These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Dewatering of fine coal  

SciTech Connect

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

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

1995-10-01

2

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

3

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

4

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

5

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...

6

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

7

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

8

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

9

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

10

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

11

Dewatering with SolidCoat Technology  

E-print Network

11.11.2014 1 Dewatering with SolidCoat Technology SolidCoat Technology Introduction to Solid dewatering elements bearing in mind: ­ Effective dewatering ­ Energy savings ­ Gentle fabric contact ­ High-quality end product SolidCoat dewatering elements employed in current paper machine solutions include: ­ Vacu

Das, Suman

12

Thermal dryer dewaters solids  

SciTech Connect

Solids incineration is traditionally an energy-intensive solids handling process at wastewater treatment plants. To reduce energy costs, the Buffalo (N.Y.) Sewer Authority has added an indirect thermal dryer to its treatment plant to dewater solids before incineration. In the first 3 months of operation, the authority reduced its solids inventory from 634,400 to 227,300 kg. Solids processed in the plant`s multiple-hearth incinerators varied from 11 to 12.75 wet Mg/hr at feed concentrations averaging 21% total solids. And, the dryer was operated with less than 5% downtime. The cost of this indirect thermal dryer system, including construction and equipment, was $995,000. 1 fig., 2 tabs.

DiMascio, F.J. [Buffalo Sewer Authority, NY (United States); Burrowes, P.A. [Parsons, Brinkerhoff, Gore & Storrie, North York, Ontario (Canada)

1993-09-01

13

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

14

PILOT INVESTIGATION OF SECONDARY SLUDGE DEWATERING ALTERNATIVES  

EPA Science Inventory

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

15

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

16

Dewatering of fine coal using hyperbaric filter  

SciTech Connect

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

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

1995-12-31

17

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

18

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

19

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...

20

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...

21

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

22

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

23

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

24

Sequential polymer dosing for effective dewatering of ATAD sludges  

Microsoft Academic Search

Dewatering problems associated with the sludge from autothermal thermophilic aerobic digestion (ATAD) of sludge, result in large chemical conditioning costs for effective dewatering. A variety of chemical conditioners were used to improve dewatering, but none of them were able to dewater the sludge as desired at acceptable conditioning doses. It was found that during the digestion process, chemical precipitation of

Saurabh Agarwal; Mohammad Abu-Orf; John T. Novak

2005-01-01

25

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

26

Salmonid redd dewatering: What do we know  

SciTech Connect

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

Becker, C D; Neitzel, D A

1983-11-01

27

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

28

Developments in coal dewatering in Australia  

SciTech Connect

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

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

1995-10-01

29

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 ...

30

Solution dewatering with concomitant ion removal  

SciTech Connect

One of the biggest needs in the separations and waste handling and reduction area is a method for dewatering ion-containing solutions. Unexpectedly, it has been found that phosphazene polymers can discriminate between water and metal ions, allowing water to pass through the membrane while retaining the ions. This unexpected result, along with the inherent chemical and thermal stability of the phosphazene polymers, yields a powerful tool for separating and dewatering metal-ion-containing solutions.

Peterson, Eric S.; Marshall, Douglas W.; Stone, Mark L.

2003-08-05

31

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

32

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

33

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

34

Supplementary Material for: "Macroinvertebrate community responses to a dewatering  

E-print Network

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

Doyle, Martin

35

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

36

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

37

Dewatering and remediation of contaminated dredged sediments  

Microsoft Academic Search

Dewatering and remediation of contaminated sediments is a critical issue in the management of dredged sediments because of limited space in confined disposal facilities (CDFs). Many of the contaminants in sediments require an aerobic environment for degradation, presenting a problem for bioremediation as these sediments exist under anaerobic conditions. A three-year study was conducted to test plant species for their

Katy Wren Euliss

2005-01-01

38

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

39

CHEMICAL PRIMARY SLUDGE THICKENING AND DEWATERING  

EPA Science Inventory

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

40

DEWATERING MUNICIPAL SEWAGE SLUDGES SELECTING A PROCESS  

EPA Science Inventory

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

41

Vibration screens for dewatering of minerals -- Theory and practice  

SciTech Connect

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

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

1995-12-31

42

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

43

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

44

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

45

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

46

Dewatering of activated sludge by Fenton's reagent  

Microsoft Academic Search

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

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

2003-01-01

47

Electroacoustic dewatering of food and other suspensions  

SciTech Connect

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

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

1989-05-31

48

Sequential polymer dosing for effective dewatering of ATAD sludges.  

PubMed

Dewatering problems associated with the sludge from autothermal thermophilic aerobic digestion (ATAD) of sludge, result in large chemical conditioning costs for effective dewatering. A variety of chemical conditioners were used to improve dewatering, but none of them were able to dewater the sludge as desired at acceptable conditioning doses. It was found that during the digestion process, chemical precipitation of divalent cations occurred. Some of the ATAD sludge colloids were found to have a positive zeta potential and these were thought to be the precipitated divalent cations. Sequential polymer dosing using either iron or cationic polymer, followed by anionic polymer, was found to improve dewatering. The use of anionic polymer is essential and allows the use of smaller amounts of iron or cationic polymer for effective dewatering. The use of the less expensive anionic polymer along with cationic polymers has the potential to make the use of the ATAD process more economical. PMID:15862329

Agarwal, Saurabh; Abu-Orf, Mohammad; Novak, John T

2005-04-01

49

Dredging and dewatering sediment containing hazardous and toxic materials  

SciTech Connect

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

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

1996-12-31

50

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

51

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

Code of Federal Regulations, 2014 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...

2014-10-01

52

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

53

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

54

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

55

Improved FGD dewatering process cuts solid wastes  

SciTech Connect

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

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

2009-08-15

56

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

57

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

58

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

Code of Federal Regulations, 2014 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...

2014-10-01

59

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

E-print Network

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

US Army Corps of Engineers

60

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

Code of Federal Regulations, 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

61

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

62

Predicting the moisture content of coals dewatered by vacuum filters  

SciTech Connect

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

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

1995-12-31

63

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

64

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

65

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

66

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

67

Pressure, centrifugal, and electrically assisted dewatering of coal  

SciTech Connect

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

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

1995-10-01

68

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

69

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

70

Ultrafine coal single stage dewatering and briquetting process  

SciTech Connect

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

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

1995-12-31

71

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

72

Field Guide to Construction Site Dewatering  

E-print Network

Transportation (Caltrans). The manual establishes uniform policies and guidelines to support dewatering operations on construction sites. It is neither intended as, nor does it establish a legal standard for those functions. The guidelines herein are for the information and guidance of the resident engineers and employees of the Department and its contractors. The guidance and instructions published herein are subject to amendment as conditions and experience warrant. The loose-leaf form of this manual was chosen because it facilitates change and expansion. New or amended policies or procedures will be issued as additional or replacement pages in the format of this manual. Special situations may warrant variation from the published policies and guidelines. This manual is not a textbook or a substitute for engineering or technical knowledge, experience or judgment. The mention of any specific commercial product, processes or service in this manual is not to be construed as either an actual or implied endorsement, recommendation or warranty thereof by Caltrans. Caltrans makes no representation or warranty of any kind, whether expressed or implied, concerning products or processes discussed in this manual and assumes no liability therefrom.

unknown authors

73

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

E-print Network

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

Kwak, Thomas J.

74

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

E-print Network

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

Chen, Keh-Hsun

75

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

76

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

77

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

78

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

79

Heat inactivation of enteric viruses in dewatered wastewater sludge.  

PubMed Central

The effect of moisture content on the rates of heat inactivation of enteric viruses in wastewater sludge was determined. The protective effect of raw sludge on poliovirus previously observed (R. L. Ward, C. S. Ashley, and R. H. Moseley, Appl. Environ. Microbiol. 32:339--346, 1976) was found to be greatly enhanced in sludge dewatered by evaporation. Other enteroviruses responded in a similar fashion. This effect did not appear to be due merely to the state of dryness of the sludge samples because in humus-deficient soil, a relatively inert material, the rate of poliovirus inactivation by heat was not significantly altered through dewatering. Instead, this effect appeared to have been caused by protective substances in the sludge, such as detergents, which are concentrated through dewatering. As reported previously (R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol. 34:681-688, 1977; R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol 36:889--897, 1978) raw sludge is not protective of reovirus, but, instead, the ionic detergents in sludge cause the rate of heat inactivation of this virus to be accelerated. Dewatering of sludge, however, was found to partially reverse this virucidal effect. Evidence is presented indicating that this reversal is caused by an unidentified protective substance in sludge also concentrated through dewatering. Finally, it was shown that the effects of raw sludge on heat inactivation of poliovirus and reovirus are greatly reduced by composting, a result that correlated with the degradation of detergents. PMID:216309

Ward, R L; Ashley, C S

1978-01-01

80

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

PubMed

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

Tunçal, Tolga

2011-05-01

81

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

82

Dewatering of coalbed methane wells with hydraulic gas pump  

SciTech Connect

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

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

1995-12-31

83

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

84

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

E-print Network

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

Henderson, Gideon

85

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

E-print Network

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

Kwak, Thomas J.

86

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

E-print Network

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

87

Analytic solution to the Martinez dewatering equations for roll gap formers  

E-print Network

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

Dodson, C.T.J.

88

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

E-print Network

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

Li, Perry Y.

89

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

E-print Network

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

Paris-Sud XI, Université de

90

Effect of Processing Mode on Trace Elements in Dewatered Sludge Products Brian K. Richards1  

E-print Network

Effect of Processing Mode on Trace Elements in Dewatered Sludge Products Brian K. Richards1 *, John compared. A single day's production of dewatered anaerobically-digested sludge (Syracuse, NY) was used essentially constant during dewatered sludge production with mean values (mg kg-1 total solids) of 5.6 Cd, 10

Walter, M.Todd

91

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

E-print Network

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

Kamat, Vineet R.

92

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

93

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

E-print Network

Inferred pore pressures at the Costa Rica subduction zone: implications for dewatering processes a direct measure of the rate and magnitude of sediment dewatering. Laboratory consolidation tests indicate use a simple model of fluid flow to demonstrate that dewatering of the underthrust sediments can occur

Fisher, Andrew

94

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

95

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

96

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

E-print Network

Genesis of dewatering structures and its implications for melt-out till identification Anders E-mail: carlsand@geo.oregonstate.edu ABSTRACT. Dewatering structures are a common feature used to identify melt the conditions under which melt-out till can be deposited without forming dewatering structures, I use

Carlson, Anders

97

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

E-print Network

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

98

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

E-print Network

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

Mukhtar, Saqib

99

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

E-print Network

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

Aydilek, Ahmet

100

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

101

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

102

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

103

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

104

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

105

A parametric study of dewatering of fine coal  

SciTech Connect

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

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

1996-12-31

106

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

107

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

108

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

109

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

110

Multi-force dewatering for magnetic waste materials  

Microsoft Academic Search

The ability to effectively dewater many industrial wastes is often a severe limitation in their recycling or disposal. Wastes from steel-making frequently fall into this category, and there are numerous steel plants, and allied industries, operating around the world producing large quantities of such waste. Many of the waste slurries from the steel industry are characterized by their low solids

J. L. Watson; P. L. Gardner

1995-01-01

111

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

112

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

113

Dewatering/reconstitution of fine clean coal slurry  

SciTech Connect

This paper describes an innovative approach for in-situ dewatering/hardening of fine clean coal slurry. The technique uses various fibrous waste materials added to coal slurry before dewatering process to obtain a dewatered product with lower cake moisture as well as sufficient strength to facilitate its handling. The study was conducted on both vacuum and pressure bench scale apparatus for dewatering and reconstitution of fine clean coal slurry. The fibrous waste materials investigated included plastic, newspaper, carpet mixed office waste, raw paper and wood fibers. The effects of several surfactants and flocculants on final moisture content of the filter cakes were also determined. The results showed that using the vacuum filter, addition of 10 Kg/ton of mixed office waste fibers decreased the filter cake moisture from 41.3 to 34.8% by weight, a 16% moisture reduction over the baseline data. The addition of fibers showed moisture reduction as well as large improvement in solids loading as much as 2 fold over those observed in the absence of fibers. For the pressure filtration, the addition of plastic fibers provided a filter cake containing 21.4% moisture which is about 2.1% lower than that of the untreated filter cake. The average final cake moisture reduction of 1.5% was achieved for the test fibers using the pressure filter. It was also found that fiber addition in pressure filtration led to shorter cake formation time thus increasing the filtration rate of the coal slurry. The hardening properties of the dried filter cakes with fibers improved significantly such that the cake compression strength improved from 0 to 4.5 Kg/cm{sup 2}, impact resistance from 0 to 4, abrasion resistance from 0 to 70%, and dust reduction efficiency from 0 to 75%.

Sung, D.J.; Shao, X.; Parekh, B.K.

1998-07-01

114

Dewatering/reconstitution of fine clean coal slurry  

SciTech Connect

This paper describes an innovative approach for in-situ dewatering/hardening of fine clean coal slurry. The technique uses various fibrous waste materials added to coal slurry before dewatering process to obtain a dewatered product with lower cake moisture as well as sufficient strength to facilitate its handling. The study was conducted on both vacuum and pressure bench scale apparatus for dewatering and reconstitution of fine clean coal slurry. The fibrous waste materials investigated included plastic, newspaper, carpet, mixed office waste, raw paper and wood fibers. The effects of several surfactants and flocculants; on final moisture content of the filter cakes were also determined. The results showed that using the vacuum filter, addition of 10 Kg/ton of mixed office waste fibers decreased the filter cake moisture from 41.3 to 34.8 percent by weight, a 16 percent moisture reduction over the baseline data. The addition of fibers showed moisture reduction as well as large improvement in solids loading as much as 2 fold over those observed in the absence of fibers. For the pressure filtration, the addition of plastic fibers provided a filter cake containing 21.4 percent moisture which is about 2.1 percent lower than that of the untreated filter cake. The average final cake moisture reduction of 1.5 percent was achieved for the tested fibers using the pressure filter. It was also found that fiber addition in pressure filtration led to shorter cake formation time thus increasing the filtration rate of the coal slurry. The hardening properties of the dried filter cakes with fibers improved significantly such that the cake compression strength improved from 0 to 4.5 Kg/cm{sup 2}, impact resistance from 0 to 4, abrasion resistance from 0 to 70 percent, and dust reduction efficiency from 0 to 75 percent.

Sung, D.J.; Shao, X.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States)

1998-04-01

115

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

116

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

117

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

118

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

119

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

120

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

121

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

NASA Astrophysics Data System (ADS)

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.

1989-07-01

122

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

123

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

124

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

125

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

126

New coal dewatering technology turns sludge to powder  

SciTech Connect

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

NONE

2009-03-15

127

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

128

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

129

Phosphorus partitioning in co-dewatering biosolids and water treatment residuals.  

PubMed

Stabilization and dewatering methods for wastewater solids determine the concentration and nature of phosphorus (P) in biosolids and in-plant sidestreams recycled to the liquid treatment facility. Because water treatment residuals (WTR) exhibit strong immobilization of soluble P, this study evaluated the impact of co-dewatering WTR and biosolids on the P partitioning during dewatering and the environmental lability of biosolids-P measured by water-extractable P (WEP). Overall, P progressively partitioned into the water-insoluble particulate-bound form in dewatered cake with increasing blending ratio (BR) - defined as the dry mass ratio of WTR to biosolids. The reject water total P (TP) content from dewatering biosolids alone (250 mg L?¹) was reduced to 60 mg L?¹ for a BR = 1.5. Polymer addition resulted in statistically (? = 0.05) lower reject liquid TP, suggesting the cationic polyelectrolyte contributed to P binding. The WEP of the dewatered cake (?20% solids) dropped from 2.36 g kg?¹ (biosolids only) to ?0.14 g kg?¹ for BR = 1.5, meaning the P in land-applied co-processed cake is less susceptible to solubilization by surface runoff compared to unamended biosolids. Co-dewatering can reduce P in return flows and fix P in the dewatered solids in a form less prone to off-site migration following land application. PMID:25098870

Elliott, Herschel A; Taylor, Malcolm

2014-01-01

130

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

E-print Network

is preferred over other dewatering technologies as it has lower energy consumption. However, a microalgal feed concentration of 10 - 40 g dry wt. /L is required prior to dewatering on a belt filter system. The objective of this study was to investigate...

Sandip, Anjali

2014-05-31

131

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

Microsoft Academic Search

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

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

2005-01-01

132

DEWATERING 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...

133

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 ...

134

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

135

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

136

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

Microsoft Academic Search

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

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

2004-01-01

137

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

SciTech Connect

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

Not Available

1993-07-01

138

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

139

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

140

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

Microsoft Academic Search

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

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

1997-01-01

141

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

142

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...

143

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 ...

144

Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids  

Microsoft Academic Search

Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients,

J. W. Worley; T. M. Bass; P. F. Vendrell

2008-01-01

145

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

E-print Network

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

Lorenzen, Kai

146

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

E-print Network

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

Long, Bernard

147

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

148

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

149

Landward-dipping reflectors in accretionary wedges: active dewatering conduits  

SciTech Connect

Landward-dipping seismic reflectors (LDRs) within the accretionary wedge at convergent plate margins have generally been interpreted as tilted-bedding or thrust-fault surfaces (e.g., Mexico, northern Japan). This interpretation accords with models in which trench-axis sediments are scraped off the descending plate to form a series of imbricate thrust sheets. However, intensely disturbed melanges with a regionally extensive landward-dipping foliation are found beneath slope sediments in many ancient and active subduction complexes. This observation, combined with the fact that large volumes of fluid are released during dewatering of subducting and previously accreted sediments, leads to the proposal that some of the seismic reflectors are porous, laterally extensive fractureways filled with dewatering fluids derived from deeper underthrust water-rich sediments. These fractureways trend subparallel to the regional foliation of the accreted melange wedge. The contrast in acoustic impedance between the high-porosity fluid-filled fractureways and the melange wall rocks is enhanced whenever methane and/or carbon dioxide exsolve from rising waters. Ancient LDRs may be recognized where mineralized veins trend subparallel to the regional foliation of melange belts generated during subduction accretion. 42 references, 2 figures.

Cloos, M.

1984-09-01

150

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

SciTech Connect

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

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

1995-11-01

151

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.

2011-06-01

152

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

153

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

154

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

155

To enhance the dewatering of vacuum filter by adding surfactant reagent  

SciTech Connect

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

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

1997-12-31

156

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

157

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

SciTech Connect

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

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

1998-04-01

158

Low Cost, Low Energy, Method of Dewatering Cultures of the Green Microalgae Nannochloris oculata: Electrocoagulation  

E-print Network

; a low cost, low energy method of dewatering cultures of microalgae. The objectives of this research focus on recognizing parameters that influence the overall efficiency of the process, effective electrode materials, and finally directional...

Murdock, Jared

2014-05-01

159

Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogenproduction.  

PubMed

The increasing sludge generated in wastewater treatment plants poses a threat to the environment. Based on the traditional processes, sludge dewatered by usual methods was further dewatered by hydraulic compression and the filtrate released was treated by anaerobic fermentation. The difficulties in sludge dewatering were associated with the existence of sludge flocs or colloidal materials. A suitable CaO dosage of 125 mg/g dry sludge (DS) could further decrease the moisture content of sludge from 82.4 to 50.9 %. The filtrate from the dewatering procedure was a potential substrate for biohydrogen production. Adding zero-valent iron (ZVI) into the anaerobic system improved the biohydrogen yield by 20 %, and the COD removal rate was lifted by 10 % as well. Meanwhile, the sludge morphology and microbial community were altered. The novel method could greatly reduce the sludge volume and successfully treated filtrate along with the conversion of organics into biohydrogen. PMID:25192669

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

2015-02-01

160

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

SciTech Connect

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

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

1994-12-31

161

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

Microsoft Academic Search

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

J. Y. Lai; J. C. Liu

162

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

163

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

164

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

165

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

166

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

167

Comparing alkaline and thermal disintegration characteristics for mechanically dewatered sludge.  

PubMed

Thermal drying is one of the advanced technologies ultimately providing an alternative method of sludge disposal. In this study, the drying kinetics of mechanically dewatered sludge (MDS) after alkaline and thermal disintegration have been studied. In addition, the effect of total organic carbon (TOC) on specific resistance to filtration and sludge bound water content were also investigated on freshly collected sludge samples. The combined effect of pH and TOC on the thermal sludge drying rate for MDS was modelled using the two-factorial experimental design method. Statistical assessment of the obtained results proposed that sludge drying potential has increased exponentially for both increasing temperature and lime dosage. Execution of curve fitting algorithms also implied that drying profiles for raw and alkaline-disintegrated sludge were well fitted to the Henderson and Pabis model. The activation energy of MDS decreased from 28.716 to 11.390 kJ mol(-1) after disintegration. Consequently, the unit power requirement for thermal drying decreased remarkably from 706 to 281 W g(-1) H2O. PMID:22329149

Tunçal, Tolga

2011-10-01

168

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

169

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

170

Thermal conductivity characteristics of dewatered sewage sludge by thermal hydrolysis reaction.  

PubMed

The purpose of this study is to quantify the thermal conductivity of sewage sludge related to reaction temperature for the optimal design of a thermal hydrolysis reactor. We continuously quantified the thermal conductivity of dewatered sludge related to the reaction temperature. As the reaction temperature increased, the dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. Therefore, the bound water in the sludge cells comes out as free water, which changes the dewatered sludge from a solid phase to slurry in a liquid phase. As a result, the thermal conductivity of the sludge was more than 2.64 times lower than that of the water at 20. However, above 200, it became 0.704 W/m* degrees C, which is about 4% higher than that of water. As a result, the change in physical properties due to thermal hydrolysis appears to be an important factor for heat transfer efficiency. Implications: The thermal conductivity of dewatered sludge is an important factor the optimal design of a thermal hydrolysis reactor. The dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. The liquid phase slurry has a higher thermal conductivity than pure water. PMID:25562934

Song, Hyoung Woon; Park, Keum Joo; Han, Seong Kuk; Jung, Hee Suk

2014-12-01

171

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

SciTech Connect

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

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

1998-04-01

172

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

173

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

SciTech Connect

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

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

1995-08-01

174

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

175

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

176

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

177

Plant selection for dewatering and reclamation of tailings  

SciTech Connect

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

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

1998-12-31

178

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

179

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

180

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

181

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

182

Effect of polyphosphate and naphthalene sulfonate formaldehyde condensate on the rheological properties of dewatered tailings and cemented paste backfill  

Microsoft Academic Search

The rheological properties of dewatered tailings and cemented paste backfill have been measured and subsequently altered using polymeric dispersants. Polyphosphate and naphthalene sulfonate formaldehyde condensate (NSF) were selected as potential candidates to reduce the yield stress (?B) of the two slurries. Adsorption isotherms, acoustophoresis, and rheology measurements indicate that the polymers adsorb onto the dewatered tailings, causing an increase in

L. Huynh; D. A. Beattie; D. Fornasiero; J. Ralston

2006-01-01

183

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.

184

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

185

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

186

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

187

Dewatering as a non-toxic control of nuisance midge larvae in algal wastewater treatment floways.  

PubMed

Attached-algae floways have tremendous potential for use in wastewater treatment because natural algal communities show high nutrient removal efficiencies, have low operating costs, and are easy to maintain. Algal wastewater floways may also serve as a sustainable option for producing renewable energy because algae grow rapidly, are easily harvested, and can serve as a source of biomass for biofuel. However, pests such as chironomids (Diptera) colonize open channel periphyton floways and their larvae damage the biofilms. While pesticides can control midge larvae, little information is known about alternative, non-toxic controls. This study examined the effectiveness of periodic, short-term dewatering (4 hours every 9 days) on midge abundance and periphyton growth in 16 recirculating, outdoor floways (3 m long, 0.1 m wide). We compared midge abundance and algal accumulation (chlorophyll a, b, c, and pheophytin) among control (n = 8) and dewatered (n = 8) floways filled with secondarily treated wastewater (27 days, 10 hours of daylight). Dewatered flumes had 42% fewer midges and 28-49% lower algal productivity (as measured by chlorophyll a, b, c, and pheophytin pigments). Chlorophyll a production rates averaged (±1 SD) 0.5 ± 0.2 ?g/cm(2)/day in control floways compared to 0.3 ± 0.1 ?g/cm(2)/day dewatered floways. Short-term dewatering effectively reduced midges but also damaged periphyton. To maximize the recovery of periphyton biomass, operators should harvest periphyton from floways during dewatering events before periphyton is damaged by desiccation or direct exposure to sunlight. PMID:25607663

Keller, Troy A; Husted, Emily M

2015-01-01

188

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

D. M. Saffer; E. A. Silver; A. T. Fisher; H. Tobin; K. Moran

2000-01-01

189

Formation of Valles Marineris and Associated Outlfow Channels by Catastrophic Dewatering of Evaporite Deposits  

Microsoft Academic Search

Geological mapping based on topographic analysis of Mars Orbiter Laser Altimeter (MOLA) data, together with photointerpretation of Mars Orbiter Camera (MOC) images, and thermodynamic and heat-flow considerations lead to a new hypothesis for the formation of Valles Marineris and the associated outflow channels through catastrophic dewatering of ancient evaporite deposits. MOLA transects across Valles Marineris reveal that the valley is

D. R. Montgomery; A. Gillespie

2004-01-01

190

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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 was evaluated. Emergence traps were deployed 19 May-20 Oct 2009 (22 wk) and 27 May-18 Nov 2010 (25 wk). A t...

191

Geotextile filtration performance for lagoon sludges and liquid animal manures dewatering  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maintenance and control of liquid levels in anaerobic lagoons and storage ponds require liquid-solid separation as a pretreatment and periodic removal of accumulated sludges. Until local options become available, sludges can be contained, dewatered, and stored using geotextile filtration. We used a ...

192

Effects of different sludge disintegration methods on sludge moisture distribution and dewatering performance.  

PubMed

A key step in sludge treatment is sludge dewatering. However, activated sludge is generally very difficult to be dewatered. Sludge dewatering performance is largely affected by the sludge moisture distribution. Sludge disintegration can destroy the sludge structure and cell wall, so as change the sludge floc structure and moisture distribution, thus affecting the dewatering performance of sludge. In this article, the disintegration methods were ultrasound treatment, K2FeO4 oxidation and KMnO4 oxidation. The degree of disintegration (DDCOD), sludge moisture distribution and the final water content of sludge cake after centrifuging were measured. Results showed that three disintegration methods were all effective, and K2FeO4 oxidation was more efficient than KMnO4 oxidation. The content of free water increased obviously with K2FeO4 and KMnO4 oxidations, while it decreased with ultrasound treatment. The changes of free water and interstitial water were in the opposite trend. The content of bounding water decreased with K2FeO4 oxidation, and increased slightly with KMnO4 oxidation, while it increased obviously with ultrasound treatment. The water content of sludge cake after centrifuging decreased with K2FeO4 oxidation, and did not changed with KMnO4 oxidation, but increased obviously with ultrasound treatment. In summary, ultrasound treatment deteriorated the sludge dewaterability, while K2FeO4 and KMnO4 oxidation improved the sludge dewaterability. PMID:25662234

Jin, Lingyun; Zhang, Guangming; Zheng, Xiang

2015-02-01

193

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

194

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

195

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

196

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

197

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

198

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

PubMed

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

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

2015-01-01

199

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

Microsoft Academic Search

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

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

2000-01-01

200

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

201

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...

202

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

203

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

204

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 ...

205

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

E-print Network

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

Housen, Bernie

206

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

Microsoft Academic Search

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

Xu Dayong

2010-01-01

207

Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids.  

PubMed

Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients, especially phosphorus into the solid phase. Chemically amended slurry was pumped from the lagoon into the tube with the filtered liquid seeping from the tube and returning to the lagoon. Each tube was filled five to six times at 2-5-day intervals, and then allowed to dewater for 2 weeks before sampling the solid fraction in the tube. Separation efficiency improved from 79% to 99% for phosphorous and from 92% to 100% for organic nitrogen with chemical amendment. Time required for dewatering was significantly reduced by chemical amendment. Cost for the tube was approximately $10/m(3) of recovered solids with no chemical amendment and cost including the chemicals was approximately $14/m(3) of recovered solids. PMID:17945490

Worley, J W; Bass, T M; Vendrell, P F

2008-07-01

208

Centrifugal dewatering and reconstitution of fine coal by the GranuFlow Process  

SciTech Connect

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

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

1997-12-31

209

Evaluation of thickening and dewatering characteristics of SRC-I wastewater treatment sludges. Final technical report  

SciTech Connect

The SRC-I Demonstration Plant in Newman, Kentucky, will generate several different sludges as a result of providing extensive wastewater treatment. Because construction of this plant has been postponed indefinitely, there has been an opportunity to generate additional data pertinent to waste treatment. Accordingly, this report presents the results of a study on the thickening and dewatering characteristics of several of the wastewater treatment sludges. The study included: evaluation of chemical conditioning agents; aerobic digestion of biological sludges; gravity thickening; and the relative effectiveness of dewatering by centrifuge, vacuum filter, belt filter, and pressure filter. Sludges were tested individually and in combination. The results indicated that the biological sludge could be best dewatered by pressure filtration. The chemical sludges should be combined prior to dewatering, which should be provided by a belt filter. The tar acid sludge will be kept separate, due to its low pH, and ultimate disposal will be by incineration. The tar acid sludge was more concentrated than had been expected. As a result, thickening, rather than centrifuging, is the recommended treatment for this sludge. All sludges were tested for leachate toxicity by the extraction procedure method. The results were negative, indicating the sludges are non-hazardous in heavy metal concentrations, according to RCRA classification. The test results have identified design changes for the proposed wastewater treatment facilities.

Not Available

1984-05-01

210

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

Microsoft Academic Search

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

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

2007-01-01

211

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

212

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

213

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

E-print Network

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

Mukhtar, Saqib; Wagner, Kevin; Gregory, Lucas

214

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

215

Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon-aluminum-iron-starch flocculant.  

PubMed

Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon-aluminum-ferric-starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0-11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications. PMID:25497034

Lin, Qintie; Peng, Huanlong; Zhong, Songxiong; Xiang, Jiangxin

2015-03-21

216

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

217

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

218

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

219

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

SciTech Connect

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

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

1993-11-09

220

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

PubMed Central

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

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

221

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

222

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

223

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

224

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

225

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

SciTech Connect

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

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

1997-07-01

226

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

227

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

228

Vacuum dewatering and horizontal drainage blankets: a method for layered soil reclamation  

Microsoft Academic Search

This paper reports a study of vacuum dewatering using horizontal geosynthetic drainage blankets as a more economical and effective\\u000a method of reclamation using layers of dredged material. Laboratory tests were carried out on samples from two different sites\\u000a in eastern China, Qingdao City and Lianyungang City. The study showed that the method is feasible and results in a significant\\u000a time

L. H. Li; Q. Wang; N. X. Wang; J. P. Wang

2009-01-01

229

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

230

Characteristics and kinetics of phosphate adsorption on dewatered ferric-alum residuals  

Microsoft Academic Search

The characteristics and kinetics of phosphate (P) adsorption on dewatered ferric-alum water treatment residuals (Fe-Al-WTRs) have been investigated. The existence of both aluminum (Al) and iron (Fe) in the residuals can result in significantly high P adsorption capacities. The P adsorption kinetics of Fe-Al-WTRs exhibited an initial rapid phase, followed by a slower phase. This could be described by three

Changhui Wang; Wei Guo; Binghui Tian; Yuansheng Pei; Kejiang Zhang

2011-01-01

231

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

232

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

233

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

234

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

235

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

236

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

237

Hydrothermal treatment coupled with mechanical expression at increased temperature for excess sludge dewatering: the dewatering performance and the characteristics of products.  

PubMed

Hydrothermal treatment coupled with mechanical expression at increased temperature in two separate cells respectively is effective for the dewatering of excess sludge with low energy consumption. The objectives of this study were to evaluate the dewatering performance and the characteristics of obtained products (hydrothermal sludge, hydrochar and filtrate). The results showed that harsher hydrothermal treatment (temperature from 120 to 210 °C and residence time from 10 to 90 min) led to greater water removal (from 7.44 to 96.64% reduction of total water) and mechanical pressure became less significant as it increased. The whole expression stage was completely described by the modified Terzaghi-Voigt rheological model. The role of tertiary consolidation stage in the water removal was reduced with hydrothermal treatment being stronger. The hydrothermal treatment is mainly a devolatilization process. The observed changes in H/C and O/C for hydrothermal sludge suggested dehydration was the major reaction mechanism and decarboxylation only occurred significantly at higher temperature. The higher heating value correlated well with carbon content of sludge, which was increased by 4.8% for hydrothermal sludge at 210 °C for 60 min and significantly decreased by 15.4% for hydrochar after 6.0 MPa for 20 min. The solubilization and decomposition of proteins, polysaccharides and DNA were determined to be temperature and residence time dependent. The improvement of dewaterability was closely correlated to the variation of these biopolymers. The filtrates collected above 150 °C were found to be acidic. The increase of humic substances and the melanoidins formed by Maillard reaction were largely responsible for the filtrate color. PMID:25462737

Wang, Liping; Li, Aimin

2015-01-01

238

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

239

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

240

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. PMID:24878582

Pan, Chengyi

2014-01-01

241

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

242

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

243

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

244

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

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

245

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

246

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

247

Chitosan use in chemical conditioning for dewatering municipal-activated sludge.  

PubMed

This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl3). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl3 and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl3 allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10(12), 0.932 × 10(12) and 2 × 10(12) m/kg for Sed CF802, chitosan and FeCl3 respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl3. PMID:25812088

Zemmouri, H; Mameri, N; Lounici, H

2015-01-01

248

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

249

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

PubMed

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

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

2014-10-01

250

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

251

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

252

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

253

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

254

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

255

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

256

Septage dewatering in vertical-flow constructed wetlands located in the tropics.  

PubMed

Constructed wetlands (CWs) have been proven to be an effective low-cost treatment system, which utilizes the interactions of emergent plants and microorganisms in the removal of pollutants. CWs for wastewater treatment are ndrmally designed and operated in horizontal-flow patterns, namely, free-water surface or subsurface flow, while a vertical-flow operation is normally used to treat sludge or septage having high solid contents. In this study, three pilot-scale CW beds, each with a surface area of 25 m2, having 65 cm sand-gravel substrata, supported by ventilated-drainage system and planting with narrow-leave cattails (Typha augustifolia), were fed with septage collected from Bangkok city, Thailand. To operate in a vertical-flow mode, the septage was uniformly distributed on the surface of the CW units. During the first year of operation, the CWs were operated at the solid loading rates (SLR) and application frequencies of, respectively, 80-500 kg total solid (TS)/m2 x yr and 1-2 times weekly. It was found that the SLR of 250 kg TS/m2 x yr resulted in the highest TS, total chemical oxygen demand (TCOD) and total Kjeldahl nitrogen (TKN) removal of 80, 96 and 92%, respectively. The TS contents of the dewatered septage on the CW beds were increased from 1-2% to 30-60% within an operation cycle. Because of the vertical-flow mode of operation and with the effectiveness of the ventilation pipes, there were high degrees of nitrification occurring in the CW beds. The nitrate (NO3) contents in the CW percolate were 180-250 mg/L, while the raw septage had NO3 contents less than 10 mg/L. Due to rapid flow-through of the percolates, there was little liquid retained in the CW beds, causing the cattail plants to wilt, especially during the dry season. To reduce the wilting effects, the operating strategies in the second year were modified by ponding the percolate in the CW beds for periods of 2 and 6 days prior to discharge. This operating strategy was found beneficial not only for mitigating plant wilting, but also for increasing N removal through enhanced denitrification activities in the CW beds. During these 2 year operations, the dewatered septage was not removed from the CW beds and no adverse effects on the septage dewatering efficiency were observed. PMID:11547982

Koottatep, T; Polprasert, C; Oanh, N T; Heinss, U; Montangero, A; Strauss, M

2001-01-01

257

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

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

258

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

PubMed

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

Wang, Liping; Zhang, Lei; Li, Aimin

2014-11-15

259

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

260

Dewatering equipment recommendations for the solids/liquid separation project at Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee  

SciTech Connect

The final closure of Waste Area Grouping (WAG) 6 at Oak Ridge National Laboratory will include the plugging and abandonment of many existing wells and boreholes and the installation of diversion trenches for groundwater control. These activities will generate soil that must be dewatered before it can be disposed of. Three different types of dewatering equipment{emdash}rotary vacuum drum filters, automatic discharge pressure filters, and centrifuges{emdash}have been evaluated to assess their suitability for the WAG 6 project. Because of its lower cost and minimal prescreening requirements, it is recommended that a centrifuge be used to dewater the WAG 6 soils.

Taylor, P.A.

1992-05-01

261

Dewatering equipment recommendations for the solids/liquid separation project at Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program  

SciTech Connect

The final closure of Waste Area Grouping (WAG) 6 at Oak Ridge National Laboratory will include the plugging and abandonment of many existing wells and boreholes and the installation of diversion trenches for groundwater control. These activities will generate soil that must be dewatered before it can be disposed of. Three different types of dewatering equipment{emdash}rotary vacuum drum filters, automatic discharge pressure filters, and centrifuges{emdash}have been evaluated to assess their suitability for the WAG 6 project. Because of its lower cost and minimal prescreening requirements, it is recommended that a centrifuge be used to dewater the WAG 6 soils.

Taylor, P.A.

1992-05-01

262

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

263

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. PMID:24459451

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

2013-01-01

264

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

265

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

266

Insights into the respective role of acidification and oxidation for enhancing anaerobic digested sludge dewatering performance with Fenton process.  

PubMed

Digested sludges generally exhibit poorer dewaterability than activated sludges. This study investigated the effects of acidification and oxidation on EPS properties and dewaterability of anaerobic digested sludge in Fenton treatment in order to unravel the underlying mechanism of sludge conditioning. The results indicated that sludge dewatering property was improved after acidification treatment. Meanwhile, fluorescence analysis revealed that the protein-like substances were effectively removed from sludge bulk after acidification treatment. Acidification and Fenton oxidation showed a significant synergetic effect in enhancing sludge dewatering process. Solubilization and decomposition of bound EPS occurred synchronously during Fenton conditioning. Oxidation process is very likely to play a more important role in sludge conditioning than Fenton coagulation. According to pilot test, Fenton treatment performed much better in cake moisture content reduction than chemical conditioning with traditional inorganic coagulants. Additionally, full-scale application of Fenton conditioning will not have detrimental effects on performance of wastewater treatment system. PMID:25656869

Zhang, Weijun; Yang, Peng; Yang, Xiaoyin; Chen, Zhan; Wang, Dongsheng

2015-04-01

267

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

268

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

269

Study on the pore structure and oxygen-containing functional groups devoting to the hydrophilic force of dewatered lignite  

NASA Astrophysics Data System (ADS)

In order to explore the water-holding capacity of dewatered lignite and the contribution of pore structure and oxygen-containing functional groups to it, a kind of typical Chinese lignite was dried under the atmosphere of nitrogen for different temperatures and times, and then was subjected to a process of moisture re-adsorption at the temperature of 25 °C and relative humidity of 75%. Nitrogen adsorption and chemical titration methods were used to examine the pore structure parameters and amounts of oxygen-containing functional groups, respectively. The results indicate that the porous structure and oxygen-containing functional groups in lignite are two main factors influencing the hydrophilicity of dewatered coal, and their contributions are varied with the change of drying conditions. The change of water-holding capacity of pore structure is primarily attributed to the shrinkage or collapse of macro- and mesoporous and it decreases with the increase of drying temperature. The oxygen-containing functional groups mainly include phenolic hydroxyl, carbonyl, carboxyl and methoxyl groups, and the order of their hydrophilicity is: carboxyl group > phenolic hydroxyl group > carbonyl group > methoxyl group. Moreover, the water-holding capacity for the same kind of oxygen-containing functional groups in dewatered coal obtained at different temperature is not a fixed one, their hydrophilic forces decrease with the increase of drying temperature. For the coal samples dried for 60 min under different temperature, the contribution of pore structure and oxygen-containing functional groups to the equilibrium moisture content (EMC) of dewatered lignite is: pore structure > phenolic hydroxyl group > carboxyl group > carbonyl group > methoxyl group. The contribution of total oxygen-containing functional groups to the EMC at below 280 °C is more obvious, and that of pore structure is the principal factor thereafter.

Zhang, Yanli; Jing, Xiaoxia; Jing, Kaige; Chang, Liping; Bao, Weiren

2015-01-01

270

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

271

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

272

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

273

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.

1996-10-01

274

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

275

Enhanced dewatering of sludge with the composite of bioflocculant MBFGA1 and P(AM-DMC) as a conditioner.  

PubMed

Bioflocculant MBFGA1 was investigated to be used as a conditioner for sludge dewatering, and the response surface methodology (RSM) was employed to study the enhancing performance of the dewatering process by the composite of MBFGA1 and poly(acrylamide [2-(methacryloyloxy)ethyl]-trimethylammonium chloride) (P(AM-DMC)). Results showed that dry solids (DS) and specific resistance to filtration (SRF) of sludge treated by MBFGA1 alone appeared as 21.7 % and 3.6?×?10(12) m kg(-1), respectively, which were much better than FeCl3, Al2(SO4)3, and polyaluminum chloride (PAC), but poorer than P(AM-DMC) in sludge dewatering. Apart from this, the optimized conditioning process for improving the dewaterability of the sludge conditioned by the composite is MBFGA1 of 1.4 g L(-1), P(AM-DMC) of 0.13 g L(-1), CaCl2 of 56.1 mg L(-1), pH value of 7.5, and agitation speed of 149 rpm. Under this optimal condition, DS and SRF appeared as 29.9 % and 2.2?×?10(12) m kg(-1), respectively. Thus, it is feasible and meaningful to enhance the dewaterability of the sludge by the compound uses of MBFGA1 and P(AM-DMC). PMID:25634018

Guo, Junyuan; Nengzi, Lichao; Zhao, Jing; Zhang, Yuzhe

2015-04-01

276

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

277

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

278

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

PubMed

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

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

2014-01-01

279

Effect of biodegradation on the consolidation properties of a dewatered municipal sewage sludge.  

PubMed

The effect of biodegradation on the consolidation characteristics of an anaerobically digested, dewatered municipal sewage sludge was studied. Maintained-load oedometer consolidation tests that included measurement of the pore fluid pressure response were conducted on moderately degraded sludge material and saturated bulk samples that had been stored under static conditions and allowed to anaerobically biodegrade further (simulating what would happen in an actual sewage sludge monofill or lagoon condition). Strongly degraded sludge material was produced after a storage period of 13 years at ambient temperatures of 5-15 degrees C, with the total volatile solids reducing from initially 70% to 55%. The sludge materials were highly compressible, although impermeable for practical purposes. Primary consolidation generally occurred very slowly, which was attributed to the microstructure of the solid phase, the composition and viscosity of the pore fluid, ongoing biodegradation and the high organic contents. The coefficient of primary consolidation values decreased from initially about 0.35m2/yr to 0.003-0.03m2/yr with increasing effective stress (sigmav'=3-100kPa). Initially, the strongly degraded sludge material was slightly more permeable, although both the moderately and strongly degraded materials became impermeable for practical purposes (k=10(-9)-10(-12)m/s) below about 650% and 450% water contents, respectively. Secondary compression became more dominant with increasing effective stress with a mean secondary compression index (Calphae) value of 0.9 measured for both the moderately and strongly degraded materials. PMID:17936608

O'Kelly, Brendan C

2008-01-01

280

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

PubMed

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

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

2014-09-01

281

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

282

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

283

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

284

[Optimization for phosphorous removal in thickening and dewatering sludge water by polyaluminum chloride].  

PubMed

Based on the comparison of phosphorous removal in sludge water and its supernatant by polyaluminum chloride (PAC), separate and combined effects of Al/P mole ratio, pH and mixing speed (MS) on phosphorus removal by PAC for the supernatant of thickening and dewatering sludge water were analyzed by the response surface methodology (RSM), and kinetics of phosphorous removal by PAC was also investigated. The results showed that direct addition of PAC into sludge water deteriorated its settling characteristics, and suspended solids in the sludge water could decrease the phosphorus removal efficiency. The RSM analysis results demonstrated that the effect of individual operation parameter on phosphorus removal was followed as the order of Al/P > pH > MS, and the optimal process parameters with phosphorus removal efficiency of 97.8% were Al/P = 2.49, pH = 8.3 and MS 398 r x min(-1), respectively. The verification experiment showed that the RSM model was valid and effective. Kinetic analysis illustrated that phosphorus removal by PAC was divided into two stages, a chemical precipitation and rapid adsorption stage, followed by a chemical precipitation stage that conformed to the second-order kinetics. PMID:25158503

Zhou, Zhen; Hu, Da-Long; Qiao, Wei-Min; Chen, Guan-Han; Jiang, Ling-Yan; Li, Zhen; Mai, Sui-Hai

2014-06-01

285

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

286

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

287

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

288

DOI: 10.1080/07373937.2011.602199 Electro-Kinetic Technology as a Low-Cost Method for Dewatering Food By-Product  

E-print Network

Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food byproducts that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This has brought about the necessity of dewatering food waste for any potential re-use for certain disposal options. A laboratory system for experimentally characterizing electro-kinetic dewatering of food by-products was evaluated. The bench scale system, which is an augmented filter press, was used to investigate the dewatering at constant voltage. Five food by-products (brewer’s spent grain, cauliflower trimmings, mango peel, orange peel, and melon peel) were studied. The results indicated that electro-kinetic dewatering combined with mechanical dewatering can reduce the percentage of moisture from 78 % to 71% for brewer’s spent grain, from 77 % to 68 % for orange peel, from

Sing K. Ng; Andrew Plunkett; Valentina Stojceska; Paul Ainsworth; John Lamont-black; David Russell

289

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

290

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

291

Ground penetrating radar response to water table drawdown and vadose zone dewatering  

NASA Astrophysics Data System (ADS)

Ground penetrating radar has become increasingly utilized in hydrogeology for studying both saturated and variably-saturated media. GPR reflections result from changes in the dielectric permittivity of the media. Sharp property contrasts produce higher reflection amplitudes relative to more gradational transitions. Because of the large decrease in dielectric permittivity, strong radar reflections are often generated at the transition from unsaturated to saturated media; the interval over which this transition occurs defines the transition zone (TZ). Increase in TZ thickness leads to lower GPR reflection amplitudes due to more gradual change in dielectric permittivity. Increase in TZ thickness is transient and may arise from dewatering of the unsaturated zone due to direct aquifer withdrawal (pumping) or changes in boundary conditions (river stage). When water table drawdown is rapid soil moisture decreases non-linearly with elevation above the water table which leads to a temporary increase in TZ thickness. When water table drawdown is slower, soil moisture in the vadose zone decreases at a more uniform rate and there is little extension of the TZ. Here we compare the results of time-lapse GPR monitoring of the water table during two separate drawdown events. The first is water table drawdown caused by pumping (9.1 cm drawdown over 2 hrs) and the second is water table drawdown caused by a step decrease in the adjacent river stage (5.4 cm drawdown over 8 hrs). GPR was able to successfully capture the water table drawdown in both tests and analysis of the water table reflection amplitude shows a greater decrease in reflection amplitude during the pumping test than during the river stage change suggesting that during the pumping test water table drawdown was rapid enough to cause significant TZ extension. We propose a method using correlation of synthetic GPR and hydrologic models to build a calibration curve for quantitative estimation of changes in TZ thickness.

Thoma, M. J.; Bradford, J. H.; Barrash, W.

2010-12-01

292

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

293

[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

294

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

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

295

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

PubMed

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

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

2009-09-01

296

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

NASA Astrophysics Data System (ADS)

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.

2013-02-01

297

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

298

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

299

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

300

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

301

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

302

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

303

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

304

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

305

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

PubMed

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

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

2014-10-01

306

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

307

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

308

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

309

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

310

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

311

The stability of aerobic granular sludge treating municipal sludge deep dewatering filtrate in a bench scale sequencing batch reactor.  

PubMed

Inoculated with mature aerobic granular sludge in a sequencing batch reactor, gradually increasing the proportion of municipal sludge deep dewatering filtrate in influent, aerobic granular sludge was domesticated after 84 days and maintained its structure during the operation. The domesticated AGS was yellowish-brown, dense and irregular spherical shape, average size was 1.49 mm, water content and specific density were 98.13% and 1.0114, the SVI and settling velocity were 40 ml/g and 46.5m/h. After 38 days, NO3(-)-N accumulated obviously in the reactor as lack of carbon sources. When adding 1-3g solid CH3COONa at 4.5 and 5.5h of each cycle from the 57th day, the removal rate of TN rose to above 90% after 20 days, where effective COD removal and denitrification were realized in a single bioreactor. Finally, the removal rates of COD, TP, TN and NH4(+)-N were higher than 95%, 88%, 96% and 99%. PMID:25058300

Long, Bei; Yang, Chang-zhu; Pu, Wen-hong; Yang, Jia-kuan; Shi, Ya-fei; Wang, Jing; Bai, Jun; Zhou, Xuan-yue; Jiang, Guo-sheng; Li, Chun-yang; Liu, Fu-biao

2014-10-01

312

Nitrogen dynamics model for a pilot field-scale novel dewatered alum sludge cake-based constructed wetland system.  

PubMed

A model simulating the effluent nitrogen (N) concentration of treated animal farm wastewater in a pilot on-site constructed wetland (CW) system, using dewatered alum sludge cake (DASC) as wetland substrate, is presented. The N-model was developed based on the Structural Thinking Experiential Learning Laboratory with Animation software and is considering organic nitrogen, ammonia nitrogen (NH3) and nitrate nitrogen (NO3-N) as the major forms of nitrogen involved in the transformation chains. Ammonification (AMM), ammonia volatilization, nitrification (NIT), denitrification, plant uptake, plant decaying and uptake of inorganic nitrogen by algae and bacteria were considered in this model. pH, dissolved oxygen, temperature, precipitation, solar radiation and nitrogen concentrations were considered as forcing functions in the model. The model was calibrated by observed data with a reasonable agreement prior to its applications. The simulated effluent detritus nitrogen, NH4-N, NO3-N and TN had a considerably good agreement with the observed results. The mass balance analysis shows that NIT accounts for 65.60%, adsorption (ad) (11.90%), AMM (8.90%) followed by NH4-N (Plants) (5.90%) and NO3-N (Plants) (4.40%). The TN removal was found 52% of the total influent TN in the CW. This study suggested an improved overall performance of a DASC-based CW and efficient N removal from wastewater. PMID:25179044

Kumar, J L G; Zhao, Y Q; Hu, Y S; Babatunde, A O; Zhao, X H

2015-03-01

313

Start-up of a full-scale deammonification SBR-treating effluent from digested sludge dewatering.  

PubMed

This study shows the start-up and operation of a full-scale sequencing batch reactor (SBR) with a volume of 550 m³ for deammonification of reject water from sludge dewatering over the first 650 days of operation. The SBR was operated with discontinuous aeration and achieved an optimum of around 85% of ammonium removal at a load of 0.17 kg m(-3) d(-1). The application of batch tests for the activity measurement of aerobic ammonium and nitrite oxidizing bacteria and anaerobic ammonium oxidizing bacteria were proven to support the identification of setbacks in reactor operation. Furthermore, the calculation of the oxygen uptake rates from online oxygen measurements helped to explain the overall reactor performance. The aeration regime is a key parameter for stable operation of such an SBR for deammonification. At aeration/non-aeration time ranges from 6-9 min, the best results with respect to turnover rates and low nitrate production were achieved. Compared with the nitrification/denitrification SBR operated in parallel with methanol as the carbon source, a significant reduction in costs for energy and chemicals was achieved. The costs for maintenance slightly increased. PMID:25746647

Lackner, Susanne; Thoma, Konrad; Gilbert, Eva M; Gander, Wolfgang; Schreff, Dieter; Horn, Harald

2015-01-01

314

Case study of odor and indoor air quality assessment in the dewatering building at the Stickney Water Reclamation Plant.  

PubMed

Indoor air quality (IAQ) and odors were determined using sampling/monitoring, measurement, and modeling methods in a large dewatering building at a very large water reclamation plant. The ultimate goal was to determine control strategies to reduce the sensory impacts on the workforce and achieve odor reduction within the building. Study approaches included: (1) investigation of air mixing by using CO(2) as an indicator, (2) measurement of airflow capacity of ventilation fans, (3) measurement of odors and odorants, (4) development of statistical and IAQ models, and (5) recommendation of control strategies. The results showed that air quality in the building complies with occupational safety and health guidelines; however, nuisance odors that can increase stress and productivity loss still persist. Excess roof fan capacity induced odor dispersion to the upper levels. Lack of a local air exhaust system of sufficient capacity and optimum design was found to be the contributor to occasional less than adequate indoor air quality and odors. Overall, air ventilation rate in the building has less effect on persistence of odors in the building. Odor/odorant emission rates from centrifuge drops were approximately 100 times higher than those from the open conveyors. Based on measurements and modeling, the key control strategies recommended include increasing local air exhaust system capacity and relocation of exhaust hoods closer to the centrifuge drops. PMID:22277239

Sharma, Manju; O'Connell, Susan; Garelli, Brett; Sattayatewa, Chakkrid; Moschandreas, Demetrios; Pagilla, Krishna

2012-01-01

315

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

316

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

317

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

PubMed

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

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

2013-11-15

318

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

319

Recovery and reconnaissance of the Leading Creek watershed, Meigs County, Ohio, following a dewatering of Meigs {number_sign}31 coal mine  

SciTech Connect

A database has been developed before and after the dewatering of the Meigs {number_sign}31 deep coal mine in Meigs County, Ohio, three years ago. This strategy was to compare potential recovery of the watershed in the mainstem of Leading Creek as well as to reconnaissance the tributaries for point-source input into the creek. After the dewatering process, {approximately} half of the 31-mile Leading Creek mainstem received a discharge of conductivity, low pH, high metals (iron, manganese, copper, aluminum), and total suspended solids (TSS). Most forms of aquatic life in the creek were depleted in the impacted areas, but recovery has been encouraging. Relative fish abundance has returned to pre-event levels, while benthic macroinvertebrates show recovery in two key stream segments. Reconnaissance of the watershed indicated that the system is uniquely segregated with high sedimentation from agricultural input in the upper half and abandoned mined land (AML) discharges in the lower. The AML-influenced tributaries were intermittently toxic throughout the year with 48-hr LC50 values of 14.6--6.0% effluent at Thomas Fork tributary. Macroinvertebrate assemblages in many of the AML and agriculturally influenced tributaries ranged from 0--3 taxa. The consequence of erosion/sedimentation loading is being addressed relative to autochromous input of in-stream AML/TSS input versus that from allochthomous input from stream bank/land use management.

Currie, R.J.; Astin, L.E.; Yeager, M.M.; Cherry, D.S.; Hassel, J.H. van [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Biology; [American Electric Power Service Corp., Columbus, OH (United States)

1995-12-31

320

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

321

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

322

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

323

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

324

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

325

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids.  

PubMed

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with (14)C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. PMID:25644844

Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Lapen, David R; Topp, Edward

2015-04-15

326

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

327

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

SciTech Connect

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

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

1995-12-31

328

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

PubMed

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

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

2014-10-15

329

Sreambank Dewatering for Increased Stability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Streambank erosion is often the dominant source of sediment leaving watersheds disturbed by human activities. Collapse of high, steep banks is one of the most serious forms of streambank erosion. The risk of a given bank experiencing mass failure is a function of bank height, angle, and soil streng...

330

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

SciTech Connect

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

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

1993-04-01

331

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

332

ACOUSTIC FORMING FOR ENHANCED DEWATERING AND FORMATION  

SciTech Connect

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

Cyrus K Aidun

2007-11-30

333

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

334

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

335

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 ...

336

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

337

Chemical and physical pretreatment of ATAD biosolids for dewatering  

Microsoft Academic Search

This paper reports on two modifications to the typical practice of polymer conditioning intended to enhance the dewaterability of autothermal thermophilic aerobic digested (ATAD) biosolids. One modification was a chemical pretreatment, using ferric chloride prior to polymer conditioning, and the other was a physical pretreatment using an electrical arc technology before polymer addition. These modifications were evaluated separately and in

M. M. Abu-Orf; P. Griffin; S. K. Dentel

2001-01-01

338

Chemical and physical pretreatment of ATAD biosolids for dewatering.  

PubMed

This paper reports on two modifications to the typical practice of polymer conditioning intended to enhance the dewaterability of autothermal thermophilic aerobic digested (ATAD) biosolids. One modification was a chemical pretreatment, using ferric chloride prior to polymer conditioning, and the other was a physical pretreatment using an electrical arc technology before polymer addition. These modifications were evaluated separately and in combination, in laboratory conditioning experiments using ATAD biosolids. Results showed that neither ferric chloride nor the arc treatment is sufficient to produce dewaterable biosolids without the use of polymer. However, use of a ferric chloride dose as low as 100 g per kg of dry solids reduced the polymer requirement by about 50%. The arc treatment provided further enhancement of dewaterability, but the observed benefits might not justify its use without further optimization. For this purpose, additional methods were utilized to assist in understanding the pretreatment mechanisms. PMID:11794671

Abu-Orf, M M; Griffin, P; Dentel, S K

2001-01-01

339

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

340

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

341

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...

342

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...

343

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

344

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

345

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

346

COMPOSTING: STABILIZATION, DEWATERING, VOLUME REDUCTION, AND PATHOGEN KILL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aerobic composting is the biological oxidative decomposition of organic materials by successive communities of microorganisms under different temperature regimes which produces a humified end-product. Composting reduces moisture content of organic byproducts. Thermophilic temperatures attained dur...

347

DRYING AND DEWATERING R&D IN JAPAN  

Microsoft Academic Search

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

Masanobu Hasatani; Noriyuki Kobayashi; Zhanyong Li

2001-01-01

348

Outline of an inclined head wall of a dewatering outlet  

Microsoft Academic Search

Conclusions 1.The proposed outlines of head walls with inclined pressure faces have greater compactness than elliptical head walls. The investigated head walls in model tests had flow separation at values of Cp max considerably greater than the elliptical. The head walls described in [1] are in a mathematical respect limit cases of those examined here, when point C indefinitely approaches

Ya. R. Berman

1982-01-01

349

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...

350

Method of waste stabilization with dewatered chemically bonded phosphate ceramics  

DOEpatents

A method of stabilizing a waste in a chemically bonded phosphate ceramic (CBPC). The method consists of preparing a slurry including the waste, water, an oxide binder, and a phosphate binder. The slurry is then allowed to cure to a solid, hydrated CBPC matrix. Next, bound water within the solid, hydrated CBPC matrix is removed. Typically, the bound water is removed by applying heat to the cured CBPC matrix. Preferably, the quantity of heat applied to the cured CBPC matrix is sufficient to drive off water bound within the hydrated CBPC matrix, but not to volatalize other non-water components of the matrix, such as metals and radioactive components. Typically, a temperature range of between 100.degree. C.-200.degree. C. will be sufficient. In another embodiment of the invention wherein the waste and water have been mixed prior to the preparation of the slurry, a select amount of water may be evaporated from the waste and water mixture prior to preparation of the slurry. Another aspect of the invention is a direct anyhydrous CBPC fabrication method wherein water is removed from the slurry by heating and mixing the slurry while allowing the slurry to cure. Additional aspects of the invention are ceramic matrix waste forms prepared by the methods disclosed above.

Wagh, Arun; Maloney, Martin D.

2010-06-29

351

Photoinitiated polymerization of cationic acrylamide in aqueous solution: synthesis, characterization, and sludge dewatering performance.  

PubMed

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. PMID:24683343

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

2014-01-01

352

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

Code of Federal Regulations, 2010 CFR

...255 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for Documented Vessels That Operate Beyond the Boundary Lines or With More Than 16...

2010-10-01

353

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

354

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

Microsoft Academic Search

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

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

2005-01-01

355

REDUCING RIVERBANK RETREAT RATES BY DE-WATERING USING LOW COST SUBMERSIBLE PUMPS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bank retreat due to mass failure causes the loss of thousands of hectares of land every year in the US and elsewhere, and is a major source of sediment and contaminants in rivers and streams. A self-contained and low-cost submersible pump system has been tested in a section of incised streambank in...

356

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

357

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

Microsoft Academic Search

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

Keith B. Lewis; Bruce A. Marshall

1996-01-01

358

Evaluation of Ferrate(VI) as an Conditioner for Dewatering Wastewater Biosolids  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land application of sludge/biosolids is a commonly used practice for final utilization. Therefore, adequate conditioning and stabilization of wastewater solids is very critical for safe land application. The addition of ferrate (FeO42-) has the potential to improve the dewaterbility of solids, des...

359

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

Microsoft Academic Search

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

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

1985-01-01

360

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

361

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

362

Extending shelf-life of ready-to-eat microgreens by optimizing dewatering procedure  

Technology Transfer Automated Retrieval System (TEKTRAN)

Microgreens have gained increasing popularity as food ingredients in recent years, because of their high nutritional value, as well as their abundant, diverse, and distinct sensorial characteristics including a variety of fresh flavors and aromas and vivid colors. However, their commercial productio...

363

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

364

Minimizing the energy requirement of dewatering scenedesmus sp. by microfiltration: performance, costs, and feasibility.  

PubMed

The harvesting of the microalgae Scenedesmus species using a 200 L pilot-scale microfiltration system was investigated and critically assessed. The energy requirement was determined and correlated to the different operating parameters, such as transmembrane pressure (?P), membrane area, temperature, and initial biomass concentration. A filtration model was developed and showed a strong correlation with experimental data up to 20.0 g of dry cell weight (DCW)/L. The non-optimized filtration system had an energy requirement of 2.23 kWh/m(3) with an associated cost of $0.282/kg of microalgae. The investigation into the influence of the operating parameters and scale-up effects showed that the energy requirement could be substantially reduced to 0.90 kWh/m(3) and $0.058/kg of microalgae harvested. Maintenance costs associated with cleaning were estimated to be 0.23 kWh or $0.029/batch of microalgae processed. Dependent upon the operating conditions, harvesting may represent 6-45% of the energy embedded in the microalgae with a carbon footprint of 0.74-1.67 kg of CO2/kg of microalgae. Microfiltration was demonstrated to be a feasible microalgae harvesting technology allowing for more than 99% volume reduction. The energy requirement and associated carbon footprint of microalgae harvesting reported here do not forfeit the need for an industrial-scale study; however, the information provided presents a more realistic approximation than the literature reported to date. PMID:24341825

Gerardo, Michael L; Oatley-Radcliffe, Darren L; Lovitt, Robert W

2014-01-01

365

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

366

Theories of cake filtration and consolidation and implications to sludge dewatering  

Microsoft Academic Search

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

D. J. Lee; C. H. Wang

2000-01-01

367

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

Microsoft Academic Search

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

Brian R. Pratt

1998-01-01

368

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

369

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

SciTech Connect

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

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

1999-07-01

370

Water1977 (dewatering of sludges from oil fired electric power generating plants)  

Microsoft Academic Search

Pollutants removed from wastewaters from power generating plants produce sludges that are usually deposited in landfill sites. Since the cost of hauling and disposal increases as the amount of sludge increases, sludge generation volume is an important consideration in evaluating the economic feasibility of a treatment system. Sludge volume is a function of the chemical composition of wastewater streams, the

M. M. Zuckerman; R. V. Peltier

1978-01-01

371

The effect of relatively small scale structural features on fluid flow, fluid entrapment, and tectonic dewatering  

NASA Astrophysics Data System (ADS)

Frequently, analysis of a system concentrates on large features. These are relatively easy to identify and it is easy to believe that the most prominent feature has the greatest impact on a system. During structural analysis of geologic systems, large deformation features are generally more thoroughly studied. However, small scale features occur in greater numbers and are penetrative, therefore providing insight into the behavior of systems that a few large scale features cannot. Penetrative small scale structures also affect large volumes of rock and may significantly alter the rock's physical properties and mechanical behavior. Small scale deformation features and their effect on hydrologic systems is approached in three ways in this thesis. Optical and electron microscopy analyses of cores from the Cascadia accretionary prism reveal pervasive ductile deformation throughout the wedge on a centimeter scale. Faults with thickness on the scale of a millimeter show evidence of failure under low strength conditions and localized fluid and granular flow. This work provides direct support for hypotheses of weak faults and high fluid pressure within prisms. Well log analysis in the Long Beach Unit of the Wilmington oil field illustrates the distribution of strain and juxtaposition of oil reservoirs across a fault with maximum displacement of ˜30 m. Though previously considered too small to impact the hydrologic system, the fault is found to be capable of trapping a 290 m column of oil. Smaller faults identified in this study likely control a flow anisotropy noted during production. Correlation of log and 3D seismic data within the Barbados accretionary prism reveals small faults with tens of meters of displacement and hundreds to thousands of meters of lateral extent. The complex internal prism structure results in discrete changes in the compaction state of accreted sediments. Sediments undergo the majority of deformation within the first few kilometers of the prism, only deep sections continuing to deform within the wedge. Immediately seaward of the prism, small scale deformation features indicate a 90sp° shift in the orientation of maximum principal stress. Though these studies are vastly different in scope and methodology, in each case my concern has been to assess the impact of the smaller scale structural details of a system. I hope that anyone who reads this work comes away with an appreciation for features that are just below our resolution.

Teas, Philip Allen

372

Pressate from peat dewatering as a substrate for bacterial growth. [Rhizopus arrhizus; Xanthomonas campestris; Aureobasidium  

SciTech Connect

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

Mulligan, C.N.; Cooper, D.G.

1985-07-01

373

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

374

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. PMID:24683343

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

2014-01-01

375

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

Microsoft Academic Search

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

Antonis A Zorpas; Dimitris Arapoglou; Karlis Panagiotis

2003-01-01

376

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

EPA Science Inventory

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

377

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

Microsoft Academic Search

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

Patience Mpofu; Jonas Addai-Mensah; John Ralston

2003-01-01

378

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

Microsoft Academic Search

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

Luigi Naselli-Flores; Rossella Barone

2005-01-01

379

Working to gain public acceptance of sewage sludge composting and use of liquid and dewatered sludge on land  

SciTech Connect

The purpose of this paper is (1) to examine those factors that especially spark the resistance and concern of citizens to land utilization and composting of sewage sludge and (2) to characterize essential ingredients that are invariably a part of the most successful systems for reducing the resistance and minimizing the concerns of these citizens. Experiences in the Washington, D.C. Metropolitan Area will be discussed which show how municipal authorities and/or their agents have worked with citizens. These discussions show how their efforts have either alleviated or increased citizen concern and resistance to sludge utilization and composting.

Walker, J.M.

1995-06-01

380

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

USGS Publications Warehouse

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

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

2012-01-01

381

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

SciTech Connect

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

Smith, L.B.; Durney, T.

1991-01-01

382

Theoretical development and validation of a Sharp Front model of the dewatering of a slurry by an absorbent substrate  

NASA Astrophysics Data System (ADS)

The absorption of water from a slurry into an absorbent substrate is analysed using Sharp Front theory. The analysis describes the relationship between the sorptivity S of the substrate, the desorptivity R of the slurry and the transfer sorptivity A between slurry and substrate, and leads to the relationship 1/A2 = 1/R2 + 1/S2. Experimental data are presented which validate this equation for the practically important case of the absorption of water from soft mortar mixes by fired clay bricks. A unique feature of the experimental work is the measurement of the desorptivity of the mortars at a pressure equal to the wetting front capillary pressure of the clay brick substrate. Analysis of the experimental data also enables, for the first time, the calculation of the capillary potential at the slurry/substrate interface. The analysis has relevance to many aspects of ceramic and mineral processing, industrial filtration and construction engineering.

Collier, N. C.; Wilson, M. A.; Carter, M. A.; Hoff, W. D.; Hall, Christopher; Ball, R. J.; El-Turki, A.; Allen, G. C.

2007-07-01

383

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

384

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

Microsoft Academic Search

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

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

2004-01-01

385

Analytical solution for enhanced recharge around a bedrock exposure caused by deep-aquifer dewatering through a variable thickness aquitard  

NASA Astrophysics Data System (ADS)

In this study an analytical solution was developed to predict steady radially-symmetric percolation rates from an aquifer underlain by a variable thickness aquitard. The solutions consider an aquitard with constant thickness and with radial-symmetrically increasing thickness outward from the center. The solution was used to predict the percolation rate from a peat layer around a bedrock outcrop in the James Bay Lowland near the De Beers Victor diamond mine. In this case the marine sediment layer limited the direct connection between the peat layer and the bedrock as an aquitard. Our zero order solution with constant marine sediment thickness showed the best fit to the steady state water level data of June 2012. It was found that the enhanced recharge around bioherms (i.e., at rates greater than the regional average of 0.7 mm/day) will only occur in marine sediments less than 4.3 m thick, for extreme depressurization of 30 m.

Kompanizare, Mazda; Price, Jonathan S.

2014-12-01

386

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

USGS Publications Warehouse

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

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

1989-01-01

387

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

Microsoft Academic Search

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

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

2005-01-01

388

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

389

76 FR 77561 - Atomic Safety and Licensing Board; In the Matter of Progress Energy Florida, Inc.; (Levy County...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and other waters, associated with dewatering, specifically: 1. Impacts resulting from active and passive dewatering; 2. Impacts resulting from the...destructive wildfires resulting from dewatering. B. Impacts to wetlands,...

2011-12-13

390

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

391

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

392

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

393

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-02-09

394

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

395

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

396

77 FR 51832 - Atomic Safety and Licensing Board; In the Matter of Progress Energy Florida, Inc. (Levy County...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and other waters, associated with dewatering, specifically: 1. Impacts resulting from active and passive dewatering; 2. Impacts resulting from the...destructive wildfires resulting from dewatering. B. Impacts to wetlands,...

2012-08-27

397

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

398

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

Code of Federal Regulations, 2014 CFR

...a specific area of the site necessitates that it remain disturbed. (c) Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, are prohibited unless managed by...

2014-07-01

399

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

400

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

401

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

402

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

403

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

404

FRUIT CANNERY WASTE ACTIVATED SLUDGE AS A CATTLE FEED INGREDIENT  

EPA Science Inventory

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

405

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

406

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

407

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

408

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-02-03

409

40 CFR 141.76 - Recycle provisions.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

410

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

E-print Network

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

Paris-Sud XI, Université de

411

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

E-print Network

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

Goldfinger, Chris

412

2005 Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or editing@geosociety.org. Geology; August 2005; v. 33; no. 8; p. 625628; doi: 10.1130/G21270.1; 4 figures; 1 table. 625  

E-print Network

; 1 table. 625 Formation of Martian outflow channels by catastrophic dewatering of evaporite deposits channels through catastrophic dewatering of evaporite deposits. MOLA transects across Valles Marineris show

Montgomery, David R.

413

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

E-print Network

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

Mountziaris, T. J.

414

College of Engineering Summer Research Experience for Undergraduates Program  

E-print Network

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

Mountziaris, T. J.

415

BidOpportunity Bid Opportunity  

E-print Network

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

Qian, Ning

416

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

E-print Network

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

417

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

E-print Network

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

Kamat, Vineet R.

418

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

E-print Network

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

Paris-Sud XI, Université de

419

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

E-print Network

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

Aydilek, Ahmet

420

SUPERVIVENCIA DE BACTERIAS FECALES EN LODOS RESIDUALES DESHIDRATADOS TRATADOS CON AMONIACO FECAL BACTERIA SURVIVAL IN AMMONIA-TREATED WASTEWATER DEWATERED SLUDGES  

Microsoft Academic Search

One of most important pollution problems in sludge from municipal and agro industrial wastewater treatment plants of Mexico is the high level of pathogens microorganisms. Ammonia is known as an important disinfectant capable to significantly inactivate high microbial populations in sludge. In this study, the effect of ammonia was evaluated in agro industrial physicochemical sludge and kinetic parameters of the

J. M. Méndez; C. González; A. Alvarado-Lassman

2008-01-01

421

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

SciTech Connect

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

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

1992-12-31

422

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

DOEpatents

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

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

1994-01-01

423

Reduction in energy usage during dry grind ethanol production by enhanced enzymatic dewatering of whole stillage: plant trial, process model and economic analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

A plant trial was conducted at a 54 MGPY dry grind fuel ethanol facility to evaluate the use of enhanced water removal from whole stillage by enzyme addition during fermentation. Laboratory data had previously shown significant improvements in water removal that could potentially result in significa...

424

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

Microsoft Academic Search

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

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

2003-01-01

425

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

USGS Publications Warehouse

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

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

1991-01-01

426

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

SciTech Connect

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

Smith, L.B.; Durney, T.

1991-12-31

427

A new model of coal-water interaction and relevance for dewatering. Quarterly technical progress report, 1 March--31 May 1993  

SciTech Connect

It has been noted that there is no single, distinct measure of the bulk modulus of coals measurable in mercury porosimetry experiments. As with other modulus measurements on coal, there is a hysteresis associated with these measurements of bulk modulus. The hysteresis is presumably associated with the time-dependent reorganization of its macromolecular network structure, in response to the applied stresses. The above results confirm what has been inferred from other types of measurements on the porosity and surface areas of coals. It has been concluded that because coal behaves as a viscoelastic gel ( as opposed to a rigid solid) on the timescales of interest, then many of the ``classical`` characterizations of porosity might provide a misleading picture of the structure of coals. Here, it has been specifically concluded that ``corrections`` for coal compressibility, commonly used in mercury porosimetry work on raw coals, are subject to some uncertainty from this source. At the higher temperatures of actual coal processing, and especially in the presence of solvents, there is an even greater uncertainty concerning the applicability of these measurements, since the physical structure of the coal can be dramatically altered. The apparent bulk moduli of coals do not vary widely with rank. The pre-extraction of the coal or presence of water in the coal affect the moduli by only a small amount. Water is an effective swelling agent for low rank coals, swelling lignites by 30 to 40%, relative to a dry state. There is, however, no evidence from the values of bulk modulus obtained here that the rubbery state of the coal, as is attainable in pyridine swelling of higher ranks, exists in the wet lignites. We therefore indirectly support earlier workers in their conclusion that the effect of moisture content on dynamic moduli is small.

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

1993-12-31

428

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

DOEpatents

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

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

1994-11-22

429

Modeling Hydrodynamics and Bed-Load Transport of Coarse Sediments in the Great Bay Estuary, NH, Using a 2-D Kinematic Flooding-Dewatering Model  

E-print Network

complex system with low freshwater input, having main channel tidal currents ranging between 0.5 and 2 m boundary computational domain and accounts for flooding-drying of tidal flats by making use of a groundwater component. Inertia terms are neglected in comparison with pressure gradient and bottom friction

430

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

E-print Network

of these outbreaks (85.7%) were caused by E. coli O157:H7 (1). Produce grows in natural environment but could leach out from cut surfaces and contaminate the production batch. In the fresh-cut processing disinfectants in wash water to minimize potential cross contamination (1, 3). However, little is known about

Heller, Barbara

431

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

E-print Network

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

Paris-Sud XI, Université de

432

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

E-print Network

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

Paris-Sud XI, Université de

433

Geotechnical and environmental impacts on the surface of the water rising in French Underground coal mines after closure.  

E-print Network

in Underground coal mines, after their closure and, therefore, to the interruption of the dewatering pumping, may of an Underground mine generally gives rise to the interruption of the dewatering pumping. The resulting rise

Paris-Sud XI, Université de

434

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

E-print Network

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

Sandiford, Mike

435

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

E-print Network

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

Paris-Sud XI, Université de

436

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

E-print Network

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

Merguerian, Charles

437

Chemical Engineering Journal 111 (2005) 91103 Numerical identification of parameters for a flocculated suspension  

E-print Network

identification; Centrifugation; Numerical technique 1. Introduction Solid­liquid separation or dewatering developed in [1­3]. This theory is equivalent to the theory of suspension dewatering utilized in [4­7] (see

Sepúlveda, Mauricio

438

78 FR 15374 - Notice of Availability of Draft Habitat Conservation Plan; Receipt of Application for Incidental...  

Federal Register 2010, 2011, 2012, 2013, 2014

...including excavation, pipeline inspection and repair, dewatering, temporary work area and spoil pile stock, backfilling excavation...project. Temporary impacts will result from winter excavation, dewatering, and backfilling, which may destroy overwintering...

2013-03-11

439

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

440

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

441

MINE DEVELOPMENT SURFACE WATER  

E-print Network

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

Boisvert, Jeff

442

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

443

40 CFR 421.156 - Pretreatment standards for new sources.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

444

ECONOMIC GEOLOGY BULLETIN OF THE SOCIETY OF ECONOMIC GEOLO.GISTS  

E-print Network

to the surface before reaching the district. Episodic dewatering events are unlikely to have occurred, because dewatering variant, sediment com- paction in basins causes high excess pore pressures, such as those observed

Bethke, Craig

445

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

446

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

447

40 CFR 421.156 - Pretreatment standards for new sources.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

448

ASSOCIATION OF WASTE STABILISATION PONDS AND INTERMITTENT SAND FILTERS  

E-print Network

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

Paris-Sud XI, Université de

449

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

450

CREATE A SAFE CONSTRUCTION  

E-print Network

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

Shihadeh, Alan

451

40 CFR 421.156 - Pretreatment standards for new sources.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

452

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

453

76 FR 45792 - Proposed Reissuance of a General NPDES Permit for Facilities Related to Oil and Gas Extraction  

Federal Register 2010, 2011, 2012, 2013, 2014

...previous general permit except for domestic wastewater discharges. The covered discharges include gravel pit dewatering, construction dewatering, hydrostatic test water, mobile spill response, and storm water from industrial activities. The...

2011-08-01

454

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2013-01-18

455

Chi-man Leung Jiu J. Jiao  

E-print Network

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

Jiao, Jiu Jimmy

456

40 CFR 98.468 - Definitions.  

Code of Federal Regulations, 2014 CFR

...includes the semi-solid materials remaining after these materials are dewatered via a belt process, centrifuge, or similar dewatering process. Solid waste has the meaning established by the Administrator pursuant to the Solid Waste Disposal Act (42...

2014-07-01

457

40 CFR 421.156 - Pretreatment standards for new sources.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

458

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

459

Dr. H.M. Watt Project QA Officer  

E-print Network

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

District of Columbia, University of the

460

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

461

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

462

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

E-print Network

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

Jager, Henriette I.

463

Regional P wave velocity structure of the Northern Cascadia Subduction Zone  

E-print Network

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

Ramachandran, Kumar

464

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

E-print Network

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

465

40 CFR 421.156 - Pretreatment standards for new sources.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

466

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

E-print Network

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

Benton, Michael

467

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2013-02-04

468

Capillary Suction Time (CST) Test: Developments in testing methodology and reliability of results   

E-print Network

The dewatering of wastewater sludge (slurry) is a routine operation at wastewater treatment plants, and the results of dewaterability tests underpin the selection of dewatering processes. The two most commonly applied ...

Sawalha, Ola

2011-01-01

469

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

E-print Network

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

470

Fruit cannery waste activated sludge as a cattle feed ingredient  

Microsoft Academic Search

The feasibility of sludge disposal from a fruit processing waste activated sludge treatment system by dewatering and using the dewatered biological sludge solids as cattle feed was evaluated by Snokist Growers at Yakima, Washington. Dewatering of the biological sludge utilizing pilot-scale and prototype-scale basket centrifuges resulted in consistently dewatering to 7-1\\/2% to 9% dry solids. Digestibility and metabolizability of rations

Esvelt

1976-01-01

471

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

E-print Network

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

Li, Perry Y.

472

APPENDIX A. EQUIPMENT MODIFICATION DESIGN STUDY SUMMARY  

E-print Network

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

Brookhaven National Laboratory

473

Managed for the U.S. Department of Energy by Brookhaven Science Associates  

E-print Network

­ Hydro Dam 2004 Mat Road #12;12 2010 Dewatering Summary Sump-pumps between hydro dams to be used to dewater excavation area Similar to 2004/2005 2005 - Filter Bag Sump-pump discharge water to be filtered before return to Peconic Similar to 2004/2005 Sump to Pump Pump to Filter 2005 ­ Dewatering Pump #12

Homes, Christopher C.

474

ADAPTIVE CALIBRATION AND CONTROL OF CASCADE PROCESSES WITH UNKNOWN MEASUREMENT MODEL AND ACTUATOR DYNAMICS AND ITS  

E-print Network

is applied to a vacuum dewatering process in paper manufacturing industry. Simulation results show. The vacuum dewatering section in paper manufacturing pro- cess is the motivating example for this class of systems, where moist paper is successively dewatered by multiple vacuum de- watering boxes whose pressure

Li, Perry Y.

475

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

E-print Network

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

Boyer, Edmond

476

1 INTRODUCTION Considerable evidence has been provided by the recent studies  

E-print Network

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

Aydilek, Ahmet

477

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

E-print Network

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

Paris-Sud XI, Université de

478

JOIDESJournal Joint Oceanographic Institutions for Deep Earth Sampling  

E-print Network

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

479

TEXT UPDATED: 2/16/2012 FIRST OPEN SOLICITATION  

E-print Network

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

Rollins, Andrew M.

480

Page 1 of 5 Installation Name ____________________________________________________________  

E-print Network

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

US Army Corps of Engineers

481

Water quality Water quantity  

E-print Network

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

Boisvert, Jeff

482

subsidence from ratesofverticalmotion(cmyr-1  

E-print Network

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

Kulp, Mark

483

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

E-print Network

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

Doyle, Martin

484

eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic  

E-print Network

Title: Emplacement and dewatering of the world's largest exposed sand injectite complex Author: Sherry 1 17 August 2012 Q08008, doi:10.1029/2012GC004157 ISSN: 1525-2027 Emplacement and dewatering, multiple pore fluids, and dewatering after emplacement. The injection was initially mobilized from a source

485

Project EARTH-12-SHELL4: Shell Geoscience Laboratory  

E-print Network

Project EARTH-12-SHELL4: Shell Geoscience Laboratory Polygonal faults and de-watering of mudrocks (subject to contract) Polygonal faults are widely regarded as a response to dewatering during the earliest it is generally agreed that polygonal fault genesis is related to dewatering during the first few hundred metres

Henderson, Gideon

486

India: Gujarat  

Atmospheric Science Data Center

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

2013-04-16

487

Peter Leete DNR Transportation Hydrologist, and MnDOT Liaison  

E-print Network

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

Minnesota, University of

488

Department of Civil & Environmental Engineering Geotechnical Group Seminar Series  

E-print Network

of Michigan, Ann Arbor Dewatering Wells in a Flowing Artesian Aquifer at Ann Arbor WWTP By Katherine M. Lamb on this seminar series: http://www.umich.edu/~geotech/lecture.html Dewatering, Bypass Pumping, & Power Generation Abstract: Large diameter drilled wells are used all over the world for temporary dewatering activities

Kamat, Vineet R.

489

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

E-print Network

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

Li, Perry Y.

490

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

E-print Network

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

Aydilek, Ahmet

491

Novel Nanoscale Materials Reduce Electricity Needed for Sludge  

E-print Network

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

492

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

E-print Network

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

Li, Perry Y.

493

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

E-print Network

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

Farritor, Shane

494

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

E-print Network

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

Li, Perry Y.

495

Centrifuges Replacement Study Proposal  

E-print Network

the dense product from slurry by dewatering or washing cycles. Specifications: Manufacturer: Ametek (process equipment division) Type: Tolhurst 48? X 30? Quick-Dismantle Basket Type Centrifuge Basket Diameter 48" Basket RPM 1080 Basket Depth 30...-liquid mixture to be separated is processed by the Distribution, Intermediate dewatering, Washing, Final dewatering, and Solid discharge operations. These operations are processed in the centrifuge successively and at the same place. 7 Figure below shows...

Iqbal, Muhammad

2005-12-16

496

The Optimization of Well Spacing in a Coalbed Methane Reservoir  

E-print Network

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

Sinurat, Pahala Dominicus

2012-02-14

497

Modelling the evolution of water quality in abandoned mines of the Lorraine Iron Basin  

Microsoft Academic Search

Mining operations disrupt the local groundwater balance both during and after mining. The galleries excavated during mining of