with continuous loading  

Microsoft Academic Search

Separate treatment of dewatering liquor from anaerobic sludge digestion significantly reduces the nitrogen load of the main stream and improves overall nitrogen elimination. Such ammonium-rich wastewater is particularly suited to be treated by high rate processes which achieve a rapid elimination of nitrogen with a minimal COD requirement. Processes whereby ammonium is oxidised to nitrite only (nitritation) followed by denitritation

Christian Fux; Silvana Velten; Valeria Carozzi; David Solley; Jürg Keller

2006-01-01

148

Use of dewatered alum sludge as main substrate in treatment reed bed receiving agricultural wastewater: Long-term trial  

Microsoft Academic Search

This study aims to explore a novel application of dewatered alum sludge cakes (DASC) as the main medium in a single model reed bed to treat phosphorus-rich animal farm wastewater under “tidal flow” operation on a long-term basis. It is expected that the cakes act as the carrier for developing biofilm and also serve as adsorbent to enhance phosphorus (P)

Y. Q. Zhao; X. H. Zhao; A. O. Babatunde

2009-01-01

149

Evaluation of hyperbaric filtration for fine coal dewatering. Fifth quarterly technical progress report, October 1, 1993--December 31, 1993  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases: model development; laboratory studies; and field testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase II, and Consol Inc. in Phase III of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in phase I and 11 will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit. In this report, dewatering model development and laboratory studies are presented.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Research Foundation; Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL, Inc., Library, PA (United States)

1993-12-31

150

Technical, economic, and environmental aspects of rotating cup atomization and dewatering of coal\\/water slurry mixtures  

Microsoft Academic Search

Coal\\/water slurry rotating cup to atomization and dewatering are examined in an integrated research effort which addresses the technical, economic, and environmental aspects of the operation. The development and current state of the art in rotary atomization are reviewed. A theoretical model of the flow of a slurry of uniform consistency in a rotating cup was developed and compared to

Marnicio

1984-01-01

151

Development and Testing of a Novel Mechanical Device for Dewatering Peat. Quarterly Technical Progress Report, July 1-September 30, 1985.  

National Technical Information Service (NTIS)

In Phase I, a bench-scale IRC press was designed fabricated, and tested. The results obtained from the testing of the bench-scale IRC press (3 inch-diameter outer roll and 2 inch-diameter inner roll) demonstrated that the IRC press can dewater the peat to...

1986-01-01

152

Bedrock Subsidence Associated with Mine-dewatering Identified by InSAR in Central Nevada  

NASA Astrophysics Data System (ADS)

During the past decade, synthetic aperture radar interferometry, or InSAR, has proven to be an invaluable tool in the geosciences. However, it was not until recently that InSAR has been used extensively for the delineation of groundwater related subsidence bowls. Groundwater related InSAR studies such as Amelung et al. (1999) as well as others have demonstrated the vastly improved spatial resolution afforded by InSAR relative to traditional surveying techniques. This has allowed for further understanding of the complexity of subsidence bowls and the role of secondary factors such as structure, aquifer material properties and other previously unforeseen factors. Ground subsidence related to mine dewatering is a common occurrence due to the large volumes of water that are typically pumped in order to lower the local groundwater table to facilitate the excavation of open pit and underground mines. Several mines along the Carlin Trend of Central Nevada have produced distinct InSAR signals of greater aerial extent and magnitude than most municipal groundwater signals. One signal in particular shows a minimum of 54 cm of dewatering related subsidence between June 1, 1992 and September 21, 2000. A small area of uplift also exists in the vicinity of where groundwater is being reintroduced into the subsurface. The aerial extent of the subsidence feature is impressive as it extends as far as 20 km away from the location of the extraction wells used for dewatering. The deformation signal correlates somewhat well with the observed groundwater drawdown pattern. However, since the spatial resolution of the InSAR is much better than that of the monitoring well locations, the complexity of the signal is better delineated. The large aerial extent is likely a result of the fact that the vast majority of the pumping in the area is from the deeper carbonate aquifer, with very small amounts of pumping from shallower siltstones and unconsolidated basin fill. Of most interest is the fact that this extensive subsidence bowl extends into bedrock. Groundwater related bedrock subsidence of this scale is rarely, if ever, observed, and therefore, poorly understood. Future work at this site will be focused on better understanding the mechanics of the observed bedrock subsidence, and possible implications to other high volume groundwater pumping sites.

Katzenstein, K. W.; Bell, J. W.

2006-12-01

153

Prediction and verification of centrifugal dewatering of P. pastoris fermentation cultures using an ultra scale-down approach.  

PubMed

Recent years have seen a dramatic rise in fermentation broth cell densities and a shift to extracellular product expression in microbial cells. As a result, dewatering characteristics during cell separation is of importance, as any liquor trapped in the sediment results in loss of product, and thus a decrease in product recovery. In this study, an ultra scale-down (USD) approach was developed to enable the rapid assessment of dewatering performance of pilot-scale centrifuges with intermittent solids discharge. The results were then verified at scale for two types of pilot-scale centrifuges: a tubular bowl equipment and a disk-stack centrifuge. Initial experiments showed that employing a laboratory-scale centrifugal mimic based on using a comparable feed concentration to that of the pilot-scale centrifuge, does not successfully predict the dewatering performance at scale (P-value <0.05). However, successful prediction of dewatering levels was achieved using the USD method (P-value ?0.05), based on using a feed concentration at small-scale that mimicked the same height of solids as that in the pilot-scale centrifuge. Initial experiments used Baker's yeast feed suspensions followed by fresh Pichia pastoris fermentation cultures. This work presents a simple and novel USD approach to predict dewatering levels in two types of pilot-scale centrifuges using small quantities of feedstock (<50 mL). It is a useful tool to determine optimal conditions under which the pilot-scale centrifuge needs to be operated, reducing the need for repeated pilot-scale runs during early stages of process development. PMID:22442107

Lopes, A G; Keshavarz-Moore, E

2012-03-22

154

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 6, January--March 1996  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1- March 31, 1996.

Tao, D.; Groppo, J.G.; Parekh, B.K.

1996-05-03

155

Recovered oil dewatering process and apparatus with water vaporizing in blowdown drum  

SciTech Connect

In a refinery that contains a delayed coker unit, a process is described for dewatering and recovering valuable products from a refinery recovered oil stream containing water generated from sources outside the delayed coker unit, comprising the steps of: introducing the recovered oil stream into a blowdown drum also used for receiving overhead vapor and liquids from a coke drum of the delayed coke unit while it is off line in a coking cycle and having an internal bottom portion; maintaining the temperature of the bottom portion of the blowdown drum at a temperature above the dewpoint temperature of the water in the blowdown drum so that water is vaporized; removing the vaporized water from the blowdown drum; and feeding a stream exiting the bottom portion of the blowdown drum to a fractionator, which is also used for fractionating feedstock to the delayed coker unit, for separation into product streams.

Freymeyer, D.A.; Love, J.P.; Holloway, R.L.; Torres, D.L.; Brosman, G.

1993-06-29

156

Dewatering and RCRA partial closure action on solar evaporation ponds, Rocky Flats Plant, Golden, Colorado  

SciTech Connect

The Department of Energy (DOE) has prepared an Environmental Assessment (DOE/EA-0487) on its proposal to partially close five solar evaporation ponds at the Rocky Flats Plant (RFP) pursuant to the requirements of the Resource Conservation and Recovery Act (RCRA). This proposal would be known as a RCRA partial closure and would be accomplished by dewatering the ponds, where necessary, and converting any remaining sludge or evaporator concentrate to a solid wasteform (pondcrete and saltcrete). The pond sites would be stabilized to prevent erosion or other disturbance to the soil and to prevent infiltration of rain or snowmelt. The solid wasteform would be transported offsite for disposal. The five solar ponds (designated 207-A, 207-B (north, center, and south), and 207-C), are the only solar evaporation ponds that exist at the RFP. A finding of no significant impact is included.

Not Available

1991-06-01

157

Consolidation theory and its applicability to the dewatering and covering of uranium-mill tailings  

SciTech Connect

This report is a review and evaluation of soil consolidation theories applicable for evaluating settlement during dewatering and subsequent covering of uranium-mill tailings. Such theories may be used to predict both consolidation and water flow related effects in uranium-mill tailings during drainage, following sluicing into burial pits. A consolidation theory to be useful must consider the effect of time-dependent loads, nonhomogeneous soil mass, nonlinear variation of soil properties with the stress-state parameters, large strain, and saturated and unsaturated flow. Constitutive relations linking the stress-deformation-state variables with void ratio should be adopted for predicting both consolidation and fluid-flow interaction in unsaturated uranium-mill tailings.

Gates, T.E.

1982-11-01

158

The role of ionic surfactants in compression dewatering of alum sludge  

SciTech Connect

This work has experimentally investigated the characteristics of filtration followed by consolidation dewatering of an alum sludge, with especial attention to the effects of adding ionic surfactants (SDS or CTAB). The filtration and consolidation stages at a pressure of 3000 psi were discussed separately. The efficiency of filtration is enhanced in the presence of surfactant molecules; however, the cationic surfactant (CTAB) raises the consolidation rate while the anionic surfactant (SDS) retards it. A newly proposed theological model has been employed for interpreting the consolidation data. CTAB would not alter markedly the moisture distribution in the sludge, but SDS does increase markedly the amount of the tightly bound moisture by diminishing the portion occupied by pore water. The possible role of surfactants in the sludge flocs is considered. Both surfactants can be used as conditioning aids during the filtration stage. However, the applications of SDS to the consolidation stage are not encouraged.

Chu, C.P.; Lee, D.J. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Chemical Engineering; Huang, C. [National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Inst. of Environmental Engineering

1998-10-01

159

Effects of calcined aluminum salts on the advanced dewatering and solidification/stabilization of sewage sludge.  

PubMed

The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl2, Na2SO4 and CaSO4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS(0) obtained with 5% AS and 10% CaSO4 of AS by weight presented a moisture contents below 50%-60% and a compressive strength of (51.32 +/- 2.9) kPa after 5-7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry-differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO3) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill. PMID:22125919

Zhen, Guangyin; Yan, Xiaofei; Zhou, Haiyan; Chen, Hua; Zhao, Tiantao; Zhao, Youcai

2011-01-01

160

Modes of Fluid Expulsion and its Significance for Forearc Dewatering at Costa Rica Convergent Margin  

NASA Astrophysics Data System (ADS)

The expulsion of chloride-depleted fluids is characteristic for vent sites at Costa Rica continental margin. Oxygen and hydrogen isotope ratios, thermogenic methane as well as elevated heat flow demonstrate that the fluid flow is initiated by mineral dehydration in subducting sediments at about 10-12 km depth. Conspicuous differences in the geochemical composition allow a subdivision of a southern and a northern type of fluids, which may reflect differences in the input or a general south to north decrease in flow rates. Fluids of the southern type are enriched in boron and typically rise at high rates. In contrast, the northern type of fluids is strongly enriched in calcium and barium, which points to significant alteration along the flow path. Fluid venting seems to be an important dewatering process as it occurs at a huge number of mound-like structures, which are carbonate-capped in many places and comprise of mixed types of mud extrusion features, along major slope failures caused by subducting seamounts and at fault-controlled slides. Convergence related seamount subduction and subduction-erosion are the primary reasons for slope instability, resulting in large-scale deformation structures. Fluid expulsion related to seamount subduction is largely unconstrained at present. Whereas seeps are rare at the top of the uplifted sediment bulge, massive discharge of methane-rich fluids is documented by lush tubeworm communities and significant methane plumes at the scarp planes. Recent estimates reveal that up to 65 Mg of methane per year may be released at a single structure, which may prove them as important as the mound structures in terms of fluid recycling. In order to improve our current understanding of fluid recycling, to constrain long-term estimates of fluid flow, to systematize the variability of fluid geochemistry, and to fully understand the role of seamounts in the forearc it is proposed to drill several key sites of the most prominent dewatering structures within IODP (proposal 633 full).

Hensen, C.; Wallmann, K.; Ranero, C.; Rehder, G.; Brueckmann, W.; Grevemeyer, I.; Reston, T.

2005-12-01

161

Dewatering a deep gas well with a gas lift system-a case history  

SciTech Connect

A characteristic of Fusselman gas wells in the Permian Basin is that they begin to produce connate water early in the life of the well. Eventually the water entering the wellbore cannot be unloaded because the hydraulic pressure of liquid fall back becomes greater than the reservoir pressure and the well ceases to flow. At this watered out and nonflow state, considerable gas may remain in the formation. This case study deals with the development of a closed loop gas lift system designed to unload water. The gas lift system consists of: a predetermined number of gas lift valves externally mounted on mandrels and installed in the tubing string, surface processing equipment, and a gas compressor. Dewatering of the well is accomplished by injecting gas down the tubing-casing annulus and through the gas lift valves. The injection and dewatering process continues until the reservoir pressure overcomes the hydrostatic head. At this point the well will kick-off and flow. To maintain this flowing condition, a portion of the wellstream is diverted and reinjected into the well to maintain high velocities in the tubing. The high tubing flow rate lifts the water and reduces the dynamic pressure gradient in the tubing. The well in this study is currently producing in the above manner. Restoration of gas flow in this well required thirty days due to the uniqueness of the project and modifications through trial and error. Since then, the well has stabilized with a sales volume of 1,100 Mcf/D (31,500 m/sup 3//d) and gas lifts 350 barrels of water daily (55 m/sup 3//d). An injection volume of 400 Mcf/D (11,455 m/sup 3//d) maintains high tubing velocities and prevents the well from loading with water. An increase in reserves has resulted from gas lifting this nonproductive well.

Green, R.E.; Korzekwa, C.R.

1984-03-01

162

Study on the effect and mechanism of hydrothermal pretreatment of dewatered sewage sludge cake for dewaterability.  

PubMed

In China, over 17 million tons dewatered sewage sludge cake (DSSC), with about 80% water content, was generated from wastewater treatment plants in 2010. High water content is the bottleneck of sludge treatment and disposal. In this study, the combination of hydrothermal and mechanical treatments has been chosen in order to improve sludge dewaterability. Sludge thermogravimetry analysis was conducted to determine 180 degrees C as the upper-limit hydrothermal temperature. Five temperatures (60, 80, 120, 150, 180 degrees C) were chosen to study the effects of hydrothermal treatment temperature and the holding time on dewaterability. The higher the hydrothermal temperature, the better was the dewaterability character. The water contents of solid products were positively correlated with the hydrothermal holding time at predetermined temperatures in this study. Degradation of macromolecules into acidic compounds could be the reason of pH decrease of separated liquid. Destruction of zoogloe and decomposition of organic matters improved the sludge dewaterability. Sludge dewaterability experiencing hydrothermal processes in this study was negatively correlated with extracellular polymeric substance (EPS) content. With the rising temperature, sludge flocculate disaggregated to small particles generally, this could also be one of the important reasons for sludge dewaterability. Implications: High water content is the bottleneck of sludge treatment and disposal. Up to now, only a small amount of research has been conducted to determine whether the dewaterability of dewatered sewage sludge cake can be improved by hydrothermal pretreatment. The mechanism of sludge dewaterability by hydrothermal pretreatment is uncertain. In this study, a new sludge disposal method and corresponding parameters were given. The mechanism of sludge dewaterability was analyzed extensively by extracellular polymeric substances, scanning electron microscope images, element contents, and caloric values, etc. This study will be helpful for knowing about sludge hydrothermal pretreatment technology and its mechanism. PMID:24010381

Zhu, Ying; Han, Zhe; Liu, Xiuyu; Li, Jing; Liu, Feng; Feng, Suping

2013-08-01

163

Evaluation of the connector well roof dewatering method in the abatement of acidic mine drainage from the Arnot No. 2 mine, Tioga County, Pennsylvania  

SciTech Connect

Two connector wells commenced dewatering by a gravity exchange mechanism between two aquifers above and below this 255 ha mine on July 1, 1981. The source aquifer (above the mine) consisted of 2.2 ha of reclaimed strip-spoil. The dewatering system captured vertically moving waters in the spoil, glacial drift, and the Allegheny Group units above areas of acid-producing strata in the mine roof. The waters were injected into the Huntley Mountain Aquifer approximately 50 m below the mine floor. Data from drilling, testing, and monitoring program were integrated with statistical analyses to develop a hydrologic conceptual model of the mine. These analyses indicate that the mean water-table elevation in the shallow overburden units is directly related to discharge, discharge is both inversely related to concentration and directly related to pollution loadings. The two connector wells effectively dewatered the strip-spoil aquifer in less than three months. In response to operation the Huntley Mountain Aquifer displayed a potentiometric level build-up of over 26 m in observation well 25, which is located 88 m from the nearest dewatering well. Dewatering effects on portal discharge, concentration, and loading were investigated by multiple regression models. Annual equivalent groups displayed no significant differences in pre- and post-construction data. Baseflow comparison of data exhibited significant differences for discharge and some chemical parameters. Water quality deterioration occurred in both aquifers during dewatering. This resulted in source aquifer screen encrustation and effective porosity reduction in the injection zone.

Buss, D.R.

1986-01-01

164

Influence of Filter Cell Configuration and Process Parameters on the Electro-Osmotic Dewatering of Sewage Sludge  

Microsoft Academic Search

This paper shows a laboratory parametric study carried out for optimizing the electro-dewatering (EOD) of agro-industrial sludge. The sludge dry matter reached 40% w\\/w after 3 hours of EOD with current density of 80 A\\/m, against 20% w\\/w after 11 hours of mechanical compression. The electricity consumption was 0.27 kWh\\/kg of water removed. Another advantage of EOD lies on the depolluting

M. Citeau; O. Larue; E. Vorobiev

2011-01-01

165

Influence of Filter Cell Configuration and Process Parameters on the Electro-Osmotic Dewatering of Sewage Sludge  

Microsoft Academic Search

This article shows a laboratory parametric study carried out for optimizing the electro-dewatering (EOD) of agro-industrial sludge. The sludge dry matter reached 40% w\\/w after 3 hours of EOD with current density of 80 A\\/m, against 20% w\\/w after 11 hours of mechanical compression. The electricity consumption was 0.27 kWh\\/kg of water removed. Another advantage of EOD lies on the depolluting effect

M. Citeau; O. Larue; E. Vorobiev

2012-01-01

166

Gas hydrate destabilization: enhanced dewatering, benthic material turnover and large methane plumes at the Cascadia convergent margin  

Microsoft Academic Search

Mixed methane–sulfide hydrates and carbonates are exposed as a pavement at the seafloor along the crest of one of the accretionary ridges of the Cascadia convergent margin. Vent fields from which methane-charged, low-salinity fluids containing sulfide, ammonia, 4He, and isotopically light CO2 escape are associated with these exposures. They characterize a newly recognized mechanism of dewatering at convergent margins, where

E. Suess; M. E. Torres; G. Bohrmann; R. W. Collier; J. Greinert; P. Linke; G. Rehder; A. Trehu; K. Wallmann; G. Winckler; E. Zuleger

1999-01-01

167

Temperature influence of nonionic polyethylene oxide and anionic polyacrylamide on flocculation and dewatering behavior of kaolinite dispersions  

Microsoft Academic Search

Nonionic polyethylene oxide (PEO) and anionic polyacrylamide (PAM) flocculation of kaolinite dispersions has been investigated at pH 7.5 in the temperature range 20–60°C. The surface chemistry (zeta potential), particle interactions (shear yield stress), and dewatering behavior were also examined. An increase in the magnitude of zeta potential of kaolinite particles, in the absence of flocculant and at a fixed PEO and

Patience Mpofu; Jonas Addai-Mensah; John Ralston

2004-01-01

168

Mechanics of InSAR-identified bedrock subsidence associated with mine-dewatering in North-Central Nevada  

NASA Astrophysics Data System (ADS)

Interferometric Synthetic Aperture Radar, or InSAR, has proven to be an invaluable tool for ground motion studies in the geosciences. It was not until recently that InSAR has been used extensively for the delineation of aquifer system response to heavy groundwater pumping. A number of studies have demonstrated the vastly improved spatial resolution afforded by InSAR relative to traditional surveying techniques in detecting groundwater-related subsidence. Ground subsidence related to mine dewatering is a common occurrence due to the large volumes of water that are pumped in order to lower the local groundwater table to facilitate open pit and underground mining operations. Several mines located along the Carlin Trend of Central Nevada have produced InSAR identified subsidence signals of greater aerial extent and magnitude than most municipal groundwater signals. The dewatering signal at Betze-Post shows a minimum of 45.8 cm of cumulative subsidence between June 1, 1992 and September 21, 2000. Our study has created many (>50) interferograms, allowing a better understanding of how the subsidence signal evolved in response to varied pumping rates from dewatering wells. The deformation signal correlates well with the observed groundwater drawdown characteristics. However, since the spatial resolution of the InSAR is much better than that of the monitoring well locations, the complexity of the signal is better delineated. The maximum aerial extent of the subsidence feature extends as far as 20 km away from the location of the extraction wells used for dewatering. Of greatest interest is the fact that this subsidence signal exists mostly in areas of very shallow or exposed bedrock. Groundwater related bedrock subsidence of this scale is rarely, if ever, observed, and therefore, poorly understood. This study utilizes InSAR results to devise a simple, one dimensional bedrock subsidence model that utilizes easily obtained rock mass characteristics.

Katzenstein, Kurt W.

169

Prediction of chloride leaching from a non-irrigated, de-watered saline soil using the MACRO model  

Microsoft Academic Search

A pedon scale study was conducted to investigate the degree of chloride leaching from a de-watered saline soil profile in the non-irrigated wheatbelt region of south-western Australia. Within the surface 250mm of the soil profile was a dispersed layer acting as a hydraulic throttle. Soil water tensions and chloride concentrations were obtained over a two-year period over depths ranging from

P. L. Bourgault Du Coudray; D. R. Williamson; W. D. Scott

1997-01-01

170

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly progress report, July - September 1996  

SciTech Connect

The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale. The study which is in progress is being conducted at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter laboratory dewatering studies were conducted using a 4-in diameter laboratory chemical centrifuge. The baseline data provided a filter cake with about 32% moisture. Addition of 0.3 kg/t of a cationic surfactant lowered the moisture to 29%. Addition of anionic and non-ionic surfactant was not effective in reducing the filter cake moisture content. In the pilot scale studies, a comparison was conducted between the high pressure and vacuum dewatering techniques. The base line data with high pressure and vacuum filtration provided filter cakes with 23.6% and 27.8% moisture, respectively. Addition of 20 g/t of cationic flocculent provided 21% filter cake moisture using the high pressure filter. A 15% moisture filter cake was obtained using 1.5 kg/t of non-ionic surfactant. Vacuum filter provided about 23% to 25% moisture product with additional reagents. The high pressure filter processed about 3 to 4 times more solids compared to vacuum filter.

Tao, D.; Groppo, J.G.; Parekh, B.K.

1996-10-01

171

The characteristics of coincineration of dewatered sludge, waste oil and waste solvent in commercial-scale fluidized bed incinerator  

Microsoft Academic Search

A commercial-scale Fluidized Bed Incinerator (FBI), which has a capacity of 60 tons per day to treat dewatered sludge and\\u000a waste oil or solvent, was developed as one of the governmental R&D projects from 1990 to 1997. From the design, construction\\u000a and operation of the plant, the characteristics of co-combustion and appropriate operating conditions with successful fly\\u000a ash recirculation and

Jae-Hoi Gu; Woon-Ha Yeo; Yong-Chil Seo; Sang-Hoon Lee; Jea-Keun Lee

2002-01-01

172

Evaluation of hyperbaric filtration for fine coal dewatering. Tenth quarterly technical progress report, January 1, 1995--March 31, 1995  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases: Phase I, model development; Phase II, laboratory studies; and Phase III, field testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase II, and Consol Inc. in Phase III of the program. All three organizations are involved in-all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase I and II will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit. Accomplishments are discussed for all three phases of study.

Parekh, B.K.; Leonard, J.W. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research; Hogg, R. [Pennsylvania State Univ., PA (United States); Fonseca, A. [Consol, Inc. (United States)

1995-09-01

173

Estimated Fall Chinook Salmon Survival to Emergence in Dewatered Redds in a Shallow Side Channel of the Columbia River  

SciTech Connect

Fall Chinook salmon (Oncorhynchus tshawytscha) often spawn in the tailraces of large hydroelectric dams on the Columbia River. Redds built in shallow habitats downstream of these dams may be periodically dewatered due to hydropower operations prior to the emergence of fry. To determine whether fall Chinook salmon redds were successful in a shallow area subjected to periodic dewatering downstream of Wanapum Dam on the Columbia River, we installed 7 redd caps and monitored fry emergence. Large numbers of live fry were captured from the redds between March 9 and May 18, 2003. Estimated survival from egg to fry for these redds, which were all subjected to some degree of dewatering during the incubation and post-hatch intragravel rearing period, ranged from 16.1 to 63.2 percent and averaged 27.8 percent (assuming 4,500 eggs/redd). The peak emergence date ranged from April 1 to 29, with the average peak about April 14, 2003. Mean fork length of fall Chinook salmon emerging from individual redds ranged from 38.3 to 41.2 mm, and lengths of fish emerging from individual redds increased throughout the emergence period.

McMichael, Geoffrey A.; Rakowski, Cynthia L.; James, B B.; Lukas, Joe

2005-08-01

174

Membrane-Based Energy Efficient Dewatering of Microalgae in Biofuels Production and Recovery of Value Added Co-Products  

SciTech Connect

The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. We have evaluated the dewatering of Nannochloropsis sp. with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ~99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, it can be shown that an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

Bhave, Ramesh R [ORNL; Kuritz, Tanya [ORNL; Powell, Lawrence E [ORNL; Adcock, Kenneth Dale [ORNL

2012-01-01

175

Evaluation of hyperbaric filtration for fine coal dewatering. Ninth quarterly technical progress report, October 1--December 31, 1994  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20% moisture. The program consists of three phases, namely: model development; laboratory studies; and field testing. The Pennsylvania State University is leading efforts in Phase 1, the University of Kentucky in Phase 2, and Consol Inc. in Phase 3 of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase 1 and 2 will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit. Results to date from all three phases are discussed.

Parekh, B.K.; Leonard, J.W. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonesca, A. [Consol Inc., Pittsburgh, PA (United States)

1995-04-01

176

Evaluation of hyperbaric filtration for fine coal dewatering. Twelfth quarterly technical progress report, July 1, 1995--September 30, 1995  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases, namely: (1) Phase I Model Development; (2) Phase II Laboratory Studies; and (3) Phase III Field Testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase 11, and Consol Inc. in Phase III of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase I and II will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit.

Parekh, B.K.; Hogg, R.; Fonseca, A.

1996-02-01

177

Evaluation of hyperbaric filtration for fine coal dewatering. Eleventh quarterly technical progress report, April 1, 1995--June 30, 1995  

SciTech Connect

The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases, namely Phase I - Model Development, Phase II - Laboratory Studies, Phase III - Field Testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase II, and Consol Inc. in Phase III of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase I and II will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit.

Parekh, B.K.; Hogg, R.; Fonseca, A.

1995-12-01

178

An integrated approach to optimize the conditioning chemicals for enhanced sludge conditioning in a pilot-scale sludge dewatering process.  

PubMed

An integrated approach incorporating response surface methodology (RSM), grey relational analysis, and fuzzy logic analysis was developed to quantitatively evaluate the conditioning chemicals in sludge dewatering process. The polyacrylamide (PAM), ferric chloride (FeCl(3)) and calcium-based mineral powders were combined to be used as the sludge conditioners in a pilot-scale sludge dewatering process. The performance of conditioners at varied dosages was comprehensively evaluated by taking into consideration the sludge dewatering efficiency and chemical cost of conditioner. In the evaluation procedure, RSM was employed to design the experiment and to optimize the dosage of each conditioner. The grey-fuzzy logic was established to quantify the conditioning performance on the basis of grey relational coefficient generation, membership function construction, and fuzzy rule description. Based on the evaluation results, the optimal chemical composition for conditioning was determined as PAM at 4.62 g/kg DS, FeCl(3) at 55.4 g/kg DS, and mineral powders at 30.0 g/kg DS. PMID:22858481

Zhai, Lin-Feng; Sun, Min; Song, Wei; Wang, Gan

2012-07-05

179

Synthesis, characterization and application of a novel starch-based flocculant with high flocculation and dewatering properties.  

PubMed

Flocculation process is one of the most widely used techniques for water and wastewater treatment, and also for sludge dewatering. Synthesis of natural biopolymers or modification of natural biopolymers as environmentally friendly flocculants is highly desired in the field of environmental protection. In this work, a water soluble copolymer flocculant, STC-g-PDMC (starch-graft-poly (2-methacryloyloxyethyl) trimethyl ammonium chloride) was synthesized through grafting a monomer, (2-methacryloyloxyethyl) trimethyl ammonium chloride (DMC), onto starch initiated by potassium persulphate. Acetone and ethanol were used for copolymer precipitation and purification in the synthesis, which diminished the toxicity during the synthesis process. The graft copolymer was characterized using Fourier-transform infrared spectroscopy, (1)H nuclear magnetic resonance, X-ray powder diffraction, thermogravimetric analysis and elemental analysis. The prepared STC-g-PDMC exhibited a highly effective flocculation capability for kaolin suspensions compared with starch and polyacrylamide as control. The charge neutralization effect played an important role in the flocculation process at low flocculant dosages. When it was used as dewatering agent for anaerobic sludge, the conditioned sludge could be easily filtered after the dosage reached 0.696% of the dry weight of sludge. Such a graft copolymer is a promising green agent for wastewater treatment and sludge dewatering applications. PMID:23531592

Wang, Jian-Ping; Yuan, Shi-Jie; Wang, Yi; Yu, Han-Qing

2013-02-13

180

Evaluation of hyperbaric filtration for fine coal dewatering. First quarterly technical progress report, September 1, 1992--November 30, 1992  

SciTech Connect

Most of the coal presently used by the utility industry is cleaned at preparation plants employing wet processes. Water, while being the mainstay of coal washing, is also one of the least desirable components in the final product. Coarse coal (+3/4 inch) is easily dewatered to a 3--4 percent moisture level using conventional vibrating screens and centrifuges. However, the main problem of excess product moisture occurs in fine (minus 28 mesh) coal and refuse. Even though fines may constitute only about 20 percent of a contemporary cleaning plant feed, they account for two-thirds of the product surface moisture. This high surface moisture offsets many of the benefits of coal cleaning, and can easily undercut the ongoing programs on recovery of fine clean coal from refuse as well as producing an ultra-fine super clean coal fuel. Currently, most of the coal preparation plants utilize vacuum disk type technology for dewatering of the fine coal, providing dewatered product containing about 25 percent moisture. The coal industry would prefer to have a product moisture in the range of 10 to 15 percent, thereby avoiding thermal drying of coal. Hyperbaric filtration. has shown potential in lowering moisture in fine coal to about 20 percent level. This project will develop fundamental information on particle-liquid interaction during hyperbaric filtration and apply the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL, Inc., Pittsburgh, PA (United States)

1992-12-31

181

Using InSar To Determine Aquifer System Response In North Central Nevada Related To Mine Dewatering  

NASA Astrophysics Data System (ADS)

Removal of groundwater to allow development of mineral deposits is a common practice in areas where the ore body is below the water table. In some instances, land subsidence and related earth fissuring can result from such dewatering. Large groundwater withdrawals on the order of 50,000 acre-ft/yr have occurred at one mine since the early 1990's in north-central Nevada to support mining. Ground fissuring believed associated with aquifer compaction has been observed in the Pumpernickel Valley-Kelly Creek Basin of East Central Nevada. The observations were coincident with periods of groundwater withdrawal for mine dewatering. Dewatering operations within the Pumpernickel Valley-Kelly Creek Basin has been from the fractured bedrock and not in the overlying alluvium. The observed basin subsidence may provide new insights into both the hydrologic connections, and also into the deformation behavior of fractured rocks. Subsidence in fractured rock aquifers has not been reported. Several techniques have been used to study and predict land subsidence, but our focus is to use one of the recently developed space-platform-based techniques know as Interferometric Synthetic Aperture Radar (InSar). The InSar processing was done using descending data acquired from European Space Agency Satellites ERS-1 and -2 on track 213 and frame 2781. Data acquired from ERS-1 and -2 covered the period between 1992 and 2000 during which time local dewatering pumping began and recorded subsequently reached a maximum of 57,000 acre-ft/year. A total of 146 interferometric pairs were derived from the data with perpendicular baselines for each pair less than 200 meters. Both the wrapped and unwrapped results were viewed and necessary corrections made. Selected unwrapped results were stacked together producing an 8 year time series showing total amount and spatial extent of subsidence. The final results gave a maximum of 36 cm displacement of the land surface during the groundwater extraction period between 1992 and 2000. The center of the subsidence bowl has been found to be close to the Humboldt River and to the north of the center of groundwater extraction for dewatering. Additional analysis of the observed subsidence, groundwater pumping history, hydrostratigraphy and aquifer systems response are in progress.

Baffoe-Twum, E.; Bell, J. W.; Tyler, S. W.; Fischer, J. R.

2006-12-01

182

Modelling dewatering behaviour through an understanding of solids formation processes. Part I--Solids formation considerations.  

PubMed

An understanding of the mechanisms which control solids formation can provide information on the characteristics of the solids which are formed. These characteristics will in turn impact on dewatering behaviour. In this paper a model for solids formation is proposed. The first part of the model considers the hydrodynamics in the precipitation vessel, from which a reactant mixing model is developed. Spatially variant solution conditions are quantified (dynamically) using an equilibrium speciation model. These calculations are performed in conjunction with an adsorption model, accounting for equilibria involving adsorbed species. The kinetics of solids formation, including nucleation, growth and aggregation, are described empirically using spatially variant supersaturation profiles. These, together with moment transformations of the solids population balance, describe the evolution of particle sizes throughout the precipitation process. Precipitation of nickel hydroxide is explored experimentally, and models developed are fitted to the results. Comments are offered on the impact of simplifications required for computational reasons, and assumptions required due to lack of information, on the accuracy of the model. In part II of this paper, the use of model outputs in predicting filtration behaviour is explored. PMID:15935141

Dustan, A C; Cohen, B; Petrie, J G

2005-03-24

183

Applicability of industrial wastewater as carbon source for denitrification of a sludge dewatering liquor.  

PubMed

The applicability of four industrial waste streams from potato processing, canola processing and oil refining, biodiesel production (glycerol), and glycol as substitutes to methanol and ethanol in denitrification of anaerobically digested sludge dewatering liquor (centrate) was evaluated in bench-scale sequencing batch reactors. It was found that glycerol was the best substitute with the specific denitrification rate (SDNR) of 13 mg NO3-N/(g VSS x h) followed by potato processing wastewater at 12mg NO3-N/(g VSS x h). Both substrates produced faster SDNR than methanol's 10mg NO3-N/(g VSS x h); however, they were inferior to ethanol's 17 mg NO3-N/(g VSS x h). Glycol had SDNR of 8 mg NO3-N/(g VSS x h) and demonstrated a very fast acclimation rate, i.e. the response in increased denitrification rate was visible in three days following glycol addition. Canola processing and oil refining wastewater was considered an inappropriate carbon source due to a low SDNR of 5 mg NO3-N/(g VSS x h) and apparent inhibitory effect on nitrification. PMID:23837324

Chen, Jiazhong; Lee, Yoomin; Oleszkiewicz, Jan A

184

Nitrogen and phosphorus recovery from wastewater and the supernate of dewatered sludge.  

PubMed

Excessive nitrogen and phosphorus supply to freshwater negatively affects water quality and ecosystem balance through a process known as eutrophication. This can lead to increased wastewater treatment costs, a reduction in the biological diversity and recreational value of natural water bodies. Besides, algal blooms can result in loss of livestock and human health issues. Therefore, efficient and reliable nitrogen and phosphorus removal methods are required. In wastewater containing relatively high concentrations of nitrogen and phosphorus (e.g. wastewater from chemical fertilizer plant, the supernate of dewatered sludge, etc.), these elements are difficult to remove economically to reach the appropriate compliance limits by biological methods. On the other hand, both nitrogen and phosphorus are nutrients for the plants, and recently, nitrogen and phosphorus recovery by precipitation (e.g. struvite) has drawn much attention, because nitrogen and phosphorus precipitates can be utilized as a fertilizer and both phosphorus and ammonium can be simultaneously removed. Thus, this review summarized nitrogen and phosphorus recovery methods, during which nitrogen and phosphorus compounds can be used as a raw material for the fertilizer industry, including the options of struvite and hydroxyapatite formation and other feasible using options. In this article most important patents are also discussed. PMID:20653545

Wang, Dong-bo; Li, Xiao-ming; Ding, Yan; Zeng, Tian-jing; Zeng, Guang-ming

2009-11-01

185

Effects of solids concentration on activated sludge deflocculation, conditioning and dewatering.  

PubMed

Optimum conditioning of activated sludge in terms of minimum CST was shown to correspond to the complete removal of turbidity, and the increase in turbidity with shear due to e.g. pumping is therefore expected to affect conditioning. The optimum polymer dosage was directly related to the turbidity of activated sludge after two minutes shear, and was considerably lower than the dosage required for charge neutralisation. The turbidity produced by shear increased more than is proportional with solids concentration and was directly related to the apparent viscosity. It is suggested that increasing solids concentration causes increased surface erosion when network structures are broken, and this causes increases in turbidity and required polymer dosage per solids mass. For Aby activated sludge, optimum polymer dosage per solids mass increased by 52% when the solids concentration was increased from 8.2 to 13.7 g SS/l. Modelling of the effect of solids concentration predicts even higher increases in required polymer dosage for higher solids concentrations. This means that reduced thickening prior to pumping and conditioning may be desirable when the hydraulic capacity of the dewatering device is sufficient. Similar trends were observed for an anaerobically digested sludge. For this sludge, reduction of turbidity with FeCl3 reduced the polymer demand. PMID:11548014

Mikkelsen, L H; Keiding, K

2001-01-01

186

Water based demulsifier formulation and process for its use in dewatering and desalting crude hydrocarbon oils  

SciTech Connect

Oil is dehydrated and/or desalted by the influence of a dewatering and desalting formulation which can be characterized as an admixture of (i) a demulsifier preferably an alkylene oxide aklyl phenol-formaldehyde condensate such as a poly ethoxylated nonylphenol-for-maldehyde condensate and (ii) a deoiler which is usefully a polyol such as ethylene glycol or poly (ethylene glycol) of Mw ranging from 106 to 44,000 and preferably ethylene glycol. The aqueous formulation may usefully contain a cosolvent such as isopropanol. The surface active agent composition is admixed with the salt-containing oil which has been emulsified with water, and heated whereby the formulation of surface active agents aids in breaking of the emulsion and transfer of salts to the aqueous phase preferably after passage through an electric coalescer whereby a clean oil product suitable for use in refining operations is recovered with remarkably low oil carry under with the effluent water when ethylene glycol is formulated into the system as the deoiler.

Merchand, P.; Lacy, S. M.

1985-11-05

187

Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae).  

PubMed

Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake. Stable flies (Stomoxys calcitrans (L.)) and house flies (Musca domestica (L.)), represented 80 and 18% of the muscoid flies, respectively. An estimated 550 stable flies and 220 house flies per square-meter of surface area developed in the biosolid cake annually producing 450,000 stable flies and 175,000 house flies. Stable fly emergence was seasonally bimodal with a primary peak in mid-July and a secondary peak in late August. House fly emergence peaked with the first stable fly emergence peak and then declined gradually for the remainder of the year. House flies tended to emerge from the biosolid cake sooner after its deposition than did stable flies. In addition, house fly emergence was concentrated around midsummer whereas stable fly emergence began earlier in the spring and continued later into the fall. Biosolid age and temperature were the most important parameters affecting emergence for house flies and stable flies, whereas precipitation was not important for either species. This study highlights the importance of biosolid cake as a larval developmental habitat for stable flies and house flies. PMID:22493845

Doud, C W; Taylor, D B; Zurek, L

2012-03-01

188

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 3, April--June 1995  

SciTech Connect

Economical dewatering of an ultra-fine clean coal product to a 20% or lower level moisture will be an important step in successful implementation of the advanced fine coal cleaning processes. The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept (POC) scale of 1 to 2 tph. The novel surface modification technique developed at the UKCAER will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals. During this quarter, addition of reagents such as ferric ions and a novel concept of in-situ polymerization (ISP) was studied in the laboratory. Using the ISP approach with vacuum filtration provided 25% moisture filter cake compared to 65.5% moisture obtained conventionally without using the ISP. A series of dewatering tests were conducted using the Andritz hyperbaric pilot filter unit with high sulfur clean coal slurry.

Groppo, J.G.; Parekh, B.K.

1995-08-05

189

Coontail fluorite rhythmites of southern Illinois: evidence for episodic basin dewatering  

SciTech Connect

Stratiform coontail ore of the Cave-in-Rock fluorite district, southern Illinois, display conspicuous, rhythmic banded textures similar to those reported in many MVT deposits throughout the world (e.g., east Tennessee, USA; Silesian-Cracow Region, Poland; and northern Baffin Island, Canada). Banding is expressed by the rhythmic alteration of two types of layers: detrital layers of fluorite mottled with particulate gangue dolomite and quartz, and layers of clear, crystalline fluorspar. Both are now composed principally of fluorite but differ in color, fabric and outline. In the past, this rhythmic banding has generally been attributed to fine-scale replacement of a primary host rock stratification or to cyclic replacement of host carbonates by a fluid of oscillating chemistry. Detailed megascopic and microscopic studies of these ores and their carbonate host real that ore bands were not derived by fine-scale in situ limestone replacement. Detrital bands contain hydraulically transported, sorted and graded, allochthonous debris derived by dissolution and disaggregation of host limestone and overlying shale. The banded fabric thus represents a cyclic interplay of chemical and hydraulic processes active during hydrothermal ore mineralization. Coontail ore bodies evidently formed in a hydrothermal spelean system, whose laterally sinuous trace reflects localization of hydrothermal activity where feeder faults intersected relatively impermeable roof-rock shales. The banded nature of these ores testifies to the ability of Mississippi Valley-type hydrothermal solutions to both create and fill their own open spaces. Moreover, the rhythmic nature of coontail ores suggests a prolonged and pulsating mineralization best explained by episodic dewatering of the Illinois Basin.

Cowan, C.A.; Kelly, W.C.; Wilkinson, B.H.

1985-01-01

190

A new model of coal-water interaction and relevance for dewatering. Final report  

SciTech Connect

This project was concerned with developing an improved understanding of how moisture is held in coals. There is a concern that the historically held view, that capillary condensation in pores plays a significant role, could not be correct, since the coal shrinks and swells in response to moisture loss and gain. Thus there is no well-defined pore system for holding the moisture. This appears true for a range of ranks from lignite to high volatile bituminous coal. Instead, it appears that something more like classical swelling of coals in solvents is responsible. This study examined this hypothesis by various means, considering both the mixing thermodynamics of coal and water (or coal and other swelling solvents) and by examining coal`s elastic response. The conclusion is that water does indeed behave like many other swelling solvents, but is a somewhat poor swelling solvent. The structure of the water swollen coal appears to remain fairly glassy, implying that many non-covalent crosslinks remain unbroken. The water interacts with coal only at certain types of adsorption sites. This is consistent with a second historical view that polar functionality is responsible for water retention. The filling of these sites, somewhat surprisingly, appeared to involve a strong enthalpic driving force, rather than the entropic driving force that characterizes solvent swelling in other solvents. The practical importance of these results for thermal dewatering processes is that the historical view is supported. That is, that pyrolytic polar group removal is necessary. An alternative suggestion, based upon attempts to further crosslink coal, has not received support.

Suuberg, E.M.; Yun, Y.; Lilly, W.D.; Leung, K.; Gates, T.; Otake, Y.; Deevi, S.C.

1995-02-01

191

Sludge dewatering and stabilization in drying reed beds: characterization of three full-scale systems in Catalonia, Spain.  

PubMed

Optimization of sludge management can help reducing sludge handling costs in wastewater treatment plants. Sludge drying reed beds appear as a new and alternative technology which has low energy requirements, reduced operating and maintenance costs, and causes little environmental impact. The objective of this work was to evaluate the efficiency of three full-scale drying reed beds in terms of sludge dewatering, stabilization and hygienisation. Samples of influent sludge and sludge accumulated in the reed beds were analysed for pH, Electrical Conductivity, Total Solids (TS), Volatile Solids (VS), Chemical Oxygen Demand, Biochemical Oxygen Demand, nutrients (Total Kjeldahl Nitrogen (TKN) and Total Phosphorus (TP)), heavy metals and faecal bacteria indicators (Escherichiacoli and Salmonella spp.). Lixiviate samples were also collected. There was a systematic increase in the TS concentration from 1-3% in the influent to 20-30% in the beds, which fits in the range obtained with conventional dewatering technologies. Progressive organic matter removal and sludge stabilization in the beds was also observed (VS concentration decreased from 52-67% TS in the influent to 31-49% TS in the beds). Concentration of nutrients of the sludge accumulated in the beds was quite low (TKN 2-7% TS and TP 0.04-0.7% TS), and heavy metals remained below law threshold concentrations. Salmonella spp. was not detected in any of the samples, while E. coli concentration was generally lower than 460MPN/g in the sludge accumulated in the beds. The studied systems demonstrated a good efficiency for sludge dewatering and stabilization in the context of small remote wastewater treatment plants. PMID:19369066

Uggetti, Enrica; Llorens, Esther; Pedescoll, Anna; Ferrer, Ivet; Castellnou, Roger; García, Joan

2009-04-14

192

Evaluation of hyperbaric filtration for fine coal dewatering. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994  

SciTech Connect

Most of the coal presently used by the utility industry is cleaned at preparation plants employing wet processes. Water, while being the mainstay of coal washing, is also one of the least desirable components in the final product. Coarse coal (+3/4 inch) is easily dewatered to a 3-4 percent moisture level using conventional vibrating screens and centrifuges. However, the main problem of excess product moisture occurs in fine (minus 28 mesh) coal and refuse. Even though fines may constitute only about 20 percent of a contemporary cleaning plant feed, they account for two-thirds of the product surface moisture. This high surface moisture offsets many of the benefits of coal cleaning, and can easily undercut the ongoing programs on recovery of fine clean from refuse as well as producing an ultra-fine super clean coal fuel. Currently, most of the coal preparation plants utilize vacuum disk or drum filter technology for dewatering of the fine coal, providing dewatered product containing about 25 percent moisture. The coal industry would prefer to have a product moisture in the range of 10 to 15 percent. Although the desired product quality can be obtained using thermal dryer, there are problems associated with this technology such as high capital costs and a source of air pollution. In the present research project, an alternative to thermal drying, hyperbaric filtration which has shown potential in lowering moisture content in fine coal to less than 20 percent level, is being investigated in detail. The project will develop fundamental information on particle-liquid interaction during hyperbaric fiftration and apply the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.

Parekh, B.K.; Leonard, J.W. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R.; Fonseca, A.

1995-01-01

193

A new, pellet-forming fungal strain: its isolation, molecular identification, and performance for simultaneous sludge-solids reduction, flocculation, and dewatering.  

PubMed

Filamentous and nonfilamentous microorganisms can cause bulking and foaming in wastewater sludge settling and dewatering. In this research, sludge degradation and bioflocculation was studied using pellet-forming filamentous fungi isolated from municipal wastewater sludge. To understand the role of filamentous fungi in sludge settling and dewatering, the isolated fungi was inoculated with both spores and pellets (beads) into sterilized and nonsterilized sludge having different suspended-solids concentrations. Biofloc formation, sludge settling, sludge degradation, change in pH of fungal-grown medium, zeta potential, and microscopic analysis of bioflocs were performed. The suspended-solids concentration was found to decrease over 5 d of incubation because of use and biodegradation by fungal biomass. The isolated fungal strain was well adapted to forming biofloc and to interacting with natural microbial flora and exhibited low capillary-suction time for sludge dewatering. PMID:18939607

Subramanian, S Bala; Yan, Song; Tyagi, R D; Surampalli, R Y

2008-09-01

194

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 2, January 1995--March 1995  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 to March 31, 1995.

Groppo, J.G.; Parekh, B.K.

1995-05-05

195

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report, No. 4, July 1995--September 1995  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 29, 1995.

Groppo, J.G.; Parekh, B.K.

1995-11-06

196

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report, April 1996--June 1996  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from April 1 - June 30, 1996.

Tao, D.; Groppo, J.G.; Parekh, B.K.

1996-07-31

197

Technical, economic, and environmental aspects of rotating cup atomization and dewatering of coal/water slurry mixtures  

SciTech Connect

Coal/water slurry rotating cup to atomization and dewatering are examined in an integrated research effort which addresses the technical, economic, and environmental aspects of the operation. The development and current state of the art in rotary atomization are reviewed. A theoretical model of the flow of a slurry of uniform consistency in a rotating cup was developed and compared to an earlier theoretical effort. The settling behavior of highly concentrated suspensions of particles in multi-gravity fields is reviewed. A user-friendly computer model of the stratified flow of a two-phase mixture undergoing sedimentation within the cup is developed from basic theory, and supplemented by empirical data on slurry rheology. These models are used to quantitatively describe the influence of the design and operating parameters of the rotating cup system and the rheological properties of the coal/water mixture on the flow within the cup. Examinations of the predicted flow field characteristics indicate that design and operating strategies exist which would allow the rotating cup to be used to effectively atomize a coal/water fuel while establishing the conditions which make possible the extraction of the supernatant water layer. The rotating cup dewatering operation is found to be economically attractive under a broad range of conditions for utility and large industrial combustion facilities.

Marnicio, R.J.

1984-01-01

198

Gas hydrate destabilization: enhanced dewatering, benthic material turnover and large methane plumes at the Cascadia convergent margin  

NASA Astrophysics Data System (ADS)

Mixed methane-sulfide hydrates and carbonates are exposed as a pavement at the seafloor along the crest of one of the accretionary ridges of the Cascadia convergent margin. Vent fields from which methane-charged, low-salinity fluids containing sulfide, ammonia, 4He, and isotopically light CO 2 escape are associated with these exposures. They characterize a newly recognized mechanism of dewatering at convergent margins, where freshening of pore waters from hydrate destabilization at depth and free gas drives fluids upward. This process augments the convergence-generated overpressure and leads to local dewatering rates that are much higher than at other margins in the absence of hydrate. Discharge of fluids stimulates benthic oxygen consumption which is orders of magnitude higher than is normally found at comparable ocean depths. The enhanced turnover results from the oxidation of methane, hydrogen sulfide, and ammonia by vent biota. The injection of hydrate methane from the ridge generates a plume hundreds of meters high and several kilometers wide. A large fraction of the methane is oxidized within the water column and generates ? 13C anomalies of the dissolved inorganic carbon pool.

Suess, E.; Torres, M. E.; Bohrmann, G.; Collier, R. W.; Greinert, J.; Linke, P.; Rehder, G.; Trehu, A.; Wallmann, K.; Winckler, G.; Zuleger, E.

1999-06-01

199

An ultra scale-down approach to assess the impact of the choice of recombinant P. pastoris strain on dewatering performance in centrifuges.  

PubMed

Pichia pastoris is becoming a desirable host in the biopharmaceutical industry for therapeutics production. It grows on methanol to high cell densities ?100 g DCW/L and secretes foreign proteins at high titers. However, the culture conditions to reach high cell densities pose a challenge to the processability by primary recovery operations, in particular centrifugation, used for cell removal. This work aims to assess the impact of recombinant P. pastoris strain selection on centrifugal dewatering. Normally, the choice of P. pastoris recombinant strain is based on best target protein expression levels; however, it is unknown whether the choice of strain will have an impact on performance of centrifugation operation. To achieve this aim, a previously developed laboratory ultra-scale down (USD) methodology that successfully predicted centrifugal dewatering of pilot-scale disk-type machines, was used in this work. Two recombinant P. pastoris strains, namely a X-33 and a glycoengineered Pichia strain, were used to perform fermentations secreting different products. The resulting harvested fermentation culture properties were analyzed and the dewatering performances of a pilot- and a large-scale disk-type centrifuge were evaluated using the USD methodology. The choice of P. pastoris strain was found to have a considerable impact on dewatering performance, with P. pastoris X-33 strain reaching better dewatering levels than the glycoengineered strain. The USD method proved to be a useful tool to determine optimal conditions under which the large scale centrifuge needed to be operated, reducing the need for repeated pilot-scale runs during early stages of process development for therapeutic products. PMID:22641601

Lopes, Adriana G; Khan, Nadia; Liddell, John; Keshavarz-Moore, Eli

2012-07-20

200

POC-scale testing of an advanced fine coal dewatering equipment/technique: Quarterly technical progress report No. 9, October 1996--December 1996  

SciTech Connect

The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter in the laboratory dewatering studies were conducted using copper and aluminum ions showed that for the low sulfur clean coal slurry addition of 0.1 Kg/t of copper ions was effective in lowering the filter cake moisture from 29 percent to 26.3 percent. Addition of 0.3 Kg/t of aluminum ions provided filter cake with 28 percent moisture. For the high sulfur clean coal slurry 0.5 Kg/t of copper and 0.1 Kg/t of aluminum ions reduced cake moisture from 30.5 percent to 28 percent respectively. Combined addition of anionic (10 g/t) and cationic (10 g/t) flocculants was effective in providing a filter cake with 29.8 percent moisture. Addition of flocculants was not effective in centrifuge dewatering. In pilot scale screen bowl centrifuge dewatering studies it was found that the clean coal slurry feed rate of 30 gpm was optimum to the centrifuge, which provided 65 percent solids capture. Addition of anionic or cationic flocculants was not effective in lowering of filter cake moisture, which remained close to 30 percent for both clean coal slurries.

Tao, D.; Groppo, J.G.; Parekh, B.K.

1997-01-21

201

Dewatering and RCRA partial closure action on solar evaporation ponds, Rocky Flats Plant, Golden, Colorado. Environmental Assessment  

SciTech Connect

The Department of Energy (DOE) has prepared an Environmental Assessment (DOE/EA-0487) on its proposal to partially close five solar evaporation ponds at the Rocky Flats Plant (RFP) pursuant to the requirements of the Resource Conservation and Recovery Act (RCRA). This proposal would be known as a RCRA partial closure and would be accomplished by dewatering the ponds, where necessary, and converting any remaining sludge or evaporator concentrate to a solid wasteform (pondcrete and saltcrete). The pond sites would be stabilized to prevent erosion or other disturbance to the soil and to prevent infiltration of rain or snowmelt. The solid wasteform would be transported offsite for disposal. The five solar ponds (designated 207-A, 207-B (north, center, and south), and 207-C), are the only solar evaporation ponds that exist at the RFP. A finding of no significant impact is included.

Not Available

1991-06-01

202

Pilot scale single stage fine coal dewatering and briquetting process. Final technical report, September 1, 1995--August 31, 1996  

SciTech Connect

The primary goal of the ongoing ICCI coal preparation research project is to reduce ash and sulfur content in coal by using fine grinding and other coal cleaning processes. The ultrafine coal particles that result from the grinding and cleaning operations are difficult to dewater, and create problems in their storage, handling and transportation. The objective of this research is to combine the dewatering and briquetting processes of fine coal preparation into a single stage operation, thereby enhancing the economic viability of utilizing fine coal. A bitumen based emulsion, Orimulsion, has proven to be an effective hydrophobic binder, which helps not only with the briquetting process but also in the expulsion of water from the coal. Encouraging results from the use of a ram extruder briquetting device led to experimentation in the production of briquettes using a lab scale roll briquetting device. In the first quarter of this reporting year, a commercially available lab scale roll briquetting machine was employed (Komarek B-100). Further testing was conducted for the rest of the year with the use of a pilot scale model (Komarek B220-A). Briquettes were produced and evaluated by comparing results developed by adjusting various parameters of the briquetting machines and feed material. Results further substantiate previous findings that curing time dictates both moisture content and strengths of briquettes, and slower roll speeds produce more robust briquettes. A statistical model was set up to determine the optimal range of operating parameters. The statistical model generated from these results provided basic relationships between the roll speed and briquette form pressure.

Wilson, J.W. [Univ. of Missouri, Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q.; Ding, Y.

1997-05-01

203

Reassessment of the effects of construction dewatering on ground-water levels in the Cowles Unit, Indiana Dunes National Lakeshore, Indiana : Supplement to Geological Survey Water Resources Investigations 78-138  

USGS Publications Warehouse

A revised dewatering plan for the construction of a nuclear power plant at the Northern Indiana Public Service Company 's (NIPSCO) Bailly Generating Station and evidence that suggests that a change in the characteristics of the confining unit 2 in and near Cowles Bog National Landmark may exist have resulted in a reassessment of the effects of construction dewatering on ground-water levels in the Indiana Dunes National Lakeshore. Model results indicate that the revision in the dewatering plan produces water-level declines that do not differ significantly from those described previously. However, when the change in the confining unit beneath Cowles Bog is considered, simulations of the simultaneous decline of a seepage mound after sealing of the fly-ash-ponds and the second phase of construction dewatering indicate that the simulated water-level declines in the aquifer unit 1 at Cowles Bog may be below the water levels tolerated by the National Park Service after 18 months. The water levels may even decline below the tolerable levels in spite of NIPSCO 's proposed plan of artificially recharging the aquifer unit 1 near the excavation site at 400 gal/min. The magnitude of the simulated water-level declines in unit 1 within the Lakeshore, caused by pumping from the excavation, depends on the relation in time between the second phase of dewatering and the decline of the seepage mound after sealing of the fly-ash-ponds, but not on the duration of dewatering beyond 18 months. (USGS)

Gillies, Daniel C.; Lapham, Wayne W.

1980-01-01

204

Predicting spread of invasive exotic plants into de-watered reservoirs following dam removal on the Elwha River, Olympic National Park, Washington  

USGS Publications Warehouse

The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam removal, which would inhibit restoration of native vegetation, is of great concern. We focused on predicting long-distance dispersal of invasive exotic plants rather than diffusive spread because local sources of invasive species have been surveyed. We included the long-distance dispersal vectors: wind, water, birds, beavers, ungulates, and users of roads and trails. Using information about the current distribution of invasive species from two surveys, various geographic information system techniques and models, and statistical methods, we identified high-priority areas for Park staff to treat prior to dam removal, and areas of the dewatered reservoirs at risk after dam removal.

Woodward, Andrea; Torgersen, Christian; Chenoweth, Joshua; Beirne, Katherine; Acker, Steve

2011-01-01

205

Assessing the impact of large-scale dewatering on fault-controlled aquifer systems: a case study in the Acque Albule basin (Tivoli, central Italy)  

NASA Astrophysics Data System (ADS)

The development of large-scale bedrock quarry operations often requires high-volume and long-term groundwater extraction to maintain a sustainable working environment. These dewatering activities often influence groundwater levels and flow patterns regionally. In the present study, the influence of the dewatering of the travertine quarry operations near the city of Tivoli, Italy, are quantitatively investigated through an integrated analysis of field data and numerical modeling. Lowering of regional groundwater levels in the vicinity of the quarry has led to destructive land subsidence and alterations to the flow system sustaining a hot-spring area. The study employs a finite element numerical model (FEFLOW) to evaluate and quantify the impact of the extensive dewatering on fault-controlled regional groundwater flow in the Acque Albule basin. By incorporating the physical field data and historical hydrologic information, the numerical model was calibrated against three groundwater scenarios, reproducing the effects of different exploitation activities, coupled with natural changes over the course of the quarry operation. The results indicate that groundwater withdrawals by the mining industry and by "Terme di Roma" spa resulted in the cessation of flow from the primary thermal spring and a drop in the phreatic level in the area consequently affected by land subsidence.

Brunetti, Elio; Jones, Jon P.; Petitta, Marco; Rudolph, David L.

2013-03-01

206

POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report No. 5, October--December, 1995  

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74{mu}m) clean coal. Economical dewatering of an ultrafine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the the University of Kentucky Center for Applied Energy Research will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. Accomplishments for the past quarter are described.

Groppo, J.G.; Parekh, B.K.

1996-02-01

207

Effect of aging, time, and temperature on fecal coliform counts during centrifugal dewatering and role of centrate in growth inhibition.  

PubMed

Recent studies have reported significant increases in fecal coliform counts in anaerobically digested sludge soon after centrifuge dewatering. The reasons behind these increases are not yet understood. This study investigated the role of inhibitor substances on the reactivation and regrowth of sludge bacteria and the effect of storage time and temperature on their growth behavior. The study consisted of full- and laboratory-scale testing, and quantified the microbiological and chemical characteristics of sludge, cake, and centrate samples under different temperatures and aging times. Significant reactivation was not observed at the treatment plants tested. Results showed that the regrowth phenomenon is not observed for all sludges, and differences in sludge characteristics and treatment processes may play a role in determining the regrowth behavior of sludge. Centrate collected from one of the treatment plants had an inhibitory effect on the growth of fecal coliform and was four times more toxic than cake to the bacteria. Chemical analyses of the centrate identified sulfide as one of the possible inhibitory compounds. The results also showed that fecal coliform have different growth and survival behavior compared to other sludge bacteria. PMID:20112538

Gardner, Julie; Ormeci, Banu

2010-01-01

208

Effect of long-term freezing and freeze-thaw cycles on indigenous and inoculated microorganisms in dewatered blackwater.  

PubMed

Wastewater treatment in many Arctic regions is inadequate, even nonexisting. Natural freezing of wastewater in those areas may be beneficial for reduction of microorganisms. The aim of this study was to investigate the effect of long-term freezing, and repeated freezing and thawing, on indigenous coliforms, fecal streptococci, and antibiotic-resistant (AR) bacteria, and inoculated Salmonella Enteriditis and E. coli bacteriophage ?X174 in dewatered blackwater. At the end of the long-term freezing experiment (10 months), an MPN recovery study was done, including the microbial groups that had shown the largest reduction, using tryptone soy broth at incubation temperatures of 10 and 20 °C overnight for the coliforms and AR bacteria, and buffered peptone water at incubation temperature of 37 °C for 18-20 h for Salmonella. Fecal streptococci were more resistant to long-term freezing than the coliform group. Total number of AR bacteria decreased slowly but constantly over the 10-month freezing period. Salmonella rapidly decreased and were nondetectable within a week but exhibited some recovery after 10 months of freezing, whereas limited or no recovery of coliforms and AR-bacteria was detected. Bacteriophages showed limited reduction during the long-term freezing. Repeated freezing and thawing increased the reduction of all tested microbial groups markedly. PMID:23113759

Gunnarsdóttir, Ragnhildur; Müller, Karoline; Jensen, Pernille Erland; Jenssen, Petter Deinboll; Villumsen, Arne

2012-11-05

209

Bacterial polymer production using pre-treated sludge as raw material and its flocculation and dewatering potential.  

PubMed

Sterilization, alkaline-thermal and acid-thermal treatments were applied to different sludge solids concentrations (17.0; 22.4; 29.8; 37.3; 44.8 g/L, respectively) and the pre-treated sludge was used as raw material for Serratia sp.1 to produce extracellular polymeric substances (EPS). After 72 h of fermentation, total EPS of 2.3 and 3.4 g/L were produced in sterilized and alkaline-thermal treated sludge as compared to that of 1.5 g/L in acid-thermal treated sludge. Lower EPS were produced at relatively higher solids concentrations (37.3; 44.8 g/L). Broth, crude forms of capsular and slime EPS were extracted from fermented broths and used as conditioning agents by combining with 150 mg of Ca(2+)/L of kaolin suspensions. Maximum flocculation activity of 79.1% and increased dewatering by 52.2% was achieved using broth and crude capsular EPS, respectively. The results demonstrated that EPS having high flocculating capability could be produced using wastewater sludge as sole raw material. PMID:22868009

More, T T; Yan, S; Hoang, N V; Tyagi, R D; Surampalli, R Y

2012-07-03

210

Hydrolysis and acidification of dewatered sludge under mesophilic, thermophilic and extreme thermophilic conditions: Effect of pH.  

PubMed

This study investigated the effect of pH (uncontrolled, 8.0, 10.0 and 12.0) and temperature (mesophilic, thermophilic and extreme thermophilic) on hydrolysis and acidification of dewatered sludge in 7-day batch fermentation experiment. Solublization of COD, protein and carbohydrates as well as concentration and composition of VFAs were investigated. Sludge hydrolysis was enhanced with higher pH and temperature. The maximum SCOD, soluble protein and carbohydrates was observed at pH 12.0 at extreme thermophilic condition. The maximum VFAs yield was obtained at thermophilic and was 2.15 times that at mesophilic condition, but it took more time to reach the maximum. The VFAs consisted of acetic, propionic, iso-butyric, n-butyric, iso-valeric, and n-valeric acids, and acetic acid was the prevalent product in most cases except for uncontrolled pH and pH 8.0 at mesophilic condition. The methane production was as follows: pH 8.0>pH 10.0>uncontrolled (0.015)>pH 12.0; mesophilic>thermophilic>extreme thermophilic. PMID:24077155

Liu, Xiaoguang; Dong, Bin; Dai, Xiaohu

2013-08-27

211

Dewatering of the Clayton Formation during construction of the Walter F George Lock and Dam, Fort Gaines, Clay County, Georgia  

USGS Publications Warehouse

Walter F. George Lock and Dam, the largest manmade structure in the South, extends over 2llz miles across the flood plain of the Chattahoochee River at Fort Gaines, Clay County, in southwest Georgia and in Henry County, in southeast Alabama. The multipurpose dam consists of two rolled-filled earth dikes, a concrete spillway, a single-stage lock with an 88-foot lift, and a 130,000 kilowatt capacity powerhouse. The foundation of the dam at the river is constructed in the Clayton Formation, and the earth dikes are constructed on river terraces at about 150 feet above msl (mean sea level). At the damsite, the top of the Clayton Formation consists of an "earthy" limestone, which is about 35 feet thick except in the river channel, where it is 12 to 15 feet thick; a "shell" limestone, which averages about 40 feet thick; and a basal "sandy" limestone, which averages about 35 feet thick. The Providence Sand underlies the "sandy" limestone and its thickness is about 175 feet at the damsite. These formations contain water under artesian conditions. The "shell" unit of the Clayton was the principal water-bearing formation pumped during construction of the lock and dam. The large yields of the wells from concentrated areas over extended periods of time indicate that in the vicinity of the Chattahoochee River, the Clayton Formation is a productive aquifer with transmissivity ranging from 48,000 to 77,000 gpd per ft. (gallons per day per foot) and storage coefficient ranging from 2.5 x 10?3 to 2.8 x 10?5. At the spillway site, pumpage ranged from an average of 1,700 to 8,400 gpm (gallons per minute) during the period April 1957 to July 1959; at the powerhouse site, pumpage ranged from 1,600 to 5,000 gpm during the period October 1957 to September 1961; and at the lock site, pumpage ranged from 4,000 to 5,000 gpm during the period July 1960 through December 1961. The large yields represent a source of large quantities of ground water available for industrial and other uses in an area readily accessihle by barge from the Gulf of Mexico to Columbus, Ga. During dewatering, the potentiometric surface was lowered from a pre-pumping altitude of about 115 to 120 feet above msl to a minimum altitude of about 40 feet above msl, or near the bottom of the "shell" limestone. The stage of the Chattahoochee River ranged from about 20 to 60 feet above the potentiometric surface at the dewatering sites. The Chattahoochee River seemingly is recharging the Clayton Formation near the damsite, possibly through large solution cavities such as were observed during construction of the spillway site at the river. Furthermore, a "honeycombed" network of large solution holes caused the collapse of a section of "earthy" limestone near the powerhouse site. Some underground leakage is expected to occur at the damsite because of the cavernous condition of the limestone, particularly on the Alabama side of the river.

Stewart, J. W.

1973-01-01

212

Characteristics of slag, fly ash and deposited particles during melting of dewatered sewage sludge in a pilot plant.  

PubMed

This study examines slag, fly ash, and deposited particles during melting of dewatered sewage sludge in a pilot plant. In addition, the chemical composition of particles in flue gas was simulated using a thermodynamics program, namely FACTSage 5.2. The results showed that the main components of slag were Al, Fe, Ca, P and Si; the minor components were Na, K, Mg, Cu, and Zn. The main chemical compound of slag was Ca4(Mg,Fe)5(PO4)6. For fly ash particles, heavy metals with the highest concentrations were in the order of Zn and As, Pb, Cu, and Cd, respectively. For non-heavy metals, Al, Fe and P were also found in significant amounts. The majority of deposited particles were composed of elements of Zn, P, S, Na, Fe, Al, Si, and Ca and such chemical compounds as Zn3(PO4)2, AlPO4, FePO4 and Fe(OH)3 while the minority consisted of elements of As, Cu, and Pb. Moreover, the compositions of deposited particles in each chamber differed due to different flue gas temperatures inside. In the secondary chamber at 760 degrees C, the amounts of Fe and Al were higher than Zn, whereas, in the other chambers (600-400 degrees C), the amount of Zn was higher. In other words, at the lower temperature the deposition of Zn was higher than the deposition of Fe and Al. In the water cooling section, volatile elements (i.e. Zn, As, Cu, Pb) were found in the highest concentrations due to a big difference in temperature between the wall surface and flue gas. From the simulation results, most of the elements in the gas phase were found to be chloride compounds, whereas those in the solid phase were in the form of oxide, sulfate, and phosphate compounds. PMID:16198048

Kanchanapiya, Premrudee; Sakano, Takeo; Kanaoka, Chikao; Mikuni, Tokuyoshi; Ninomiya, Yoshihiko; Zhang, Lian; Masui, Megumi; Masami, Furuuchi

2005-09-27

213

Characterization of controlled low-strength material obtained from dewatered sludge and refuse incineration bottom ash: Mechanical and microstructural perspectives.  

PubMed

Potential reuse of dewatered sludge (DS) and municipal solid waste incineration (MSWI) bottom ash as components to develop controlled low-strength material (CLSM) was explored. The effects of DS:MSWI bottom ash:calcium sulfoaluminate (CS¯A) cement ratio and thermal treatment of MSWI bottom ash at 900 °C on the mechanical and microstructural properties of CLSM were intensively studied to optimize the process. Results showed DS and MSWI bottom ash could be utilized for making CLSM. The CLSM prepared with milled MSWI bottom ash gave higher unconfined compressive strength (UCS) of 2.0-6.2 MPa following 1 year of curing at 1.0:0.1:0.9 ? DS:MSWI bottom ash:CS¯A ? 1.0:0.8:0.2. However, the corresponding strengths for CLSM containing thermally treated MSWI bottom ash ranged from 0.7 to 4.6 MPa, decreasing 26-65%. The microstructural analysis by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), as well as scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectroscopy (EDS) revealed that ettringite (C3A·3CS¯·H32, or AFt) crystals were the most important strength-producing constituents which grew into and filled the CLSM matrix pores. Milled MSWI bottom ash addition favored the formation of highly crystalline AFt phases and accordingly enhanced compressive strengths of CLSM specimens. In contrast, thermal treatment at 900 °C produced new phases such as gehlenite (Ca2Al2SiO7) and hydroxylapatite (Ca5(PO4)3(OH)), which deteriorated the pozzolanic activity of bottom ash and caused the strengths to decrease. Leaching tests evidenced that leachable substances from CLSM samples exhibited negligible health and environmental risks. The results of this study suggested that MSWI bottom ash can be effectively recycled together with DS in developing CLSM mixtures with restricted use of CS¯A cement. PMID:23933484

Zhen, Guangyin; Lu, Xueqin; Zhao, Youcai; Niu, Jing; Chai, Xiaoli; Su, Lianghu; Li, Yu-You; Liu, Yuan; Du, Jingru; Hojo, Toshimasa; Hu, Yong

2013-08-07

214

Prediction of chloride leaching from a non-irrigated, de-watered saline soil using the MACRO model  

NASA Astrophysics Data System (ADS)

A pedon scale study was conducted to investigate the degree of chloride leaching from a de-watered saline soil profile in the non-irrigated wheatbelt region of south-western Australia. Within the surface 250mm of the soil profile was a dispersed layer acting as a hydraulic throttle. Soil water tensions and chloride concentrations were obtained over a two-year period over depths ranging from 0.2m to 1.5m. In the first year the soil surface remained untouched. In the second year, the throttle layer was fractured by ripping to a depth of 250mm. Rainfall, runoff and potential evaporation were also measured at the site. These data were used to calibrate and run the MACRO solute transport model using three surface treatment management scenarios: I. the soil surface remains unchanged (`Do nothing'); II. the soil surface is continually ripped; III. the soil surface is ripped followed by surface scaling. The time period required, effectively, to leach the chloride from the profile, to a depth of 1.5m, was predicted. Effective leaching would take at least 400 years and possibly in excess of 200,000 years for Treatment I, 5 years for Treatment II and 90 years for Treatment III. Macropores that were observed within the sub-surface soil profile played no significant role in the leaching of the chloride. However, the rip fractures were treated as macropores by the MACRO model and as such allowed greater infiltration of water that resulted in the mobilisation of chloride within the rest of the soil profile.

Bourgault Du Coudray, P. L.; Williamson, D. R.; Scott, W. D.

215

Addition of polyaluminiumchloride (PACl) to waste activated sludge to mitigate the negative effects of its sticky phase in dewatering-drying operations.  

PubMed

This paper presents a new application of polyaluminiumchloride (PACl) as a conditioner for waste activated sludge prior its dewatering and drying. It is demonstrated at lab scale with a shear test-based protocol that a dose ranging from 50 to 150 g PACl/kg MLSS (mixed liquor suspended solids) mitigates the stickiness of partially dried sludge with a dry solids content between 25 and 60 %DS (dry solids). E.g., at a solids dryness of 46% DS the shear stress required to have the pre-consolidated sludge slip over a steel surface is reduced with 35%. The salient feature of PACl is further supported by torque data from a full scale decanter centrifuge used to dewater waste sludge. The maximal torque developed by the screw conveyor inside the decanter centrifuge is substantially reduced with 20% in the case the sludge feed is conditioned with PACl. The beneficial effect of waste sludge conditioning with PACl is proposed to be the result of the bound water associated with the aluminium polymers in PACl solutions which act as a type of lubrication for the intrinsically sticky sludge solids during the course of drying. It can be anticipated that PACl addition to waste sludge will become a technically feasible and very effective method to avoid worldwide fouling problems in direct sludge dryers, and to reduce torque issues in indirect sludge dryers as well as in sludge decanter centrifuges. PMID:23726696

Peeters, Bart; Dewil, Raf; Vernimmen, Luc; Van den Bogaert, Benno; Smets, Ilse Y

2013-04-20

216

Dewatering of Slimes.  

National Technical Information Service (NTIS)

Slimes, of the type treated according to the process of the invention, consist of aqueous suspensions of ultrafine solid materials. Due to the colloidal nature of the suspensions, separation of the solids therefrom is generally very difficult. Disposal of...

A. G. Smelley R. W. Montgomery B. J. Hamner

1978-01-01

217

Optimization of volatile fatty acid production with co-substrate of food wastes and dewatered excess sludge using response surface methodology.  

PubMed

Central-composite design (CCD) and response surface methodology (RSM) were used to optimize the parameters of volatile fatty acid (VFA) production from food wastes and dewatered excess sludge in a semi-continuous process. The effects of four variables (food wastes composition in the co-substrate of food wastes and excess sludge, hydraulic retention time (HRT), organic loading rate (OLR), and pH) on acidogenesis were evaluated individually and interactively. The optimum condition derived via RSM was food wastes composition, 88.03%; HRT, 8.92 days; OLR, 8.31 g VSS/ld; and pH 6.99. The experimental VFA concentration was 29,099 mg/l under this optimum condition, which was well in agreement with the predicted value of 28,000 mg/l. PMID:20303262

Hong, Chen; Haiyun, Wu

2010-03-19

218

Dewatering, stick-slip, dilatancy and development of broken formation in the Paleogene Shimanto group - a case study from Yakushima, SW Japan  

NASA Astrophysics Data System (ADS)

We investigated internal structures of broken formations/mélanges developed in Paleogene sedimentary rocks of the Southern Shimanto belt in Yakushima island, Southwest Japan, to understand the development processes. Unlike mélanges with bulky exotic blocks in Cretaceous Northern Shimanto belt, that often accompany pseudotachylites, mélanges and broken formations in Yakushima exhibit rootless flow folds and evidence for deformation under high pore pressure, and are closely connected to distributions of clastic dikes. Mud injection was also reported from this area. From cross-cutting relationship observed in Yaksuhima, following deformation history will be suggested: fold inception, deposition of sedimentary mélanges (broken formations), clastic dike intrusion, formation of duplexes and tectonic mélanges (broken formations). Dewatered sediments may have strengthened the sedimentary rocks, then stick-slip started to form duplexes and mélanges. The presence of rootless folds of lenticular sandstones in the broken formation suggests dilatant deformation took place during shear.

Anma, R.

2011-12-01

219

Western oil-shale development: a technology assessment. Volume 5: an investigation of dewatering for the modified in-situ retorting process, Piceance Creek Basin, Colorado  

SciTech Connect

The C-a and the C-b tracts in the Piceance Creek Basin are potential sites for the development of oil shale by the modified in-situ retorting (MIS) process. Proposed development plans for these tracts require the disturbance of over three billion m/sup 3/ of oil shale to a depth of about 400 m (1312 ft) or more below ground level. The study investigates the nature and impacts of dewatering and reinvasion that are likely to accompany the MIS process. The purpose is to extend earlier investigations through more refined mathematical analysis. Physical phenomena not adequately covered in previous studies, particularly the desaturation process, are investigated. The present study also seeks to identify, through a parametric approach, the key variables that are required to characterize systems such as those at the C-a and C-b tracts.

Not Available

1982-01-01

220

Effects of seepage from fly-ash settling ponds and construction dewatering on ground-water levels in the Cowles unit, Indiana Dunes National Lakeshore, Indiana  

USGS Publications Warehouse

Part of the Indiana Dunes National Lakeshore shares a common boundary with the Northern Indiana Public Service Company (NIPSCO). This area is underlain by unconsolidated deposits approximately 180 feet thick. NIPSCO accumulates fly ash from the burning of coal in electric-power generating units in settling ponds. Seepage from the ponds has raised ground-water levels above natural levels approximately 15 feet under the ponds and more than 10 feet within the Lakeshore. NIPSCO is presently (1977) constructing a nuclear powerplant, and construction activities include pumping ground water to dewater the construction site. The company has installed a slurry wall around the site to prevent lowering of ground-water levels within the Lakeshore. Plans call for continuous pumping through at least December 1979. A multilayered digital flow model was constructed to simulate the ground-water system. The model was used to demonstrate the effects of seepage from the fly-ash ponds on ground-water levels. Also, the model indicated a decline of 3 feet or less in the upper sand unit and 5 feet or less in the lower sand unit within the Lakeshore. (Woodard-USGS).

Meyer, William R.; Tucci, Patrick

1979-01-01

221

Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering.  

PubMed

Wastewater treatment plants often face the problems of sludge settling mainly due to sludge bulking. Generally, synthetic organic polymer and/or inorganic coagulants (ferric chloride, alum and quick lime) are used for sludge settling. These chemicals are very expensive and further pollute the environment. Whereas, the bioflocculants are environment friendly and may be used to flocculate the sludge. Extracellular polymeric substances (EPS) produced by sludge microorganisms play a definite role in sludge flocculation. In this study, 25 EPS producing strains were isolated from municipal wastewater treatment plant. Microorganisms were selected based on EPS production properties on solid agar medium. Three types of EPS (slime, capsular and bacterial broth mixture of both slime and capsular) were harvested and their characteristics were studied. EPS concentration (dry weight), viscosity and their charge (using a Zetaphoremeter) were also measured. Bioflocculability of obtained EPS was evaluated by measuring the kaolin clay flocculation activity. Six bacterial strains (BS2, BS8, BS9, BS11, BS15 and BS25) were selected based on the kaolin clay flocculation. The slime EPS was better for bioflocculation than capsular EPS and bacterial broth. Therefore, extracted slime EPS (partially purified) from six bacterial strains was studied in terms of sludge settling [sludge volume index (SVI)] and dewatering [capillary suction time (CST)]. Biopolymers produced by individual strains substantially improved dewaterability. The extracted slime EPS from six different strains were partially characterized. PMID:20122709

Bala Subramanian, S; Yan, S; Tyagi, R D; Surampalli, R Y

2010-01-07

222

Effects of Fe(II) and Fe(III) on the single-stage deammonification process treating high-strength reject water from sludge dewatering.  

PubMed

Iron (Fe) is often encountered in wastewaters. This study investigated the effects of iron on the single-stage deammonification process treating reject water from sludge dewatering. When Fe(2+) and Fe(3+) concentrations in the influent were below 1.3mg/L and 0.4 mg/L, Fe(2+) incorporation was found to be linearly correlated with NH(4)(+)-N removal. However, the excess Fe(2+) and Fe(3+) drastically deteriorated the deammonification performance. Both of the reactor performance and Fluorescence In Situ Hybridization results suggested higher sensitivity of autotrophic bacteria to iron than heterotrophs, the sequence of which was assessed to anammox bacteria>aerobic ammonium oxidizers>hetetrophic denitrifiers. With the excess existence of iron, extracellular substances were largely released by bacterial cells, which were the likely sites for iron uptake by scanning electron microscope-energy dispersive X-ray analysis. The information provided here would be useful to facilitate the application of deammonification process in the treatment of wastewater including metal iron. PMID:22483570

Liu, Sitong; Horn, Harald

2011-12-27

223

POC-scale testing of an advanced fine coal dewatering equipment/technique: Quarterly technical progress report,January--March 1997  

SciTech Connect

Laboratory centrifugal dewatering tests were conducted to study the effects of anionic and cationic flocculants on filtration of PMCC compliance (low sulfur) and non-compliance (high sulfur) ultrafine coal slurry. The results obtained with compliance coal indicated that use of 30 g/t anionic flocculant reduced filter cake moisture from 32. 3 to 29.0 percent and increased solids recovery by two absolute percentage points. Use of cationic flocculant had no effects on solids recovery but lowered cake moisture to 27 percent at a dosage of 15 g/t. With the non-compliance coal slurry addition of 15 g/t anionic flocculant lowered cake moisture from 30 to 28.5 percent with marginal effects on solids recovery; addition of cationic flocculant reduced cake moisture by one absolute percentage point. Both flocculants showed marginal effects on solids recovery. Laboratory vacuum filter leaf filtration studies showed that use of flocculants considerably increased filtration kinetics. For example, addition of 15 g/t anionic flocculant to the compliance coal slurry increased filtration kinetics by 10 times and addition of 15 g/t.

Tao, D.; Grappo, J.G.; Parekh, B.K.

1997-05-07

224

Present Technology of Sludge Dewatering.  

National Technical Information Service (NTIS)

A review of problems confronted in disposing sludges from water purification and municipal wastewater treatment plants is presented. The quantities and characteristics of these sludges that must be dealt with are enumerated. Each of a variety of biologica...

J. E. Smith

1970-01-01

225

Clastic-hosted stratiform, vein/breccia and disseminated Zn-Pb-Ag deposits of the northwestern Brooks Range, AK: Are they different expressions of dewatering of the same source basin  

SciTech Connect

Sphalerite and galena, with significant silver occur in 3 distinct types of mineralization hosted in Upper Devonian and Carboniferous clastic rocks of the northwestern Brooks Range. The best known are Zn-Pb-Ag massive sulfide deposits with variable pyrite, barite, and hydrothermal silifica hosted in Mississippian (to Pennsylvanian ) black siliceous shale and chert, and similar to shale-hosted Pb-Zn massive sulfide deposits worldwide. Zn-Pb-Ag breccias and veins are hosted in Upper Devonian to Lower Mississippian fine-grained quartzites and siltstone which stratigraphically underlie the massive sulfide-hosting units. The breccia-vein and disseminated occurrences are co-extensive with the rocks that host massive sulfide deposits, and with the western part of the Endicott Group clastic basin. Pb isotopic ratios of galena from all the deposits are remarkably uniform, and suggest a single Pb source. The authors genetic model suggests that all types are the result of dewatering of a single clastic source basin. Different mineralization styles are probably due to variable depths of emplacement (at or below the seafloor), thermal variations related to extensional thinning of the crust, and hydrologic flow out of the basin controlled by extensional thinning of the crust, and hydrologic flow out of the basin controlled by extensional faulting and permeability variations in local stratigraphy. The most likely sources for Zn and Pb are clay minerals within the lowermost (Hunt Fork Shale) portions of the western Endicott Group.

Schmidt, J.M. (Geological Survey, Anchorage, AK (United States)); Werdon, M.B. (Univ. of Alaska, Fairbanks, AK (United States). Dept. of Geology)

1993-04-01

226

Dewatering of solid residues of carbonaceous materials  

SciTech Connect

A process is claimed for removal of water from a mixture of water and certain solid residues of carbonaceous material, such as a coal charwater slurry. The process comprises: mixing the slurry with an acid, preferably hydrochloric acid, a surfactant, preferably water immiscible such as lecithin, and an organic compound such as a liquid hydrocarbon, e.g., mineral spirits; causing the char to agglomerate, and thereby facilitating separation of the char from the mixture, as by screening; and filtering or centrifuging.

Campen, D.C.; Crosby, A.C.

1982-04-06

227

ACOUSTIC FORMING FOR ENHANCED DEWATERING AND FORMATION  

SciTech Connect

The next generation of forming elements based on acoustic excitation to increase drainage and enhances formation both with on-line control and profiling capabilities has been investigated in this project. The system can be designed and optimized based on the fundamental experimental and computational analysis and investigation of acoustic waves in a fiber suspension flow and interaction with the forming wire.

Cyrus K Aidun

2007-11-30

228

A Mechanism for Ash Assisted Sludge Dewatering.  

National Technical Information Service (NTIS)

The ability of various additives to improve the dewaterability of activated sludge was determined and the surface properties of additives characterized in order to arrive at a mechanism for ash conditioning of activated sludge. The primary additives inves...

F. J. Micale

1976-01-01

229

A MECHANISM FOR ASH ASSISTED SLUDGE DEWATERING  

EPA Science Inventory

The ability of various additives to improve the dewaterability of activated sludge was determined and the surface properties of additives characterized in order to arrive at a mechanism for ash conditioning of activated sludge. The primary additives investigated were fly ash and ...

230

Dewatering concepts at Zambian Copperbelt Mines  

Microsoft Academic Search

During the financial year 1992\\/93, Zambian Consolidated Copper Mines Ltd (ZCCM) Ltd pumped a total of 263 million tonnes of\\u000a water from its various mining operations. During the same period the Company produced 23 million tonnes of ore, giving a water\\u000a to ore ratio of 11.4 tonnes of water per tonne of ore produced. Hydrostatic pressures interesected in underground boreholes

E. J. Naish

1992-01-01

231

Sewage sludge dewatering using flowing liquid metals  

DOEpatents

A method and apparatus for reducing the moisture content of a moist sewage sludge having a moisture content of about 50% to 80% and formed of small cellular micro-organism bodies having internally confined water is provided. A hot liquid metal is circulated in a circulation loop and the moist sewage sludge is injected in the circulation loop under conditions of temperature and pressure such that the confined water vaporizes and ruptures the cellular bodies. The vapor produced, the dried sludge, and the liquid metal are then separated. Preferably, the moist sewage sludge is injected into the hot liquid metal adjacent the upstream side of a venturi which serves to thoroughly mix the hot liquid metal and the moist sewage sludge. The venturi and the drying zone after the venturi are preferably vertically oriented. The dried sewage sludge recovered is available as a fuel and is preferably used for heating the hot liquid metal.

Carlson, Larry W. (Oswego, IL)

1986-01-01

232

DEWATERING OF DILUTE AQUEOUS HAZARDOUS WASTES USING REVERSIBLE GEL ABSORPTION  

EPA Science Inventory

The feasiability of using crosslinked gels in a reversible process for extracting pure water from aqueous waste solutions has been investigated. It has potential for concentrating waste streams that contain hazardous chemicals. Near critical gels have been developed which swell a...

233

Relationship of shale dewatering and smectite dehydration to undercompaction occurrence  

SciTech Connect

The cause(s) of abnormal fluid pressures in sedimentary basins are not clearly understood. One step in determining the mechanism(s) of abnormal pressure generation in sedimentary basins is to develop an understanding of the relationship among undercompacted shale, abnormal pressure, and temperature. Our research focused on understanding undercompaction and how it related to smectite-illite conversion. A series of carefully designed experiments were used to help clarify and evaluate the relationship of smectite-illite transformation to undercompaction.

Leftwich, J.T. Jr.

1996-12-01

234

Dewatering of organics by pervaporation with silica membranes  

Microsoft Academic Search

A major drawback of polymeric membranes for pervaporation is their limited solvent and temperature stability. This means that for several potential applications the membrane lifetime in combination with a relatively low performance is the limiting factor for introducing them into the market. More stable membranes are therefore needed. ECN has developed a new tubular microporous membrane based on hydrophilic silica

H. M. van Veen; Y. C. van Delft; C. W. R. Engelen; P. P. A. C. Pex

2001-01-01

235

INCREASE OF INDICATOR ORGANISMS FOLLOWING ANAEROBIC DIGESTION AND CENTRIFUGE DEWATERING.  

EPA Science Inventory

The Water Environment Research Foundation (WERF) recently published a report titled ?Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges?. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bac...

236

The ABCs of pump selection for mine dewatering  

SciTech Connect

Choosing the right type of pump for removing water from mine operations can provide significant benefits in overall performance and cost of operation. The article describes the types of pump most commonly used: vertical turbine pumps, electric and hydraulic submersible pumps, horizontal multistage centrifugal pumps and horizontal single-stage centrifugal pumps. It gives points to consider when selecting a suitable pump, including solids handling capacity and acid content, portability, automatic operation, easy maintenance and parts availability. 1 photo.

Morgan, S.E.

2008-10-15

237

Ultrafine coal single stage dewatering and briquetting process.  

National Technical Information Service (NTIS)

It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultr...

J. W. Wilson R. Q. Honaker

1995-01-01

238

Sewage Sludge ElectroDewatering Treatment—A Review  

Microsoft Academic Search

Purification of municipal wastewater generates huge amounts of sewage sludge, which contains large quantities of water, biomass, and extracellular polymeric substances. It is widely known that sewage sludge usually has a poor dewaterability. A large amount of water in sludge directly translates into high transport and handling costs; therefore, sludge treatment and disposal usually requires over 50% of the operation

Pham-Anh Tuan; Sillanpää Mika; Isosaari Pirjo

2012-01-01

239

Pressate from Peat Dewatering as a Substrate for Bacterial Growth  

PubMed Central

This study considered the possibility of using water expressed during the drying of fuel-grade peat as a substrate for microbial growth. Highly humified peat pressed for 2.5 min at 1.96 MPa produced water with a chemical oxygen demand of 690 mg/liter. Several biological compounds could be produced by using the organic matter in expressed peat water as a substrate. These included polymers such as chitosan, contained in the cell wall of Rhizopus arrhizus, and two extracellular polysaccharides, xanthan gum and pullulan, produced by Xanthomonas campestris and Aureobasidium pullulans, respectively. A very effective surfactant was produced by Bacillus subtilis grown in the expressed water. Small additions of nutrients to the peat pressate were necessary to obtain substantial yields of products. The addition of peptone, yeast extract, and glucose improved production of the various compounds. Biological treatment improved the quality of the expressed water to the extent that in an industrial process it could be returned to the environment.

Mulligan, Catherine N.; Cooper, David G.

1985-01-01

240

A study on the dewatering of industrial waste sludge by fry-drying technology  

Microsoft Academic Search

In sludge treatment, drying sludge using typical technology with high water content to a water content of approximately 10% is always difficult because of adhesive characteristics of sludge. Many methods have been applied, including direct and indirect heat drying, but these approaches of reducing water content to below 40% after drying is very inefficient in energy utilization of drying sludge.

Tae-In Ohm; Jong-Seong Chae; Jeong-Eun Kim; Hee-kyum Kim; Seung-Hyun Moon

2009-01-01

241

A study on the dewatering of industrial waste sludge by fry-drying technology.  

PubMed

In sludge treatment, drying sludge using typical technology with high water content to a water content of approximately 10% is always difficult because of adhesive characteristics of sludge. Many methods have been applied, including direct and indirect heat drying, but these approaches of reducing water content to below 40% after drying is very inefficient in energy utilization of drying sludge. In this study, fry-drying technology with a high heat transfer coefficient of approximately 500 W/m(2) degrees C was used to dry industrial wastewater sludge. Also waste oil was used in the fry-drying process, and because the oil's boiling point is between 240 and 340 degrees C and the specific heat is approximately 60% of that of water. In the fry-drying system, the sludge is input by molding it into a designated form after heating the waste oil at temperatures between 120 and 170 degrees C. At these temperatures, the heated oil rapidly evaporates the water contained in the sludge, leaving the oil itself. After approximately 10 min, the water content of the sludge was less than 10%, and its heating value surpassed 5300 kcal/kg. Indeed, this makes the organic sludge appropriate for use as a solid fuel. The wastewater sludge used in this study was the designated waste discharged from chemical, leather and plating plants. These samples varied in characteristics, especially with regard to heavy metal concentration. After drying the three kinds of wastewater sludge at oil temperatures 160 degrees C for 10 min, it was found that the water content in the sludge from the chemical, leather, and plating plants reduced from 80.0 to 5.5%, 81.6 to 1.0%, and 65.4 to 0.8%, respectively. Furthermore, the heat values of the sludge from the chemical, leather, and plating plants prior to fry-drying were 217, 264, and 428 kcal/kg, respectively. After drying, these values of sludge increased to 5317, 5983 and 6031 kcal/kg, respectively. The heavy metals detected in the sludge after drying were aluminum, lead, zinc, mercury, and cadmium. Most importantly, if the dried sludge is used as a solid fuel, these heavy metals can be collected from the dust collector after combustion. PMID:19272710

Ohm, Tae-In; Chae, Jong-Seong; Kim, Jeong-Eun; Kim, Hee-Kyum; Moon, Seung-Hyun

2009-02-20

242

Combined dewatering and liquid phase hydrogenolysis of raw peat using carbon monoxide  

SciTech Connect

There is provided a process for the hydrogenolysis of raw humid peat by treating untreated peat as obtained from the bog with carbon monoxide at a temperature of from 350 degree to 373 degree C and under a pressure up to 35 mpa and recovering bitumen-like compounds from the non-aqueous phase.

Cavalier, J.; Chornet, E.

1982-05-04

243

Method and apparatus for de-watering biomass materials in a compression drying process  

DOEpatents

A method and apparatus for more effectively squeezing moisture from wood chips and/or other "green" biomass materials. A press comprising a generally closed chamber having a laterally movable base at the lower end thereof, and a piston or ram conforming in shape to the cross-section of the chamber is adapted to periodically receive a charge of biomass material to be dehydrated. The ram is forced against the biomass material with suffcient force to compress the biomass and to crush the matrix in which moisture is contained within the material with the face of the ram being configured to cause a preferential flow of moisture from the center of the mass outwardly to the grooved walls of the chamber. Thus, the moisture is effectively squeezed from the biomass and flows through the grooves formed in the walls of the chamber to a collecting receptacle and is not drawn back into the mass by capillary action when the force is removed from the ram.

Haygreen, John G. (Roseville, MN)

1986-01-01

244

Dewatering of Brewer's Spent Grain Using a Membrane Filter Press: A Pilot Plant Study  

Microsoft Academic Search

In Portugal, brewer's spent grain (BSG) is produced in huge quantities as a by?product with moisture of 70–80%. Under environmental conditions, because of its high moisture and fermentable sugar content, BSG becomes an environmental problem after a short time (7–10 days). Thus, it must be transported to animal farms to be consumed within that period of time. In this paper,

M. L. F. Gameiro; P. F. M. Correia; J. M. R. de Carvalho

2004-01-01

245

Increases in fecal coliform bacteria resulting from centrifugal dewatering of digested biosolids  

Microsoft Academic Search

In many countries, the classification of biosolids for disposal purposes can be based, in part, on fecal coliform levels, with alternative criteria also available based on the stabilization process used, such as anaerobic digestion. The assumption that these alternative criteria provide equivalent protection may be flawed. This paper demonstrates that fecal coliform levels determined after digestion do not always indicate

Yinan Qi; Steven K. Dentel; Diane S. Herson

2007-01-01

246

Relationship of shale dewatering and smectite dehydration to undercompaction occurrence. Final report, October 1995--September 1996  

SciTech Connect

The cause(s) of abnormal fluid pressures in sedimentary basins are not clearly understood. One step in determining the mechanism(s) of abnormal pressure generation in sedimentary basins is to develop and understanding of the relationship among undercompacted shale, abnormal pressure, and temperature. The research focused on understanding undercompaction and how it related to smectite-illite conversion. A series of carefully designed experiments were used to help clarify and evaluate the relationship of smectite-illite transformation to undercompaction. Work was performed at the East Flour Bluff oil field, Nueces County, TX and the Ann Mag oil field, south TX.

Leftwich, J.T. Jr.

1996-12-01

247

Assessment of Multimodal Transport of Baled Poultry Litter and Dewatered Biosolids from Northwest Arkansas.  

National Technical Information Service (NTIS)

Stakeholders in the Ozarks region have expressed concern over the degradation of surface water, with the poultry industry and municipal wastewater plants cited as possible contributors. Exporting poultry litter and municipal biosolids is a possible approa...

H. L. Goodwin

2007-01-01

248

Sludge dewatering by electrokinetic technique: effect of processing time and potential gradient  

Microsoft Academic Search

A sludge cake (87.8% of moisture content) from a wastewater treatment plant was used to investigate the effects of processing time and potential gradient on the water removal by an electrokinetic (EK) process. A potential gradient ranging from 2.5 to 5.0 V\\/cm was applied to induce the movement of bound water within the sludge specimen for a time period of

Ching Yuan; Chih-huang Weng

2003-01-01

249

Dewatering of liwuid radioactive wastes in thin-film rotary evaporators  

Microsoft Academic Search

A sizable amount of liquid radioactive waste of different levels of radioactivity is formed during the operation of an atomic power plant and during reprocessing of spent nuclear fuel. Current concepts for handling such wastes require reliable isolation of them from the biosphere. At present, bituminization and cementation for medium- and low-level liquid radioactive waste and vitrification for high- and

A. S. Nikiforov; V. I. Vlasov; V. I. Davydov; P. G. Dobrygin; A. I. Kachurin; O. A. Krivyakov; D. A. Kukiev; A. S. Polyakov; V. F. Savelev; S. N. Filippov

1989-01-01

250

Proof of concept and performance optimization of high gravity batch type centrifuge for dewatering fine coal  

SciTech Connect

Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up the millions of tons of coal fines in refuse piles and ponds. It is anticipated that the new centrifuge can become an important ancillary to the advanced deep cleaning processes for coal. Because of these convictions, CTC has been engaged in a pioneering research effort into the new art of drying fine clean coal in high gravity, high production, batch type centrifuges, since 1981. This work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. It promises to provide needed fine coal drying capability at somewhat lower capital costs and at substantially lower operating costs than competitive systems. It also promises to do so with no detrimental effects on either the coal quality or the evironment. The primary objective of this project is to prove the concept in a commercial coal processing plant environment. The proof of concept tests will also include testing with a variety of coals from different regions. A further objective will be to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology.

Smith, L.B.; Durney, T.E. Jr.

1990-07-24

251

Feasibility study of the anaerobic digestion of dewatered pig slurry by means of polyacrylamide  

Microsoft Academic Search

Liquid livestock waste can be managed by separating liquid and solid fractions then treating each separately by applying best available technology, such as anaerobic digestion for the solid fraction. There is an increasing use of polyacrylamide (PAM) as a flocculant agent to improve solid–liquid separation. In the present work, the anaerobic toxicity of PAM residues and the optimal range of

E. Campos; M. Almirall; J. Mtnez-Almela; J. Palatsi; X. Flotats

2008-01-01

252

Ultrafine coal single stage dewatering and briquetting process. Technical report, December 1, 1994--February 28, 1995.  

National Technical Information Service (NTIS)

It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin, are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ult...

J. W. Wilson

1996-01-01

253

Modeling consolidation and dewatering near the toe of the northern Barbados accretionary complex  

USGS Publications Warehouse

At the toe of the northern Barbados accretionary complex, temperature and pore water chemistry data indicate that fluid flow is channeled along the de??collement and other shallow thrust faults. We examine mechanisms that may prevent consolidation and maintain high permeability over large sections of the de??collement. High-resolution bulk density data from five boreholes show that the de??collement is well consolidated at some sites while other sites remain underconsolidated. Underconsolidated de??collement behavior is associated with kilometer-scale negative-polarity seismic reflections from the de??collement plane that have been interpreted to be fluid conduits. We use a coupled fluid flow/consolidation model to simulate the loading response of a 10-km-long by 680-m-thick slice of sediment as it enters the accretionary complex. The simulations capture 185 ka (5 km) of subduction, with a load function representing the estimated effective stress of the overriding accretionary prism (3.8?? taper angle). Simulation results of bulk density in the de??collement 3.2 km arcward of the deformation front are compared with observations. The results show that persistent high pore pressures at the arcward edge of the simulation domain can explain underconsolidated behavior. The scenario is consistent with previous modeling results showing that high pore pressures can propagate intermittently along the de??collement from deeper in the complex. Simulated seaward fluxes in the de??collement (1-14 cm yr-1) lie between previous estimates from modeling studies of steady state (1 m yr-1) flow. Maximum simulated instantaneous fluid sources (2.5??10-13 s-1) are comparable to previous estimates. The simulations show minor swelling of incoming sediments (fluid sources ??? -3 ?? 1015 s-1) up to 3 km before subduction that may help to explain small-scale shearing and normal faulting proximal to the protode??collement. Copyright 2001 by the American Geophysical Union.

Stauffer, P.; Bekins, B. A.

2001-01-01

254

Enhanced dewatering of waste sludge with microbial flocculant TJ-F1 as a novel conditioner.  

PubMed

Microbial flocculant (MBF) TJ-F1 with high flocculating activity was investigated to be used as a novel conditioner for the enhanced dewaterability of the waste sludge from wastewater treatment plant (WWTP). The experimental results showed that TJ-F1 was better than poly(acrylamide [2-(Methacryloyloxy)ethyl]trimethylammonium chloride) (P(AM-DMC)), the most commonly used conditioner in China, in improving the dewaterability of the waste sludge in terms of both the specific resistance in filtration (SRF) and the time to filter (TTF). The key parameters influencing the dewaterability of the waste sludge conditioned by TJ-F1, including the system pH, CaCl(2) concentration and TJ-F1 concentration, were systematically investigated. The favorite pH for the conditioning process was around the neutral. CaCl(2) was found to be a good conditioning aid to TJ-F1. A right dosage of TJ-F1 was decisive for the conditioning process. The optimized conditioning process is that about 0.17% (w/w) TJ-F1 and 1.3% (w/w) CaCl(2) are added into the sludge, and then the system pH was adjusted to 7.5. The compound use of TJ-F1 and P(AM-DMC) was also testified to be feasible in improving the dewaterability of the waste sludge. PMID:20236680

Zhang, Zhiqiang; Xia, Siqing; Zhang, Jiao

2010-03-01

255

Surface settlements at a soft soil site due to bedrock dewatering  

Microsoft Academic Search

Construction of a 16-m deep, 55-m wide, almost square, underground structure through 8-m of soft soils and 8-m of sandstone and siltstone led to the development of widespread settlements. The affected area extended to distances of over 200 m from the perimeter of the structure. The floor slab of the underground structure was not designed for water pressure. Thus, operation of

Debasis Roy; Keith E. Robinson

2009-01-01

256

Contaminated water treatment in cold regions: an example of coagulation and dewatering modelling in Antarctica  

Microsoft Academic Search

Water collection and treatment is often required for effective cold regions contaminated site clean-up, where large volumes of meltwater runoff might otherwise become contaminated during remediation activities and disperse pollutants into the surrounding environment. Waste reduction is particularly important for remediation activities in remote cold regions, as the handling, transport and eventual disposal of material is very costly and logistically

Kathy A. Northcott; Ian Snape; Peter J. Scales; Geoff W. Stevens

2005-01-01

257

Dewatering Treatment Scale-up Testing Results of Hanford Tank Wastes  

Microsoft Academic Search

This report documents CH2M HILL Hanford Group Inc. (CH2M HILL) 2007 dryer testing results in Richland, WA at the AMEC Nuclear Ltd., GeoMelt Division (AMEC) Horn Rapids Test Site. It provides a discussion of scope and results to qualify the dryer system as a viable unit-operation in the continuing evaluation of the bulk vitrification process. A 10,000 liter (L) dryer\\/mixer

A. R. Tedeschi; T. H. May; W. E. Bryan

2008-01-01

258

Dewatering Treatment Scale-up Testing Results of Hanford Tank Wastes  

SciTech Connect

This report documents CH2M HILL Hanford Group Inc. (CH2M HILL) 2007 dryer testing results in Richland, WA at the AMEC Nuclear Ltd., GeoMelt Division (AMEC) Horn Rapids Test Site. It provides a discussion of scope and results to qualify the dryer system as a viable unit-operation in the continuing evaluation of the bulk vitrification process. A 10,000 liter (L) dryer/mixer was tested for supplemental treatment of Hanford tank low activity wastes, drying and mixing a simulated non-radioactive salt solution with glass forming minerals. Testing validated the full scale equipment for producing dried product similar to smaller scale tests, and qualified the dryer system for a subsequent integrated dryer/vitrification test using the same simulant and glass formers. The dryer system is planned for installation at the Hanford tank farms to dry/mix radioactive waste for final treatment evaluation of the supplemental bulk vitrification process. (authors)

Tedeschi, A.R.; May, T.H.; Bryan, W.E. [CH2M HILL Hanford Group, Inc. Richland, WA (United States)

2008-07-01

259

Theories of cake filtration and consolidation and implications to sludge dewatering  

Microsoft Academic Search

This work presents a mini-review of the various theories in previous literature while considering the transport processes in filter cakes during filtration and consolidation. The development of the conventional two-resistance theory (referred to herein as conventional theory) is initially discussed based on different types of power-law constitutive equations. Multi-phase theory is then described, along with the criticisms raised by Willis

D. J. Lee; C. H. Wang

2000-01-01

260

Flocculation and dewatering of kaolin suspensions in the presence of polyacrylamide and surfactants  

Microsoft Academic Search

Flocculation, as a result of the interaction between non-ionic polyacrylamide polymer (PAM-N) and kaolin surface in aqueous suspension, has been discussed both in the absence and in the presence of surfactants namely, cationic cetyl trimethyl ammonium bromide (CTAB), anionic sodium dodecyl sulphate (SDS) and non-ionic TX 100. The results of separation properties have been discussed in the light of kaolin

L Besra; D. K Sengupta; S. K Roy; P Ay

2002-01-01

261

46 CFR 28.815 - Bilge pumps, bilge piping, and dewatering systems.  

Code of Federal Regulations, 2012 CFR

...minute, connected to a bilge manifold and piping capable of draining any watertight compartment, other than tanks and small buoyancy compartments, under all service conditions. Large spaces, such as engine rooms and cargo holds must be fitted with...

2012-10-01

262

Grafting polyelectrolytes onto polyacrylamide for flocculation 2. Model suspension flocculation and sludge dewatering  

Microsoft Academic Search

Low-molecular-weight high-charge-density cationic poly(diallyldimethylammonium chloride) (polyDADMAC) was grafted onto high-molecular-weight\\u000a nonionic polyacrylamide (PAM) via a free radical mechanism using a gamma radiation technique. The graft copolymers having\\u000a various charge densities were evaluated as flocculants for titanium dioxide (TiO2) model suspensions, and as conditioners for a pulp and paper mill sludge. Their flocculation performance was optimized with\\u000a respect to polymer composition,

M. Ma; S. Zhu

1999-01-01

263

Experimental analysis of centrifugal dewatering process of polyelectrolyte flocculated waste activated sludge  

Microsoft Academic Search

The study experimentally investigated the centrifugal separation of moisture from activated sludge subject to cationic polyelectrolyte flocculation. An arm-suspended centrifuge was employed which allowed in-situ detection on all positions of interfaces of centrifuged sludge as functions of time. Experimental results revealed that, sludge flocculation would yield a significant sedimentation effect at the first phase of centrifugation. Therefore, not as suggested

C. P Chu; D. J Lee

2001-01-01

264

Enhanced dewatering of waste sludge with microbial flocculant TJ-F1 as a novel conditioner  

Microsoft Academic Search

Microbial flocculant (MBF) TJ-F1 with high flocculating activity was investigated to be used as a novel conditioner for the enhanced dewaterability of the waste sludge from wastewater treatment plant (WWTP). The experimental results showed that TJ-F1 was better than poly(acrylamide [2-(Methacryloyloxy)ethyl]trimethylammonium chloride) (P(AM-DMC)), the most commonly used conditioner in China, in improving the dewaterability of the waste sludge in terms

Zhiqiang Zhang; Siqing Xia; Jiao Zhang

2010-01-01

265

Interaction of polyelectrolyte with digested sewage sludge and lignite in sludge dewatering  

Microsoft Academic Search

Physical conditioners, often known as skeleton builders, are commonly used for enhancing the rate and the extent of water removal of polyelectrolyte-flocculated sewage sludge. In this study, the interactions of two different cationic polyelectrolytes with lignite (a low rank coal) in conditioning of digested sewage sludge are investigated. Vacuum filtration tests, zeta potential measurements and floc population measurements are performed

K. B. Thapa; Y. Qi; A. F. A. Hoadley

2009-01-01

266

Removal of inorganic constituents of biomass feedstocks by mechanical dewatering and leaching  

Microsoft Academic Search

Inorganic constituents of ash in biomass fuels are responsible for equipment failure and operating difficulties in thermochemical energy conversion facilities. Alkali metals, in the presence of chlorine and sulfur, are the leading contributors to this problem. Banagrass, a herbaceous species being considered for use as a dedicated energy crop, contains high levels of potassium and chlorine. Some inorganic elements are

Scott Q. Turn; Charles M. Kinoshita; Darren M. Ishimura

1997-01-01

267

Particulates in hydrometallurgy: Part III. Dewatering behavior of flocculated laterite acid leach residues  

Microsoft Academic Search

Three polyacrylamide-based polymers of different chemical properties (polymer A, 34 pct anionic, 11?106 mol wt; polymer B, 7 pct anionic, 7.5?106 mol wt; polymer C, nonionic, 13.5?106 mol wt) were used to evaluate the flocculation behavior of laterite acid leach residues. The solid-liquid separation characteristics\\u000a of the leach residues were investigated with the aid of settling rate, supernatant turbidity, and

A. Briceno; K. Osseo-Asare

1995-01-01

268

Modeling the dewatering and depressurization of the Lihir open-pit gold mine, Papua New Guinea  

Microsoft Academic Search

The open pit at the Lihir Gold Mine, Papua New Guinea, is planned ultimately to reach more than 200m below sea level. Cooling and depressurization of the geothermal resource associated with the gold mineralisation is an essential part of the mining operation. This paper deals with the development of a numerical model of the resource capable of representing reservoir processes

Stephen P White; Ashley L Creighton; Paul F Bixley; Warwick M Kissling

2004-01-01

269

MODELLING THE DEWATERING AND DEPRESSURISATION OF THE LIHIR OPEN PIT GOLD MINE  

Microsoft Academic Search

The open pit at the Lihir Gold Mine, Papua New Guinea is planned to ultimately reach more than 200 metres below sea level. Cooling and depressurisation of the geothermal resource associated with the gold mineralisation is an essential part of the mining operation. Eight deep, deviated geothermal wells were completed during 1999 to investigate geothermal conditions beneath the mine pit.

Stephen P. White; Ashley L. Creighton; Paul F. Bixley; Warwick M. Kissling

2003-01-01

270

46 CFR 28.255 - Bilge pumps, bilge piping, and dewatering systems.  

Code of Federal Regulations, 2011 CFR

...Strainers must have an open area of not less than three times the open area of the suction line. (h) Each vessel must comply with the oil pollution prevention requirements of 33 CFR parts 151 and...

2011-10-01

271

46 CFR 28.255 - Bilge pumps, bilge piping, and dewatering systems.  

Code of Federal Regulations, 2012 CFR

...Strainers must have an open area of not less than three times the open area of the suction line. (h) Each vessel must comply with the oil pollution prevention requirements of 33 CFR parts 151 and...

2012-10-01

272

Electro-Kinetic Technology as a Low-Cost Method for Dewatering Food By-Product  

Microsoft Academic Search

Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food by-products that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This

Sing K. Ng; Andrew Plunkett; Valentina Stojceska; Paul Ainsworth; John Lamont-Black; Jean Hall; Chris White; Stephanie Glendenning; David Russell

2011-01-01

273

Water based demulsifier formulation and process for its use in dewatering and desalting crude hydrocarbon oils  

SciTech Connect

A process for separating emulsified water from water-in-crude oil emulsion produced from underground reservoirs is described which comprises: (a) dispersing from 1 volume ppm to 50 volume ppm of a water soluble demulsifier into the crude oil containing water emulsified therein the parts being based on the volume of the oil; (b) permitting the water to separate from the crude oil; and (c) removing the water from the crude oil.

Merchant, P. Jr.; Lacy, S.M.

1988-04-12

274

An Alternative Septage Treatment Method: Lime Stabilization/Sand-Bed Dewatering.  

National Technical Information Service (NTIS)

Few desirable methods exist for disposing of the sludge that is periodically pumped from septic tanks. This report describes the results obtained from a pilot study of one alternative septage treatment method-lime stabilization followed by covered sand-be...

E. T. Oppelt J. F. Kreissl W. A. Feige

1975-01-01

275

REACTIVATION AND REGROWTH OF INDICATOR ORGANISMS ASSOCIATED WITH ANAEROBICALLY DIGESTED AND DEWATERED BIOSOLIDS: EPA’S PERSPECTIVE  

EPA Science Inventory

The Water Environment Research Foundation (WERF) recently published a report titled Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bacte...

276

HETEROCYCLIC SYNTHESIS WITH NITRILES: SYNTHESIS OF SOME NEW THIOPHENE AND THIENO[2,3-d]PYRIMIDINF2 DEWATIVES IV  

Microsoft Academic Search

?-(thiocyanatomethyl) benzylidenemalononitde (1) undergoes hydrolysis followed by cyclization to atford 2-amino-4-phenylthiophene-3-carbonitrile (2) on reflux in acetic\\/dil. hydrochloric acid mixture. Compound 2 reacts with dil. sulfuric acid, phenacyl bromide, potassium hydroxide, and phenyl isothiocyanate to afford the thiophene derivatives 3.8, 15 and 17 respectively. The reaction of 2 with acetic anhydride, benzoylacetonitrile, phenacyl thiocyanate, and benzoyl isothiocyanate led to the formation

Fathy M. Abdelrazek

1996-01-01

277

Proof of concept and performance optimization of high gravity batch-type centrifugal dryer for dewatering fine coal  

SciTech Connect

The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer's systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)

Smith, L.B.; Durney, T.

1991-01-01

278

Pilot scale single stage fine coal dewatering and briquetting process. Technical report, September 1--November 30, 1995.  

National Technical Information Service (NTIS)

The primary goal of the current coal preparation research is to reduce the ash and sulfur content from coal, using fine grinding and various coal cleaning processes to separate finely disseminated mineral matter and pyrite from coal. Small coal particles ...

J. W. Wilson Y. Ding R. Q. Honaker

1995-01-01

279

Pilot scale single stage fine coal dewatering and briquetting process. Final technical report, September 1, 1995--August 31, 1996.  

National Technical Information Service (NTIS)

The primary goal of the ongoing ICCI coal preparation research project is to reduce ash and sulfur content in coal by using fine grinding and other coal cleaning processes. The ultrafine coal particles that result from the grinding and cleaning operations...

J. W. Wilson R. Q. Honaker Y. Ding

1997-01-01

280

Evaluation of hyperbaric filtration for fine coal dewatering. Second Quarterly technical progress report, December 1, 1992--February 28, 1993  

SciTech Connect

The normal practice in the coal preparation plant is to remove the water from the fine coal slurry by vacuum filtration and drying. Conventional vacuum filtration typically produces filter cake moisture containing in the range of 25 to 30 weight percent from minus 28 mesh coal slurries. Although the desired product quality can be obtained by using thermal dryers, there are problems associated with these equipment such as high capital costs and the greatest potential source of air pollution in a coal cleaning plant. In the present research project, an alternative to thermal drying, hyperbaric filtration which has shown potential in lowering moisture content in fine coal to about 20 percent level, is being investigated in detail. This project will essentially focus on developing fundamental information on particle-liquid interaction during hyperbaric filtration and applying the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.

Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL, Inc., Pittsburgh, PA (United States)

1993-06-01

281

Tannery Waste Treatment: Leaching, Filtration and Cake Dewatering Using a Membrane Filter Press (a Pilot Plant Study)  

Microsoft Academic Search

In Alcanena (Portugal) the waste water treatment plant (WWTP) receives tannery waste, after a pretreatment for sulphides and the tanning exhaust baths have been sent to a recovery unit and the municipal waste water from Alcanena residential area. Physical, chemical, and biological treatment processes are involved, and the end products are sludge of ?71% moisture containing mainly organic matter, sulfides,

P. F. M. Correia; J. M. R. de Carvalho

2005-01-01

282

Laboratory tests to assess water-level fluctuations at Vernita Bar, Washington, USA. [Effects on chinook salmon redd  

SciTech Connect

Vernita Bar chinook salmon redd dewatering was simulated in gravel-filled aquaria. Dewatering before hatching did not affect survival; after hatching a few hours of dewatering was fatal. Weather conditions at Vernita Bar was not a factor in assessing dewatering effects. Above-ground watering of dewatered redds may protect alevins and eleutheroembryos.

Neitzel, D.A.; Becker, C.D.; Abernethy, C.S.

1985-02-01

283

Tracing and quantifying lake water and groundwater fluxes in the area under mining dewatering pressure using coupled O and H stable isotope approach.  

PubMed

Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (?(2)H from-140 to+13 ‰ and ?(18)O from-19.3 to+7.6 ‰), the lake waters were variously affected by evaporation (?(2)H from-44 to-21 ‰ and ?(18)O from-5.2 to-1.7 ‰) and the groundwater showed varying contribution from mixing with surface water (?(2)H from-75 to-39 ‰ and ?(18)O from-10.4 to-4.8 ‰). The lake water budget was estimated using a Craig-Gordon model and isotopic mass balance constraint, which enabled us to identify various water sources and to quantify inflow and outflow for each lake. Moreover, we documented that a variable recharge of lake water into the Tertiary aquifer was dependent on mining drainage intensity. A comparison of coupled ?(2)H-?(18)O data with hydrogeological results indicated better precision of the ?(2)H-based calculations. PMID:22775141

Lewicka-Szczebak, Dominika; J?drysek, Mariusz-Orion

2012-07-10

284

Numerical investigation of dewatering and fluid pressure in the western Nankai subduction zone: Implications for fluid flow and mechanical behavior of the subduction thrust  

NASA Astrophysics Data System (ADS)

Excess pore water pressure is one of crucial factors that controls the nature and physical property of the plate boundary and, thus, the updip limit of the seismogenic zone. Variation of sediment composition and lithostratigraphy are key players for the spatial distribution and magnitude of fluid pressures. To investigate their impact we chose the underthrust sequence of the western Nankai subduction zone offshore Japan for our study. Sand layers characterize the incoming sediment sequence at the western Nankai margin with a total thickness of up to >200 m within a matrix of hemipelagic mud. We use a coupled loading and diffusion model that allows continuous sediment deformation. To investigate the impact of sand layers on fluid flow and fluid pressures hydrogeological properties are updated in the models based on new laboratory reference data of clays and sands from the Nankai margin area. The simulations demonstrate that ~79-89% of the incoming pore water in the underthrust sediment may be expelled by lateral fluid flow along the sands, which are at least partially cycled back to the ocean. Different deformation behavior of sands and clays enhances the effective sand permeability to be 5-24 times higher than the matrix sediment. The average pore pressure ratio along the base of the accretionary prism is lower than along the central Nankai margin where sand layers are absent. This result emphasizes that sediment lithostratigraphy is a key player for the along-strike variation in mechanical strength of the subduction thrust. The numerical study also suggests that lateral fluid flow mediates the distribution of effective stress in the underthrusting sediments, and may cause downstepping of the décollement ~20-30 km landward of the trench (as observed in seismic reflection profiles) and initiates underplating in the Nankai subduction zone.

Huepers, Andre; Saffer, Demian M.; Kopf, Achim J.

2013-04-01

285

Tracing and quantifying lake water and groundwater fluxes in the area under mining dewatering pressure using coupled O and H stable isotope approach  

Microsoft Academic Search

Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (?H

Dominika Lewicka-Szczebak; Mariusz-Orion J?drysek

2012-01-01

286

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 December--28 February 1993  

SciTech Connect

This project is concerned with a basic scientific question concerning the properties of coal- to what extent is the ability of coal to hold moisture a manifestation of the well-known ability of coal to swell, when exposed to good solvents? This quarter`s efforts involved continuing to use the flow microcalorimeter as a tool for characterizing the heat effects involved in interaction of swelling solvents and coals. These data are of relevance to the overall project goal of establishing that moisture retention is a solvent swelling process. During this quarter, we used the flow microcalorimeter to explore heat effects as a function of concentration of solute. Earlier results had strongly suggested that the heat effect is large in going from zero to small concentrations, but that once the concentration was above a low levels, there would be relatively small effects of concentration.

Suuberg, E.M.

1993-09-01

287

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 March31 May 1993  

Microsoft Academic Search

It has been noted that there is no single, distinct measure of the bulk modulus of coals measurable in mercury porosimetry experiments. As with other modulus measurements on coal, there is a hysteresis associated with these measurements of bulk modulus. The hysteresis is presumably associated with the time-dependent reorganization of its macromolecular network structure, in response to the applied stresses.

E. M. Suuberg; Y. Yun; W. D. Lilly; K. Leung; T. Gates; Y. Otake; S. C. Deevi

1993-01-01

288

Proof of concept and performance optimization of high gravity batch-type centrifugal dryer for dewatering fine coal. Final report, September 20, 1989--September 21, 1991  

SciTech Connect

The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer`s systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)

Smith, L.B.; Durney, T.

1991-12-31

289

Optimization of the polyelectrolyte dosage for dewatering sewage sludge suspensions by means of a new centrifugation analyser with an optoelectronic sensor  

Microsoft Academic Search

The flocculation of sewage sludge with poly(diallyldimethylammonium chloride) (PDADMAC) as well as cationic, poly[acrylamide-co-(N,N,N-trimethylammoniumethylacrylate chloride)] (PTAC), and anionic acrylamide copolymers, poly(acrylamide-co-acrylate) (PAAM\\/AA), was investigated by using a new method to evaluate the velocity of centrifugal separation and the packing\\u000a behaviour of the sediments. By means of a centrifugation analyser with an optoelectronic measuring system the position of\\u000a the centrate\\/sediment interface

A. von Homeyer; D.-O. Krentz; W.-M. Kulicke; D. Lerche

1999-01-01

290

Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: Isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering  

Microsoft Academic Search

Wastewater treatment plants often face the problems of sludge settling mainly due to sludge bulking. Generally, synthetic organic polymer and\\/or inorganic coagulants (ferric chloride, alum and quick lime) are used for sludge settling. These chemicals are very expensive and further pollute the environment. Whereas, the bioflocculants are environment friendly and may be used to flocculate the sludge. Extracellular polymeric substances

S. Bala Subramanian; S. Yan; R. D. Tyagi; R. Y. Surampalli

2010-01-01

291

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 September--30 November 1992  

SciTech Connect

The picture that emerges is that there are quite large heat effects associated with low uptakes of solvents by the coal. The fact that the heat of wetting decreases dramatically with uptake has been illustrated many times. The final equilibrium uptake of solvent in a swollen coal probably takes place at near zero partial molar enthalpy of mixing, as we have argued earlier. It would, however, be interesting to establish what sorts of interactions give rise to the high initial heats of mixing. The trend of increasing heat of mixing with increasing temperature has also been earlier noted. It too is not yet understood.

Suuberg, E.M.

1992-12-31

292

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering  

DOEpatents

It is an object of the claimed invention to combine chemical treatment with microfiltration process to treat groundwater, leachate from contaminated soil washing, surface and run-off waters contaminated with toxic metals, radionuclides and trace amounts of organics from variety of sources. The process can also be used to treat effluents from industrial processes such as discharges associated with smelting, mining and refining operations. Influent contaminants amenable to treatment are from a few mg/L to hundreds of mg/L. By selecting appropriate precipitation, ion exchange and adsorption agents and conditions, efficiencies greater than 99.9 percent can be achieved for removal of contaminants. The filtered water for discharge can be targeted with either an order of magnitude greater or lower than contaminant levels for drinking water.

Vijayan, S.; Wong, Chi Fun; Buckley, L.P.

1992-12-31

293

40 CFR 435.44 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

Code of Federal Regulations, 2013 CFR

...exceed 48 mg/l. Drilling Fluids and Drill Cuttings and Dewatering Effluent: 1 All facilities except Cook Inlet No discharge. Cook Inlet: Water-based drilling fluids, drill cuttings, and dewatering effluent Free Oil No...

2013-07-01

294

Effects of ultrafiltration membrane concentration and drying temperature on nutritional value of biosolids from a milk processing plant  

Microsoft Academic Search

Biosolids (sludge) from food processing plants traditionally are put into landfills or applied to land. They could be reused as animal food but have to be dewatered. Conventional dewatering methods are expensive and inefficient. Recent advancements in membrane technology could make ultrafiltration membranes a practical biosolids dewatering method used prior to conventional drying. Ultrafiltration could alter the nutritional profile of

L. D le Roux; R. L Belyea

1999-01-01

295

Proof of concept and performance optimization of high gravity batch type centrifuge for dewatering fine coal. Quarterly technical progress report No. 3, March 20, 1990--June 20, 1990, Revision  

SciTech Connect

Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up the millions of tons of coal fines in refuse piles and ponds. It is anticipated that the new centrifuge can become an important ancillary to the advanced deep cleaning processes for coal. Because of these convictions, CTC has been engaged in a pioneering research effort into the new art of drying fine clean coal in high gravity, high production, batch type centrifuges, since 1981. This work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. It promises to provide needed fine coal drying capability at somewhat lower capital costs and at substantially lower operating costs than competitive systems. It also promises to do so with no detrimental effects on either the coal quality or the evironment. The primary objective of this project is to prove the concept in a commercial coal processing plant environment. The proof of concept tests will also include testing with a variety of coals from different regions. A further objective will be to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology.

Smith, L.B.; Durney, T.E. Jr.

1990-07-24

296

40 CFR 717.7 - Persons not subject to this part.  

Code of Federal Regulations, 2013 CFR

...odorant, antioxidant, filler, solvent, carrier, surfactant, plasticizer, corrosion inhibitor, antifoamer or defoamer, dispersant, precipitation-inhibitor, binder, emulsifier, deemulsifier, dewatering agent, agglomerating...

2013-07-01

297

40 CFR 710.4 - Scope of the inventory.  

Code of Federal Regulations, 2013 CFR

...odorant, antioxidant, filler, solvent, carrier, surfactant, plasticizer, corrosion inhibitor, antifoamer or de-foamer, dispersant, precipitation inhibitor, binder, emulsifier, de-emulsifier, dewatering agent,...

2013-07-01

298

A Novel Geotechnical/Geostatistical Approach for Exploration and Production of Natural Gas from Multiple Geologic Strata: Quarterly report, January 1-March 31, 1997  

SciTech Connect

This report discusses dewatering and production extension test periods, and the demonstration of newly developed technologies for multi-strata gas and water production to enhance commercial applications.

NONE

1997-12-31

299

Suspended sediment, dissolved organic carbon, and dissolved nitrogen export during the dam removal process  

Microsoft Academic Search

(1) Total suspended solids (TSS), dissolved organic carbon (DOC), and total dissolved nitrogen (TDN) loads were calculated for all stages of the dam removal process (dewatering, breaching, and removal) at various points upstream, within, and downstream of Lowell Mill Impoundment on the Little River, North Carolina. The impoundment dewatering exported loads of TSS, DOC, and TDN which were all 1-2

J. Adam Riggsbee; Jason P. Julian; Martin W. Doyle; Robert G. Wetzel

2007-01-01

300

Influences of influent carbon source on extracellular polymeric substances (EPS) and physicochemical properties of activated sludge  

Microsoft Academic Search

It is necessary to understand the bioflocculation, settling and dewatering characteristics in the activated sludge process in order to establish more efficient operational strategies. The influences of carbon source on the extracellular polymeric substances (EPS) and flocculation, settling and dewatering properties of the activated sludge were investigated. Laboratory-scale completely mixed activated sludge processes were used to grow the activated sludge

FenXia Ye; Ge Peng; Ying Li

2011-01-01

301

Volume reduction and encapsulation process for water containing low-level radioactive waste  

SciTech Connect

Solutions or slurries of waste material in water are dewatered and encapsulated within a polymer for disposal, comprising the operations of removing water therefrom with azeotropic mixture evaporation and encasing the dewatered waste residue in an organic polymer. The method and system disclosed are especially useful for the safe disposal of radioactive waste.

Fox, D.W.; Miller, G.P.; Weech, M.E.

1984-02-28

302

Effect of total solids on fecal coliform regrowth in anaerobically digested biosolids  

Microsoft Academic Search

Fecal coliform (FC) concentrations in anaerobically digested biosolids can increase during centrifugal dewatering and afterwards in storage of dewatered cake. The immediate increase after centrifugation (reactivation) has been demonstrated to be the revitalization of fecal coliforms that had become non-culturable. The increase during storage (regrowth) has been regarded as a subsequence of reactivated bacteria growing in a favorable environment. In

Yinan Qi; Steven K. Dentel; Diane S. Herson

2008-01-01

303

Method and system for recovering coal fines from pipe line coal slurry  

Microsoft Academic Search

A method and system for dewatering coal fines from the concentrate of a pipeline slurry centrifuge, to recover the coal and purify the water, includes blending the concentrate from the centrifuge with slurry from the pipeline in the proportion of about 4:1. The blend is chemically conditioned with an agglomerating polymer, and then dewatered on a belt press. The cake

P. R. Erickson; K. A. Pietila

1985-01-01

304

Research of the model on recycling utilization of oil sludge  

Microsoft Academic Search

The research object of our study is oil sludge produced in petrochemical wastewater treatment. A technical option is proposed in conditioning and dewatering of oil sludge, recycling of gas condensate and malysite so as to minimize the oil containing sludge, fully utilize resources and to protect environment. Results show that the structure of oil sludge is improved and the dewatering

Bo Zhou; Nairui Liu

2012-01-01

305

Confined-unconfined changes above longwall coal mining due to increases in fracture porosity  

Microsoft Academic Search

Subsidence and strata movement above longwall (total extraction) coal mines produce complex hydrologic responses that can occur independently of drainage to the mine. One response is dewatering from confined to unconfined conditions in bedrock aquifers as a result of loss of water into new void space created by fracture and bedding separations. This dewatering process has been little studied but

C. J BOOTH

2007-01-01

306

Method and apparatus for purifying and compacting solid wastes  

Microsoft Academic Search

An apparatus for purifying and dewatering an infectious and hazardous solid waste comprising in combination: (a) an enclosed reactor comprising an enclosure having a top, side walls, a bottom outside wall, an inlet door and an inlet pipe on or near the top thereof for receiving the solid waste, the apparatus comprising a means for purifying, dewatering and separating the

L. K. Wang; M. H. S. Wang

1993-01-01

307

Determination of Carbon\\/Nitrogen Ratio and Heavy Metals in Bulking Agents Used for Sewage Composting  

Microsoft Academic Search

Improving the soil quality with organic matter content and presence of elements such as N, P and K are some of sewage sludge benefits. Adjusting carbonaceous materials such as plant wastes to dewatered sludge compost increases its moisture and improves C\\/N ratio. So dewatered sludge has low C\\/N ratio and should be mixed with bulking agents. This study was performed

A Parvaresh; H Alidadi

2004-01-01

308

Appalachian Clean Coal Technology Consortium: Technical progress report, October 1--December 31, 1995  

SciTech Connect

In the dewatering project, two different approaches are taken. One approach involves displacing the water on the surface of coal by a hydrophobic substance that can be readily recovered and recycled. This novel concept, referred to as the Hydrophobic Dewatering (HD) process, is based on improved understanding of the surface chemistry of dewatering. The other approach is to use disposable dewatering substances in mechanical dewatering. The objectives of the proposed work are (1) to test the HD process on a variety of coals from the Appalachian coal fields, and (2) to identify suitable dewatering reagents that would enable mechanical dewatering to reduce the moisture to the levels satisfactory to electrical utilities and other coal users. The objective of the spiral separation project is to use computer modeling to develop better, more efficient spiral designs for coal cleaning. The fully-developed model will predict spiral performance based on variations in spiral profile, flow rate, and pitch. Specific goals are to: (1) design spirals capable of making separations at a specific gravity of 1.5, and (2) broaden the size range at which spirals make effective separations.

NONE

1996-04-23

309

Cost estimate for a coal slurry pipeline in western Sumatra  

SciTech Connect

Contents: Introduction to pipeline slurry transport; Calculation of pressure drop due to friction; Calculation of the total pressure drop; Determination of the type of pumps; Wall thickness and the cost of the pipe; Storage capacity; Dewatering; Grinding; Cost evaluation.

Kappelle, H.J.

1982-08-01

310

USE OF SEWAGE SLUDGE FOR FOREST-TREE SEEDLING PRODUCTION  

EPA Science Inventory

Research was undertaken to determine the beneficial and harmful effects of using dewatered, digested sewage sludge in: (1) containerized production of forest tree seedlings, (2) tree seedling production in a conventional outdoor nursery, (3) establishment and growth of transplant...

311

Particle Technology Research at the University of Technology, Loughborough, England.  

National Technical Information Service (NTIS)

The report summarizes research activities of the particle technology group at the University of Technology, Loughborough, England. Included are discussions on stresses in granular material, pore size distribution, dewatering, solid particles in fluidized ...

R. T. Boverie

1969-01-01

312

Third technical contractors' conference on peat  

SciTech Connect

The conference dealt with the estimation of US peat reserves, methods for the gasification of peat, including biogasification, techniques for dewatering peat, and the harvesting of peat. Separate abstracts were prepared for the individual papers. (CKK)

Not Available

1981-01-01

313

Tube Fabrication from Collagen/Glycosaminoglycan Dispersions.  

National Technical Information Service (NTIS)

Two processes for fabricating seamless tubes from dispersions of collagen/glycosaminoglycan (GAG) complexes were designed. The first process makes use of cross flow filtration in order to dewater the dispersion and cause its deposition on the inside wall ...

I. V. Yannas M. J. Forbes J. A. Stein E. W. Salzman

1978-01-01

314

MUNICIPAL WASTEWATER SLUDGE COMBUSTION TECHNOLOGY  

EPA Science Inventory

The publication describes and evaluates the various municipal sludge combustion systems. It also emphasizes the necessity for considering and evaluating the costs involved in the total sludge management train, including dewatering, combustion, air pollution control, and ash dispo...

315

40 CFR 420.02 - General definitions.  

Code of Federal Regulations, 2012 CFR

...boiler blowdown, and air pollution control wastewaters from heat recovery equipment); treated or untreated wastewaters from groundwater remediation systems; dewatering water for building foundations; and other wastewater streams not associated with a...

2012-07-01

316

Sewage Sludge Incinerator Fuel Reduction, Hartford, Connecticut.  

National Technical Information Service (NTIS)

A field demonstration project was conducted at Hartford, Connecticut, which showed that the supplemental fuel usage for sewage sludge incineration could be reduced 83%. This was accomplished by using a belt press filter for dewatering which reduced fuel u...

A. J. Verdouw E. W. Waltz P. F. Gilbert

1984-01-01

317

Feasibility of Reducing Production and Distribution Costs of Minnesota Peat to a Competitive Level.  

National Technical Information Service (NTIS)

The principal objectives were to make comprehensive studies of the basic factors relating to production of peat such as ditch spacings, water levels, bog preparation, harvesting and drying techniques, artificial dewatering and etc. Other objectives were t...

1968-01-01

318

EVALUATION OF BIOAEROSOL COMPONENTS, GENERATION FACTORS, AND AIRBORNE TRANSPORT ASSOCIATED WITH LIME TREATMENT OF CONTAMINATED SEDIMENT  

EPA Science Inventory

Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well kno...

319

163. VIEW OF TWO JOHNS MINE PORTAL FROM EAST. NOTE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

163. VIEW OF TWO JOHNS MINE PORTAL FROM EAST. NOTE WATER LINE ON BRIDGE; DEWATERING MINE SUPPLIED A PORTION OF THE MILL'S WATER SUPPLY. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

320

An Environmental Evaluation of Polyethylene Oxide When Used as a Flocculant for Clay Wastes.  

National Technical Information Service (NTIS)

The Bureau of Mines, U.S. Department of the Interior, has developed a novel method of flocculation dewatering of phosphatic clay wastes using polyethylene oxide as the flocculant. Research was conducted to determine whether ethylene oxide gas was present ...

J. R. Zatko

1980-01-01

321

IMPROVING DESIGN AND OPERATION OF HEAT TREATMENT/LOW PRESSURE OXIDATION SYSTEMS  

EPA Science Inventory

The purpose of the investigation is to document possible improvements to design, operation, and maintenance of heat treatment and low pressure oxidation systems for conditioning sludge prior to dewatering in municipal wastewater treatment plants. The information in the report is ...

322

40 CFR 240.201-2 - Recommended procedures: Design.  

Code of Federal Regulations, 2011 CFR

...Examples of wastes which should be considered for exclusion from the facility include: Hazardous wastes, very large carcasses, automobile bodies, dewatered sludges from water treatment plants, and industrial process...

2011-07-01

323

Implementation document for groundwater intercept and treatment system, basin a neck IRA. Volume 3: Engineering drawings  

SciTech Connect

The Basin A Neck interim response action will consist of: 1. Seven dewatering wells; 2. Soil bentonite slurry wall; 3. Ground water treatment by activated carbon; and 4. Gravel-filled recharge trenches. Engineering drawings are found in Volume 3.

Not Available

1989-08-01

324

Electrophoretic Mobilities and Cation Exchange Capacities of Florida Phosphate Slimes.  

National Technical Information Service (NTIS)

The report discusses the investigation of the dewatering of waste phosphatic slimes. This was done by studying electrophoretic mobility and cation exchange of the slimes. The mobilities and exchange capacities are reported for samples of slimes taken from...

A. May

1975-01-01

325

Underwater Subsurface Injected Canal Sealants -- Lower Cost Canal Lining Program and Soil and Moisture Conservation Program.  

National Technical Information Service (NTIS)

A method of reducing canal seepage by injecting an asphalt emulsion under the soil surface was investigated. This technique is intended for use in unlined canals with water delivery commitments which would not allow dewatering for conventional lining cons...

B. V. Jones

1966-01-01

326

46 CFR 122.512 - Recommended emergency instructions format.  

Code of Federal Regulations, 2012 CFR

...dry to prevent loss of stability due to water in bilges. Use power driven bilge pump, hand pump, and buckets to dewater. ...if installed. (v) Maneuver vessel to minimize effect of wind on fire. (vi) If unable to control fire,...

2012-10-01

327

Determination/Validation of Technologies for Treatment/Recycle of Contaminated Sludges: Phase 2 - Field Tests.  

National Technical Information Service (NTIS)

The Air Force Air Logistics Centers (AF-ALCs) generate large quantities of sludges from their industrial wastewater treatment plants (IWTPs). This report covers the Phase I field tests for: dewatering by flocculation and filtration; metals removal by Liqu...

T. Werner S. Chauhan B. Monzyk D. Folsom N. Conkle

1998-01-01

328

30 CFR 784.25 - Return of coal processing waste to abandoned underground workings.  

Code of Federal Regulations, 2013 CFR

...filled, method of constructing underground retaining walls, influence of the backfilling operation on active underground mine operations...applicant shall describe the source of the hydraulic transport mediums, method of dewatering the placed backfill, retainment...

2013-07-01

329

40 CFR 721.8965 - 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-.  

Code of Federal Regulations, 2013 CFR

...3)(ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene/styrene), and (g)(5). (iii) Industrial, commercial, and consumer activities. Requirements as...

2013-07-01

330

Evaluation of Damage Control Tactics and Equipment. Phase II. Baseline Tests.  

National Technical Information Service (NTIS)

This report summarizes results from the second baseline series of damage control tests involving pipe patching, shoring, dewatering, and hull repair. In pipe patching, the EWARP patch was more effective on isolated (non-pressurized) systems than the soft ...

S. A. Hill C. Campbell H. Kuzma F. W. Williams

1996-01-01

331

Rotary Precoat Filtration of Sludge From Acid Mine Drainage Neutralization.  

National Technical Information Service (NTIS)

A two year study was conducted at 4 locations in Pennsylvania to test the effect of various alkalies and filter aids on rotary vacuum precoat filtration for dewatering of lime neutralization sludge. The process consisted of neutralization, aeration, sedim...

T. S. Brown

1971-01-01

332

40 CFR 435.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

Code of Federal Regulations, 2010 CFR

...maximum in the stock barite. Non-aqueous drilling fluids and dewatering...Drill cuttings associated with non-aqueous drilling fluids No discharge...drill cuttings associated with non-aqueous drilling fluids for...

2009-01-01

333

28. Pump Room interiorMain valve control panel with status indicators ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. Pump Room interior-Main valve control panel with status indicators for main flooding/dewatering valves and gates. - Hunters Point Naval Shipyard, Drydock No. 4, San Francisco, San Francisco County, CA

334

WASTE ACTIVATED SLUDGE PROCESSING  

EPA Science Inventory

A study was made at pilot scale of a variety of processes for dewatering and stabilization of waste activated sludge from a pure oxygen activated sludge system. Processes evaluated included gravity thickening, dissolved air flotation thickening, basket centrifugation, scroll cent...

335

SLUDGE TREATMENT AND DISPOSAL. VOLUME 1. SLUDGE TREATMENT  

EPA Science Inventory

This two volume set presents in detail technical design information for the following sludge treatment and disposal processes: lime stabilization, anaerobic digestion, aerobic digestion, thermal sludge conditioning, thickening, dewatering, and landfilling. The discussion of each ...

336

40 CFR 435.45 - Standards of performance for new sources (NSPS).  

Code of Federal Regulations, 2013 CFR

...Produced Water: (A) All coastal areas except Cook Inlet No discharge. (B) Cook Inlet Oil & Grease The maximum for any one...Dewatering Effluent: 1 (A) All coastal areas except Cook Inlet No discharge. (B) Cook Inlet:...

2013-07-01

337

Handling and Disposal of Sludges from Combined Sewer Overflow Treatment. Phase III - Treatability Studies.  

National Technical Information Service (NTIS)

This report documents the results of a project initiated to evaluate the handling and disposal of combined sewer overflow (CSO) treatment residuals. Bench scale thickening and pilot and full-scale centrifugation dewatering tests were performed at dry-weat...

R. Osantowski A. Geinopolos R. E. Wullschleger M. J. Clark

1977-01-01

338

Benefits of Using Remotely Operated Vehicles to Inspect USACE Navigation Structures.  

National Technical Information Service (NTIS)

The U.S. Army Corps of Engineers operates numerous navigation locks and dams across the country. Age and lack of funds to maintain these structures has led to significant increases in unscheduled outages. Dewatering provides the best inspection opportunit...

G. E. Phetteplace J. C. Weale J. H. Lever

2007-01-01

339

Viscous effects in the acoustic manipulation of algae for biofuel production  

Microsoft Academic Search

Microalgae are emerging as a promising source for environmentally friendly biofuels. Acoustic manipulation of algal cells\\u000a using standing waves is a relatively new method for dewatering and\\/or sorting algae harvests. Recent work in the field has\\u000a shown that acoustic dewatering methods may be more efficient and economical than traditional methods. Optimization of acoustic\\u000a algal cell manipulation requires a knowledge of

Cara A. C. Leckey; Mark K. Hinders

340

Alternative fuel comprised of sewage sludge and a liquid hydrocarbon fuel oil  

SciTech Connect

An improved fuel composition is provided comprising in minor proportion a non-dewatered sewage sludge and in major proportion an organic fuel comprised of a hydrocarbon fuel oil. A method is also provided for the incineration of sewage sludge comprised of providing an admixture of a minor proportion of a non-dewatered sewage sludge and a major proportion of an organic fuel comprised of a liquid hydrocarbon fuel oil and incinerating the admixture.

Ashworth, R. A.

1985-12-24

341

The engineering-geological evaluation of sites proposed for development in the dolomite karst regions of Southern Africa  

NASA Astrophysics Data System (ADS)

In the Transvaal Province of the Republic of South Africa, engineering-geological investigations of sites proposed for development are required by law. The investigation produced is depicted on a flowchart. Flowcharts are provided to serve as guidelines in the evaluation of dewatered and non-dewatered sites. The evaluation of dolomitic sites culminates in a 3-fold categorization of the suitability of the site for development. Precautionary measures that are compulsory for development are listed.

Roux, Paul

1988-10-01

342

Operating and maintenance guidelines for screenbowl centrifuges  

SciTech Connect

Plant dewatering circuits equipped with screenbowl centrifuges need to be well designed, properly operated, and adequately maintained to maximize the dewatering performance. The most important 'feed variables' are particle size, dry solids feed rate and slurry flow rate. The most important 'machine variables' include pool depth, rotational speed and gearbox ratio. The article discusses the effect of these parameters and offers some maintenance guidelines. The article was adapted from a paper presented at CoalPrep 2008. 6 refs., 2 figs., 2 tabs.

Jahnig, W.S.R.; Bratton, R.; Luttrell, G. [Decanter Machine, Johnson City, TN (United States)

2009-01-15

343

Pore destruction resulting from mechanical thermal expression  

SciTech Connect

Mechanical thermal expression (MTE) is a dewatering technology ideally suited for the dewatering of internally porous biomaterials. For such materials, the combined application of temperature and compressive force in the MTE process enhances the collapse of the porous structure, resulting in effective water removal. In this article, a comparison of the dewatering of titanium dioxide, which is an ideal incompressible, non-porous material, and lignite, which is a porous plant-based biomaterial, is presented. The comparison is based on the parameters critical to dewatering, namely the material compressibility and the permeability. With the aid of mercury porosimetry results, a detailed discussion of the pore destruction of lignite resulting from MTE processing is presented. It is illustrated that there is a well-defined relationship between the pore size distribution after MTE dewatering and the MTE temperature and pressure. The discussion is extended to an investigation of the effects of MTE processing conditions on the effective and noneffective porosity. The effective porosity is defined as the interconnected porosity, which contributes to flow through the compressed matrix, while the non-effective porosity is the remaining porosity, which does not contribute to flow. It is illustrated that there is a linear relationship in both the effective and non-effective porosity with the total porosity. The linear relationship is independent of the processing conditions. It is also shown that MTE processing collapses the effective and non-effective pores at roughly the same rate.

Clayton, S.A.; Wheeler, R.A.; Hoadley, A.F.A. [Monash University, Clayton, Vic. (Australia)

2007-07-01

344

Engineering development of selective agglomeration. Site closeout report  

SciTech Connect

The Selective Agglomeration POC facility consisted of a coal crushing and grinding circuit, followed by an agglomeration circuit and product dewatering. (A plot plan of the facility is shown in Figure 1-2.) The coal crushing and grinding system consisted of a hammermill coal crusher, weigh-belt feeder, two ball mills (primary and secondary), and necessary hoppers, pumps, and conveyors. The mills were capable of providing coal over a range of grinds from a d{sub 50} of 125 to 25 microns. Slurry discharged from the ball mills was pumped to the agglomeration circuit. The agglomeration circuit began with a high-shear mixer, where diesel was added to the slurry to begin the formation of microagglomerates. The high-shear mixer was followed by two stages of conventional flotation cells for microagglomerate recovery. The second-stage-flotation-cell product was pumped to either a rotary-drum vacuum filter or a high-G centrifuge for dewatering. The dewatered product was then convoyed to the product pad from which dump trucks were used to transfer it to the utility plant located next to the facility. Plant tailings were pumped to the water clarifier for thickening and then dewatered in plate-and-frame filter presses. These dewatered tailings were also removed to the utility via dump truck. Clarified water (thickener overflow) was recycled to the process via a head tank.

Not Available

1993-04-01

345

Use of drainability and filterability simulations for evaluation of oxidative treatment and polymer conditioning of sludge.  

PubMed

In the traditional view of sludge structure, a two-phase system is visualized. The solid phase is often illustrated as consisting of uniform, spherical, negatively charged particles. This simplistic picture limits the understanding of both conditioning and dewatering. Specifically, it limits us to only two strategies for destabiiization: charge neutralization (using cationic coagulant species with either uniform or patch effects), and bridging (using polymeric flocculants). In fact, the situation is more complex in many respects. In this paper, we compared chemical conditioning of anaerobically digested biosolids using (1) conventional polymeric flocculation, and (2) treatment by chemical oxidants. Since these strategies may alter dewatering behavior by very different mechanisms, we report comparisons using a lab-scale simulator of belt press dewatering, including separate steps for the drainage and filtration processes. This allows greater insight into the effects of these conditioning methods and how they might be properly employed. PMID:15580989

Ayol, A; Dentel, S K; Filibeli, A

2004-01-01

346

Improving the assessment of risk from pathogens in biosolids: fecal coliform regrowth, survival, enumeration, and assessment.  

PubMed

Reactivation or regrowth of fecal coliform bacteria in biosolids has recently become a concern due to knowledge that Class B materials may fail to meet this criterion after storage or even after land application. In this paper, data show the two types of fecal coliform increases that have been characterized: immediate reappearance of large concentrations directly after dewatering; and the rapid, but less immediate, increases that follow dewatering with some biosolids after dewatering. The latter phenomenon is shown to extend over a time period of days prior to gradual decrease in fecal coliform numbers. Modeling shows that anaerobic or fermentative growth cannot simulate the observed growth, but that a straightforward biokinetic model can duplicate the observed conditions if a doubling time of one hour is assumed, which is supported by literature. Thus regrowth cannot be ruled out as the underlying phenomenon. PMID:18235170

Dentel, S K; Qi, Y; Herson, D S

2008-01-01

347

Results from using the CSAMT technique to monitor the Tono UCG experiment  

SciTech Connect

The controlled source audio-frequency magnetotelluric (CSAMT) surface electromagnetic geophysical technique was used to monitor the Tono project partial seam CRIP UCG (controlled retracting injection point underground gasification) test conducted on the WIDCO mine property near Centralia, Washington. The results of the monitoring show a changing resistivity pattern with time indicative of a changing process. The process boundary determined using the CSAMT technique agrees very well with the process boundary determined from the limited thermal data coupled with the mass balance calculations and post-test coring. The CSAMT measured resistivities respond to the movement of water during dewatering. The dewatering boundary appears to be influenced by geologic barriers such as faults and fractures and the dewatering boundary appears to determine the ultimate process boundary.

Bartel, L.C.; Davidson, G.S.; Jacobson, R.D.; Uhl, J.E.

1985-01-01

348

Evaluation of infrasound and strobe lights for redistributing migrant salmon smolts in the McNary Juvenile Bypass: 1997. Final report  

SciTech Connect

The authors assessed the use of infrasound and strobe lights for redistributing yearling and subyearling migrant salmonids away from dewatering screens in the McNary Juvenile Bypass System. Infrasound signals were generated using two devices: a pump with a rotary valve and reciprocating pistons. They evaluated the former device operating at 20 Hz in spring based upon differences in mean counts of migrant smolts across the channel during hourly sound-on and sound-off treatments (-on = 20). They evaluated the piston device operating at about 8 Hz in summer based on differences in mean counts of migrant smolts near the side dewatering screen during hourly sound-on and sound-off treatments (-on = 9). They also tested three separate strobe light applications. In spring, they initially installed one strobe head (Flash Technologies AGL Series) in midchannel at the elevation of the top screen panels and aimed it toward the screened wall. Later in the spring, they deployed two strobe heads on the screened wall 4.3 and 7.3 m upchannel, respectively, from the downstream edge of the side dewatering screens. The authors evaluated effectiveness by comparing mean counts of migrant smolts across the channel during hourly strobe-on and strobe-off treatments (-on = 18 for both applications). In summer, they installed two strobe heads behind the dewatering screens 7.3 and 11 m upchannel, respectively, from the downstream edge of the side dewatering screens. They evaluated performance based on differences in mean counts of smolts near the side dewatering screen during hourly sound-on and sound-off treatments.

Johnson, P.N.; Ploskey, G.R.

1998-12-01

349

Sludge treatment reed bed facilities--organic load and operation problems.  

PubMed

The dewatering of the sludge with loss on ignition between 50 and 65% will have a maximal drainage on the order of 0.008-0.020 L/s/m(2). Dewatering of the sludge with loss of ignition higher than 65% of dry solids will have a maximal drainage on the order of only 0.001-0.004 L/s/m(2), approximately five to 10 times lower. It can be seen that there is a tendency for the achievable dewatering result to increase with the decrease of loss on ignition or fat in the feed sludge. The correlation shows that if the loss of ignition is higher than 65% of dry solids in the feed sludge the dewatering results in approximately 10% dry solid or lower in the sludge residue, and in approximately 5% dry solid or lower in the sludge residue if the fat concentration is above 10,000 mg/kg ds in the feed sludge. In systems treating sludge with high contents of fat (15,000-30,000 mg/kg ds) and oil (2,300-7,000 mg/kg ds) and if the loss of ignition is higher than 65% (between 65-76%) the dewatering efficiencies only achieve 5-15% dry solid in the sludge residue. In systems treating sludge with low contents of fat (4,000-8,000 mg/kg ds) and oil (50-2,000 mg/kg ds) and with loss on ignition between 50-65% contents of organic solids the dewatering efficiencies achieve 20-37% dry solid in the sludge residue. PMID:21411944

Nielsen, Steen

2011-01-01

350

The measurement of water transport in porous materials using impedance spectroscopy  

NASA Astrophysics Data System (ADS)

This paper describes the application of electrical measurements to monitor the extraction (movement of water from the mortar) of water from calcium lime, natural hydraulic lime and Portland cement mortars placed on an adsorbent brick substrate. Impedance measurements were used to identify the changes in bulk resistance of the mortar. A model has been developed combining sharp front theory and Boltzmann's distribution law of statistical thermodynamics to identify the point at which no further absorption of water into the brick occurs. A linear relationship was found between the exponential of bulk resistance and the square root of time during dewatering. A change in gradient was attributed to the end of dewatering.

Ball, R. J.; Allen, G. C.

2010-03-01

351

AIR POLLUTION CONTROL - PRACTICAL EXPERIENCE AT TONGAAT  

Microsoft Academic Search

Experiences at the 'Tongaat Factory with six high efficiency wet type flue gas scrubbe:rs are described. The experiences relate to three different types of scrubbers and to both single fuel (bagasse) and dual fuel jcoal\\/bagasse) boilers.' Aspects covered include pollution control equipment selection, operation and performance, materials of construction, wet and dry fans, smuts dewatering and conveying and the disposal

C. MOOR

352

Fourth technical contractors' conference on peat  

SciTech Connect

This conference reported the status of the US Department of Energy Peat Program. The papers presented dealt with peat dewatering, international peat programs, environmental and socio-economic factors, peat gasification, peat harvesting, and the state peat surveys for 14 states. Separate abstracts were prepared for the individual papers. (CKK)

Not Available

1981-01-01

353

77 FR 67777 - National Oil and Hazardous Substance Pollution Contingency Plan; National Priorities List...  

Federal Register 2010, 2011, 2012, 2013

...regulations.gov, your email address will...recommends that you include your name and other contact information in the body of your comment and with any...deletion will not take effect. EPA will, as...municipal garbage dump, liquid waste dewatering...

2012-11-14

354

Boron Isotopic Compositions of Mud Volcano Fluids in Taiwan Accretionary Prism  

Microsoft Academic Search

Boron and B isotopes are sensitive diagnostic tracers of sediment de-watering in subduction zones. More than 20 mud volcano fluids collected along two major geological structures, the Chishan fault (CHF) and the Gutingkeng anticline (GTKA), in the southwestern Taiwan were analyzed for B and d11B, as well as other geochemical constituents. These fluids are characterized by high chloride contents, up

C. You; M. Li; C. Chung; K. Huang

2001-01-01

355

Changes of groundwater chemistry caused by the flooding of iron mines (Czestochowa Region, Southern Poland)  

Microsoft Academic Search

Underground mining always causes disturbances of the hydrogeological environment, primarily due to the dewatering of mine workings. The flooding of abandoned mines contributes to the rebound of the cone of depression developed previously, but it also leads to significant pollution of groundwater in the mined areas. The Middle Jurassic aquifer in the Czestochowa region of the flooded iron mines has

L. Razowska

2001-01-01

356

Modeling water and sediment contamination of Lake Pontchartrain following pump-out of Hurricane Katrina floodwater  

Microsoft Academic Search

Levee failure and overtopping as a result of Hurricane Katrina caused major flooding of New Orleans, Louisiana. Floodwaters, which were contaminated with heavy metals, organic chemicals, and fecal coliform bacteria (FCB), were pumped into neighboring Lake Pontchartrain during dewatering. The impact of levee failure on water and benthic sediment concentrations in the lake was investigated by applying a numerical water

Mark S. Dortch; Mansour Zakikhani; Sung-Chan Kim; Jeffery A. Steevens

2008-01-01

357

A novel implementation of water recovery from whey: “forward–reverse osmosis” integrated membrane system  

Microsoft Academic Search

As a result of its emerging contribution to water recovery and clean water production, forward osmosis (FO) in integrated membrane system has recently especially been preferred by research communities on membrane science and desalination technology. In this study, the effectiveness of FO reverse osmosis (RO) integrated membrane system in whey dewatering was investigated in laboratory scale experiments in which FO

Coskun Aydiner; Semra Topcu; Caner Tortop; Ferihan Kuvvet; Didem Ekinci; Nadir Dizge; Bulent Keskinler

2012-01-01

358

Stream Fragmentation Thresholds for a Reproductive Guild of Great Plains Fishes  

Microsoft Academic Search

Impoundments, diversion dams, and stream dewatering have created a mosaic of large river fragments throughout the Great Plains of central North America. Coincident with these habitat changes are massive declines in the distribution and abundance of Great Plains fishes belonging to the “pelagic-spawning” reproductive guild. We analyzed longitudinal fragment lengths (measured in river kilometers, rkm) and literature accounts of population

Joshuah S. Perkin; Keith B. Gido

2011-01-01

359

An evaluation of technologies for the heavy metal remediation of dredged sediments  

Microsoft Academic Search

Sediments dewatering is frequently necessary after dredging to remediate and treat contaminants. Methods include draining of the water in lagoons with or without coagulants and flocculants, or using presses or centrifuges. Treatment methods are similar to those used for soil and include pretreatment, physical separation, thermal processes, biological decontamination, stabilization\\/solidification and washing. However, compared to soil treatment, few remediation techniques

Catherine N. Mulligan; Raymond N. Yong; Bernard F. Gibbs

2001-01-01

360

Coal-water slurries  

Microsoft Academic Search

Coal slurries using oil, methanol, or water could reduce the transportation costs that are one of the barriers to industrial and power-plant coal conversion. New coal-water slurry (CWS) technology eliminates the need for oil and the need to dewater before burning. Studies show that a CWS pipeline would be increasingly competitive with rail transport in the Southeast because pipelines are

Dunlop

2009-01-01

361

A modeling assessment of the thermal regime for an urban sport fishery  

Microsoft Academic Search

Water temperature is almost certainly a limiting factor in the maintenance of a self-sustaining rainbow trout ( Oncorhynchus mykiss, formerly Salmo gairdneri) and brown trout ( Salmo trutta) fishery in the lower reaches of the Cache la Poudre River near Fort Collins, Colorado, USA. Irrigation diversions dewater portions of the river, but cold reservoir releases moderate water temperatures during some

John M. Bartholow

1991-01-01

362

TRANSPORT OF SEWAGE SLUDGE  

EPA Science Inventory

This project was initiated with the overall objective of developing organized information pertaining to the costs of various sewage sludge transport systems. Transport of liquid and dewatered sludge by truck and rail and liquid sludge by barge and pipeline is included. The report...

363

Belt Filtration. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.  

ERIC Educational Resources Information Center

This lesson, an introduction to belt management, was developed for a course in sludge treatment and disposal. Fundamental principles of belt filter operation are described. Chemical conditioning and the effect on sludge characteristics are discussed, and a detailed description of the different zones of dewatering is presented. Information on…

Broste, Dale

364

77 FR 810 - Petitions for Modification of Application of Existing Mandatory Safety Standards  

Federal Register 2010, 2011, 2012, 2013

...required to de-water the work area. (4) All up-pitch workings of moderate to steep pitch are accessed only through ladders making the carrying...petitioner states that: (1) Due to the steep pitch encountered in mining anthracite coal veins,...

2012-01-06

365

78 FR 59066 - Petitions for Modification of Application of Existing Mandatory Safety Standards  

Federal Register 2010, 2011, 2012, 2013

...required to de-water the work area. (4) All up-pitch workings of moderate to steep pitch are accessed only through ladders making the carrying...petitioner states that: (1) Due to the steep pitch encountered in mining anthracite coal veins,...

2013-09-25

366

Pure oxygen treatment of pesticide plant waste water  

Microsoft Academic Search

Chemagro's waste water treatment plant, which includes pH control, solids removal, equalization, biological treatment (UNOX) and sludge dewatering process units, and which reduces COD by 50.4%, BOD by 92.8%, and phenols by 76.9% is discussed, including the operating problems, operating experience with both the cyrogenic air separation plant and the UNOX system, and advantages.

Pallanich

1978-01-01

367

Carboxylic acid sorption regeneration process  

DOEpatents

Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine.

King, C. Judson (Kensington, CA); Poole, Loree J. (Baton Rouge, LA)

1995-01-01

368

Enzyme Activities in a Sandy Soil Amended with Sewage Sludge and Coal Fly Ash  

Microsoft Academic Search

Previous studies showed that coal fly ash could stabilize sewage sludge by reducing metal availability, but fly ash may cause an adverse effect on soil microbial activities. Therefore, an experiment was performed to evaluate the effects of amendment of soil with anaerobically digested dewatered sewage sludge, stabilised with alkaline coal fly ash, on soil enzyme activity and the implications for

K. M. Lai; D. Y. Ye; J. W. C. Wong

1999-01-01

369

Underwater terrain mapping of dam stilling basins  

Microsoft Academic Search

The high-resolution acoustic mapping (HRAM) system was developed in response to a stated need by the United States Army Corps of Engineers to evaluate the floor of a navigation lock that could not be dewatered. Navigation Lock #26 on the Mississippi River was constructed on piles and mats over a sandy bottom. Over the years the footings had shifted, probably

Ted O. Price

1995-01-01

370

Modelling module of the intelligent control system for the variable volume pressure filter  

Microsoft Academic Search

Artificial Intelligence methods like expert systems, fuzzy logic and neural networks have proved to be excellent tools for the control of mineral processes. This technology is currently being embedded directly into process equipment like flotation cells and dewatering filters. This paper presents the modelling module for a pressure filter. The modelling module of the intelligent system predicts filtration using the

Sirkka Liisa Jämsä-Jounela; Marja Oja

2000-01-01

371

Analytical and experimental system studies of combined photovoltaic\\/thermal systems. Technical status report No. 11, November 1980January 1981  

Microsoft Academic Search

Program progress is indicated on a Milestone Chart, and a monthly history of the funds expended is given. Technical progress includes computer simulation studies of photovoltaic\\/thermal systems in industrial process heat applications including: crude oil dewatering; aluminum container manufacturing; bread and bun bakery; and meat processing. Other progress reported includes PV\\/T concentrating collector procurement, participation in national standards development, and

D. W. Hooker; E. K. May; R. E. West

1981-01-01

372

Alcohol production from fermentation of sweet potatoes  

SciTech Connect

A study was conducted to determine the ethanol production characteristics of sweet potatoes. Ethanol yields were as high as 137 liters per tonne of feedstock using procedures developed for grain. Major problems encountered were low ethanol concentrations in the beer and poor stillage dewatering properties.

Egg, R.P.; Coble, C.G.; O'Neal, H.P.; Sweeten, J.M.

1982-12-01

373

Evidence of vivianite in FeSO 4-flocculated sludges  

Microsoft Academic Search

Precipitation of sludges with ferrous iron salts can increase the total phosphorus content of sludges. However, the forms of phosphorus thus precipitated have never been directly investigated. Three dewatered urban sewage sludges were sampled from wastewater treatment plants performing dephosphatation with the addition of FeSO4 (two anaerobically digested sludges and an activated sludge). Phosphorus species in sludges were investigated by

E. Frossard; J. P. Bauer; F. Lothe

1997-01-01

374

Human Enteropathogen Load in Activated Sewage Sludge and Corresponding Sewage Sludge End Products?  

PubMed Central

This study demonstrated a significant reduction in the concentrations of Cryptosporidium parvum and Cryptosporidium hominis oocysts, Giardia lamblia cysts, and spores of human-virulent microsporidia in dewatered and biologically stabilized sewage sludge cake end products compared to those of the respective pathogens in the corresponding samples collected during the sludge activation process.

Graczyk, Thaddeus K.; Lucy, Frances E.; Tamang, Leena; Miraflor, Allen

2007-01-01

375

Pilot-scale peroxidation (H 2O 2) of sewage sludge  

Microsoft Academic Search

Municipal and industrial wastewater treatment plants produce large amounts of sludge. This excess sludge is an inevitable drawback inherent to the waste activated sludge process. Both the reduction of the amount of sludge produced and improving its dewaterability are of paramount importance. Novel pre-treatment processes have been developed in order to improve sludge dewatering, handling and disposal. This paper discusses

E. Neyens; J. Baeyens; M. Weemaes; B. De heyder

2003-01-01

376

RECLAMATION OF ALUMINUM FINISHING SLUDGES  

EPA Science Inventory

The research study of the reclamation of aluminum-anodizing sludges was conducted in two sequential phases focused on enhanced dewatering of aluminum-anodizing sludges to produce commercial-strength solutions of aluminum sulfate, i.e., liquid alum. The use of high-pressure (14 to...

377

Paleoecology of a >90,000-year lacustrine sequence from Fog Lake, Baffin Island, Arctic Canada  

Microsoft Academic Search

A 137cm sediment core from Fog Lake, a small upland basin that was not glaciated during the Late Wisconsinan, reveals the following stratigraphic succession: (I) basal diamicton, (II) laminated silts, (III) compacted dewatered gyttja, (IV) stratified minerogenic sediments, and (V) overlying gyttja. Units I–III, and most of unit IV, were deposited prior to the Holocene; unit V represents approximately the

Alexander P. Wolfe; Bianca Fréchette; Pierre J. H. Richard; Gifford H Miller; Steven L Forman

2000-01-01

378

Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6  

SciTech Connect

The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.

W. E. Remsen

2006-12-19

379

GROUNDWATER FLOW MODELLING APPLICATIONS IN MINING HYDROGEOLOGY  

Microsoft Academic Search

In the presented paper some specific features and problems of numerical modelling applications in mining environment are briefly discussed. The issues discussed are documented by three modelling case studies. Two of the applications are aimed at mine dewatering problems in active coal mines. The first represents the underground hard coal mining region in the Czech part of the Upper Silesian

Nadia Rapantová; Arnost Grmela; David Vojtek; Josef Halir; Bedrich Michalek

380

EMISSION OF METALS AND ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS - VOLUME V: SITE 3 FINAL EMISSION TEST REPORT  

EPA Science Inventory

The Site 3 plant treats 2.5 MGD (designed for 7.5 MAD) of municipal wastewater. he blended primary/secondary sludge is dewatered using 2 belt filter presses to about 22 to 24 percent solids. ludge is fed to a fluidized bed incinerator which is designed to burn 2.75 dry tons per h...

381

Improving the assessment of risk from pathogens in biosolids: fecal coliform regrowth, survival, enumeration, and assessment  

Microsoft Academic Search

Reactivation or regrowth of fecal coliform bacteria in biosolids has recently become a concern due to knowledge that Class B materials may fail to meet this criterion after storage or even after land application. In this paper, data show the two types of fecal coliform increases that have been characterized: immediate reappearance of large concentrations directly after dewatering; and the

S. K. Dentel; Y. Qi; D. S. Herson

2008-01-01

382

Overview assessment of nuclear-waste management  

Microsoft Academic Search

The environmental control technologies associated with Department of Energy nuclear waste management programs were reviewed and the most urgent problems requiring further action or follow up were identified. In order of decreasing importance they are: (1) shallow land disposal technology development; (2) active uranium mill tailings piles; (3) uranium mine dewatering; (4) site decommissioning; (5) exhumation\\/treatment of transuranic waste at

B. W. Burton; V. P. Gutschick; B. A.. Perkins; C. L. Reynolds; J. C. Rodgers; J. G. Steger; T. K. Thompson; L. K. Trocki; E. M. Wewerka; M. L. Wheeler

1982-01-01

383

Influence of structural properties of alum and ferric flocs on sludge dewaterability  

Microsoft Academic Search

Sludges are made of flocs produced during the coagulation stage. Their dewatering not only depends on the equipment used but also on the chemical, structural and physical characteristics of flocs. In this study, the relation between floc structure and sludge dewaterability is investigated beside the influence of the operating conditions during coagulation. Eight synthetic clay flocs families are produced using

Christelle Turchiuli; Claire Fargues

2004-01-01

384

Sizing residuals drying beds  

Microsoft Academic Search

Design criteria were developed for nonmechanical dewatering of water treatment residuals. First, certain physical properties were determined for residuals high in alum, ferric chloride, or polyaluminum chloride. Laboratory tests that characterized these properties showed that capillary suction time and time to filter correlated very well; either could be used in the laboratory to test residuals' drainage characteristics. Pilot- and full-scale

David A. Cornwell; Carel Vandermeyden

1999-01-01

385

NITROGEN LOSS DURING SOLAR DRYING OF BIOSOLIDS  

Microsoft Academic Search

Solar drying has been used extensively to dewater biosolids for ease of transportation and to a lesser degree to reduce pathogens prior to land application. The nitrogen in biosolids makes them a relatively inexpensive but valuable source of fertilizer. In this study, nitrogen loss from tilled and untilled biosolids was investigated during the solar drying process. Samples of aerobically and

S. A. OShaughnessy; I. Song; J. F. Artiola; C. Y. Choi

2008-01-01

386

Single cell protein as an occupational hazard  

Microsoft Academic Search

Single cell protein (SCP) intended for animal feed purposes was produced in a pilot plant. The SCP consisted of Methylomonas methanolica, a pseudomonas species which is an obligate methanol user. The SCP was cultured in fermenters and later dewatered and dried in a spray-drier. Seven of eight research workers had febrile reactions 6-12 hours after exposure to SCP dust. All

L Ekenvall; B Dölling; C J Göthe; L Ebbinghaus; L V von Stedingk; J Wasserman

1983-01-01

387

Method for treating oil sands extraction plant tailings  

Microsoft Academic Search

Tailings from an oil sands hot water process extraction plant are mixed with hydrolyzed starch flocculant and transferred to a settling pond. After a residence period on the order of one year, sludge from the lower region of the settling pond is withdrawn, mixed with a hydrolyzed starch dewatering agent and transferred to a collecting pond. After a residence period

Yong

1984-01-01

388

Biological sludge-energy recycling method  

Microsoft Academic Search

A method is described for converting treated sludge into an improved concentrated organic feedstock. The method includes conditioning of sludge with hydrolytic enzymes, the mechanical disintegration of tissue and cell components, the removal of heavy metals, autolysis and dewatering to produce an organic fertilizer or feedstock. Product stabilization for long-term storage is achieved by acidification or addition of granular sorbents.

L. G. Erickson; H. E. Worne

1981-01-01

389

Experimental microwave system for separation of water-oil emulsions  

Microsoft Academic Search

Description of experimental microwave system for dewatering and demineralization oils is presented. It is based on method of allocation of electromagnetic energy in a duct with dissipative medium by heterogeneous coaxial directive structures. These structures are wide-range and permit actualizing of needful allocation of electromagnetic energy in a duct. The purpose of creating of this system - psychical modeling and

T. A. Ayupov; N. G. Vorobiev

2008-01-01

390

Development of an innovative remediation methodology for contaminated soils and sediments using high-energy radiation  

Microsoft Academic Search

The research objectives were to develop and demonstrate a remediation methodology for contaminated soils and sediments using high energy radiation, and develop predictive tools for process simulation. Proposed treatment involves irradiating and dewatering slurries, recycling wash water, and returning clean soil to original location. Extensive literature review of contaminated soils in environment was conducted. Processes affecting removal of contaminants were

Prasad V. Chittaluru

1997-01-01

391

Exploitation of gold in a historic sewage sludge stockpile, Werribee, Australia: resource evaluation, chemical extraction and subsequent utilisation of sludge  

Microsoft Academic Search

Sewage sludges are dewatered end products of human sewage waste and are recognised repositories of organic pollutants and heavy metals. They may be considered targets for economic extraction of Au because of the documented Au content of sewage sludges worldwide which are of the order of some ore deposits currently mined for Au. They are also highly nutrient enriched (nitrogen

Shane J. Reeves; Ian R. Plimer; David Foster

1999-01-01

392

AN ASSESSMENT OF TECHNOLOGY FOR POSSIBLE UTILIZATION OF BAYER PROCESS MUDS  

EPA Science Inventory

The program comprised review of technical literature published from 1940 on subjects related to technology of processing bauxite, the dewatering and impoundment of the mud residues and their possible utilization. Mud samples were received from the domestic alumina plants for char...

393

The relationship between mud volcanoes, petroleum migration and accretionary prisms: Lessons from the Caucasus, the Australian margin and Venezuela  

Microsoft Academic Search

Mud volcanoes have been widely documented in areas of overpressure where explosive expansion of trapped methane has occurred during argillokinesis. In an area with high sedimentation rate, such as the Gulf of Mexico, there may be no time for fine-grained sediment to de-water before being covered by impermeable material. In an accretionary wedge this process is complicated by overthrusting of

Paul Ware

1996-01-01

394

Modern solids control  

SciTech Connect

The concept of modern solids-control system for drilling rigs is introduced and experimentally investigated. The system incorporates a conventional solids-control arrangement followed by a diversion of part of the drilling mud for chemical conditioning and configuration. The dewatering effluent is returned to the mud system makeup-water storage. The dewatered colloidal solids are then stabilized by being mixed with the shaker discharge and the surrounding soils. The system can provide an effective control of colloidal-solids concentration in drilling muds. In can also minimize the volume of drilling waste. The new process was examined in full-scale experiments to evaluate process efficiency and to identify the effects of field installation, operational variables, solids classification before dewatering, dilution, and the stability of the dewatering and its sensitivity to chemical dosage. In the chemical destabilization tests, a successful treatment was found for flowline samples of five different drilling-mud systems. The conceptual design of the modern solids-control system is presented and discussed. This process is also related to conventional solids-control and wastewater treatments.

Wojtanowicz, A.K. (Louisiana State Univ., LA (US))

1988-09-01

395

EMISSION OF METALS AND ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS - VOLUME VII: SITE 4 FINAL EMISSION TEST REPORT APPENDICES  

EPA Science Inventory

The Site 4 plant treats 11 to 12 MGD of wastewater from domestic (80% of influent) and industrial (20% of influent) sources. he treated primary/secondary sludge is dewatered using cloth filter presses to approximately 35 percent solids. he dried filter cakes are incinerated in a ...

396

EMISSION OF METALS AND ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS - VOLUME IV: SITE 2 FINAL EMISSION TEST REPORT APPENDICES  

EPA Science Inventory

The Site 2 plant treats 38 MGD of municipal and to a lesser degree industrial wastewater. he blended primary/secondary sludge (-65-86% primary) is dewatered using centrifugation to about 18 to 25 percent solids. ludge is fed to an eight-hearth incinerator at approximately 7.0 wet...

397

EMISSION OF METALS AND ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS - VOLUME II: SITE 1 FINAL EMISSION TEST REPORT  

EPA Science Inventory

The Site 1 plant treats 36MGD of wastewater and the blended primary/secondary sludge is dewatered to approximately 16 to 2O percent solids. ludge is incinerated by a six-hearth unit at approximately 6.0 wet tons per hour. missions are controlled by a three tray impingement scrubb...

398

Alternative technology for corn milling and high fructose corn syrup production  

Microsoft Academic Search

The production of high fructose corn syrup (HFCS) by the process of corn wet milling requires large volumes of water for the steeping and milling operations. The water, incorporated into various process streams, creates extensive requirements for dewatering, drying, and evaporation, resulting in an energy-intensive process. In order to reduce the overall energy requirements of HFCS production, an alternative process

M. H. Russell; G. T. Tsao

1981-01-01

399

Use of gaslift device in the delivery line of a portable turbopump unit  

Microsoft Academic Search

The auxiliary portable turbopumps (TPs) or turbopump units (TPUs) that are serially produced by the domestic mining and shipbuilding industries are intended for the dewatering of the mine shafts, ship bilges, compartments, and wells. The domestic TPUs are outfitted with centrifugal pumps and single-stage turbodrives. Compressed air is used as the working fluid in the turbine flow path. This air

G. D. Shekun

2007-01-01

400

Mobil tests new flexible sucker-rod system in Hugoton field  

Microsoft Academic Search

For the past 3 y, Mobil Oil Corp. has been testing flexible sucker-rod systems for dewatering gas wells in the Hugoton field. The intent of the system is to provide the strength of conventional rods but to achieve superior corrosion resistance. The ''Flexirod'' system being tested is a joint development of Bethlehem Steel Co. and E. I. duPont de Nemours

1974-01-01

401

Annual Report for Gravity Collection Lysimeter Monitoring Plan – ERDF Cells 5 and 6  

SciTech Connect

The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.

M. L. Proctor

2006-04-04

402

Enhanced stabilisation of sewage sludge through thermal hydrolysis - three years of experience with full scale plant  

Microsoft Academic Search

The first full-scale plant for sludge disintegration through Cambi thermal hydrolysis was started up in Hamar, Norway at the end of 1995. It is the first plant with a new design where sludge is directly heated by live steam. During the last three years the plant worked with an availability of over 99%. Prior to hydrolysis the sludge is dewatered

U. Kepp; I. Machenbach; N. Weisz; O. E. Solheim

403

Vapor–liquid equilibrium in systems (water + organic solvent + salt) at low water concentrations but high ratios of salt to water: experimental results and modeling  

Microsoft Academic Search

Water-free organic solvents are often required in chemical processes. It is common practice to dewater organic solvents by distillation. The operation of such distillation equipment often shows that the design specifications are not met as for example the amount of energy required to remove water to very small concentrations is much higher than expected from reliable data for the vapor–liquid

Günter Uhrig; Xiaoyan Ji; Gerd Maurer

2005-01-01

404

Ecosystem Restoration: A Case Study in the Owens River Gorge, California  

Microsoft Academic Search

In 1991 the Los Angeles Department of Water and Power, in cooperation with Mono County, California, initiated a multiyear effort to restore the Owens River Gorge. The project aims to return the river channel, dewatered for more than 50 years, to a functional riverine-riparian ecosystem capable of supporting healthy brown trout and wildlife populations. The passive, or natural, restoration approach

Mark T. Hill; William S. Platts

1998-01-01

405

Analysis of 4-nonylphenols, phthalates, and polychlorinated biphenyls in soils and biosolids  

Microsoft Academic Search

When sewage sludge is added to agricultural land, organic chemicals contaminants are also added. The fate of these chemicals, particularly those shown to have oestrogenic potential, has received much research and regulatory interest in recent years. A method was developed for the analysis of 4-nonylphenols, phthalates, and PCB congeners in soils, mesophilic anaerobially digested dewatered (MADD) sewage sludge, and MADD

Richard Gibson; Min-Jian Wang; Emma Padgett; Angus J. Beck

2005-01-01

406

Evaluation of single cell protein from pulp mills: laboratory analyses and in vivo digestibility  

Microsoft Academic Search

Single cell protein (SCP) derived from secondary clarifiers of pulp mills is a potential commercial protein supplement in many areas. Samples of SCP were collected from several pulp mills in the Pacific Northwest and evaluated by laboratory procedures. Six in vivo digestion trials were conducted to determine the relative nutritive value of SCP that was dewatered by centrifugation or by

R. O. Kellems; M. S. Aseltine; D. C. Church

1981-01-01

407

Uranium recovery research sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory. Quarterly progress report, January-March 1984  

Microsoft Academic Search

Progress is reported on the following studies dealing with mill tailings: long-term stabilizaton; interim stabilization of mill tailings piles; tailings dewatering techniques; tailings neutralization and other alternatives in immobilizing toxic materials in tailings; evaluation of seepage and leachate transport from tailings disposal facilities; effluent and environmental monitoring methods and equipment and instrument testing; attenuation of radon emissions; assessment of leachate

M. G. Foley; B. E. Opitz; W. J. Deutsch; S. R. Peterson; G. W. Gee; R. J. Serne; J. N. Hartley; V. W. Thomas; D. R. Kalkwarf; W. H. Walters; M. J. Fayer; N. A. Wogman; R. W. Nelson

1984-01-01

408

Uranium recovery research sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory. Quarterly progress report, April-June 1984  

Microsoft Academic Search

Progress is reported on the following studies dealing with mill tailings: long-term stabilization; interim stabilization of mill tailings piles; tailings dewatering techniques; tailings neutralization and other alternatives in immobilizing toxic materials in tailings; evaluation of seepage and leachate transport from tailings disposal facilities; effluent and environmental monitoring methods and equipment and instrument testing; attenuation of radon emissions; assessment of leachate

M. G. Foley; W. J. Deutsch; G. W. Gee; J. N. Hartley; D. R. Kalkwarf; M. J. Fayer; R. W. Nelson; B. E. Opitz; S. R. Peterson; R. J. Serne; V. W. thomas; W. H. Walters; N. A. Wogman

1984-01-01

409

Clogging of filter medium by excess polymer during alum sludge filtration  

Microsoft Academic Search

Lab-scale studies of the conditioning of an alum sludge by an anionic polymer showed that the excess polymer can lead to clogging of the filter medium, thereby increasing its resistance. Tests showed that medium resistance (Rm) behaved as Rm=?e?v in which ? and ? coefficients and V is the volume of filtrate. Standard dewatering theory for the Specific Resistance to

Y. Q. Zhao; E. N. Papavasilopoulos; D. H. Bache

1998-01-01

410

A comparative study of freeze-thaw processes for conditioning wastewater and water treatment sludges  

SciTech Connect

This research effort involved the application of indirect- and direct-contact, freeze-thaw conditioning techniques for improving the dewatering characteristics of both waste water and water treatment sludges. Sludges tested included waste activated sludge, primary sewage sludge, waste activated/primary sewage sludge mixtures and alum sludge. The direct-freeze methods examined were the use of a secondary refrigerant (butane) evaporated in the sludge and the use of gas hydrate or clathrate formation by addition of Freon 12 under appropriate temperature and pressure conditions. Sludges were also frozen solid using indirect freezing methods, thawed and tested for comparative purposes. Particle size distribution and floc density measurements were used to determine changes in particle characteristics; specific resistance values and dewatered dry solids concentration were used to assess dewatering characteristics. Results of direct and indirect-contact, freeze-thaw conditioning were compared to the effects of polymer conditioning. The results indicated that direct-freeze methods do not appear technically or economically competitive with currently accepted conditioning methods. The superior results obtained with the indirect-contact, freeze-thaw process when compared to the direct-contact processes suggested that the extent and rate of freezing may greatly influence the particle characteristics of the conditioned sludge, and thus its dewatering characteristics.

Trahern, P.G.

1989-01-01

411

Evaluation and control of corrosion and encrustation in tube wells of the Indus Plains, West Pakistan  

Microsoft Academic Search

Seepage from rivers and irrigation canals has contributed to waterlogging and soil salinization problems in much of the Indus Plains of W. Pakistan. These problems are being overcome in part by tube-well dewatering and deep leaching of salinized soils. The ground waters described are anaerobic and some are supersaturated with troublesome minerals such as calcium carbonate (calcite) and iron carbonate

F. E. Clarke; I. Barnes

1969-01-01

412

IMPROVING SLUDGE INCINERATION AND VACUUM FILTRATION WITH PULVERIZED COAL  

EPA Science Inventory

The research was aimed at improving the filtration and incineration characteristics of primary activated sludge by the addition of pulverized coal prior to the dewatering step. Various doses of coal were added to the sludge in the range of 0.1 to 0.4 kg coal/kg dry sludge solids....

413

Effect of Idealized Flow Conditions on Retention Aid Performance. 2. Polymer Bridging, Charged Patches, and Charge Neutralization  

Microsoft Academic Search

Retention aids can affect papermaking process efficiency and product quality. The efficiency of these polyelectrolyte treatments may be affected by conditions of flow before and during sheet formation. Four contrasting retention aid systems were compared. Hydrodynamic shear before dewatering decreased the retention efficiency of very-high-mass acrylamide copolymers, consistent with irreversible breakdown of polymeric bridges. Such shear had little effect in

TAWEEWAT TRIPATTHARANAN; MARTIN A. HUBBE; JOHN A. HEITMANN; RICHARD A. VENDITTI

414

Survival of Bacterial Indicator Species and Bacteriophages after Thermal Treatment of Sludge and Sewage  

Microsoft Academic Search

The inactivation of naturally occurring bacterial indicators and bacteriophages by thermal treatment of a dewatered sludge and raw sewage was studied. The sludge was heated at 80°C, and the sewage was heated at 60°C. In both cases phages were significantly more resistant to thermal inactivation than bacterial indicators, with the exception of spores of sulfite-reducing clostridia. Somatic coliphages and phages

L. Moce-Llivina; Maite Muniesa; Hugo Pimenta-Vale; Francisco Lucena; Juan Jofre

2003-01-01

415

Amelioration of garri, a cassava-based fermented food by the inoculation of microorganismssecreting amylase, lysine and linamarase into cassava mash  

Microsoft Academic Search

Lactobacillus delbruckii, L. coryneformis and Saccharomyces sp. were found, among 214 isolates from cassava-processing environments to be the highest producers of linamarase, amylase and lysine. The organisms were inoculated into cassava mash, individually, and with all three mixed together, and fermented un-dewatered for up to 120 h. The quality of garri produced from mash inoculated with a combination of all

N. Okafor; C. Umeh; C. Ibenegbu

1998-01-01

416

Desalting of subsurface water using spiral-wound reverse osmosis (RO) system: technical and economic assessment  

Microsoft Academic Search

Subsurface water rise is a major problem in Kuwait. The impact of this problem is manifested in surface water ponds, cracks in buildings, flooded basements and damaged roads. Dewatering this water of moderate salinity is necessary. Being in an arid area with very limited water resources, treatment and recycling of the subsurface water could be very important to a country

Y. Al-Wazzan; M. Safar; S. Ebrahim; N. Burney; A. Mesri

2002-01-01

417

Subtask 3.16 - Low-Cost Coal-Water Fuel for Entrained-Flow Gasification  

SciTech Connect

The specific objective of this research project is to assess the potential process efficiency and pollution control benefits that may occur by applying the hydrothermal, or hot water-drying, process to low-rank coals as related to entrained-flow gasification systems. Project emphasis is on identifying more efficient coal dewatering and CWF formulation methods prior to gasification. A favorable estimate of incremental cost for integrated hydrothermal drying depends, in part, on increasing the particle size of the feed coal from minus 100 to minus 28 mesh for the purpose of simplifying the slurry concentration process. Two options will be reviewed for dewatering or concentrating the processed slurry: (1) repressurization and then concentration with sieve bends or (2) partial dewatering at system pressure with hydroclones. Both have their own merits, sieve bends being a low-cost alternative, while hydroclone application would not require additional pumping sections prior to gasification. Various CWF samples with different particle-size distributions and solids concentrations will be sent to equipment vendors for application review. Also, EERC cost models will be used to calculate the integral cost of adding the partial dewatering to the hydrothermal technology for a commercial-size facility.

Anderson, C.M.

1997-10-01

418

CALCIUM SULFITE CRYSTAL SIZING STUDIES  

EPA Science Inventory

The report describes a reliable experimental method that can be used routinely to determine the crystal size distribution function, a measure that is required for a mathematical representation of the nucleation and growth processes involved in the settling, dewatering, and dispos...

419

Influence of flotation tailings thickening on centrifugal flocculation performance  

Microsoft Academic Search

The dewatering and utilization of coal-cleaning wastes are important problems in connection with the control of air and water pollution in industrial areas and the recycling of production wastes in general. The most intractable technical problem is how to treat the very finely divided suspensions of flotation tailings to recover clean water for recycling and a handleable sludge. Centrifugal flocculation

V. V. Lyadov; A. V. Mikhailenkova; N. I. Yavorskaya; L. M. Gribova; A. V. Kovalchuk

1978-01-01

420

Influence of surfactants on filter cake parameters during vacuum filtration of flocculated iron ore sludge  

Microsoft Academic Search

The influence of certain surfactants on the dewatering of fine iron ore sludge flocculated with anionic flocculants has been investigated in a laboratory-scale vacuum filtration unit. The filtration data have been used in calculating the cake parameters from an integrated form of Darcy's law. A narrow concentration range of surfactant enables reduction of the specific cake resistance and an enhanced

L. Besra; B. P. Singh; P. S. R. Reddy; D. K. Sengupta

1998-01-01

421

Flocculation in Paper and Pulp Mill Sludge Process  

Microsoft Academic Search

The flocculation of activated sludge is an active process and depends upon physical, chemical and biological factors. The basis of activated sludge floc formation lies in the abilities of micro-organisms to stick to each other and to nonbiological particles. Flocculation is an important phenomenon in the sludge process. Well flocculated sludge settles better, is easier to dewater and leads to

Hakkarainen Katja; Sillanpää Mika

422

Removal of DEHP in composting and aeration of sewage sludge  

Microsoft Academic Search

The potential of composting and aeration to remove bis(2-ethylhexyl) phthalate (DEHP) from municipal sewage sludge was studied with two dewatered sludges: raw sludge and anaerobically digested sludge. Composting removed 58% of the DEHP content of the raw sludge and 34% of that of the anaerobically digested sludge during 85 days stabilisation in compost bins. A similar removal for the anaerobically

Sanna K Marttinen; Kari Hänninen; Jukka A Rintala

2004-01-01

423

Moisture readsorption and low temperature oxidation characteristics of upgraded low rank coal  

Microsoft Academic Search

This study investigated the behavior of upgraded low rank coal produced by a coal–oil slurry dewatering process regarding moisture readsorption, low temperature oxidation, and spontaneous combustion. The upgraded low rank coal had higher heating values than raw coal. It also showed lower moisture readsorption than raw coal and had less susceptibility to low temperature oxidation and spontaneous combustion. This seemed

Hokyung Choi; Chinnasamy Thiruppathiraja; Sangdo Kim; Youngjoon Rhim; Jeonghwan Lim; Sihyun Lee

2011-01-01

424

POC-scale testing of an advanced equipment/technology. Quarterly technical progress report No. 1, October--December 1994  

SciTech Connect

The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the University of Kentucky Center for Applied Energy Research (UKCAER) will be evaluated using vacuum, centrifuge, and hyperbaric filtration systems. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals. The project team met with the DOE project management representatives at the Pittsburgh Energy Technology Center on November 18, 1994 to review project plans. After review and comments provided by the DOE, the Project Management and Work Plans were issued on December 15, 1994. The project team held a meeting at the Powell Mountain Coal Company Mayflower Preparation Plant to discuss the strategy on installation and operation of the various dewatering units. Samples of the low sulfur and high sulfur clean coal froths were collected and shipped to UKCAER and Andritz Ruthner Inc.

Groppo, J.G.; Parekh, B.K.

1995-01-30

425

Potential Ground Water Pollution from Sewage Sludge Application on Agricultural Land.  

National Technical Information Service (NTIS)

Corn for silage was grown for three years on land treated with either annual applications or a single application of limed, dewatered sewage sludge at six rates of application. Yields of silage, heavy metal uptake, soil heavy metals, soil nitrates and soi...

R. W. Wengel G. F. Griffin

1979-01-01

426

A study of dual polymer conditioning of aluminum-based drinking water treatment residual  

Microsoft Academic Search

Conditioning of an aluminum-based water treatment sludge by single and dual polymers was investigated in this study. Capillary suction time (CST), specific resistance to filtration (SRF) and settling rate were used to evaluate the sludge dewatering characteristics. Sludge dewaterability resulting from single and dual polymer conditioning were compared for the purpose of exploring the validity and effectiveness of dual polymer

W. Ma; Y. Q. Zhao; P. Kearney

2007-01-01

427

Release of antibiotic resistant bacteria and genes in the effluent and biosolids of five wastewater utilities in Michigan  

Microsoft Academic Search

The purpose of this study was to quantify the occurrence and release of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) into the environment through the effluent and biosolids of different wastewater treatment utilities including an MBR (Membrane Biological Reactor) utility, conventional utilities (Activated Sludge, Oxidative Ditch and Rotatory Biological Contactors-RBCs) and multiple sludge treatment processes (Dewatering, Gravity Thickening,

Mariya Munir; Kelvin Wong; Irene Xagoraraki

2011-01-01

428

Limestone\\/adipic acid FGD and stack opacity reduction pilot plant tests at Big Rivers  

Microsoft Academic Search

Big Rivers Electric Corporation (BREC) contracted Peabody Process Systems, Inc. (PPSI) to install a flue gas cleaning (FGC) pilot plant at the BREC R.D. Green Station Unit No. 2 located at Sebree, KY. A six month test program was completed demonstrating technology for: alternatives to using lime as an alkali; methods for improving cake dewatering; identification of the causes of

D. Laslo; E. Bakke; E. Chisholm

1984-01-01

429

Oblique overview, looking eastsoutheast, of fish ladder construction activity after ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Oblique overview, looking east-southeast, of fish ladder construction activity after dewatering of north side. The east abutment wall, concrete crest, and north side apron are exposed. Easternmost roller gate (raised position) and service bridge at upper right - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

430

Sewage sludge incinerator fuel reduction, Hartford, Connecticut  

Microsoft Academic Search

A field demonstration project was conducted at Hartford, Connecticut, which showed that the supplemental fuel usage for sewage sludge incineration could be reduced 83%. This was accomplished by using a belt press filter for dewatering which reduced fuel usage 65% and then fuel efficient burning procedures and operator training further reduced that amount 51%. The Hartford plant originally used 122

A. J. Verdouw; E. W. Waltz; P. F. Gilbert

1984-01-01

431

SEWAGE SLUDGE INCINERATOR FUEL REDUCTION, HARTFORD, CONNECTICUT  

EPA Science Inventory

A field demonstration project was conducted at Hartford, Connecticut, which showed that the supplemental fuel usage for sewage sludge incineration could be reduced 83%. This was accomplished by using a belt press filter for dewatering which reduced fuel usage 65% and then fuel ef...

432

Pre-emptive control of moisture content in paper manufacturing using surrogate measurements  

Microsoft Academic Search

Paper manufacturing consists of the sequential removal of over 90% of the water from pulp through gravity, vacuum dewatering, pressing and thermal drying. Control of moisture content is important for paper quality and energy economy. Current strategy for the control of moisture content uses a feedback sensor at the end of the process to adjust the dryers. This introduces a

Perry Y. Li; Shri Ramaswamy; Petar Bjegovic

2003-01-01

433

PREEMPTIVE CONTROL OF MULTIPLY ACTUATED PROCESSES: APPLICATION TO MOISTURE CONTENT CONTROL IN PAPER MANUFACTURING USING SURROGATE MEASUREMENTS  

Microsoft Academic Search

Many manufacturing processes involve the successive pro- cessing of the substrate at multiple station on a transport medium, with the hope that at the end of the process, the product has the desired property. Paper manufacturing is an example in which over 90% of the water from pulp is sequentially removed through gravity, vacuum dewatering, pressing, and thermal drying. The

Perry Y. Li; Petar J. Bjegovic; Shri Ramaswamy; DSC TOC

434

Research of the flow procedures in a pressure sewer system  

Microsoft Academic Search

At the Institute of Land Reclamation, Hydrology and Sanitary Engineering of the University at Rostock the pressure and flow ratios are examined within a measuring section in the pressure dewatering system on the Darß peninsula. The objective of the research project is the knowledge upgrade about the highly unsteady hydraulic conditions in a pressure sewer system. This paper firstly presents

C. Dohse; H. Eckstädt

435

Case study: Energy savings for water reticulation system on a deep mine  

Microsoft Academic Search

In deep level mining, water reticulation systems are one of the major consumers of electricity. The refrigeration plants, together with the underground water supply and dewatering systems are integrated to form one complete water reticulation system. This integrated water reticulation system extracts hot water from the mine, cools it down and returns the cold water to the various underground mining

Jan Vosloo; Leon Liebenberg; Douglas Velleman

436

Hazardous Organic Chemicals in Biosolids Recycled as Soil Amendments  

Microsoft Academic Search

The generation and disposal of biosolids produced at municipal wastewater treatment plants is a major environmental issue. Approximately 900 kg of biosolids on a dry basis are produced from the treatment of 1 million gallons of wastewater. These solids are typically dewatered on site and disposed of at landfills, incinerators or on agricultural fields. Disposal of sewage sludge on agricultural

Alok Bhandari; Kang Xia

437

Use of alkyl sulfates in the dewaterng of a coal flotation concentrate  

SciTech Connect

The possibility has been shown of using anionic SAAs in the dewatering of a coal flotation concentrate. It has been established that the adsorption of alkyl sulfates (ASs) obeys the general laws of the adsorption of organic substances from solutions on coals. The addition of electrolytes intensifies the adsorption of ASs, leading to the hydrophobization of the coal particles. 10 refs.

Zubkova, Yu.N.; Basenkova, V.L.; Kucher, R.V.

1981-01-01

438

Plant-wide (BSM2) evaluation of reject water treatment with a SHARON-Anammox process  

Microsoft Academic Search

In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water streams on the performance of a WWTP is assessed in a simulation study, using the Benchmark

E. I. P. Volcke; K. V. Gernaey; D. Vrecko; U. Jeppsson; M. C. M. van Loosdrecht; P. A. Vanrolleghem

2006-01-01

439

Biological treatment of ammonium-rich wastewater by partial nitritation and subsequent anaerobic ammonium oxidation (anammox) in a pilot plant  

Microsoft Academic Search

In wastewater treatment plants with anaerobic sludge digestion, 15–20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant would significantly reduce the nitrogen load of the activated sludge system. Some years ago, a novel biological process was discovered in which ammonium is converted to nitrogen gas

Christian Fux; Marc Boehler; Philipp Huber; Irene Brunner; Hansruedi Siegrist

2002-01-01

440

Distribution of Demulsifiers between Crude Oil and Water phases  

Microsoft Academic Search

Using a radiosoptopic tracer to measure the concentration of demulsifiers,we studied the distribution regularity of demulsifiers between crude oil and water phases under different temperatures and found that the dewatering rate is related to the partition coefficient of demulsifier, which is quite sensitive to the variation of temperature According to the experimental results, we hold that an effective demulsifier should

NURXAT-NURAJE; WCNHAI CHEN; WEI CHEN; ZHIPING LI; HANQING WANG

1999-01-01

441

Submerged Combustion Evaporator for Concentration of Brewery Spent Grain Liquor.  

National Technical Information Service (NTIS)

A major waste stream in many breweries is the liquor resulting from spent grains dewatering prior to drying. This liquor may account for a third or more of the B.O.D.5 and suspended solids generated by a typical brewery. Initial studies of the spent grain...

J. L. Stein

1974-01-01

442

A parametric study of electrocoagulation as a recovery process of marine microalgae for biodiesel production  

Microsoft Academic Search

Microalgal biomass as feedstock for biofuel production is rapidly gaining appreciation in response to the increasing petroleum prices and the upsurge in global warming concerns. However, the process of creating concentrated biomass from microalgal cultures is limited by ineffective dewatering procedures. The economics of existing culture clarification unit operations make the process of creating biomass from microalgae unattractive for biofuel

Nyomi Uduman; Vivien Bourniquel; Michael K. Danquah; Andrew F. A. Hoadley

2011-01-01

443

Marine microalgae flocculation and focused beam reflectance measurement  

Microsoft Academic Search

The production of biodiesel from fast growing and lipid containing marine microalgal species is sustainably and economically more promising than fresh water microalgae. However, like fresh water microalgae, the process is limited by numerous factors such as the generally dilute nature of microalgal cultures, and the small size of microalgae cells, except for multi-cellular species such as Spirulina. Current dewatering

Nyomi Uduman; Ying Qi; Michael K. Danquah; Andrew F. A. Hoadley

2010-01-01

444

Appalachian clean coal technology consortium  

SciTech Connect

Novel chemicals that can be used for increasing the efficiency of fine coal dewatering was developed at Virginia Tech. During the past quarter, Reagent A was tested on three different coal samples in laboratory vacuum filtration tests. these included flotation products from Middle Fork plant, Elkview Mining Company, and CONSOL, Inc. the tests conducted with the Middle Fork coal sample (100 mesh x 0) showed that cake moisture can be reduced by more than 10% beyond what can be achieved without using dewatering aid. This improvement was achieved at 1 lb/ton of Reagent A and 0.1 inch cake thickness. At 0. 5 inches of cake thickness, this improvement was limited to 8% at the same reagent dosage. the results obtained with the Elkview coal (28 mesh x 0) showed similar advantages in using the novel dewatering aid. Depending on the reagent dosage, cake thickness, drying cycle time and temperature, it was possible to reduce the cake moisture to 12 to 14% rage. In addition to achieving lower cake moisture, the use of Reagent A substantially decreased the cake formation time, indicating that the reagent improves the kinetics of dewatering, The test results obtained with CONSOL coal were not as good as with the other coals tested in the present work, which may be attributed to possible oxidation and/or contamination.

Yoon, R.-H.; Basim, B.; Luttrell, G.H.; Phillips, D.I. [Virginia Polytechnic Inst., Blacksburg, VA (United States); Jiang, D.; Tao, D.; Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Meloy, T. [West Virginia Univ., Morgantown, WV (United States)

1997-01-28

445

Appalachian clean coal technology consortium. Technical quarterly progress report, October 1, 1996--December 31, 1996  

SciTech Connect

Novel chemicals that can be used for increasing the efficiency of fine coal dewatering was developed at Virginia Tech. During the past quarter, Reagent A was tested on three different coal samples in laboratory vacuum filtration tests. These included flotation products from Middle Fork plant, Elkview Mining Company, and CONSOL, Inc. The tests conducted with the Middle Fork coal sample (100 mesh x 0) showed that cake moisture can be reduced by more than 10% beyond what can be achieved without using dewatering aid. This improvement was achieved at 1 lb/ton of Reagent A and 0.1 inch cake thickness. At 0.5 inches of cake thickness, the improvement was limited to 8% at the same reagent dosage. The results obtained with the Elkview coal (28 mesh x 0) showed similar advantages in using the novel dewatering aid. Depending on the reagent dosage, cake thickness, drying cycle time and temperature, it was possible to reduce the cake moisture to 12 to 14% rage. In addition to achieving lower cake moisture, the use of Reagent A substantially decreased the cake formation time, indicating that the reagent improves the kinetics of dewatering. The test results obtained with CONSOL coal were not as good as with the other coals tested in the present work, which may be attributed to possible oxidation and/or contamination.

Yoon, R.H.; Basim, B.; Luttrell, G.H.; Phillips, D.I. [and others

1997-01-28

446

Appalachian Clean Coal Technology Consortium. Quarterly technical progress report, 1996  

SciTech Connect

The Appalachian Clean Coal Technology Consortium (ACCTC) has been established to help U.S. Coal producers, particularly those in the Appalachian region, increase the production of lower-sulfur coal. The cooperative research conducted as part of the consortium activities will help utilities meet the emissions standards established by the 1990 Clean Air Act Amendments, enhance the competitiveness of U.S. coals in the world market, create jobs in economically-depressed coal producing regions, and reduce U.S. dependence on foreign energy supplies. The consortium has three charter members, including Virginia Polytechnic Institute and State University, West Virginia University, and the University of Kentucky. The Consortium also includes industry affiliate members that form an Advisory Committee. In keeping with the recommendations of the Advisory Committee, first-year R&D activities were focused on two areas of research: fine coal dewatering and modeling of spirals. The industry representatives to the Consortium identified fine coal dewatering as the most needed area of technology development. Dewatering studies were conducted by Virginia Tech`s Center for Coal and Minerals Processing and a spiral model was developed by West Virginia University. For the University of Kentucky the advisory board approved a project entitled: ``A Study of Novel Approaches for Destabilization of Flotation Froth``. Project management and administration will be provided by Virginia Tech., for the first year. Progress reports for coal dewatering and destabilization of flotation froth studies are presented in this report.

Yoon, R.-H.; Phillips, D.I.; Luttrell, G.H.; Basim, B.; Sohn, S. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Jiang, X.; Tao, D.; Parekh, B.K. [Kentucky Univ., Lexington, KY (United States); Meloy, T. [West Virginia Univ., Morgantown, WV (United States)

1996-10-01

447

Nutrient and Microbial Dynamics in Biosolids Amended Soils Following Rainfall Simulation  

Microsoft Academic Search

Municipal waste treatment plants are mandated by U.S. EPA to treat domestic wastewater prior to releasing it to receiving streams. The dewatering and high temperature drying processes at the plant are considered effective in reducing microbial contaminants in the waste. The resulting solid material (biosolid) is rich in nutrients that may serve as a value-added product for plant growth. In

A. Atalay; C. Bronick; S. Pao; W. Mersie; A. Kalantari; C. Mcnamee; B. Whitehead

2007-01-01

448

THE EFFECT OF TEMPERATURE ON THE SURVIVAL OF PATHO- GENIC BACTERIA AND ASCARIS SUUM IN STORED SEWAGE SLUDGE  

Microsoft Academic Search

The reduction in pathogenic bacteria and Ascaris suum were determined during storage of sedimented, dewatered sewage sludge at 7, 13 and 21°C. The kinetics of Salmonella Typhimurium reduction differed over time as the initial decrease was temperature dependent while other factors influenced the survival in the later stages of storage. Temperature and reduction rate were highly correlated over time for

I. Berggren; A. Albihn; M. Johansson

449

30 CFR 717.17 - Protection of the hydrologic system.  

Code of Federal Regulations, 2010 CFR

...nonclogging dewatering device or a conduit spillway approved by the regulatory authority...be no out-flow through the emergency spillway during the passage of the runoff resulting...combination of principal and emergency spillways shall be provided to discharge...

2009-07-01

450

Pyrolysis of Large Coal Blocks: Implications of Heat and Mass Transport Effects for in Situ Gasification.  

National Technical Information Service (NTIS)

Dewatering of coal blocks at in-situ moisture levels was shown to markedly affect pyrolysis gas production by being the rate-limiting mechanism in heat transfer, and by causing self-gasification of the block as steam diffuses from a shrinking core of damp...

P. R. Westmoreland R. C. Forrester

1976-01-01

451

Second technical contractors' conference on peat  

SciTech Connect

This conference reported the status of the US Department of Energy Peat Program. The program includes peat resource surveys of eleven states, peat gasification process and equipment studies, dewatering studies, and environmental and socioeconomic factors in the development of peat technology. Separate abstracts were prepared for selected papers. (CKK)

Not Available

1980-01-01

452

The potential of improvements in the energy systems of sawmills when coupled dryers are used for drying of wood fuels and wood products  

Microsoft Academic Search

Sawmills produce side products that cannot be used in the pulp industry. They can, however, be used as fuel in the sawmill or elsewhere. Mass and energy flows in a sawmill are studied, using data from a Swedish sawmill. Design parameters are calculated for the dewatering and boiler capacities when a wood fuel dryer is coupled to the wood product

Roger Renström

2006-01-01

453

Solar drying in sludge management in Turkey  

Microsoft Academic Search

Two main wastewater treatment plants in Bursa city in Turkey will start to operate and produce at least 27,000 tons of dry solids per year by the end of 2006. The purpose of this study was to investigate an economical solution to the sludge management problem that Bursa city would encounter. The general trend in Turkey is mechanical dewatering to

Nezih Kamil Salihoglu; Vedat Pinarli; Guray Salihoglu

2007-01-01

454

Effects of uranium mining discharges on water quality in the Puerco River basin, Arizona and New Mexico  

Microsoft Academic Search

From 1967 until 1986, uranium mine dewatering increased dissolved gross alpha, gross beta, uranium and radium activities and dissolved selenium and molybdenum concentrations in the Puerco River as indicated by time trends, areal patterns involving distance from the mines and stream discharge. Additionally, increased dissolved uranium concen­ trations were identified in groundwater under the Puerco River from where mine discharges

PETER C. VAN METRE; JOHN R. GRAY

1992-01-01

455

HANDLING AND DISPOSAL OF SLUDGES FROM COMBINED SEWER OVERFLOW TREATMENT. PHASE III - TREATABILITY STUDIES  

EPA Science Inventory

This report documents the results of a project initiated to evaluate the handling and disposal of combined sewer overflow (CSO) treatment residuals. Bench scale thickening and pilot and full-scale centrifugation dewatering tests were performed at dry-weather and CSO treatment sit...

456

Fruit, vegetable, and grain processing wastes  

SciTech Connect

This is a literature review of fruit, vegetable and grain processing wastes. The factors affecting water usage and methods of conservation were examined. Various processes were investigated which included the pulp recovery from caustic peeled tomato skin, the dewatering of citrus, washing leafy vegetables with recycled process water and the potato processing industry.

Andrews, R.M.; Soderquist, M.R.

1980-06-01

457

Comparative hygienic characteristics of working conditions and ways of reducing hazards to health in the manufacture of ferrites by various methods  

Microsoft Academic Search

Investigations have shown that in the manufacture of ferrite powders (by the oxide mixing, salt thermal decomposition, and ceramic methods) the operations of weighing of powders, charging and discharging of mixers and grinders, grinding, knocking out of salts from metal containers after dewatering and charging of crucibles for calcining, and briquetting of oxides are accompanied by the raising in workrooms

V. A. Prilipko

1979-01-01

458

Effect of calcination temperature of kaolin as a support for zeolite membranes  

Microsoft Academic Search

Ceramic membranes specially zeolite membranes are usually used for dewatering of organics by pervaporation. In the previous work, it was observed that kaolin calcined at 1050°C has a separation factor 19.25 while kaolin calcined at 800°C does not show any separation activity and its separation factor is equal to 1. In this research, effect of calcination temperature on flux and

Toraj Mohammadi; Afshin Pak

2003-01-01

459

Effects of pretreatment in steam on the pyrolysis behavior of Loy Yang brown coal  

Microsoft Academic Search

Dewatering\\/drying of Victorian brown coal will be an integral part of future brown coal utilization processes aimed at the reduction of greenhouse gas emissions. This study aims to investigate the effects of the thermal pretreatment of brown coal in the presence of steam\\/water on its subsequent pyrolysis behavior. A Victorian (Loy Yang) brown coal was thermally pretreated in pressurized steam

Cai Zeng; George Favas; Hongwei Wu; Alan L. Chaffee; Jun-ichiro Hayashi; Chun-Zhu Li

2006-01-01

460

Automatic Thickener Control.  

National Technical Information Service (NTIS)

Direct automatic control of underflow density is found in practice to lead to a higher and more consistent degree of dewatering of a milled gold ore pulp in continuous thickening than achieved by the present method of manual operation. An ultrasonic senso...

K. J. Scott

1972-01-01

461

Acid mine groundwater in lignite overburden dumps and its prevention — the Rhineland lignite mining area (Germany)  

Microsoft Academic Search

In order to mine lignite in open pits the aquifers have to be dewatered and the overburden must be excavated and dumped. The overburden of the Rhineland mining area in Germany mostly contains pyrite, which is partly oxidized due to mining activities. The master variable of all mobilizing reactions in dumps is the content of oxidized pyrite–sulfur, which is formed

Frank Wisotzky; Peter Obermann

2001-01-01

462

Progress Report of Residue Studies on Dicamba Used for Ditchbank Weed Control.  

National Technical Information Service (NTIS)

The dimethylamine salt of dicamba was applied in the fall of 1970 to 4 dewatered laterals on the South Columbia Basin Irrigation District. The herbicide residues of dicamba and 5-hydroxy dicamba were determined in ditchbank and ditchbottom soils and in th...

H. A. Salman T. R. Bartley A. R. Hattrup

1972-01-01

463

Forward osmosis for concentration of anaerobic digester centrate  

Microsoft Academic Search

The nutrient-rich liquid stream produced during the dewatering of digested biomass (i.e., the centrate) is commonly mixed with the influent raw wastewater at wastewater treatment facilities. This increases the nitrogen and phosphorus loading on biological processes, increases operating costs, and in some cases, results in increased nutrient concentrations in the final effluent. Forward osmosis (FO) is a membrane treatment process

Ryan W. Holloway; Amy E. Childress; Keith E. Dennett; Tzahi Y. Cath

2007-01-01

464

Impact Assessment of the B.E.S.T. Thermal Sludge Drying Process in the Pulp and Paper Industry. Draft Final Report.  

National Technical Information Service (NTIS)

The Basic Extractive Sludge Treatment (B.E.S.T.) drying process is being examined as an energy-saving alternative to flash drying of partially dewatered sludge produced by wastewater treatment in the pulp and paper industry. The B.E.S.T. process relies on...

1978-01-01

465

Evaluation of Management of Water Release for Painted Rocks Reservoir, Bitterroot River, Montana, 1984 Annual Report.  

SciTech Connect

Baseline fisheries and habitat data were gathered during 1983 and 1984 to evaluate the effectiveness of supplemental water releases from Painted Rocks Reservoir in improving the fisheries resource in the Bitterroot River. Discharge relationships among main stem gaging stations varied annually and seasonally. Flow relationships in the river were dependent upon rainfall events and the timing and duration of the irrigation season. Daily discharge monitored during the summers of 1983 and 1984 was greater than median values derived at the U.S.G.S. station near Darby. Supplemental water released from Painted Rocks Reservoir totaled 14,476 acre feet in 1983 and 13,958 acre feet in 1984. Approximately 63% of a 5.66 m{sup 3}/sec test release of supplemental water conducted during April, 1984 was lost to irrigation withdrawals and natural phenomena before passing Bell Crossing. A similar loss occurred during a 5.66 m{sup 3}/sec test release conducted in August, 1984. Daily maximum temperature monitored during 1984 in the Bitterroot River averaged 11.0, 12.5, 13.9 and 13.6 C at the Darby, Hamilton, Bell and McClay stations, respectively. Chemical parameters measured in the Bitterroot River were favorable to aquatic life. Population estimates conducted in the Fall, 1983 indicated densities of I+ and older rainbow trout (Salmo gairdneri) were significantly greater in a control section than in a dewatered section (p < 0.20). Numbers of I+ and older brown trout (Salmo trutta) were not significantly different between the control and dewatered sections (p > 0.20). Population and biomass estimates for trout in the control section were 631/km and 154.4 kg/km. In the dewatered section, population and biomass estimates for trout were 253/km and 122.8 kg/km. The growth increments of back-calculated length for rainbow trout averaged 75.6 mm in the control section and 66.9mm in the dewatered section. The growth increments of back-calculated length for brown trout averaged 79.5 mm in the control section and 82.3mm in the dewatered section. Population estimates conducted in the Spring, 1984 indicated densities of mountain whitefish (Prosopium williamsoni) greater than 254 mm in total length were not significantly different between the control and dewatered sections (p > 0.20). Young of the year rainbow trout and brown trout per 10m of river edge electrofished during 1984 were more abundant in the control section than the dewatered section and were more abundant in side channel habitat than main channel habitat. Minimum flow recommendations obtained from wetted perimeter-discharge relationships averaged 8.5m{sup 3}/sec in the control section and 10.6m{sup 3}/sec in the dewatered section of the Bitterroot River. The quantity of supplemental water from Painted Rocks Reservoir needed to maintain minimum flow recommendations is discussed in the Draft Water Management Plan for the Proposed Purchase of Supplemental Water from Painted Rocks Reservoir, Bitterroot River, Montana (Lere 1984).

Lere, Mark E. (Montana Department of Fish, Wildlife and Parks, Missoula, MT)

1984-11-01

466

Identification of techniques for monitoring strains in the 72-inch diameter shaft liner for the exploratory shaft at Hanford  

SciTech Connect

A series of finite element models were used to predict the distribution of hoop and axial strains that would occur in the 72-in. ID ring stiffened shaft liner during installation. The finite element results were used to determine the optimal instrumentation locations for monitoring the behavior of the ES liner. In addition, the results provide predictive values for comparison with the actual field data during installation, grouting, and dewatering of the shaft. An additional model was prepared for simulating the time-dependent behavior of the basalt surrounding the ES shaft and the resulting loads. Because no time-dependent data for the Hanford basalt is available, the intent of the model is to provide a tool for understanding any observed strains in the ES liner that occur after grouting of the annulus and dewatering of the shaft.

Voss, C.F.; Strope, L.A.; Garnich, M.R.; Bastian, R.J.; Liebetrau, A.M. (Pacific Northwest Lab., Richland, WA (USA))

1985-01-01

467

Chitosan flocculation to aid the harvesting of the microalga Chlorella sorokiniana.  

PubMed

Microalgae are an attractive feedstock for biofuel production, however the harvesting of algal biomass from very large volumes of culture broth represents a major technological and economic challenge. One low cost strategy for addressing this challenge involves the use of flocculation as an initial dewatering step. In this study, flocculation of the green microalga Chlorella sorokiniana was explored in detail using the natural compound, chitosan as flocculant. Results show that clarification efficiency of the process can reach above 99% below pH 7. The optimal chitosan dosage (approximately 10 mg per gram algal dry weight) is determined primarily by cell concentration rather than cell age, lipid content or composition of the medium. Furthermore, the impact of flocculation on the subsequent dewatering process was determined and it was shown to reduce the volume to be processed by 20-50 folds, and significantly reduce energy input and material costs of centrifugation or filtration operations. PMID:23262003

Xu, Yanan; Purton, Saul; Baganz, Frank

2012-11-28

468

Ozonation of wastewater sludge for reduction and recycling.  

PubMed

An ozone treatment system was introduced as an alternative method for municipal sludge treatment and disposal. A pilot-scale facility was built to investigate the feasibility of the ozonation for sludge reduction and recycle. The system consists of three main parts; advanced wastewater treatment, sludge ozone treatment and belt press dewatering. Ozonation of wastewater sludge resulted in mass reduction by mineralization as well as volume reduction by improvement of dewatering characteristics. The supernatant of the ozonated sludge, consisting of solubilized organics and micro-particles, proved to be an effective carbon source for denitrification. A simple economic assessment reveals that the ozonation process can be more economical than incineration for sludge treatment and disposal at small- and medium-sized wastewater treatment plants. PMID:12479455

Ahn, K H; Park, K Y; Maeng, S K; Hwang, J H; Lee, J W; Song, K G; Choi, S

2002-01-01

469

Ethanol extraction of phytosterols from corn fiber  

DOEpatents

The present invention provides a process for extracting sterols from a high solids, thermochemically hydrolyzed corn fiber using ethanol as the extractant. The process includes obtaining a corn fiber slurry having a moisture content from about 20 weight percent to about 50 weight percent solids (high solids content), thermochemically processing the corn fiber slurry having high solids content of 20 to 50% to produce a hydrolyzed corn fiber slurry, dewatering the hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, washing the residual corn fiber, dewatering the washed, hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, and extracting the residual corn fiber with ethanol and separating at least one sterol.

Abbas, Charles (Champaign, IL); Beery, Kyle E. (Decatur, IL); Binder, Thomas P. (Decatur, IL); Rammelsberg, Anne M. (Decatur, IL)

2010-11-16

470

Leachate tests with sewage sludge contaminated by radioactive cesium.  

PubMed

The sewer systems of eastern Japan have transported radioactive fallout from the Fukushima Dai-ichi nuclear power plant accident to wastewater treatment plants, where the radioisotopes have accumulated. To better understand the potential problems associated with the disposal of contaminated sewage sludge in landfills, leachate tests were conducted with radioactive incinerator ash, cement solidification incinerator ash, and dewatered sludge cake. Radioactivity was undetectable in the eluate from incinerator ash and dewatered sludge cake, but about 30% of the radioactivity initially in cement solidification incinerator ash appeared in the eluate during the leaching experiments. Moreover, modification of test conditions revealed that the presence of Ca(2+) ions and strong alkali in the water that contacted the incinerator ash enhanced leaching of cesium. Lastly, the capacity of pit soil to absorb radioactive cesium was estimated to be at least 3.0 Bq/g (dry). PMID:23947711

Tsushima, Ikuo; Ogoshi, Masashi; Harada, Ichiro

2013-01-01

471

Nature and fate of oil sands fine tailings  

SciTech Connect

The chemical and physical properties of clay suspensions produced during oil production front oil sands are described. With a composition of approximately 70 wt% water (with some unrecovered bitumen) and 30 wt% solids (>90% less than 44 {mu}m in size), these clay suspensions consolidate very slowly. Clay aggregate or floc morphology has been shown to be a function of the water chemistry and can be manipulated to produce a tailings suspension that is easier to consolidate and dewater. Commercial oil sands processing has been going on in northeastern Alberta since 1967, and in that time approximately 250 million m of this difficult to dewater clay suspension has been produced. The reclamation options for this material (mature fine tailings) on a commercial scale are also outlined. 84 refs., 36 figs., 3 tabs.

Mikula, R.J.; Kasperski, K.L. [Western Research Centre, Devon, Alberta (Canada); Burns, R.D. [Suncor Oil Sands Group, Alberta (Canada); MacKinnon, M.D. [Syncrude Canada Ltd., Edmonton, Alberta (Canada)

1996-12-31

472

Notice of Energy RD&D Project  

SciTech Connect

The goal of the project is to develop a premium fuel from the waste materials created from the production of coal and lumber. A specific objective is to achieve a fuel having an energy value around 9,000 to 10,000 Btu/lb from the processed waste material. The fine coal obtained from coal refuse ponds will be cleaned using advanced separation technologies and then dewatered to lower moisture levels than currently realized by adding wood fibers utilizing an enhanced dewatering technique. The clean coal and sawdust will be combined and reconstituted through extrusion or briquetting to form a utility fuel that can be easily handled through the transportation process. After completion of the research tasks which includes combustion testing using the coal-wood fuel, a detailed economic evaluation of the total process will be conducted.

Rick Honaker; Geoffrey Young

2002-07-25

473

Topographic influence of longwall mining on ground-water supplies  

SciTech Connect

The extent of potential aquifer dewatering resulting from underground longwall mining is determined through application of a nonlinear finite-element model. The model represents the form of the body strain field that accompanies mining-induced subsidence, and uses strain magnitudes to define the modified hydraulic conductivity field. The model is applied to test the sensitivity of the induced strain field to ground surface topography. The location and extent of three characteristic zones of conductivity enhancement are defined, representing gravitational detachment above the panel, shear failure above the abutment, and extensile deformation at the ground surface. Correspondingly, well completion locations are ranked with their potential for dewatering representing relatively high potential in upland areas and relatively low potential in valley base locations. These results amplify and offer a phenomenological explanation of observational data. Modeling results are compared with several documented studies in the Appalachian coal fields and favorable agreement achieved.

Elsworth, D.; Liu, J. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mineral Engineering

1995-09-01

474

Role of Water Activity of Liquid in Controlling Evaporation Rate of Low-Viscosity Liquids  

Microsoft Academic Search

Viscosity of liquid is normally the most critical factor when operating an evaporator in an industrial process. This study shows that the dewatering capacity during evaporation for a low-viscosity peptone solution was reduced 40% for water activity (aw) = 0.8 and 80% for aw = 0.45. Designers of evaporators should be aware of this phenomenon if the aim is to get a high degree

Øistein Høstmark; Sigurd Teigland

2009-01-01

475

Ecological consequences of hydropower development in Central America: Impacts of small dams and water diversion on neotropical stream fish assemblages  

USGS Publications Warehouse

Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower plant (Dona Julia Hydroelectric Center) on two low-order streams (the Puerto Viejo River and Quebradon stream) draining a mountainous area of Costa Rica. Operation of the Dona Julia plant has dewatered these streams, reducing discharge to ~ 10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and downstream of diversion dams on two streams and along a ~ 4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assemblages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (< 15 in high) hindered movement of fishes. Along the ~ 4 km dewatered reach of the Puerto Viejo River, species count increased with downstream distance from the dam. However, estimated species richness and overall fish abundance were not significantly correlated with downstream distance from the dam. Our results suggested that effects of stream dewatering may be most pronounced for a subset of species with more complex reproductive requirements, classified as equilibrium-type species based on their life-history. In the absence of changes to current operations, we expect that fish assemblages in the Puerto Viejo River will be increasingly dominated by opportunistic-type, colonizing fish species. Operations of many other small hydropower plants in Costa Rica and other parts of Central America mirror those of Doha Julia; the methods and results of this study may be applicable to some of those projects.

Anderson, E.P.; Freeman, M. C.; Pringle, C.M.

2006-01-01

476

Strata-movement concepts and the hydrogeological impact of underground coal mining. [Effects of subsidence on permeability of rock above longwall  

Microsoft Academic Search

A review of mining-engineering concepts and studies in mine hydrology suggests a conceptual model linking the strata deformation, hydraulic property changes, and ground-water impacts due to underground coal mining. The pressure-arch deformation pattern about a small opening creates a local zone of increased permeabilities and dewatering in the seam and immediate roof, but should not hydraulically affect shallower aquifiers. Networks

1986-01-01

477

Partial removal of water before freezing: cultivar and pre-treatments as quality factors of frozen muskmelon ( Cucumis melo, cv reticulatus Naud.)  

Microsoft Academic Search

The influence of both the cultivar and the dehydration method, applied before freezing, on quality characteristics of dehydrofrozen muskmelon spheres has been studied. Water was removed from muskmelon cultivar Mirado and Rony, prior to freezing, by Dewatering–Impregnation–Soaking in concentrated solution (DIS) for 1 h, air dehydration and combined DIS-air dehydration to a final 50% weight reduction. The results of the

Andrea Maestrelli; Roberto Lo Scalzo; Daniela Lupi; Gianni Bertolo; Danila Torreggiani

2001-01-01

478

A modeling assessment of the thermal regime for an urban sport fishery  

Microsoft Academic Search

Water temperature is almost certainly a limiting factor in the maintenance of a self-sustaining rainbow trout (Oncorhynchus mykiss, formerlySalmo gairdneri) and brown trout (Salmo trutta) fishery in the lower reaches of the Cache la Poudre River near Fort Collins, Colorado, USA. Irrigation diversions dewater\\u000a portions of the river, but cold reservoir releases moderate water temperatures during some periods. The US

John M. Bartholow; Fort Collins

1991-01-01

479

The long-term effect of sludge application on Cu, Zn, and Mo behavior in soils and accumulation in soybean seeds  

Microsoft Academic Search

A long-term greenhouse column experiment using two soils of different textures amended with dewatered, composted and alkaline-stabilized\\u000a sludges (biosolids) tested the effect of aging on trace metal solubility, mobility and crop uptake over 15 cropping cycles.\\u000a Specifically, soil chemical properties and extractability of Cu, Zn and Mo were measured after each cropping cycle, and soybeans\\u000a (Glycine max (L.) Merr.) grown

Bojeong Kim; Murray B. McBride; Brian K. Richards; Tammo S. Steenhuis

2007-01-01

480

Industrial Applications of High Power Ultrasonics  

Microsoft Academic Search

\\u000a Since the change of the millennium, high-power ultrasound has become an alternative food processing technology applicable\\u000a to large-scale commercial applications such as emulsification, homogenization, extraction, crystallization, dewatering, low-temperature\\u000a pasteurization, degassing, defoaming, activation and inactivation of enzymes, particle size reduction, extrusion, and viscosity\\u000a alteration. This new focus can be attributed to significant improvements in equipment design and efficiency during the late

Alex Patist; Darren Bates

2011-01-01

481

Selective Recovery of Enriched Uranium from Inorganic Wastes  

Microsoft Academic Search

Uranium as U(IV) and U(VI) can be selectively recovered from liquids and sludge containing metal precipitates, inorganic salts, sand and silt fines, debris, other contaminants, and slimes, which are very difficult to de-water. Chemical processes such as fuel manufacturing and uranium mining generate enriched and natural uranium-bearing wastes. This patented Framatome ANP (FANP) uranium recovery process reduces uranium losses, significantly

Kimura

2003-01-01

482

Nitrogen removal from sludge digester liquids by nitrification\\/denitrification or partial nitritation\\/anammox: environmental and economical considerations  

Microsoft Academic Search

In wastewater treatment plants with anaerobic sludge digestion, 15-20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic nitrification\\/heterotrophic denitrification and (ii) partial nitritation\\/autotrophic anaerobic

C. Fux; H. Siegrist

2004-01-01

483

Sorption of carboxylic acid from carboxylic salt solutions at PHS close to or above the pK.sub.a of the acid, with regeneration with an aqueous solution of ammonia or low-molecular-weight alkylamine  

DOEpatents

Carboxylic acids are sorbed from aqueous feedstocks at pHs close to or above the acids' pH.sub.a into a strongly basic organic liquid phase or onto a basic solid adsorbent or moderately basic ion exchange resin. the acids are freed from the sorbent phase by treating it with aqueous alkylamine or ammonia thus forming an alkylammonium or ammonium carobxylate which dewatered and decomposed to the desired carboxylic acid and the alkylamine or ammonia.

King, C. Judson (Kensington, CA); Tung, Lisa A. (El Cerrito, CA)

1992-01-01

484

The Sanford Laboratory at Homestake: Progress and Opportunities  

NASA Astrophysics Data System (ADS)

The Homestake mine in Lead, South Dakota has been selected as the site for DUSEL. With private and State funds, re-entry activities have begun, and have achieved the de-watering and accessibility of the important 4850 level. Early science programs in geology, hydrology, and biology have been ongoing for over a year. LUX and MAJORANA, two large physics experiments, will be deployed in the Davis campus at 4850 when rehabilitation of this area is complete.

Alonso, Jose

2009-12-01

485

UTILIZATION OF POTATO-CORN BIOSOLIDS SINGLE-CELL PROTEIN AND POTATO-CORN PRIMARY WASTE BY BEEF CATTLE 1'2'3  

Microsoft Academic Search

Summary Potato-corn biosolids single-cell protein, treated with either percol or FeC13 to aid in the dewatering process, was compared with soybean meal as a source of supplemental protein for finishing beef steers. In a 100-d trial, daily gain on the FeC13-treated product (1.06 kg) indicated it was inferior to the percol-treated product (1.48 kg) or to soybean meal (1.60 kg).

J. C. Hsu; T. W. Perry; M. T. Mohler

2010-01-01

486

Sewage sludge pretreatment and disposal. (Latest citations from the NTIS Bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning techniques and equipment used in the pretreatment processes and disposal of sewage sludges. Topics include resource and energy recovery operations, land disposal, composting, ocean disposal, and incineration. Digestion, dewatering, and disinfection are among the pretreatment processes discussed. Environmental aspects, including the effects on soils, plants, and animals, are also presented. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-09-01

487

Design report small-scale fuel alcohol plant. Volume 2: Detailed construction information  

NASA Astrophysics Data System (ADS)

The objectives are to provide potential alcohol producers with a reference design and provide a complete, demonstrated design of a small scale fuel alcohol plant. The plant has the capability for feedstock preparation, cooking, saccharification, fermentation, distillation, by-product dewatering, and process steam generation. An interesting feature is an instrumentation and control system designed to allow the plant to run 24 hours per day with only four hours of operator attention.

1980-12-01

488

Uranium recovery research sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory. Quarterly progress report, January-March 1984  

SciTech Connect

Progress is reported on the following studies dealing with mill tailings: long-term stabilizaton; interim stabilization of mill tailings piles; tailings dewatering techniques; tailings neutralization and other alternatives in immobilizing toxic materials in tailings; evaluation of seepage and leachate transport from tailings disposal facilities; effluent and environmental monitoring methods and equipment and instrument testing; attenuation of radon emissions; assessment of leachate movement from uranium mill tailings; and methods of minimizing ground water contamination in in-situ leach uranium mining.

Foley, M.G.; Opitz, B.E.; Deutsch, W.J.; Peterson, S.R.; Gee, G.W.; Serne, R.J.; Hartley, J.N.; Thomas, V.W.; Kalkwarf, D.R.; Walters, W.H.; Fayer, M.J.; Wogman, N.A.; Nelson, R.W.

1984-05-01

489

Uranium recovery research sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory. Quarterly progress report, April-June 1984  

SciTech Connect

Progress is reported on the following studies dealing with mill tailings: long-term stabilization; interim stabilization of mill tailings piles; tailings dewatering techniques; tailings neutralization and other alternatives in immobilizing toxic materials in tailings; evaluation of seepage and leachate transport from tailings disposal facilities; effluent and environmental monitoring methods and equipment and instrument testing; attenuation of radon emissions; assessment of leachate movement from uranium mill tailings; and methods of minimizing ground water contamination in in-situ leach uranium mining. 1 figure.

Foley, M.G.; Deutsch, W.J.; Gee, G.W.; Hartley, J.N.; Kalkwarf, D.R.; Fayer, M.J.; Nelson, R.W.; Opitz, B.E.; Peterson, S.R.; Serne, R.J.; thomas, V.W.; Walters, W.H.; Wogman, N.A.

1984-08-01

490

A system for the treatment of sludge from land-based fish-farms  

Microsoft Academic Search

This paper describes both an experimental and a commercial-scale system for sludge dewatering and stabilisation. In the experimental system, back-wash water from rotating disk microsieves was settled in a conical sedimentation tank. This tank functioned well, commonly removing more than 75–80 % of the solids, at an overflow rate of 1.0–2.7 m·h?1. The hydraulic load was maintained low, so treatment

Asbjørn Bergheim; Simon J. Cripps; Helge Liltved

1998-01-01

491

Gas-rich sediment and coastal wetland loss in Louisiana  

Microsoft Academic Search

High rates of wetland loss in southern Louisiana provide the impetus for examining the role that trapped, biogenic gases play in regulating subsidence of coastal areas. A significant cause for wetland loss in this region is relative sea-level rise produced by sediment-volume reduction. Dewatering, grain reorientation and packing, and oxidation of organic-rich sediments are thought to be the main processes

M. D. Thompson; L. D. McGinnis; P. L. Wilkey; S. F. Miller

1993-01-01

492

Emissions of metals and organics from municipal waste-water sludge incinerators. Volume 2. Site 1 final emission-test report. Final report, 1987-90  

Microsoft Academic Search

The Site I plant treats 36MGD of wastewater and the blended primary\\/secondary sludge is dewatered to approximately 16 to 20 percent solids. Sludge is incinerated by a six-hearth unit at approximately 6.0 wet tons per hour. Emissions are controlled by a three tray impingement scrubber using either a mixture of primary and secondary effluent or just secondary effluent as the

D. R. Knisley; L. M. Lamb; A. M. Smith

1989-01-01

493

Process for changing caking coals to noncaking coals  

DOEpatents

Caking coals are treated in a slurry including alkaline earth metal hydroxides at moderate pressures and temperatures in air to form noncaking carbonaceous material. Hydroxides such as calcium hydroxide, magnesium hydroxide or barium hydroxide are contemplated for slurrying with the coal to interact with the agglomerating constituents. The slurry is subsequently dewatered and dried in air at atmospheric pressure to produce a nonagglomerating carbonaceous material that can be conveniently handled in various coal conversion and combustion processes.

Beeson, Justin L. (Woodridge, IL)

1980-01-01

494

Scrubbing gas from high-sulfur coal  

Microsoft Academic Search

A magnesium-sulfate-promoted limestone-scrubbing system designed for Associated Electric Co-op's Thomas Hill (Mo) Unit 3, removes 91% of flue-gas SOâ produced from burning 5.75%-sulfur coal. The system represents the first commerical use of promoted limestone as a reagent. A description of the processing steps is given, including sludge dewatering and recovery of soluble magnesium sulfate. Its economics is included to highlight

J. C. Yarze; H. Hurwitz

1978-01-01

495

Radionuclides in plants growing on sludge and water from uranium mine water treatment  

Microsoft Academic Search

Chemical treatment of uranium mine acid drainage generates sludge containing high radioactivity levels with, for example, 238U and 226Ra concentrations at about 18 and 9kBqkg?1 dry weight, respectively. Spontaneous vegetation, such as grass (Polygonum sp.), reeds (Phragmites australis), and bullrush (Typha latifolia) growing in sludge dewatering ponds concentrated uranium and uranium daughter radionuclides. However, bullrush growing in natural wetlands by

Fernando P. Carvalho; João M. Oliveira; Margarida Malta

2011-01-01

496

Treatment of heavy fuels for turbine power plants  

SciTech Connect

Self-cleaning separators with disc-type bowls, as designed and manufactured by Westfalia Separator AG, are in wide use for purifying and dewatering gas turbine fuels. The solids are spun out due to the high centrifugal force. The liquid mixture is separated into a heavy liquid phase (water) and a light liquid phase (oil). The separators are designed to provide optimal separating efficiency, even with constantly changing composition of the incoming product. 2 figs., 2 tabs.

Schwicking, T.S. (Westfalia Separator AG, Oelde (Germany))

1993-05-01

497

Ground Water Flow Modelling Applications in Mining Hydrogeology  

Microsoft Academic Search

Some specific features and problems of numerical modelling applications in mining environment are briefly discussed and three\\u000a modelling case studies are presented. Two of the applications are aimed at mine dewatering problems in active coal mines.\\u000a The first represents the underground hard coal mining region in the Czech part of the Upper Silesian Coal Basin. The second\\u000a example is focussed

Nada Rapantova; Arnost Grmela; David Vojtek; Josef Halir; Bedrich Michalek

2007-01-01

498

The Hybrid Finite Element Mixing Cell Method: A New Flexible Method for Modelling Mine Ground Water Problems  

Microsoft Academic Search

Dewatering operations often stop at mine closure. The ground water rebound can have undesirable consequences, which numerical\\u000a models can help one understand and manage. However, classical modelling techniques are relatively unsuitable to these contexts.\\u000a While spatially distributed and physically based models suffer difficulties due to the lack of data and the complexity of\\u000a geological and hydrogeological conditions, black-box models are

Serge Brouyère; Ph. Orban; S. Wildemeersch; J. Couturier; N. Gardin; A. Dassargues

2009-01-01

499

Overview assessment of nuclear-waste management  

NASA Astrophysics Data System (ADS)

The environmental control technologies associated with Department of Energy nuclear waste management programs were reviewed and the most urgent problems requiring further action or follow up were identified. In order of decreasing importance they are: (1) shallow land disposal technology development; (2) active uranium mill tailings piles; (3) uranium mine dewatering; (4) site decommissioning; (5) exhumation/treatment of transuranic waste at Idaho National Engineering Laboratory; (6) uranium mine spoils; and (7) medical/institutional wastes.

Burton, B. W.; Gutschick, V. P.; Perkins, B. A.; Reynolds, C. L.; Rodgers, J. C.; Steger, J. G.; Thompson, T. K.; Trocki, L. K.; Wewerka, E. M.; Wheeler, M. L.

1982-08-01

500

Modeling water and sediment contamination of Lake Pontchartrain following pump-out of Hurricane Katrina floodwater.  

PubMed

Levee failure and overtopping as a result of Hurricane Katrina caused major flooding of New Orleans, Louisiana. Floodwaters, which were contaminated with heavy metals, organic chemicals, and fecal coliform bacteria (FCB), were pumped into neighboring Lake Pontchartrain during dewatering. The impact of levee failure on water and benthic sediment concentrations in the lake was investigated by applying a numerical water quality model coupled to a three-dimensional, numerical hydrodynamic model. The model was used to compute water and benthic sediment concentrations throughout the lake for lead, arsenic, benzo(a)pyrene (BaP), and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), and water concentrations for FCB. Computed concentrations resulting from actual pumped discharges with levee failure and overtopping were compared to computed concentrations resulting from pumped discharges without levee failure or overtopping, and concentrations from both sets of conditions were compared to ecological water and sediment quality screening guideline values. The model indicated that incremental increases above pre-Katrina benthic sediment concentrations are about a factor of 10 greater with dewatering of the floodwaters than with dewatering of storm water without flooding. However, these increases for the metals are small relative to pre-Katrina concentrations. The results showed that the ecological screening-level sediment quality guideline values were exceeded for BaP and DDE in areas near the south shoreline of the lake as a result of floodwater pump-out, whereas, this was not the case for storm water removal without flooding. The model showed that lake water column concentrations should be about the same during both dewatering conditions regardless of whether there is flooding or not. PMID:17399885

Dortch, Mark S; Zakikhani, Mansour; Kim, Sung-Chan; Steevens, Jeffery A

2007-03-30