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1

Peat dewatering: solvent extraction  

SciTech Connect

The objective of this program is to determine the preliminary technical and economic feasibility of using IGT's solvent-extraction process for the dewatering of peat. Parallel objectives of the program are to: identify organic solvents that can be readily used to dewater raw peat by IGT's solvent-extraction process; design, construct, and operate bench-scale equipment for testing the most promising solvents; and estimate the preliminary economics of the process for a commerical-scale peat dewatering plant using a selective solvent. The results indicate that: solvent-extraction dewatering can remove up to 90% of the water in peat; and diethyl ketone (DEK) and benzene appear to dewater peat better than the other solvents tested. A preliminary economic evaluation of solvent-extraction dewatering of peat with DEK shows that the cost of this type of dewatering method is not currently competitive with other peat dewatering methods. (DWC)

Paganessi, J.E.; Mensinger, M.C.; Tsaros, C.L.; Arora, J.

1981-01-01

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

Artificial Dewatering of Peat.  

National Technical Information Service (NTIS)

New information produced by a study of the literature and by outstanding experimental research is presented is this publication. The subjects dealt with are peat production methods based on artificial dewatering, peat structure, and the waterbinding prope...

M. Aho P. Pirkkonen R. Thun T. Peltola V. M. Luukkainen

1988-01-01

4

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

5

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

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 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

8

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

9

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

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

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

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

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

14

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

15

Review of Phosphatic Clay Dewatering Research.  

National Technical Information Service (NTIS)

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

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

1984-01-01

16

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

17

Coal Dewatering: Australian R&D Trends  

Microsoft Academic Search

Coal (and tailings) dewatering is a major R&D priority in Australia and other coal producing countries. Improved dewatering involves understanding and manipulating feed suspension and filter cake characteristics; judicious selection, modification and application of dewatering technology; and control of the process in respect of feed material, operational parameters, and product characteristics. For these areas, this paper analyses R&D needs, summarises

N. C. LOCKHART; C. J. VEAL

1996-01-01

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

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

20

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

21

Highly efficient secondary dewatering of dewatered sewage sludge using low boiling point solvents.  

PubMed

Secondary dewatering of dewatered sludge is imperative to make conventional drying and incineration of sludge more economically feasible. In this study, a secondary dewatering of dewatered sludge with selected solvents (i.e. acetone and ethanol) followed by vacuum filtration and nature drying was investigated to achieve in-depth dewatering. After the entire secondary dewatering process, the sludge was shown to be odourless and the organic matter content was greatly retained. Increased mean particle size of sludge after solvent contact improved solid-liquid separation. With an acetone/sludge ratio of 3:1 (mL:g) in solvent contact and subsequent nature drying at ambient temperature after 24 h, the moisture content of sludge can be reduced to a level less than 20%. It is found that the polysaccharides were mainly precipitated by acetone, whereas the release ratios of protein and DNA were increased significantly as the added acetone volumes were elevated. During nature drying, accumulated evaporation rates of the sludge after solvent contact were 5-6 times higher than original dewatered sludge. Furthermore, sludge after acetone contact had better nature drying performance than ethanol. The two-stage dewatering involves solvent contact dewatering and solvent enhanced evaporation dewatering. Through selecting an appropriate solvent/sludge ratio as well as economical solvents and minimizing the solvent loss in a closed-pilot system, this dewatering process can be competitive in industrial applications. Therefore, this solvent-aided secondary dewatering is an energy-saving technology for effective in-depth dewatering of dewatered sludge and subsequent sludge utilization. PMID:24600846

He, Chao; Chena, Chia-Lung; Xu, Zhirong; Wang, Jing-Yuan

2014-01-01

22

Development of the Centribaric™ Dewatering Technology  

Microsoft Academic Search

The solid-solid separation processes employed by modern coal preparation plants require large amounts of process water. After cleaning, the unwanted water must be removed from the surfaces of the particles using mechanical dewatering equipment such as filters or centrifuges. Unfortunately, the existing processes that are used to dewater fine particles are inefficient in terms of moisture reduction and\\/or solids recovery.

Serhat Keles; Gerald Luttrell; Roe-Hoan Yoon; Tom Estes; Wally Schultz; Peter Bethell

2010-01-01

23

Surface Phenomena in the Dewatering of Coal.  

National Technical Information Service (NTIS)

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 r...

D. V. Keller G. J. Stelma Y. M. Chi

1979-01-01

24

Dewatering fine coal slurries by gel extraction  

Microsoft Academic Search

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

S. H. Gehrke; Lii-Hurng. Lyu

1990-01-01

25

Sewage sludge dewatering using flowing liquid metals  

DOEpatents

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

Carlson, L.W.

1985-08-30

26

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

27

DESIGN MANUAL: DEWATERING MUNICIPAL WASTEWATER SLUDGES  

EPA Science Inventory

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

28

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...

29

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

30

Dewatering behavior of sewage screenings.  

PubMed

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

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

2013-04-01

31

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

32

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

33

New technique for dewatering suspensions. Final report.  

National Technical Information Service (NTIS)

Preliminary tests were conducted at Loyola Marymount University to evaluate the effectiveness of a new technique in dewatering synthetic cellulose suspension, food waste products and municipal and industrial sludges. The technique utilizes sonically induc...

O. S. Es-Said F. R. Tsipena F. Cano

1990-01-01

34

Sludge Dewatering for FGD Products. Final Report.  

National Technical Information Service (NTIS)

Six full-scale desulfurization systems including three lime scrubbing and three limestone scrubbing facilities were evaluated to determine dewatering characteristics of the waste sludges produced. Pilot-scale centrifugation and bench-scale thickening and ...

J. H. Wilhelm R. W. Kobler Y. Naide G. Redfield

1979-01-01

35

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 ...

36

Lignite aided dewatering of digested sewage sludge.  

PubMed

Mechanical dewatering is commonly used to increase the solids content of municipal sludge prior to its disposal. However, if the rate of filtration is slow, mechanical dewatering can be expensive. In this study, the use of lignite to improve the sludge dewatering is investigated. The effectiveness of lignite conditioning of polyelectrolyte-flocculated sludge is examined using mechanical compression tests. Results show that lignite conditioning in conjunction with polyelectrolyte flocculation gives much better dewatering than the polyelectrolyte flocculation alone. Using Darcy's filtration theory, the specific cake resistance and permeability of the compressed cakes are obtained. Both of these parameters are significantly improved after lignite conditioning. Mercury porosimetry tests on compressed cakes show that the porosity of the lignite-conditioned sludge cake is much higher than that of the polyelectrolyte-flocculated sludge and it increases with increasing doses of lignite. The mercury porosimetry results show that the lignite pore volume of pores greater than 0.5 microm are reduced with increasing sludge ratio indicating that sludge is trapped within these pores, whereas smaller pores are unaffected. The yield stress curves for sludge, lignite and sludge-lignite mixtures show that the sludge filter cake is very compressible, but the lignite-conditioned cake has a range of compressibility which although more than lignite indicate that the cake is relatively incompressible at low pressures. Thus, lignite conditioning acts to maintain the permeability of the filter cake during compression dewatering by resisting cake compression. This leads to a trade-off between the rate of dewatering and the solids content of the compressed cake. With lignite conditioning, the dewatering rate can be increased by a factor of five for the same degree of water removal. PMID:19058831

Thapa, K B; Qi, Y; Clayton, S A; Hoadley, A F A

2009-02-01

37

Development of Enzyme Products for Enhancing Biological Sludge Dewatering.  

National Technical Information Service (NTIS)

Dewatering waste activated sludges reduces the cost of subsequent sludge treatment and disposal operations. A major impediment to effective dewatering by various mechanical devices is the ability of waste activated sludge to hold copious quantities of bou...

1988-01-01

38

Dewatering Florida Phosphate Pebble Rock Slime by Freezing Techniques.  

National Technical Information Service (NTIS)

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

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

1971-01-01

39

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

40

Pressurized Electroosmotic Dewatering (PED) Of Fine Coal Suspensions.  

National Technical Information Service (NTIS)

Current dewatering methods for ultra-fine coal suspensions are inadequate and usually require subsequent expensive thermal drying. This unique dewatering method is based on pressurized electroosmosis, the movement of water by an electrical field through a...

L. W. Heath T. Demirel

1985-01-01

41

PRACTICAL ASPECTS OF DEWATERING ENHANCED BY ELECTRO-OSMOSIS  

Microsoft Academic Search

Dewatering mechanism due to electro-osmosis is fairly different from that of mechanical dewataine which has been used conventionally. and electro-osmotic dewatering has Several advantages compared with the mechanical dewatering and it can be remarkably effective for hardly dewaterable sludges such as very fine Particles and gelatinous materials. In electro-osmotically enhanced dewatering, however, it would be a great problem that the

H. Yoshida

1993-01-01

42

An investigation on dewatering kinetics of ultrafine coal  

Microsoft Academic Search

Ultrafine coal dewatering is of great importance to the coal industry due to its impacts on the handling and utilization characteristics of coal products. Commercially available filtration techniques are either ineffective or costly for dewatering of ultrafine coal to the desired moisture level of about 20%. Considerable efforts have been devoted to understanding the dewatering process and developing new technologies

D. Tao; B. K. Parekh; J. T. Liu; S. Chen

2003-01-01

43

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

44

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

45

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

46

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

47

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

48

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...

49

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

PubMed

For an electro-dewatering process of activated sludge (AS), the effect of pH and conductivity of AS, flocculation conditioning and operation factors of horizontal electric field (voltage magnitude, method of applying electric field and distance between plates) were investigated, and the corresponding optimum electro-dewatering conditions were also obtained. The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value (6.93) and conductivity (1.46 mS x cm(-1)). CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process, whereas a slight increase in the electro-dewatering rate. The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes, while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes. The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate. Moreover, the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g x kg(-1), electric field strength of 600 V x m(-1), distance between the two plates of 40 mm, dehydration time of 60 minutes. Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly. PMID:23379170

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

2012-12-01

50

Dewatering studies of fine clean coal  

SciTech Connect

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

Parekh, B.K.

1991-01-01

51

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

52

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

53

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

54

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

55

Dewatering studies of fine clean coal  

Microsoft Academic Search

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.,

Parekh

1991-01-01

56

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

57

Artificial Dewatering of Peat. Symposium held in Jyvaeskylae, Finland on October 15-16, 1991.  

National Technical Information Service (NTIS)

Contents: Mining and Transportation--(Pumping properties of peat slurry and peat digging all-year-round); Dewatering of Peat--(Efficiency and environmental effects of peat dewatering by mechanical pressing; Some fundamental aspects of the dewatering of pe...

E. Alakangas

1992-01-01

58

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

59

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...

2009-10-01

60

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

61

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

62

Development of the screen bowl centrifuge for dewatering coal fines  

Microsoft Academic Search

Dewatering fine clean coal fractions, -595 MUm (-28 mesh), represents one of the most difficult and costly separations in typical plant circuits. The screen bowl centrifuge offers an economical alternative to filtration\\/thermal drier combinations. The performance of screen bowl centrifuges has been continuously modified and improved to dewater not only coarse coals, but also ultrafine material. Tests comparisons with alternative

N. D. Policow; J. S. Orphanos

1983-01-01

63

Effects of Vacuum Filtration Parameters on Ultrafine Coal Dewatering  

Microsoft Academic Search

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

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

2000-01-01

64

Dewatering press liquor derived from orange production by forward osmosis  

Microsoft Academic Search

In this investigation, a forward osmosis (FO) dewatering process is evaluated as an alternative for dewatering orange peel press liquor. The press liquor is concentrated by removing water via osmosis into a concentrated “draw solution” across a polymeric cellulose acetate membrane. For this investigation, the draw solution consisted of sodium chloride at two different concentrations (2M and 4M). These draw

Esperanza M. Garcia-Castello; Jeffrey R. McCutcheon

2011-01-01

65

Dewatering fine coal slurries by gel extraction. Final report  

Microsoft Academic Search

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

S. H. Gehrke; Lii-Hurng Lyu

1990-01-01

66

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

67

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

68

Characteristics of biosolids in dimethyl ether dewatering method.  

PubMed

In this study, a method for removing water from biosolids that uses dimethyl ether (DME) as an extractant was considered. This study evaluates the applicability of the DME dewatering method to biosolid cakes by using a DME flow-type experimental apparatus. It was found that a high dewatering ratio is clearly achieved by increasing the liquefied DME/biosolid ratio and lowering the liquefied DME linear velocity. As the liquefied DME/biosolid ratio was increased, the carbon content in dewatered biosolid showed a slight decrease and the TOC concentration in separated liquid increased significantly. Finally, the input energy Es to remove 1 kg of water from the biosolid cake, using both the DME dewatering method and the conventional drying method was estimated. The calculation shows that Es for the DME dewatering process is approximately a third of Es for the conventional thermal drying process. PMID:22515061

Oshita, Kazuyuki; Takaoka, Masaki; Nakajima, Yusuke; Morisawa, Shinsuke; Kanda, Hideki; Makino, Hisao; Takeda, Nobuo

2012-02-01

69

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...

2009-10-01

70

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

71

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

Code of Federal Regulations, 2013 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...

2013-10-01

72

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

73

Compression and swelling of activated sludge cakes during dewatering.  

PubMed

A drainage/filtration apparatus was developed for automatically determining sedimentation velocity and dewatering rate. Pressure-step testing was used to study filter cake compressibility, resistance, and swelling. Activated sludge was analysed, and the data indicate that the sludge is highly compressible even at low pressures (10 kPa). Furthermore, compressed sludge cakes swell if the pressure is released. Hence, the average specific cake resistance decreases if the pressure is released, though the resistance is higher after the compression cycle than before. Sludge must be dewatered under low pressure, because higher pressure only compresses the cake and does not improve the dewatering rate. PMID:22819870

Sveegaard, Steffen Gralert; Keiding, Kristian; Christensen, Morten Lykkegaard

2012-10-15

74

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

75

Dewatering studies of fine clean coal  

SciTech Connect

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

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

1991-01-01

76

Dewatering Systems and Techniques for Coalbed Methane Wells. Volume 2.  

National Technical Information Service (NTIS)

The study shows that contemporary oil field systems are adequate for coalbed dewatering. In general, sucker rod systems were preferred for the shallower depths with fluid-operated systems more applicable for the deeper wells. No system was an overwhelming...

1983-01-01

77

Process for the thermal dewatering of young coals  

SciTech Connect

An economic process for thermally dewatering a solid carbonaceous material containing substantial amounts of chemically attached water is disclosed. The process is capable of economically removing up to 95% of the chemically attached water in the disclosed process.

Chang, T.Y.

1984-12-11

78

Evaluation of hyperbaric filtration for fine coal dewatering. Final report.  

National Technical Information Service (NTIS)

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 c...

B. K. Parekh R. Hogg A. Fonseca

1996-01-01

79

Sludge dewatering using centrifuge with thermal/polymer conditioning.  

PubMed

Sludge dewatering is preceded by a conditioning operation to enhance water removal efficiency. In the conditioning operation, chemical coagulants or polymers are added to promote sludge particle aggregation for easier dewatering. In this study, an alternative conditioning method for sludge thermal treatment at temperatures up to 80 degrees C was extensively investigated. Dewatering characteristics such as sludge capillary suction time and specific resistance to filtration, sludge viscosity and concentration of solid cakes were examined thoroughly. A good correlation between capillary suction time and specific resistance to filtration was established for sludges from water treatment, but not for biological sludge. Cationic polymer exhibits the best enhancement on sludge moisture removal. The sludge rheogram varies from 60 to 5 cP as temperature changes from 20 to 80 degrees C for sludges from water treatment plant. The dewatering ability of sludge can be greatly enhanced by thermal treatment in conjunction with the use of polymers. PMID:11794673

Lin, C F; Shien, Y

2001-01-01

80

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

81

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

82

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

83

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

84

Rejektvatten fraan torvavvattning. Jaemfoerelse mellan avvattning i laboratorie- och pilotskala. (Waste water from dewatering of peat. Comparison between dewatering in laboratory- and pilot scale).  

National Technical Information Service (NTIS)

Mechanical dewatering of peat produces a lot of waste water. Earlier studies have shown that waste water from mechanical dewatering of peat in some cases may be toxic. At the Center for Peat Research, CTF, peat is studied both from dewatering and characte...

K. Bergner L. Ringqvist

1991-01-01

85

Development of the screen bowl centrifuge for dewatering coal fines  

SciTech Connect

Dewatering fine clean coal fractions, -595 MUm (-28 mesh), represents one of the most difficult and costly separations in typical plant circuits. The screen bowl centrifuge offers an economical alternative to filtration/thermal drier combinations. The performance of screen bowl centrifuges has been continuously modified and improved to dewater not only coarse coals, but also ultrafine material. Tests comparisons with alternative methods show the screen bowl centrifuge to be most cost-effective and efficient when all factors are considered.

Policow, N.D.; Orphanos, J.S.

1983-04-01

86

Electroosmotically enhanced dewatering\\/deliquoring of fine-particle coal  

Microsoft Academic Search

This research is an investigation of the use of electroosmosis to dewater\\/deliquor ultrafine coal. Post-beneficiation dewatering\\/deliquoring methods for ultrafine coals are inadequate and generally require subsequent thermal drying. The first year of this project focused on preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. The second and final

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

1990-01-01

87

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

88

Dewatering Ultrafine Clean Coal in a T. H. Filter Press  

Microsoft Academic Search

This study demonstrates a low-cost, high-efficiency filter press technology for dewatering minus 150 µm column flotation clean coal products from two coal mines. Pilot-scale in-plant demonstration of this technology at these two locations provided stable, trouble-free operation while achieving an excellent dewatering performance at a high throughput. At one location, filter cakes with residual total moisture contents in the 20–22% range

A. Patwardhan; Y. P. Chugh; B. J. Arnold; A. N. Terblanche

2006-01-01

89

Filtration and dewatering: review of literature. [117 references  

SciTech Connect

Filtration and dewatering are important aspects of any chemical process involved in producing solid product from a slurry. However, these operations are not studied in as much detail as other industrial operations like distillation, absorption, etc. In the past, the design of filtration equipment was considered more of an art than science. Only in the last few years have attempts been made to understand the fundamental mechanism underlying these operations. In this review, the present status of filtration and dewatering is discussed, particularly concerning the models used for predicting the rate of filtration and dewatering. Effects of various parameters, size of particles in the slurry, their shape and method of cake formation, etc., on the characteristics of these operations are analyzed. A separate chapter on the use of these processes in coal cleaning is included. Dewatering of fine coal and refuse has attracted a great deal of attention in recent years. Special problems associated with dewatering of fine coal are discussed. Enhanced methods of dewatering are reviewed and finally areas requiring further research are highlighted.

Gala, H. B.; Chiang, S. H.

1980-09-01

90

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

91

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

National Technical Information Service (NTIS)

Battelle is undertaking engineering development of 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 acou...

B. C. Kim C. L. Criner H. Wu R. Menton N. Senapati

1990-01-01

92

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

93

Improvement of sedimentation and dewatering of municipal sludge by radiation  

NASA Astrophysics Data System (ADS)

As the promotion of sewerage system, the volume of municipal sludge in Tokyo has increased rapidly. Due to recent changes in the properties of the sludge, moreover, it has become difficult to thicken the liquid sewage sludge by sedimentation and to dewater the thickening sludge mechanically. The development of a new effective method for sludge treatment is necessary. Therefore, a study on the improvement of sedimentation and dewatering of sewage sludge by irradiation with 60Co gamma rays and electron beams was undertaken. Sedimentation tests and various dewatering tests were carried out for the waste activated sludge and anaerobically digested sludge. From the changes in the settling rate, capillary suction time, water content of the sludge cake, and the quality of separated water by irradiation, the optimum irradiation conditions for improving the sedimentation and dewatering of 2 types sludge were determined. The necessary dose for improving the sedimentation and dewatering was observed to be 1-3 kGy for the activated sludge and 5-10 kGy for the digested sludge. To confirm the cause of those changes by irradiation, the zeta potential and viscosity of the sludge were measured.

Sawai, Teruko; Yamazaki, Masao; Shimokawa, Toshinari; Sekiguchi, Masayuki; Sawai, Takeshi

94

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

95

Dewatering of floated oily sludge by treatment with rhamnolipid.  

PubMed

Oily sludge dewatering is practically needed prior to sludge treatments. However, the conventional use of physical treatments with or without chemical conditionings presented poor feasibility in industrial applications due to either poor cost-efficiency or lacking environmental friendliness. In this paper, biosurfactant rhamnolipid was for the first time applied for dewatering of oily sludge. Rhamnolipid treatments under the concentration of 300-1000 mg/L, pH of 5-7 and temperature of 10-60 °C could directly separate 50-80% of water from the stable oily sludge. And both mono-rhamnolipid and di-rhamnolipid were identified to be of equivalent dewatering ability, which is closely related to their equivalent performance in breaking the emulsified oil droplets. Demulsification was found to be involved in settling water from oily sludge. Furthermore, the effectiveness of rhamnolipid was further demonstrated at pilot scale (1000 L) treatment of oily sludge. After pilot treatment, the settled water with residual oil of 10 mg/L and soluble COD of about 800 mg/L could be directly effluxed into the biotreatment system while the concentrated oil sludge with a reduced volume by 60-80% can be pumped into coking tower, achieving completely harmless treatment. It seems that rhamnolipid as dewatering agent was of great prospects in the industrial dewatering of oily sludge. PMID:23764581

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

2013-09-01

96

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

97

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

98

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

Microsoft Academic Search

Battelle is undertaking engineering development of 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. The Battelle project for demonstrating the potential for commercial application of the EAD process

B. C. Kim; C. L. Criner; H. Wu; R. Menton; N. Senapati; S. P. Chauhan

1990-01-01

99

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

Microsoft Academic Search

Battelle, in cooperation with the Electric Power Research Institute (EPRI) CQ, Inc., Ashbrook-Simon-Hartley (ASH), 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

B. C. Kim; C. L. Criner; H. Wu; N. Senapati; S. P. Chauhan

1990-01-01

100

The influence of surface phenomena on the dewatering of fine clean coal  

Microsoft Academic Search

The paper presents results of experimental work carried out to study the role of surface active agents in the dewatering of fine clean coal. The fundamental phenomena which determine their mode of action are examined, and the mechanism of surfactant-enhanced dewatering is investigated in terms of the surface chemical phenomena and the physical processes involved in the dewatering. The performance

B. P. Singh

1997-01-01

101

Dewatering of fine coal and refuse slurries-problems and possibilities  

Microsoft Academic Search

Dewatering of fine clean coal and refuse slurry is one of the most important aspects of coal cleaning scenario. It is also adds significant cost to the price of clean coal. This article summarizes the current state-of-the art of dewatering being practiced around the world and discuses some of the upcoming novel dewatering technologies. Hyperbaric filter provides a low moisture

B. K. Parekh

2009-01-01

102

Case Study: Louvered Screen Produces High Efficiency Boreholes for Mine Dewatering - Sub-Saharan Africa  

Microsoft Academic Search

Each dewatering borehole within a dewatering system is designed to accommodate a dedicated pump whose capacity may be several thousand cubic meters of water per day. A typical network of dewatering boreholes (i.e. wellfield) is designed to operate continuously 24 hours-per day without interruption. Its demands for power or fuel are often high, particularly when the efficiencies of the boreholes

103

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

104

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

105

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

106

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

107

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

108

Ultrafine coal single stage dewatering and briquetting process  

Microsoft Academic Search

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

J. W. Wilson; R. Q. Honaker

1995-01-01

109

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

Microsoft Academic Search

The surfactant, Aerosol-OT, was used to wash distilled water cakes. In previous studies, cakes were washed with Triton X-114. The dewatering performance and influence on cake structure of the two reagents are compared. Also, filter cakes were analyzed using an image analysis system and micrographic analysis of coal particles was initiated. In the area of theoretical modelling, the concept of

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

1986-01-01

110

Dewatering of Ultrafine Coal: Final Report, August 1984-December 1986.  

National Technical Information Service (NTIS)

The surfactant, Aerosol-OT, was used to wash distilled water cakes. In previous studies, cakes were washed with Triton X-114. The dewatering performance and influence on cake structure of the two reagents are compared. Also, filter cakes were analyzed usi...

S. H. Chiang G. E. Klinzing B. I. Morsi J. W. Tierney M. Badgujar

1986-01-01

111

Temperature, classification and dewatering in 10 mm hydrocyclones  

Microsoft Academic Search

Small diameter hydrocyclones have had an increasing use in performing difficult phase separations in many industries. Further, these 10 mm diameter hydrocyclones also have the potential to be applied to fine particle classification, in particular to collect the sub-micron fraction.The key operating parameters that affect the dewatering and classification performance of 10 mm hydrocyclones are the operating pressure and feed

J. J. Cilliers; L. Diaz-Anadon; F. S. Wee

2004-01-01

112

Dewatering of phosphorus extracted from liquid swine waste.  

PubMed

Phosphorus (P) recovery from liquid swine manure is an attractive technology when on-farm application of liquid swine manure is not an option. We developed a technology that enables separation of this P, but its high moisture content makes transportation difficult. In this work, we investigated dewatering procedures to concentrate the P product. Sludge rich in calcium phosphate (> 20% P2O5) was obtained using a field prototype, and it was further dewatered using a combination of polymer treatment and filter bags. Anionic polyacrylamide polymer treatment (> or = 20 mg/L) was effective to flocculate the P-rich sludge, which enhanced filtration and dewatering. Without polymer, filtration was incomplete due to clogging of filters. Non-woven polypropylene and monofilament filter bag fabrics with mesh size < or = 200 microm retained > 99% of suspended solids and total P. Solids content dramatically increased from about 1.5% to > 90%. These dewatered solids can be transported more economically off the farm for use as a valuable fertilizer material. PMID:16154515

Szögi, Ariel A; Vanotti, Matias B; Hunt, Patrick G

2006-01-01

113

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

114

ACOUSTIC AND ELECTROACOUSTIC METHODS OF DEWATERING AND DRYING  

Microsoft Academic Search

Interesting results have been observed in applying acoustic energy to dewatering and drying materials. However, drying by acoustic energy alone is expensive, energy intensive, and at best can be justified only in applications where rapid drying is necessary to preserve a product, the product is heat sensitive and its value justified the cost. However, synergistic effects have been observed when

Dale Ensminger; Battelle

1988-01-01

115

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

116

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

117

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

118

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

119

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

120

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

121

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

122

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

123

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

124

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

125

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

126

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

Microsoft Academic Search

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

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

2006-01-01

127

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

128

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

129

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

SciTech Connect

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

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

1986-12-01

130

Improvement of dewatering capacity of a petrochemical sludge.  

PubMed

Oily sludge produced from a petrochemical industry was used to investigate the improvement of its dewatering properties. The oil content (OC) and the dry solid content (DS) of the raw sludge were respectively, 15% and 3.6% by weight. The capillary suction time (CST) and the specific resistance to filtration (SRF) of the raw petrochemical industrial sludge were found to be 2000s and approximately 5.5x10(16)m/kg, respectively. Conventional chemical conditioners such as alum, lime, and polyelectrolyte, and less conventional ones like fly ash, gypsum, and bentonite were used in the sludge conditioning studies. Conventional chemical conditioners gave better results for the enhancement of the dewatering capacity of the sludge. The best result was obtained by using 0.9% cationic polyelectrolyte by weight, and a decrease of 99%-95% were achieved for CST and SRF, respectively, when this dosage of cationic polyelectrolyte was used. PMID:17101214

Buyukkamaci, Nurdan; Kucukselek, Emrah

2007-06-01

131

COMBINED FIELD DEWATERING: BRIDGING THE SCIENCE-INDUSTRY GAP  

Microsoft Academic Search

The author's group is active in research on a wide variety of solid-liquid separation and dewatering methods. Processes examined include coagulation\\/flocculation, sedimentation, consolidation, drainage, filtration, compression\\/expression, and desaturation. A number of mechanical and electrical techniques have been used. These have been applied to a few well-defined systems such as clays, and to a wide variety of real suspensions from different

Neville C. Lockhart

1992-01-01

132

Dewatering and Drying in Mineral Processing Industry: Potential for Innovation  

Microsoft Academic Search

Wet beneficiation of minerals necessarily requires removal of large amounts of water—typically contaminated—before further processing of the concentrated ores can be carried out. Often such concentrates are transported over large instances by ground or sea transport. For economic reasons dewatering\\/drying are essential unit operations. Often the capacity requirements of the mining operations are very large, the product processed has low

Z. H. Wu; Y. J. Hu; D. J. Lee; A. S. Mujumdar; Z. Y. Li

2010-01-01

133

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

134

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

135

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

136

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

137

Electroosmotically enhanced dewatering/deliquoring of fine-particle coal  

SciTech Connect

This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coals are inadequate and generally require subsequent thermal drying. The first year of this project focused on preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. The second and final year was primarily devoted to the electroosmotic dewatering behavior of ultrafine coal. New measurement systems were developed, including a computer-controlled measurement system capable of measuring flow rates as low as 1 {mu}m per second. Furthermore, the effects of gravity, filter attenuation, voltage gradients, electrolysis, and temperature could be either determined explicitly or eliminated as a variable with these systems. Four of the more surprising contributions of this research are: (a) the observation of reversal of electroosmotic flow direction for coal; (b) strong evidence that the primary cause of high-voltage gradients in the coal near the cathode are attributable to reduced conductivity rather than due to trapped hydrolysis-produced hydrogen bubbles; (c) the observation of electroosmotic transport ratios (the ratio of uncharged water molecules removed per single ion removed) sufficiently large to demonstrate that the cost of actual electroosmotic transport of water through ultrafine coal can be very small; and (d) strong evidence that electroosmotic volume flow rates are very insensitive to temperature changes. 10 refs., 5 figs., 9 tabs.

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

1990-11-01

138

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

139

Prediction of the dewatering of selected inorganic sludges.  

PubMed

There are a number of laboratory techniques traditionally used in the characterisation of sludges for the prediction of the efficient operation of dewatering processes such as centrifugation and filtration. In industry, capillary suction time and specific resistance to filtration measurements are common. Whilst useful in predicting trends, they do not assist in the design and optimisation of devices from first principles. Recent work in our laboratories has developed a technique for the fast measurement of the permeability and compressibility of sludge. This information, when coupled with first-principle models is useful for the prediction of the performance of solid-liquid separation devices. The work has shown that a single volume fraction dependent parameter, namely the solids diffusivity, calculated from permeability and compressibility, is able to fully characterise the dewaterability of sludge. This allows different sludges to be compared in an unequivocal fashion. Data will be presented for a range of sludges from different sources showing vastly different dewatering properties. The dewaterability of the different sludges is easily compared and the true role of flocculants in dewatering is highlighted. PMID:11794653

Harbour, P J; Aziz, A A; Scales, P J; Dixon, D R

2001-01-01

140

Synergism in polyethylene oxide dewatering of phosphatic clay waste  

SciTech Connect

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

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

1980-01-01

141

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

142

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

143

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

144

Electrical field: a historical review of its application and contributions in wastewater sludge dewatering.  

PubMed

Electric field-assisted dewatering, also called electro-dewatering, is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. Electro-dewatering is not a new idea, but the practical industrial applications have been limited to niche areas in soil mechanics, civil engineering, and the ceramics industry. Recently, it has received great attention, specially, in the fields of fine-particle sludge, gelatinous sludge, sewage sludge, pharmaceutical industries, food waste and bull kelp, which could not be successfully dewatered with conventional mechanical methods. This review focuses on the scientific and practical aspects of the application of an electrical field in laboratory/industrial dewatering, and discusses this in relation to conventional dewatering techniques. A comprehensive bibliography of research in the electro-dewatering of wastewater sludges is included. As the fine-particle suspensions possess a surface charge, usually negative, they are surrounded by a layer with a higher density of positive charges, the electric double layer. When an electric field is applied, the usually negative charged particles move towards the electrode of the opposite charge. The water, commonly with cations, is driven towards the negative electrode. Electro-dewatering thus involves the well-known phenomena of electrophoresis, electro-osmosis, and electromigration. Following a detailed outline of the role of the electric double layer and electrokinetic phenomena, an analysis of the components of applied voltage and their significance is presented from an electrochemical viewpoint. The aim of this elementary analysis is to provide a fundamental understanding of the different process variables and configurations in order to identify potential improvements. Also discussed herein is the investigation of the electrical behaviour of a porous medium, with particular emphasis on porous medium conductivity determination. PMID:20303137

Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

2010-04-01

145

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

146

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

National Technical Information Service (NTIS)

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

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

1990-01-01

147

Development of the Screen Bowl Centrifuge for the dewatering of coal fines  

Microsoft Academic Search

Dewatering of the fine clean coal fraction. - 28 mesh (595 microns) represents one of the most difficult and costly separations in typical plant circuits. Since 1969, the Screen Bowl Centrifuge has offered an economical alternative to filtration\\/thermal dryer combinations. The performance of Screen Bowl Centrifuges has been continuously modified and improved to dewater not only coarser coals, but also

N. D. Policow; J. S. Orphanos

1982-01-01

148

Development of the Electroacoustic Dewatering (EAD) process for fine\\/ultrafine coal  

Microsoft Academic Search

This report describes an advanced process, called Electroacoustic Dewatering (EAD), which capitalizes on the adaptation of synergistic effects of electric and acoustic fields to commercial coal dewatering systems, such as belt filter presses. Objectives are: (1) to validate the expected technical feasibility and energy conservation\\/economic benefits of the EAD process as applied to fine (-100 mesh) and ultrafine (-325 mesh)

H. S. Muralidhara; B. F. Jirjis; N. Senapati; R. Menton; P. Hsieh; S. H. Chiang; Y. S. Cheng; S. P. Chauhan; Battelle Memorial Inst; OH Columbus

1989-01-01

149

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

Microsoft Academic Search

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

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

2007-01-01

150

Development of the Electroacoustic Dewatering (EAD) process for fine\\/ultrafine coal  

Microsoft Academic Search

Battelle, in cooperation with the Electric Power Research Institute (EPRI), CQ, Inc., Ashbrook-Simon-Hartley (ASH), 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 adaption of synergistic effects of electric and acoustic fields to commercial

B. F. Jirjis; N. Senapati; R. Menton; P. Hsieh; S. P. Chauhan; S. H. Chiang; Y. S. Cheng

1990-01-01

151

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

Microsoft Academic Search

Battelle (Columbus, Ohio) undertook development of its electro-acoustic (EAD) process to demonstrate its commercial potential for continuous dewatering of fine and ultrafine coals. The pilot plant and laboratory results, provided in this report, show that a commercial-size EAD machine is expected to economically achieve the dewatering targets for -100 mesh and -325 mesh coals. The EAD process utilizes a synergistic

S. P. Chauhan; B. C. Kim; R. Menton; N. Senapati; C. L. Criner; B. Jirjis; H. S. Muralidhara; Y. L. Chou; H. Wu; P. Hsieh; H. R. Johnson; R. Eason; S. M. Chiang; Y. S. Cheng; D. Kehoe

1991-01-01

152

Development of the Electroacoustic Dewatering (EAD) process for fine\\/ultrafine coal  

Microsoft Academic Search

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. The Battelle project for demonstrating the potential for commercial application of the EAD process for coal has the following objectives: to validate the expected technical feasibility and energy conservation\\/economic benefits of the EAD process as

B. C. Kim; C. L. Criner; N. Senapati; R. Menton; Y. L. Chou; S. P. Chauhan

1991-01-01

153

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

Microsoft Academic Search

Battelle (Columbus, Ohio) undertook development of its electro-acoustic (EAD) process to demonstrate its commercial potential for continuous dewatering of fine and ultrafine coals. The pilot plant and laboratory results, provided in this report, show that a commercial-size EAD machine is expected to economically achieve the dewatering targets for -100 mesh and -325 mesh coals. The EAD process utilizes a synergistic

S. P. Chauhan; B. C. Kim; R. Menton; N. Senapati; C. L. Criner; B. Jirjis; H. S. Muralidhara; Y. L. Chou; H. Wu; P. Hsieh; H. R. Johnson; R. Eason; S. M. Chiang; Y. S. Cheng; D. Kehoe

1991-01-01

154

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 ...

155

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

156

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 ...

157

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

158

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

159

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...

160

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...

161

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

162

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

163

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

164

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

165

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

166

Fundamental study for improvement of dewatering of fine coal\\/refuse. Annual report, July 1980June 1981  

Microsoft Academic Search

A major area of concern in modern coal preparation plants is the dewatering (and filtration) of fine coal\\/refuse. Fine coal in slurry form must be dewatered to minimize handling and transportation problems and to maximize its calorific value. The current practice is to use a vacuum filter for initial dewatering followed by thermal drying to meet the final moisture requirement.

S. H. Chiang; P. F. Fulton; G. E. Klinzing; J. W. Tierney; H. Gala; R. Kakwani; G. Meenan; H. L. Pien

1981-01-01

167

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

168

OVERVIEW OF REMAINS OF DEWATERING BUILDING, LOOKING SOUTH TOWARD CYANIDE ...  

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

OVERVIEW OF REMAINS OF DEWATERING BUILDING, LOOKING SOUTH TOWARD CYANIDE PROCESSING AREA. WATER USED IN PROCESSING AT THE STAMP MILL WAS CIRCULATED HERE FOR RECLAMATION. SANDS WERE SETTLED OUT AND DEPOSITED IN ONE OF TWO TAILINGS HOLDING AREAS. CLEARED WATER WAS PUMPED BACK TO THE MILL FOR REUSE. THIS PROCESS WAS ACCOMPLISHED BY THE USE OF SETTLING CONES, EIGHT FEET IN DIAMETER AND SIX FEET HIGH. THE REMAINS OF FOUR CONES ARE AT CENTER, BEHIND THE TANK IN THE FOREGROUND. TO THE LEFT IS THE MAIN ACCESS ROAD BETWEEN THE MILL AND THE PARKING LOT. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

169

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

170

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

SciTech Connect

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

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

2006-12-22

171

Application of forward osmosis on dewatering of high nutrient sludge.  

PubMed

A novel approach was designed to simultaneously apply low energy sludge dewatering and nutrient removal for activated sludge using forward osmosis (FO). In this study, the municipal wastewater sludge was spiked with different nutrient concentrations to evaluate FO dewatering performance. The results showed that sludge concentration reached 21,511 and 28,500mg/L after 28h from initial sludge concentration of 3000 and 8000mg/L with flow rate of 150mL/min. Moreover, nutrient and organic compounds in sludge solution were also successfully removed (around 96% of NH4(+)-N, 98% of PO4(3-)-P and 99% of dissolved organic carbon (DOC)) due to steric effect of FO membrane and multi barrier layer of sludge forming on membrane surface. Furthermore, the analysis from Scanning Electron Microscopy & Energy Dispersive X-ray Spectroscopy (SEM-EDS) images recorded that FO membrane was fouled by cake layer of sludge in the active layer and NaCl in the support layer. PMID:23411452

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

2013-03-01

172

Macroinvertebrate community responses to a dewatering disturbance gradient in a restored stream  

NASA Astrophysics Data System (ADS)

Dewatering disturbances are common in aquatic systems and represent a relatively untapped field of disturbance ecology, yet studying dewatering events along gradients in non-dichotomous (i.e., wet/dry) terms is often difficult. Because many stream restorations can essentially be perceived as planned hydrologic manipulations, such systems can make ideal test-cases for understanding processes of hydrological disturbance. In this study we used an experimental drawdown in a 440 ha stream/wetland restoration site to assess aquatic macroinvertebrate community responses to dewatering and subsequent rewetting. The geomorphic nature of the site and the design of the restoration allowed dewatering to occur predictably along a gradient and decoupled the hydrologic response from any geomorphic (i.e., habitat heterogeneity) effects. In the absence of such heterogeneous habitat refugia, reach-scale wetted perimeter and depth conditions exerted a strong control on community structure. The community exhibited an incremental response to dewatering severity over the course of this disturbance, which was made manifest not as a change in community means but as an increase in community variability, or dispersion, at each site. The dewatering also affected inter-species abundance and distributional patterns, as dewatering and rewetting promoted alternate species groups with divergent habitat tolerances. Finally, our results indicate that rapid rewetting - analogous to a hurricane breaking a summer drought - may represent a recovery process rather than an additional disturbance and that such processes, even in newly restored systems, may be rapid.

Muehlbauer, J. D.; Doyle, M. W.; Bernhardt, E. S.

2010-12-01

173

Electro-dewatering of wastewater sludge: influence of the operating conditions and their interactions effects.  

PubMed

Electric field-assisted dewatering, also called electro-dewatering (EDW), is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. The application of these additional fields can be applied to either or both dewatering stages (filtration and/or compression), or as a pre-or post-treatment of the dewatering process. In this study, the performance of the EDW on wastewater sludge was investigated. Experiments were carried out on a laboratory filtration/compression cell, provided with electrodes, in order to apply an electrical field. The chosen operating conditions pressure (200-1200 kPa) and voltage (10-50 V) are sufficient to remove a significant proportion of the water that cannot be removed using mechanical dewatering technologies alone. A response surface methodology (RSM) was used to evaluate the effects of the processing parameters of EDW on (i) the final dry solids content, which is a fundamental dewatering parameter and an excellent indicator of the extent of EDW and (ii) the energy consumption calculated for each additional mass of water removed. A two-factor central composite design was used to establish the optimum conditions for the EDW of wastewater sludge. Experiments showed that the use of an electric field combined with mechanical compression requires less than 10 and 25% of the theoretical thermal drying energy for the low and moderate voltages cases, respectively. PMID:21453949

Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

2011-04-01

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 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

175

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

National Technical Information Service (NTIS)

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....

B. K. Parekh

1991-01-01

176

Electroacoustic Dewatering of Food and Other Suspensions: Phase 1, Final Report.  

National Technical Information Service (NTIS)

A research and development program is being conducted to demonstrate application of the Electroacoustic Dewatering (EAD) technology to food processing with the main goal of achieving significant energy savings. The Phase I of the two-phase program has bee...

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

1987-01-01

177

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

178

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

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1996-01-01

179

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

National Technical Information Service (NTIS)

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 portabl...

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

1998-01-01

180

Experimental Program for the Development of Peat Gasification. Interim Report No. 11. Solvent-Extraction Dewatering.  

National Technical Information Service (NTIS)

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 prope...

1982-01-01

181

Hydrate Process for Waste Water Treatment Plant Sludge Dewatering: Commercialization Assessment.  

National Technical Information Service (NTIS)

More attention is being paid to innovative technologies for sludge dewatering as larger proportions of wastewater treatment plant budgets are going toward the handling, processing, and disposing of sludge. One such process, the clathrate process, has sign...

1985-01-01

182

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

183

Challenge of mine dewatering to western water law and the New Mexico response  

SciTech Connect

Deep mining of uranium is currently taking place on a large scale in the western United States. One of the problems facing uranium mining companies is the removal of groundwater from mines. Dewatering is currently treated in a variety of ways by western states. Some of the problems that have arisen under these various state laws are examined. New dewatering legislation been enacted in New Mexico is examined and found to be innovative in creating devices new to prior appropriations laws. 157 references.

Stephenson, B.G. (Univ. of New Mexico, Albuquerque); Utton, A.E.

1980-01-01

184

Helminth eggs inactivation efficiency by faecal sludge dewatering and co-composting in tropical climates  

Microsoft Academic Search

This study investigates helminth eggs removal and inactivation efficiency in a treatment process combining faecal sludge (FS) dewatering and subsequent co-composting with organic solid waste as a function of windrow turning frequency. Fresh public toilet sludge and septage mixed at a 1:2 ratio were dewatered on a drying bed. Biosolids with initial loads of 25–83 helminth eggs\\/g total solids (TS)

Doulaye Koné; Olufunke Cofie; Christian Zurbrügg; Katharina Gallizzi; Daya Moser; Silke Drescher; Martin Strauss

2007-01-01

185

Combined method for simultaneously dewatering and reconstituting finely divided carbonaceous material  

DOEpatents

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

186

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

187

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

188

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

189

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

Microsoft Academic Search

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

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

1989-01-01

190

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

191

Disinfection and dewatering of wastewater solids by interstitial vapor generation.  

PubMed

Disinfection of wastewater solids (waste activated solids [WAS]) by interstitial vapor generation was investigated. In addition to the magnitude of disinfection, the amount of water removed and cost relative to traditional residuals disinfection processes was also examined. The process of interstitial vapor generation occurs as a result of the rapid heating of liquid in the interstices of the solid-liquid array. Intense heating causes boiling of the slurry liquid, resulting in an expanding vapor front that simultaneously dewaters the wastewater solids and contributes to the destruction of viable pathogenic microorganisms. Objectives of the study were threefold: (1) to validate disinfection of WAS using the interstitial vapor technique; (2) establish the degree of possible drying of the residuals using the techniques; and (3) establish the key operating variables for the process. Results showed a significant reduction in the most probable number of total coliforms and Escherichia coli (E. coli). Specifically, greater than four-log unit reductions were produced for both total coliform and E. coli bacteria. In addition to quantifying the reduction in bacteria, the percent solids were increased from an initial amount of 7.6% (mass basis) to a final solids content greater than 90% using optimal processing conditions. Cost comparisons were also conducted and shown to be quite favorable when compared with traditional disinfection methods such as lime addition. Because of the high level of E. coli reduction achieved, the process of interstitial vapor generation is shown to be capable of converting a class B biosolids into a class A pathogen reduced product. For example, an initial most probable number (MPN) of 1.2 x 10(6) E. coli bacteria were reduced to 19 at the extreme conditions of the process, well below the requirement of an MPN of 1000 for fecal coliform bacteria. Given its ability to disinfect and dewater wastewater solids, the interstitial vapor generation process was found to be a robust and beneficial technique to produce an environmental and publicly acceptable recyclable biosolids resource. PMID:16042114

Kramer, Timothy A; Hill, T Keith; Beckley, John

2004-01-01

192

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

193

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

194

Vibrating membrane filtration as improved technology for microalgae dewatering.  

PubMed

The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2?m) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. PMID:24561630

Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

2014-04-01

195

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

196

Settling and dewatering characteristics of granulated methane-oxidizing bacteria.  

PubMed

We evaluated the settling ability and dewaterability of granulated methane-oxidizing bacteria (GMOB) after granulation using a continuous-flow reactor. A comparative analysis on settling and dewatering characteristics due to changes in sludge retention time (SRT, 10, 15 and 20 days) during cultivation of GMOB was conducted. In assessing dewaterability, the specific resistance to filtration (SRF) of activated sludge and GMOB was found to be 8.21 x 10(13)-2.38 x 10(14) and 4.88 x 10(12) - 1.98 x 10(13) m/kg, respectively. It was confirmed that as SRT decreased, SRF of GMOB increased. In the case of bound extracellular polymeric substance (EPS), activated sludge registered 147.5 mg/g-VSS while GMOB exhibited 171-177.2 mg/g-VSS. In the case of extracellular polymeric substance soluble EPS in effluent, activated sludge measured 62 mg/L and GMOB had 17.4-21.4 mg/L. The particle size analysis showed that mean particle diameters of GMOB were 402, 369, and 350 microm, respectively, at SRTs of 20, 15 and 10 days. In addition, it was found that GMOB had a larger mean particle diameter and exhibited much better settleability and dewaterability than activated sludge did. PMID:23596947

Ahn, Kwang Ho; Kim, Kwang Soo; Kang, Sung Won; Um, Chul Yong; Lee, Won Tae; Ko, Kwang Baik

2013-02-01

197

Effects of surface chemical and electrochemical factors on the dewatering characteristics of fine particle slurry.  

PubMed

Coal suspension was employed in vacuum filtration process to observe the dewatering characteristics of fine particle slurry. Generally, as the size of coal particle decreased, the specific resistance was increased and dewatering efficiency was reduced. Slurries containing the particles with a broad size range had a higher compressibility and could not filter easily if modified process was not applied. This study also investigated the effects of an anionic and a cationic surfactants on filterability by examining the surface property of coal particles. Dewatering was observed to be more efficient when cationic surfactant was used. To improve dewatering rate and to reduce the final moisture content of slurry, electrodewatering combined with vacuum filtration was applied. The effects of some different variables were examined, such as the type of surfactants, electrode (arrangements and materials), and the electrical parameters (voltage and current). By application of electrodewatering, dewatering efficiency was found to be enhanced compared to conventional vacuum filtration. The specific resistance was represented to be 0.3815 at 0 V, whereas it was shown to be 0.2113 and 0.1631 at 20 V under direct current and alternative current, respectively. PMID:15332676

Kuh, Sung-Eun; Kim, Dong-Su

2004-01-01

198

Co-conditioning and dewatering of chemical sludge and waste activated sludge.  

PubMed

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. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed. PMID:11228978

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

2001-03-01

199

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

200

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

201

Development and testing of a novel mechanical device for dewatering peat. Final report, September 22, 1983December 31, 1985  

Microsoft Academic Search

The Internal Rotary Compression (IRC) system concept tested in this program for mechanical dewatering of peat was suggested by Anderson Metal Industries, Inc. In this system, one roll rotates inside another roll, and simultaneously applies compression and shear forces to the peat between nonporous roll surfaces. The IRC press improves peat dewatering, is small in size because rolling surfaces are

F. S. Lau; M. J. Roberts; M. C. Mensinger; D. V. Punwani

1986-01-01

202

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

203

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

204

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

205

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

206

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.

207

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

208

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

SciTech Connect

Battelle, in cooperation with the Electric Power Research Institute (EPRI) CQ, Inc., Ashbrook-Simon-Hartley (ASH), 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. The project has the following objectives: To validate the expected technical feasibility and energy conservation/economic benefits of the EAD process as applied to fine ({minus}100 mesh) and ultrafine ({minus}325 mesh) coal; and to obtain data from a continuous, process research unit (PRU) in order to conduct a reliable economic analysis and to design commercial EAD filters as well as to promote adaptation of the process by the coal preparation industry. Progress is reported. 2 figs., 4 tabs.

Kim, B.C.; Criner, C.L.; Wu, H.; Senapati, N.; Chauhan, S.P.

1990-08-10

209

Development of the Electroacoustic Dewatering (EAD) process for fine/ultrafine coal  

SciTech Connect

Battelle, in cooperation with the Electric Power Research Institute (EPRI), CQ, Inc., Ashbrook-Simon-Hartley (ASH), 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 adaption of synergistic effects of electric and acoustic fields to commercial coal dewatering systems, such as belt filter presses include: validation of the expected technical feasibility and energy conservation/economic benefits of the EAD process as applied to fine (-100 mesh) and ultrafine (-325 mesh) coal; and data acquisition from a continuous, process research unit (PRU) in order to conduct a reliable economic analysis and to design commercial EAD filters as well as to promote adaptation of the process by the coal preparation industry.

Jirjis, B.F.; Senapati, N.; Menton, R.; Hsieh, P.; Chauhan, S.P. (Battelle, Columbus, OH (USA)); Chiang, S.H.; Cheng, Y.S. (Pittsburgh Univ., PA (USA). Dept. of Chemical Engineering)

1990-03-13

210

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

SciTech Connect

Battelle is undertaking engineering development of 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. The Battelle project for demonstrating the potential for commercial application of the EAD process for coal has the following objectives: to validate the expected technical feasibility and energy conservation/economic benefits of the EAD process as applied to fine ({minus}100 mesh) and ultrafine ({minus}325 mesh) coal; and to obtain data from a continuous, process research unit (PRU) in order to conduct a reliable economic analysis and to design commercial EAD filters as well as to promote adaptation of the process by the coal preparation industry. Progress is discussed. 4 figs.

Kim, B.C.; Criner, C.L.; Wu, H.; Menton, R.; Senapati, N.; Chauhan, S.P.

1990-11-09

211

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

212

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

213

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

214

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

215

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

216

Compression dewatering of municipal activated sludge: effects of salt and pH.  

PubMed

Even after mechanical dewatering, activated sludge contains a large amount of water. Due to its composition and biological nature this material is usually highly compressible and known to be difficult to dewater. In the present work, two treatments (salt addition and pH modification) are proposed to highlight some aspects which could explain the poor dewaterability of activated sludge. Dewatering tests are carried out in a pressure-driven device in order to well examine both, filtration and compression stages. Physico-chemical parameters, such as surface charge, hydrophobicity, extracellular polymeric substances (EPS) content and filtrate turbidity are measured on the tested sludge, for a better analysis of dewatering results. The dewatering ability of the sludge is widely linked to the cohesion of the flocculated matrix and the presence of fine particles. Both treatments alter the flocculated matrix and release fine particles. The release of fine particles tends to clog both, the filter cake and the filter medium. Consequently, the filtration rate decreases due to higher resistances to the flow. On another hand, the polymeric matrix breakdown enables to release some water trapped within the floc to the bulk liquid phase and thus facilitates its removal, which tends to decrease the moisture content of the filter-cake. It also impacts the compression dewatering step. The more destroyed structures lead to less elastic cakes and thus a slower primary consolidation stage. At the opposite, the mobility of the broken aggregates within the filter-cake does not seem to be improved by size reduction (the kinetics of the secondary consolidation stage are not significantly modified). PMID:22735341

Raynaud, Mickael; Vaxelaire, Jean; Olivier, Jérémy; Dieudé-Fauvel, Emilie; Baudez, Jean-Christophe

2012-09-15

217

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

218

Development of the Screen Bowl Centrifuge for the dewatering of coal fines  

SciTech Connect

Dewatering of the fine clean coal fraction. - 28 mesh (595 microns) represents one of the most difficult and costly separations in typical plant circuits. Since 1969, the Screen Bowl Centrifuge has offered an economical alternative to filtration/thermal dryer combinations. The performance of Screen Bowl Centrifuges has been continuously modified and improved to dewater not only coarser coals, but also today's variety of ultrafine material. Actual test comparisons with alternative methods show the Screen Bowl Centrifuge to be most cost effective and efficient when all factors are considered.

Policow, N.D.; Orphanos, J.S.

1982-09-01

219

Considerations for application of electrical submersible pumps for underground coal mine dewatering--  

SciTech Connect

This paper discusses how at mining depths beyond 800 ft. electrical submersible pumps become an economic alternative for coal mine dewatering. Pump configurations differ from freshwater or petroleum applications. Coal mines are regulated by the Mining Safety and Health Administration. Power supplies are resistance grounded.

Nave, M.L. (Consolidated Coal Company, Pittsburgh PA (US))

1989-09-01

220

Considerations for application of electrical submersible pumps for underground coal mine dewatering  

Microsoft Academic Search

At mining depths beyond 800 ft., electrical submersible pumps become an economic alternative for coal mine dewatering. Pump configurations differ from those used for freshwater or petroleum applications. Controls are implemented by a combination of commercial and custom techniques. Pump configurations, code requirements, and pump controls are discussed. It is stressed that pump reliability is affected by downhole conditions, logical

M. L. Nave

1989-01-01

221

Considerations for application of electrical submersible pumps for underground coal mine dewatering  

Microsoft Academic Search

Deep coal seams require mine dewatering pumps of high capacity, high head, and high reliability. Mining ESPs (electric submersible pumps) are an adaptation of fresh-water or oil-well ESPs. To pump from a horizontal coal seam, special pump configurations are required. Downhole conditions are severe. Mine water is acidic and carries suspended solids. Electrics on mining ESPs are regulated by federal

M. L. Nave

1988-01-01

222

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

Microsoft Academic Search

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

1996-01-01

223

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

Microsoft Academic Search

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

J. W. Wilson; R. Q. Honaker

1994-01-01

224

Micro-properties of coal aggregates: Implications on hyperbaric filtration performance for coal dewatering  

Microsoft Academic Search

The recovery of ultrafine coal can be enhanced significantly by flocculating the particles prior to dewatering. It is thus crucial to be able to quantify the effects of aggregated particles on the separation efficiency, of which they are still not fully understood. This study focused on the relationship between the micro-properties (size, structure, and strength) of flocculated coal particles and

C. Selomulya; J. Y. H. Liao; G. Bickert; R. Amal

2006-01-01

225

Advanced Dewatering Systems Development. Phase II Final Report Period July 14, 2000 to July 14, 2008.  

National Technical Information Service (NTIS)

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 c...

G. H. Luttrell R. H. Yoon

2008-01-01

226

Effect of hydrophobic group on flocculation properties and dewatering efficiency of cationic acrylamide copolymers  

Microsoft Academic Search

Three kinds of hydrophobically modified copolymers of acrylamide with 3-acrylamido-2-hydroxypropyltrialkylammonium chloride were prepared, in which alkyls were ethyl, butyl and octyl, respectively. The conformations of the hydrophobically modified copolymers were studied using TEM micrograph. The flocculation performances and the dewatering efficiencies were investigated. The results showed that the hydrophobic group could enhance the flocculation properties. The longer the hydrophobic alkyl

Haijing Ren; Wenna Chen; Yunfei Zheng; Zhaokun Luan

2007-01-01

227

Increasing cake solids of cellulosic sludge through enzyme-assisted dewatering  

Microsoft Academic Search

Brief treatment of wood pulp fibers or cellulosic sludge with cellulase enzymes ruptures the fibers at the kinked regions. Dewatering these fibers with a belt press simulator leads to higher cake solids because of better cake consolidation with the shorter fibers. The void volume of the cake is reduced. A three to six percentage point increase in cake solids is

Jian Lu; Swati Rao; Tuan Le; Sandeep Mora; Sujit Banerjee

2011-01-01

228

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

PubMed

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

Wett, B; Demattio, M; Becker, W

2005-01-01

229

Dewatering ofrefined, bleached hardwood kraft pulp by gravity, vacuum, and centrifugation with applied pressure  

Microsoft Academic Search

Three types ofdewatering tests wereperformed with refined, bleached hardwood kraft suspensions. A modified water retention value (lvJWRV) test was used, with pressure applied to damp plugs offibers during their centrifugation. Refining levels and dry­ ing conditions had dramatic and consistent effects on dewatering rates by gravity (freeness tests), with the application ofvacuum, and also the MWRV tests. Ef­ fects ofdrying

Mark Panczyk

230

Hydrogasification PDU studies on Florida peat and peat dewatered by various methods  

SciTech Connect

In this program, hydrogasification tests are being conducted in two separate tasks. The objective of Task 1 is to study the gasification characteristics of peats from Florida and Alaska. The objective of Task 2 is to determine the effects of dewatering methodologies on the gasification characteristics of peat. Peats dewatered by three methods have been selected for testing in this task. These are: North Carolina peat harvested by the sod peat method, Minnesota peat dewatered in a sulzer belt press and thermally dried at approx. 300/sup 0/F in a Sulzer fluidized-bed dryer, and Minnesota peat dewatered in a Sulzer belt press and thermally dried in a tray dryer at 250/sup 0/F. To date a total of four hydrogasification tests have been conducted with a reed sedge peat from Florida (Seffner, Florida) completing the planned tests. The tests were conducted with hydrogen, steam and hydrogen, and hydrogen and nitrogen mixtures, at a pressure of 250 psia, and at maximum coil temperatures ranging from 1080/sup 0/ to 1510/sup 0/F. The operating conditions and results of these tests are summarized in Table 1. A typical chemical analysis of the Florida peat is compared with that of a Minnesota, North Carolina, and a Maine peat in Table 2. The Florida peat had a calorific value similar to that of the Minnesota peat. Its ash content was higher than that of the others, but its oxygen content was lower.

Mensinger, M.C.; Lau, F.S.; Punwani, D.V.

1982-01-01

231

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

232

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

233

Co-conditioning and dewatering of alum sludge and waste activated sludge.  

PubMed

Co-conditioning and dewatering behaviors of alum sludge and waste activated sludge were investigated. Two different sludges were mixed at various ratios (2:1; 1:1; 1:2; 1:4) for study. Capillary suction time (CST) and specific resistance to filtration (SRF) were utilized to assess sludge dewaterability. Relatively speaking, waste activated sludge, though of higher solid content, was more difficult to be dewatered than alum sludge. It was found that sludge dewaterability and settlability became better with increasing fraction of alum sludge in the mixed sludge. Dosage required of the cationic polyelectrolyte (KP-201C) for dewatering was reduced as well. It is proposed that alum sludge acts as skeleton builder in the mixed sludge, and renders the mixed sludge more incompressible which is beneficial for sludge dewatering. Implications of the results of the study to the sludge management plan for Taipei City that generates both alum sludge and waste activated sludge at significant amount are also discussed. The current sludge treatment and disposal plan in Metropolitan Taipei could be made more cost-effective. PMID:15580993

Lai, J Y; Liu, J C

2004-01-01

234

Dewatering Sewage Sludge by Electro-Osmosis. Part II. Scale-Up Data.  

National Technical Information Service (NTIS)

A project scale rig for the electro-osmotic dewatering of sewage has been constructed. The rig, based on a moving belt concept, has been shown to be capable of continuous operation. A sewage cake in the region of 24% has been achieved, together with an ef...

D. Ellis J. G. Sunderland

1977-01-01

235

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

Microsoft Academic Search

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

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

1998-01-01

236

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

237

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

238

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

239

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...

240

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

241

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

242

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

243

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

244

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

245

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

246

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

247

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

248

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 ...

249

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

250

Influence of nanoparticles on the polymer-conditioned dewatering of wastewater sludges.  

PubMed

The effect of using small-scale, high surface area, nanoparticles to supplement polymer-conditioned wastewater sludge dewatering was investigated. Aerobically digested sludge and waste activated sludge sourced from the Hunter Valley, NSW, Australia, were tested with titanium dioxide nanoparticles. The sludge samples were dosed with the nanoparticles in an attempt to adsorb a component of the charged biopolymer surfactants present naturally in sludge. The sludge was conditioned with a cationic polymer. The dewatering characteristics were assessed by measuring the specific resistance to filtration through a modified time-to-filter testing apparatus. The solids content of the dosed samples was determined by a mass balance and compared to the original solids content in the activated sludge. Test results indicated that nanoparticle addition modified the structure of the sludge and provided benefits in terms of the dewatering rate. The samples dosed with nanoparticles exhibited faster water removal, indicating a more permeable filter cake and hence more permeable sludge. A concentration of 2-4% nanoparticles was required to achieve a noticeable benefit. As a comparison, the sludge samples were also tested with a larger particle size, powdered activated carbon (PAC). It was found that the PAC did provide some minor benefits to sludge dewatering but was outperformed by the nanoparticles. The solids content of the final sludge was increased by a maximum of up to 0.6%. The impact of the order sequence of particles and polymer was also investigated. It was found that nanoparticles added before polymer addition provided the best dewatering performance. This outcome was consistent with current theories and previous research through the literature. An economic analysis was undertaken to confirm the viability of the technology for implementation at a full-scale plant. It was found that, currently, this technology is unlikely to be favourable unless the nanoparticles can be sourced for a low cost. PMID:23656957

Boyle, N J; Evans, G M

2013-01-01

251

Evaluation of hyperbaric filtration for fine coal dewatering. Sixth quarterly technical progress report, 1 January--31 March 1994.  

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1994-01-01

252

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

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1996-01-01

253

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

National Technical Information Service (NTIS)

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 c...

B. K. Parekh J. W. Leonard R. Hogg A. Fonesca

1995-01-01

254

Evaluation of hyperbaric filtration for fine coal dewatering. Fourth quarterly technical progress report: June 1, 1993--September 30, 1993.  

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1993-01-01

255

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

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1995-01-01

256

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

National Technical Information Service (NTIS)

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 co...

B. K. Parekh R. Hogg A. Fonseca

1993-01-01

257

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

National Technical Information Service (NTIS)

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 co...

B. K. Parekh J. W. Leonard R. Hogg A. Fonseca

1995-01-01

258

Ultra scale-down device to predict dewatering levels of solids recovered in a continuous scroll decanter centrifuge.  

PubMed

During centrifugation operation, the major challenge in the recovery of extracellular proteins is the removal of the maximum liquid entrapped within the spaces between the settled solids-dewatering level. The ability of the scroll decanter centrifuge (SDC) to process continuously large amounts of feed material with high concentration of solids without the need for resuspension of feeds, and also to achieve relatively high dewatering, could be of great benefit for future use in the biopharmaceutical industry. However, for reliable prediction of dewatering in such a centrifuge, tests using the same kind of equipment at pilot-scale are required, which are time consuming and costly. To alleviate the need of pilot-scale trials, a novel USD device, with reduced amounts of feed (2 mL) and to be used in the laboratory, was developed to predict the dewatering levels of a SDC. To verify USD device, dewatering levels achieved were plotted against equivalent compression (Gtcomp ) and decanting (Gtdec ) times, obtained from scroll rates and feed flow rates operated at pilot-scale, respectively. The USD device was able to successfully match dewatering trends of the pilot-scale as a function of both Gtcomp and Gtdec , particularly for high cell density feeds, hence accounting for all key variables that influenced dewatering in a SDC. In addition, it accurately mimicked the maximum dewatering performance of the pilot-scale equipment. Therefore the USD device has the potential to be a useful tool at early stages of process development to gather performance data in the laboratory thus minimizing lengthy and costly runs with pilot-scale SDC. PMID:24124159

Lopes, A G; Keshavarz-Moore, E

2013-01-01

259

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

260

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

SciTech Connect

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

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

1991-10-31

261

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

SciTech Connect

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

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

1991-10-31

262

Development of the Electroacoustic Dewatering (EAD) process for fine/ultrafine coal  

SciTech Connect

This report describes an advanced process, called Electroacoustic Dewatering (EAD), which capitalizes on the adaptation of synergistic effects of electric and acoustic fields to commercial coal dewatering systems, such as belt filter presses. Objectives are: (1) to validate the expected technical feasibility and energy conservation/economic benefits of the EAD process as applied to fine ({minus}100 mesh) and ultrafine ({minus}325 mesh) coal; and (2) to obtain data from a continuous, process research unit (PRU) in order to conduct a reliable economic analysis and to design commercial EAD filters as well as to promote adaptation of the process by the coal preparation industry. During this quarter, our efforts were focused on material selection, acquisition, and characterization and on laboratory EAD tests. 8 figs., 6 tabs.

Muralidhara, H.S.; Jirjis, B.F.; Senapati, N.; Menton, R.; Hsieh, P.; Chiang, S.H.; Cheng, Y.S.; Chauhan, S.P. (Battelle Memorial Inst., Columbus, OH (USA); Pittsburgh Univ., PA (USA). Dept. of Chemical Engineering; Battelle Memorial Inst., Columbus, OH (USA))

1989-10-30

263

Coal-water interaction and preparation of dewatered ultrafine clean coal  

SciTech Connect

The mandate of this project was to understand the mechanism responsible for coal-water interactions and to understand why coal holds water. In addition, we were to develop a bench-scale dewatering technique, based on heavy crude oil (< 20{degrees} API) treatments. Consequently, we undertook electron paramagnetic resonance (EPR), in situ desorption kinetics via Fourier transform infrared (ISDK-FTIR), specific heat, and in situ air-drying measurements on Hagel lignite coal, Illinois No. 2 bituminous coal, and oxidized Illinois No. 2 bituminous coal to understand how water interacts with coal. Attempts were also made to dewater Homer City bituminous coal cake and Illinois No. 2 coal-water slurry by treating these coals with (1) n-pentane, (2) petrolene {plus} n-pentane, (3) asphaltene {plus} benzene, (4) crude oil, and (5) crude oil {plus} asphaltene {plus} benzene. 34 refs., 34 figs., 11 tabs.

Malhotra, V.M.; Zitter, R.N.

1990-03-01

264

Development of the Electroacoustic Dewatering (EAD) process for fine/ultrafine coal  

SciTech Connect

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. The Battelle project for demonstrating the potential for commercial application of the EAD process for coal has the following objectives: to validate the expected technical feasibility and energy conservation/economic benefits of the EAD process as applied to fine (-100 mesh) and ultrafine (-325 mesh) coal; and to obtain data from a continuous, process research unit (PRU) in order to conduct a reliable economic analysis and to design commercial EAD filters as well as to promote adaptation of the process by the coal preparation industry. During this quarter, efforts were directed towards completion of PRU operation. The paper describes results from field testing on miners 325 mesh Upper Freeport coal and discusses the effects of experimental factors on final cake solids and on delta solids and linear regression models. 4 figs., 4 tabs.

Kim, B.C.; Criner, C.L.; Senapati, N.; Menton, R.; Chou, Y.L.; Chauhan, S.P.

1991-01-25

265

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

SciTech Connect

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

Parekh, B.K.

1991-12-31

266

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

267

Helminth eggs inactivation efficiency by faecal sludge dewatering and co-composting in tropical climates.  

PubMed

This study investigates helminth eggs removal and inactivation efficiency in a treatment process combining faecal sludge (FS) dewatering and subsequent co-composting with organic solid waste as a function of windrow turning frequency. Fresh public toilet sludge and septage mixed at a 1:2 ratio were dewatered on a drying bed. Biosolids with initial loads of 25-83 helminth eggs/g total solids (TS) were mixed with solid waste as bulking material for co-composting at a 1:2 volume ratio. Two replicate sets of compost heaps were mounted in parallel and turned at different frequencies during the active composting period: (i) once every 3 days and (ii) once every 10 days. Turning frequency had no effect on helminth eggs removal efficiency. In both setups, helminth eggs were reduced to <1 viable egg/g TS, thereby complying with the WHO guidelines 2006 for the safe reuse of FS. PMID:17624391

Koné, Doulaye; Cofie, Olufunke; Zurbrügg, Christian; Gallizzi, Katharina; Moser, Daya; Drescher, Silke; Strauss, Martin

2007-11-01

268

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

SciTech Connect

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

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

1992-08-01

269

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

PubMed

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

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

270

Coal-water interaction and preparation of dewatered ultrafine clean coal  

Microsoft Academic Search

The mandate of this project was to understand the mechanism responsible for coal-water interactions and to understand why coal holds water. In addition, we were to develop a bench-scale dewatering technique, based on heavy crude oil (< 20° API) treatments. Consequently, we undertook electron paramagnetic resonance (EPR), in situ desorption kinetics via Fourier transform infrared (ISDK-FTIR), specific heat, and in

V. M. Malhotra; R. N. Zitter

1990-01-01

271

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

Microsoft Academic Search

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.,

Parekh

1991-01-01

272

Numerical simulation of dewatering thick unconsolidated aquifers for safety of underground coal mining  

Microsoft Academic Search

With an increase of mining the upper limits under unconsolidated aquifers, dewatering of the bottom aquifer of the Quaternary system has become a major method to avoid water and sand inrushes. In the 8th District of the Taiping Coal Mine in south-western Shandong province, the bottom aquifer of the Quaternary system is moderate to excellent in water-yielding capacity. The base

Yuan HANG; Gai-ling ZHANG; Guo-yong YANG

2009-01-01

273

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

274

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

PubMed

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

Komilis, Dimitrios; Evangelou, Alexandros; Voudrias, Evangelos

2011-09-01

275

Particulates in hydrometallurgy: Part II. Dewatering behavior of unflocculated laterite acid leach residues  

Microsoft Academic Search

The effects of ore type and leaching conditions (e.g., temperature and solid\\/liquid ratio) on the settling behavior of laterite acid leach residues were investigated. Settling\\u000a rate, supernatant turbidity, and filtrability of the slurry were used in evaluating the settling behavior. The slurries showed\\u000a three different regimes of sedimentation, involving free, hindered, and compression settling behavior. An improvement in the\\u000a dewatering

A. Briceno; K. Osseo-Asare

1995-01-01

276

Gas cleaning test using a ceramet filter in fluidized bed dewatering and calcining waste solutions  

Microsoft Academic Search

This article presents test results* of an experimental 26 m 2 effective surface ceramet filter. These tests lasted for 1000 h at a dewatering and calcination fluidized bed unit for nitrate--phospha te solutions. Solution composition was: 125 g\\/liter NaNO 3, 240 g\\/liter Al(NO3) 3 , 120 gaiter H3PO 4, and 90 g\\/liter residue. Filter construction is shown in Fig. 1.

N. S. Lokotanov; O. A. Nosyrev

1975-01-01

277

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

Microsoft Academic Search

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

Jonas Addai-Mensah; John Ralston

2004-01-01

278

Optimising the dewatering behaviour of clay tailings through interfacial chemistry, orthokinetic flocculation and controlled shear  

Microsoft Academic Search

The effect of shear on dewatering behaviour and particle interactions of Na-exchanged smectite and kaolinite clay dispersions has been investigated at pH 7.5, using hydrolysable Ca(II) and Mn(II) ions as coagulants and high molecular weight anionic and non-ionic polyacrylamide (PAM A and PAM N, respectively) and polyethylene oxide (PEO) flocculants. Metal ion addition enhanced the flocculation performance by dramatically reducing

A. J. McFarlane; K. E. Bremmell; J. Addai-Mensah

2005-01-01

279

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

280

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

281

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

282

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

283

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

284

Shear sensitivity of digested sludge: comparison of methods and application in conditioning and dewatering.  

PubMed

Shear sensitivity of digested sludge was evaluated by two methods: a CST shear test and a strain sweep rheological method of measuring yield stress. Sludge pretreatment by an enzyme formulation was used to alter the sludge's response to shear and, potentially, to improve dewaterability. Also varied were the polymer conditioning dose and the amount of shear applied by mixing. A bench-scale device was then used to simulate dewatering by belt press in order to assess the CST shear tests and the rheological test. CST-based shear tests showed that the optimum chemical conditioner doses with low shear levels became sub-optimal with increasing mixing times. For all three polymer conditioners, longer shear times increased the dose requirements. When the polymer dose was held constant, and the extent of mixing varied, the CST test was a poor indicator of effects on dewaterability. The benefits of enzyme treatment, apparent by actual dewatering, were not predicted by the CST results. In contrast, yield stress values were significantly correlated with cake solids values, and inversely correlated with filtrate solids. Yield stress is not adequate by itself to predict final cake solids after dewatering, because enzyme pretreatment gave higher solids concentrations when both shear extent and initial yield stress were held constant. PMID:19665749

Dentel, Steven K; Dursun, Derya

2009-10-01

285

[Relationship of evaluation indexes of sludge dewatering performance under different conditioning programs].  

PubMed

Performances of different sludge conditioners are difficult to evaluate due to the use of various evaluation indexes. Taking several traditional sludge conditioners, e.g. PAM, FeCl3 and inorganic composite conditioners as examples and five evaluation indexes include specific resistance to filtration (SRF), capillary suction time (CST), sludge settling performance, water content of sludge cake and dewatering efficiency, were investigated respectively in order to study the correlation among those indexes. The results indicate a significant positive linear correlation between SRF and CST (R2 values are 0.96 and 0.93, respectively) after adding different types of conditioners or different amount of conditioners. While they can precisely reflect plate and frame filter press efficiency, but they fail to predict the effects of centrifugal dewatering. Sludge settling performance presents the similar tendencies with SRF and CST. Since there is only limited correlation rather than strict correspondence between water content of sludge cake and dewatering efficiency. Thus, both factors should be considered synthetically in optimizing dosage performances. PMID:22295640

Liu, Huan; Yang, Jia-Kuan; Shi, Ya-Fei; Li, Ye; He, Shu

2011-11-01

286

Emplacement and dewatering of the world's largest exposed sand injectite complex  

NASA Astrophysics Data System (ADS)

Sandstone injectites form by up or down-section flow of a mobilized sand slurry through fractures in overlying rock. They act as reservoirs and high-permeability conduits through lower permeability rock in hydrocarbon systems. The Yellow Bank Creek Complex, Santa Cruz County, California is the largest known exposure of a sandstone injectite in the world. The complex contains granular textures that record processes of sand slurry flow, multiple pore fluids, and dewatering after emplacement. The injection was initially mobilized from a source containing both water and hydrocarbons. The water-sand slurry reached emplacement depth first, due to lower fluid viscosity. As the sand slurry emplaced, the transition from slurry flow to pore water percolation occurred. This transition resulted in preferred flow channels ˜6 mm wide in which sand grains were weakly aligned (laminae). The hydrocarbon-sand slurry intruded the dewatering sands and locally deformed the laminae. Compaction of the injectite deposit and pore fluid escape caused spaced compaction bands and dewatering pipes which created convolutions of the laminae. The hydrocarbon-rich sand slurry is preserved today as dolomite-cemented sand with oil inclusions. The laminae in this injectite are easily detected due to preferential iron oxide-cementation of the well-aligned sand laminae, and lack of cement in the alternating laminae. Subtle textures like these may develop during sand flow and be present but difficult to detect in other settings. They may explain permeability anisotropy in other sand deposits.

Sherry, Timothy J.; Rowe, Christie D.; Kirkpatrick, James D.; Brodsky, Emily E.

2012-08-01

287

Demonstration of FBRM as process analytical technology tool for dewatering processes via CST correlation.  

PubMed

The current challenges associated with the design and operation of net-energy positive wastewater treatment plants demand sophisticated approaches for the monitoring of polymer-induced flocculation. In anaerobic digestion (AD) processes, the dewaterability of the sludge is typically assessed from off-line lab-bench tests - the capillary suction time (CST) test is one of the most common. Focused beam reflectance measurement (FBRM) is a promising technique for real-time monitoring of critical performance attributes in large scale processes and is ideally suited for dewatering applications. The flocculation performance of twenty-four cationic polymers, that spanned a range of polymer size and charge properties, was measured using both the FBRM and CST tests. Analysis of the data revealed a decreasing monotonic trend; the samples that had the highest percent removal of particles less than 50 microns in size as determined by FBRM had the lowest CST values. A subset of the best performing polymers was used to evaluate the effects of dosage amount and digestate sources on dewatering performance. The results from this work show that FBRM is a powerful tool that can be used for optimization and on-line monitoring of dewatering processes. PMID:24751547

Cobbledick, Jeffrey; Nguyen, Alexander; Latulippe, David R

2014-07-01

288

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

289

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

290

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

291

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

SciTech Connect

The primary goal of the current coal preparation research is to reduce the ash and sulfur content from coal, using fine grinding and various coal cleaning processes to separate finely disseminated mineral matter and pyrite from coal. Small coal particles are produced by the grinding operation, thus the ultrafine coal becomes very difficult to dewater. In addition, the ultrafine coal also creates problems during its transportation, storage and handling at utility plants. The current research is seeking to combine ultrafine coal dewatering and briquetting processes into a single stage operation, using hydrophobic binders as coal dewatering and binding reagents with the help of a compaction device. From previous tests, it has been found that coal pellets with a moisture content of less than 15% and good wear and water resistance can be successfully fabricated at pressures of less than 6,000 psi using a lab scale ram extruder. The primary objective of the research described in this quarter has been to extend the lab scale ultrafine coal dewatering and briquetting process into a pilot scale operation, based on the test data obtained from earlier research. A standard roller briquetting machine was used to dewater fine coal-binder mixtures during the briquetting process. The operating parameters, including moisture content of feed, feed rate, and roller speed, were evaluated on the basis of the performance of the briquettes. Briquettes fabricated at rates of up to 108 pellets per minute exhibited satisfactory water and wear resistance, i.e., less than 7.5% cured moisture and less than 8.3% weight loss after 6 min. of tumbling. Also, coal-binder samples with moisture contents of 40 percent have been successfully dewatered and briquetted. Briquetting of fine coal was possible under current feeding conditions, however, a better feeding system must be designed to further improve the quality of dewatered coal briquettes.

Wilson, J.W.; Ding, Y. [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

1995-12-31

292

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

293

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

294

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

295

How can sludge dewatering devices be assessed? Development of a new DSS and its application to real case studies.  

PubMed

A key issue in biological Waste Water Treatment Plants (WWTPs) operation is represented by the sludge management. Mechanical dewatering is a crucial stage for sludge volume reduction; though, being a costly operation, its optimization is required. We developed an original experimental methodology to evaluate the technical (dewatering efficiency) and financial (total treatment costs) performance of dewatering devices, which might be used as a DSS (Decision Support System) for WWTP managers. This tool was then applied to two real case studies for comparing, respectively, three industrial size centrifuges, and two different operation modes of the same machine (fixed installation vs. outsourcing service). In both the cases, the best option was identified, based jointly on economic and (site-specific) technical evaluations. PMID:24603031

Bertanza, Giorgio; Papa, Matteo; Canato, Matteo; Collivignarelli, Maria Cristina; Pedrazzani, Roberta

2014-05-01

296

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

SciTech Connect

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

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

1992-12-31

297

Dewatering studies of fine clean coal. Technical report, March 1, 1992--May 31, 1992  

SciTech Connect

Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, due to high surface area of particles the amount of water associated with clean coal is high. Economic removal of water to 20 percent or lower moisture level from the clean coal froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effect of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. The studies have identified a combination of metal ions and surfactant found to be effective in providing a 22 percent moisture filter cake. During the third quarter, efforts were made to understand reagent adsorption mechanism. Adsorption studies indicated that the presence of metal ions enhanced adsorption of surfactant. It appears that metal ions induced floc formation at pH {approximately}7.0, which are hydrophilic in nature, however addition of surfactant restores the hydrophobicity. Organic polymers along with metal ions were found to be effective in dewatering of fine coal. Continuous filtration tests conducted using a drum filter provided a filter cake containing 24 percent moisture. Additional studies on mechanism of adsorption and continuous filtration using AC Electro-Coagulation will be conducted in the next quarter.

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

1992-10-01

298

Effects of cationic polyacrylamide characteristics on sewage sludge dewatering and moisture evaporation.  

PubMed

The effects of the molecular weight (MW) and charge density (CD) of cationic polyacrylamide (CPAM) on sludge dewatering and moisture evaporation were investigated in this study. Results indicated that in sludge conditioning, the optimum dosages were 10, 6, 6, 4, and 4 mg g(-1) CPAM with 5 million MW and 20% CD, 5 million MW and 40% CD, 3 million MW and 40% CD, 8 million MW and 40% CD, and 5 million MW and 60% CD, respectively. The optimum dosage of CPAM was negatively correlated with its CD or MW if the CD or MW of CPAM was above 20% or 5 million. In the centrifugal dewatering of sludge, the moisture content in the conditioned sludge gradually decreased with the extension of centrifugation time, and the economical centrifugal force was 400×g. The moisture evaporation rates of the conditioned sludge were closely related to sludge dewaterability, which was in turn significantly correlated either positively with the solid content of sludge particles that were >2 mm in size or negatively with that of particles measuring 1 mm to 2 mm in diameter. During treatment, sludge moisture content was reduced from 80% to 20% by evaporation, and the moisture evaporation rates were 1.35, 1.49, 1.62, and 2.24 times faster in the sludge conditioned using 4 mg g(-1) CPAM with 5 million MW and 60% CD than in the sludge conditioned using 4 mg g(-1) CPAM with 8 million MW and 40% CD, 6 mg g(-1) CPAM with 5 million MW and 40% CD, 6 mg g(-1) CPAM with 3 million MW and 40% CD, and 10 mg g(-1) CPAM with 5 million MW and 20% CD, respectively. Hence, the CPAM with 5 million MW and 60% CD was ideal for sludge dewatering. PMID:24878582

Zhou, Jun; Liu, Fenwu; Pan, Chengyi

2014-01-01

299

Effects of Cationic Polyacrylamide Characteristics on Sewage Sludge Dewatering and Moisture Evaporation  

PubMed Central

The effects of the molecular weight (MW) and charge density (CD) of cationic polyacrylamide (CPAM) on sludge dewatering and moisture evaporation were investigated in this study. Results indicated that in sludge conditioning, the optimum dosages were 10, 6, 6, 4, and 4 mg g?1 CPAM with 5 million MW and 20% CD, 5 million MW and 40% CD, 3 million MW and 40% CD, 8 million MW and 40% CD, and 5 million MW and 60% CD, respectively. The optimum dosage of CPAM was negatively correlated with its CD or MW if the CD or MW of CPAM was above 20% or 5 million. In the centrifugal dewatering of sludge, the moisture content in the conditioned sludge gradually decreased with the extension of centrifugation time, and the economical centrifugal force was 400×g. The moisture evaporation rates of the conditioned sludge were closely related to sludge dewaterability, which was in turn significantly correlated either positively with the solid content of sludge particles that were >2 mm in size or negatively with that of particles measuring 1 mm to 2 mm in diameter. During treatment, sludge moisture content was reduced from 80% to 20% by evaporation, and the moisture evaporation rates were 1.35, 1.49, 1.62, and 2.24 times faster in the sludge conditioned using 4 mg g?1 CPAM with 5 million MW and 60% CD than in the sludge conditioned using 4 mg g?1 CPAM with 8 million MW and 40% CD, 6 mg g?1 CPAM with 5 million MW and 40% CD, 6 mg g?1 CPAM with 3 million MW and 40% CD, and 10 mg g?1 CPAM with 5 million MW and 20% CD, respectively. Hence, the CPAM with 5 million MW and 60% CD was ideal for sludge dewatering.

Pan, Chengyi

2014-01-01

300

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

PubMed

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

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

2011-04-01

301

Bioelectrochemical desalination and electricity generation in microbial desalination cell with dewatered sludge as fuel.  

PubMed

Microbial desalination cells (MDCs) with common liquid anodic substrate exhibit a slow startup and destructive pH drop, and abiotic cathodes have high cost and low sustainability. A biocathode MDC with dewatered sludge as fuel was developed for synergistic desalination, electricity generation and sludge stabilization. Experimental results indicated that the startup period was reduced to 3d, anodic pH was maintained between 6.6 and 7.6, and high stability was shown under long-term operation (300d). When initial NaCl concentrations were 5 and 10g/L, the desalinization rates during stable operation were 46.37±1.14% and 40.74±0.89%, respectively. The maximum power output of 3.178W/m(3) with open circuit voltage (OCV) of 1.118V was produced on 130d. After 300d, 25.71±0.15% of organic matter was removed. These results demonstrated that dewatered sludge was an appropriate anodic substrate to enhance MDC stability for desalination and electricity generation. PMID:24534793

Meng, Fanyu; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Guodong; Fan, Qingxin; Wei, Liangliang; Ding, Jing; Zheng, Zhen

2014-04-01

302

Use of dewatered alum sludge as a substrate in reed bed treatment systems for wastewater treatment.  

PubMed

In this paper, two laboratory-scale simulated reed beds were investigated for the purpose of assessing the feasibility and effectiveness of using dewatered alum sludge as a possible substrate for wastewater treatment reed bed systems. One horizontal subsurface flow setup and one vertical flow setup were used. The horizontal flow system was planted with Phragmites australis while the vertical flow system was left unplanted. Thus, the latter was more akin to a sand filter system, but was examined with the potential use as a planted vertical reed bed system. The influent source used was farmyard wastewater. It is expected that the present study will provide the basis for long-term and large-scale trials in realizing the concept of integrating "waste" into treatment processes. Results obtained so far have shown that the dewatered alum sludge holds great promise as a low-cost resource media for use in reed bed treatment systems. Appreciable and stable performance was obtained during the continuous operation at high hydraulic, organic and phosphorus loadings. In particular, both wetlands achieved over 90% phosphorus removal, reflecting the significant advantage of this novel approach over conventional reed bed treatment systems. However, extensive research into possible surface clogging and possible release of some substances from the sludge to the treated effluent is necessary to ensure reliability of the system. This will help to make the alum sludge-based reed bed environmentally and economically justifiable. PMID:18161564

Zhao, Y Q; Babatunde, A O; Razali, M; Harty, F

2008-01-01

303

Process for utilizing a pumpable fuel from highly dewatered sewage sludge  

SciTech Connect

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

Khan, M.R.

1993-08-10

304

Comparison of two dynamic measurement methods of odor and odorant emission rates from freshly dewatered biosolids.  

PubMed

Odor and odorant emission rates from freshly dewatered biosolids in a dewatering building of a Water Reclamation Plant (WRP) are measured using the EPA flux chamber and wind tunnel methods. Experimental results are compared statistically to test whether the two methods result in similar emission rates when experiments are performed under field conditions. To the best of our knowledge the literature is void of studies comparing the two methods indoors. In this paper the two methods are compared indoors where the wind velocity and air exchange rate are pertinent field conditions and can be measured. The difference between emission rates of odor and hydrogen sulfide measured with the two methods is not statistically significant (P values: 0.505 for odor, 0.130 for H(2)S). It is concluded that both methods can be used to estimate source emissions but selection of the most effective or efficient method depends on prevailing environmental conditions. The wind tunnel is appropriate for outdoor environments where wind effects on source emissions are more pronounced than indoors. The EPA flux chamber depends on the air exchange rate of the chamber, which simulates corresponding conditions of the indoor environment under investigation and is recommended for estimation of indoor pollution sources. PMID:21552636

Wang, Tingting; Sattayatewa, Chakkrid; Venkatesan, Dhesikan; Noll, Kenneth E; Pagilla, Krishna R; Moschandreas, Demetrios J

2011-06-01

305

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

306

The role of temperature and CaCl2 in activated sludge dewatering under hydrothermal treatment.  

PubMed

Dewatering is important for activated sludge disposal. The dewaterability of activated sludge was first deteriorated and then ameliorated when the temperature was raised from 100 to 200 °C with a threshold temperature of 130 °C under hydrothermal treatment. Calcium chloride assisted hydrothermal treatment to improve the dewaterability of activated sludge, and eliminated the threshold temperature at as less as 20 mg/g dry solid (DS). An increase in temperature and dosage of CaCl2 till 60 mg/g DS allowed a continuous improvement of dewaterability. It is found that the charge neutralization resulted from biopolymers solubilization dominated the dewaterability evolution below 160 °C, while the decomposition of water-binding components played a more important role at higher temperatures. The variation of molecular weight of soluble protein and polysaccharides implies that CaCl2 interacted with the component of sludge and altered the constituent during the hydrothermal treatment. The integration of soluble biopolymers into the floc matrix by CaCl2 contributed to the compacted floc structure and thus improved the dewaterability. This work presents an insight into the floc variation in both the composition and structure associated with the dewaterability and offers a new understanding to the role of temperature and CaCl2 in hydrothermal treatment on activated sludge dewatering. PMID:24355330

Yu, Jie; Guo, Minhui; Xu, Xinhua; Guan, Baohong

2014-03-01

307

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

308

A novel acrylamide-free flocculant and its application for sludge dewatering.  

PubMed

In the present research, copolymers of methyl acrylate (MA) with anionic or cationic monomers were synthesized via emulsion polymerization, and used as sludge dewatering aids in wastewater treatment. The copolymerization of different stoichiometry of two monomers afforded a variety of water soluble copolymers with charge densities ranging from 40% to 80%, which align with the charge density of current flocculant products. These copolymers resemble current commercial products, but provide a greener solution by eliminating acrylamide monomer, which is a suspected carcinogen. High molecular weight copolymers were achieved by applying powder-like synthesis process with intrinsic viscosity of final products as high as 12.98 dl/g for anionic flocculant and 10.74 dl/g for cationic flocculant. The copolymers of methyl acrylate and [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AETAC) with 55% charge density exhibited comparable performance in clay settling test, real water jar test, and sludge dewatering, when compared to AM-based commercial product in the real wastewater treatment application. PMID:24731856

Lu, Lianghua; Pan, Zhida; Hao, Nan; Peng, Wenqing

2014-06-15

309

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

National Technical Information Service (NTIS)

This report outlines the performance of a Geotube dewatering system which was introduced for evaluation by the Miratech Division of Ten Cate Nicolon and General Chemical Corporation. This system uses a chemical pre-treatment to coagulate the solids from t...

2006-01-01

310

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

Microsoft Academic Search

The primary goal of the current coal preparation research is to reduce the ash and sulfur content from coal, using fine grinding and various coal cleaning processes to separate finely disseminated mineral matter and pyrite from coal. Small coal particles are produced by the grinding operation, thus the ultrafine coal becomes very difficult to dewater. In addition, the ultrafine coal

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

1995-01-01

311

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

Microsoft Academic Search

The primary goal of the ongoing ICCI coal preparation research project is to reduce ash and sulfur content in coal by using fine grinding and other coal cleaning processes. The ultrafine coal particles that result from the grinding and cleaning operations are difficult to dewater, and create problems in their storage, handling and transportation. The objective of this research is

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

1997-01-01

312

Pilot Scale Single Stage Fine Coal Dewatering and Briquetting Process. Technical report, March 1, 1996 - May 31, 1996  

Microsoft Academic Search

The primary goal for this ICCI coal research project is to effectively liberate coal from fnely disseminated minerals for Illinois Basin coal by using fine grinding and cleaning processes. However, because of the large surface area generated during the cleaning processes, it is difficult and uneconomic for conventional techniques to dewater the coal fines. In addition, these coal fine pose

J. W. Wilson; R. Q. Honaker; Y. Ding; K. Ho

1996-01-01

313

Fundamental Study for Improvement of Dewatering of Fine Coal/Refuse. Final Report, August 1981-December 1984.  

National Technical Information Service (NTIS)

Fine coal in slurry form must be dewatered to minimize handling and transportation problems and be reduced to a desirable level for subsequent preparation of coal/water mixtures as a substitute utility fuel. The current practice is inadequate for the dewa...

S. H. Chiang G. E. Klinzing B. I. Morsi J. W. Tierney T. Binkley

1984-01-01

314

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

PubMed

Dewatered sewage sludge (approximately 80% water, but with low fluidity) was liquidized by hydrothermal treatment in order to make coal-water paste (CWP) for use in a pressurized-fluidized-bed-combustion (PFBC) power plant. Prediction of the viscosity of the dewatered sewage sludge during batch reactor hydrothermal liquefaction is important in order to avoid inputting excess energy. A single parameter, the severity parameter, has been used to predict viscosity during the hydrothermal process. The relationship between the viscosity of the slurry made from dewatered sewage sludge and the severity value was investigated. Viscosity reduction was associated with an increase in the severity value and was dependent on reaction temperature and time. It was concluded that predicting the viscosity of dewatered sewage sludge during the hydrothermal process by means of the severity parameter is possible. This method is expected to provide a useful guideline for choosing reaction conditions based on prediction of the viscosity of the sludge slurry during the hydrothermal process. PMID:19850471

Yanagida, Takashi; Fujimoto, Shinji; Minowa, Tomoaki

2010-03-01

315

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

316

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

317

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

318

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

319

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

320

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

321

UV-Initiated Polymerization of Cationic Polyacrylamide: Synthesis, Characterization, and Sludge Dewatering Performance  

PubMed Central

P(AM-DAC-BA) was synthesized through copolymerization of acrylamide (AM), acryloyloxyethyl trimethyl ammonium chloride (DAC), and butylacrylate (BA) under ultraviolet (UV) initiation using response surface methodology (RSM). The influences of light intensity, illumination time, and photoinitiator concentration on the intrinsic viscosity [?] of P(AM-DAC-BA) were investigated. RSM model based on the influencing data was established for optimizing synthetic conditions. It was found that, at light intensity 1491.67??w·cm?2, illumination time 117.89?min, and photoinitiator concentration 0.60‰, there was a better material performance achieved. Thus P(AM-DAC-BA) prepared under the above conditions showed excellent dewatering performance that, with 40?mg·L?1 P(AM-DAC-BA) at pH 7, the residual turbidity of supernatant and the dry solid content were up to 38 NTU, 28.5%, respectively.

Zheng, Huaili; Sun, Yongjun; Tan, Mingzhuo; Chen, Wei; Liao, Yong

2013-01-01

322

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

323

Parallel studies on dewatering and conditioning of an alum sludge and an aluminium hydroxide suspension.  

PubMed

The paper shows a comparison between properties of an alum sludge gained from the coagulation of a coloured water with those of a suspension of aluminium hydroxide at a concentration equivalent to the coagulant fraction within the sludge. Background information is provided on composition and aspects of the source floc. The comparisons embraced floc size, polymer adsorption, and dewatering parameters including specific resistance to filtration, capillary suction time and the equilibrium moisture content under pressure. In all cases, there were strong similarities in the behaviour of the two suspensions. It is suggested that such features emanate from a common fractal structure within the source floc, whose fractal index (approximately/= 1) has been found to be insensitive to the composition of the floc. PMID:11794669

Papavasilopoulos, E N; Bache, D H

2001-01-01

324

Do alternate bacterial indicators and pathogens increase after centrifuge dewatering of anaerobically digested biosolids?  

PubMed

The objectives of this research were to evaluate the potential for sudden increase and/or regrowth of alternative bacteria as either indicators or pathogens after dewatering of thermophilic and mesophilically digested biosolids. The results showed that, in general, for thermophilic processes, even when a statistically significant (p < 0.05) sudden increase and regrowth occurred for fecal coliforms, Escherichia coli, and Enterococci, it did not occur for Salmonella or Aeromonas. For the mesophilic process evaluated, sudden increase did not occur, but regrowth occurred for fecal coliforms, E. coli, Enterococci, and Salmonella. The results have implications for Class A and B biosolids regulations, as both fecal coliform and Salmonella are part of the regulatory limits. The results also suggest that the public health risks are minimal, as a result of the potential sudden increase and regrowth that may occur. PMID:22195428

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

2011-11-01

325

UV-Initiated polymerization of cationic polyacrylamide: synthesis, characterization, and sludge dewatering performance.  

PubMed

P(AM-DAC-BA) was synthesized through copolymerization of acrylamide (AM), acryloyloxyethyl trimethyl ammonium chloride (DAC), and butylacrylate (BA) under ultraviolet (UV) initiation using response surface methodology (RSM). The influences of light intensity, illumination time, and photoinitiator concentration on the intrinsic viscosity [?] of P(AM-DAC-BA) were investigated. RSM model based on the influencing data was established for optimizing synthetic conditions. It was found that, at light intensity 1491.67? ? w·cm(-2), illumination time 117.89?min, and photoinitiator concentration 0.60‰, there was a better material performance achieved. Thus P(AM-DAC-BA) prepared under the above conditions showed excellent dewatering performance that, with 40?mg·L(-1) P(AM-DAC-BA) at pH 7, the residual turbidity of supernatant and the dry solid content were up to 38 NTU, 28.5%, respectively. PMID:24459451

Zheng, Huaili; Sun, Yongjun; Tang, Xiaomin; Tan, Mingzhuo; Ma, Jiangya; Chen, Wei; Liao, Yong

2013-12-24

326

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

PubMed

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

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

2011-01-01

327

Development of the Electroacoustic Dewatering (EAD) process for fine/ultrafine coal. Fifth quarterly progress report, period ending December 31, 1989.  

National Technical Information Service (NTIS)

Battelle, in cooperation with the Electric Power Research Institute (EPRI), CQ, Inc., Ashbrook-Simon-Hartley (ASH), Lewis Corporation, and Professor S. H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine...

B. F. Jirjis N. Senapati R. Menton P. Hsieh S. P. Chauhan

1990-01-01

328

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal. Seventh quarterly progress report period ending June 30, 1990.  

National Technical Information Service (NTIS)

Battelle, in cooperation with the Electric Power Research Institute (EPRI) CQ, Inc., Ashbrook-Simon-Hartley (ASH), and Professor S. H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine and ultrafine coals...

B. C. Kim C. L. Criner H. Wu N. Senapati S. P. Chauhan

1990-01-01

329

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

330

Feasibility of applying forward osmosis to the simultaneous thickening, digestion, and direct dewatering of waste activated sludge.  

PubMed

The feasibility of applying forward osmosis (FO) to the simultaneous thickening, digestion, and dewatering of waste activated sludge was investigated. After 19 days of operation, the total reduction efficiencies of the simultaneous sludge thickening and digestion system in terms of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) were approximately 63.7% and 80%, respectively, and the MLVSS/MLSS ratio continuously decreased from 80.8% to 67.2%. The MLSS concentration reached 39 g/L from an initial amount of 7 g/L, indicating a good thickening efficiency. In using FO for sludge dewatering, two major factors were verified, namely, initial sludge depth and draw solution (DS) concentration. A sludge depth of 3mm, where a dry sludge content of approximately 35% can be achieved in approximately 60 min, is recommended for future applications. In addition, the present study proved the feasibility of using seawater reverse osmosis concentrate as the DS. PMID:22209406

Zhu, Hongtao; Zhang, Liqiu; Wen, Xianghua; Huang, Xia

2012-06-01

331

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

332

Biodegradation of polyacrylamide by anaerobic digestion under mesophilic condition and its performance in actual dewatered sludge system.  

PubMed

Polyacrylamide (PAM) used in sludge dewatering widely exists in high-solid anaerobic digestion. Degradation of polyacrylamide accompanied with accumulation of its toxic monomer is important to disposition of biogas residues. The potential of anaerobic digestion activity in microbial utilization of PAM was investigated in this study. The results indicated that the utilization rate of PAM (as nitrogen source) was influenced by accumulation of ammonia, while cumulative removal of amide group was accorded with zeroth order reaction in actual dewatered system. The adjoining amide group can combined into ether group after biodegradation. PAM can be broken down in different position of its carbon chain backbone. In actual sludge system, the hydrolytic PAM was liable to combined tyrosine-rich protein to form colloid complex, and then consumed as carbon source to form monomer when easily degradable organics were exhausted. The accumulation of acrylamide was leveled off ultimately, accompanied with the yield of methane. PMID:24345566

Dai, Xiaohu; Luo, Fan; Yi, Jing; He, Qunbiao; Dong, Bin

2014-02-01

333

Coal-water interactions and preparation of dewatered ultra-fine clean coal: Final reoprt, January 1December 31, 1988  

Microsoft Academic Search

The mandate of this two-year project is to understand the mechanism responsible for coal-water interactions and the ways water is held by ultrafine coal. In addition, we are able to develop a bench-scale dewatering technique, based on heavy (<15\\/degree\\/ API), crude oil derived fractions treatment. In this first year, the work was largely focused on understanding coal-water interactions and on

V. M. Malhotra; R. N. Zitter

1989-01-01

334

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

Microsoft Academic Search

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

M. Citeau; O. Larue; E. Vorobiev

2012-01-01

335

Impact of sewage sludge conditioning and dewatering on the fate of nonylphenol in sludge-amended soils  

Microsoft Academic Search

The fate of 14C-labelled p353-nonylphenol (NP) in soils amended with differently treated sludges originating from the same precursor sludge was assessed. The effects of commonly applied conditioning and dewatering techniques were investigated. Nonylphenol was degraded considerably faster in soils amended with liquid sludge, while a significant portion of it remained intact and extractable by organic solvents when sludge had been

V. N. Kouloumbos; A. Schäffer; P. F.-X. Corvini

2008-01-01

336

Influence of surfactants on flocculation and dewatering of kaolin suspensions by cationic polyacrylamide (PAM-C) flocculant  

Microsoft Academic Search

This paper reports the result of studies on flocculation and dewatering of kaolin suspensions by cationic polyacrylamide (PAM-C) flocculants in presence of surfactants. The surfactants used were namely anionic sodium dodecyl sulphate (SDS), cationic cetyl trimethyl ammonium bromide (CTAB) and non-ionic TritonX 100, which is a polyoxyethylenic ether compound. The unflocculated kaolin has a very slow settling rate of about

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

2003-01-01

337

Influence of hydrolyzable metal ions on the interfacial chemistry, particle interactions, and dewatering behavior of kaolinite dispersions  

Microsoft Academic Search

The influence of hydrolyzable metal ions (Mn(II) and Ca(II)) adsorption on the surface chemistry, particle interactions, flocculation, and dewatering behavior of kaolinite dispersions has been investigated at pH 7.5 and 10.5. Metal ion adsorption was strongly cation type- and pH-dependent and significantly influenced the zeta potential, anionic polyacrylamide–acrylate flocculant (PAM) adsorption, shear yield stress, settling rate, and consolidation of kaolinite

Patience Mpofu; Jonas Addai-Mensah; John Ralston

2003-01-01

338

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

339

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

340

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

341

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

SciTech Connect

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

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

1992-12-31

342

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

343

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

344

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

345

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

346

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

347

A comprehensive insight into the combined effects of Fenton's reagent and skeleton builders on sludge deep dewatering performance.  

PubMed

Conditioning sewage sludge with Fenton's reagent and skeleton builders has been proved to be an effective mean to achieve deep dewatering. This work aimed to give a comprehensive insight into the mechanism involved. The results show that significant synergistic effect existed between Fenton's reagent and skeleton builders. With the optimum dosage, water content of dewatered sludge cake could be reduced to 49.5±0.5%. Furthermore, raw sludge existed in the form of zoogloea and its flocs surface was plate-like. After Fenton oxidation, partial of extracellular polymeric substances (EPS) was destroyed and the amounts of protein and polysaccharide dissolved in filtrate increased. Meanwhile, sludge flocs turned into smaller ones. After adding skeleton builders, constantly-changing environment promoted senescence and death of microorganism. A large area of plate-like structure disappeared, instead of which were holes. Irregular non-living things inlayed or pierced microbial cells, promoting the conversion from bound water to free water as well as further reduction of the sludge particle size. Additionally, these irregular substances could form a rigid porous structure under high pressure, which could transmit the stresses to the sludge internal parts and provide outflow channels for free water. Consequently, conditioned sludge was suitable for high pressure deep dewatering. PMID:23721731

Liu, Huan; Yang, Jiakuan; Zhu, Nairuo; Zhang, Hao; Li, Ye; He, Shu; Yang, Changzhu; Yao, Hong

2013-08-15

348

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

349

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

PubMed

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

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

2013-05-15

350

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

351

Improved dewatering behavior of clay minerals dispersions via interfacial chemistry and particle interactions optimization.  

PubMed

Orthokinetic flocculation of clay dispersions at pH 7.5 and 22 degrees C has been investigated to determine the influence of interfacial chemistry and shear on dewatering and particle interactions behavior. Modification of pulp chemistry and behavior was achieved by using kaolinite and Na-exchanged (swelling) smectite clay minerals, divalent metal ions (Ca(II), Mn(II)) as coagulants and anionic polyacrylamide copolymer (PAM A) and non-ionic polyacrylamide homopolymer (PAM N) as flocculants. The pivotal role of shear, provided by a two-blade paddle impeller, was probed as a function of agitation rate (100-500 rpm) and time (15/60 s). Particle zeta potential and adsorption isotherms were measured to quantify the interfacial chemistry, whilst rheology and cryogenic SEM were used to investigate particle interactions and floc structure and aggregate network, respectively. Osmotic swelling, accompanied by the formation of "honeycomb" particle network structure and high yield stress, was produced by the Na-exchanged smectite, but not kaolinite, dispersions. Dispersion of the clay particles in 0.05 M Ca(II) or Mn(II) solution led to a marked reduction in particle zeta potential, complete suppression of swelling, honeycomb network structure collapse and a concomitant reduction in shear yield stress of smectite pulps. Optimum conditions for improved, orthokinetic flocculation performance of negatively charged clay particles, reflecting faster settling flocs comprised (i) coagulation, (ii) moderate agitation rate, (iii) shorter agitation time, and (iv) anionic rather than non-ionic PAM. The optimum dewatering rates were significantly higher than those produced by standard, manual-mixing flocculation techniques (plunging and cylinder inversion) commonly used in industry for flocculant trials. The optimum flocculation conditions did not, however, have a significant impact on the final sediment solid content of 20-22 wt%. Further application of shear to pre-sedimented pulps improved consolidation by 5-7 wt% solid. Higher shear yield stresses and greater settling rates were displayed by PAM A based than PAM N based pulps and this is attributed to the former's more expanded interfacial conformation and greater clay particles bridging ability. It appears that the intrinsic clay particles' physico-chemical properties and interactions limit compact pulp consolidation. PMID:16038921

McFarlane, Angus; Bremmell, Kristen; Addai-Mensah, Jonas

2006-01-01

352

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

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

353

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

354

Effect of charge neutralization on the dewatering performance of alum sludge by polymer conditioning.  

PubMed

Cationic and anionic polymers with the same molecular weight were used as sludge conditioning reagent to study the polymer charge effect on alum sludge dewatering characteristics. On the basis of capillary suction time, bound water content, and zeta-potential measurement in this study, the function of charge neutralization appears to be an important consideration in the sludge dewaterability and moisture content. Using the dilatometric technique to measure the bound water content, we found that alum sludge conditioned by cationic polymer presented more significant variation in the bound water content than sludge subject to anionic conditioning. We hypothesise that the mechanism of charge neutralization caused much water depletion by replacement and exclusion in sludge and results in the decrease of bound water within the cationic polymer conditioning. An insignificant bound water variation found during the anionic conditioning resulted from the lack of charge neutralization. A lighter and looser floc structure is also be found in the anionic conditioned sludge after the analysis of wet floc density and fractal dimension. Such open floc structure can be attributed to the lack of charge neutralization as the flocs aggregate with anionic polymer. PMID:11794672

Wu, C C; Wu, J J

2001-01-01

355

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 9g/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

356

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

PubMed

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

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

2012-03-01

357

Mining nutrients (N, K, P) from urban source-separated urine by forward osmosis dewatering.  

PubMed

Separating urine from domestic wastewater promotes a more sustainable municipal wastewater treatment system. This study investigated the feasibility of applying a forward osmosis (FO) dewatering process for nutrient recovery from source-separated urine under different conditions, using seawater or desalination brine as a low-cost draw solution. The filtration process with the active layer facing feed solution exhibited relatively high water fluxes up to 20 L/m(2)-h. The process also revealed relatively low rejection to neutral organic nitrogen (urea-N) in fresh urine but improved rejection of ammonium (50-80%) in hydrolyzed urine and high rejection (>90%) of phosphate, potassium in most cases. Compared to simulation based on the solution-diffusion mechanism, higher water flux and solute flux were obtained using fresh or hydrolyzed urine as the feed, which was attributed to the intensive forward nutrient permeation (i.e., of urea, ammonium, and potassium). Membrane fouling could be avoided by prior removal of the spontaneously precipitated crystals in urine. Compared to other urine treatment options, the current process was cost-effective and environmentally friendly for nutrient recovery from urban wastewater at source, yet a comprehensive life-cycle impact assessment might be needed to evaluate and optimize the overall system performance at pilot and full scale operation. PMID:24564179

Zhang, Jiefeng; She, Qianhong; Chang, Victor W C; Tang, Chuyang Y; Webster, Richard D

2014-03-18

358

Environmental assessment of different dewatering and drying methods on the basis of life cycle assessment.  

PubMed

Sewage sludge is an inevitable product of wastewater treatment in municipal wastewater plants and its amount has increased dramatically due to the growing number of sewage systems users. This sludge needs to be adequately treated in order to decrease its hazardous properties and any negative influence on the environment. In this paper, gate to gate analysis, on the basis of life cycle assessment (LCA), was carried out in order to compare the environmental impact of alternative ways of sludge processing employing a dewatering press and three different kinds of dryers - belt dryer, container dryer and batch dryer. SimaPro 7.2 software and Ecoinvent 2.2 database were used to estimate the carbon footprint and energy balance of these processes. The main energy consumption in the scenarios analyzed is caused by the drying process. The solution based on application of the batch dryer allows a saving of 39.6% of energy compared with the most energy-consuming solution using a belt dryer. Sludge processing using belt and container dryers cause greater environmental burdens. PMID:24569277

Stefaniak, J; Zelazna, A; Paw?owski, A

2014-01-01

359

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

360

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

PubMed

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

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

2013-01-01

361

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

362

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

363

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

364

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

365

Actively dewatering fluid-rich zones along the Costa Rica plate boundary fault  

NASA Astrophysics Data System (ADS)

New 3D seismic reflection data reveal distinct evidence for active dewatering above a 12 km wide segment of the plate boundary fault within the Costa Rica subduction zone NW of the Osa Peninsula. In the spring of 2011 we acquired a 11 x 55 km 3D seismic reflection data set on the R/V Langseth using four 6,000 m streamers and two 3,300 in3 airgun arrays to examine the structure of the Costa Rica margin from the trench into the seismogenic zone. We can trace the plate-boundary interface from the trench across our entire survey to where the plate-boundary thrust lies > 10 km beneath the margin shelf. Approximately 20 km landward of the trench beneath the mid slope and at the updip edge of the seismogenic zone, a 12 km wide zone of the plate-boundary interface has a distinctly higher-amplitude seismic reflection than deeper or shallower segments of the fault. Directly above and potentially directly connected with this zone are high-amplitude, reversed-polarity fault-plane reflections that extend through the margin wedge and into overlying slope sediment cover. Within the slope cover, high-amplitude reversed-polarity reflections are common within the network of closely-spaced nearly vertical normal faults and several broadly spaced, more gently dipping thrust faults. These faults appear to be directing fluids vertically toward the seafloor, where numerous seafloor fluid flow indicators, such as pockmarks, mounds and ridges, and slope failure features, are distinct in multibeam and backscatter images. There are distinctly fewer seafloor and subsurface fluid flow indicators both updip and downdip of this zone. We believe these fluids come from a 12 km wide fluid-rich segment of the plate-boundary interface that is likely overpressured and has relatively low shear stress.

Bangs, N. L.; McIntosh, K. D.; Silver, E. A.; Kluesner, J. W.; Ranero, C. R.; von Huene, R.

2012-12-01

366

Biogeochemical pathways that influence de-watering and consolidation of fluid fine tailings  

NASA Astrophysics Data System (ADS)

Approximately 1 million m3 of fluid fine tailings are produced every day in northern Alberta, Canada from processing of surface-mined oil sands resources. The tailings, comprising an aqueous suspension of fines dominated by clay particles that remain dispersed for decades, are deposited into tailings ponds for containment, de-watering and consolidation. Slow consolidation of clays retained in tailings ponds hinders recovery and re-use of water, retards volume reduction and presents a technical challenge for effective tailings ponds management. Here, we reveal that microorganisms indigenous to oil sands tailings ponds change the surface chemistry of clay particles and accelerate tailings consolidation by two biogeochemical pathways: one pathway shows that microorganisms metabolize organic substrates and produce carbon dioxide (CO2) and methane (CH4) in oil sands tailings. Dissolution of biogenic CO2 increases bicarbonate (HCO3-) concentrations in the pore water and reduces pore water pH, which dissolves carbonate minerals and releases cations from tailings minerals. The higher ionic strength of the pore water resulting from increased concentrations of ions shrinks the double diffuse layers of clay particles and hence increases consolidation. In addition, biogenic CH4 ebullition creates transient physical channels for recovery of pore water. The second pathway exerts a more direct microbial effect on consolidation through transformation of iron (Fe) minerals in oil sands tailings. Microbial reduction and dissolution of FeIII minerals forms amorphous FeII minerals that entrap and mask electronegative clay surfaces. These biogeochemical processes provide essential information for construction of geotechnical models to predict settling of clay particles for effective reclamation and management of fluid fine tailings.

Siddique, T.; Foght, J.

2013-12-01

367

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

PubMed

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

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

2008-09-01

368

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

369

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

370

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

371

Pilot Scale Single Stage Fine Coal Dewatering and Briquetting Process. Technical report, March 1, 1996 - May 31, 1996  

SciTech Connect

The primary goal for this ICCI coal research project is to effectively liberate coal from fnely disseminated minerals for Illinois Basin coal by using fine grinding and cleaning processes. However, because of the large surface area generated during the cleaning processes, it is difficult and uneconomic for conventional techniques to dewater the coal fines. In addition, these coal fine pose transportation, storage and handling problems at cleaning and utility facilities. The objective of this research is to combine dewatering and briquetting processes into a single stage operation that will solve the problems mentioned above. To build on the promising results obtained from the previous studies, a pilot scale commercial briquetting machine was used to evaluate this technique. The primary objective of the research in this reporting period is to determine the effectiveness of a single stage dewatering and briquetting technique using a commercial briquetting device. Two types of samples were prepared and the results of the -28 x 100 mesh samples are presented in this report. Modifications were made to the machine in an attempt to solve the back drainage problem. A total of six experiments were conducted and the results indicate that water resistance of coal briquettes increased as curing time increased. However, due to a deficiency of fine particles to bridge the gaps between the coarse particles, the wear resistance of the products declined. Also, at high roll speeds and compaction pressures, the coal briquettes produced tended to have higher moisture content and lower strength. On the other hand, at high feed rates, because of the screw extrusion effect, coal briquettes were produced with lower moisture content and higher strengths.

Wilson, J.W. [Missouri Univ., Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q.; Ding, Y. [Southern Illinois Univ., Carbondale, IL (United States); Ho, K. [Illinois Clean Coal Inst., Carterville, IL (United States)

1996-12-31

372

[Optimized cultivation of a bioflocculant M-C11 produced by Klebsiella pneumoniae and its application in sludge dewatering].  

PubMed

A bioflocculant-producing Klebsiella pneumoniae strain C11 was screened out from activated sludge and the optimal medium conditions for the production of microbial flocculant M-C11 were determined. The bioflocculant was used in activated sludge dewatering and compared with conventional chemical conditioners. Effects of pH, CaCl2 dosages and M-C11 dosages on sludge dewaterability were investigated. The optimized conditions for M-C11 production indicated that the optimal medium carbon, nitrogen, metal ion were 30 g x L(-1) glucose, 2 g x L(-1) NaNO3 and 0.5 g x L(-1) MgSO4, respectively. The flocculating rate with kaolin suspension was as high as 91.70%, when incubated in a rotary shaker at 150 r x min(-1) and 37 degrees C for 48 h. The microbial focculant showed excellent pH and thermal stability over a pH range of 4-8 and a temperature range of 20-60 degrees C. Then the bioflocculant M-C11 produced by Klebsiella pneumoniae was employed to enhance the sludge dewaterability. The sludge resistance to filtration (SRF) and cake moisture decreased from 11.64 x 10(12) m x kg(-1) and 98.86% to 4.66 x 10(12) m x kg(-1) and 83.74%, respectively. Sludge dewatering performance was more significantly improved with the optimal conditioning dosages (pH = 6, 3 mL M-C11, 4 mL CaCl2), than inorganic flocculating reagents such as aluminum sulfate and polymeric aluminum chloride (PAC). The microbial flocculant has advantages over traditional sludge conditioners for its lower cost, benign biodegradability and ignorable secondary pollution. In addition, it was favorably adapted to the sludge pH and salinity. The novel bioflocculant could be used as a potential conditioner for sludge dewatering. PMID:24881415

Liu, Jie-Wei; Ma, Jun-Wei; Liu, Yan-Zhong; Yang, Ya; Yue, Dong-Bei; Wang, Hong-Tao

2014-03-01

373

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

374

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

375

Coal-water interactions and preparation of dewatered ultra-fine clean coal: Final reoprt, January 1--December 31, 1988  

SciTech Connect

The mandate of this two-year project is to understand the mechanism responsible for coal-water interactions and the ways water is held by ultrafine coal. In addition, we are able to develop a bench-scale dewatering technique, based on heavy (<15/degree/ API), crude oil derived fractions treatment. In this first year, the work was largely focused on understanding coal-water interactions and on determining which types of water were amenable to dewatering. To accomplish this, four types of measurements were made on Hagel lignite and oxidized Illinois bituminous coal: (1) desorption of water from pure KBr pellets, (2) desorption of water from coal-KBr pellets, (3) desorption of water thin films of coal deposited on AgBr and CaF/sub 2/ optical substrates and (4) the dynamics of water at 100K < T < 460K. The water's desorption kinetics data, as determined by FTIR technique from pure KBr pellets, can best be described by a three-dimensional diffusion desorption model with an activation carrier of 37 kJ mol/sup /minus/1/. 31 refs., 34 figs., 13 tabs.

Malhotra, V.M.; Zitter, R.N.

1989-03-01

376

The assessment of human exposure to radionuclides from a uranium mill tailings release and mine dewatering effluent.  

PubMed

This study provides an assessment of human exposure to radiation from a river system contaminated by radionuclides of the 238U decay series released through a dam break at a uranium mill tailings pond and by the continuous discharge of dewatering effluent from 2 uranium mines. The in vivo analyses of radionuclides in 6 Navajo Indians who lived near the river indicate no detectable elevations above background concentrations. Dose estimates for inhalation of suspended river sediment indicate a maximum annual 50-yr dose commitment of 204 mrem to the endosteum. Estimates of doses (50-yr dose commitments) from the ingestion of livestock range between 1 mrem (to liver) and 79 mrem (to bone) suggest that the major contribution to human exposure is from mine dewatering effluent that has been continuously released into the river system for many years. Although the estimated exposures do not exceed existing state or federal regulations, their magnitude justifies further measurement of radionuclides in animals and in the natural environment and the consideration of strategies to reduce radiation exposure to humans and animals. PMID:6469647

Ruttenber, A J; Kreiss, K; Douglas, R L; Buhl, T E; Millard, J

1984-07-01

377

Low frequency ultrasound-assisted leaching of sewage sludge for toxic metal removal, dewatering and fertilizing properties preservation.  

PubMed

The aim of this research was to evaluate the efficiency of an ultrasonication process in combination with METIX-AC technology, a chemical process, for metal removal and dewatering ability, with preservation of fertilizing properties of sewage sludge. Waste activated sludge samples having a total solids concentration of 4 and 20 g L(-1), were enriched with Cu and Zn in order to exceed the limiting values recommended by Québec regulation for sludge valorization. Ultrasonication was applied at low frequency (22 kHz) at specific energies ranging from 180 to 66,000 kJ kg(-1) of dry sludge. Ultrasound-assisted leaching rates and yields were similar to chemical leaching alone for Zn, whereas solubilisation was reduced for Cu, regardless the specific energy. Fertilizing properties preservation and dewatering ability were similar in ultrasound-assisted leaching, compared to chemical leaching alone. These trends were mainly attributed to the changes of metal speciation, particle size and morphology during ultrasonication, in addition to untreated sludge properties. PMID:22947498

de La Rochebrochard, Samuel; Naffrechoux, Emmanuel; Drogui, Patrick; Mercier, Guy; Blais, Jean-François

2013-01-01

378

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

379

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

380

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

National Technical Information Service (NTIS)

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 nov...

J. G. Groppo B. K. Parekh

1995-01-01

381

Floc destruction and its impact on dewatering properties in the process of using flat-sheet membrane for simultaneous thickening and digestion of waste activated sludge.  

PubMed

Floc destruction and its impacts on the dewatering properties in terms of capillary suction time (CST) in the process of using flat-sheet membrane for simultaneous thickening and digestion (MSTD) of waste activated sludge were investigated. A pilot-scale MSTD reactor was used to treat waste activated sludge, and extracellular polymeric substances (EPS), soluble biopolymers, dissolved cations and the dewatering properties were measured. The results indicated that the destruction mechanisms of the MSTD process could be divided into two phases due to the variation of dissolved oxygen (DO). Polysaccharides and proteins were released in both phases, but the release patterns were different. The concentration of polysaccharides was much greater than that of proteins in Phase 1, while the ratio of proteins to polysaccharides ranged from 1.5 to 1.7. The divalent cations in supernatant significantly increased in Phase 1, while the monovalent cations in supernatant rose in Phase 2. The dewatering properties in terms of CST significantly increased in the MSTD process, and the mixed liquor suspended solids (MLSS), particle size, and biopolymers in supernatant had significant effects on the dewatering properties. PMID:19038542

Wang, Xinhua; Wu, Zhichao; Wang, Zhiwei; Yin, Xing; Du, Xingzhi

2009-03-01

382

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

383

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

PubMed

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

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

2012-07-01

384

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

385

Impact of sewage sludge conditioning and dewatering on the fate of nonylphenol in sludge-amended soils.  

PubMed

The fate of (14)C-labelled p353-nonylphenol (NP) in soils amended with differently treated sludges originating from the same precursor sludge was assessed. The effects of commonly applied conditioning and dewatering techniques were investigated. Nonylphenol was degraded considerably faster in soils amended with liquid sludge, while a significant portion of it remained intact and extractable by organic solvents when sludge had been centrifuged before soil amendment. Mineralization was reduced or even inhibited when freeze-thaw or lime conditioning was applied, respectively. Flocculation by an acrylamide-based cationic polymer led to the formation of a nitro-addition product of nonylphenol in soil, as well to decreased mineralization rates after prolonged incubation times. Possible mechanisms underlying the observations are suggested and discussed. PMID:18694585

Kouloumbos, V N; Schäffer, A; Corvini, P F-X

2008-08-01

386

The prediction of filter belt press dewatering efficiency for activated sludge by experimentation on filtration compression cells.  

PubMed

The filter belt press is commonly used to dewater activated sludge. However, little research has been done on this process and the prediction of its efficiency. Experimentation has been carried out in a filtration compression cell (FCC) and in a pilot scale filter belt press. It offers a way of determining filter belt press efficiency thanks to simple laboratory research. The pressure distribution around the pressing roller was measured inside the pilot scale filter belt press. It showed progressive increase (up to a certain maximum value: plateau), which was followed by a rapid decrease. The impact of the progressive increase of applied pressure onto the dry solid sludge content was observed in FCC. Similar dry solid contents were obtained from both the above laboratory devices when the application of the pressure is comparable (in time and increasing rate). PMID:15691203

Olivier, J; Vaxelaire, J

2004-12-01

387

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

SciTech Connect

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

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

1997-05-01

388

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

389

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

USGS Publications Warehouse

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

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

2011-01-01

390

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

Microsoft Academic Search

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74μm) 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

J. G. Groppo; B. K. Parekh

1996-01-01

391

Evaluation of a Pilot-Scale, Plate-and-Frame Filter Press for Dewatering Thickener Underflow Slurries from Bituminous Coal-Cleaning Plants  

Microsoft Academic Search

Laboratory testing was conducted to evaluate the performance of a pilot-scale, plate-and-frame filter press for dewatering bituminous coal slurries. The fully automated filter press is manufactured by T.H. Minerals and is equipped with a hydraulic system, which operates the plate and diaphragm feed pumps. The filter press is capable of achieving an operating pressure of up to 1035 kPa. The unit

Shubham Verma; Mark S. Klima

2010-01-01

392

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

Microsoft Academic Search

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

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

1997-01-01

393

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

394

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

395

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

396

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

397

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

PubMed

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

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

2012-11-20

398

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

PubMed

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

Liu, Xiaoguang; Dong, Bin; Dai, Xiaohu

2013-11-01

399

Desaguamento de polpa kraft branqueada de fibra curta refinada: por gravidade, vacuo e centrifugacao com aplicacao de pressao Parte 2. Efeitos dos aditivos da parte umloa I Dewatering ofrefined, bleached hardwood kraft pulp by gravity, vacuum, and centrifugation with applied pressure  

Microsoft Academic Search

Several wet-end chemical additives significantly affected dewatering rates according to gravity drain­ age tests (freeness), the application ofvacuum, and a modified water retention value (MWR V) test. Relatively large increases in dewatering rates, including reductions in MWR V, were obtained hy addition ofhigh-charge synthetic cationic polymers to the pulp suspensions. Results were consistent with charge neutralization and polyelectrolyte complexation within

Mark Panczyk

400

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

401

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

PubMed

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 10 Mg DM ha(-1)yr(-1). Biosolids gave crop yields similar to the highest mineral fertiliser dressing. However, with the higher rate of liquid and dewatered sludge, excessive N supply was harmful, leading to wheat lodging and poor quality of sugar beet and wheat crops. From this standpoint compost use was safer. Biosolids increased organic matter (OM), total N, and available P in the soil and reduced soil alkalinity, with more evident effects at the highest rate. Compost caused the most pronounced OM top soil accumulation. Significant accumulations of total Zn and Cu were detected in amended top soil, but no other heavy metals (Cd, Cr, Ni, Pb), whose total concentration remained well below the hazard limits. Biosolid applications significantly increased the content of N, P, Zn, and Cu in wheat grain, N and Cu in sugar beet roots, and only Cu in maize grain. The application of biosolids brought about notable benefits to soil fertility but it was associated with possible negative effects on water quality due to increased P availability and on soil ecology due to Zn accumulation. PMID:15644237

Mantovi, Paolo; Baldoni, Guido; Toderi, Giovanni

2005-01-01

402

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

PubMed

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

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

2013-07-01

403

Metals removal from soil, fly ash and sewage sludge leachates by precipitation and dewatering properties of the generated sludge.  

PubMed

This study concerns the treatment by precipitation of three acidic and metal-rich leachates by using various reagents. Two treatment modes (simple and combined precipitation) have been performed to evaluate the metals removal efficiency and the dewatering ability of the generated sludge. It appears that for the three leachates used, the Ca(OH)(2) addition gave better metals removal at pH 10.0 than the use of NaOH at the same pH. Moreover, the combination of NaOH and Na(2)S allows better removal for Pb(2+), Zn(2+), Cu(2+) and Mn(2+) ions than with NaOH/Na(2)CO(3) or NaOH/Na(2)HPO(4). The dewaterability (vacuum filtration) of precipitates produced during the treatment of soil leachate was established as follows on the basis of the specific resistance to filtration (SRF) values: sulphides (4.3 x 10(12)mkg(-1))

Djedidi, Zied; Bouda, Médard; Souissi, Med Aly; Ben Cheikh, Ridha; Mercier, Guy; Tyagi, Rajeshwar Dayal; Blais, Jean-François

2009-12-30

404

Exploration of ground instability factor causing slumping and related dewatering in high methane-flux and gentle continental slope off Shimokita Peninsula, NE Japan  

NASA Astrophysics Data System (ADS)

A great number of slump (submarine landslide) units have been identified by reflection seismic surveys performed off Shimokita Peninsula, NE Japan (Morita, et al., 2011). A 3-D seismic data revealed typical deformations caused by slumping and related dewatering in the Pliocene and upper formations. The slumping was generated primarily by layer-parallel slip in a very gentle (<1 degree) and flat continental slope. The size of slump units extends over 30 km in both width and slip direction in maximum. The slump units often exhibit an imbrication structure formed by repeated thrusting in the bottom layers, being mostly composed of the thrust blocks and little matrix. The dewatering structure is observed as widespread parallel dikes of which distribution is strongly dependent on the imbrication of the slump units. Slip planes of the slumps are traceable in seismic data because of the layer-parallel slip. The layers which correspond to the slip planes proved to be generally characterized as low-amplitude layers having some thickness, and some of the slip planes exhibit flattened features under the slump units of the imbrication structure accompanied by parallel dikes. This implies that excess fluid in the slip plane caused the lubrication to enhance the slumping and was drained through the parallel dikes during slumping. Some typical structures related to natural gas, e.g. enhanced reflection, gas chimney, have been identified in the seismic data. The shakedown cruise of D/V Chikyu in 2006 reported a recovery of gas hydrate in nearby area (Higuchi et al., 2009). A shallow sulfate-methane interface (SMI) of 3.5-12 mbsf has been reported in the survey area (Kotani et al., 2007). These features indicate that a high methane flux in the area is likely an important ground instability factor to cause the slumping and the dewatering phenomena. We recognize that the set of the slump units in the survey area is one of the most suitable targets to approach mechanism of submarine landslides so that we started exploring the feasibility of a scientific drilling in this survey area.

Morita, S.; Nakajima, T.; Goto, S.; Yamada, Y.; Kawamura, K.

2012-12-01

405

Dewatering of Slimes.  

National Technical Information Service (NTIS)

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

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

1978-01-01

406

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

407

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

PubMed

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

Hong, Chen; Haiyun, Wu

2010-07-01

408

New insight into chemical changes of dissolved organic matter during anaerobic digestion of dewatered sewage sludge using EEM-PARAFAC and two-dimensional FTIR correlation spectroscopy.  

PubMed

Dissolved organic matter (DOM) is a key component in reaction network of anaerobic digestion. In this study, fluorescent excitation-emission matrix-parallel factor (EEM-PARAFAC) analysis and two-dimensional (2D) FTIR correlation spectroscopy were firstly used to explore chemical changes of soluble intermediates in high-solid biogas reactor. EEM-PARAFAC showed that fluorescent components (tyrosine-like, tryptophan-like and humic-like groups) in DOM over time increased gradually, implying that these groups were reluctant to biodegrade (acidogenesis). The resistance to biodegradation presented the following order: humic-like group>tyrosine-like group>tryptophan-like group. 2D FTIR correlation spectroscopy indicated that the DOM change sequence with time followed the order: protein-like groups>structural carbohydrates and carboxylic acids>polysaccharides-like groups. Fluorescence intensities from EEM-PARAFAC and main bands of FTIR spectra correlated significantly with other chemical parameters, e.g. biogas production and dissolved organic carbon content. These findings supply novel realization for degradation degree and order of individual DOMs during anaerobic digestion for dewatered sewage sludge. PMID:24681632

Li, Xiaowei; Dai, Xiaohu; Takahashi, Junichi; Li, Ning; Jin, Jingwei; Dai, Lingling; Dong, Bin

2014-05-01

409

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

410

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

PubMed

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

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

2010-04-01

411

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

412

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

413

A MECHANISM FOR ASH ASSISTED SLUDGE DEWATERING  

EPA Science Inventory

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

414

Thermally enhanced DAF sludge dewatering system  

SciTech Connect

Dissolved Air Flotation Sludge (DAF) produced by poultry processing plants has created problems due to its moisture content and rancidity. A thermal system under development could provide a cost effective solution to these problems.

Valentine, G.E.; Walsh, J.L.

1987-01-01

415

Tectonic controlled submarine slidings and dewatering structures  

Microsoft Academic Search

Geologic structures associated with mass movements processes such as slumping, sliding, and creeping can be the key to understanding the tectonic or geologic constraints in the time they were formed. Because they are sensitively reflected by the paleo-topography which must be associated with active tectonics. It must be very useful if the direction of paleo-slope instability is known easily in

Y. Yamamoto; T. Hirono; M. Takahashi

2003-01-01

416

Process Intensification for Drying and Dewatering  

Microsoft Academic Search

Background information on process intensification including the rationale, basic methods in process engineering, and interactions between material streams and processing methods is given. The general rules are then examined with respect to heat and mass transfer intensification, and pertinent to drying techniques and technologies (e.g., microwave drying, pulse combustion drying, intermittent drying, drying by alternation pressure, etc.) are highlighted. Milk

Marzouk Benali; Tadeusz Kudra

2010-01-01

417

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

418

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

419

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

420

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

421

High-G centrifuge test results: Fine coal dewatering  

Microsoft Academic Search

This paper presents the results of 18 high-G centrifuge tests performed at the Electric Power Research Institute's Coal Cleaning Test Facility in January 1985. These tests, using -28 mesh (0.6mm) froth flotation product, show that the high-G, solid-bowl centrifuge can produce clean-coal moistures of less than 12 percent at solids recovery rates exceeding 98 percent. The high-G centrifuge achieved these

C. D. Harrison; J. R. Cavalet

1985-01-01

422

Problem of dewatering clay slurries: factors controlling filtrability  

Microsoft Academic Search

The problem of removing water from suspensions of clays of the swelling class has not yet received a satisfactory solution. It presents serious difficulties in various mining operations, for example, in the treatment of aqueous effluent from the extraction of bitumen from Athabasca (Alberta) tar sands. The main difficulty lies not in clarification of the supernatant water, but in the

H. J. L. Wright; J. A. Kitchener

1976-01-01

423

Dewatering of contaminated sediments: Greenhouse and field studies  

Microsoft Academic Search

Water management of dredged sediments in Confined Disposal Facilities (CDFs) is an issue for the United States Army Corps of Engineers (USACE). Removing water from contaminated dredged sediments in CDFs is desirable because water removal can reduce the volume occupied by the sediments and can create the aerobic conditions needed for the microbial degradation of many contaminants found in the

K. E. Smith; M. K. Banks; A. P. Schwab

2009-01-01

424

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...

425

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...

426

Monitoring Earthquake Dewatering Processes Using MISR Satellite Data  

Microsoft Academic Search

The devastating Gujarat earthquake which hit the province of Gujarat in India on January 26, 2001, provoked an extensive liquefaction process. This presentation reports on the spatio-temporal distribution of this liquefaction-induced surface phenomenon by analyzing time seriesmeasurements collected by the MISR sensor on board the Terra platform.The analysis of MISR measurements in the near-infrared spectral domain reveals the spatial extent

B. Pinty; N. Gobron; M. M. Verstraete; F. Melin; J. Widlowski; Y. Govaerts; D. J. Diner; E. Fielding; D. L. Nelson; R. Madariaga; M. P. Tuttle

2004-01-01

427

Ultrafine coal single stage dewatering and briquetting process.  

National Technical Information Service (NTIS)

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

J. W. Wilson R. Q. Honaker

1995-01-01

428

Use of hydrocyclones for centrifugal dewatering of waste water sediments  

SciTech Connect

This article investigates the effectiveness of hydrocyclones in the separation of abrasive inclusions from the sediment of primary sedimentation tanks at the Orekhovo-Zuevo aeration station. The studies were performed in a pressure hydrocyclone which was fed with wet sediment from the primary sedimentation tanks with a water content of 93.8-95.5% and an ash content of 35.1-45.1%. The flow rate characteristics and the qualitative indices of the hydrocyclone operation, depending on its geometric parameters and inlet pressure, were determined. In the process of sediment separation in the hydrocyclones, the moisture content of the drained fluid rises above and that of the slime falls below the moisture content of the wet sediment. It is established that the pattern of change in the moisture content of the separation products, the content of the dry and mineral matters, and the efficiency of separation of the dry and mineral matters with the change in the pressure at the hydrocyclone inlet and its geometric parameters in the case of activated sludge treatment is similar to the pattern of change in the corresponding indices in the cases of hydrocyclone processing of the sediment from primary sedimentation tanks.

Lipmanovich, V.Y.

1984-07-01

429

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

430

COMPARISON OF GYPSUM DEWATERING TECHNOLOGIES AT FLUE GAS DESULFURIZATION PLANTS  

Microsoft Academic Search

Recovering gypsum from flue gas desulfurization (FGD) plants is becoming more important as the technical feasibility of substituting FGD gypsum for natural gypsum in traditional applications such as wall board, cement and soil conditioners has been demonstrated. It is estimated that there are over 200 new coal-fired plants and over 1000 upgrades of existing coal-fired plants in various stages around

Barry A. Perlmutter

431

Separation, Dewatering and Disposal of Sugar Beet Transport Water Solids.  

National Technical Information Service (NTIS)

The objectives of this study were to determine the settling characteristics of solids from sugar beet washing and fluming operations in a clarifier, the filtering characteristics of the underflow slurry from a clarifier and the disposal of the filter cake...

I. V. Fordyce A. M. Cooley

1974-01-01

432

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

433

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

434

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

435

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...

436

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

437

Surface Chemical Control of UltraFine Coal to Improve Dewatering  

Microsoft Academic Search

Lowering of filter cake moisture of ultra-fine (d50 = 25 µm) coal to a 20 percent level using the conventional vacuum filtration could be achieved using a combination of metal ions and surfactants. Pretreating coat slurry with about 0.2 Kg\\/ton of a surfactant and 50 ppm of copper or 10 ppm of aluminum ions provided filter cake containing 22.8 percent moisture. The lowering

J. G. GROPPO; B. K. PAREKH

1996-01-01

438

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

National Technical Information Service (NTIS)

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

J. W. Wilson

1996-01-01

439

Application of Ultra-Flocculation for Improving Fine Coal Concentrate Dewatering  

Microsoft Academic Search

The possibility of significant improvements in vacuum filtration of fine coal suspensions through the application of ultra-flocculation was studied. It was shown theoretically that even when present in quantities of a few percent, the ultrafine particles (<10 microns) highly contributed to the hydraulic resistance of the filter cake. The experiments showed that short-term hydrodynamic treatment of the coal suspension at

N. N. Rulyov; B. Y. Korolyov; N. M. Kovalchuk

2006-01-01

440

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

National Technical Information Service (NTIS)

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

J. W. Wilson R. Q. Honaker

1994-01-01

441

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. 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. 25 refs., 4 figs., 1 tab.

Suuberg, E.M.

1991-01-01

442

Use of surfactants to aid the dewatering of fine clean coal  

Microsoft Academic Search

Vacuum filtration of clean coal slurries and flocculated slurries with cationic, anionic and nonionic surfactants has been investigated. Significant reductions in filter cake moisture content were obtained for all types of surfactant. The most effective surfactant was CTAB. The final moisture content of filter cakes was reduced from 21 to 11.7 wt% by using a moderate dosage of flocculant followed

B. P. Singh; L. Besra; P. S. R. Reddy; D. K. Sengupta

1998-01-01

443

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

National Technical Information Service (NTIS)

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

H. L. Goodwin

2007-01-01

444

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

445

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

SciTech Connect

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

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

1990-07-24

446

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

447

Photoinitiated Polymerization of Cationic Acrylamide in Aqueous Solution: Synthesis, Characterization, and Sludge Dewatering Performance  

PubMed Central

A copolymer of acrylamide (AM) with acryloyloxyethyl trimethyl ammonium chloride (DAC) as the cationic monomer was synthesized under the irradiation of high-pressure mercury lamp with 2,2-azobis(2-amidinopropane) dihydrochloride (V-50) as the photoinitiator. The compositions of the photoinduced copolymer were characterized by Fourier transform infrared spectra (FTIR), ultraviolet spectra (UV), and scanning electron microscope (SEM). The effects of 6 important factors, that is, photo-initiators concentration, monomers concentration, CO(NH2)2 (urea) concentrations, pH value, mass ratio of AM to DAC, and irradiation time on the molecular weight and dissolving time, were investigated. The optimal reaction conditions were that the photo-initiators concentration was 0.3%, monomers concentration was 30?wt.%, irradiation time was 60 min, urea concentration was 0.4%, pH value was 5.0, and mass ratio of AM to DAC was 6?:?4. Its flocculation properties were evaluated with activated sludge using jar test. The zeta potential of supernatant at different cationic monomer contents was simultaneously measured. The results demonstrated the superiority of the copolymer over the commercial polyacrylamide as a flocculant.

Zheng, Huaili; Liao, Yi; Zheng, Meizhen; Zhu, Chuanjun; Ji, Fangying; Ma, Jiangya; Fan, Wei

2014-01-01

448

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

449

Shear sensitivity of digested sludge: Comparison of methods and application in conditioning and dewatering  

Microsoft Academic Search

Shear sensitivity of digested sludge was evaluated by two methods: a CST shear test and a strain sweep rheological method of measuring yield stress. Sludge pretreatment by an enzyme formulation was used to alter the sludge's response to shear and, potentially, to improve dewaterability. Also varied were the polymer conditioning dose and the amount of shear applied by mixing. A

Steven K. Dentel; Derya Dursun

2009-01-01

450

Improvement of the thickening and dewatering characteristics of activated sludge by electroflotation (EF).  

PubMed

The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30 minutes of EF operation, 57-84% of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. In addition, the EF thickened sludge showed much better dewaterability both in SRF and cake solid content. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed dewaterbility improvement. PMID:16459795

Choi, Y G; Kim, H S; Park, Y H; Jeong, S H; Son, D H; Oh, Y K; Yeom, I T

2005-01-01

451

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

PubMed

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

Zhang, Zhiqiang; Xia, Siqing; Zhang, Jiao

2010-05-01

452

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

453

Observing earthquake-related dewatering using MISR\\/Terra satellite data  

Microsoft Academic Search

On 26 January 2001, at 8:46 am, the Gujarat province of India (see Figure 1A) was hit by destructive earthquake.This earthquake, considered one of the two most damaging seismic events in Indian recorded history, caused the death of about 20,000 people and affected 16 million individuals. Both local residents and post-earthquake survey teams reported the fountaining of water and sediments

Bernard Pinty; Nadine Gobron; Michel M. Verstraete; Frédéric Mélin; Jean-Luc Widlowski; Yves Govaerts; David J. Diner; Eric Fielding; David L. Nelson; Raul Madariaga; Martitia P. Tuttle

2003-01-01

454

Modeling and Control of Algae Harvesting, Dewatering and Drying (HDD) Systems.  

National Technical Information Service (NTIS)

Alternative energy is a very important topic since there are some issues with the continued use of fossil fuel as a major source of energy. The alternative energy studied in this research is algae, which has received a lot of attention because it is easy ...

F. Li

2012-01-01

455

Use of Pulverized Coal to Enhance Sludge Dewatering and Incineration at Amherst Wastewater Treatment Facility.  

National Technical Information Service (NTIS)

The addition of pulverized coal to sewage sludge prior to incineration was investigated as a cost-saving measure for the 24 mgd two-stage complete-mix 'UNOX' activated sludge wastewater treatment plant with a physical-chemical tertiary treatment system in...

L. T. Thiem R. R. Roll

1983-01-01

456

Dewatering studies of fine clean coal. Technical report, September 1, 1990-November 30, 1990.  

National Technical Information Service (NTIS)

Physical cleaning of ultra-fine coal using advanced froth flotation technique provides a low ash product; however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicabil...

B. K. Parekh

1990-01-01

457

Amendment Free, Mechanically Enhanced Biodrying & Composting of Dewatered Undigested Sewage Sludge  

Microsoft Academic Search

Biodrying of manure is not an uncommon practice, but few active sewage sludge projects at full scale have been reported in the literature. During biodrying, heat from the composting microbiology is used to drive off moisture. Pathogen kill can also be accomplished provided the compost energetics support the required temperatures. In some facilities, the operator can choose between retaining the

Lewis Naylor; Richard Nicoletti; Matthew Calderiso

458

Rapid Dewatering Techniques for Dredged Lake Sediments. Literature Review and Summary Report.  

National Technical Information Service (NTIS)

Sediment removal from lakes and other water bodies has proven to be an effective method for removing contaminants and limiting the internal recycling of nutrients. There are many methods for dredging sediments, and in each case, the disposal of the dredge...

2007-01-01

459

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

460

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

461

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

Microsoft Academic Search

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

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

2002-01-01

462

Studies on the effect of flocculant adsorption on the dewatering of iron ore tailings  

Microsoft Academic Search

The adsorption characteristics of polyacrylamide polymer on iron ore tailings have been studied to understand the mechanism of adsorption. Adsorptions of both the anionic and non-ionic flocculants were analyzed using Langmuir isotherm and Freundlich isotherm. It was found that in comparison to the Langmuir model the Freundlich model was a better fit to the adsorption data according to the minimum

M. Dash; R. K. Dwari; S. K. Biswal; P. S. R. Reddy; P. Chattopadhyay; B. K. Mishra

2011-01-01

463

Shear-induced floc structure changes for enhanced dewatering of coal preparation plant tailings  

Microsoft Academic Search

The handling and disposal of industrial waste slurries containing colloidal particulate matter, with particular reference to coal and mineral processing plant tailings with a high proportion of clay materials present significant challenge. To develop effective disposal methods requires an improved understanding of floc structure that promote better water recovery and higher sediment density during settling and consolidation of flocculated tailings.

Philip Ofori; Anh V. Nguyen; Bruce Firth; Clint McNally; Orhan Ozdemir

2011-01-01

464

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

465

Digestion and dewatering characteristics of waste activated sludge treated by an anaerobic biofilm system.  

PubMed

Immobilization of microorganisms for sludge anaerobic digestion was investigated in this study. The effects of filler properties on anaerobic digestion and dewaterability of waste activated sludge were assessed at mesophilic temperature in batch mode. The results showed that the duration of the methanogenic stage of reactors without filler, with only filler, and with pre-incubated filler was 39days, 19days and 13days, respectively, during which time the protein was degraded by 45.0%, 29.4% and 30.0%, and the corresponding methane yield was 193.9, 107.2 and 108.2mL/g volatile suspended solids added, respectively. On day 39, the final protein degradation efficiency of the three reactors was 45.0%, 40.9% and 42.0%, respectively. The results of normalized capillary suction time and specific resistance to filtration suggested that the reactor incorporating pre-incubated filler could improve the dewaterability of digested sludge, while the effect of the reactor incorporating only filler on sludge dewaterability was uncertain. PMID:24355503

Wang, Tianfeng; Shao, Liming; Li, Tianshui; Lü, Fan; He, Pinjing

2014-02-01

466

Multistage treatment wetland for treatment of reject waters from digested sludge dewatering.  

PubMed

The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75-80%, biochemical oxygen demand (BOD) 82.2-95.5% and total nitrogen 78.7-93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal. PMID:24056417

Gajewska, M; Obarska-Pempkowiak, H

2013-01-01

467

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

468

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

469

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 searc