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Development of an analytical model for organic-fluid fouling

Description: The research goal of this project is to determine ways to effectively mitigate fouling in organic fluids: hydrocarbons and derived fluids. The fouling research focuses on the development of methodology for determining threshold conditions for fouling. Initially, fluid containing chemicals known to produce foulant is analyzed; subsequently, fouling of industrial fluids is investigated. The fouling model developed for determining the effects of physical parameters is the subject of this report. The fouling model is developed on the premise that the chemical reaction for generation of precursor can take place in the bulk fluid, in the thermal-boundary layer, or at the fluid/wall interface, depending upon the interactive effects of fluid dynamics, heat and mass transfer, and the controlling chemical reaction. In the analysis, the experimental data are examined for fouling deposition of polyperoxide produced by autoxidation of indene in kerosene. The effects of fluid and wall temperatures for two flow geometries are analyzed. The results show that the relative effects of physical parameters on the fouling rate differ for the three fouling mechanisms. Therefore, to apply the closed-flow-loop data to industrial conditions, the controlling mechanism must be identified.
Date: October 1, 1994
Creator: Panchal, C.B. & Watkinson, A.P.
Partner: UNT Libraries Government Documents Department

Algae control problems and practices workshop

Description: Western water resources are continuously facing increased demand from industry and the public. Consequently, many of these resources are required to perform multiple tasks as they cycle through the ecosystem. Many plants and animals depend upon these resources for growth. Algae are one group of plants associated with nutrient and energy cycles in many aquatic ecosystems. Although most freshwater algae are microscopic in size, they are capable of dominating and proliferating to the extent that the value of the water resource for both industrial and domestic needs is compromised. There is a great diversity of aquatic environments and systems in which algae may be found, and there are many varieties of treatment and control techniques available to reduce the impacts of excessive growth. This workshop was organized to exchange information about these control problems and practices.
Date: September 1, 1996
Creator: Pryfogle, P.A. & Ghio, G.
Partner: UNT Libraries Government Documents Department

Evaluation of Foaming and Antifoam Effectiveness During the WTP Oxidative Leaching Process

Description: The River Protection Project-Waste Treatment Plant (RPP-WTP) requested Savannah River National Laboratory (SRNL) to conduct small-scale foaming and antifoam testing using a Hanford waste simulant subjected to air sparging during oxidative leaching. The foaminess of Hanford tank waste solutions was previously demonstrated by SRNL during WTP evaporator foaming studies and in small scale air sparger studies. The commercial antifoam, Dow Corning Q2-3183A was recommended to mitigate the foam in the evaporators and in vessel equipped with pulse jet mixers and air spargers. Currently, WTP is planning to use air spargers in the HLW Lag Storage Vessels (HLP-VSL-00027A/B), the Ultrafiltration Vessels (UFP-VSL-00002A&B), and the HLW Feed Blend Vessel (HLPVSL-00028) to assist the performance of the Pulse Jet Mixers (PJM). The previous air sparger antifoam studies conducted by SRNL researchers did not evaluate the hydrogen generation rate expected from antifoam additions or the effectiveness of the antifoam during caustic leaching or oxidative leaching. The fate of the various antifoam components and breakdown products in the WTP process under prototypic process conditions (temperature & radiation) was also not investigated. The effectiveness of the antifoam during caustic leaching, expected hydrogen generation rate associated with antifoam addition, and the fate of various antifoam components are being conducted under separate SRNL research tasks.
Date: October 11, 2005
Creator: Burket, P. R.; Jones, T. M.; White, T. L.; Crawford, C. L. & Calloway, T. B
Partner: UNT Libraries Government Documents Department

PARAMETRIC EFFECTS OF ANTI-FOAM COMPOSITION, SIMULANT PROPERTIES AND NOBLE METALS ON THE GAS HOLDUP AND RELEASE OF A NON-NEWTONIAN WASTE SLURRY SIMULANT

Description: Gas holdup tests were performed in bench-scale and small-scale mechanically-agitated mixing systems at the Savannah River National Laboratory (SRNL) for a simulant of waste from the Hanford Tank 241-AZ-101. These featured additions of DOW Corning Q2-3183A anti-foam agent. Results indicated that this anti-foam agent (AFA) increased gas holdup in the waste simulant by about a factor of four and, counter-intuitively, that the holdup increased as the non-newtonian simulant shear strength decreased (apparent viscosity decreased). Such results raised the potential of increased flammable gas retention in Hanford Waste Treatment and Immobilization Plant (WTP) vessels mixed by air sparging and pulse-jet mixers (PJMs) during a Design Basis Event (DBE). Additional testing was performed to determine the effects of simulant properties, composition of alternate AFAs, and presence of trace noble metals. Key results are that: (1) Increased gas holdup resulting from addition of Q2-3183A is due to a decrease in surface tension that supports small bubbles which have low rise velocities. (2) Dow Corning 1520-US AFA shows it to be a viable replacement to Dow Corning Q2-3183A AFA. This alternative AFA, however, requires significantly higher dosage for the same anti-foam function. (3) Addition of noble metals to the AZ-101 waste simulant does not produce a catalytic gas retention effect with the AFA.
Date: August 7, 2008
Creator: Guerrero, H; Charles Crawford, C & Mark Fowley, M
Partner: UNT Libraries Government Documents Department

Illinois Institute of Technology Report: IITB52 Antifoamer for Alternative Salt Processes

Description: The attached report is a summary of the work performed by Dr. Darsh Wasan, Dr. Alex Nikolov, and their researchers at the Illinois Institute of Technology (IIT) during FY01. IIT developed the IITB52 antifoam for SRTC in FY00 to minimize the foam produced during precipitation, washing and concentration of cesium and potassium tetraphenyl borate precipitate. The IITB52 antifoam has been very successful during continuous processing (prototypical of plant operation). However, there were several key issues where SRTC needed the experience and knowledge of IIT to resolve. As a result a subcontract was set up with Dr. Wasan and Dr. Alex Nikolov during FY01. This subcontract requested IIT to perform the basic research necessary to understand the foaming mechanism and explain the effectiveness of the IITB52 antifoam agent in the Small Tank Tetraphenylborate Process (STTP).
Date: June 27, 2001
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Fate of IIT B52 Antiform Agent Across the Small Tank Tetraphenylborate Process

Description: The primary objective of these experiments was to determine the fate (partitioning) of the antifoam agent across the precipitation, concentration and washing cycles. A secondary objective of this experiment was to determine if insoluble aluminum formed during the STTP process.
Date: July 10, 2001
Creator: Calloway, T.B.
Partner: UNT Libraries Government Documents Department

Waste Treatment Plant LAW Evaporation: Antifoam Performance

Description: This report describes the work performed to determine the performance and fate of several commercial antifoams during evaporation of various simulants of Envelope A, B, and C mixed with simulated River Protection Project Waste Treatment Plant (RPP-WTP) recycle streams. Chemical and radiation stability of selected antifoams was also investigated.Contributors to this effort include: Illinois Institute of Technology (IIT), DOW Corning Analytical, and Savannah River Technology Center (SRTC).
Date: March 29, 2004
Creator: BAICH, MARKA
Partner: UNT Libraries Government Documents Department

Foaming in Hanford River Protection Project Waste Treatment Plant LAW Evaporation Processes - FY01 Summary Report

Description: The LAW evaporation processes currently being designed for the Hanford River Protection Project Waste Treatment Plant are subject to foaming. Experimental simulant studies have been conducted in an effort to achieve an effective antifoam agent suitable to mitigate such foaming.
Date: July 23, 2002
Creator: Calloway, T.B.
Partner: UNT Libraries Government Documents Department

Organotin piezo- and pyroelectric polymer films. [Synthesis, glass transition, and piezo- and pyroelectric activity]

Description: The synthesis of a new class of piezo- and pyroelectrically active materials of various co- and terpolymers of tributylin methacrylate (TBTM) and trimethyltin methacrylate (TMTM) is described. A description of sample preparation, poling techniques, and measurement system is given in some detail. Films of the various polymer compositions were evaluated for tin current, glass transition temperature (Tg), crystallinity or ordering of the amorphous phase and piezo- and pytoelectric activity. Experimental results on 25 to 30 mol% TBTM/methyl methacrylate copolymers, which possessed good piezoelectric activity, antifouling properties and paint-formulation characteristics, are discussed in detail. Solvent-induced orientation effects that lead to piezoelectric activity in amorphous, unpoled, polymers are also described.
Date: January 1, 1983
Creator: Liepins, R.; Timmons, M.L.; Morosoff, N. & Surles, J.
Partner: UNT Libraries Government Documents Department

Foaming and Antifoaming in Radioactive Waste Pretreatment and Immobilization

Description: Radioactive waste treatment processes usually involve concentration of radionuclides before waste can be immobilized by storing it in stable solid form. Foaming is observed at various stages of waste processing like sludge chemical processing and melter operations. Hence, the objective of this research was to study the mechanisms that produce foaming during nuclear waste treatment, to identify key parameters which aggravate foaming, and to identify effective ways to eliminate or mitigate foaming. Experimental and theoretical investigations of the surface phenomenon, suspension rheology, and bubble generation and interactions that lead to the formation of foam during waste processing were pursued under this EMSP project. Advanced experimental techniques including a novel capillary force balance in conjunction with the combined differential and common interferometry were developed to characterize particle-particle interactions at the foam lamella surfaces as well as inside the foam lamella. Laboratory tests were conducted using a non-radioactive simulant slurry containing high levels of noble metals and mercury similar to the High-Level Waste. We concluded that foaminess of the simulant sludge was due to the presence of colloidal particles such as aluminum, iron, and manganese. We have established the two major mechanisms of formation and stabilization of foams containing such colloidal particles: (1) structural and depletion forces; and (2) steric stabilization due to the adsorbed particles at the surfaces of the foam lamella. Based on this mechanistic understanding of foam generation and stability, an improved antifoam agent was developed by us, since commercial antifoam agents were found to be ineffective in the aggressive physical and chemical environment present in the sludge processing. The improved antifoamer was subsequently tested in a pilot plant at the Savannah River Site (SRS) and was found to be effective. Also, in the SRTC experiment, the irradiated antifoamer appeared to be as effective as nonirradiated antifoamers. Therefore, the ...
Date: February 20, 2002
Creator: Wasan, Darsh T.
Partner: UNT Libraries Government Documents Department

Antifouling marine concrete

Description: Various toxic agents were evaluated as to their capability to prevent or inhibit the attachment of marine fouling organisms to concrete for OTEC plants. Creosote and bis-(tri-n-butyltin) oxide (TBTO) were impregnated into porous aggregate which was used in making concrete. Cuprous oxide, triphenyltin hydroxide (TPTH), and 2-2-bis-(p-methoxyphenyl)-1,1,1-trichloroethane (methoxychlor) were used as dry additives. Two proprietary formulations were applied as coatings on untreated concrete. Test specimens were exposed at Port Hueneme, CA, and Key Biscayne, FL. The efficacy of toxicants was determined by periodically weighing the adhering fouling organisms. Concrete prepared with an aggregate impregnated with a TBTO/creosote mixture has demonstrated the best antifouling performance of those specimens exposed for more than one year. The two proprietary coatings and the concrete containing methoxychlor, TPTH, and cuprous oxide as dry additives have exhibited good antifouling properties, but they have been exposed for a shorter time. The strength of concrete containing the toxicants was acceptable, and the toxicants did not increase the corrosion rate of reinforcing rods. Organotin compounds were essentially unchanged in concrete specimens exposed 6-1/2 years in seawater.
Date: July 1, 1980
Creator: Vind, H P & Mathews, C W
Partner: UNT Libraries Government Documents Department

OTEC elastomer cold water pipe preliminary design study. Final report

Description: Goodyear Aerospace Corporation has analyzed the requirements for a 30 ft dia 3280 ft long Cold Water Pipe for an Ocean Thermal Energy Conversion (OTEC) 10/40 MW Pilot Plant. A preliminary design using elastomer covered, flexible steel cable, conveyor belt material is presented. The design concept was predicated on employing state-of-the-art production techniques and having the capability for expansion to a commercial power plant size without further development. The report provides a data base for a compliant elastomer pipe and includes material properties, design details, cost, fabrication and schedule information. Both cable and fabric reinforced constructions are addressed and a comparison of various concepts for assembly of the pipe sections has been made.
Date: November 13, 1979
Creator: Mehring, R D
Partner: UNT Libraries Government Documents Department

Industrial Market Research Report: Feasibility of commercialization of the advanced antifouling coating of Copperlok, Inc

Description: The Copperlok antifouling process was designed to prevent marine growth on surfaces exposed to sea water. It is a method of bonding thermally sprayed Cu and Cu alloys onto an epoxy material containing microballoons (hollow spheres). After the epoxy cures, the surface is abraded so that the microballoons are fractured, exposing microscopic concave porosity. The sprayed material is directed to the surface, where it impregnates the pores, bridges and then welds across the surface, creating a very thin laminate of the metal materials security bonded to the bond coat and to the substrate. The Copperlok process laminates an approximate layer of Cu-Ni alloy 8 mils thick with an expected active life of 15--20 y. This report addresses the perceived acceptability of the process in several different marketplaces with the hope of directing the invention to the most receptive consumer group. The opinion surveys of the recreational marine industry were limited to the three coastal areas of the Atlantic, Gulf, and Pacific.
Date: October 1, 1990
Creator: Gormley, G.J.
Partner: UNT Libraries Government Documents Department

Biological limiting factors in Ocean Thermal Energy Conversion

Description: Ocean thermal energy conversion (OTEC) is one of several solar energy options being considered by the U.S. Energy Research and Development Administration (ERDA). The OTEC concept utilizes the thermal difference between warm surface and cool, deep water in tropical oceans to operate a heat engine to produce either electricity or energy-intensive chemicals. Several OTEC system designs, both open and closed cycle, have been suggested. It is estimated that by the year 2020, 4 to 6% of the anticipated energy needs of the United States could be supplied by OTEC. However, primary biological films that reduce heat transfer at heat exchange surfaces are a major limiting factor to successful development of OTEC technology. Battelle, Pacific Northwest Laboratories (PNL) is managing an ERDA program aimed to define, prevent, and/or alleviate, potential biofouling problems associated with OTEC systems. Extensive research concerning open ocean biofouling and its control will be necessary. The OTEC concept, its history and potential advantages are discussed; various overall system designs are reviewed; and the biological limitations on OTEC development are dicussed. 33 references.
Date: June 1, 1977
Creator: Gray, R. H.
Partner: UNT Libraries Government Documents Department

Comparative evaluation of effects of ozonated and chlorinated thermal discharges on estuarine and freshwater organisms

Description: Although limited, the results of tests evaluating the comparative effects of chlorinated and ozonated thermal discharges on mummichog and white perch indicate that the biological effects of ozonation are much less severe than those of chlorination. The data also show white perch to be more sensitive than mummichog to the tested biocides. The relative effects of ozonation and chlorination in the behavioral studies were similar to those observed in the toxicity studies. Cough rates were higher in chlorinated than in ozonated thermal discharges at similar test concentrations. Avoidance concentrations of white perch were less than those for mummichog and all determined avoidance concentrations were less than lethal levels. The biological effects of any oxidizing biocide on a given species, however, are usually site specific. The chlorine avoidance concentrations of white perch tested at Bergen averaged 0.04 mg/1 total chlorine but averaged 0.06 mg/1 total chlorine when tested in Delaware estuarine waters. Although the amount of data obtained at Bergen is not large, it is indicative of the comparative biological effects in despoiled waters. Assuming such waters will be improved, however, concern then arises over the comparative effects of chlorination and ozonation in waters which support large populations of aquatic organisms. (ERB)
Date: July 23, 1979
Creator: Meldrim, J.W.; Holmstrom, E.R. & Balog, G.E.
Partner: UNT Libraries Government Documents Department

Qualification of aluminum for OTEC heat exchangers

Description: The basis for qualification of aluminum as a material for use as tubing in Ocean Thermal Energy Conversion heat exchangers is reviewed. Reference is made to compendia of data from tests of aluminum alloys in natural sea water and to applicable service records. Data from these sources were found to be inadequate to either qualify or disqualify aluminum. They serve only to identify the 5052 alloy and Alclad 3003 or 3004 as being worthy of additional testing under conditions more directly related to what will be encountered in OTEC heat exchangers. The principal deficiency of data from long-time tests in natural sea water is that in almost all of these tests the specimens were exposed under static conditions that caused the surfaces to be covered by marine fouling organisms that would not be present in heat exchanger tubes. The tests did not take into account possible effects of periodic mechanical or chemical treatments to remove fouling or chemical treatments (chlorination) to prevent fouling. A current testing program sponsored by the Department of Energy through Argonne National Laboratory is designed to provide the needed data. Limited tests in high velocity sea water have indicated that aluminum tubes would tolerate the velocities under 10 ft (3 m) per second likely to be used in OTEC heat exchangers.
Date: May 1, 1979
Creator: LaQue, F.L.
Partner: UNT Libraries Government Documents Department

Chlorine demand of Savannah River water

Description: Savannah River water used for cooling SRS reactors was tested for chlorine demand and the rate of decay for both free and total residual chlorine on seven quarterly dates between 1986 and 1988. Test conditions included chlorine dosages of 1, 3, and 5 mg/l and a variety of contact times ranging from less than 1 minute to one day. Statistically significant differences were detected in the chlorine demand for the seven dates; however, there was no discernible seasonality to the variation. The chlorine demand, amount of combined residual chlorine formed and the persistence of total residual chlorine following a dose of 5 mg/l was significantly greater on one of the seven sampling dates (February, 1988) compared to all of the other dates. These differences could not be attributed to water temperature, pH, ammonia nitrogen concentration, or the amount of rainfall prior to or during the collection of the cooling water. Except as noted above, dissipation of chlorine was similar among the sampling dates. Most reactions of available chlorine with other constituents in the cooking water occurred in the first minute of contact, although measurable total chlorine residuals generally persisted for 24 hours after the dose had been administered. The results of this study indicate that, with occasional exceptions, a chlorine dose of between 3 and 5 mg/l will provide a free chlorine residual of 1 mg/l in Savannah River water. 14 refs., 3 figs., 4 tabs.
Date: January 1, 1989
Creator: Wilde, E.W.
Partner: UNT Libraries Government Documents Department

Antifouling marine concrete

Description: Various toxic agents were evaluated as the their capability to prevent or inhibit the attachment of marine fouling organisms to concrete. Creosote and bis-(tri-n-butyltin) oxide (TBTO) were impregnated into porous aggregate which was used in making concrete. Cuprous oxide, triphenyltin hydroxide (TPTH), and 2-2-bis-(p-methoxyphenyl)-1,1,1-trichloroethane (methoxychlor) were used as dry additives. Two proprietary formulations were applied as coatings on untreated concrete. Test specimens were exposed at Port Hueneme, CA, and Key Biscayne, FL. The efficacy of toxicants was determined by periodically weighing the adhering fouling organisms. Concrete prepared with an aggregate impregnated with a TBTO/creosote mixture has demonstrated the best antifouling performance of those specimens exposed for more than one year. The two proprietary coatings and the concrete containing methoxychlor, TPTH, and cuprous oxide as dry additives have exhibited good antifouling properties, but they have been exposed for a shorter time. The strength of concrete containing the toxicants was acceptable, and the toxicants did not increase the corrosion rate of reinforcing rods. Organotin compounds were essentially unchanged in concrete specimens exposed 6 1/2 years in seawater.
Date: July 1, 1980
Creator: Vind, H P & Mathews, C W
Partner: UNT Libraries Government Documents Department

Development of plastic heat exchangers for ocean thermal energy conversion. Final report, August 1976--December 1978

Description: Materials and processes have been selected and design information obtained for plastic ocean thermal energy conversion (OTEC) heat exchangers as the result of a program comprising five types of laboratory experiments. Tests to evaluate the chemical resistance of seven commercially available thermoplastics to sea water and several possible working fluids were conducted with emphasis placed on compatibility with ammonia. Environmental rupture tests involving exposure of stressed specimens to sea water or liquid ammonia indicated that the high density polyethylene (HDPE) is the best suited candidate and produced an extrapolated 100,000 hour failure stress of 1060 psi for HDPE. Long term durability tests of extruded HDPE plate-tube panel confirmed that plastic heat transfer surface is mechanically reliable in an OTEC environment. Thermal conductivity measurements of acetylene black filled HDPE indicated that conductivity may be increased by 50% with a 35% by weight filler loading. The permeability coefficient measured for liquid ammonia through HDPE was higher than previous estimates. Test showed that the rate can be significantly reduced by sulfonation of HDPE. A review of biofouling mechanisms revealed that the permeable nature of the plastic heat exchanger surface may be used to control primary biofouling form formation by allowing incorporation of non-toxic organic repellents into the plastic. A preliminary design and fabrication development program suggests that construction of an ammonia condenser test unit is feasible using currently available materials and manufacturing techniques.
Date: January 1, 1979
Creator: Hart, G.K.; Lee, C.O. & Latour, S.R.
Partner: UNT Libraries Government Documents Department

Corrosion and biofouling on the non-heat-exchanger surfaces of an ocean thermal energy conversion power plant: a survey

Description: Of the many foreseeable problems confronting economical ocean thermal energy conversion operation, two major items are the deterioration of the structural and functional components, which prevents efficient operation, and the biofouling of the surfaces, which adds excess weight to the floating ocean platform. The techniques required for effective long-term control of deterioration and corrosion have been investigated actively for many years, and successful solutions for most situations have been developed. For the most part, these solutions can be directly transferred to the ocean thermal energy conversion plant. The majority of problems in these areas are expected to be associated with scale-up and will require some advanced development due to the immensity of the ocean thermal energy conversion platform. Current antifouling control systems are not effective for long-term fouling prevention. Commercially available antifouling coatings are limited to a 3-year service life in temperate waters, and even shorter in tropical waters. However, underwater cleaning techniques and some fouling-control systems presently being used by conventional power plants may find utility on an ocean thermal energy conversion plant. In addition, some recent major advances in long-term antifouling coatings sponsored by the Navy may be applicable to ocean thermal energy conversion. 132 references.
Date: May 1, 1979
Creator: Castelli, V.J. (ed.)
Partner: UNT Libraries Government Documents Department

Micro- and macrofouling in the OTEC program: an overview

Description: The mechanism of formation and environmental factors affecting marine biofouling are reviewed. Methods of biofouling assessment, known and potential biofouling impacts upon plant performance, and control measures applicable to OTEC are also discussed. Areas of uncertainty and the needs for continuing R and D effort to resolve such issues are indicated.
Date: June 1, 1980
Creator: Mitchell, R & Benson, P H
Partner: UNT Libraries Government Documents Department

Toxicity and effects of bromoform on five marine species

Description: Bromoform has been identified as the single most abundant halogenated organic compound produced by the chlorination of marine waters. To determine the potential biological effects of its release into marine waters, short-term toxicity bioassays and 28-day uptake/28-day depuration studies were conducted with five marine species: Protothaca staminea, Mercenaria mercenaria, Crassostrea virginica, Penaeus aztecus, and Brevoortia tyrannus. The bioassay studies indicate that 96-hr LC/sub 50/'s ranged from approximately 7 ppM for B. tyrannus to greater than 40 ppM for P. staminea. The behavior of P. aztecus and B. tyrannus was significantly altered by exposure to bromoform.
Date: June 1, 1979
Creator: Gibson, C.I.; Tone, F.C.; Wilkinson, P. & Blaylock, J.W.
Partner: UNT Libraries Government Documents Department