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1

Dewatering of fine coal  

SciTech Connect

The factors which control the dewatering of fine coal by gravity/centrifugal drainage and by gas displacement (vacuum/hyperbaric filtration) are evaluated. A generalized model is presented and used to describe dewatering kinetics and to establish dewatering limits. Applications to the design of dewatering systems for fine coal dewatering are discussed.

Hogg, R. [Mineral Processing Section, University Park, PA (United States)

1995-10-01

2

Dewatering nuclear waste  

SciTech Connect

This patent describes a method of dewatering a slurry containing radioactive particles to a condition for permanent storage. It comprises: removing substantially all interstitial water from the slurry; contacting the particles with a low humidity gas at a dewatering temperature. The dewatering temperature being greater than a predetermined storage temperature of about 55{degrees}F to dewater the particles by removing a volume of adsorbed water from the particles such that at the predetermined storage temperature the particles will be just unsaturated with respect to adsorbed water; and sealing the dewatered particles in a disposable container.

Temus, C.J.; Burnham, R.E.; Allan, G.R.

1990-08-28

3

Flocculation and dewatering  

SciTech Connect

This article deals with flocculation and dewatering and the developments in this field during 1989. Particular attention is paid to fine coal and a discussion of the international viewpoint on this subject is given.

Scheiner, B.J. (US Bureau of Mines (US)); Ince, D. (ECC America (US))

1990-05-01

4

Sludge dewatering technology  

SciTech Connect

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 can involve several steps, ranging from sludge flocculation and thickening to centrifugation or hydrocycling, clarification, settling and filtering. Sludge dewatering requires an understanding of three major components: the feed stock, the dewatering technology, and the ultimate reuse or disposal of the final product. The characteristics of the feed are important because each dewatering technology reacts differently depending on whether the feed stream is dilute or thick, abrasive or corrosive, fibrous or gelatinous. In addition, factors such as the quantity of feed generated, whether the process is batch or continuous, and minimum and maximum production rates are critical to the choice of dewatering technology. Knowing how the final product will be reused or disposed of helps further narrow the options.

Weismantel, G.E.

1993-04-01

5

Dewatering of fine coal  

SciTech Connect

Fine coal dewatering is one of the most pressing problem facing the coal cleaning industry. This project was undertaken with the objective of improving the dewatering process with surface chemical activation by primarily understanding the fundamental and process engineering aspects of vacuum filtration. Specific tasks for this project included -- development of an experimental apparatus and procedure to yield highly reproducible results and extensive data from each test, detailed experimental investigation of the dewatering characteristics of coal fines with and without the addition of flocculants and surfactants, and under different operating conditions, and finally identification and establishment of the physical limits of mechanical dewatering. Following are the significant conclusions from the study: Fineness and size distribution of the coal fines have the most significant influence on the coal dewatering process; usage of flocculants and surfactants is almost essential in reducing the cake moisture and in increasing the filter throughputs; based on the experimental data and the literature information, the existence of an asymptotic limit for filter cake moisture correlatable with a capillary number of the filter cake was identified. 66 refs., 23 figs., 7 tabs.

Sastry, K.V.S. (California Univ., Berkeley, CA (USA). Dept. of Materials Science and Mineral Engineering)

1991-01-01

6

NEW TECHNOLOGIES IN SLUDGE DEWATERING  

EPA Science Inventory

Three new dewatering methods are described in detail together with their performance capabilities. Using case histories of actual installations with these methods for the dewatering of primary and waste activated sludge mixtures operation, maintenance and design information is pr...

7

Dewatering blastholes cuts explosives costs  

SciTech Connect

The author discusses ways to use ANFO inexpensively. They say there are several advantages of dewatering and that there are two primary methods of dewatering blastholes or blasting areas. One method is to use pumps and poly sleeving or liners. The other method is presplit dewatering. The author lists some guidelines for presplitting for information, consideration, and discussion. Often larger mining operations require a combination of presplitting and dewatering with blasthole pumps.

Pishaw, S.R.

1987-11-01

8

Pumps to reduce dewatering costs  

SciTech Connect

Pumps for effective mine dewatering are discussed. The conditions are outlined in underground and surface dewatering (large volume, abrassive and/or corrosive particle content) which will affect the choice of pump. Self priming centrifugal pumps, submerged and multistage pumps are compared for underground and surface dewatering.

Stidger, R.W.

1983-09-01

9

Food Drying and Dewatering  

Microsoft Academic Search

Food drying and dewatering raises a growing interest because of increasing requirements in quality, specially in the production of ingredients and additives for food formulation. Heat and mass transfers, as well as mechanical phenomena and reactions kinetics induced by these transfers must be more and more carefully controlled during drying and storage.This chapter relates recent advances in- drying of solids-

Catherine Bonaui; Elisabeth Dumoulin; Anne-Lucie Raoult-Wack; Z. Berk; J. J. Bimbenet; F. Courtois; G. Trystram; J. Vasseur

1996-01-01

10

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

11

Flocculation and dewatering  

Microsoft Academic Search

The design and operation of flocculation processes are discussed in the context of the specific requirements of dewatering systems such as sedimentation and filtration. Chemical conditions, reagent selection and process operating conditions are evaluated based on the fundamental mechanisms involved in particle destabilization and floc development. Opportunities for control of floc characteristics through appropriate process design are described. Specific requirements

R. Hogg

2000-01-01

12

SLUDGE DEWATERING AND DRYING  

Microsoft Academic Search

The production of wastewater treatment sludge, the basic characteristics of the sludge and the state of the water in the sludge are described in this paper. The methods for the determination of bound water content are discussed. The literature (including patents) on sludge dewatering and drying is reviewed, including vacuum filters, belt presses, centrifuges, direct dryers, indirect dryers and combined

Guohua Chen; Po Lock Yue; Arun S. Mujumdar

2002-01-01

13

Temporary Construction Dewatering  

E-print Network

MAG910000, this letter submits a Notice of Intent (NOI) and the applicable documentation as required by the US Environmental Protection Agency (EPA) for temporary construction site dewatering under the RGP. Temporary dewatering is planned in support of the proposed site development which includes construction of a 12-story building with two to six levels of below grade parking or imaging space located in Boston, Massachusetts as shown on Figure 1 – Project Locus. The Site is bordered to the north by Fenwood Road beyond which is the BWH Shapiro Center, to the east by Vining Street, to the south by Vining Street beyond which is the Roxbury Tenants of Harvard Tower, and to the west by a parking lot beyond which is the Riverway. The Site is generally flat ranging in elevation from El. 22 to El. 26 (Boston City Base, BCB datum). A Subsurface Exploration Location Plan is included as Figure 2.

Post Office Square

2013-01-01

14

The characterisation of slurry dewatering  

Microsoft Academic Search

The dewatering of flocculated suspensions presents a significant challenge to water and waste water processing operations world-wide. Traditionally the dewatering process is enhanced through the use of flocculants or a surface chemical modifier to draw together fine particles and increase settling rates and sediment permeabilities, however, present methods of gauging chemical performance are somewhat empirical. Recently, Landman and White developed

A. A. A. Aziz; R. G. de Kretser; D. R. Dixon; P. J. Scales

15

Dewatering Peat With Activated Carbon  

NASA Technical Reports Server (NTRS)

Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.

Rohatgi, N. K.

1984-01-01

16

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...

17

Dewatering Systems for Surface Coal Mines.  

National Technical Information Service (NTIS)

This report incorporates a review of available dewatering technology and an evaluation of its relevance to surface coal mines in the interior province of the United States. Guidelines for the selection, design, and construction of dewatering systems are i...

J. E. O'Rourke, K. O'Connor

1979-01-01

18

Single-stage dewatering of FGD waste  

SciTech Connect

The Escalante Unit No. 1 flue gas desulfurization (FGD) waste slurry dewatering system represents the first domestic utility to deviate from the typical industry two-stage dewatering system design. Evaluations conducted during the design phase compared three dewatering options: 1) thickener in series with vacuum filters, 2) thickener in series with centrifuges, and 3) centrifuges with no thickener. The evaluation showed that centrifuges with no thickener (one stage) could significantly reduce capital costs. Coupled with capital costs, this option also decreases operation and maintenance costs, reduces the complexity of the system, saves a considerable amount of space, and centralized the FGD and dewatering systems within one building. This paper describes the evaluation that took place during the design phase of the project comparing the three dewatering options. Operational data for the first year of operation are presented, and operating and maintenance costs are discussed and compared with conventional two-stage dewatering systems.

Weis, J.G.; Baumgardner, D.; Hendry, D.W.

1986-07-01

19

Dewatering of fine coal using hyperbaric filter  

SciTech Connect

Removal of moisture from ultra-fine clean coal (minus 100 mesh) to below 20% level is difficult using conventional dewatering equipment. This paper describes a couple of dewatering approaches which were found to be effective in providing filter cakes containing less than 20% moisture. These approaches involve addition of metal ion-surfactant, and split size dewatering of coal without addition of any reagent.

Yang, J.; Wang, X.H.; Parekh, B.K. [Center for Applied Energy Research, Lexington, KY (United States)

1995-12-31

20

Coal filtration process and dewatering aids therefore  

SciTech Connect

This patent describes an improvement in a method for dewatering an aqueous slurry of solid coal particulates wherein the aqueous slurry contains between about 10 and 60 percent of solid coal particulates and a dewatering aid is added to the slurry followed by vacuum filtration thereof to produce a filter cake of the coal particulates. The improvement for lowering the water content of the filter cake comprises adding to the slurry prior to filtration an effective amount of a dewatering aid selected.

Keys, R.O.

1990-01-09

21

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

22

Effects of dewatering on chinook salmon redds: tolerance of four developmental phases to daily dewaterings  

SciTech Connect

Four intergravel developmental phases of chinook salmon Oncorhynchus tshawytscha were dewatered experimentally in artificial redds. The redds consisted of aquaria containing a gravel mix and supplied with 4 liters of water per minute at 10 C. Cleavage eggs and embryos (the egg phases), and eleutheroembryos and pre-emergent alevins (the alevin phases) were dewatered 20 consecutive times in 22-day tests. The egg phases were considerably more tolerant than alevins. Some cleavage eggs were killed by 12- and 16-hour daily dewaterings, but embryos survived up to 22-hour daily dewaterings. Embryos also tolerated extended, multiple dewaterings (over 60% survival for four consecutive 118-hour periods) and one-time, continuous dewatering for up to 12 consecutive days (over 80% survival). In contrast, about half the eleutheroembryos were killed by 4-hour daily dewaterings, and nearly all pre-emergent alevins were killed by 1-hour daily dewaterings. Intergravel temperatures were affected by insolation and air temperature. Intergravel temperatures increased to lethal levels during dewatering of cleavage eggs in early fall, and limited their survival. Growth of egg phases from some females was retarded by dewatering, but this phenomenon was not consistent for all egg groups. The size of surviving eleutheroembryos decreased as the length of daily dewatering periods increased.

Becker, C.D.; Neitzel, D.A.; Fickeisen, D.H.

1982-09-01

23

Dewatering cuts drilling mud and disposal costs  

Microsoft Academic Search

This paper reports on rig site dewatering of drilling fluids with recycling of processed water that can help an operator to comply with environmental rules by reducing volumes of waste and reducing long term liabilities. It can also reduce disposal costs and provide a cleaner drill site overall. Rig site dewatering is the process of injecting coagulants or flocculating chemicals

B. Pharis

1991-01-01

24

SURFACE PHENOMENA IN THE DEWATERING OF COAL  

EPA Science Inventory

The influence of certain surfactants on the dewatering of fine coal has been investigated. The surfactants investigated were found to have a two-fold effect. They were found to effect the pressure differentials required for dewatering in addition to the residual water contents of...

25

Electrokinetic dewatering of a phosphate clay  

Microsoft Academic Search

The principles of electrokinetic dewatering are: (1) electrophoresis, the movement of colloidal particles in a direct current electric field; (2) dielectrophoresis, the movement of colloidal particles in a non-uniform electric field; and (3) electro-osmosis, the water flow in porous media in a direct current electric field. Electrokinetic dewatering of a phosphate clay was investigated in an experimental program. The results

J. Q. Shang; K. Y. Lo

1997-01-01

26

Combined fields dewatering of seaweed (Nereocystis luetkeana)  

SciTech Connect

Increasing pressures on our agricultural systems necessitate the investigation of alternative food and feed sources. The ocean coasts of the world provide one potential alternative, as they provide a habitat for millions of tonnes of brown marine algae, or kelp. In this study, a combined fields (mechanical pressure and electro-osmosis) dewatering technique was investigated for dewatering kelp. Electro-osmosis was shown to significantly improve conventional press dewatering of kelp. Dewatering kelp was found to significantly reduce its ash contents and available carbohydrates, and increase its protein, fat, and uronic acid contents. Furthermore, energy costs for producing dried kelp meal were found to be significantly lower if dewatering precedes thermal drying. 35 refs., 9 figs., 3 tabs.

Lightfoot, D.G. [C.P.I. Equipment, Ltd., Parksville, British Columbia (Canada); Raghavan, G.S.V. [McGill Univ., Ste. Anne de Bellevue, Quebec (Canada)

1994-05-01

27

Salmonid redd dewatering: What do we know  

SciTech Connect

Dewatering of salmonid spawning areas causes abrupt changes in the intergravel environment that may lead to extensive losses of development phases while intergravel in redds. Information on tolerance to dewatering and the extent of physicochemical changes in the gravel during dewatering can be used to assess potential impacts and to design and implement effective mitigation methods. Studies with fall chinook salmon are summarized, and the comparisons are made with results from available literature. Potentially useful methods of mitigation are mentioned. We found that prehatch phases (cleavage eggs and embryos) can be dewatered for several successive days and survive, but posthatch phases (eleutheroembryos and alevins) usually die within 24 hours. Survival of prehatch phases during extended dewatering requires maintenance of favorable intergravel temperature and moisture levels. Elevated temperatures (up to 22/sup 0/C) can be tolerated for up to 8 hours without direct adverse effects, but freezing temperatures (/sup -/1.0/sup 0/C or below) are lethal. Dewatered gravels must remain sufficient moisture to provide near 100% humidity for egg and embryo survival. In field situations, physicochemical conditions that limit survival in dewatered gravels include residual flow, temperature, gravel size and composition, and dissolved oxygen. Biological variables such as alevin behavior and certain species characteristics also influence survival. 29 refs., 6 figs.

Becker, C D; Neitzel, D A

1983-11-01

28

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

29

Dewatering fine coal slurries by gel extraction  

SciTech Connect

A new technology called gel extraction has been evaluated to determine its economic viability in dewatering the fine and ultrafine coal slurries generated upon separation of sulfur and ash from clean coal during the physical coal cleaning process. Water must be removed from such slurries prior to transportation and combustion but the dewatering costs are substantial, especially for the fine particles below 28 mesh (0.6 mm). Gel extraction is a potential breakthrough in slurry dewatering technology. The goal of this project was to acquire the qualitative and quantitative data needed to estimate the potential of gel extraction for dewatering coal slurries. The specific objectives were to determine the maximum extents of dewatering (minimum surface moisture in the coal product), the clarity of the water removed (minimum solids content), the speed of the dewatering cycles, the service lifetime of the gels, and the factors which influence all of these. With the results obtained, an economic analysis of Ohio coal cleaning plant dewatering technologies was carried out. The polymer gel at the heart of this project, poly (N-isopropylacrylamide) (PNIPA), can swell several times its shrunken weight at 32[degrees]C by absorbing water at 25[degrees]C. In gel extraction, a shrunken NIPA gel is contacted with a slurry at ambient temperature or cooler; the gel swells by absorbing water from the slurry. The gel is then removed from the dewatered slurry and warmed above its critical temperature of 33[degrees]C, which returns it to the shrunken state by releasing the absorbed water. The facts that the gel is reusable and the process is simple and driven by low-grade energy (warm temperatures), and not inherently limited by particle size, made the process an attractive possible alternative to centrifugation, screening, filtration, etc. for slurry dewatering.

Gehrke, S.H.; Lyu, Lii-Hurng.

1990-01-01

30

Developments in coal dewatering in Australia  

SciTech Connect

The Australian coal industry is characterized by efficient fines recovery, and the climate does not dictate the use of thermal drying. With the increasing trend to underground mining and hence finer ROM coal, and market pressures for reduced product moistures, dewatering issues are assuming increasing importance in the Australian coal industry. The greatest potential gains in dewatering performance undoubtedly lie in the treatment of finely sized material. This paper examines the dewatering issues which have been recognized by the Australian coal industry, and describes current Australian research in this field.

Osborne, D.G.; Davis, J.J. [CRA-ATD, Bundoora, Victoria (Australia)

1995-10-01

31

Efficient Mechanical Dewatering by Adding Microfungi.  

National Technical Information Service (NTIS)

To achieve an effective dewatering of peat slurries one can induce aggregation of the negatively charged peat particles which restrict the waterflow through the peat matrix and the filter during pressing. When polyelectrolytes are added aggregation of the...

M. Nordstroem

1988-01-01

32

SLUDGE DEWATERING AND DRYING ON SAND BEDS  

EPA Science Inventory

Dewatering of water and wastewater treatment sludges was examined through mathematical modeling and experimental work. The various components of the research include: (1) chemical analyses of water treatment sludges, (2) drainage and drying studies of sludges, (3) a mathematical ...

33

Dewatering of contaminated river sediments  

NASA Technical Reports Server (NTRS)

Dewatering of slurries has been successfully accomplished by the proper use of polymers in flocculating the fine particulate matter suspended in mineral processing streams. The U.S. Bureau of Mines (USBM) entered into a cooperative research effort with the U.S. Army Corps of Engineers (Corps) for the purpose of testing and demonstrating the applicability of mining flocculation technology to dredging activities associated with the removal of sediments from navigable waterways. The Corps has the responsibility for maintaining the navigable waterways in the United States. Current technology relies primarily on dredging operations which excavate the material from the bottom of waterways. The Corps is testing new dredging technology which may reduce resuspension of sediments by the dredging operation. Pilot plant dredging equipment was tested by the Corps which generated larger quantities of water when compared to conventional equipment, such as the clam shell. The transportation of this 'excess' water adds to the cost of sediment removal. The process developed by the USBM consists of feed material from the barge being pumped through a 4-in line by a centrifugal pump and exiting through a 4-in PVC delivery system. A 1,000-gal fiberglass tank was used to mix the polymer concentrate. The polymer was pumped through a 1-in line using a variable speed progressive cavity pump and introduced to the 4-in feed line prior to passing through a 6-in by 2-ft static mixer. The polymer/feed slurry travels to the clarifying tank where the flocculated material settled to the bottom and allowed 'clean' water to exit the overflow. A pilot scale flocculation unit was operated on-site at the Corps' 'Confined Disposal Facility' in Buffalo, NY.

Church, Ronald H.; Smith, Carl W.; Scheiner, Bernard J.

1994-01-01

34

Some fundamental aspects of the dewatering of peat.  

National Technical Information Service (NTIS)

The purpose of this work has been to study possible dewatering systems and methods which allows a fuel peat production independent of climate and weather conditions with a special emphasise on the influence of the mechanical dewatering operation. The dry ...

M. Muenter

1991-01-01

35

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

36

Supplementary Material for: "Macroinvertebrate community responses to a dewatering  

E-print Network

Supplementary Material for: "Macroinvertebrate community responses to a dewatering disturbance for excluding the Very small dewatering effect site from the macroinvertebrate community analysis. 1 #12;Table S q q q q q q Site (Strength of dewatering effect) q q Very small Minimal Slight Moderate Severe

Doyle, Martin

37

Enhanced ultrafine coal dewatering using flocculation filtration processes  

Microsoft Academic Search

Ultrafine coal (?150 ?m) can be effectively cleaned using advanced separation techniques such as column flotation, however, dewatering it to below 20 percent moisture level using the conventional dewatering techniques is difficult. A comparative flocculation filtration study was performed for enhancing dewatering of ultrafine coal using vacuum, hyperbaric, and centrifugal filters. The cationic and anionic flocculants were added into the

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

2000-01-01

38

CHEMICAL PRIMARY SLUDGE THICKENING AND DEWATERING  

EPA Science Inventory

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 wastewater. Each chemical treat...

39

Enhanced sludge dewatering by dual polyelectrolytes conditioning  

Microsoft Academic Search

Sludge dewatering by dual polyelectrolytes conditioning was investigated in this study. Single polyelectrolyte is utilized in sludge conditioning conventionally, in which charge neutralization and bridging are involved in the reactions. In the current study, both cationic and non-ionic polyelectrolytes were utilized simultaneously in the conditioning. Waste activated sludge was sampled from a synthetic fiber plant, and used in the experiment.

C. H Lee; J. C Liu

2000-01-01

40

DEWATERING MUNICIPAL SEWAGE SLUDGES SELECTING A PROCESS  

EPA Science Inventory

Using information and data obtained for an update of the U.S. Environmental Protection Agency's guidance document on dewatering municipal wastewater sludges, a sequential review is made of key considerations in selecting an optimum process. Included in the discussion are the prin...

41

Low Cost Dewatering of Waste Slurries  

NASA Technical Reports Server (NTRS)

The U.S. Bureau of Mines has developed a technique for dewatering mineral waste slurries which utilizes polymer and a static screen. A variety of waste slurries from placer gold mines and crushed stone operations have been successfully treated using the system. Depending on the waste, a number of polymers have been used successfully with polymer costs ranging from $0.05 to $0.15 per 1,000 gal treated. The dewatering is accomplished using screens made from either ordinary window screen or wedge wire. The screens used are 8 ft wide and 8 ft long. The capacity of the screens varies from 3 to 7 gpm/sq. ft. The water produced is acceptable for recycling to the plant or for discharge to the environment. For example, a fine grain dolomite waste slurry produced from a crushed stone operation was dewatered from a nominal 2.5 pct solids to greater than 50 pct solids using $0.10 to $0.15 worth of polymer per 1,000 gal of slurry. The resulting waste water had a turbidity of less than 50 NTU and could be discharged or recycled. The paper describes field tests conducted using the polymer-screen dewatering system.

Peterson, J. B.; Sharma, S. K.; Church, R. H.; Scheiner, B. J.

1993-01-01

42

Vibration screens for dewatering of minerals -- Theory and practice  

SciTech Connect

Vibration screens are commonly used not only in classifying bulk material but also in dewatering it. The lack of a comprehensive physical theory of dewatering often leads to difficulties in the design and operation of the vibration screens. Firstly, the dewatering of bulk material will be shown, based on a physical model. Because of the oscillatory motion of the liquid in the bulk, the inertial force of the accelerated liquid and the dripping of water out of the bulk or screen must be taken into special consideration. The physical model put forward shows the effect of the various operations parameters of dewatering screens. The comparison between dewatering theory and practice will be shown by measurements using coal, limestone, etc. Dewatering measurements, which have been conducted on a vibration screen, demonstrate that different vibration frequencies and rates of acceleration lead to different residual moistures. Finally, the possibilities of improving vibration dewatering will be described.

Keller, K.; Stahl, W. [Univ. Karlsruhe (Germany). Inst. fuer Mechanische Verfahrenstechnik und Mechanik

1995-12-31

43

Application of amphoteric polyelectrolytes for sludge dewatering  

SciTech Connect

Conventional sludge conditioning with polymer flocculants usually involves the addition of either a cationic polymer or a combination of a cationic and an anionic polymer. On the other hand, a combination of a metal coagulant and an amphoteric polymer was found to produce large, mechanically strong flocs. On the basis of this observation and by use of the colloid titration method the efficiency of the sludge charge neutralization with a metal coagulant and the amount of polymer adhered to the sludge particle surfaces were measured to elucidate the mechanism of the amphoteric polymer attachment. This study indicated that amphoteric polymers were roughly divided into two main types by the cation-anion ratio of the polymer according to the efficiency of the charge neutralization. Furthermore, field survey results have demonstrated that a new system gave a two times higher dewatering rate, producing a dewatered sludge cake having a moisture content 2--5% lower than those obtained conventional methods.

Watanabe, Y.; Kubo, K.; Sato, S. [Kurita Water Industries Ltd., Atsugi, Kanagawa (Japan)] [Kurita Water Industries Ltd., Atsugi, Kanagawa (Japan)

1999-06-08

44

Space Shuttle solid rocket booster dewatering system  

NASA Technical Reports Server (NTRS)

After the launch of the Space Shuttle, the two solid rocket boosters (SRB's) are jettisoned into the ocean where they float in a spar (vertical) mode. It is cost effective to recover the SRB's. A remote controlled submersible vehicle has been developed to aid in their recovery. The vehicle is launched from a support ship, maneuvered to the SRB, then taken to depth and guided into the rocket nozzle. It then dewaters the SRB, using compressed air from the ship, and seals the nozzle. When dewatered, the SRB floats in a log (horizontal) mode and can be towed to port for reuse. The design of the remote controlled vehicle and its propulsion system is presented.

Fishel, K. R.

1982-01-01

45

SRB dewatering set. [space shuttle boosters revcovery  

NASA Technical Reports Server (NTRS)

The system components and operation of the space shuttle solid rocket booster (SRB) dewatering set are described. The SRB dewatering set consists of a nozzle plug, control console, remote control unit, power distribution unit, umbilical cable, interconnect cables, and various handling and storage items. The nozzle plug (NP) is a remotely controlled, tethered underwater vehicle that is launched from the retrieval vessel (RV) by a crane, descends down the side of the SRB, and is positioned below the SRB nozzle. A TV camera mounted at the top of the NP central core is used by the control console operator to visually guide the NP during descent and docking. The NP is then driven up and locked into the nozzle. Compressed air is passed through the umbilical from the RV, through the NP and into the SRB motor. The water inside the SRB is expelled causing the SRB to rotate to a near horizontal attitude on the surface of the water.

Wickham, R. E.

1981-01-01

46

Dewatering of activated sludge by Fenton's reagent  

Microsoft Academic Search

The specific resistance, moisture and element analysis were used to evaluate the increase in filtration and dewatering efficiency when applying the Fenton system, Fe2+\\/H2O2 and Fe3+\\/H2O2, to treat excess sludge. Addition of Fe2+, Fe3+ and H2O2 were also selected as treatment processes for comparison. The excess sludge used in this study was obtained from the wastewater treatment plant of An-Ping

Ming-Chun Lu; Chien-Jung Lin; Chih-Hsiang Liao; Rui-Yuan Huang; Wang-Ping Ting

2003-01-01

47

Electroacoustic dewatering of food and other suspensions  

SciTech Connect

The food processing industry is a large user of energy for evaporative drying due to limited effectiveness of conventional mechanical dewatering machines. Battelle's Electroacoustic Dewatering (EAD) process improves the performance of mechanical dewatering machines by superimposing electric and ultrasonic fields. A two phase development program to demonstrate the benefits of EAD was carried out in cooperation with the food processing industry, the National Food Processors Association (NFPA) and two equipment vendors. In Phase I, laboratory scale studies were carried out on a variety of food suspensions. The process was scaled up to small commercial scale in Phase II. The technical feasibility of EAD for a variety of food materials, without adversely affecting the food properties, was successfully demonstrated during this phase, which is the subject of this report. Two Process Research Units (PRUs) were designed and built through joint efforts between Battelle and two equipment vendors. A 0.5-meter wide belt press was tested on apple mash, corn fiber, and corn gluten at sites provided by two food processors. A high speed citrus juice finisher (a hybrid form of screw press and centrifuge) was tested on orange pulp. These tests were carried out jointly by Battelle, equipment vendors, NFPA, and food processors. The apple and citrus juice products were analyzed by food processors and NFPA. 26 figs., 30 tabs.

Kim, B.C.; Zelinski, M.S.; Criner, C.L.; Senapati, N.; Muralidhara, H.S.; Jirjis, B.; Beard, R.E.; Cummings, C.; Chauhan, S.P.

1989-05-31

48

Dredging and dewatering sediment containing hazardous and toxic materials  

SciTech Connect

Dredging is a common method of remediating ponds containing contaminated wastes. However, dewatering of the dredged solids is usually not well integrated with the dredging phase. As a result, overall project efficiency can be poor. Specifically, since dredges deliver material in a widely varying slurry form and since dewatering presses require the delivered material to be uniform, union of the two systems often results in inconsistent operation of the overall process. In an effort to enhance overall dredging and dewatering process production rates as well as minimize the return of suspended solids in the decant water, a new process was developed to provide a consistent dredged sludge for delivery to the press. This paper discusses modifications made to a conventional dredging and dewatering process to improve production rates and dewatering capabilities. These modifications are applicable to any project where efficient solids dewatering is required and where returning decant water must be visually free of suspended solids. 4 figs.

Askin, R.C. [Hydrometrics, Inc., Helena, MT (United States)

1996-12-31

49

Fundamental Study for Improvement of Dewatering of Fine Coal/Refuse. Semi-Annual Report, November 1981-April 1982.  

National Technical Information Service (NTIS)

The objectives of this research program are to formulate models for predicting the efficiency of mechanical dewatering, the rate of dewatering and the residual moisture content of dewatered coal/refuse and to suggest improved mechanical dewatering methods...

S. H. Chiang, G. E. Klinzing, J. W. Tierney, G. Bayles, H. Gala

1982-01-01

50

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

Code of Federal Regulations, 2013 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.815 Section 28...815 Bilge pumps, bilge piping, and dewatering systems. Instead of meeting the... (e) Each bilge suction line and dewatering system must be fitted with a...

2013-10-01

51

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

Code of Federal Regulations, 2011 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.815 Section 28...815 Bilge pumps, bilge piping, and dewatering systems. Instead of meeting the... (e) Each bilge suction line and dewatering system must be fitted with a...

2011-10-01

52

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

Code of Federal Regulations, 2010 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.815 Section 28...815 Bilge pumps, bilge piping, and dewatering systems. Instead of meeting the... (e) Each bilge suction line and dewatering system must be fitted with a...

2010-10-01

53

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

Code of Federal Regulations, 2012 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.815 Section 28...815 Bilge pumps, bilge piping, and dewatering systems. Instead of meeting the... (e) Each bilge suction line and dewatering system must be fitted with a...

2012-10-01

54

Effects of dewatering on chinook salmon redds: tolerance of four development phases to one-time dewatering  

SciTech Connect

Four intergravel development phases of chinook salmon Oncorhynchus tshawytscha were experimentally dewatered in artificial redds. The redds consisted of aquaria filled with a gravel mix and supplied with 4 liters of water per minute at 10 C. Cleavage eggs and embryos (the egg phases) and eleutheroembryos and pre-emergent alevins (the alevin phases) were each dewatered once for a continuous period. Egg phases were considerably more tolerant than alevin phases. Cleavage eggs tolerated one-time dewaterings up to 12 consecutive days (98% survival), the maximum exposure period. Embryos had similar tolerance when dewatered 12 consecutive days (92% survival), but survival declined to 64% and 53% when embryos were dewatered 16 and 20 consecutive days, respectively. Loss of embryos after the longer dewatering was associated with premature hatch. In contrast, eleutheroembryos tolerated only a 6-hour dewatering period (96% survival) and underwent high mortality when dewatered 48 consecutive hours. Pre-emergent alevins underwent near total mortality when dewatered 6 consecutive hours. Loss of alevin phases was associated with development of functional gill structures. 23 references, 3 figures.

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

1983-01-01

55

Improved FGD dewatering process cuts solid wastes  

SciTech Connect

In 2007, Duke Energy's W.H. Zimmer Station set out to advance the overall performance of its flue gas desulfurization (FGD) dewatering process. The plant implemented a variety of measures, including upgrading water-solids separation, improving polymer program effectiveness and reliability, optimizing treatment costs, reducing solid waste sent to the landfill, decreasing labor requirements, and maintaining septic-free conditions in clarifiers. The changes succeeded in greatly reducing solid waste generation and achieving total annual savings of over half a million dollars per year. 8 figs., 1 tab.

Moer, C.; Fernandez, J.; Carraro, B. [Duke Energy (United States)

2009-08-15

56

Dewatering of coal plant tailings: Flocculation followed by filtration  

Microsoft Academic Search

A sustainable alternative to tailings dam disposal of coal refuse is mechanical dewatering of tailings, which provides fast production of dry solids and water reuse. In this study, flocculation followed by filtration of coal plant tailings, a new concept in tailings dewatering is investigated in detail. This paper focuses on the effect of preconditioning tailings with varying flocculants and dosages

Naureen Alam; Orhan Ozdemir; Marc A. Hampton; Anh V. Nguyen

2011-01-01

57

Ultrafine coal single stage dewatering and briquetting process  

SciTech Connect

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 ultrafine coal particles are difficult to dewater and create problems in coal transportation, as well as in storage and handling at utility plants. The objective of this research project is to combine the ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, several types of coal samples with various particle size distributions have been tested for use in the dewatering and briquetting processes. Furthermore, various bitumen emulsions have been tested to determine the optimum dewatering reagent. These dewatering and pelletizing tests were carried out using a lab-scale ram extruder. Discharge from the dewatering and briquetting processes was tested to determine compliance with current federal and state requirements. The influence of bitumen emulsion on the sulfur content of coal pellets made were also examined. In addition, a ram extruder which can be operated continuously to simulate a rotary press operation, has been built and is currently being tested for use in the fine coal dewatering and pelletizing process.

Wilson, J.W. [Missouri Univ., Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering

1995-12-31

58

Environmental Effects of Dredging. Current District Dredged Material Dewatering Practices.  

National Technical Information Service (NTIS)

This technical note summarizes the current US Army Corps of Engineers state of practice in dewatering dredged material. State-of-practice dewatering methods are currently in full-scale use by one or more Corps of Engineers District Offices as contrasted w...

1988-01-01

59

Corps Corps River Closure Division District System Mile Structure Start Complete Length Dewatering Notes  

E-print Network

Corps Corps River Closure Division District System Mile Structure Start Complete Length Dewatering Dewater and Inspect LRD LRP Allegheny River (AMS) 62.2 Allegheny Lock 9 Apr-12 Apr-12 Y Dewater and Inspect LRD LRP Allegheny River (AMS) 52.6 Allegheny Lock 8 Apr-13 Apr-13 Y Dewater and Inspect LRD LRP

US Army Corps of Engineers

60

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

Code of Federal Regulations, 2012 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.255 Section 28...255 Bilge pumps, bilge piping, and dewatering systems. (a) Each vessel must...which water is used must be fitted with dewatering system capable of dewatering the...

2012-10-01

61

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

Code of Federal Regulations, 2011 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.255 Section 28...255 Bilge pumps, bilge piping, and dewatering systems. (a) Each vessel must...which water is used must be fitted with dewatering system capable of dewatering the...

2011-10-01

62

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

Code of Federal Regulations, 2010 CFR

...false Bilge pumps, bilge piping, and dewatering systems. 28.255 Section 28...255 Bilge pumps, bilge piping, and dewatering systems. (a) Each vessel must...which water is used must be fitted with dewatering system capable of dewatering the...

2010-10-01

63

Predicting the moisture content of coals dewatered by vacuum filters  

SciTech Connect

Coal cleaning separations, both size- and gravity-based, rely on the use of water to make the process more efficient. Removal of water from the clean coal product reduces transportation costs, handling problems, and coal utilization problems. Coal cleaning refuse is also dewatered prior to disposal. The coal industry uses a wide range of equipment to dewater coal and refuse streams in cleaning plants, including thickeners, screens, filters, centrifuges, and thermal dryers. Aspen Technology Inc. developed the Coal Cleaning Simulator (CCS) running under ASPEN PLUS{trademark}. Simulator models for coal sizing, cleaning, and dewatering devices were developed by ICF Kaiser Engineers and CQ Inc., with assistance from The Pennsylvania State University. CQ Inc. and Penn State collaborated on the dewatering models. The CCS dewatering models predict the remaining free (surface) moisture of the cake, moisture which is potentially removal by mechanical means. By definition, the free moisture is the difference between total and equilibrium moisture. The equilibrium moisture is considered non-removable. One of the simpler dewatering models in the CCS is the vacuum-disk filter model. This paper highlights the calculation for moisture content in the product from this dewatering device.

Arnold, B.J. [CQ Inc., Homer City, PA (United States)

1995-12-31

64

Dewatering fine coal slurries by gel extraction. Final report  

SciTech Connect

A new technology called gel extraction has been evaluated to determine its economic viability in dewatering the fine and ultrafine coal slurries generated upon separation of sulfur and ash from clean coal during the physical coal cleaning process. Water must be removed from such slurries prior to transportation and combustion but the dewatering costs are substantial, especially for the fine particles below 28 mesh (0.6 mm). Gel extraction is a potential breakthrough in slurry dewatering technology. The goal of this project was to acquire the qualitative and quantitative data needed to estimate the potential of gel extraction for dewatering coal slurries. The specific objectives were to determine the maximum extents of dewatering (minimum surface moisture in the coal product), the clarity of the water removed (minimum solids content), the speed of the dewatering cycles, the service lifetime of the gels, and the factors which influence all of these. With the results obtained, an economic analysis of Ohio coal cleaning plant dewatering technologies was carried out. The polymer gel at the heart of this project, poly (N-isopropylacrylamide) (PNIPA), can swell several times its shrunken weight at 32{degrees}C by absorbing water at 25{degrees}C. In gel extraction, a shrunken NIPA gel is contacted with a slurry at ambient temperature or cooler; the gel swells by absorbing water from the slurry. The gel is then removed from the dewatered slurry and warmed above its critical temperature of 33{degrees}C, which returns it to the shrunken state by releasing the absorbed water. The facts that the gel is reusable and the process is simple and driven by low-grade energy (warm temperatures), and not inherently limited by particle size, made the process an attractive possible alternative to centrifugation, screening, filtration, etc. for slurry dewatering.

Gehrke, S.H.; Lyu, Lii-Hurng

1990-12-31

65

Dewatering high-clay content preparation plant tailings  

SciTech Connect

The US Bureau of Mines is investigating a method of dewatering variety of fine-grained wastes, including coal-clay waste slurries. The method consists of mixing the waste slurry with a flocculant and dewatering the floc on static hydrosieve and/or rotary trommel screens. Laboratory tests on coal-clay waste slurries using polyethylene oxide were successful, and so small-scale continuous tests were carried out. Both series of tests are described. It was found that a static hydrosieve-type screen was sufficient to dewater the material to 50% solids. A large-scale field test unit is now being installed at a mine in Alabama.

Scheiner, B.J.

1982-09-01

66

Disposable sludge dewatering container and method  

DOEpatents

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, Clifford M. (1905 Cottonwood Dr., Aiken, SC 29803)

1993-01-01

67

Pressure, centrifugal, and electrically assisted dewatering of coal  

SciTech Connect

CSIRO and its collaborators have developed a major R and D project on dewatering of coal. This involves sub-projects on (1) the fundamentals of coal-water associations; (2) reducing the variability of product moisture levels from small coal centrifuges; (3) process mechanisms and optimization for fine coal dewatering; (4) pilot scale testing, engineering development and innovation. Results from each of these sub-projects are presented, and the pilot facility incorporating a vacuum filter, belt press, membrane press, hyperbaric filters and centrifuges, is discussed. The vacuum filter and membrane press can be configured for electric-field assisted dewatering, which provides substantial enhancements in the rate and degree of dewatering for fine coal, coal tailings, and other suspensions.

Bainbridge, N.W.; Johnston, B.K.; Lockhart, N.C. [CSIRO, North Ryde, New South Wales (Australia). Div. of Coal and Energy Technology

1995-10-01

68

Science and technology of the mechanical thermal dewatering.  

E-print Network

??In the work at hand basic experimental results are presented for the mechanical/thermal dewatering (MTE, German abbreviation for ‘Mechanisch/Thermische Entwässerung’, also used for ‘mechanical/thermal expression’… (more)

Bergins, Christian

2008-01-01

69

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

70

Moisture Distribution and Dewatering Efficiency for Wet Materials  

Microsoft Academic Search

This review paper summarizes current research efforts toward a comprehensive view of wet material dewatering, considering the binding energy as the strength to hold water, and rupture energy given to remove moisture from materials.

D. J. Lee; J. Y. Lai; Arun S. Mujumdar

2006-01-01

71

3. View southwest at dewatered culvert outlet headwall, with part ...  

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

3. View southwest at dewatered culvert outlet headwall, with part of canal bank removed in back (left) of headwall. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

72

29. VIEW NORTHWEST ON SHELTON SIDE OF DAM DURING DEWATERING. ...  

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

29. VIEW NORTHWEST ON SHELTON SIDE OF DAM DURING DEWATERING. SHELTON GATEHOUSE IN LEFT CENTER. - Ousatonic Water Power Company, Dam & Canals, CT Routes 34 & 108, 1 mile North of Derby-Shelton Bridge, Derby, New Haven County, CT

73

Guidelines for Dewatering/Densifying Confined Dredged Material.  

National Technical Information Service (NTIS)

Primary emphasis of Task 5A research was oriented toward dewatering fine-grained dredged material resulting from maintenance operations and placed in confined disposal areas. Based on results of research, as synthesized herein, it was determined that: (a)...

T. A. Haliburton

1978-01-01

74

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

75

Ultrafine coal single stage dewatering and briquetting process  

SciTech Connect

The primary goal of the current physical coal cleaning process is to reduce the ash and sulfur content from the coal, that is, to remove the mineral particles from the coal. In order to separate mineral from coal particles efficiently, the finely disseminated mineral matter must be liberated from the coal matrix with the help of an ultrafine grinding operation. The coal becomes very difficult to dewater because of the small particle size produced. Difficulty in coal transportation as well as in its storage and handling at the utility plants are also problems associated with the small coal particles resulting from ultrafine grinding. During this project, several types of coal samples with various particle size distributions have been tested for use in the dewatering and briquetting processes. Furthermore, various bitumen emulsions have been tested to determine the optimum dewatering reagent. These dewatering and pelletizing tests were carried out using a lab-scale hydraulic compacting device. Discharge from the dewatering and briquetting processes was tested to determine compliance with current federal and state requirements. The influence of bitumen emulsion on the sulfur content of coal pellets made were also examined. In addition, a ram extruder which can be operated continuously to simulate a rotary press operation, has been built and is currently being tested for use in the fine coal dewatering and pelletizing process.

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

1995-12-31

76

Campus Construction Situation Report #4 February 29th, 2012 Hechenbleikner Lake Dam --Dewatering maintenance continues. Major construction activity will  

E-print Network

Campus Construction Situation Report #4 ­ February 29th, 2012 Hechenbleikner Lake Dam -- Dewatering Report #3 ­ February 24, 2012 Hechenbleikner Lake Dam -- Dewatering maintenance continues. Major . Campus Construction Situation Report #2 ­ February 16, 2012 Hechenbleikner Lake Dam -- Dewatering

Chen, Keh-Hsun

77

Survival and behaviour of juvenile unionid mussels exposed to thermal stress and dewatering in the presence of  

E-print Network

Survival and behaviour of juvenile unionid mussels exposed to thermal stress and dewatering diminished burrowing behaviour significantly in both species (P dewatered treatment water temperature and dewatering may directly impact freshwater mussel abundance by causing mortality

Kwak, Thomas J.

78

DEVELOPMENT OF DEWATERING AIDS FOR MINERALS AND COAL FINES  

SciTech Connect

MCT has developed a suite of novel dewatering chemicals (or aids) that are designed to cause a decrease in the capillary pressures of the water trapped in a filter cake by (1) decreasing the surface tension of water, (2) increasing the contact angles of the particles to be dewatered, and (3) causing the particles to coagulate, all at the same time. The decrease in capillary pressure in turn causes an increase in the rate filtration, an increase in throughput, and a decrease in pressure drop requirement for filtration. The reagents are used frequently as blends of different chemicals in order to bring about the changes in all of the process variables noted above. The minerals and coal samples tested in the present work included copper sulfide, lead sulfide, zinc sulfide, kaolin clay, talc, and silica. The laboratory-scale test work included studies of reagent types, drying cycle times, cake thickness, slurry temperature, conditioning intensity and time, solid content, and reagent dosages. To better understand the mechanisms involved, fundamental studies were also conducted. These included the measurements of the contact angles of the particles to be dewatered (which are the measures of particle hydrophobicity) and the surface tensions of the filtrates produced from dewatering tests. The results of the laboratory-scale filtration experiments showed that the use of the novel dewatering aids can reduce the moistures of the filter cake by 30 to 50% over what can be achieved using no dewatering aids. In many cases, such high levels of moisture reductions are sufficient to obviate the needs for thermal drying, which is costly and energy intensive. Furthermore, the use of the novel dewatering aids cause a substantial increase in the kinetics of dewatering, which in turn results in increased throughput. As a result of these technological advantages, the novel dewatering aids have been licensed to Nalco, which is one of the largest mining chemicals companies of the world. At least one mineral company is currently using the technology in full-scale plant operation, which has resulted in the shutdown of a thermal dryer.

Roe-Hoam Yoon; Ramazan Asmatulu; Ismail Yildirim; William Jansen; Jinmig Zhang; Brad Atkinson; Jeff Havens

2004-07-01

79

Application of electro acoustics for dewatering pharmaceutical sludge  

SciTech Connect

Application of electro acoustic principles for dewatering has been developed by Battelle Institute. The Department of Energy, Battelle Institute, and Ashbrook-Simon-Hartley, have jointly developed an Electro Acoustic Dewatering press (EAD press). The EAD press applies a combination of mechanical pressure, electrical current and ultrasonics. This press is utilized after conventional dewatering devices and can remove up to 50% water from filtered sludge cake at a fraction of the cost incurred in existing thermal drying devices. The dominant mechanism of sludge dewatering by EAD press is electro-osmosis due to the application of a direct current field. Electro-osmosis is caused by an electrical double layer of oppositely charged ions formed at the solid liquid interface, which is characterized by zeta potential. The ultrasonic fields help electro-osmosis by consolidation of the filter cake and by release of inaccessible liquid. The EAD press has been tested successfully on a variety of materials including apple pomace, corn gluten, sewage sludge, and coal fines. A three week long full scale trial was conducted successfully at a pharmaceutical industry to determine the application of this technology for dewatering waste activated sludge.

Golla, P.S.; Johnson, H.W. (Ashbrook-Simon-Hartley, Houston, TX (United States)) Senthilnathan, P.R. (Zenon Environmental Inc., Burlington, Ontario (Canada))

1992-02-01

80

Liquidization of dewatered organic sludge and anaerobic treatment  

SciTech Connect

Dewatered sewage sludge was thermochemically liquidized at 175 {degrees}C and the liquidized sludge was separated by centrifugation to 58% (w/w) supernatant and 42% precipitate. The amount of proteins in the liquidized sludge slightly decreased through the liquidization process, however, that of lipids increased. The supernatant separated from the sludge liquidized with dewatered sewage sludge was successfully anaerobically digested. Biogas yield from the supernatant from dewatered sewage sludge at organic loading concentrations of 1.9-2.2 g VS/l during 9 days incubation was 440 ml/g-added VS and digestion ratio was 66% (w/w). Biogas yield in the case of dewatered sewage sludge was 257 ml/g-added VS and digestion ratio was 45%. Similar results were obtained in the case of the anaerobically digested with sewage sludge and dewatered sludge. Anaerobic digestion of the supernatants from the liquidized sludges resulted in high biogas productivity and high digestion ratio compared with these of the original sludges. Moreover, the precipitates contained lower moisture, therefore, they can be incinerated easier than the respective original sludges.

Sawayama, Shigeki; Inoue, Seiichi; Ogi, Tomoko [National Institute for Resources and Environment, Tsukuba, Ibaraki (Japan)

1996-12-31

81

Research and development needs in filtration and dewatering  

SciTech Connect

The first part of this paper deals with technology issues. These are categorized as (1) fundamental aspects, specifically suspension characteristics and dewatering mechanisms, along with process modelling and control; (2) pre-treatment procedures, both physical and chemical, that optimize the dewatering characteristics; (3) types of dewatering devices based on centrifuges, vacuum and pressure filters with particular reference to various combined field approaches using two or more complementary driving forces to achieve better performance. The second part of the paper (attributed principally to the first-named author) deals with related R and D issues, namely economic assessments and justification for particular R and D strategies, including benchmarking and operational factors that apply in industrial environments. Dewatering operations and R and D needs are also analyzed from the perspective of matching and integration into overall process flowsheets, and in the context of alternative processing or utilization strategies which avoid the dewatering step. The analysis concludes with a discussion on effective identification and utilization of existing knowledge, and the R and D management process. Although the paper draws heavily on experiences relating to the coal industry, much of the material is relevant to fine suspensions in general.

Lockhart, N.C. [CSIRO Div. of Coal and Energy Technology, North Ryde, New South Wales (Australia); Kern, R. [Bokela Ingenieurgesellschaft fuer Mechanische Verfahrenstechnik mbH, Karlsruhe (Germany)

1996-10-01

82

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

83

ELECTRO?DEWATERING OF SLUDGE UNDER PRESSURE AND NON?PRESSURE CONDITIONS  

Microsoft Academic Search

The electro?dewatering method is regarded as a promising approach to reduce the water content in sludge. Laboratory scale non?pressure and pressure?driven dewatering reactors were set up to study the dewatering rate in different types of sludge and the water content in the final sludge cake after electro?dewatering process. It was observed that in non?pressure experiments, the water removal rate was

V. Jurate; S. Mika

2008-01-01

84

Electrode kinetic and electro-kinetic effects in electroosmotic dewatering of clay suspensions  

SciTech Connect

Lockhart`s remarks on the author`s previous interpretation of the electrochemical aspects of the electroosmotic dewatering (EOD) of clay suspensions are analyzed to provide some further clarification. Based on Lockhart`s excellent work, the authors put forward here novel electrochemical interpretations of some features of the following experimental observations: (1) Galvani dewatering; (2) the dewatering efficiency; and (3) high voltage needed for dewatering Al-kaolinite and aluminum electrode effect.

Vijh, A.K. [Inst. de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada)

1997-05-01

85

Dewatering of coalbed methane wells with hydraulic gas pump  

SciTech Connect

The coalbed methane industry has become an important source of natural gas production. Proper dewatering of coalbed methane (CBM) wells is the key to efficient gas production from these reservoirs. This paper presents the Hydraulic Gas Pump as a new alternative dewatering system for CBM wells. The Hydraulic Gas Pump (HGP) concept offers several operational advantages for CBM wells. Gas interference does not affect its operation. It resists solids damage by eliminating the lift mechanism and reducing the number of moving parts. The HGP has a flexible production rate and is suitable for all production phases of CBM wells. It can also be designed as a wireline retrievable system. We conclude that the Hydraulic Gas Pump is a suitable dewatering system for coalbed methane wells.

Amani, M.; Juvkam-Wold, H.C. [Texas A& M Univ., College Station, TX (United States)

1995-12-31

86

A study of vacuum and pressure expression dewatering  

SciTech Connect

The relative effectiveness of vacuum filtration vs. pressure expression for dewatering of fine coal and refuse was studied using a belt filter press. For clean coal, the change in moisture content was insignificant when vacuum dewatering was followed by pressure expression for relatively large size fractions (75 ..mu..m top size). Significant reduction in moisture content was observed in case of vacuum plus expression dewatering of refuse. Addition of coarse particles (such as large Plexiglas beads and coarse coal particles) showed major reduction in cake formation time and final moisture content. Attempts to measure the actual pressure exerted by the rollers as a function of applied hydraulic pressure showed that the pressure was evenly distributed over the belt width. Porosity was observed to be significantly reduced as shearing action of the belt filter press rearranges the cake particles. Effects of belt speed, hydraulic pressure and flocculant addition on cake moisture were investigated.

Badgujar, M.N.; Chiang, S.H.

1987-01-01

87

Basin dewatering near salt domes and formation of brine plumes  

NASA Astrophysics Data System (ADS)

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 plume initially perched above a salt dome sank rapidly in the absence of an overpressured section. Where observed, perched brine plumes above salt domes must be either young, if formed by basin dewatering and vertical fluid explusion along the flanks of salt domes, or formed by a continuous mechanism. The dewatering of a thick initially overpressured sedimentary section extending from a depth of 3 km to a depth of 10 km was modeled. Conditions necessary for the formation of a perched brine plume are established.

Ranganathan, Vishnu

1992-04-01

88

Closed-loop operation with alternative dewatering technology  

SciTech Connect

The introduction of dewatering devices for closed-loop drilling-fluid circulating systems and reserve pits is derived from technology that has been used in the industrial- and sanitary-waste treatment industries for years. This paper describes an overview of the need for closed-loop systems and provides the optimum design layout, including the fit of a dewatering device, for a drilling location. The introduction of a nonconventional dewatering device, called a screw press/thickener, is reviewed. A case history describing use of this technology in a southern Louisiana inland-marsh-area well is analyzed for the technical and economic viability of operating in a closed-loop mode. Results from this effort include a viable alternative to hauling off waste fluids from drilling sites and the realization that use of this technology can be justified economically.

Halliday, W.S.; Bray, R.P.; Youens, J.W.

1993-03-01

89

REDD DEWATERING EFFECTS ON HATCHING AND LARVAL SURVIVAL OF THE ROBUST REDHORSE  

E-print Network

REDD DEWATERING EFFECTS ON HATCHING AND LARVAL SURVIVAL OF THE ROBUST REDHORSE J. M. FISK IIa , T habitats to spawn, but when power generation ceases, these areas are dewatered until the next pulse of water is released. We experimentally simulated the effects of dewatering periods on the survival

Kwak, Thomas J.

90

Analytic solution to the Martinez dewatering equations for roll gap formers  

E-print Network

Analytic solution to the Martinez dewatering equations for roll gap formers T. Boxer #3; C. T. J Dodson y W. W Sampson z March 8, 2000 Abstract A model of the roll dewatering process on a twin{wire forming. Most have been concerned with the blade forming process. Norman [1] deter- mined the dewatering

Dodson, C.T.J.

91

Dewatering Fly Ash Slurries Using Geotextile Containers M. E. Kutay1  

E-print Network

Dewatering Fly Ash Slurries Using Geotextile Containers M. E. Kutay1 , A.H. Aydilek1 and S. Hussein@eng.umd.edu Abstract The design of geotextile containers for dewatering applications typically requires good retention a single woven geotextile, significantly increases the retention capacity. Introducton Dewatering

Aydilek, Ahmet

92

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

E-print Network

ADAPTIVE PRE-EMPTIVE CONTROL OF VACUUM DEWATERING IN PAPER MANUFACTURING 1 Petar Bjegovic ¢¡ 3 by means of gravity, vacuum dewatering, mechanical pressing and thermal drying. This research proposes content, and the pressure settings in the vacuum dewatering section as actuators. The new topology has

Li, Perry Y.

93

For Table of contents use only Restructuring of colloidal cakes during dewatering  

E-print Network

1 For Table of contents use only Restructuring of colloidal cakes during dewatering J.B. Madeline1 during dewatering J.B. Madeline1 , M. Meireles1* , C. Bourgerette2 , R. Botet3 , R. Schweins4 , B. Cabane have been dewatered to the point where the colloidal aggregates connect to each other and build

94

Evaluating Technologies for Reducing Nutrients in Dairy Effluent The Geotube Dewatering System  

E-print Network

Evaluating Technologies for Reducing Nutrients in Dairy Effluent The Geotube® Dewatering System in the North Bosque and Leon River Watersheds. In 2005, they evaluated the Geotube® de-watering system The Geotube® dewatering system was demonstrated by the Miratech Division of Ten Cate Nicolon and General

Mukhtar, Saqib

95

Geotextile Tubes for the Sustainable Dewatering and Infrastructure (My Professional Journey)  

E-print Network

Geotextile Tubes for the Sustainable Dewatering and Infrastructure (My Professional Journey) Shobha K. Bhatia Syracuse University The need to dewater dredged sediments is a significant and urgent steps following the removal of sediments from water bodies is dewatering. Recently, geotextile tubes

Kamat, Vineet R.

96

A STUDY OF ACTIVATED SLUDGE DEWATERING IN EXPERIMENTAL REED-PLANTED OR UNPLANTED SLUDGE  

E-print Network

94/0169 A STUDY OF ACTIVATED SLUDGE DEWATERING IN EXPERIMENTAL REED-PLANTED OR UNPLANTED SLUDGE study; reeds; sludge dewatering; sludge drying beds; small wastewater treatment plants. INTRODUCTION). It was of interest to confirm this aptitude for dewatering sludge from extended aeration plants, a medium

Paris-Sud XI, Université de

97

Simulation of Estuarine Flooding and Dewatering with Application to Great Bay, New Hampshire  

E-print Network

Simulation of Estuarine Flooding and Dewatering with Application to Great Bay, New Hampshire Justin and dewatering of shallow estuaries is described and applications to hypothetical embayments and to the Great Bay transport implications are discussed. Keywords: Finite elements, estuarine flooding and dewatering

98

Project EARTH-13-SHELLJC1: Polygonal faults and de-watering of mudrocks during early burial  

E-print Network

Project EARTH-13-SHELLJC1: Polygonal faults and de-watering of mudrocks during early burial Shell Polygonal faults are widely regarded as a response to dewatering during the earliest stages of burial that polygonal fault genesis is related to dewatering during the first few hundred metres of burial, what is less

Henderson, Gideon

99

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

100

CO-conditioning and dewatering of chemical sludge and waste activated sludge  

Microsoft Academic Search

The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios.

G. R Chang; J. C Liu; D. J Lee

2001-01-01

101

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

102

Network model for fine coal dewatering. Part I. The model  

Microsoft Academic Search

There is a body of well established research in filtration and related subjects, but much of it has been empirical - based on correlations from experimental data. This approach has the disadvantage that it lacks generality, and it is difficult to predict the behavior of new or different systems. A more general method for studying dewatering is needed-one which will

I. Qamar; J. W. Tierney; S. H. Chiang

1985-01-01

103

A parametric study of dewatering of fine coal  

SciTech Connect

A statistical design of parametric study of pressure filtration for fine coal dewatering is presented. The effects of five major process parameters of the dewatering, i.e. applied pressure, filtration time, cake thickness, solids concentration and slurry pH, on cake moisture reduction and air consumption were investigated. The study was conducted starting with two level factorial experiments to identify the most significant parameters in the filtration process, and concluding with response surface methodologies to establish an optimum operating condition for the dewatering of fine coal with these significant variables. An operating process condition for the dewatering that provided satisfactory performance was determined to be an applied pressure of 93 psi with a cake thickness of 2.5 cm and a filtration time of 4.8 minutes for this specific laboratory filtration system. At the optimum process condition the filter cake containing about 22 percent moisture by weight was obtained and the air was consumed by 4.1 m{sup 3}/(m{sup 2} min.kg). 6 refs., 4 figs., 2 tabs.

Sung, D.J. [Yeungnam Univ., Kyongsan (Korea, Republic of); Lee, K.J. [Sangjii Univ., Wonju (Korea, Republic of); Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States)

1996-12-31

104

Mine Dewatering Studies at Jwaneng Open Pit Diamond Mine - Botswana  

Microsoft Academic Search

The geological environment at Jwaneng Mine in Botswana is characterized by a complex faulting system that preceded the emplacement of kimberlite into the Transvaal sedimentary sequence. Mine dewatering studies at Jwaneng have previously focused on identifying water bearing structures on the faulting systems that transgress the current mine pit excavations and also on the hypothesis that dolomites occurring at depths

Benjamin Mafa

105

1. VIEW LOOKING NORTH FROM DEWATERED CANAL; HEADGATES AND INTAKE ...  

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

1. VIEW LOOKING NORTH FROM DEWATERED CANAL; HEADGATES AND INTAKE CHANNEL AT LEFT; GUARDLOCK AT CENTER; SHEET PILING THROUGH SITE OF TOWPATH AT RIGHT - Dundee Canal, Headgates, Guardlock & Uppermost Section, 250 feet northeast of Randolph Avenue, opposite & in line with East Clifton Avenue, Clifton, Passaic County, NJ

106

4. View northwest at the southeast facade of the dewatered ...  

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

4. View northwest at the southeast facade of the dewatered culvert inlet headwall. Part of canal bank has been removed above the headwall. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

107

1. View southeast at northwest facade of dewatered culvert outlet ...  

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

1. View southeast at northwest facade of dewatered culvert outlet headwall, above which part of the canal bank has been removed. Buttresses and upper portion of headwall (above arches) are nineteenth-century additions to the lower, original headwall. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

108

ADEWA Artificial dewatering of peat. Interim report 1988-1990.  

National Technical Information Service (NTIS)

The overall aim of the ADEWA research program me is to develop a peat production technique based on artificial dewatering. One of the more specific research objectives is to reach, in an economically viable way, a 35 % dry matter content through mechanica...

P. Pirkonen

1991-01-01

109

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

110

PRESS DEWATERING OF BROWN COAL: PART 1EXPLORATORY STUDIES  

Microsoft Academic Search

The large water content of brown coal can be reduced by press dewatering with much lower energy requirement than by alternative methods. The cost of the press need.ed increases with the required pressing pressure, which is det e rmfned by the coal properties. The results of experiments on Victorian brown coals are interpreted with supporting theory to give these properties,

P. J. Banks; D. R Burton

1989-01-01

111

Summary Report: Pilot Plant Studies on Dewatering Primary Digested Sludge.  

National Technical Information Service (NTIS)

A 14-month pilot and plant scale sludge dewatering study was conducted at the Joint Water Pollution Control Plant (JWPCP). Discharge requirements on the effluent from this facility necessitated that at least 95% of the suspended solids be removed from the...

J. D. Parkhurst, R. F. Rodrigue, R. P. Miele, S. T. Hayashi

1973-01-01

112

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

113

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

114

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

115

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

116

Groundwater Sustainability through a Novel Dewatering Technology  

NASA Astrophysics Data System (ADS)

Groundwater plays a key role in the hydrologic cycle and ecosystem balances. Over the past decades, groundwater is intensively extracted in order to keep construction or mining sites dry. For the latter purpose the pumped water is usually discharged into a nearby surface water body or injected into an aquifer distant from the abstraction sites. As a result, aquifers are depleted and the local eco-system is disrupted as a consequence of falling groundwater tables. Given ongoing pressure on aquifer from abstraction sites, it is vital to bring up adequate attention on groundwater conservation. We demonstrate a novel technique, Düsensauginfiltration (DSI, translated as 'nozzel-suction-infiltration'), which avoids water conveyance but still lowers the groundwater table locally. The method combines abstraction of groundwater at the upper part of the aquifer with injection in the same borehole, but at a greater depth. Hence no water is withdrawn from the system. The method is already used practically in Germany, Netherlands, and China, however, it is not yet fully scientifically understood and evaluated. Currently, two tests sites in Germany, for single and multi well respectively, are selected, at which the DSI technology is currently examined. The project is cooperated with a leading dewatering company (Hoelscher Wasserbau GmbH) and funded by Deutsche Bundesstiftung Umwelt (DBU). To provide the basic principle of the method, we present numerical models solving the differential equation, which is derived from Darcy's Law and mass conservation, describing groundwater flow. We set up stationary numerical models in 2D (vertical cross section for single well case) and 3D (multi well case and/or when ambient groundwater flow is considered) using COMSOL Multiphysics. Since our model region only involves the saturated part of the unconfined aquifer, the numerical model solves a free boundary problem using hydraulic pressure as unknown variable. Two physical modes are included in the model setting. In Darcy's Law mode, we consider the changing groundwater table as free upper boundary and the impervious bottom as lower boundary. In the 2D model, the pumping and injection are specified via mass flux condition at the inner boundary, while zero hydraulic pressure is used at outer boundary for pressure constraints. Ambient groundwater flow can be considered in the 3D model using corresponding conditions at the outer model boundaries, while pumping and injection are prescribed along the borehole surfaces. A moving mesh is applied using arbitrary Lagrangian-Eulerian (ALE) method by which the location of free boundary is determined as a result. Within our simulation, the two physics modes, Darcy's Law and ALE, are coupled simultaneously. Aquifer parameters, such as hydraulic conductivity and anisotropy, are studied for sensitivity analysis. Results indicate that the method is promising especially for conductive aquifers consisting of sand and gravels. However, the short cut flow in the direct vicinity of borehole should not be ignored. For the homogenous isotropic aquifer, and equal pumping and injection rates, the DSI method yields approximately half the drawdown of the conventional approach of pumping alone. As one of the main influencing parameters, the anisotropy factor plays an important role. A decreasing anisotropy factor corresponds with deeper and wider drawdown.

Jin, Y.; Holzbecher, E.; Ebneth, S.

2012-12-01

117

Electrokinetic dewatering of Turkish glass sand plant tailings  

Microsoft Academic Search

In this study, the dewatering of glass sand plant tailings from Mersin, Turkey was investigated using an electrokinetic technique. The particle size (d80) of the solid waste material tested was less than 0.020mm and consisted mainly of silica, orthoclase, alumina, potassium and iron oxides. In current plant practice, Larox high-pressure filters are used to produce a filter cake containing 22–25%

O. Bayat; O. Kilic; B. Bayat; M. Anil; H. Akarsu; C. Poole

2006-01-01

118

Kinetics and mechanism during mechanical\\/thermal dewatering of lignite  

Microsoft Academic Search

In order to increase the efficiency of lignite fired power stations the mechanical\\/thermal dewatering (German abbreviation: MTE, Mechanisch\\/Thermische Entwässerung, also used for ‘mechanical\\/thermal expression’) was developed at the University of Dortmund as an energy efficient process for the reduction of the water content of lignite prior to combustion [1–3], [Patentschrift DE 44 34 447 A1, 1994; Patent EP 0 784

Christian Bergins

2003-01-01

119

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

2012-02-01

120

Monitoring of sludge dewatering equipment by image classification  

NASA Astrophysics Data System (ADS)

Belt filter presses represent an economical means to dewater the residual sludge generated in wastewater treatment plants. In order to assure maximal water removal, the raw sludge is mixed with a chemical conditioner prior to being fed into the belt filter press. When the conditioner is properly dosed, the sludge acquires a coarse texture, with space between flocs. This information was exploited for the development of a software sensor, where digital images are the input signal, and the output is a numeric value proportional to the dewatered sludge dry content. Three families of features were used to characterize the textures. Gabor filtering, wavelet decomposition and co-occurrence matrix computation were the techniques used. A database of images, ordered by their corresponding dry contents, was used to calibrate the model that calculates the sensor output. The images were separated in groups that correspond to single experimental sessions. With the calibrated model, all images were correctly ranked within an experiment session. The results were very similar regardless of the family of features used. The output can be fed to a control system, or, in the case of fixed experiment conditions, it can be used to directly estimate the dewatered sludge dry content.

Maquine de Souza, Sandro; Grandvalet, Yves; Denoeux, Thierry

2004-11-01

121

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

122

Environmental effects of dredging. Current district dredged material dewatering practices. Technical notes  

SciTech Connect

This technical note summarizes the current US Army Corps of Engineers state of practice in dewatering dredged material. State-of-practice dewatering methods are currently in full-scale use by one or more Corps of Engineers District Offices as contrasted with state-of-the-art methods, which may not have been demonstrated in full-scale applications. The Corps of Engineers conducted research to investigate state-of-the-art dredged material dewatering techniques under the Dredged Material Research Program (DMRP). Based on DMRP research, a number of dewatering methods have been recommended for implementation. The purpose of this note is to describe which of the dewatering practices recommended by DMRP research have been implemented and to determine whether these practices work as well in full-scale applications as was envisioned based on research studies. Also, innovative dewatering techniques developed or applied by the Districts is documented to encourage further investigation and possible use.

NONE

1988-04-01

123

ELECTROOSMOT1C DEWATERING UNDER A. C. ELECTRIC FIELD WITH PERIODIC REVERSALS OF ELECTRODE POLARITY  

Microsoft Academic Search

D.C. electric field has been usually used for electroosmotic dewatering. Under the condition of D.C., however, electrical contact resistance between the electrode and dewatering material is increased considerably with the process of dewalering. Such a circumstance hinders continuation of effective electroosmotic dewatering. To reduce the hindrance, application of A.C. electric field with periodic reversals of die electrode polarity can be

H. Yoshida; K. Kitajyo; M. Nakayama

1999-01-01

124

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

125

Application of water-soluble polymer in dewatering of fine coal  

SciTech Connect

The addition of water-soluble polymer to fine coal slurry to enhance dewatering process of fine coal is considered to be one of the most effective ways of solving the problems of dewatering of fine coal. A series of tests are conducted with a vacuum dewatering apparatus to study the effects of various factors such as the species of polymer, polymer dosage and its ways of addition, and the pH of fine coal slurry on filtrating and dewatering of fine coal.

Xingyong, W.

1999-07-01

126

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

127

The effect of coal bed dewatering and partial oxidation on biogenic methane potential  

USGS Publications Warehouse

Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

Jones, Elizabeth J. P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

2013-01-01

128

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

129

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

130

Thermochemical liquidization and anaerobic treatment of dewatered sewage sludge  

Microsoft Academic Search

Dewatered sewage sludge was thermochemically liquidized at 175°C and the liquidized sludge was separated by centrifugation to 57.7% (w\\/w) supernatant [moisture, 92.3%; volatile solid (VS), 7.0%] and 42.3% precipitate (moisture, 71.6%; VS, 18.9%). The supernatant was successfully anaerobically digested. Biogas yield from the supernatant at organic loading concentrations of 1.9–2.2 g VS\\/l during 9 days' incubation was 440 ml\\/g-added VS

Shigeki Sawayama; Seiichi Inoue; Tatsuo Yagishita; Tomoko Ogi; Shin-Ya Yokoyama

1995-01-01

131

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

132

Dewatering of coal-clay waste slurries from preparation plants. Report of investigations/1983  

SciTech Connect

The Bureau of Mines is investigating a dewatering technique for coal-clay waste that uses a flocculant, polyethylene oxide (PEO). This flocculant forms strong stable flocs that can be dewatered on a static screen. A field test unit (FTU) using this technique was operated at approximately 400 gal/min, using a waste stream from the flotation circuit of a coal preparation plant.

Brown, P.M.; Scheiner, B.J.

1983-11-01

133

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

134

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 ...

135

DEWATERING ACTIVE UNDERGROUND COAL MINES. TECHNICAL ASPECTS AND COST-EFFECTIVENESS  

EPA Science Inventory

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 exploration of hydrogeolog...

136

Advanced sludge treatment affects extracellular polymeric substances to improve activated sludge dewatering  

Microsoft Academic Search

The management of wastewater sludge, now often referred to as biosolids, accounts for a major portion of the cost of the wastewater treatment process and represents significant technical challenges. In many wastewater treatment facilities, the bottleneck of the sludge handling system is the dewatering operation. Advanced sludge treatment (AST) processes have been developed in order to improve sludge dewatering and

Elisabeth Neyens; Jan Baeyens; Raf Dewil; Bart De heyder

2004-01-01

137

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

1992-06-01

138

Effect of acid and surfactant treatment on activated sludge dewatering and settling  

Microsoft Academic Search

The effect of pretreating activated sludge with sulfuric acid and surfactant on its exocellular polymer(ECP), dewaterability and settleability was investigated. It was observed that the centrifugal dewatering efficiency was increased with the decrease of sludge pH value, and which was further improved if the surfactant was simultaneously applied. However, to the filtration dewatering, the water content reached the minimum in

Yinguang Chen; Haizhen Yang; Guowei Gu

2001-01-01

139

Effect of osmotic dewatering on rheological properties of apple subjected to convective drying  

Microsoft Academic Search

Apple v. Idared cut in cubes was dewatered by osmosis and subsequently dried by convection. Dewatering caused substantial changes in mechanical properties of apple tissue. Shrinkage due to osmotic pre-treatment was small but stiffness was half the value obtained by convective drying of apple cubes to the same final water content. In a viscous-elastic model of apple tissue, osmotic treatment

Piotr P Lewicki; Anna Lukaszuk

2000-01-01

140

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

141

EVALUATION OF SOLIDS DEWATERING FOR A PILOT-SCALE THIOSORBIC LIME SO2 SCRUBBER  

EPA Science Inventory

The paper gives results of an evaluation of solids dewatering for a pilot-scale thiosorbic lime SO2 scrubber. Pilot plant data showed that the dissolved magnesium in thiosorbic lime caused deterioration of solids dewatering properties. The slurry settling rate increased when the ...

142

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

143

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...

144

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

145

GEOCHEMISTRY, GEOPHYSICS, GEOSYSTEMS, VOL. ???, XXXX, DOI:10.1029/, Dewatering textures in the world's largest exposed1  

E-print Network

GEOCHEMISTRY, GEOPHYSICS, GEOSYSTEMS, VOL. ???, XXXX, DOI:10.1029/, Dewatering textures processes of sand slurry8 flow, multiple pore fluids, and dewatering after emplacement. The injection9-sand slurry intruded16 the dewatering sands and locally deformed the laminae. Compaction of the17 injectite

Long, Bernard

146

Impacts of fishing by dewatering on fish assemblages of tropical floodplain wetlands: A matter of frequency and context  

E-print Network

Impacts of fishing by dewatering on fish assemblages of tropical floodplain wetlands: A matter 2010 Accepted 2 November 2010 Available online 8 December 2010 Keywords: Dewatering Floodplain wetlands may be dewatered for the dual purpose of crop irrigation and fish harvesting. Viewed as highly

Lorenzen, Kai

147

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 {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. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

Groppo, J.G.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Rawls, P. [Department of Energy, Pittsburgh, PA (United States)

1995-11-01

148

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

149

Investigation of operating variables in the fine coal dewatering and briquetting process  

SciTech Connect

Illinois basin coals contain minerals, including pyrite, which are finely disseminated in micron-size particles. To liberate these mineral matters from the coal matrix, an ultra-fine grinding operation is required, followed by a wet physical cleaning process, such as column flotation. However, the resulting product possesses large surface areas that conventional dewatering techniques cannot perform effectively, and this creates transportation, storage and handling problems at utility plants. To take full advantage of these cleaning technologies, a new dewatering and coal consolidation method must be developed at the downstream end of the deep coal-cleaning process. Following an initial study at the University of Missouri-Rolla (UMR), briquetting was chosen to perform the dual purpose of dewatering and consolidating the fine coal. A bitumen-based emulsion, Orimulsion, proved to be an effective binder and dewatering agent in the briquetting process that assisted in the expulsion of water from the fine coal.

Kan, S.W.; Wilson, J.W.; Dharman, T. [Univ. of Missouri, Rolla, MO (United States)

1998-04-01

150

Simultaneous dewatering and reconstitution in a high-gravity solid-bowl centrifuge  

SciTech Connect

The Pittsburgh Energy Technology Center has developed a dewatering and reconstitution process in which bitumen emulsion is added to a fine clean coal slurry ahead of the dewatering device. The process simultaneously improves dewatering efficiency and reduces dustiness of the fine coal product during subsequent handling. This paper describes the test results from dewatering and reconstitution of fine coal in a 500 lb. per hour continuous bench scale high-gravity solid-bowl centrifuge in PETC`s Coal Preparation Process Research Facility. Test results will be evaluated in terms of type and dosage of emulsion, product moisture and strength, and product handling and dust reduction efficiency. A preliminary cost analysis will also be included.

Wen, W.W.; Gray, M.L.; Killmeyer, R.P.; Finseth, D.H. [USDOE Pittsburgh Energy Technology Center, PA (United States)

1994-12-31

151

To enhance the dewatering of vacuum filter by adding surfactant reagent  

SciTech Connect

A vacuum filter is the main equipment for fine coal dewatering and usually the moisture content of the cake is high. It has a number of serious handling problems. To reduce the moisture content of the cake, surfactant is added to the slurry which is fed to the filter system to enhance dewatering efficiency. Different kinds of surfactant have been used in the laboratory filter system. A variety of tests have been done and the factors which influence dewatering are investigated. Four of the surfactants have good dewatering efficiency. The moisture contents are decreased 5% or so. Two of them have been used in a commercial process. The method is very simple and will solve an excess moisture problem of coal preparation plants.

Cai, Z.; Wu, J.; Liu, H.; Xu, S. [China Univ. of Mining and Technology (China). Dept. of Coal Preparation and Utilization

1997-12-31

152

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

153

Evaluation of reed bed technology to dewater Army wastewater treatment plant sludge. Final report  

Microsoft Academic Search

As operator of over 100 small wastewater treatment plants (WWTPs), the Army has an interest in efficient and cost-effective sludge dewatering systems. Many Army wastewater treatment plants use conventional sand-drying beds to dewater sludge. However, sand drying involves costly regular removal of sludge, and sand-drying beds are vulnerable to operational problems with long drying periods during wet weather and sand

B. J. Kim; R. R. Cardenas; S. P. Chennupati

1993-01-01

154

Sludge dewatering by sand-drying bed coupled with electrodewatering at various potentials  

Microsoft Academic Search

Large amounts of water in sludge from wastewater treatment plants directly translate into high transport and handling costs. In this study, a laboratory scale sludge sand-drying bed was coupled with an electro-dewatering process to investigate the trends of dewatering at variable voltage potentials. There was a two-fold increase of dry solid (DS) content in final sludge cake when the applied

A. T. Pham; M. Sillanpää; J. Virkutyte

2010-01-01

155

The study and practice of clean coal pressure filter and dewatering process  

SciTech Connect

This paper introduces the current status of dewatering of the flotation clean coal and the problems in China. The industrial application of the dewatering process and the newly developed clean coal pressure filter is represented. And the results indicated that this filter press possesses such advantages as fast speed in filter lower moisture in filter cake, convenience in operation, obvious saving on energy, etc. It will have a broad applications.

Xie, G.; Wu, L.; Ou, Z.

1999-07-01

156

Combined method for simultaneously dewatering and reconstituting finely divided carbonaceous material  

SciTech Connect

A finely-divided carbonaceous material is dewatered and reconstituted in a combined process by adding a binding agent directly into slurry of finely divided material and dewatering the material to form a cake or consolidated piece which can be hardened by drying at ambient or elevated temperatures. Alternatively, the binder often in the form of a crusting agent is sprayed onto the surface of a moist cake prior to curing.

Wen, Wu-Wey (Murrysville, PA); Deurbrouck, Albert W. (Pittsburgh, PA)

1990-01-01

157

Ultrafine coal single stage dewatering and briquetting process. Technical report, September 1--November 30, 1994  

SciTech Connect

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 ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out in conjunction with a selected hydrophobic binder as the dewatering reagent and an uniaxial hydraulic press. The influence of compaction pressure and binder concentration (2 to 5%) on the performance of coal pellets have been evaluated in terms of their water and wear resistance. A laboratory scale ultrafine coal dewatering and briquetting extruder that can be operated continuously for coal pellets fabrication, has been designed and built, and will be available for testing in the next quarter.

Wilson, J.W. [Univ. of Missouri, Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering

1994-12-31

158

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

SciTech Connect

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 ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out using Orimulsion as the dewatering reagent. A ram extruder that can be operated continuously is used to fabricate dewatered pellets. The influence of compaction pressure, curing time, binder concentration (2% to 5%), particle size, and compacting time on the performance of coal pellets have been evaluated in terms of their water resistance and wear vulnerability.

Wilson, J.W.

1996-03-01

159

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal: Third quarterly progress report, (April--June 1989)  

SciTech Connect

Battelle, in cooperation with the Electric Power Research Institute (EPRI), Ashbrook-Simon-Hartley (ASH), Kaiser Engineers (KE), Lewis Corporation, and Professor S.H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine and ultrafine coals. The advanced process, called Electroacoustic Dewatering (EAD), capitalizes on the adaptation of synergistic effects of electric and acoustic fields to commercial coal dewatering systems, such as belt filter presses. 2 figs., 2 tabs.

Not Available

1989-07-18

160

Fundamental study for improvement of dewatering of fine coal/refuse. Semi-annual report, November 1981-April 1982  

SciTech Connect

The objectives of this research program are to formulate models for predicting the efficiency of mechanical dewatering, the rate of dewatering and the residual moisture content of dewatered coal/refuse and to suggest improved mechanical dewatering methods. To achieve these objectives, the following tasks are being carried out: (1) characterization of fine coal particles and filter cakes; (2) theoretical models for fine coal dewatering, (3) experimental measurement of dewatering; and (4) enhanced dewatering methods. Some highlights for this reporting period are: (1) important improvements in the micrographic analysis of coal filter cakes were achieved, (2) refinement of the model to predict the one-phase flow rate and permeability for the coal cake was initiated; (3) controlled filtration and dewatering experiments were carried out with different size fractions of the -32 mesh Pittsburgh seam-Bruceton mine coal; (4) filtration and dewatering experiments with five surfactants were completed; and (5) data analysis shows a strong correlation for the adsorption isotherm of all five surfactants with the reduction in moisture content. 6 references, 31 figures, 7 tables.

Chiang, S.H.; Klinzing, G.E.; Tierney, J.W.; Bayles, G.; Gala, H.; Kakwani, R.; Pien, H.L.; Rega, R.; Yetis, U.

1982-05-01

161

Pyrolysis characteristics and kinetic analysis of different dewatered sludge.  

PubMed

Pyrolysis behavior and kinetic properties of four different sludge, including raw sludge and three sludge respectively dewatered with FeCl3/CaO, FeCl3/CaO/coal and Fenton's reagent (Fe(2+)+H2O2)/CaO, were analyzed by using thermogravimetry coupled with Fourier transform infrared spectrometry (TG-FTIR). The results show that organics of raw sludge mainly decomposed at 378-676K, and the decomposition temperature of conditioned sludge was prolonged to 823K. Addition of coal and catalysis of CaO/ferric salt both promoted sludge pyrolysis, leading to more NH3, CH4 and CO productions. Compared with dry sludge, wet sludge pyrolysis was hard to finish completely, and the first peak of organics' decomposition appeared at higher temperature (about 573K). Additionally, the global reaction model was suited to determine kinetic parameters, which showed that dry sludge conditioned with more CaO addition had higher E values than those of dry raw sludge. Opposite results were obtained when sludge samples were wet. PMID:25151077

Zhang, Qiang; Liu, Huan; Liu, Peng; Hu, Hongyun; Yao, Hong

2014-10-01

162

Growth of microalgal biomass on supernatant from biosolid dewatering.  

PubMed

The paper reports the results of an experiment to assess the feasibility of including a photobioreactor within the design of a wastewater treatment plant, growing microalgae on the centrate from anaerobic sludge dewatering. The growth of algal biomass would take advantage of the available nitrogen and provide a substrate for biogas production by anaerobic digestion. Tests were carried out by semi-continuously feeding a photobioreactor with a centrate-effluent blend and by increasing the fraction of centrate. The experimental results show that the centrate does not induce any toxicity and, on the contrary, can be well utilized by microalgae, whose average specific growth rate (?), on centrate as such, was between 0.04 and 0.06 d(-1). The maximum biomass concentration in the photobioreactor effluent was 1.6 gSS/L at 10 days HRT (hydraulic retention time). Methane production tests led to biochemical methane production values of 335 ± 39, and 284 ± 68 mL 0°C, 1 atm CH4/g VS for the two tested samples, in agreement with literature values. Settling tests show that the settling capacity of microalgae, although satisfactory, could be effectively improved after mixing with activated sludge, confirming the potential to use the existing primary settler for microalgae thickening in order to feed microalgae for anaerobic digestion with primary/secondary sludge. PMID:24569293

Ficara, E; Uslenghi, A; Basilico, D; Mezzanotte, V

2014-01-01

163

Can sludge dewatering reactivate microorganisms in mesophilically digested anaerobic sludge? Case of belt filter versus centrifuge.  

PubMed

The anaerobic digestion process that successfully reduces the organic content of sludge is one of the most common alternatives to meet pathogen reduction requirements for particular classes of biosolids. However, recently it was reported that, much higher densities of indicator bacteria were measured in dewatered cake samples compared to samples collected after anaerobic digestion. Additionally, this increase was commonly observed after centrifugation but not after belt filter dewatering. Several hypotheses were tested to explain this occurrence; however, much of the attention was given to the reactivation of the indicator bacteria which might enter a viable but non-culturable state (VBNC) during digestion. The objective of this research is to examine sludge samples from 5 different full-scale treatment plants in order to observe the effect of dewatering processes on the reactivation potential of indicator bacteria. The bacterial enumerations were performed by both Standard Culturing Methods (SCM) and quantitative polymerase chain (qPCR) on samples collected after digestion and dewatering. Results obtained by SCM indicated that in two investigated treatment plants operating belt filter dewatering, an average 0.6 log decrease was observed after the dewatering process. However, 0.7-1.4 log increases were observed immediately after centrifuge dewatering for the other three treatment plants. On the other hand, qPCR results gave 0.1-1.9 log higher numbers compared to SCM. Comparative evaluation of results obtained by two analytical methods for five treatment plants indicates that the differences observed might be originating from both reactivation of VBNC bacteria and amplification of DNA from dead cells found in the sludge. PMID:23141737

Erkan, M; Sanin, F D

2013-01-01

164

Experience dewatering fine coal in solidbowl centrifuges at the York Canyon preparation plant  

SciTech Connect

In 1990, a study was undertaken at P&M`s York Canyon preparation plant to evaluate options for dewatering froth flotation product. The existing vacuum disc filter was in need of replacement from wear and neglect, and analysis of the feed to the filter showed that only 7% of the particles were larger than 0.15mm (100 mesh) while nearly 60% of the particles were finer than 0.45mm (325 mesh). Size analysis of the filter cake indicated a mass mean diameter (MMD) of 0.092mm and surface moisture of the filter cake was 33%. Preliminary modeling indicated that a surface moisture of 26% might be attainable for this cake with efficient mechanical dewatering. Based upon the fineness of the feed and the need to replace the filter, in 1991 P&M conducted the field testing with a pilot-scale Sharples high-G solidbowl centrifuge. Data from the pilot scale tests led to the conclusion that the solidbowl centrifuges could recover over 90% of feed solids while providing a surface moisture of about 25% in the product cake. When a decision was made in 1992 to replace the existing plant at York Canyon with a new, larger preparation plant, the commercial scale Sharples high-G solidbowl centrifuges were selected for fine dewatering. The following discussion deals with the plant fine coal dewatering circuitry, start-up problems, remedial actions, and machine dewatering performance.

Alderman, J.K. [Pittsburg & Midway Coal Mining Co., Englewood, CO (United States)

1995-08-01

165

Study of a solvent/binder combination for viscosity reduction of Orimulsion in fine coal dewatering  

SciTech Connect

To effectively liberate finely disseminated minerals from a coal matrix, a pulverization operation is needed. In this process fine coal particles are formed that possess large surface areas that are difficult to dewater, and create transportation, storage and handling problems at coal cleaning and utility plants. Using both laboratory and pilot scale models, research work conducted at the Department of Mining Engineering at University of Missouri - Rolla (UMR) on a single-stage fine coal dewatering and briquetting technique, has shown the potential of briquetting to enhance the handling, transportation, and storage of fine coal. The operation uses a hydrophobic binder as the dewatering and briquetting agent and requires a compaction device, specifically, a commercial-scale briquetting machine. In the single-stage dewatering/briquetting process, a bitumen-in-water emulsion (Orimulsion), which has high viscosity even at room temperature, was selected as the binder. Due to the tacky nature of the binder, it was felt that by reducing its viscosity using a solvent, the binder could more effectively coat the fine coal surfaces. This study investigated the efficiency of a solvent/binder combination for reducing the viscosity of the Orimulsion for the dewatering of fine coal, and making robust briquettes from predominantly -400 mesh coal particles.

Kan, S.W.; Wilson, J.W.; Dharman, T.; Aksoy, B.S. [Univ. of Missouri, Rolla, MO (United States)

1998-04-01

166

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

167

Impact of environmental dewatering of Lower Granite and Little Goose reservoirs on benthic invertebrates and macrophytes  

SciTech Connect

An investigation into the effects of dewatering on the benthic fauna in Lower Granite and Little Goose reservoirs was undertaken. Benthos in both the soft bottom regions of the reservoirs as well as those inhabiting the rock rip-rap along the shoreline were studied. These organisms provide an important food resource for both migrating salmonids and resident fish species; thus, impacts of contemplated dewatering schemes require evaluation. The results of these studies indicate that there were no significant, long-term impacts to the soft bottom benthos as a result of dewatering in Little Goose Reservoir. In fact, higher numbers of some taxa indicate that there may have been a washout of these organisms from Lower Granite Reservoir with subsequent deposition in the upper reaches of Little Goose Reservoir. This should be accompanied by a coincident decrease in these organisms in Lower Granite Reservoir. However, we did not have pre-dewatering samples from Lower Granite Reservoir with which we could compare post-filling samples to determine if the dewatering resulted in lower benthic populations.

Cushing, C.E.

1993-09-01

168

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

169

Plant selection for dewatering and reclamation of tailings  

SciTech Connect

A two-phase greenhouse experiment was conducted to identify the most suitable species for dewatering and reclamation of Composite Tailings (CT) from Alberta oil sands operated by Syncrude Canada Ltd. and Copper Mine Tailings (CMT) from the Kennecott site in Utah. A total of 15 and 9 plant species were selected for testing in CT and CMT, respectively. In Phase 1, distilled water was added weekly to simulate local precipitation. The initial solids content were 80% and 76% and the electrical conductivities were 1.1 dS/m and 3.2 dS/m for CT and CMT, respectively. All plants survived after a ten-week period. In Phase 2 only process water was added weekly to provide a worst case scenario of no precipitation and water recharge due only to process water being released from within the tailings. The initial solids contents were 65% and 76% for CT and CMT, respectively. Surface (0--3 in.) salinity increased dramatically due to the application of process water only; at the end of Phase 2 it had reached toxic levels of approximately 18.9 dS/m and 35.0 dS/m in CT and CMT, respectively. Many plants showed signs of stress due to the high salinity level. The plants which performed the best under both phases in Composite Tailings were creeping foxtail (Alopecurus arundinaceus), reed canarygrass (Phalaris arundinacea), Altai wildrye (Elymus angustus), and red top (Agrostis stolonifera); and in Copper Mine Tailings were Altai wildrye, smooth bromegrass (Bromus inermis) and creeping foxtail.

Silva, M.J.; Naeth, M.A.; Biggar, K.W.; Chanasyk, D.S.; Sego, D.C. [Univ of Alberta, Edmonton (Canada)

1998-12-31

170

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

171

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

172

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

173

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

174

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 the 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 April 1 - June 30, 1997.

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

1997-12-31

175

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 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

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

1997-11-05

176

Dewatering of Deep Excavation in Gravity Aquifer in Puerto Rico Desagüe de Excavación Profunda en Acuífero Inconfinado en Puerto  

Microsoft Academic Search

Design of dewatering for an excavation into a gravity aquifer is discussed. The excavation for a pumping station was located 1,500 feet from the ocean and was successfully dewatered using seven high capacity deep wells. Falling head permeability tests in boreholes were conducted followed by various pumping tests used to predict aquifer behavior. Aquifer parameters were inferred from borehole tests

Rico Alan; R. Crumley

177

Mechanisms of floc destruction during anaerobic and aerobic digestion and the effect on conditioning and dewatering of biosolids  

Microsoft Academic Search

Laboratory anaerobic and aerobic digestion studies were conducted using waste activated sludges from two municipal wastewater treatment plants in order to gain insight into the mechanisms of floc destruction that account for changes in sludge conditioning and dewatering properties when sludges undergo anaerobic and aerobic digestion. Batch digestion studies were conducted at 20°C and the dewatering properties, solution biopolymer concentration

John T. Novak; Mary E. Sadler; Sudhir N. Murthy

2003-01-01

178

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

179

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

180

Sludge dewatering: sewage and industrial wastes. January 1978-January 1988 (citations from Pollution Abstracts). Report for January 1978-January 1988  

SciTech Connect

This bibliography contains citations concerning techniques and equipment used in sewage, and industrial, mining, petroleum and municipal waste-sludge dewatering. Dewatering processes, device design, and performance evaluations are considered. (This updated bibliography contains 233 citations, 51 of which are new entries to the previous edition.)

Not Available

1988-02-01

181

A Guide for Developing Standard Operating Job Procedures for the Sludge Conditioning & Dewatering Process Wastewater Treatment Facility. SOJP No. 11.  

ERIC Educational Resources Information Center

This guide describes standard operating job procedures for the sludge conditioning and dewatering process of wastewater treatment facilities. In this process, sludge is treated with chemicals to make the sludge coagulate and give up its water more easily. The treated sludge is then dewatered using a vacuum filter. The guide gives step-by-step…

Schwing, Carl M.

182

Experimental program for the development of peat gasification. Interim report No. 11. Solvent-extraction dewatering  

SciTech Connect

This interim report presents the results of tests conducted to determine the technical and economic feasibility of dewatering peat using a novel solvent extraction process developed by the Institute of Gas Technology (IGT). The process is based on a property of some solvents that causes their water solubility to increase significantly with temperature. Tests with selected solvents, conducted in a process development unit (PDU), were designed to determine the effects of temperature, residence time, and solvent recycling on the dewatering characteristics of peat. A literature review followed by a laboratory screening of the potential solvents narrowed the number of solvents to be tested in the PDU to five: n-butanol, amyl alcohol, benzene, methyl ethyl ketone (MEK), and diethyl ketone (DEK). A total of 37 tests were conducted at temperatures from 100/sup 0/ to 400/sup 0/F and residence times from 10 to 90 minutes with both pure and recycled solvents. Because the curve of water solubility versus temperature is specific for each solvent, appropriate operating conditions were selected for each solvent. DEK was selected as the solvent for preliminary economic evaluation. The results of the preliminary economic evaluation show that the dewatering cost (excluding peat harvesting costs) is very sensitive to solvent recovery efficiency. Increasing the solvent recovery efficiency from 95% to 100% decreased the dewatering product cost from about $3.00 to about $1.50/million Btu. Although the results of laboratory and PDU tests show that peat dewatering by the IGT solvent extraction process is technically feasible, a preliminary economic evaluation shows that it is not currently competitive with other dewatering methods.

Not Available

1982-07-01

183

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

184

Performance evaluation of a refitted hydraulic press using for water hyacinth dewatering  

Microsoft Academic Search

This article describes the design and construction of a refitted hydraulic press used for water hyacinth dewatering. The performance under different pressures of the press was investigated. The press system mainly composed five parts: support frame, round press plates, cylindrical sieve vessel, collection bucket and hydraulic power system. When the pressure increased from 10 MPa to 35 MPa, the residues

Xu Dayong

2010-01-01

185

Centrifugal dewatering and reconstitution of fine coal by the GranuFlow Process  

SciTech Connect

A continuous pilot-scale test of the GranuFlow Process was conducted using a screen-bowl centrifuge for the dewatering and reconstitution of column flotation concentrate at a coal preparation plant in Virginia. In this test, a slipstream of the fine-clean-coal slurry from the column flotation concentrate was treated with a bitumen emulsion before dewatering. The treated products from the screen-bowl centrifuge appeared to be dry and in a free-flowing granular form, while the untreated products were wet, sticky, and difficult to handle. Specifically, test results indicated that the average moisture contents of the dewatered coal were 35.7, 35.5, 32.6, 29.9, and 26.5 wt% with Orimulsion additions of 0, 0.7, 3.2, 4.8, and 6.4 wt%, respectively. The handleability and dust reduction of the dewatered coal product were also vastly improved. A preliminary cost estimate of using Orimulsion in the GranuFlow Process is also included. Because of the simplicity of the process and the low cost of the bitumen emulsion, the commercialization potential of the GranuFlow Process is significant.

Wen, W.W.; Utz, B.R.; Killmeyer, R.P. [Dept. of Energy, Pittsburgh, PA (United States). Federal Energy Technology Center

1997-12-31

186

The influence of particle size on energy consumption and water recovery in comminution and dewatering systems  

Microsoft Academic Search

Particle size is a key design variable in minerals beneficiation. Given declining grades in mineral ore reserves, finer grinding is being used to increase mineral liberation, leading to increased milling energy input. The particle size from the mill also has an effect on water recovery in downstream dewatering systems. This paper presents models for water recovery from the downstream thickening,

A. H. Mwale; P. Musonge; D. M. Fraser

2005-01-01

187

Effect of operating parameters and reagent addition on fine coal dewatering in a screen bowl centrifuge  

SciTech Connect

A six-inch continuous screen bowl centrifuge was employed in a pilot plant study designed to evaluate the effect of reagent addition, coal particle size distribution, slurry feed rate, and slurry feed solids concentration on the dewatering of finely ground Pittsburgh bed coal. The test results showed that 30%-solids slurry of minus-35-mesh coal could be dewatered to as low as 16% surface moisture with the addition of surfactant to the feed slurry. Without surfactant addition, the dewatered coal moisture level was about 20%. Similar tests with minus-200-mesh coal resulted in final product moisture levels of 21 to 23% with surfactant addition, and 25 to 27% without surfactant. With synthetic organic flocculant addition, on the other hand, the dewatered coal moisture content was always higher than without reagent. The increased moisture content appeared to be directly related to the molecular weight of the flocculant. Preparatory to the tests with reagents, several series of tests were run to evaluate the capacity of the centrifuge. These tests showed that feed rates greater than about 3 gal/min of 30%-solids slurry resulted in excessive coal losses in the effluent discharge. Ana feed slurry solids concentrations greater than about 30% at the 3 gal/min feed rate resulted in high product moisture content and excessive coal losses to the screen discharge. 10 references, 7 figures, 7 table.

Miller, K J; Wen, W W

1984-11-01

188

Magnetic fabrics from the Costa Rica margin: sediment deformation during the initial dewatering and  

E-print Network

Magnetic fabrics from the Costa Rica margin: sediment deformation during the initial dewatering; received in revised form 7 November 2002; accepted 8 November 2002 Abstract Drilling off of the Costa Rica. Ã? 2002 Elsevier Science B.V. All rights reserved. Keywords: underplating; Costa Rica; AMS

Housen, Bernie

189

DEWATERING OF IRON ORE MINES AND CAPABILITY TO PREDICT ENVIRONMENTAL IMPACTS - THE EXPERIENCE OF MBR  

Microsoft Academic Search

The Águas Claras and Mutuca iron ore mines, reached the watertable in the 80's, starting the dewatering by using series of deep wells. In the 90's, some communities located near the mines, complained about the possible interference in the stream's outflows and so, the areas covered by hydrogeological studies were enlarged in order to embrace the neighbourhood of the mines.

Leandro Quadros Amorim; Cesar Augusto; Paulino Grandchamp; Antônio Carlos Bertachini

2001-01-01

190

DEWATERING AT THE CAPÃO XAVIER IRON OPEN PIT MINE (MINAS GERAIS, BRAZIL)  

Microsoft Academic Search

Highly detailed hydrological and hydrogeological studies of the areas surrounding the Capão Xavier iron orebody, south of the city of Belo Horizonte (MG, Brazil), began in 1993. Dewatering of the aquifer in which the mineralization is located started in September, 2003, in advance of mining. Open pit mining of 220 million tonnes of ore, most of it below groundwater level,

RAFAEL FERNÁNDEZ RUBIO; CÉSAR GRANDCHAMP; LOBO DE REZENDE; DAVID LORCA FERNÁNDEZ

191

Optimization of slurry flocculation and dewatering based on electrokinetic and rheological phenomena  

Microsoft Academic Search

The use of chemical additives known as conditioners or flocculants is crucial in assuring the proper functioning of many solid-liquid separation processes, and dewatering in particular. The additive used is often a water soluble polymer with high molecular mass, strong adsorptive properties, and often a large amount of ionic charge. The type of polymer used, and its exact dose, may

Steven K Dentel; Mohammad M Abu-Orf; Christopher A Walker

2000-01-01

192

Effect of Processing Mode on Trace Elements in Dewatered Sludge Products  

Microsoft Academic Search

Minimization of the concentration and mobility of trace metals is a primary concern when considering the land application of wastewater sludges. The effects of pelletization\\/drying, composting, incineration, and N- Viro TM chemical stabilization on composition and mobility of trace metals and P were compared. A single day's production of dewatered anaerobically-digested sludge (Syracuse, NY) was used as the sole initial

Brian K. Richards; John H. Peverly; Tammo S. Steenhuis; Barry N. Liebowitz

1997-01-01

193

Simulation of Estuarine Flooding and Dewatering with Application to Great Bay, New Hampshire  

Microsoft Academic Search

A finite element model for simulating tidal flooding and dewatering of shallow estuaries is described and applications to hypothetical embayments and to the Great Bay, New Hampshire estuary system, are presented. The model incorporates two-dimensional kinematic wave physics, with a porous medium beneath the open channel to incorporate the realistic drainage of dry elements on a fixed, high resolution mesh.

J. T. C. Ip; D. R. Lynch; C. T. Friedrichs

1998-01-01

194

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...

195

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

196

Development of an improved synthetic sludge: a possible surrogate for studying activated sludge dewatering characteristics  

Microsoft Academic Search

Activated sludge is a complex mixture of inert suspended solids, various microorganisms, and extracellular material. Research on the physical characteristics of activated sludge is complicated because the living microorganisms continuously change sludge characteristics, making it almost impossible to carry out controlled experiments or reproduce test results. Therefore, in dewatering, settling and conditioning studies of activated sludge, there is a clear

Banu Örmeci; P. Aarne Vesilind

2000-01-01

197

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 ...

198

Impact of dewatering technology on the cost of drilling-waste disposal  

SciTech Connect

The use of mobile, chemically enhanced centrifugation dewatering systems to process liquid waste from two deep exploratory wells in Kern County, CA, saved $136,900 in waste-disposal costs. Liquid waste in the wells was reduced by {approx}45%. This paper tracks daily costs and chemical usage for each well to isolate key cost factors.

Malachosky, E. (Arco Oil and Gas Co. (US)); Sanders, R. (Arco British Ltd. (GB)); McAuley, L. (GeoWestern Drilling Fluids (US))

1991-06-01

199

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

200

Laboratory studies on geotextile filters as used in geotextile tube dewatering  

Microsoft Academic Search

This study is concerned with geotextile filtration as an alternative for conventional disposal methods adopted for the disposal of high water content wastes. In this study, 42 dewatering tests using geotextiles of four different opening sizes were conducted on harbour sediment and fly ash to study the individual influence of factors like water content, gradation of solids, and opening size

A. E. Muthukumaran; K. Ilamparuthi

2006-01-01

201

Distribution of water in sludges in relation to their mechanical dewatering  

Microsoft Academic Search

The water content of a sludge is generally considered to be constituted by two fractions: free water and bound water. This classification does not, however, characterize the binding energy of water to the solid phase. By using the dilatometric technique, the bound water content of sludge was measured as a function of the mechanical dewatering strain applied to the sludge.

F. Colin; S. Gazbar

1995-01-01

202

Hydrologic considerations in dewatering and refilling Lake Carlton : Orange and Lake Counties, Florida  

USGS Publications Warehouse

Lake Carlton straddles the line between Lake and Orange Counties in central Florida. The 382-acre lake is highly eutrophic and subject to virtually perpetual algal blooms. The Florida Game and Fresh Water Fish Commission has proposed to restore the lake to a less eutrophic state by dewatering the lake long enough to allow the muck on its bottom to dry and compact. Lake Carlton would be permanently sealed off from Lake Carlton. On the assumption that the seasonal rainfall would be normal, and that the dewatering phase would begin on March 1, the predicted time required to dewater the lake at a pumping rate of 50,000 gpm (gallons per minute) is 21 days. The average rate of pumping required to maintain the lake in a dewatered condition is computed to be 2,400 gpm. If pumping is ended May 31, the predicted altitude to which the lake would recover by October 31 as a result of net natural input is 56.2 feet above sea level. Raising the lake level to 63 feet above sea level by October 31 would require that the net natural input be supplemented at an average rate of about 4,860 gpm between May 31 and October 31. (Woodard-USGS)

Anderson, Warren; Hughes, G. H.

1977-01-01

203

Physicochemical characteristics of full scale sewage sludges with implications to dewatering  

Microsoft Academic Search

An investigation was carried out for a variety of different sewage sludges in order to establish correlations between sludge composition, structure and dewatering properties. Results indicated that the fraction of extracellular polymeric substances (EPS) in sludges was the most important parameter with respect to sludge structure. With high EPS contents, sludges had a lower shear sensitivity and lower degree of

Lene Haugaard Mikkelsen; Kristian Keiding

2002-01-01

204

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

205

Charge-tunable polymers as reversible and recyclable flocculants for the dewatering of microalgae.  

PubMed

Microalgae-derived biofuels have potential advantages over other renewable, crop-based resources; however, large-scale production is not currently economical due, in part, to challenges in the harvesting step. In this article, we present a novel approach for the dewatering and harvesting of microalgae using flocculants that can be recovered and recycled. Polyampholytes with molecular charges dependent upon pH (ranging from net positively- to net negatively-charged) are used as a model flocculant system and provide reversible electrostatic interactions with the negatively-charged algal cells. These pH-dependent properties allow the polyampholytic flocculants to efficiently desorb from concentrated biomass and, unlike most commercial flocculants that have permanently charged functionalities, be recovered and recycled for further dewatering processes. The behavior of the model polyampholytic flocculants is characterized for the dewatering of Chlorella vulgaris (UTEX 395). The reversible and recyclable flocculants achieve >99% flocculation efficiencies, are recovered at more than 98?wt% yields after biomass dewatering, and can be recycled over five times for flocculation. Biotechnol. Bioeng. 2015;112: 74-83. © 2014 Wiley Periodicals, Inc. PMID:25060233

Morrissey, Kathryn L; He, Chunlin; Wong, Min Hao; Zhao, Xueying; Chapman, Rebeccah Z; Bender, Shana L; Prevatt, William D; Stoykovich, Mark P

2015-01-01

206

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

207

Field Demonstration of the Performance of a Geotube® Dewatering System to Reduce Phosphorus and Other Substances from Dairy Lagoon Effluent  

E-print Network

which called for the reduction of annual loading and annual average soluble reactive P (SRP) concentrations by about 50%. This demonstration was conducted to evaluate the efficacy of a prospective new technology, the Geotube® dewatering system that may...

Mukhtar, Saqib; Wagner, Kevin; Gregory, Lucas

208

Electroosmotically enhanced dewatering/deliquoring of fine-particle coal: Final report, January 1--December 31, 1988  

SciTech Connect

This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coal are inadequate and generally require subsequent thermal drying. Thermal drying is not only expensive and time consuming, it also does not recover liquids for reuse in beneficiation processes. The degree of difficulty associated with dewatering increases as surface forces become more important than gravimetric forces. Electroosmotic flow has advantages for dewatering because it is much less sensitive to pore size than hydraulic gradient flow for the 1 to 75 ..mu..m ultrafine size range. The first year of this project focused upon preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. Techniques and procedures not previously used by researchers of electroosmotic dewatering have revealed important information about the dynamics of the electroosmosis process. The identification of the first few millimeters of the cathode region of the cell as the sink for most of the energy input into the process provides the potential for improving efficiency by concentrating the second year effort on intervention in that region. Information gathered about differences in FTIR spectra as a function of location in the dewatering cell will be investigated. Changes in pH with temperature and by the application of electroosmotic current flow will receive attention, as well. 178 refs., 16 figs.

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

1989-03-01

209

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

DOEpatents

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 (Murrysville, PA); Gray, McMahan L. (Pittsburgh, PA); Champagne, Kenneth J. (Finleyville, PA)

1995-01-01

210

Coal waste dewatering systems. Open file report 11 December 1979-6 February 1981  

SciTech Connect

Samples of fine coal refuse were obtained from 11 coal preparation plants throughout the United States. The samples were characterized by ash analysis, particle size, and mineral composition. From the characterization, geographical locations, and the dewatering equipment being used by the plants, five sites were selected for obtaining bulk fine refuse samples. The selected coal preparation plants were used for final dewatering thickeners followed by a vacuum disc filter, a filter press, a belt press filter, a centrifuge, and a settling pond. None were using thermal drying. The moisture content of the final cake ranged from approximately 23 to 50 pct, depending upon the feed material, flocculant addition, and the type of equipment. The filter press gave the lowest moisture content followed by a belt press and then either a centrifuge or vacuum filter. The centrifuge products were all dried to an approximate 5-pct moisture in a thermal dryer.

Jacobsen, S.P.; Roushey, W.; Rau, E.L.

1981-02-01

211

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

212

An investigation of operating variables in the fine coal dewatering and briquetting process  

SciTech Connect

Illinois basin coals contain minerals, including pyrite, which are finely disseminated in micron-size particles. To liberate these mineral matters from the coal matrix, an ultra-fine grinding operation is required, followed by a wet physical cleaning process, such as column flotation. However, the resulting product possesses large surface areas that conventional dewatering techniques cannot perform effectively, and this creates transportation, storage and handling problems at utility plants. To take full advantage of these cleaning technologies, a new dewatering and coal consolidation method must be developed at the downstream end of the deep coal-cleaning process. Following an initial study at the University of Missouri-Rolla (UMR), briquetting was chosen to perform the dual purpose of dewatering and consolidating the fine coal. A bitumen-based emulsion, Orimulsion, proved to be an effective binder and dewatering agent in the briquetting process that assisted in the expulsion of water from the fine coal. This paper describes the investigation aimed at examining the relationships between several controllable operating variables. An experimental matrix was designed to examine a range of operating parameters based on earlier work conducted at the Department of Mining Engineering, University of Missouri-Rolla. A total of 13 experiments were performed using Illinois No. 6 coal samples that had a size fraction of 16 mesh x 0 and a moisture content of 31%. Based on results obtained from previous experiments and because of the complexity of the briquetting process, only two variables, roll speed and the briquetting form pressure, were studied for their influence on moisture content, abrasion resistance and friability of briquettes. Concurring with results from previous work, the curing time of the briquettes formed had a significant impact on the moisture content and friability of the compacted fine coal product. Also, the statistical regression models generated from these results successfully established basic relationships between the operating parameters of roll speed and briquette form pressure.

Kan, S.W.; Wilson, J.W.; Dharman, T.

1998-07-01

213

Electrokinetically enhanced flow and dewatering characteristics of concentrated black coal-water suspensions in pipes  

SciTech Connect

The transportability and dewatering of coal-water mixtures flowing in a pipe may be enhanced by the application of electrokinetic techniques. Previous experimental work by other workers shows a significant reduction in the wall shear stress, and consequently a decrease in pumping energy requirements for the flow of coal-water mixtures in pipes combined with electrodewatering. In this process the pipe wall acts as the cathode and a centrally aligned tube as the anode. The effects of {open_quote}In-pipe electrodewatering{close_quote} on the flow properties and stability of concentrated coal-water mixtures flowing in various alternative anode-cathode arrangements are presented in this paper. The application of an electrical energy flux at the electrode surface (< 6.1 kW/m{sup 2}) in a dewatering section of pipe (L{sub e}=1m) effectively reduces the pumping energy requirements by as much as one order of magnitude. The stability of flow conditions is investigated in a concentric anode-cathode pipe arrangement consisting of a dewatering and a non-dewatering section (L{sub o}). In this system (L{sub o}/L{sub e}) < 4.0. A microscopic study of dilute coal-water suspensions in the presence of a DC electric field revealed the migration of coal particles towards the anode and the structural formation of coal particle chains. The electrorheological behaviour of concentrated coal-water suspensions is examined with the use of a modified coaxial rheometer. The coal fines (d{sub 50}=17.7{mu}m) used in all experiments were produced by milling a low rank bituminous black coal which was followed by a sieving process that eliminated coal particles that were greater than 75{mu}m in size.

Rozakeas, P.K.; Snow, R.J. [Royal Melbourne Inst. of Technology, Victoria (Australia)

1997-07-01

214

Evaluation of solids dewatering for a pilot-scale thiosorbic lime SO/sub 2/ scrubber  

SciTech Connect

Pilot plant data showed that the dissolved magnesium in thiosorbic lime caused deterioration of solids dewatering properties. The slurry settling rate increased when the slurry shear stresses caused by the hold tank stirrer and recirculation pump were reduced. The application of flocculant also increased the slurry solids settling rate. Compared with rotary drum vacuum filtering, better liquid/solids separation occurred with a centrifuge. Other related performance results are also discussed.

Chang, J.C.S.; Brna, T.G.

1987-01-01

215

The Challenges of Dewatering at the Victor Diamond Mine in Northern Ontario, Canada  

Microsoft Academic Search

The costs and efficiency of dewatering are particularly important at De Beers Canada’s Victor diamond mine in northern Ontario,\\u000a where the bottom of the water-bearing carbonate country rocks is near the bottom of the planned pit, which limits the available\\u000a drawdown in the perimeter wells. Most of the inflow to the wells comes from a limited number of discrete zones

L. C. AtkinsonP; J. C. Wright; Houmao Liu

2010-01-01

216

Determination of filtration and dewatering parameters of sediments in industrial filters  

Microsoft Academic Search

Basic equations (laws) of various filtration processes (with the formation of sediment, intermediate, and standard laws, filtration\\u000a with decreasing number of open pores in the filter), as well as equations for determination of dewatering parameters are examined.\\u000a As an example, optimal operating regimes of a vaccum disk filter were defined via computer for determination of the law and\\u000a parameters of

E. V. Shiryaeva; Yu. V. Gutin; A. A. Aksenov

2008-01-01

217

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

Microsoft Academic Search

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 combination with a long-chain polymer flocculation aid (HyChem CE 1950 at 25mg\\/L) to determine the most cost effective and efficient treatment combination.

Mark J. Sharrer; Kata Rishel; Steven Summerfelt

2009-01-01

218

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

219

Thermochemical liquidization of anaerobically digested and dewatered sludge and anaerobic retreatment  

Microsoft Academic Search

The pretreatment effect of thermochemical liquidization for the anaerobic retreatment of anaerobically digested and dewatered sludge was studied. The digested sludge (dry matter; 15.7%) was thermochemically liquidized at 175°C and 4 MPa with a holding time of 1 h. The liquidized sludge was separated by centrifugation to produce a supernatant of 44.7% (w\\/w) and precipitate of 52.3%. The liquidized sludge

Shigeki Sawayama; Seiichi Inoue; Kenichiro Tsukahara; Tomoko Ogi

1996-01-01

220

Influence of pH on the dewatering of activated sludge by Fenton's reagent  

Microsoft Academic Search

The specific filtration resistance, moisture, and SVI were used to evaluate the influence of pH on the filtration and dewatering efficiencies when applying Fenton's reagent to treat the excess sludge. The excess sludge used in this study was obtained from the wastewater treatment plant of An-Ping Industrial Park in Tainan, Taiwan. Results show that initial pH has no significant effect

M.-C. Lu; J. Lin; C.-H. Liao; W.-P. Ting; R.-Y. Huang

2001-01-01

221

Optimization of the use of polyelectrolytes for dewatering industrial sludges of various origins  

Microsoft Academic Search

Four different industrial slurries were flocculated with polymeric flocculating agents (port sediment, sewage sludge, sugar\\u000a beet washings and an aluminum hydroxide suspension). The quantities of flocculating agent employed were optimized with the\\u000a aid of a patented, portable flocculation and dewatering apparatus. Using sewage sludge as an example, it was possible to arrive\\u000a at predictions for particular doses of flocculating by

N. Böhm; W.-M. Kulicke

1997-01-01

222

Use of coking-plant products to intensify dewatering processes in vacuum filters  

SciTech Connect

The extensive mechanization of coal mining is leading to serious coal crushing, with the result that the proportion of the wettest washery products (such as flotation concentrates) in coke-oven blends has risen to 30 to 35% and the over-all moisture content to 11 to 12%; these values are tending to increase still further. Consequently, interest has increased in the development and adoption of effective methods of mechanical dewatering, both here and in other countries. One particularly interesting topic is the search for surfactants capable of increasing the efficiency of dewatering processes and maximizing the performance of equipment already installed in coal washeries. Much interest has been aroused in additives which do not dissolve in water, for example petroleum or coal-tar oils. We have tried to make oil additions more effective by increasing the surface area of the oil bubbles, by emulsification in the water. The oiling substance we used was anthracene oil, while the emulsifier was a neutralized acid sludge from the benzol rectification shop in the coking plant. It was found that: 1. anthracene oil and various other coking-plant products intensify the dewatering process when added at the rate of 3 to 5 kg/ton; they additionally lower the moisture content of vacuumfilter cake by 3 to 5%. 2. Neutralized acid sludge from the sulfuric acid washing of benzol can be recommended as an emulsifier to form stable coal-tar oil emulsions in water.

Belov, K.A.; Karnozhitskii, P.V.; Selyanko, I.T.; Ustinovskaya, S.A.; Kovtunenko, E.N.; Mosin, M.K.; Ivashchenko, F.A.

1981-01-01

223

Prediction of full-scale dewatering results of sewage sludges by the physical water distribution.  

PubMed

The dewaterability of sewage sludge can be described by the total solids concentration of the sludge cake and the polymer-demand for conditioning. The total solids concentration of the sludge cake depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by the type and the intensity of their physical bonding to the solids. In a sewage sludge suspension four different types of water can be distinguished. These are the free water, which is not bound to the particles, the interstitial water, which is bound by capillary forces between the sludge flocs, the surface water, which is bound by adhesive forces and intracellular water. Only the share of free water can be separated during mechanical dewatering. It can be shown, that by thermo-gravimeteric measurement of the free water content, an exact prediction of full-scale dewatering results is possible. By separation of all free water during centrifugation the maximum dewatering result is reached. Polymer conditioning increases the velocity of the sludge water release, but the free water content is not influenced by this process. Furthermore it is not possible, to replace the measuring of the water distribution by other individual parameters such as ignition loss. PMID:11443955

Kopp, J; Dichtl, N

2001-01-01

224

Model analysis of effects on water levels at Indiana Dunes National Lakeshore caused by construction dewatering  

USGS Publications Warehouse

The computer models were developed to investigate possible hydrologic effects within the Indiana Dunes National Lakeshore caused by planned dewatering at the adjacent Bailly Nuclear Generator construction site. The model analysis indicated that the planned dewatering would cause a drawdown of about 4 ft under the westernmost pond of the Lakeshore and that this drawdown would cause the pond to go almost dry--less than 0.5 ft of water remaining in about 1 percent of the pond--under average conditions during the 18-month dewatering period. When water levels are below average, as during late July and early August 1974, the pond would go dry in about 5.5 months. However, the pond may not have to go completely dry to damage the ecosystem. If the National Park Service 's independent study determines the minimum pond level at which ecosystem damage would be minimized, the models developed in this study could be used to predict the hydrologic conditions necessary to maintain that level. (Woodard-USGS)

Marie, James R.

1976-01-01

225

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

226

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

227

Dewatering: Coal and mineral processing. January 1970-March 1990 (A Bibliography from the COMPENDEX data base). Report for January 1970-March 1990  

SciTech Connect

This 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 published bibliographies. (Contains 173 citations fully indexed and including a title list.)

Not Available

1990-05-01

228

Evaluation of hyperbaric filtration for fine coal dewatering. Sixth quarterly technical progress report, 1 January--31 March 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 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. Progress to date is described.

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

1994-06-01

229

ADEWA - Keinotekoinen vedenpoisto turpeesta. Energiatutkimusohjelman loppuraportti 1988-1992. (ADEWA - Artificial dewatering of peat. Final report on the energy research programme 1988-1992).  

National Technical Information Service (NTIS)

A peat production method (SLURRY-COMP) based on artificial dewatering was developed according to the aims of the research programme. The most important subgoal was to obtain dry solid content of 35 % in mechanical dewatering. A peat layer of 0.3-0.4 m is ...

P. Pirkonen

1993-01-01

230

Sludge dewatering: Sewage and industrial wastes. January 1978-December 1989 (A Bibliography from Pollution Abstracts). Report for January 1978-December 1989  

SciTech Connect

This bibliography contains citations concerning techniques and equipment used in sewage, as well as industrial, mining, petroleum, and municipal-waste sludge dewatering. Dewatering processes, device design, and performance evaluations are considered. (This updated bibliography contains 266 citations, 12 of which are new entries to the previous edition.)

Not Available

1990-03-01

231

Bacterial pathogen indicators regrowth and reduced sulphur compounds' emissions during storage of electro-dewatered biosolids.  

PubMed

Electro-dewatering (ED) increases biosolids dryness from 10-15 to 30-50%, which helps wastewater treatment facilities control disposal costs. Previous work showed that high temperatures due to Joule heating during ED inactivate total coliforms to meet USEPA Class A biosolids requirements. This allows biosolids land application if the requirements are still met after the storage period between production and application. In this study, we examined bacterial regrowth and odour emissions during the storage of ED biosolids. No regrowth of total coliforms was observed in ED biosolids over 7d under aerobic or anaerobic incubations. To mimic on-site contamination during storage or transport, ED samples were seeded with untreated sludge. Total coliform counts decreased to detection limits after 4d in inoculated samples. Olfactometric analysis of ED biosolids odours showed that odour concentrations were lower compared to the untreated and heat-treated control biosolids. Furthermore, under anaerobic conditions, odorous reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) were produced by untreated and heat-treated biosolids, but were not detected in the headspaces above ED samples. The data demonstrate that ED provides advantages not only as a dewatering technique, but also for producing biosolids with lower microbial counts and odour levels. PMID:25065797

Navab-Daneshmand, Tala; Enayet, Samia; Gehr, Ronald; Frigon, Dominic

2014-10-01

232

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

NASA Astrophysics Data System (ADS)

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 of the leach residues were investigated with the aid of settling rate, supernatant turbidity, and slurry filtrability measurements. The polymeric flocculants were found to be effective in improving the dewatering properties of the acid leach residues. Polymer effectiveness increased with increasing polymer dosage for all the polymers, but an optimum polymer dose was only found for polymer A (34 pct anionic, 11×106 mol wt) in the studied range of polymer addition. Similarly, the dewatering behavior was improved at higher polymer molecular weight. In addition, it was found that the flocculation performance was adversely affected by an increase in the degree of polymer hydrolysis which, in turn, increases the ratio of carboxylic to amide functional groups in the polymer chain. Polymer C (nonionic ˜0 pct hydrolysis, 13.5×106 mol wt) was found to be the most efficient flocculant in terms of all the performance criteria investigated. The preceding results were rationalized in terms of bridging flocculation, the ionization and molecular configuration of the polymers, hydrogen bonding, and the solid/aqueous interfacial charge.

Briceno, A.; Osseo-Asare, K.

1995-02-01

233

Biodiesel from dewatered wastewater sludge: a two-step process for a more advantageous production.  

PubMed

Alternative approaches for obtaining biodiesel from municipal sludge have been successfully investigated. In order to avoid the expensive conventional preliminary step of sludge drying, dewatered sludge (TSS: 15wt%) was used as starting material. The best performance in terms of yield of fatty acid methyl esters (18wt%) with the lowest energy demand (17MJkgFAME(-1)) was obtained by a new two-step approach based on hexane extraction carried out directly on dewatered acidified (H2SO4) sludge followed by methanolysis of extracted lipids. It was found that sulphuric acid plays a key role in the whole process not only for the transesterification of glycerides but also for the production of new free fatty acids from soaps and their esterification with methanol. In addition to biodiesel production, the investigated process allows valorization of primary sludge as it turns it into a valuable source of chemicals, namely sterols (2.5wt%), aliphatic alcohols (0.8wt%) and waxes (2.3wt%). PMID:23642459

Pastore, Carlo; Lopez, Antonio; Lotito, Vincenzo; Mascolo, Giuseppe

2013-07-01

234

Rapid dewatering of the crust deduced from ages of mesothermal gold deposits  

USGS Publications Warehouse

The large-scale migration of fluids through the continental crust has been well documented, but there is no consensus regarding the timing of fluid migration relative to erogenic episodes, or rates of crustal dewatering1. Here we present 40Ar/39Ar dates for muscovites from quartz veins along a major shear zone in southeast Alaska, which show that the veins were emplaced in the early Eocene, during the late stages of orogenic deformation. Hydrothermal activity took place for only about 1 Myr and along a distance of at least 200 km. The fluids were generated by metamorphic reactions in subducted crust along the North American plate margin, and were apparently trapped in the crust by the low permeabilities accompanying a convergent tectonic regime until 56 Myr ago. The rapid dewatering event coincided with a change in plate motion at 56-55 Myr, which caused a shift from convergent to partly transcurrent tectonics. We suggest that this change in tectonic regime led to increased crustal permeabilities and hence the possibility of large-scale fluid migration.

Goldfarb, R. J.; Snee, L. W.; Miller, L. D.; Newberry, R. J.

1991-01-01

235

Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.  

PubMed

Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties were determined using multivariate analysis. Chemical characterisation included basic sludge analysis, elementary analysis and analysis of wood-based components, such as hemicelluloses and lignin-derived material. Dewatering properties were determined using measurements of dry solids content, flux and flocculant dosage. The effects of different variables varied according to the response concerned. The variables which were significant regarding cake DS increase in filtration or centrifugation and flocculant dosage needed in filtration were different from those which were significant regarding flux. PMID:20651444

Kyllönen, H; Lehto, J; Pirkonen, P; Grönroos, A; Pakkanen, H; Alén, R

2010-01-01

236

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

Microsoft Academic Search

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 as a result of load-following operations and subsequent changes in water surface elevation before the fry emerge. To determine whether fall Chinook salmon redds in a shallow area subjected

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

2005-01-01

237

Tolerance of eggs, embryos, and alevins of chinook salmon to temperature changes and reduced humidity in dewatered redds  

Microsoft Academic Search

Changes in temperature and relative humidity can occur in gravel during dewatering of salmonid redds. Four intergravel development phases of chinook salmon Oncorhynchus tshawytscha were exposed to increased or decreased temperatures, and one phase was subjected to reduced relative humidity to define tolerance limits. Abrupt increases in temperature from 10C to above 22C for 1-8 h reduced survival of cleavage

DUANE A. NEITZEL; C. DALE BECKER

1985-01-01

238

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

239

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

240

Overview: full scale experience of the SHARON® process for treatment of rejection water of digested sludge dewatering  

Microsoft Academic Search

A SHARON® system has been constructed at the Utrecht WWTP and at the Rotterdam Dokhaven WWTP. In the SHARON® process rejection water from dewatering of digested sludge is treated for N-removal. It concerns a high active process operating without sludge retention. Due to differences in growth rate nitrite oxidisers can be washed out of the system while ammonia oxidisers are

R. van Kempen; J. W. Mulder; C. A. Uijterlinde; M. C. M. Loosdrecht

2001-01-01

241

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

242

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

243

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

244

Hydrothermal treatment coupled with mechanical expression at increased temperature for excess sludge dewatering: influence of operating conditions and the process energetics.  

PubMed

Dewatering is very important for excess sludge treatment and disposal. Hydrothermal treatment coupled with mechanical expression is a novel technology, in which a conventional pressure dewatering is combined with hydrothermal effect to realize an improved liquid/solids separation with low energy consumption. In this study, the process was performed by way of that the excess sludge was hydrothermally treated first and then the mechanical expression was employed immediately at increased temperature in two separate cells respectively. The results demonstrated that the mechanical expression employed at increased temperature showed a significant advantage than that at room temperature, given a further reduction of 19-47% of the moisture content. The dewatering process at room temperature was mostly depended on the effect of mechanical expression. Hydrothermal process, more importantly than mechanical effect at increased temperatures, seemed to govern the extent to which the dewatering process occurred. The dewatering began to show a positive effect when the temperature was exceeded the threshold temperature (between 120 and 150 °C). The residence time of 30 min promoted a substantial conversion in the sludge surface properties. After dewatering at temperatures of 180-210 °C, the moisture content decreased from 52 to 20% and the corresponding total water removal as filtrate was between 81 and 93%. It was observed that the moisture content of filter cake correlated with surface charge (Rp = -0.93, p < 0.05) and relative hydrophobicity (Rp = -0.99, p < 0.05). The calculated energy balance suggested that no additional external energy input is needed to support the dewatering process for excess sludge. The dewatering process needs an obviously lower energy input compared to thermal drying and electro-dewatering to produce a higher solids content cake. PMID:25090626

Wang, Liping; Zhang, Lei; Li, Aimin

2014-11-15

245

A study of a solvent/binder combination for viscosity reduction of Orimulsion in fine coal dewatering  

SciTech Connect

To effectively liberate finely disseminated minerals from a coal matrix, a pulverization operation is needed. In this process fine coal particles are formed that possess large surface areas that are difficult to dewater, and create transportation, storage and handling problems at coal cleaning and utility plants. Using both laboratory and pilot scale models, research work conducted at the Department of Mining Engineering at University of Missouri-Rolla (UMR) on a single-state fine coal dewatering and briquetting technique, has shown the potential of briquetting to enhance the handling, transportation, and storage of fine coal. The operation uses a hydrophobic binder as the dewatering and briquetting agent and requires a compaction device, specifically, a commercial-scale briquetting machine. In the single-state dewatering-briquetting process, a bitumen-in-water emulsion (Orimulsion), which has high viscosity even at room temperature, was selected as the binder. Due to the tacky nature of the binder, it was felt that by reducing its viscosity using a solvent, the binder could more effectively coat the fine coal surfaces. This study investigated the efficiency of a solvent/binder combination for reducing the viscosity of the Orimulsion for the dewatering of fine coal, and making robust briquettes from predominantly -400 mesh coal particles. Preliminary results indicated that by adding a solvent to the binder, it reduced the viscosity of the Orimulsion, which in turn provided a more efficient use of the binder and resulted in a better coating of the ultra-fine coal particles. Using multiple-variable linear regression analyses, it was possible to establish basic relationships between the change in moisture of coal pellets and several operating variables. The model showed that the compaction pressure, as well as the type and amount of solvent used in conjunction with Orimulsion, influenced the moisture content of the coal pellets produced.

Kan, S.W.; Wilson, J.W.; Dharman, T.; Aksoy, B.S.

1998-07-01

246

Numerical simulations of episodic basin dewatering around a salt dome and the formation of thermal and brine plumes  

SciTech Connect

Numerical simulations of coupled heat and dissolved salt transport in groundwater were run using the code PORFLOW to study temperatures, salinities, and fluid pressures resulting from episodic basin dewatering around a generic salt dome. The model consisted of a salt dome 2 km below the surface encircled by an annular permeable conduit 100 m wide. The dome and conduit were surrounded by a 10 km thick sedimentary section with the lower 7 km of sediment initially geopressured. The geopressured section was allowed to deflate by expelling waters radially inward to the flank of the dome and then vertically up the conduit along the salt-sediment interface. Episodic dewatering was modeled through cyclic changes in the conduit permeability. During a dewatering event lasting 20 thousand years, kilometer-scale thermal and brine plumes formed above and along the dome. The thermal plume raised temperatures up to 80 C above pre-existing conduction values. With the conduit sealed, the thermal plume mostly dissipated in 100 thousand years and the brine plume sank below the dome within 300 thousand years. Substantial pressure loss occurred during the dewatering events with relatively small pressure losses when the conduit was sealed. The results of these simulations show that episodic basin dewatering is a viable mechanism for transporting hot brines to the top of a salt dome as previously proposed in the formation of metallic sulfide band s observed in some salt dome cap rocks. It is also capable for forming brine plumes similar to that above Welsh dome in Louisiana while maintaining overpressure for millions of years.

Williams, M.D.; Ranganathan, V. (Indiana Univ., Bloomington, IN (United States). Dept. of Geological Sciences)

1992-01-01

247

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

248

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

249

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

250

Vacuum and pressure expression dewatering of fine coal and refuse using a belt filter press  

SciTech Connect

Vacuum dewatering was found to be sufficient for coarse size fractions of fine coal (top size 400 mesh) and vacuum plus pressure expression dewatering was effective only for the ultra-fine coal (average size 10 {mu}m). For fine coal refuse however, both vacuum and pressure expression were observed to be necessary to obtain better cake filterability and lower cake moisture content. Several flocculants having different ionic activities, molecular weights and chemical compositions were tested. For fine coal refuse, nonionic flocculants in the medium molecular weight range of 4-5 million were found to be most effective in terms of lower cake formation time (filterability) and final moisture content. The performance of an anionic flocculant in the same molecular weight range was not as good as the nonionic flocculant. In the higher molecular weight range (10-15 million) the effect of ionic properties was negligible and all three types (anionic, cationic, nonionic) were equally effective. The effect of mixing conditions on flocculation of coal refuse slurry was investigated for selected flocculants. The effect of surfactants on the final moisture content of coal refuse cake was significant. The effect of belt speed on final moisture content was negligible indicating that expression was complete even at higher speeds. The effects of solid addition and solids concentration, on final moisture content and cake formation time were investigated. The compressive force present in the belt filter press was measured by various techniques including a miniature pressure transducer, pressure sensitive film and force sensing resistors. An empirical correlation for estimation of actual pressure as a function of applied hydraulic pressure was developed.

Badgujar, M.N.

1988-01-01

251

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

National Technical Information Service (NTIS)

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...

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

1997-01-01

252

Production of green juice with an intensive thermo-mechanical fractionation process. Part I: Effects of processing conditions on the dewatering kinetics  

Microsoft Academic Search

The thermally assisted mechanical dewatering (TAMD) process is a new intensive solid\\/liquid separation device. When applied to ‘nature-wet’ biomass, the TAMD process significantly enhances the separation yield. The TAMD process couples in one stage a mechanical dewatering at low pressure (Papplied=300kPa in the present study) with a moderated heating (Twall?90°C). An increment of pressure can be applied in a second

P. Arlabosse; M. Blanc; S. Kerfaï; A. Fernandez

2011-01-01

253

Involvement of Gypsum (CaSO4 · 2H2O) in Water Treatment Sludge Dewatering: A Potential Benefit in Disposal and Reuse  

Microsoft Academic Search

This research assessed the use of gypsum (CaSO4 · 2H2O) as a skeleton builder for sludge dewatering since polymer conditioning of sludge affected only the rate of water release, not the extent of dewatering. The use of gypsum as a physical conditioner, in association with a polymer, could improve sludge filterability. More significantly, gypsum serves as a skeleton builder, forming a permeable

Y. Q. Zhao

2006-01-01

254

Development of the Electroacoustic Dewatering (EAD) process for fine/ultrafine coal: First quarterly progress report, period ending December 15, 1988  

SciTech Connect

Battelle, in cooperation with the Electric Power Research Institute (EPRI), Ashbrook-Simon-Hartley (ASH), Kaiser Engineers (KE), Lewis Corporation, and Prof. S.H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine and ultrafine coals. The advanced process, called Electroacoustic Dewatering (EAD), capitalizes on the adaptation of synergistic effects of electric and acoustic fields to a commercial belt filter press design that is used in many other applications. 1 fig.

Not Available

1989-01-05

255

Transport phenomena in the crystallization of lysozyme by osmotic dewatering and liquid-liquid diffusion in low gravity  

NASA Technical Reports Server (NTRS)

Two methods of protein crystallization, osmotic dewatering and liquid-liquid diffusion, like the vapor diffusion (hanging-drop and sessile-drop) methods allow a gradual approach to supersaturation conditions. The crystallization of hen egg-white lysozyme, an extensively characterized protein crystal, in the presence of sodium chloride was used as an experimental model with which to compare these two methods in low gravity and in the laboratory. Comparisons of crystal growth rates by the two methods under the two conditions have, to date, indicated that the rate of crystal growth by osmotic dewatering is nearly the same in low gravity and on the ground, while much faster crystal growth rates can be achieved by the liquid-liquid diffusion method in low gravity.

Todd, Paul; Sportiello, Michael G.; Gregory, Derek; Cassanto, John M.; Alvarado, Ulises A.; Ostroff, Robert; Korszun, Z. R.

1993-01-01

256

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

257

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

258

Membrane-based energy efficient dewatering of microalgae in biofuels production and recovery of value added co-products.  

PubMed

The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. The dewatering of Nannochloropsis sp. was evaluated 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, 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. PMID:22510094

Bhave, Ramesh; Kuritz, Tanya; Powell, Lawrence; Adcock, Dale

2012-05-15

259

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

260

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

261

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

2012-10-01

262

Engineering development of advanced physical fine coal cleaning for premium fuel applications: Subtask 3.3 - dewatering studies  

SciTech Connect

If successful, the novel Hydrophobic Dewatering (HD) process being developed in this project will be capable of efficiently removing moisture from fine coal without the expense and other related drawbacks associated with mechanical dewatering or thermal drying. In the HD process, a hydrophobic substance is added to a coal-water slurry to displace water from the surface of coal, while the spent hydrophobic substance is recovered for recycling. For this process to have commercialization potential, the amount of butane lost during the process must be small. Earlier testing revealed the ability of the hydrophobic dewatering process to reduce the moisture content of fine coal to a very low amount as well as the determination of potential butane losses by the adsorption of butane onto the coal surface. Work performed in this quarter showed that the state of oxidation affects the amount of butane adsorbed onto the surface of the coal and also affects the final moisture content. the remaining work will involve a preliminary flowsheet of a continuous bench-scale unit and a review of the economics of the system. 1 tab.

Yoon, R.H., Phillips, D.I., Sohn, S.M., Luttrell, G.H. [Virginia Polytechnic Inst. and State Univ., Center for Coal and Mineral Processing, Blacksburg, VA (United States)

1996-10-01

263

Evaluation of hyperbaric filtration for fine coal dewatering. Fourth quarterly technical progress report: June 1, 1993--September 30, 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 1, the University of Kentucky in Phase 2, and Consol Inc. in Phase 3 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 1 and 2 will be tested in a Consol Inc. coal preparation plant 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., Library, PA (United States)

1993-12-31

264

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

265

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

266

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

267

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

268

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

PubMed

This study determined the optimal conditions required to attain maximum metal recovery in the bioleaching process of dewatered metal-plating sludge using Acidithiobacillus ferrooxidans (A. ferrooxidans). Adaptation of this strain was carried up to 1% (w/v) of the sample. Three factors including initial pH, initial Fe(3+) concentration and pulp density were selected as the effective factors and were optimized using a central composite design of response surface methodology. An initial pH of 1, pulp density of 9 g/l and initial Fe(3+) concentration of 1g/l were determined to be optimum values by the statistical models. The highest extractions for Cr and Ni under optimal conditions were 55.6% and 58.2%, respectively. Bioleaching kinetics was investigated using a modified shrinking core model to better understand the mechanism of the leaching reaction. The model predictions indicate that the diffusion step controlled the overall dissolution kinetics and is the rate controlling step. PMID:24971945

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

2014-09-01

269

Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: filtration performance, membrane fouling and cake behavior.  

PubMed

The diatomite dynamic membrane (DDM) was utilized to dewater Chlorella pyrenoidosa of 2 g dry weight/L under continuous-flow mode, whose ultimate algae concentration ranged from 43 g to 22 g dry weight/L of different culture time. The stable flux of DDM could reach 30 L/m(2) h over a 24 h operation time without backwash. Influences of extracellular organic matters (EOM) on filtration behavior and membrane fouling were studied. The DDM was divided into three sub-layers, the slime layer, the algae layer and the diatomite layer from the outside to the inside of the cake layer based on components and morphologies. It was found that EOM caused membrane fouling by accumulating in the slime and algae layers. The DDM intercepted polysaccharides, protein-like substances, humic-like substances and some low-MW organics. Proteins were indicated the major membrane foulants with increased protein/polysaccharide ratio from the slime layer to the diatomite layer as culture time increased. This method could be applied to subsequent treatment of microalgae coupling technology of wastewater treatment or microalgae harvesting for producing biofuel. PMID:24148755

Zhang, Yalei; Zhao, Yangying; Chu, Huaqiang; Zhou, Xuefei; Dong, Bingzhi

2014-01-01

270

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

271

Strategies for Treating and Dewatering Contaminated Soils and Sediments Simultaneously - 13389  

SciTech Connect

MSE Technology Applications, Inc. (MSE) was asked to perform a series of treatability studies by Global Technologies, Inc. (Global) and M{sup 2} Polymer Technologies, Inc. (M{sup 2} Polymer) using Global's metal treatment agent, Molecular Bonding System (MBS) and M{sup 2} Polymer's super-absorbent polymer, Waste Lock 770 (WL-770). The primary objective of the study was to determine if the two products could be used as a one-step treatment process to reduce the leachability of metals and de-water soils and/or sediments simultaneously. Three phases of work were performed during the treatability study. The first phase consisted of generating four bench-scale samples: two treated using only MBS and two treated using only WL- 770, each at variable concentrations. The second phase consisted of generating nine bench-scale samples that were treated using MBS and WL-770 in combination with three different addition techniques. The third phase consisted of generating four intermediate-scale samples that were treated using MBS and WL-770 simultaneously. The soils used in the treatability study were collected at the Mike Mansfield Advanced Technology Center in Butte, Montana. The collected soils were screened at 4 mesh (4.75 millimeters (mm)) to remove the coarse fraction of the soil and spiked with metallic contaminants of lead, cadmium, nickel, mercury, uranium, chromium, and zinc. (authors)

Bickford, Jody; Foote, Martin [MSE Technology Applications, Inc., 200 Technology Way, Butte, MT 59701 (United States)] [MSE Technology Applications, Inc., 200 Technology Way, Butte, MT 59701 (United States)

2013-07-01

272

Ground-water conditions and effects of mine dewatering in Desert Valley, Humboldt and Pershing Counties, northwestern Nevada, 1962-91  

USGS Publications Warehouse

Desert Valley is a 1,200-square-mile, north- trending, structural basin, about 30 miles northwest of Winnemucca, Nevada. Unconsolidated basin-fill deposits exceeding 7,000 feet in thickness constitute the primary ground-water reservoir. Dewatering operations at an open-pit mine began in the Spring of 1985 in the northeast part of Desert Valley. Ground-water withdrawal for mine dewatering in 1991 was greater than three times the estimated average annual recharge from precipitation. The mine discharge water has been allowed to flow to areas west of the mine where it has created an artificial wetlands. This report documents the 1991 hydrologic conditions in Desert Valley and the change in conditions since predevelopment (pre-1962). It also summarizes the results of analyzing the simulated effects of open-pit mine dewatering on a basin-wide scale over time. Water-level declines associated with the dewatering have propagated north and south of the mine, but have been attenuated to the west due to the infiltration beneath the artificial wetlands. Maximum water-level declines beneath the open pits at the mine, as of Spring 1991, are about 300 feet. Changes in the hydrologic conditions since predevelopment are observed predominantly near the dewatering operations and the associated discharge lakes. General ground-water chemistry is essentially unchanged since pre- development. On the basis of a ground-water flow model used to simulate mine dewatering, a new equilibrium may slowly be approached only after 100 years of recovery from the time mine dewatering ceases.

Berger, D. L.

1995-01-01

273

Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 5, Dewatering report. Revised final report  

SciTech Connect

This report provides an update on dewatering activities at the Durango disposal embankment and presents recommendations for the work required to complete the closure of the cell in 1990 (Section 2). In October 1989, test pit investigations were performed and a toe trench was excavated at the eastern slope of the disposal embankment. A description and results of the test pit investigations along with the implications . of the results relative to the over . all dewatering effort are discussed in Sections 3 through 5. Installation and performance of the 17-well dewatering system were previously described in` the ``StatusReport on Dewatering of Disposal Embankment`` issued in September, 1989. Additional studies are still on-going and are described in Section 6. Laboratory analysis continues on samples taken from the test pits. TAC`s characterization of the hydrogeological conditions at the Durango site is also proceeding. Results of these studies will be presented in subsequent reports. Appendices A and B present construction details of the well point system, toe trench and holding pond. Appendix C summarizes the performance-of the 17 pumping wells prior to winter shutdown and provides information on pumping rates, drawdowns, and disposition of the wells. Appendix D outlines the chronology of the dewatering effort to date.

Not Available

1991-12-01

274

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

275

Reed beds: constructed wetlands for municipal wastewater treatment plant sludge dewatering.  

PubMed

Reed beds are an alternative technology wastewater treatment system that mimic the biogeochemical processes inherent in natural wetlands. The purpose of this project was to determine the effectiveness of a reed bed sludge treatment system (RBSTS) in southern New England after a six-year period of operation by examining the concentrations of selected metals in the reed bed sludge biomass and by determining the fate of solids and selected nutrients. Parameters assessed in both the reed bed influent and effluent: total suspended solids, biochemical oxygen demand, nitrate-nitrogen and total phosphorus. In addition, the following metals were studied in the reed bed influent, effluent and Phragmites plant tissue and the sludge core biomass: boron, cadmium, chromium, copper, iron, lead, manganese, molybdenum, nickel, and zinc. The removal efficiencies for sludge dewatering, total suspended solids and biochemical oxygen demand were all over 90%. Nitrate and total phosphorus removal rates were 90% and 80% respectively. Overall metals removal efficient was 87%. Copper was the only metal in the sludge biomass that exceeded the standards set by the Massachusetts Department of Environmental Protection for land disposal of sludge. The highest metal concentrations, for the most part, tended to be in the lower tier of the sludge profile. The exception was boron, which was more concentrated in the middle tier of the sludge profile. The data and results presented in this paper support the notion that reed bed sludge treatment systems and the use of reed beds provide an efficient and cost effective alternative for municipal sludge treatment. PMID:11804125

Begg, J S; Lavigne, R L; Veneman, P L

2001-01-01

276

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

277

Overpressure generation and episodic dewatering in the Delaware basin, western Texas: The dual nature of a fault zone  

NASA Astrophysics Data System (ADS)

This study combines numerical modeling techniques with field data to investigate overpressure development and episodic dewatering processes in the Delaware Basin and the Central Basin Platform (CBP). Low-permeability shales in the eastern Delaware Basin are characterized by elevated pore fluid pressures that are much greater than hydrostatic pressures. Observed geophysical anomalies such as low resistivity, high conductivity, and high seismic transit time are consistent with the presence of fluid-filled, fractured and mechanically weak rocks in the eastern Delaware Basin. Our new geophysical analyses also indicate that the overpressures likely extend further into the shallower western basin in Culberson County near the sulfur mineralization area. The predicted present-day gas window is located within the overpressure zone, suggesting that overpressure may be maintained by active oil-to-gas conversion. A basin hydrology model Basin2 is modified to evaluate the pore pressure increases by oil-gas conversion from the equation of state (EOS) for the CH4-CO2-H2O system. Our modeling shows that source beds in CBP have been rather shallowly buried and did not become thermally mature to generate gas directly. Overpressure and episodic dewatering processes appear to be the most plausible mechanism to move deep-basin hydrocarbons eastward into the CBP and westward into the shallow margin of the Delaware Basin. The model of long-distance fluid migration from the eastern Delaware across the fault zone into the CBP is supported by the geochemical similarities of oils from the two basins. A model that invokes episodic release of overpressured fluids by hydrofracturing processes can simultaneously provide mechanisms for achieving transient overpressure preservation and substantial, episodic fluid movement. The episodic dewatering through hydrofracturing processes thus can better explain the observed overpressure preservation, long-distance fluid migration, and related mineralization and alteration of evaporitic strata in the Permian Basin.

Hansom, J.; Lee, M.; Wolf, L. W.; Kosuwan, T.

2005-05-01

278

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

2009-09-01

279

Study of de-watering from the gelatinous precipitate formed during co-precipitation of Nd-YAG powder  

SciTech Connect

Neodymium doped Yttrium Aluminium Garnet (Nd:YAG) ceramics have been synthesised using coprecipitation technique and high temperature vacuum sintering. Gelatinous like precipitates were obtained when precursors of Nd, Al and Yb-nitrate solutions are co-precipitated using ammonia co-precipitant. De-watering from the gelatinous like precipitates is a big challenge and it possesses difficulty in filtration. Evaporation of water by heating resulted in strong agglomerated powder. Different agents were used to ease the filtration process, which is correlated with the phase in the calcined powder.

Karmakar, Sanjib; Sharma, Rachna; Pathak, S. K.; Gupta, S. M.; Gupta, P. K. [Laser Materials Development and Devices Division Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

2013-02-05

280

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

281

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

282

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

283

Evaluation of solids dewatering for a pilot-scale thiosorbic lime SO/sub 2/ scrubber. Report for September 1985-April 1986  

SciTech Connect

The paper gives results of an evaluation of solids dewatering for a pilot-scale thiosorbic lime SO/sub 2/ scrubber. Pilot-plant data showed that the dissolved magnesium in thiosorbic lime caused deterioration of solids dewatering properties. The slurry settling rate increased when the slurry shear stresses caused by the hold-tank stirrer and recirculation pump were reduced. The application of flocculant also increased the slurry-solids settling rate. Compared with rotary-drum vacuum filtering, better liquid/solids separation occurred with a centrifuge. Other related performance results are also discussed.

Chang, J.C.S.; Brna, T.G.

1987-04-01

284

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal: Second quarterly progress report period ending 31 March 1989  

SciTech Connect

Battelle, in cooperation with the Electric Power Research Institute (EPRI), Ashbrook-Simon-Hartley (ASH), Kaiser Engineers (KE), Lewis Corporation, and Prof. S.H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine and ultrafine coals. The advanced process, called Electroacoustic Dewatering (EAD), capitalizes on the adaptation of synergistic effects of electric and acoustic fields to a commercial belt filter press design that is used in many other applications. The EAD equipment is described. 2 figs.

Not Available

1989-04-18

285

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

SciTech Connect

In the last quarterly report, it was noticed that the baseline dewatering data varied significantly. This abnormality was attributed to the use of house vacuum which varied significantly during the testing. This quarter tests were repeated using a portable vacuum pump which provided a constant vacuum of 25 inches of mercury. Using 30 secs cake drying time and 30 secs cake formation time, the high- and low-porosity ceramic leaf filters provided 21.5% and 18.0% filter cake moistures, respectively. The solids loading on the high- and low-porosity filters were 0.8 Kg/m 2 and 0.44 Kg/m 2 , respectively. Addition of 10 g/t of an anionic flocculant lowered the filter cake moisture from 22.0% to 14.0% using the high-porosity filter, and 18.0% to 13.5% using the low-porosity filter. Addition of 15 g/t of a cationic flocculant lowered filter cake moisture from 18.0% to 16.0% using the low-porosity filter. High-porosity filter did not provide any lowering of filter cake moisture, however, the solids loading increased from 1.5 kg/m 2 to 5.8 kg/m 2 at a flocculant dosage of 25 g/t. This high solids loading indicated thicker filter cake which would retain a high moisture. Among the three surfactants studied, only the non-ionic and the cationic were effective in lowering the filter cake moisture. 0.4 kg/t of a non-ionic surfactant (octyl phenoxy polyethoxy ethanol) lowered filter cake moisture from 19.5% to 16.8%; and 1 kg/t of the cationic surfactant CPCL, lowered the filter cake moisture from 19.0% to 15.8%. Addition of 0.4 kg/t of copper ions or 0.3 kg/t of aluminum ions lowered the filter cake moisture from 20.5% to 17.0%, using the low-porosity filter. The high-porosity filter which showed increase solids loading (thicker filter cakes) did not provide any lowering of the filter cake moisture. Low-porosity filter was found to be more effective in lowering the filter cake moisture than high-porosity ceramic filter. However, high-porosity was more effective in providing higher solids loading than low-porosity filter.

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

1998-10-21

286

Hydrothermal dewatering of brown coal and catalytic hydrothermal gasification of the organic compounds dissolving in the water using a novel Ni\\/carbon catalyst  

Microsoft Academic Search

Brown coals will continue to be important energy resources in the near future, but their high water contents, which sometimes exceed 50wt%, and their low calorific values restrict their utilization. Development of an efficient treatment method for dewatering and upgrading is desired to utilize brown coals on a large scale. Hydrothermal treatment is believed to be a promising treatment method

Hiroyuki Nakagawa; Akio Namba; Marc Böhlmann; Kouichi Miura

2004-01-01

287

Management of karst water resources in mining area: dewatering in mines and demand for water supply in the Dongshan Mine of Taiyuan, Shanxi Province, North China  

Microsoft Academic Search

Coalfields in North China contain six to seven coal seams in the Permo-Carboniferous strata. The coal seams are underlain by the Ordovician limestone. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice, however, has caused water supply shortage in the mining areas. The most effective solution

Qiang Wu; Wanfang Zhou; Duo Li; Zhiqiang Di; Ying Miao

2006-01-01

288

Effect of polyelectrolyte conditioning on the enhanced dewatering of activated sludge by application of an electric field during the expression phase  

Microsoft Academic Search

Activated sludge is known to be poorly dewaterable due to its high surface charge density and the extreme solids compressibility, even after polyelectrolyte conditioning. The application of an electric field during pressure dewatering (PDW) of sludge can enhance the dewaterability by the electroosmosis effect.A comparative study was conducted to investigate the additional effect of an electric field, applied during the

Hans Saveyn; Geert Pauwels; Rik Timmerman; Paul Van der Meeren

2005-01-01

289

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

290

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

291

Chemical sludge conditioning in combination with different conventional and alternative dewatering devices: chamber filter press, decanter and Bucher press.  

PubMed

The Kemicond process for sludge conditioning consists of chemical treatment with sulphuric acid and hydrogen peroxide at a pH-value of approximately 4 followed by a dewatering unit. It is shown that chemical treatment can improve the dewaterability of ferruginous digested sludge. It is concluded that the Fenton process as well as the oxidation of organics and the formation of iron hydroxo complexes are important reaction mechanisms. Furthermore, the organic matter changes through the acidic oxidative process. With the improvement in dewaterability, it is possible to achieve an increase in TS concentration, which affects a reduction of the sludge volume. Cost savings for sludge disposal can amortize the additional investment and operational costs for chemical treatment. PMID:18821238

Schaum, Christian; Cornel, Peter; Faria, Pedro; Recktenwald, Michael; Norrlöw, Olof

2008-11-01

292

Optimized production of a novel bioflocculant M-C11 by Klebsiella sp. and its application in sludge dewatering.  

PubMed

The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source, nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids (m/m). A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl, methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C. The optimum bioflocculating activity was observed as 92.37% for 2.56mL M-C11 and 0.37g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration (SRF) decreased from 11.6×10(12) to 4.7×10(12)m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents, such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity. PMID:25288552

Liu, Jiewei; Ma, Junwei; Liu, Yanzhong; Yang, Ya; Yue, Dongbei; Wang, Hongtao

2014-10-01

293

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

294

Reuse of liquid, dewatered, and composted sewage sludge on agricultural land: effects of long-term application on soil and crop  

Microsoft Academic Search

To evaluate the effects of repeated sewage sludge applications in comparison to mineral fertilisers on a winter wheat–maize–sugar beet rotation, a field experiment on a silty-loam soil, in the eastern Po Valley (Italy), was carried out since 1988. Municipal-industrial wastewater sludge as anaerobically digested, belt filtered (dewatered), and composted with wheat straw, has been applied at 5 and 10Mg DM

Paolo Mantovi; Guido Baldoni; Giovanni Toderi

2005-01-01

295

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

296

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

297

Effects of dilution ratio and Fe(0) dosing on biohydrogen production from dewatered sludge by hydrothermal pretreatment.  

PubMed

Biohydrogen fermentation of dewatered sludge (DS) with sewage at ratios from 4:1 to 1:20 was investigated. Hydrothermal pretreatment of the sludge solution was performed to accelerate the organic release from the solid phase. The maximum hydrogen yield of 26.3 ± 0.5 mL H2/g volatile solid (VS) was obtained at a 1:10 ratio. Although addition of zero valent iron (ZVI) to anaerobic system was not new, the study of dosing it to enhance the biohydrogen yield might be the first attempt. While Fe(0) plate slightly affected the hydrogen yield, Fe(0) powder improved the amount of hydrogen by 16% and shortened the lag time by 36%. The state of bacteria in the reactor added with ZVI powder was changed and the key enzyme activity was improved as well. Correspondingly, the mechanism of ZVI in accelerating the biofermentation process was also proposed. Our research provides a solution for the centralized treatment of DS in a city. PMID:25244137

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

2014-12-01

298

InSAR analysis of aquifer-system response to 20 years of mine-dewatering in the Carlin gold trend, north-central Nevada  

NASA Astrophysics Data System (ADS)

The Carlin trend in north-central Nevada has the second largest gold resources in the world, most of it produced from large open-pit mines. Heavy groundwater dewatering is required at the mines to lower water levels below the depth of mining which can exceed 400-500 m. The resulting water level declines have produced surface deformation (subsidence) that can be detected and modeled with InSAR to characterize the aquifer-system response and to estimate hydraulic parameters in order to test and refine groundwater models. In a series of studies we examined the effects of dewatering at mines operated by Newmont Mining Corporation and Barrick Gold of North America near Battle Mountain and Carlin, Nevada. The Lone Tree mine operated a large-scale dewatering program between 1992-2006 using deep bedrock wells that pumped between 64-92 hm3/yr (52,000-75,000 acre-ft/yr) and lowered bedrock water levels more than 120 m. InSAR analysis of ERS and Envisat data for the 1992-2000 and 2004-2010 periods showed that as much as 50 cm of aquifer-system compaction occurred in bedrock and in alluvial basin deposits with subsidence rates ranging between 3-6 cm/yr. Since dewatering ended in late 2006 and water levels began rising, only 7 cm of aquifer-system recovery (uplift) has occurred as of 2010 suggesting that most of the aquifer-system compaction was likely inelastic, apparently in the pumped fractured bedrock. The InSAR subsidence data differ significantly from the pre-pumping groundwater model which predicted 2.5 m of subsidence for the 1992-2000 period. The results yield bulk storage coefficients in the range of 7 x 10-3 to 5.6 x 10-5 with a most frequent value of 1.0 x 10-3 (Baffoe-Twum, 2007), InSAR-derived hydraulic values that can provide better constraints on specific storage estimates in future groundwater models. The Betze-Post mine has been dewatering continually since late 1989 with maximum pumping rates of greater than 140 hm3/yr (110,000 acre-ft/yr) in the early and late 1990s. This resulted in the lowering of groundwater levels by as much as 500 m in some areas. Analysis of InSAR data covering the 1992-2000 and 2004-2010 time periods suggests a cumulative measured subsidence magnitude of approximately 50 cm. In this case, all of the aquifer-system compaction is occurring in bedrock. Estimates of bulk storage coefficients at Betze-Post are also on the order of approximately 1.0 x 10-3 suggesting that subsidence at both sites is occurring in materials of similar character. Subsidence rates have decreased to near zero since groundwater production was reduced in the early 2000s. Since the early 2000s, subsidence rates resulting from dewatering at the neighboring Leeville mine have been greater than those at Betze-Post. Dewatering at the Turquoise Ridge-Twin Creeks and Gold Quarry mines, adjacent to these two larger mines, has also produced measureable aquifer-system compaction but with lower rates of subsidence. However, detailed hydrologic analyses have not been undertaken at these mines.

Bell, J. W.; Katzenstein, K.

2012-12-01

299

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

300

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

301

The impact of pumped water from a de-watered Magnesian limestone quarry on an adjacent wetland: Thrislington, County Durham, UK.  

PubMed

Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels. PMID:15993994

Mayes, W M; Large, A R G; Younger, P L

2005-12-01

302

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

303

Kinetics of nitrification in a fixed biofilm reactor using dewatered sludge-fly ash composite ceramic particle as a supporting medium.  

PubMed

A mathematical model system was derived to describe the kinetics of ammonium nitrification in a fixed biofilm reactor using dewatered sludge-fly ash composite ceramic particle as a supporting medium. The model incorporates diffusive mass transport and Monod kinetics. The model was solved using a combination of the orthogonal collocation method and Gear's method. A batch test was conducted to observe the nitrification of ammonium-nitrogen ([Formula: see text]-N) and the growth of nitrifying biomass. The compositions of nitrifying bacterial community in the batch kinetic test were analyzed using PCR-DGGE method. The experimental results show that the most staining intensity abundance of bands occurred on day 2.75 with the highest biomass concentration of 46.5 mg/L. Chemostat kinetic tests were performed independently to evaluate the biokinetic parameters used in the model prediction. In the column test, the removal efficiency of [Formula: see text]-N was approximately 96 % while the concentration of suspended nitrifying biomass was approximately 16 mg VSS/L and model-predicted biofilm thickness reached up to 0.21 cm in the steady state. The profiles of denaturing gradient gel electrophoresis (DGGE) of different microbial communities demonstrated that indigenous nitrifying bacteria (Nitrospira and Nitrobacter) existed and were the dominant species in the fixed biofilm process. PMID:25135313

Lee, Mong-Chuan; Lin, Yen-Hui; Yu, Huang-Wei

2014-11-01

304

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

305

Ground-water levels, water quality, and potential effects of toxic-substance spills or cessation of quarry dewatering near a municipal ground-water supply, southeastern Franklin County, Ohio  

USGS Publications Warehouse

A newly completed municipal ground-water supply that produces from a sand and gravel aquifer in southern Franklin County, Ohio, may be susceptible to potential sources of pollution. Among these are spills of toxic substances that could enter recharge areas of the aquifer or be carried by surface drainage and subsequently enter the aquifer by induced infiltration. Ground water of degraded quality also is present in the vicinity of several landfills located upstream from the municipal supply. Local dewatering by quarrying operations has created a ground-water divide which, at present, prevents direct movement of the degraded ground water to the municipal supply. In addition, the dewatering has held water levels at the largest landfills below the base of the landfill. Should the dewatering cease, concern would be raised regarding the rise of water levels at this landfills and transport of contaminants through the aquifer to the Scioto River and subsequently by the river to the well field. From June 1984 through July 1986, the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, investigated the relations among the ground-water supply and potential sources of contamination by means of an observation-well network and a program of measuring water levels and sampling for water quality. Sample collections included those made to determine the baseline levels of organic chemicals and metals, as well as periodic sampling and analysis for common constituents to evaluate any changes taking place in the system. Finally, a steady-state, three-dimensional numerical model was used to determine ground-water flow directions and average ground-water velocities to asses potential effects of toxic-substance spills. The model also was used to simulate changes in the ground-water flow system that could result if part or all of the quarry dewatering ceased. Few of the organic-chemical and metal constituents analyzed for were present at detectable levels. With respect to chemical analysis of water and soil materials reported in earlier studies, no new problem areas were discovered as a result of either the baseline or periodic samplings. Model simulations suggest that, under March 1986 conditions, a toxic-substance spill along the major highways in the northern two-thirds of the study area eventually could discharge into one of the two quarries being dewatered or into the Scioto River. A toxic-substance spill in the southern one-third of the study area ultimately may discharge into the Scioto River, Big Walnut Creek, or possibly into the municipal ground-water supply. Model simulations also indicate that concentrated landfill leachate probably would not reach the municipal ground-water supply under current or well-field pumping conditions if dewatering ceased at either or both of the quarries.

Sedam, A. C.; Eberts, S. M.; Bair, E. S.

1989-01-01

306

Bench-scale testing of DOE/PETC`s GranuFlow Process for fine coal dewatering and handling. 1: Results using a high-gravity solid-bowl centrifuge  

SciTech Connect

Most advanced fine-coal cleaning processes involve the use of water. Utility companies are concerned not only with the lower Btu content of the resulting wet, cleaned coal, but more importantly with its handleability problems. Solutions to these problems would enhance the utilization of fine-coal cleaning processes in the utility industry. This paper describes testing of the GranuFlow Process, developed and patented by the Pittsburgh Energy Technology Center (PETC) of the US Department of Energy, using a high-gravity solid bowl centrifuge for dewatering and reconstitution of fine-cleaned-coal slurry at 300 lb per hour in PETC`s Coal Preparation Process Research Facility. Fine-cleaned-coal slurry was treated with a bitumen emulsion before dewatering in a high-gravity solid-bowl centrifuge. The treated products appeared to be dry and in a free-flowing granular form, while the untreated products were wet, lumpy, sticky, and difficult to handle. Specifically, test results indicated that the moisture content, handleability, and dust reduction of the dewatered coal product improved as the addition of emulsion increased from 2% to 8%. The improvement in handleability was most visible for the 200 mesh (75 micron) x 0 coal, when compared with 150 mesh (106 micron) x 0, 65 mesh (212 micron) x 0 or 28 mesh (600 micron) x 0 coals. Test results also showed that the moisture content was dramatically reduced (26--37% reduction) for the four different sizes of coals at 6 or 8% emulsion addition. Because of the moisture reduction and the granular form of the product, the freezing problem was also alleviated.

Wen, W.W.; Killmeyer, R.P.; Lowman, R.H.; Elstrodt, R. [Dept. of Energy, Pittsburgh, PA (United States). Pittsburgh Energy Technology Center

1995-12-31

307

Revealing the microbial community structure of clogging materials in dewatering wells differing in physico-chemical parameters in an open-cast mining area.  

PubMed

Iron rich deposits cause clogging the pumps and pipes of dewatering wells in open-cast mines, interfering with their function; however, little is known about either the microbial community structure or their potential role in the formation of these deposits. The microbial diversity and abundance of iron-oxidizing and -reducing bacteria were compared in pipe deposit samples with different levels of encrustation from 16 wells at three lignite mining sites. The groundwater varied in pH values from slightly acidic (4.5) to neutral (7.3), Fe(II) concentrations from 0.48 to 7.55 mM, oxygen content from 1.8 to 5.8 mg L(-1), and dissolved organic carbon (DOC) from 1.43 to 12.59 mg L(-1). There were high numbers of bacterial 16S rRNA gene copies in deposits, up to 2.5 × 10(10) copies g(-1) wet weight. Pyrosequencing analysis of bacterial 16S rRNA genes revealed that Proteobacteria was the most abundant phylum (63.3% of the total reads on average), followed by Actinobacteria (10.2%) and Chloroflexi (6.4%). Gallionella-related sequences dominated the bacterial community of pipe deposits and accounted for 48% of total sequence reads. Pipe deposits with amorphous ferrihydrite and schwertmannite mostly contained Gallionella (up to 1.51 × 10(10) 16S rRNA gene copies g(-1) wet weight), while more crystalline deposits showed a higher bacterial diversity. Surprisingly, the abundance of Gallionella was not correlated with groundwater pH, oxygen, or DOC content. Sideroxydans-related 16S rRNA gene copy numbers were one order of magnitude less than Gallionella, followed by acidophilic Ferrovum-related groups. Iron reducing bacteria were detected at rather low abundance, as was expected given the low iron reduction potential, although they could be stimulated by lactate amendment. The overall high abundance of Gallionella suggests that microbes may make major contributions to pipe deposit formation irrespective of the water geochemistry. Their iron oxidation activity might initiate the formation of amorphous iron oxides, potentially providing niches for other microorganisms later after crystallization, and leading to higher bacterial diversity along with deposit accumulation in later stages of clogging. PMID:25010562

Wang, Juanjuan; Sickinger, Maren; Ciobota, Valerian; Herrmann, Martina; Rasch, Helfried; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

2014-10-15

308

Floc Property Effects on Sludge Dewatering Characteristics.  

National Technical Information Service (NTIS)

The technical and economic problems associated with sludge handling and disposal have increased in recent years because of (1) the introduction of more stringent water and air pollution regulations and (2) the development of regulations that stipulate the...

W. R. Knocke, D. L. Wakeland

1982-01-01

309

Application of amphoteric polyelectrolytes for sludge dewatering  

Microsoft Academic Search

Conventional sludge conditioning with polymer flocculants usually involves the addition of either a cationic polymer or a combination of a cationic and an anionic polymer. On the other hand, a combination of a metal coagulant and an amphoteric polymer was found to produce large, mechanically strong flocs. On the basis of this observation and by use of the colloid titration

Y. Watanabe; K. Kubo; S. Sato

1999-01-01

310

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

311

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

312

Ternary expression stage in biological sludge dewatering  

Microsoft Academic Search

The expression characteristics of original and freeze\\/thaw conditioned waste activated sludges were experimentally evaluated. Results in this study indicate that the first two stages of expression (primary and secondary consolidation) are similar to those of a particulate system, on which the model analysis by Shirato et al. (1974) is applicable. In the final phase of the expression of biological sludge,

I. L. Chang; D. J. Lee

1998-01-01

313

In focus: Dewatering. [Use of ceramic filters for dewatering mine slurries as wastes  

SciTech Connect

A process filter whose operation is based on a simple hydrostatics phenomenon that is taught in school physics classes is able to improve the productivity of process plant, reduce equipment space and complexity, improve the plant environment and reduce overall processing costs. The author gives an overview of his company's capillary filtration technology and Engineering Editor Nick Horton describes how it works, with information and diagrams courtesy of Outokumpu Mintec.

Rantala, P.

1994-09-01

314

AUTOMATION OF SLUDGE PROCESSING: CONDITIONING, DEWATERING, AND INCINERATION  

EPA Science Inventory

The study developed and tested automated control strategies for municipal wastewater sludge processing. The strategies consisted of chemical conditioning vacuum filtration and incineration. The project was conducted at the St. Paul, Minnesota Metropolitan Waste Control Commission...

315

DRYING AND DEWATERING R&D IN JAPAN  

Microsoft Academic Search

Presently, it has become an urgent and important concern worldwide to reduce the volume of waste and rationally use the waste for electric power generation. Sludge is a dominant part in the family of wastes. Drying of sludge, not only for volume reduction but also for further utilization, is becoming an essential and integral process. On the other hand, as

Masanobu Hasatani; Noriyuki Kobayashi; Zhanyong Li

2001-01-01

316

A Novel Flocculant for Enhanced Dewatering of Oil Sands Tailings.  

E-print Network

??A cationic thermal sensitive polymer, poly[N-isopropylacrylamide-co-N-[3-(Dimethylamino)propyl]methacrylamide] (CP) of different molar ratios, known as CP05 and CP10 was synthesized in-house. By doping aluminum hydroxide (Al(OH)3) colloids… (more)

Chan, Margo Chi Wing

2011-01-01

317

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

318

Extreme efficiency of mud volcanism in dewatering accretionary prisms  

Microsoft Academic Search

Drilling results from two mud volcanoes on the Mediterranean Ridge accretionary complex as well as bottom sampling and the wealth of geophysical data acquired recently have provided fundamental knowledge of the 3D geometry of mud extrusions. Mud volcanism is generally related to buoyancy (density inversion), and is triggered by the collision of the African and Eurasian blocks, forcing undercompacted clayey

Achim Kopf; Dirk Klaeschen; Jean Mascle

2001-01-01

319

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

320

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

321

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...

322

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...

323

Effect of osmotic dewatering on apple tissue structure  

Microsoft Academic Search

Apple cubes were subjected to osmotic dehydration in 61.5% sucrose and changes in tissue structure were examined in light microscope. Fixed and embedded in raisin 3 ?m thick slices were analysed and indices characterising apple tissue structure were calculated with computer image analysis. It was found that osmotic dehydration affects size and shape of cells, and in consequence changes shape

Piotr P. Lewicki; Renata Porzecka-Pawlak

2005-01-01

324

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

325

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

Microsoft Academic Search

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

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

1985-01-01

326

Use of a Computer Model To Design Optimal Wellfields for Dewatering Coal Seams for Methane Production  

Microsoft Academic Search

A model is presented for optimizing the number and locations of wells for various hydrologic and reservoir conditions. It can handle confined or unconfined aquifers, leaky or non-leaky aquifers, isotropic or anisotropic permeabilities, existing wells at fixed or model-determined optimal flow rates, complex boundaries, and specified regions to be excluded from possible well location sites for environmental or other reasons.

A. C. Bumb; C. R. McKee

1984-01-01

327

Reed beds: constructed wetlands for municipal wastewater treatment plant sludge dewatering  

Microsoft Academic Search

Reed beds are an alternative technology wastewater treatment system that mimic the biogeochemical processes inherent in natural wetlands. The purpose of this project was to determine the effectiveness of a reed bed sludge treatment system (RBSTS) in southern New England after a six-year period of operation by examining the concentrations of selected metals in the reed bed sludge biomass and

J. S. Begg; R. L. Lavigne; P. L. M. Veneman

328

Bioaccumulation of triclosan and triclocarban in plants grown in soils amended with municipal dewatered biosolids.  

PubMed

Biosolids generally contain the microbiocidal agents triclosan (TCS) and triclocarban (TCC) that are persistent during wastewater treatment and sorp to organic material. The present study investigated the concentration of TCS in tissues of radish, carrot, and soybean grown in potted soil amended with biosolids. Highest mean concentrations of TCS in radish, carrot, and soybean root tissue midway through the life cycle were 24.8?ng/g, 49.8?ng/g, and 48.1?ng/g dry weight, respectively; by the conclusion of the test, however, concentrations had declined to 2.1?ng/g, 5.5?ng/g, and 8.4?ng/g dry weight, respectively. Highest mean concentrations of TCS in radish and carrot shoot tissue were 33.7 and 18.3?ng/g dry weight at days 19 and 45, respectively, but had declined to 13.7?ng/g and 5.5?ng/g dry weight at days 34 and 69, respectively. Concentration of TCS in all samples of soybean seeds was below method detection limit (i.e., 2.8?ng/g dry wt). The present study also examined the concentration of TCS and TCC in edible portions of green pepper, carrot, cucumber, tomato, radish, and lettuce plants grown in a field amended with biosolids. Triclosan was detected only in cucumber and radish up to 5.2?ng/g dry weight. Triclocarban was detected in carrot, green pepper, tomato, and cucumber up to 5.7?ng/g dry weight. On the basis of the present study and other studies, we estimate that vegetable consumption represents less than 0.5% of the acceptable daily intake of TCS and TCC. These results demonstrate that, if best management practices for land application of biosolids in Ontario are followed, the concentration of TCS and TCC in edible portions of plants represents a negligible exposure pathway to humans. PMID:24375516

Prosser, Ryan S; Lissemore, Linda; Topp, Edward; Sibley, Paul K

2014-05-01

329

Flocculation and filtration dewatering of coal slurries aided by a hydrophobic polymeric flocculant  

SciTech Connect

This study investigated the adsorption behavior of a totally hydrophobic polymer, FR-7A, and its role in the flocculation and filtration of fine coal slurries. Adsorption of FR-7A on coal, pyrite, and shale minerals revealed that: (a) FR-7A had a higher adsorption affinity to coal and pyrite than that on shale; (b) an acidic slurry condition favored unselective adsorption of FR-7A on coal minerals, leading to improved total flocculation and filtration of fine coal slurries, while alkaline pH and the presence of SMP favored selective adsorption and flocculation of coal from associated minerals in the slurry; and (c) FR-7A aided the flocculation of coal slurries and improved the moisture removal by filtration from 42.4 to 37%.

Attia, Y.A.; Yu, S. (Ohio State Univ., Columbus (USA))

1991-01-01

330

Dewatering of the open pits at Letlhakane and Orapa diamond mines, Botswana  

Microsoft Academic Search

Kimberlite pipes are mined open cast for diamonds at Orapa and Letlhakane in Botswana. The kimberlites are very low permeability\\u000a even when weathered but are saturated due to high ground water levels. The country rocks of basalts overlying sandstones contain\\u000a significant quantities of water at various piezometric pressures.\\u000a \\u000a A very large kimberlite pipe is mined at Orapa and 2 small

R J Connelly; J Gibson

1985-01-01

331

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

E-print Network

Laurentide ice sheet till has implications for both the motion of the southern Laurentide ice lobes (e in those areas with few exposures such as the southern margin of the Laurentide ice sheet (Mickelson

Carlson, Anders

332

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

333

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

334

An experimental investigation of microalgal dewatering efficiency of a belt filter system  

E-print Network

in the highest clarification efficiency. ……………………………………......….60 Figure B.1 Aluminum channel …………………………….…………………………………..68 Figure B.2 Top rail section 3 back …………………………………………………………….69 Figure B.3 Top rail section 3 front …………………………………………………………….70 Figure B.4... charge causing intracellular repulsion forces. In order to neutralize the charge, cationic flocculants are added to microalgal suspension to facilitate aggregation. An ideal flocculant would be non-toxic, inexpensive and effective in low concentration...

Sandip, Anjali

2014-05-31

335

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

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 The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation processes, is possibly in error. This seems to be a very real possibility for low rank coals, i.e. lignites. To explore this hypothesis further requires an examination of the basic phenomena governing the swelling of coals in good solvents. This is the focus of the first part of this project. The possibility that coal holds a significant portion of its moisture by solvent swelling mechanisms leads to an interesting technical issue. It is well known that simple drying of low rank coals is ineffective because the process is reversible, to a significant degree. Pyrolytic treatments of the coals in oil, steam or liquid water itself. Pyrolytically remove oxygen groups, which are assumed to be those that hold water most strongly by hydrogen bonding. The treatments have been designed to minimize tar formation and decrepitation of the particles, both highly undesirable. In relation to the present new hypothesis concerning water retention, it is likely that a sound approach to permanent drying would involve highly crosslinking the coal at mild drying conditions. The crosslinked coal could not swell sufficiently to hold much water. It is identifying processes to achieve this goal, that constitute the objective of the second phase of this work.

Suuberg, E.M.

1992-12-18

336

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

Microsoft Academic Search

This project is concerned with the ability of coal to hold moisture is it a manifestation of the well-known ability of coal to swell, when exposed to good solvents The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation processes, is possibly in error. To explore this hypothesis further requires

Suuberg

1991-01-01

337

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

Microsoft Academic Search

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 The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation

Suuberg

1992-01-01

338

Propagule banks: Potential contribution to restoration of an impounded and dewatered riparian ecosystem  

Microsoft Academic Search

The Agua Fria River in Arizona’s Sonoran Desert was impounded and diverted more than 70 years ago. Immediately below New Waddell\\u000a dam there are semi-permanent pools, but water has been released into the channel only during rare wet years. To determine\\u000a whether a propagule bank exists below the dam, and whether it could contribute to the revegetation of the Agua

Jere A. Boudell; Juliet C. Stromberg

2008-01-01

339

PROPAGULE BANKS: POTENTIAL CONTRIBUTION TO RESTORATION OF AN IMPOUNDED AND DEWATERED RIPARIAN ECOSYSTEM  

Microsoft Academic Search

The Agua Fria River in Arizona's Sonoran Desert was impounded and diverted more than 70 years ago. Immediately below New Waddell dam there are semi-permanent pools, but water has been released into the channel only during rare wet years. To determine whether a propagule bank exists below the dam, and whether it could contribute to the revegetation of the Agua

Jere A. Boudell; Juliet C. Stromberg

2008-01-01

340

Perched brine plumes above salt domes and dewatering of geopressured sediments  

NASA Astrophysics Data System (ADS)

Previous studies have shown that there is a brine plume with more than 160 g l -1 total dissolved solids (TDS) in the subsurface, perched above Welsh Salt Dome in South Louisiana. The occurrence of this plume has been postulated to be due to the expulsion of geopressured fluids up a fault on the flank of Welsh Dome. The process that resulted in formation of the anomalous brine plume near Welsh Dome is of importance because hydrocarbon production is approximately coincident with the brine plume in map plan, although in cross-sections, the brine plume actually occurs a few hundred meters above hydrocarbon production zones. Using a variable density groundwater flow model, SUTRA, we tested the hypothesis that a pulse of fluid flow up the fault could result in brine formation near the top of the dome. When the permeability of the geopressured zone was very low in our simulations, brine formation in the hydropressured zone occurred entirely by brine-density flow and flow was downward along the fault flanking the dome. Above a certain threshold permeability for the geopressured zone, between 10 -7 darcy and 10 -5 darcy in the vertical direction, geopressured fluids were forced up the fault and brine formation occurred above the dome rather than on the flank. Brines can theoretically form above salt domes in very short geologic times (10 -1 Ma) by expulsion of waters from the geopressured zone below, but the fluid effluxes required are gigantic and appear to be unsustainable over large time intervals such as 10 Ma.

Ranganathan, V.; Hanor, J. S.

1989-09-01

341

ElectroAcoustic Dewatering (EAD) a Novel Approach for Food Processing, and Recovery  

Microsoft Academic Search

Separation of liquids from fine particle suspensions plays an important role in many industrial processes. In the past few years a number of technologies have been developed for the separation of slurries with coarse particle suspensions and intermediate particle sizes. However, separation of fine particles from their suspensions can be difficult and prohibitively costly.Battelle has developed a solid\\/liquid separation technology

H. S. Muralidhara; S. P. Chauhan; N. Senapati; R. Beard; B. Jirjis; B. C. Kim

1988-01-01

342

A method for detecting dewatering effects of underground mining activities on surface wetlands  

SciTech Connect

In 1996 US Energy/Kennecott Uranium Company initiated a large-scale, long-term monitoring program to document whether or not proposed uranium mining activities under Green Mountain in Central Wyoming would cause a groundwater draw-down resulting in changes in the existing riparian/wetland habitats. The monitoring program consisted of establishing 12 study drainages on Green Mountain and six control drainages on an adjacent but hydrologically isolated mountain not scheduled for mining. Baseline data were collected in 1996 and 1997 prior to the commencement of mining. For each drainage, breeding bird densities (birds/km) and richness (species/km), winter wild ungulate fecal pellet group densities (groups/km), small mammal densities (captures/trap night), and density and species composition of aquatic macro invertebrates were measured along permanent, marked transects within each riparian zone. In order to characterize the baseline vegetation and isolate the effects of livestock grazing, species composition, percent cover, production, and type boundary delineation of riparian vegetation were quantified within adjacent fenced and unfenced half-acre sample sites within each drainage. Baseline photographs were taken at permanent marked points from fixed angles at each of the sample sites. Piezometer holes were drilled at each monitoring site for measuring potential changes in ground water levels over time. If, during mining, water levels are found to drop significantly from baseline, a new study of wildlife and vegetative parameters would be conducted to determine whether or not significant decreases in wetland function or changes from baseline characteristics have occurred.

Hayden-Wing, L.D.; Baldwin, J.R.; Webber, K.; Winstead, J.B.

1999-07-01

343

PROCESSING OF FRESH, PARTIALLY DEWATERED HERBS WITH NEAR-CRITICAL FLUIDS  

Microsoft Academic Search

The extraction of essential oils and oleoresins from dry herbs and spices using supercritical and liquid CO2 is practised on an industrial scale. Extraction is only economically and technically feasible for herbs that have relatively high value essential oils that are not degraded by drying of the freshly harvested herb. The extraction of essential oils from fresh herbs is not

O. J. Catchpole; B. M. Smallfield; P. J. Dyer; J. B. Grey; C. McNamara; N. B. Perry; N. E. Durling

344

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.

TEDESCHI AR

2008-01-23

345

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

346

ACOUSTIC DEWATERING AND DRYING (LOW AND HIGH FREQUENCY): STATE OF THE ART REVIEW  

Microsoft Academic Search

The potential of ultrasonic energy to dry heat-sensitive materials was proven by studies conducted a number of years ago. Ultrasonic irradiation improved the rates of drying and the temperatures seldom exceeded 1 C above ambient. Recent developments in energy related areas of technology have caused a new search for more economical methods of drying.This paper reviews both past and present

H. S. Muralidhara; D. Ensminger; A. Putnam

1985-01-01

347

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

348

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

349

Syneresis cracks: subaqueous shrinkage in argillaceous sediments caused by earthquake-induced dewatering  

Microsoft Academic Search

Syneresis cracks, often confused with subaerial desiccation phenomena, are traditionally ascribed to subaqueous shrinkage whereby salinity changes caused deflocculation of clay. This and other previously proposed mechanisms fail to account for their occurrence in low-energy, typically non-evaporitic facies, stratigraphically sporadic distribution, intrastratal formation under shallow burial depths, variation in morphology, degree of contraction, generation of sedimentary dikelets as crack fills,

Brian R. Pratt

1998-01-01

350

Seep faunas and other indicators of methane?rich dewatering on New Zealand convergent margins  

Microsoft Academic Search

Fluid seeps, many marked by rich, distinctive, chemosynthetic faunas living independently of the Earth's photosynthesis?based food chain, are indicators of sedimentological and tectonic processes at convergent margins. Thirteen seep sites, seven marked by distinctive faunas and others marked by carbonate chimneys, carbonate crusts, or plumes of low?density fluids on sounder records, are reported from the vicinity of the convergent plate

Keith B. Lewis; Bruce A. Marshall

1996-01-01

351

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

352

Tracing the Hydrologic Connection between Turquoise Lake and Local Mine Dewatering Tunnels with Dissolved Sulfur Hexafluoride (SF6)  

Microsoft Academic Search

To determine the potential hydraulic connection of Turquoise Lake to water movement in and through the mines and related fractures of the Sugar Loaf mining district, 166 moles of the gas sulfur hexafluoride (SF6) were injected into Turquoise Lake in July 2003. High lake levels were long suspected for contributing to the growth and appearance of wetlands developed at the

Josiah N. Engblom; William E. Sanford; John D. Stednick

2004-01-01

353

Remnants of Melt Pools and Melt Films Associated with Dewatering of Nominally Anhydrous Minerals in Lower Crustal Granite  

NASA Astrophysics Data System (ADS)

Water locked in structural sites and in fluid inclusions in nominally anhydrous minerals in lower crustal granitoids may act as a flux for partial melting of these source rocks. Microtextural study of the 2.6 Ga Stevenson granite of the Athabasca Granulite Terrane of northern Saskatchewan shows that increasing intensity of deformation of the granite correlates with migration of water from within crystals to grain boundaries. Dark, ultrafine-grained, water-richer matrix material consisting of quartz, plagioclase, alkali feldspar and fine iron oxides are interpreted to be former melt films that resulted, at least in part, from fluxing by NAM-derived water. Melt films on the grain boundaries of plagioclase, potassium feldspar and quartz are approximately 20 microns wide. Melt pools are up to 100+ microns in diameter. Water in nominally anhydrous minerals has the potential to lower the solidus significantly enough to initiate partial melting in lower crustal granitoids at high ambient temperatures. 3000 ppm water in minerals that make up large volumes of crustal rocks (alkali feldspar, plagioclase feldspar, quartz) would lower the dry solidus of granite by 273oC at 1 GPa, for initiation of partial melting. Generation of small volumes of partial melt on grain boundaries may lead to further rock weakening and localization of further deformation.

Seaman, S. J.; Williams, M. L.

2013-12-01

354

Waste paper and clinoptilolite as a bulking material with dewatered anaerobically stabilized primary sewage sludge (DASPSS) for compost production  

Microsoft Academic Search

Environmental problems associated with sewage sludge disposal have prompted strict legislative actions over the past few years. At the same time, the upgrading and expansion of wastewater treatment plants have greatly increased the volume of sludge generated. The major limitation of land application of sewage sludge compost is the potential for high heavy metal content in relation to the metal

Antonis A Zorpas; Dimitris Arapoglou; Karlis Panagiotis

2003-01-01

355

Pharmaceuticals, hormones, anthropogenic waste indicators, and total estrogenicity in liquid and solid samples from municipal sludge stabilization and dewatering  

USGS Publications Warehouse

The ubiquitous presence of pharmaceuticals and other emerging contaminants, or trace organic compounds, in surface water has resulted in research and monitoring efforts to identify contaminant sources to surface waters and to better understand loadings from these sources. Wastewater treatment plant discharges have been identified as an important point source of trace organic compounds to surface water and understanding the transport and transformation of these contaminants through wastewater treatment process is essential to controlling their introduction to receiving waters.

Furlong, Edward T.; Gray, James L.; Quanrud, David M.; Teske, Sondra S.; Werner, Stephen L.; Esposito, Kathleen; Marine, Jeremy; Ela, Wendell P.; Zaugg, Steven D.; Phillips, Patrick J.; Stinson, Beverley

2012-01-01

356

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...

357

Water-Level Fluctuations in Mediterranean Reservoirs: Setting a Dewatering Threshold as a Management Tool to Improve Water Quality  

Microsoft Academic Search

Water-level fluctuations, often linked to seasonal climatic trends, are a natural phenomenon which occur in almost all aquatic ecosystems. In some climatic regions, as the Mediterranean one, they are particularly wide due to the occurrence of two well separated periods: the rainy winter and the almost completely dry summer. Precipitation is concentrated in the first period, whereas in the second

Luigi Naselli-Flores; Rossella Barone

2005-01-01

358

Investigation of the effect of polymer structure type on flocculation, rheology and dewatering behaviour of kaolinite dispersions  

Microsoft Academic Search

The influence of an anionic polyacrylamide–acrylate copolymer (PAM) and a nonionic polyethylene oxide (PEO) polymer on the surface chemistry, shear yield stress, settling rates and consolidation behaviour of kaolinite dispersions has been investigated at pH 7.5. The magnitude of the particle zeta potential decreased with increasing flocculant concentration for both flocculants but was much greater for PEO, due to an

Patience Mpofu; Jonas Addai-Mensah; John Ralston

2003-01-01

359

A comparison of instrumental dewatering methods for the separation and concentration of suspended sediment for subsequent trace element analysis  

USGS Publications Warehouse

The continuous-flow centrifuges can process whole water at an influent feed rate of 41 per minute; however, when suspended sediment concentrations are low (<30 mg l-1), when small volumes of whole water are to be processed (30 to 401), or when suspended sediment mean grain size is very fine (<10 ??m), influent feed rates of 21 per minute may be more efficient. Tangential-flow filtration can be used to process samples at the rate of 11 per minute. -from Authors

Horowitz, A. J.; Elrick, K. A.; Hooper, R. C.

1989-01-01

360

40 CFR 141.76 - Recycle provisions.  

...thickener supernatant, or liquids from dewatering processes must meet the requirements...thickener supernatant, or liquids from dewatering processes. This notification must...thickener supernatant, and liquids from dewatering processes), the hydraulic...

2014-07-01

361

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2012 CFR

...thickener supernatant, or liquids from dewatering processes must meet the requirements...thickener supernatant, or liquids from dewatering processes. This notification must...thickener supernatant, and liquids from dewatering processes), the hydraulic...

2012-07-01

362

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).  

Code of Federal Regulations, 2013 CFR

...measures must be employed as specified by the permitting authority. (c) Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, are prohibited unless managed by...

2013-07-01

363

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2011 CFR

...thickener supernatant, or liquids from dewatering processes must meet the requirements...thickener supernatant, or liquids from dewatering processes. This notification must...thickener supernatant, and liquids from dewatering processes), the hydraulic...

2011-07-01

364

77 FR 12497 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste Exclusion  

Federal Register 2010, 2011, 2012, 2013

...tanks through oil recovery and dewatering. The sludge is not accumulated...filter press for oil recovery and dewatering. Recovered oil is reinserted into the refining process and water from dewatering is routed to the Refinery's...

2012-03-01

365

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

Code of Federal Regulations, 2013 CFR

...Drilling Fluids, Drill Cuttings, and Dewatering Effluent: 1 (A) All coastal areas...drilling fluids, drill cuttings, and dewatering effluent SPP Toxicity Minimum 96-hour... Non-aqueous drilling fluids and dewatering effluent No discharge. Drill...

2013-07-01

366

FRUIT CANNERY WASTE ACTIVATED SLUDGE AS A CATTLE FEED INGREDIENT  

EPA Science Inventory

The feasibility of sludge disposal, from a fruit processing waste activated sludge treatment system, by dewatering and using the dewatered biological sludge solids as cattle feed was evaluated by Snokist Growers at Yakima, Washington. Dewatering of the biological sludge utilizing...

367

75 FR 5564 - Notice of a Project Waiver of Section 1605 (Buy American Requirement) of the American Recovery...  

Federal Register 2010, 2011, 2012, 2013

...a foreign manufactured rotary sludge dewatering press. This is a project specific waiver...determined that a rotary press sludge dewatering unit, manufactured by Fournier Industries...purchase of a 6 channel rotary press sludge dewatering unit, manufactured by Fournier...

2010-02-03

368

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

Code of Federal Regulations, 2013 CFR

...Fluids and Drill Cuttings and Dewatering Effluent: 1 All facilities...fluids, drill cuttings, and dewatering effluent Free Oil No discharge...Non-aqueous drilling fluids and dewatering effluent No discharge....

2013-07-01

369

75 FR 6389 - Notice of a Regional Project Waiver of Section 1605 (Buy American) of the American Recovery and...  

Federal Register 2010, 2011, 2012, 2013

...of foreign manufactured rotary sludge dewatering presses. This is a project specific...two 6-channel rotary press sludge dewatering units, manufactured by Fournier Industries...two, six channel rotary press sludge dewatering units, manufactured by Fournier...

2010-02-09

370

76 FR 76677 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Proposed Exclusion  

Federal Register 2010, 2011, 2012, 2013

...tanks through oil recovery and dewatering. The sludge in the storm water...filter press for oil recovery and dewatering. Recovered oil is reinserted into the refining process and water from dewatering is routed to the Refinery's...

2011-12-08

371

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

Code of Federal Regulations, 2012 CFR

...Fluids and Drill Cuttings and Dewatering Effluent: 1 All facilities...fluids, drill cuttings, and dewatering effluent Free Oil No discharge...Non-aqueous drilling fluids and dewatering effluent No discharge....

2012-07-01

372

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2010 CFR

...thickener supernatant, or liquids from dewatering processes must meet the requirements...thickener supernatant, or liquids from dewatering processes. This notification must...thickener supernatant, and liquids from dewatering processes), the hydraulic...

2010-07-01

373

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).  

Code of Federal Regulations, 2011 CFR

...measures must be employed as specified by the permitting authority. (c) Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, are prohibited unless managed by...

2011-07-01

374

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).  

Code of Federal Regulations, 2012 CFR

...measures must be employed as specified by the permitting authority. (c) Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, are prohibited unless managed by...

2012-07-01

375

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2013 CFR

...thickener supernatant, or liquids from dewatering processes must meet the requirements...thickener supernatant, or liquids from dewatering processes. This notification must...thickener supernatant, and liquids from dewatering processes), the hydraulic...

2013-07-01

376

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

Code of Federal Regulations, 2012 CFR

...Drilling Fluids, Drill Cuttings, and Dewatering Effluent: 1 (A) All coastal areas...drilling fluids, drill cuttings, and dewatering effluent SPP Toxicity Minimum 96-hour... Non-aqueous drilling fluids and dewatering effluent No discharge. Drill...

2012-07-01

377

Visualizing "Fuzzy" Construction Materials Using VITASCOPE's ParticleWorks Add-On Vineet R. Kamat, S.M.ASCE*  

E-print Network

that involve such fuzzy materials include placing concrete, dumping dirt, shotcreting, sandblasting, dewatering, dumping dirt, shotcreting, sandblasting, dewatering, water distribution, and inserting slurry. We

Kamat, Vineet R.

378

School of Chemical Technology 1 (1) http://chem.aalto.fi/fi/  

E-print Network

) as additive in complex suspensions: influence on rheology and dewatering Contents of the dissertation One utilisation of MNFC will affect rheological measurement complexity, processability and dewatering behaviour

Kaski, Samuel

379

College of Engineering Summer Research Experience for Undergraduates Program  

E-print Network

on the characteristics of digestion product, such as dewatering rates and pathogen inactivation, remains unknown, volatile fatty acids, dewatering rates, and enumeration of pathogen indicating organisms. The student

Mountziaris, T. J.

380

Mascle, J., Lohmann, G.P., and Moullade, M. (Eds.), 1998 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 159  

E-print Network

, water-escape structures, presumably triggered by earthquakes, and to dewatering cleavage, itself a consequence of dewatering processes. Synsedimentary listric normal faults have recorded collapses, differen

381

BidOpportunity Bid Opportunity  

E-print Network

, structural and rebar steel, dewatering, water proofing, and sub-surface preparation. The subcontracting with successful track records of completing demolition, dewatering, site work, concrete, pile driving, sheeting

Qian, Ning

382

ESTABoues, a decision tool to assess greenhouse gases of sewage sludge treatment and di  

E-print Network

digestion, aerobic digestion, dewatering, al composting, drying) and sludge disposal route (land application (thickening, dewatering, land spreading...), each gas (dioxide carbon, methane and nitrous oxide) and each

Paris-Sud XI, Université de

383

NORTH-SOUTH VARIABILITY IN THE HISTORY OF DEFORMATION AND FLUID VENTING ACROSS HYDRATE RIDGE, CASCADIA MARGIN  

E-print Network

of sediment compaction, dewatering, and deformation than the younger slope basin strata preserved at SHR prompted investigations of seafloor fluid flow and the dewatering processes associated with accretionary

Goldfinger, Chris

384

REMEDIATION OF HIGH WATER CONTENT GEOMATERIALS: A REVIEW OF GEOTEXTILE FILTER PERFORMANCE  

E-print Network

and dewatering is becoming increasingly popular. Geotextiles commonly used in these projects are expected only be accomplished after a dewatering procedure is completed. Dewatering is an important step strengths (Pilarczyk 2000, Moo-Young et al. 2002). One of the traditional methods of dewatering is exposing

Aydilek, Ahmet

385

Sludge drying reed beds: a full and pilot-scales study for activated sludge treatment  

E-print Network

.troesch@cemagref.fr, dirk.esser@sint.fr Abstract Sludge drying reed beds have been used for dewatering and mineralization the influence of the sludge loading rate, the sludge quality and the loading frequency on the dewatering, dewatering, rheology characteristics INTRODUCTION Sludge drying reed beds (SDRB) for WWTP sludge dewatering

Paris-Sud XI, Université de

386

Early tectonic dewatering and brecciation on the overturned sequence at Marble Bar, Pilbara Craton, Western Australia: dome-related or not?  

Microsoft Academic Search

Cataclastic breccias and hydrothermal fault arrays of likely c. 3400 Ma timing are well developed and exceptionally well exposed in the Marble Bar Chert Member of the Pilbara Craton. Brecciation involved centimetre- to metre-scale clast transport distances, in breccia zones up to 5 m wide, cutting the c. 60 m thick chert in a series of right-lateral fault zones. Our

N. H. S Oliver; P. A Cawood

2001-01-01

387

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 June--31 August, 1992  

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? The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation processes, is possibly in error. This seems to be a very real possibility for low rank coals- i.e. lignites. To explore this hypothesis further requires an examination of the basic phenomena governing the swelling of coals in good solvents. This is the focus of the first part of this project. The possibility that coal holds a significant portion of its moisture by solvent swelling mechanisms leads to an interesting technical issue. It is well known that simple drying of low rank coals at minemouth is ineffective because the process is reversible, to a significant degree. The economic advantages of preshipment drying have however dictated a search for ``permanent`` drying procedures. These have been developed by largely empirical means, and involve mild pyrolytic treatments of the coals in oil, steam or liquid water itself The idea has always been to pyrolytically remove oxygen groups, which are assumed to be those that hold water most strongly by hydrogen bonding. The treatments have been designed to minimize tar formation and decrepitation of the particles, both highly undesirable. In relation to the present new hypothesis concerning water retention, it is likely that a sound approach to permanent drying would involve highly crosslinking the coal at mild drying conditions. The crosslinked coal could not swell sufficiently to hold much water. It is identifying processes to achieve this goal, that constitute the objective of the second phase of this work.

Suuberg, E.M.; Yun, Y.; Lilly, W.D.; Leung, K.; Gates, T.

1992-12-31

388

Transfer of Internalized E. coli O157:H7 from Cut Lettuce During Simulated Dewatering Process and Effect of Sanitizer Use in Preventing Cross Contamination  

E-print Network

and Effect of Sanitizer Use in Preventing Cross Contamination Manishkumar S. Patel1 and Tong-Jen Fu2 1 and evaluated the efficacy of sanitizer use in preventing batch cross contamination. Romaine lettuce leaves were/ml and -0.9 log cfu/g, respectively. The effect of sanitizer use in preventing cross contamination

Heller, Barbara

389

Pharmaceutical and personal care products in tile drainage following surface spreading and injection of dewatered municipal biosolids to an agricultural field  

Microsoft Academic Search

Land application of municipal biosolids can be a source of environmental contamination by pharmaceutical and personal care products (PPCPs). This study examined PPCP concentrations\\/temporally discrete mass loads in agricultural tile drainage systems where two applications of biosolids had previously taken place. The field plots received liquid municipal biosolids (LMB) in the fall of 2005 at an application rate of ?93,500 L

M. Edwards; E. Topp; C. D. Metcalfe; H. Li; N. Gottschall; P. Bolton; W. Curnoe; M. Payne; A. Beck; S. Kleywegt; D. R. Lapen

2009-01-01

390

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 March--31 May 1992  

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? The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation processes, is possibly in error. This seems to be a very real possibility for low rank coals, i.e. lignites. To explore this hypothesis further requires an examination of the basic phenomena governing the swelling of coals in good solvents. This is the focus of the first part of this project. The possibility that coal holds a significant portion of its moisture by solvent swelling mechanisms leads to an interesting technical issue. It is well known that simple drying of low rank coals is ineffective because the process is reversible, to a significant degree. Pyrolytic treatments of the coals in oil, steam or liquid water itself. Pyrolytically remove oxygen groups, which are assumed to be those that hold water most strongly by hydrogen bonding. The treatments have been designed to minimize tar formation and decrepitation of the particles, both highly undesirable. In relation to the present new hypothesis concerning water retention, it is likely that a sound approach to permanent drying would involve highly crosslinking the coal at mild drying conditions. The crosslinked coal could not swell sufficiently to hold much water. It is identifying processes to achieve this goal, that constitute the objective of the second phase of this work.

Suuberg, E.M.

1992-12-18

391

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, December 1, 1991February 28, 1992  

Microsoft Academic Search

The possibility that coal holds a significant portion of its moisture by solvent swelling mechanisms leads to an interesting technical issue. It is well known that simple drying of low rank coals at minemouth is ineffective because the process is reversible, to a significant degree. The economic advantages of pre-shipment drying have however dictated a search for ``permanent`` drying procedures.

Suuberg

1992-01-01

392

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 March31 May 1992  

Microsoft Academic Search

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? The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation

Suuberg

1992-01-01

393

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 June31 August, 1992  

Microsoft Academic Search

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? The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary

E. M. Suuberg; Y. Yun; W. D. Lilly; K. Leung; T. Gates

1992-01-01

394

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 September 1991--30 November 1991  

Microsoft Academic Search

This project is concerned with the ability of coal to hold moisture is it a manifestation of the well-known ability of coal to swell, when exposed to good solvents? The question implies that the long-held belief that coal holds a significant portion of its moisture by classical capillary condensation processes, is possibly in error. To explore this hypothesis further requires

Suuberg

1991-01-01

395

Principal component analysis and modeling of the subsidence of the shoreline of Lake Taupo, New Zealand, 1983–1999: Evidence for dewatering of a magmatic intrusion?  

Microsoft Academic Search

Principal component analysis was applied to a set of relative water level measurements made at 22 sites around Lake Taupo, New Zealand, in 37 surveys during 1986–1996. Only a single mode was significantly above noise levels. This mode showed a subsidence of the lake shore that decayed exponentially with time, with a time constant of about 12 years. The mode

Euan G. C. Smith; Timothy D. Williams; Desmond J. Darby

2007-01-01

396

Occurrence of Listeria sp. and L. monocytogenes in sewage sludge used for land application: effect of dewatering, liming and storage in tank on survival of Listeria species  

Microsoft Academic Search

The application of sewage sludge to agricultural land is widely used in France. To determine the impact of sludge treatments, concentrations of Listeria sp., Listeria monocytogenes and faecal indicators were monitored in five types of sludge from three sewage treatment plants in Angers (France) and its suburbs over a 1-year period. On the whole, bacteria were reduced in numbers through

N Garrec; F Picard-Bonnaud; A. M Pourcher

2003-01-01

397

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

DOEpatents

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Vijayan, Sivaraman (Deep River, CA); Wong, Chi F. (Pembroke, CA); Buckley, Leo P. (Deep River, CA)

1994-01-01

398

Use of a single-bowl continuous-flow centrifuge for dewatering suspended sediments: effect on sediment physical and chemical characteristics  

USGS Publications Warehouse

Sediment-recovery efficiency of 86-91% is comparable to that of other types of CFC units. The recovery efficiency is limited by the particle-size distribution of the feed water and by the limiting particle diameter that is retained in the centrifuge bowl. Contamination by trace metals and organics is minimized by coating all surfaces that come in contact with the sample with either FEP or PFA Teflon and using a removable FEP Teflon liner in the centrifuge bowl. -from Authors

Rees, T. F.; Leenheer, J. A.; Ranville, J. F.

1991-01-01

399

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

DOEpatents

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

Vijayan, S.; Wong, C.F.; Buckley, L.P.

1994-11-22

400

Development of ceramic material and filtering element technology for disk vacuum filtering units used in dewatering ferrous and nonferrous metal ore concentrates  

Microsoft Academic Search

Question of reducing expenditure for producing a production unit may be resolved by means of filtering elements made of porous\\u000a permeable ceramic materials with a controlled pore size created using the newest technology. Methodology is presented for\\u000a creating sector filtering elements made of porous permeable ceramic based on electrocorundum for disk vacuum filtering units\\u000a used extensively in ferrous and nonferrous

B. L. Krasnyi; V. P. Tarasovskii; A. B. Krasnyi

2009-01-01

401

Dr. H.M. Watt Project QA Officer  

E-print Network

and the associated trenching diverts and ponds ground water. Second is the dewatering during construction or treatment. Also, dewatering has been poorly monitored in the district. Land use is extremely critical

District of Columbia, University of the

402

Regional P wave velocity structure of the Northern Cascadia Subduction Zone  

E-print Network

of the upper fore-arc mantle and provide evidence for slab dewatering and densification. Tertiary sedimentary region of slab dewatering and densification and may therefore partly result from a higher rate of slab

Ramachandran, Kumar

403

Investigation of EPS Characteristics and their Effects on Waste Activated Sludge Digestion  

E-print Network

activated sludge (WAS) from wastewater treatment plants (WWTP) demands extensive sludge dewatering, and dewatering performance were made over time. · Certain extraction techniques have been shown to release EPS

Mountziaris, T. J.

404

Chi-man Leung Jiu J. Jiao  

E-print Network

be weakened. Besides, excess Ca2+ may deposit in the dewatering systems in the area, which may affect Department. Discussion of the behavior of Ca2+ is instructional to foundation and slope dewatering designs

Jiao, Jiu Jimmy

405

MINE DEVELOPMENT SURFACE WATER  

E-print Network

Mine Engineering Plan Surface Water Components Site Drainage Mine Site Dewatering (If covered Dewatering Open Pit Lake Drain site / Water Disposal Mine Site Runoff Dikes Seepage Underground Mine Rivers

Boisvert, Jeff

406

Transactions of the American Fisheries Society 128:222240, 1999 Copyright by the American Fisheries Society 1999  

E-print Network

of seasonal shifts in flow on simulated dewatering of redds was equally important and tended to compensate (dewatering, scouring, and temperature-related mortality) also lead to nonadditive effects of the two climatic

Jager, Henriette I.

407

CREATE A SAFE CONSTRUCTION  

E-print Network

undisturbed soil samples and test the strength of soils with low cohesion. We can implement dewatering before subsurface excavation for foundations. This frequently involves the use of submersible "dewatering" pumps

Shihadeh, Alan

408

ISpacecraft Habitation and Waste Management SystemsSpacecraft Habitation and Waste Management Systems Technical Abstract  

E-print Network

development will recover virtually all of the remaining water using an ultrasonic brine dewatering system.D. (541) 863-2653 akse@urcmail.net 2008 Phase II Proposal X2.03-8729 Brine Dewatering Using Ultrasonic

409

Groundwater flow to a horizontal or slanted well in an unconfined aquifer  

E-print Network

are useful for the parameter identification, design of remediation systems, drainage, and mine dewatering, and mine dewatering [Hantush and Papadopulos, 1962]. [4] An early study of fluid flow to a horizontal well

Zhan, Hongbin

410

propagate away from the wells and disturbs a larger and larger volume, the probability increases  

E-print Network

be linked to disposal of fluids gen- erated during Oklahoma dewatering and after hydraulic fracturing, and Missis- sippi Lime dewatering plays. The injection-linked seismicity near Jones occurs up to 35 km away

Benton, Michael

411

Comparison of computation methods for CBM production performance  

E-print Network

methane production is somewhat complicated and has led to numerous methods of approximating production performance. Many CBM reservoirs go through a dewatering period before significant gas production occurs. With dewatering, desorption of gas...

Mora, Carlos A.

2009-06-02

412

Evaluate Spawning of Fall Chinook and Chum Salmon just Below the Four Lowermost Columbia River Mainstem Dams  

E-print Network

to estimate loss from dewatering of redds or juvenile stranding. With continued CWT of the juvenile wild fall to document the level of take that occurs from stranding and the dewatering of redds. In the Ives Island

413

40 CFR 421.153 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

...000 Fluoride 0.000 0.000 (k) Beryl Ore Gangue Dewatering. BAT Limitations for the Primary Beryllium Subcategory...Fluoride 36.505 20.756 (l) Bertrandite Ore Gangue Dewatering. BAT Limitations for the Primary Beryllium...

2014-07-01

414

40 CFR 421.156 - Pretreatment standards for new sources.  

...000 Fluoride 0.000 0.000 (k) Beryl Ore Gangue Dewatering. PSNS for the Primary Beryllium Subcategory Pollutant...Fluoride 36.505 20.756 (l) Bertrandite Ore Gangue Dewatering. PSNS for the Primary Beryllium Subcategory...

2014-07-01

415

The big crunch: Physical and chemical expressions of arc/continent collision in the Western Bismarck arc  

E-print Network

occurring suggests that either slab dewatering is not essential for initiating volcanism or that the process of dewatering continues long after subduction has ceased. Limited data from similar collision zones elsewhere

Sandiford, Mike

416

Bogen, N. L.; Girty, G. H.; Hanson, R. E.; Merguerian, Charles; and Schweickert, R. A., 1980, Contrasting styles of deformation during the Nevadan Orogeny, Sierra Nevada,  

E-print Network

that strain hardening and dewatering had already occurred in the pre-Nevadan terranes, while Jurassic rocks may have undergone compaction and dewatering during the orogeny. To Cite This Abstract: Bogen, N. L

Merguerian, Charles

417

9th World Wide Workshop for Young Environmental Scientists WWW-YES-Brazil-2009: Urban waters: resource or risks? 26-30 October 2009  

E-print Network

for domestic and industrial wastewater treatment, faecal sludge dewatering, stabilisation, and humification 1997). In Cameroon, 150­240 tons DM/ha/y of E. pyramidalis cultivated on faecal sludge dewatering beds

Paris-Sud XI, Université de

418

Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds  

E-print Network

to these operational conditions, dewatering efficiencies reached approx. 30% DM during summer but less than 20%DM with dewatering (drainage and evapotranspiration) and aerobic mineralisation. The main idea of this study

Paris-Sud XI, Université de

419

ASSOCIATION OF WASTE STABILISATION PONDS AND INTERMITTENT SAND FILTERS  

E-print Network

of the 1st pond will be spread each day on four Sludge Dewatering Reed Bed Filters(SDRBF). The beginning sandfilters,pilots, rain water, sludge dewatering reed bedsfilters,waste stabilisation ponds, wastewater

Paris-Sud XI, Université de

420

Low-grade metamorphism around the down-dip limit of seismogenic subduction zones: Example from an ancient  

E-print Network

a subduction zone are progressively modified by dewatering, lithification, and deformation (Cowan, 1982; Byrne­aseismic transitions occurs at temperatures of ~150 °C and is believed to be related to dewatering of subducted

Paris-Sud XI, Université de

421

78 FR 4165 - Notice of Availability of the Draft Environmental Impact Statement for the Arturo Mine Project...  

Federal Register 2010, 2011, 2012, 2013

...surface disturbance on public lands administered by the BLM. While dewatering is not proposed for this project, pit lakes would form as a result of cessation of dewatering at Goldstrike Mine, located approximately 8 miles to the...

2013-01-18

422

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

Code of Federal Regulations, 2010 CFR

...ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene...does not apply to releases of the PMN substance during the dewatering step of the polymerization reactions from use. (b)...

2010-07-01

423

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

Code of Federal Regulations, 2011 CFR

...ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene...does not apply to releases of the PMN substance during the dewatering step of the polymerization reactions from use. (b)...

2011-07-01

424

Mechanisms in Compressible Cake Filtration.  

National Technical Information Service (NTIS)

Basic mechanisms influencing filtration dewatering of compressible water and wastewater sludges were examined. Results revealed many hitherto unappreciated aspects of filtration dewatering and pointed out the lack of reliability of present means for chara...

R. I. Dick

1989-01-01

425

77 FR 75644 - Malheur National Wildlife Refuge, Harney County, OR; Final Comprehensive Conservation Plan and...  

Federal Register 2010, 2011, 2012, 2013

...Double-O Units would be managed using rotational flooding and dewatering, to enhance productivity for waterfowl and to control carp...highly prescriptive grazing, mowing, farming, and extended dewatering, to reclaim acres overrun with invasive common cattail...

2012-12-21

426

78 FR 7808 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Buffalo Valley...  

Federal Register 2010, 2011, 2012, 2013

...would consist of the following components: 2 open pits; mine dewatering system; 3 waste rock storage areas; crushing system; heap...preliminary issues: pit lake formation post closure, mine dewatering, wildlife, and socioeconomic concerns. The BLM will...

2013-02-04

427

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

Code of Federal Regulations, 2012 CFR

...ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene...does not apply to releases of the PMN substance during the dewatering step of the polymerization reactions from use. (b)...

2012-07-01

428

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

Code of Federal Regulations, 2013 CFR

...ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene...does not apply to releases of the PMN substance during the dewatering step of the polymerization reactions from use. (b)...

2013-07-01

429

Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/watres  

E-print Network

produced during the dewatering of digested biomass (i.e., the centrate) is commonly mixed with the influent are biogas and stabilized biomass. When the digested biomass is dewatered using a centrifuge, a biosolids

430

Energy Efficiency Improvements and Cost Saving Opportunities in the Corn Wet Milling Industry  

E-print Network

has usually been done in multiple effect evaporators (3-5 effects), but mechanical vapor recompression (MVR) has been used as well since the early 1990's (1). The com steep liquor is used for commercial purposes as an ingredient in animal feed... dewatering Germ dewatering Fiber dewatering Starch dewatering filters Drying Technology Process integration/pinch technology Multiple effect evaporators Controls on heaters between steps Thermal and mechanical vapor recompression Reusing waste...

Galitsky, C.; Worrell, E.

431

CITY OF PRINCE GEORGE: RADIO FREQUENCY TREATMENT OF PARTIALLY  

E-print Network

#12;CITY OF PRINCE GEORGE: RADIO FREQUENCY TREATMENT OF PARTIALLY DIGESTED/DEWATERED BIOSOLIDS/DEWATERED BIOSOLIDS FINAL REPORT SUMMARY The City of Prince George recently proposed to investigate the possibility of applying radio frequency (RF) technology to partially digested/dewatered biosolids from domestic wastewater

432

Proceedings of IMECE 2001 2001 ASME International Mechanical Engineering Congress & Exposition  

E-print Network

% of the water from pulp is sequentially removed through gravity, vacuum dewatering, pressing, and thermal drying- rogate measurements, and the pressure settings in the multiple vacuum dewatering boxes are adjusted- ity, vacuum dewatering, mechanical press, and thermal drying in a paper machine, to form end product

Li, Perry Y.

433

PLEASE SCROLL DOWN FOR ARTICLE This article was downloaded by: [University of Minnesota  

E-print Network

://www.informaworld.com/smpp/title~content=t713597247 Method to Characterize the Air Flow and Water Removal Characteristics During Vacuum Dewatering and Water Removal Characteristics During Vacuum Dewatering. Part II--Analysis and Characterization;Method to Characterize the Air Flow and Water Removal Characteristics During Vacuum Dewatering. Part II

Li, Perry Y.

434

Water quality Water quantity  

E-print Network

· Traditionally only really interested in dewatering (MinE 413, 414) · Now more interested in prediction operations ­ Dewatering activities ­ Seepage from waste rock piles and tailings ­ Flooded mine workings/decrease) · Impacts from dewatering: ­ Decreased flow in streams (if hydraulically connected to the groundwater source

Boisvert, Jeff

435

TEXT UPDATED: 2/16/2012 FIRST OPEN SOLICITATION  

E-print Network

has patented a cost-effective dewatering technology that separates micro-solids (algae) from water analysis, dewatering 1 ton of algae in a centrifuge costs around $3,400. AVS's Solid-Liquid Separation (SLS technology uses capillary dewatering with filter media to gently facilitate water separation, leaving behind

Rollins, Andrew M.

436

Peter Leete DNR Transportation Hydrologist, and MnDOT Liaison  

E-print Network

Invasive species Navigation Dewatering Demolition & Construction Hydrologic Modeling Fish Passage.htmlwww.dnr.state.mn.us/watertrails/location_map.html #12; Note that the MPCA GP also has dewatering conditions (Part IV section D). Conditions differ in language, but essentially say the same "All water from dewatering ...must be discharged in a manner

Minnesota, University of

437

subsidence from ratesofverticalmotion(cmyr-1  

E-print Network

when stressed, hence, buried sediments undergo dewatering. Compaction is strongly time assumes instantaneous dewatering, an unlikely scenario. Much of the pre-Holocene interval is either undercompacted (overpressured) or was compacted prior to the Holocene because of early dewatering during sea

Kulp, Mark

438

Page 1 of 5 Installation Name ____________________________________________________________  

E-print Network

to facilitate the performance evaluation of solids dewatering systems used for maximizing the solids content Treatment Objectives Solids dewatering is typically used to remove excess water from sludges generated by chemical precipitation of metals (e.g., cadmium, chromium, copper, lead, nickel, zinc), dewatering

US Army Corps of Engineers

439

Using water activity measurements to evaluate rheological consistency and structure strength of sludge  

E-print Network

and for predicting its structural, textural and mechanical properties during dewatering and ageing. Keywords: rheology; water activity; sewage sludge; network strength, flocculation; dewatering; ageing 1. Introduction, published in "" #12;2 design of pumping systems or for the control of the dewatering steps [1]. Slatter [2

Paris-Sud XI, Université de

440

Transactions of the Institute of Measurement and Control 25,1 (2003) pp. 3656 Pre-emptive control of moisture  

E-print Network

of over 90% of the water from pulp through gravity, vacuum dewatering, pressing and thermal drying, and the pressure settings in the vacuum dewatering boxes are adjusted accord- ing to the surrogate measurements; vacuum dewatering Address for correspondence: Perry Y. Li, Department of Mechanical Engineering

Li, Perry Y.

441

HAR Microfluidic Device to Concentrate Microalgae , Q. Nguyen1  

E-print Network

in the traditional processing comes from concentrating (dewatering) the algae from the dilute growing concentrations (~0.1 wt%). A continuous flow microfluidic dewatering chip has been designed using an innovative concentrating (dewatering) the algae from the dilute concentrations (~0.1 wt%) at which they grow [2

442

JOIDESJournal Joint Oceanographic Institutions for Deep Earth Sampling  

E-print Network

the underthrust section near the trench axis. The thinning was interpreted as sediment dewatering due to the load of the overlying plate. These observations suggest that either dewatering is highly dispersed through the lower part of the slope, or dewatering is not accompanied by chemosynthetic vent communities that have been

443

Novel Nanoscale Materials Reduce Electricity Needed for Sludge  

E-print Network

Novel Nanoscale Materials Reduce Electricity Needed for Sludge Dewatering Industrial in California is 2 billion kilowatthours per year. Part of sludge treatment includes dewatering, a process that removes as much water from digested sludge as possible. Dewatering is necessary to reduce the sludge

444

Geosynthetics International, 2004, 11, No. 2 Retention performance of geotextile containers  

E-print Network

of geotextile containers for dewatering applications typically requires hydraulic compatibility between phase of the fill material and must not be clogged during the dewatering process. This becomes difficult and the apparent opening size had little effect on dewatering efficiency; however, the same properties directly

Aydilek, Ahmet

445

PLEASE SCROLL DOWN FOR ARTICLE This article was downloaded by: [University of Minnesota  

E-print Network

://www.informaworld.com/smpp/title~content=t713597247 Method to Characterize the Air Flow and Water Removal Characteristics during Vacuum Dewatering and Water Removal Characteristics during Vacuum Dewatering. Part I--Experimental Method',Drying Technology;Method to Characterize the Air Flow and Water Removal Characteristics during Vacuum Dewatering. Part I

Li, Perry Y.

446

(Created 4/07; Revised 9/07, 6/08, 10/08, 7/09, 7/10, 7/11, 7/12) UNL Environmental Health and Safety (402) 472-4925 http://ehs.unl.edu  

E-print Network

to those cited above. Site disturbing activities and dewatering are both subject to regulatory requirements)." · Some dewatering of excavations or other structures may require application for and compliance with the "General NPDES Permit Authorizing Dewatering Discharges (General NPDES Permit Number NEG671000)." #12

Farritor, Shane

447

Hydrol. Earth Syst. Sci., 15, 17711783, 2011 www.hydrol-earth-syst-sci.net/15/1771/2011/  

E-print Network

Macroinvertebrate community responses to a dewatering disturbance gradient in a restored stream J. D. Muehlbauer1, M � Published: 9 June 2011 Abstract. Dewatering disturbances are common in aquatic systems and represent a relatively untapped field of distur- bance ecology, yet studying dewatering events along gradi- ents in non

Doyle, Martin

448

1 INTRODUCTION Considerable evidence has been provided by the recent studies  

E-print Network

, Pilarczyk 2000, Gaffney 2001) that dewater- ing of contaminated high water content geomaterials may assist in their further remediation. This dewatering has been tradition- ally achieved through exposing them to sunlight to their advantages over the traditional dewatering methods. These advantages include; (1) reduced work volume

Aydilek, Ahmet

449

INTRODUCTION Studies of fluid flow in convergent margins  

E-print Network

the system (Fryer, 1996). These zones show much greater dewatering of subducted sedi- ments, because of expelled pore fluids to seawater chemistry, and the effects of such shallow dewatering on the composition the décollement and the in- creasingly dewatered underthrust sequence below. Site 1040 also bottomed in a gabbro

Fisher, Andrew

450

India: Gujarat  

article title:  Dewatering Effects from the Gujarat Earthquake   ... fountaining from the Earth. These effects, referred to as dewatering, can result from intense ground shaking by strong earthquakes in ... with shallow water tables. Scientists initially observed dewatering in parts of the Rann of Kutch (a large salt pan in northern ...

2013-04-16

451

76 FR 16534 - Hazardous Waste Management System Identification and Listing of Hazardous Waste; Final Exclusion  

Federal Register 2010, 2011, 2012, 2013

...solids that are not captured by the dewatering process for the currently generated...over in the effluent from the sludge dewatering process and settle out in the FEPs as...generated filter cake which escape the dewatering process. EPA agrees with the...

2011-03-24

452

*Corresponding author: Tel: +(33)-(0)4-70-47-74-10/Fax: +(33)-(0)4-70-47-74-11 E-mail: jean-christophe.baudez@cemagref.fr  

E-print Network

LaTEP, rue Jules Ferry, 64075 Pau cedex, France Abstract Even after mechanical dewatering, activated of treatment it comes from, this material is usually highly compressible and known to be difficult to dewater the efficiency of dewatering. This study also discusses the link between sludge dewaterability and cake

Boyer, Edmond

453

APPENDIX A. EQUIPMENT MODIFICATION DESIGN STUDY SUMMARY  

E-print Network

Newark Bay, consisted of 97 percent silt and clay and 3 percent sand. It was originally dewatered) mechanical dewatering and belt conveying to the charging deck, and 3) thermal drying and screw or belt conveying. Mechanical dewatering and conveying the sediment using a belt conveyor was considered the most

Brookhaven National Laboratory

454

Performance characterization of a packed bed electro-filter  

E-print Network

use in the petroleum industry, where the method is used to dewater oils and petroleum fractions (5, 6). This method has also been used in removing inorganic water soluble impurities from non-aqueous media (7). Electro filtration is another... developments in this area, electro-filtration and similar applications such as electro-dewatering and electro-acoustic dewatering are' gaining popularity for use with both aqueous and non-aqueous media. In tests conducted for cross flow electro-filtration (9...

Narayanan, Ajay

2012-06-07

455

The Optimization of Well Spacing in a Coalbed Methane Reservoir  

E-print Network

of a coalbed methane reservoir is presented in Fig. 1.5. As shown in Fig. 1.5., the first stage of production profile is the dewatering process. The dewatering process is a mandatory procedure in a coalbed methane reservoir with higher reservoir... starts to desorb. Fig. 1.5 ? Typical coalbed methane production behavior As shown in Fig. 1.5., the first stage of production profile is the dewatering process. The dewatering process is a mandatory procedure in a coalbed methane reservoir...

Sinurat, Pahala Dominicus

2012-02-14

456

40 CFR 717.7 - Persons not subject to this part.  

...surfactant, plasticizer, corrosion inhibitor, antifoamer or defoamer, dispersant, precipitation-inhibitor, binder, emulsifier, deemulsifier, dewatering agent, agglomerating agent, adhesion promoter, flow modifier, pH adjuster,...

2014-07-01

457

40 CFR 710.4 - Scope of the inventory.  

...plasticizer, corrosion inhibitor, antifoamer or de-foamer, dispersant, precipitation inhibitor, binder, emulsifier, de-emulsifier, dewatering agent, agglomerating agent, adhesion promoter, flow modifier, pH neutralizer,...

2014-07-01

458

40 CFR 717.7 - Persons not subject to this part.  

Code of Federal Regulations, 2012 CFR

...corrosion inhibitor, antifoamer or defoamer, dispersant, precipitation-inhibitor, binder, emulsifier, deemulsifier, dewatering agent, agglomerating agent, adhesion promoter, flow modifier, pH adjuster, sequestrant, coagulant, flocculant,...

2012-07-01

459

40 CFR 717.7 - Persons not subject to this part.  

Code of Federal Regulations, 2013 CFR

...corrosion inhibitor, antifoamer or defoamer, dispersant, precipitation-inhibitor, binder, emulsifier, deemulsifier, dewatering agent, agglomerating agent, adhesion promoter, flow modifier, pH adjuster, sequestrant, coagulant, flocculant,...

2013-07-01

460

Production of green juice with an intensive thermo-mechanical fractionation process. Part II: Effect of processing conditions on the liquid fraction properties  

Microsoft Academic Search

The thermally assisted mechanical dewatering (TAMD) process proved to be efficient to dewater various biomasses. The main idea of this process is to supply heat by conduction through the press walls during the wet fractionation. Applied to spinach leaves, this process led to energy saving but also to a larger amount of green juice. In order to optimize the TAMD

S. Kerfai; A. Fernández; S. Mathé; S. Alfenore; P. Arlabosse

2011-01-01

461

Intern experience at URS Company: an internship report  

E-print Network

mixing facil? ities, flocculation and sedimentation basins, filtration facilities, and sludge handling and dewatering facilities. I was responsible for the design of electrical power distribution, lighting, control, and instru? mentation systems... mixing facil? ities, flocculation and sedimentation basins, filtration facilities, and sludge handling and dewatering facilities. I was responsible for the design of electrical power distribution, lighting, control, and instru? mentation systems...

Elkarmi, Fawwaz, 1950-

2013-03-13

462

Performance monitoring and numerical modelling of a deep circular excavation  

E-print Network

. The hoop strain measurements indicate that the shaft has undergone a three-dimensional deformation pattern during a dewatering trial prior to shaft excavation. The parametric study on wall anisotropy suggests that the shaft wall be- haved like a cylindrical... . . . . . . . . . . . . . . . . 117 xii Contents 5.3.4 Ground movement . . . . . . . . . . . . . . . . . . . . . . 122 5.4 Diaphragm wall construction . . . . . . . . . . . . . . . . . . . . 129 5.5 Dewatering trial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 5...

Schwamb, Tina

2014-07-01

463

Terra Contracting, LLC "Exceptional Environmental Services"  

E-print Network

C.4.1 General 8 C.4.2 Hydraulic Barrier 8 C.4.3 Bypass Pumping System 8 C.4.4 Dewatering Activities-SS-15 11 C.5.5 Confirmation Sampling 12 C.5.6 Air Sampling 13 C.5.7 Sediment Dewatering/Drying Pad 13 C

464

Moisture distribution in activated sludges: a review  

Microsoft Academic Search

The dewatering of residual sludges is a current problem due to the huge production of this waste. Activated sludges are generally hard to dewater, and the design and the control of the separation operations are often quite difficult. In order to better understand this problem, pertinent indices are needed. The knowledge of how water is distributed within activated sludge is

J. Vaxelaire; P. Cézac

2004-01-01

465

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

466

40 CFR 421.154 - Standards of performance for new sources.  

...of 7.5 to 10.0 at all times. (k) Beryl Ore Gangue Dewatering. NSPS for the Primary Beryllium Subcategory Pollutant...5 to 10.0 at all times. (l) Bertrandite Ore Gangue Dewatering. NSPS for the Primary Beryllium Subcategory...

2014-07-01

467

40 CFR 421.152 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

...of 7.5 to 10.0 at all times. (k) Beryl Ore Gangue Dewatering. BPT Limitations for the Primary Beryllium Subcategory...5 to 10.0 at all times. (l) Bertrandite Ore Gangue Dewatering. BPT Limitations for the Primary Beryllium...

2014-07-01

468

24. Pump Room interiordewatering pump motor on upper level. Note ...  

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

24. Pump Room interior-dewatering pump motor on upper level. Note the removable roof hatch (steel frame) directly above motor. Dewatering pumps motor control center at left - Hunters Point Naval Shipyard, Drydock No. 4, East terminus of Palou Avenue, San Francisco, San Francisco County, CA

469

Environmental biology of fishes  

SciTech Connect

Extensive water use may alter stream flows so that areas used by spawning salmonids are dewatered, thus exposing intergravel development phases to suddenly changed physical and chemical conditions. Environmental alteration may result in considerable mortality, particularly of the more vulnerable post-hatch phases. Five documented case histories of redd dewatering are reviewed. The primary conditions in the gravel that influence survival during dewatering are residual flow, moisture retention, temperature, gravel composition, dissolved oxygen, alevin behavior, and species characteristics. These factors are discussed and their complex relationships are evaluated. Considerable variation in intergravel conditions can be expected during dewatering at different locations. Onsite studies are needed to obtain data for assessment of potential impacts in other dewatering situations, and for development of effective mitigation procedures. 4 figs.

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

1983-06-01

470

Reducing the moisture content of clean coals  

SciTech Connect

Volume four contains the results of an Empire State Electric Energy Research corporation and Electric Power Research Institute (EPRI) funded investigation to evaluate the effects and economics of applying ultrasonic waves to commercial-scale dewatering and classifying of fine coal. Pre-treating minus 28 mesh Upper Freeport Seam coal using an ultrasonic tray device improved subsequent dewatering by a vacuum disc filter after thickening in a cyclone, but it did not improve dewatering by a screen-bowl centrifuge after cycloning. Dewatering of Pittsburgh Seam coal also improved when the coal was ultrasonically treated, but it only manifested during thickening in the cyclone. Cycloning also increased the removal of fine, high-ash content clay particles from Pittsburgh Seam coal. In contrast, ultrasonically-treating Upper Freeport Seam coal did not improve subsequent classifying by a rapped sieve bend. Based on a specific example of results in this test work for Upper Freeport Seam coal, using an ultrasonic tray to aid dewatering of finely-sized coal can be economically beneficial. For other coals and dewatering devices, however, the economics for using ultrasonic trays to enhance fine coal dewatering will differ.

Raleigh, C.E. (CQ, Inc., Homer City, PA (United States))

1992-11-01

471

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

472

DESIGN INFORMATION REPORT: CENTRIFUGES  

EPA Science Inventory

In the 1960s, manufacturers began to design centrifuges specifically for wastewater sludge applications. In addition, sludge thickening and dewatering processes were improved with the introduction of polyelectrolytes for chemical sludge conditioning. The report contains a brief d...

473

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

474

Technologies for Reducing Nutrients in Dairy Effluent  

E-print Network

Dairy operations are looking for new ways to meet new, higher standards set by the state for water quality. This publication explains research results on the effectiveness of two technologies -- a dewatering system and an electrocoagulation system...

Mukhtar, Saqib; Wagner, Kevin; Gregory, Lucas

2007-01-31

475

40 CFR 230.41 - Wetlands.  

...likely to damage or destroy habitat and adversely affect the biological productivity of wetlands ecosystems by smothering, by dewatering, by permanently flooding, or by altering substrate elevation or periodicity of water movement. The addition of dredged...

2014-07-01

476

40 CFR 232.3 - Activities not requiring permits.  

...rotation (e.g., the rotations of rice and soybeans) where such rotation results in the cyclical or intermittent temporary dewatering of such areas. (D) The discharge of dredged or fill material incidental to the emergency removal of sandbars,...

2014-07-01

477

40 CFR 192.31 - Definitions and cross-references.  

...closure milestone activities such as wind blown tailings retrieval and placement on the pile, interim stabilization (including dewatering or the removal of freestanding liquids and recontouring), and emplacement of a permanent radon barrier constructed to...

2014-07-01

478

Fluid Flow, Thermal History, and Diagenesis of the Cambrian-Ordovician Arbuckle Group and Overlying Units in South-Central Kansas  

E-print Network

, related to hydrothermal activity and potential basin dewatering, have been observed in areas affected by MVT deposition (Table 2.1; Young, 2010; Leach and Sangster, 1995; Garven, 1993; Wojcik et al., 1992; Bethke and Marshak, 1990; Garven and Freeze...

King, Bradley Donald

2013-12-31

479

Modified approaches for high pressure filtration of fine clean coal  

SciTech Connect

Removal of moisture from fine (minus 28 mesh) clean coal to 20% or lower level is difficult using the conventional vacuum dewatering technique. High pressure filtration technique provides an avenue for obtaining low moisture in fine clean coal. This paper describes a couple of novel approaches for dewatering of fine clean coal using pressure filtration which provides much lower moisture in fine clean coal than that obtained using conventional pressure filter. The approaches involve (a) split stream dewatering and (b) addition of paper pulp to the coal slurry. For Pittsburgh No. 8 coal slurry, split stream dewatering at 400 mesh provided filter cake containing 12.9% moisture compared to 24.9% obtained on the feed material. The addition of paper pulp to the slurry provided filter cake containing about 17% moisture.

Yang, J.; Groppo, J.G.; Parekh, B.K. [Center for Applied Energy Research, Lexington, KY (United States)

1995-12-31

480

30 CFR 75.389 - Mining into inaccessible areas.  

...ventilation, ventilation controls, and the air quantities and velocities in the affected working section and working place; (2) Dewatering procedures to be used if a penetrated area contains a water accumulation; and (3) The procedures and precautions to...

2014-07-01

481

78 FR 36598 - Petitions for Modification of Application of Existing Mandatory Safety Standards  

Federal Register 2010, 2011, 2012, 2013

...480-volt, three-phase, alternating current submersible pump, to dewater...1) The three-phase, alternating current electric power circuit for the...electrical connections of the pump motor. (c) The low-water...

2013-06-18

482

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 ...

483

The significance of deep-water cryptic bioturbation in slope-channel massive sand deposits of the lower Rio Dell Formation, Eel River basin, California  

E-print Network

- tion, we present criteria for recognizing cryptic bioturbation fabrics: (1) tubes with lithologically. Introduction 1.1. Deep-water massive beds: sediment gravity flows, dewatering, or bioturbation? Generally

Greene, Todd J.

484

Potential for CO2 Sequestration and Enhanced Coalbed Methane Production, Blue Creek Field, NW Black Warrior Basin, Alabama  

E-print Network

basin, Alabama. It considered the injection and production rate, the components of injected gas, coal dewatering, permeability anisotropy, various CO2 soak times, completion of multiple reservoir layers and pressure constraints at the injector...

He, Ting

2011-02-22

485

78 FR 40496 - Notice of availability of the Final Environmental Impact Statement for the Proposed Hollister...  

Federal Register 2010, 2011, 2012, 2013

...project would augment the existing mine water management facilities that include water treatment facilities and rapid infiltration basins by adding underground dewatering wells and by obtaining a National Pollutant Discharge Elimination System...

2013-07-05

486

77 FR 32665 - Notice of Availability of the Draft Environmental Impact Statement for the Hollister Underground...  

Federal Register 2010, 2011, 2012, 2013

...augment the existing mine water management facilities that currently include water treatment facilities and rapid infiltration basins by adding underground dewatering wells and obtaining a National Pollutant Discharge Elimination System permit...

2012-06-01

487

2012 Nationwide Permits, Conditions, District Engineer's Decision, Further Information, and Definitions (with corrections1  

E-print Network

, and Definitions (with corrections1 ) A. Index of Nationwide Permits, Conditions, District Engineer's Decision. Temporary Construction, Access, and Dewatering 34. Cranberry Production Activities 1 Corrections published. Maintenance Dredging of Existing Basins 36. Boat Ramps 37. Emergency Watershed Protection and Rehabilitation

US Army Corps of Engineers

488

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...

489

From metallurgical coal tailings to thermal fuel  

Microsoft Academic Search

McIntyre Mines in Canada recover coal from washery tailings slurry. The tailings are dewatered in Bird screen bowl centrifuges and thermally dried in Joy Holo-Flite dryers. The coal recovered is burned in a power station.

van den Broek

1982-01-01

490

Fuel From Algae: Scaling and Commercialization of Algae Harvesting Technologies  

SciTech Connect

Broad Funding Opportunity Announcement Project: Led by CEO Ross Youngs, AVS has patented a cost-effective dewatering technology that separates micro-solids (algae) from water. Separating micro-solids from water traditionally requires a centrifuge, which uses significant energy to spin the water mass and force materials of different densities to separate from one another. In a comparative analysis, dewatering 1 ton of algae in a centrifuge costs around $3,400. AVS’s Solid-Liquid Separation (SLS) system is less energy-intensive and less expensive, costing $1.92 to process 1 ton of algae. The SLS technology uses capillary dewatering with filter media to gently facilitate water separation, leaving behind dewatered algae which can then be used as a source for biofuels and bio-products. The biomimicry of the SLS technology emulates the way plants absorb and spread water to their capillaries.

None

2010-01-15

491

46 CFR 119.458 - Portable fuel systems.  

Code of Federal Regulations, 2011 CFR

...fuel systems, including portable tanks and related fuel lines and accessories, are prohibited except where used for portable dewatering pumps or outboard motor installations. (b) The design, construction and stowage of portable tanks and related fuel...

2011-10-01

492

40 CFR 436.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

Code of Federal Regulations, 2010 CFR

...for 30 consecutive days shall not exceed— pH (1 ) (1 ) 1 Within the range 6.0 to 9.0. (2) Mine dewatering discharges shall not exceed the following limitations: Effluent characteristic Effluent limitations Maximum for...

2010-07-01

493

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...  

Code of Federal Regulations, 2013 CFR

...best practicable control technology currently available (BPT): (1) Discharges of process generated waste water and mine dewatering discharges, shall not exceed the following limitations: Effluent characteristic Effluent limitations Maximum for...

2013-07-01

494

40 CFR 232.3 - Activities not requiring permits.  

Code of Federal Regulations, 2012 CFR

...rotation (e.g., the rotations of rice and soybeans) where such rotation results in the cyclical or intermittent temporary dewatering of such areas. (D) The discharge of dredged or fill material incidental to the emergency removal of sandbars,...

2012-07-01

495

30 CFR 75.389 - Mining into inaccessible areas.  

Code of Federal Regulations, 2010 CFR

...ventilation, ventilation controls, and the air quantities and velocities in the affected working section and working place; (2) Dewatering procedures to be used if a penetrated area contains a water accumulation; and (3) The procedures and precautions to...

2010-07-01

496

75 FR 38540 - Notice of Availability of Final Supplemental Environmental Impact Statement Updating Cumulative...  

Federal Register 2010, 2011, 2012, 2013

...had been previously authorized, to expand waste rock disposal facilities and leach facilities by 139 acres, to continue dewatering and ground water discharge to Maggie Creek, and to construct associated ancillary facilities. A Notice of Intent to...

2010-07-02

497

46 CFR 134.170 - Operating manual.  

Code of Federal Regulations, 2011 CFR

...leg or leg pad. (10) A description, a diagram, operating guidance for the bilge system, and an alternative method of dewatering. (11) A general arrangement diagram showing the locations of— (i) Watertight and weathertight compartments;...

2011-10-01

498

46 CFR 119.458 - Portable fuel systems.  

Code of Federal Regulations, 2012 CFR

...fuel systems, including portable tanks and related fuel lines and accessories, are prohibited except where used for portable dewatering pumps or outboard motor installations. (b) The design, construction and stowage of portable tanks and related fuel...

2012-10-01

499

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

National Technical Information Service (NTIS)

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 Dewa...

1996-01-01

500

Water Treatment Plant Sludges--An Update of the State of the Art: Part 2.  

ERIC Educational Resources Information Center

This report outlines the state of the art with respect to nonmechanical and mechanical methods of dewatering water treatment plant sludge, ultimate solids disposal, and research and development needs. (CS)

American Water Works Association Journal, 1978

1978-01-01