Download or read book Degradation of Glycol Based Aircraft Deicing Fluids Under Anaerobic Methanogenic Conditions written by Shawn H. Veltman and published by . This book was released on 2000 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics of Anaerobic Degradation of Glycol based Aircraft Deicing Fluids written by Theodore H. Schoenberg and published by . This book was released on 2000 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anaerobic Degradation of Aircraft Deicing Fluid ADF in Upflow Anaerobic Sludge Blanket UASB Reactors and the Fate of ADF Additives written by Thi Tham Pham and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A central composite design was employed to methodically investigate anaerobic treatment of aircraft deicing fluid (ADF) in bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactors. A total of 23 runs at 17 different operating conditions were conducted in continuous mode. The development of four empirical models describing process responses (i.e., chemical oxygen demand (COD) removal efficiency, biomass specific acetoclastic activity, methane production rate, and methane production potential) as functions of ADF concentration, hydraulic retention time (HRT), and biomass concentration is presented. Model verification indicated that predicted responses (COD removal efficiencies, biomass specific acetoclastic activity, and methane production rates and potential) were in good agreement with experimental results. Biomass specific acetoclastic activity was improved by almost two-fold during ADF treatment in UASB reactors. For the design window, COD removal efficiencies were higher than 90%. Predicted methane production potentials were close to theoretical values, and methane production rates increased as the organic loading rate (OLR) was increased. ADF toxicity effects were evident for 1.6% ADF at medium specific organic loadings (SOLR above 0.5 g COD/g VSS/d). In contrast, good reactor stability and excellent removal efficiencies were achieved at 1.2% ADF for reactor loadings approaching that of highly loaded systems (0.73 g COD/g VSS/d). Acclimation to ADF resulted in an initial reduction in the biomass settling velocity. The fate of ADF additives was also investigated. There was minimal sorption of benzotriazole (BT), 5-methyl-1 H-benzotriazole (MeBT), and 5,6-dimethyl-1 H-benzotriazole (DiMeBT) to anaerobic granules. A higher sorption capacity was measured for NP. Active transport may be one of the mechanisms for NP sorption. Ethylene glycol degradation experiments indicated that BT, MeBT, DiMeBT, and the nonionic surfactant Tergitol NP-4 had no significant effects on acidogenesis and methanogenesis at the concentration levels studied. A significant inhibition of acetoclastic activity was observed for NP at 100 mg/L, with acetic acid consumption rate at 38% of that for controls. No evidence for anaerobic degradation of benzotriazole and its derivatives was observed; however, both batch and continuous experiments suggested that anaerobic degradation of NP occurred. Kinetic analysis of operational data obtained for the anaerobic treatment of ADF in UASB reactors indicated that the substrate utilization rate was independent of the reactor biomass concentration. The maximum rate of substrate utilization and the half-velocity constants for ADF treatment were 28.4 g COD/L/d and 648 mg COD/L, respectively. For 1.2% ADF, the biomass yield and endogenous decay coefficients were 0.027 g VSS/g COD and 0.012 d-1 , respectively.

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1999 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publication Water Resources Research Center University of Massachusetts at Amherst written by University of Massachusetts at Amherst. Water Resources Research Center and published by . This book was released on with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Efficient On site Degradation of High Concentration of Spent Deicing Fluids written by and published by . This book was released on 1997 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The on-site treatment of antifreeze compounds and aircraft deicing fluids (ethylene glycol and propylene glycol) will reduce disposal costs, decrease environmental impact, minimize the potential for additional spills/contamination and meet the goals of pollution prevention by reducing the amount of hazardous materials generated. The authors have identified bacteria that can degrade 1-10% glycol waste at room temperatures of ca. 23C. A second subculture was isolated that could degrade glycol waste at ca. 4C.

Download or read book Lift loss Due to the Presence of Anti icing Fluid on a Falcon 20 Aircraft in Out of ground Effect Conditions Rev written by and published by . This book was released on 2005 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes field tests of aircraft takeoff performance with the presence of deicing & anti-icing fluids on the wings. The tests involved an instrumented Falcon 20 aircraft in the takeoff configuration and measurement of aircraft lift loss during takeoff due to the presence of the fluids on the wings. The fluids tested were undiluted ethylene glycol-based Type I deicing fluid, and both ethylene & propylene glycol-based Type IV anti-icing fluids. Two fluid application combinations were tested on the aircraft: Type IV over Type I, and Type IV only. The degradation in the coefficient of lift of the aircraft due to the presence of fluid was determined by taking the difference between the clean wing coefficient of lift condition and a contaminated wing condition at a given angle of attack. Implications of the results for aircraft takeoff operation are discussed.

Download or read book Hazardous and Industrial Waste Proceedings 31st Mid Atlantic Conference written by Nik Nikolaidis and published by CRC Press. This book was released on 1999-06-17 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aircraft De icing anti icing Fluid ADAF laden Wastewater written by Sandra L. Smith-Cunningham and published by . This book was released on 2008 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: ?Pub Inc Airports that operate in cold climates are required by the FAA to de-ice aircraft and runways. The most common method involves the use of glycol-based aircraft de-icing/anti-icing fluids (ADAF). The majority of these fluids contain either propylene or ethylene glycol that act as freezing point depressants, along with additives such as corrosion control inhibitors, surfactants, and wetting agents. Historically, the runoff of spent fluids from aircraft and pavement de-icing/anti-icing operations has been difficult to manage, resulting in significant discharges to surface waters on both a national and global level. Currently, best-practice treatment of airport storm water containing ADAF is geared for glycol-rich wastewaters, with the treatment efficiency being measured by reduction of BOD and nutrient levels in the effluent. The objective of the thesis was to assess whether the traditional parameters (BOD, COD, and pH) most frequently used to monitor the treatment and release of airport stormwater effluent containing de-icing fluids were adequate indicators of the effluent quality. Current literature was used to evaluate the chemistry, environmental fates, persistence in the environment, and toxicity of two classes of compounds, glycols and benzotriazoles. Glycols were shown to be readily degraded in the environment and relatively non-toxic. Benzotriazoles were shown to be resistant to degradation, persistent, and toxic in the environment. The fate of both of these types of compounds was then evaluated in best practice treatment methods for airport stormwater. Glycols were shown to be effectively treated and benzotriazoles were projected to be recalcitrant. The research supports the hypothesis that using BOD, COD, and pH as measures of suitability of return to the environment for treated stormwater containing spent ADAF is inadequate. New additives and more sophisticated ADAFs affect the toxicity of the effluent and require treatment processes that effectively treat all of the constituents of the fluid.

Download or read book DEICING ANTI ICING FLUID AIRCRAFT Propylene Glycol Base written by G-12ADF Aircraft Deicing Fluids and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This specification covers a deicing/anti-icing material in the form of a fluid.

Download or read book DEICING FLUID AIRCRAFT Ethylene Glycol Base written by G-12ADF Aircraft Deicing Fluids and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alternative Aircraft and Pavement Deicers and Anti icing Formulations with Improved Environmental Characteristics written by and published by . This book was released on 2010 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This digest summarizes the results of ACRP Project 02-01, "Alternative Aircraft and Airfield Deicing and Anti-Icing Formulations with Reduced Aquatic Toxicity and Biochemical Oxygen Demand." The research was conducted by a project team consisting of the University of South Carolina, U.S. Geological Survey, Wisconsin State Laboratory of Hygiene, Molecular Knowledge Systems Inc., Infoscitex Corporation, CH2M HILL, and Western Washington University. The digest was prepared from the project final reports authored by George Bowman, Steven R. Corsi, Lee Ferguson, Steven W. Geis, Harris Gold, Kevin Joback, and Dean Mericas.'

Download or read book Water Management written by Iqbal M. Mujtaba and published by CRC Press. This book was released on 2018-11-05 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exponential growth in population and improved standards of living demand increasing amount of freshwater and are putting serious strain on the quantity of naturally available freshwater worldwide. Water Management: Social and Technological Perspectives discusses developments in energy-efficient water production, management, wastewater treatment, and social and political aspects related to water management and re-use of treated water. It features a scientific and technological perspective to meeting current and future needs, discussing such technologies as membrane separation using reverse osmosis, the use of nanoparticles for adsorption of impurities from wastewater, and the use of thermal methods for desalination. The book also discusses increasing the efficiency of water usage in industrial, agricultural, and domestic applications to ensure a sustainable system of water production, usage, and recycling. With 30 chapters authored by internationally renowned experts, this work offers readers a comprehensive view of both social and technological outlooks to help solve this global issue.

Download or read book DEICING ANTI ICING FLUID AIRCRAFT Ethylene Glycol Base written by G-12ADF Aircraft Deicing Fluids and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This specification covers an ethylene-glycol base deicing/anti-icing fluid in the form of a concentrated liquid.

Download or read book Degradation of High Concentrations of Glycols Antifreeze and Deicing Fluids written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Determining Employee Exposure to Ethylene Glycol While Performing Maintenance on an Aircraft Deicing Fluid Collection System written by and published by . This book was released on 2007 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Air monitoring was performed on an aircraft deicing fluid collection system at the Cincinnati/Northern Kentucky International Airport (CNKIA). The goal of the study was to determine employee exposure to ethylene glycol and the target compounds of decomposition as maintenance was performed on the system. The maintenance work involved performing confined space entries to repair and maintain various diversion chambers, pump stations and storage tanks used to collect and convey spent aircraft deicing fluid. The collected deicing fluid during the period of the study was primarily ethylene glycol based. The study included low flow area air sampling of selected diversion valve pits, pump stations and storage tanks for the presence of ethylene glycol as well as ethanol, formaldehyde, and acetaldehyde which are suspected end products of decomposition of ethylene glycol. The study also included the collection of weekly samples using Draeger Tubes to test for ethylene glycol. Samples were collected in the spring, summer and winter months. The results of the study revealed that the target compounds of decomposition were detected in various concentrations throughout the sample study. All results for the decomposition compounds were well below established regulatory and recommended levels. The weekly analysis for ethylene glycol revealed the potential for exposure to ethylene glycol at the diversion valves and to a lesser extent at the deicing pad pump stations during periods of heavy deicing. Ceiling limits for ethylene glycol at deicing fluid collection valves appear to be exceeded during periods of deicing fluid use greater than 750 gallons per day.

Download or read book Development of Improved Aircraft De icing Fluids written by Yuchen Wang and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study the potential of utilizing poly(acrylic acid) (PAA) and polyvinylpyrrolidone (PVP) blends as improved thickening agents of aircraft de-/anti-icing fluids is investigated. Current fluid thickeners commonly comprise PAA homo or co polymers and two examples are investigated in terms of their structure, characteristics, size and the rheological profile as aqueous and solutions in a typical glycol based deicing fluid . The rheological properties of these polymer thickeners are found to be sensitive to composition, electrolyte concentration and pH as well as temperature. The rheological and aerodynamic performances of thickened water glycol mixtures were evaluated under the conditions typically experienced by de icing fluids. A model is also develop ed to simulate the rheological behaviour of the polymer solutions. The model involves consideration of reptation, relaxation of the chains by slippage or loop relaxation, and normal Rouse dynamics is appropriately adapted to reflect the structural changes of the polymer molecules and the consequent pseudoplastic behaviour. The model has helped with development of an understanding of the way in which these polymer systems create the rheological characteristics which are necessary for the action of the fluids in protecting the aircraft during the period it is at the stand and also in the initial stages of taxiing and take off. For the purpose of developing improved thickening materials with proper de icing ability and reduced gel formation tendency, various PV P PAA blends are formulated and rheologically examined together with wind tunnel testing. The gels have a tendency to form insoluble deposits which are capable of jamming the ailerons and flaps during flight. The influences of multiple mono and di valent cations, with which de icing fluids are commonly diluted was investigated. The PVP PAA blends achieve the characteristic rheological properties through a different set of interactions from those of pure PAA and are shown to be less sensitive to electrolyte effects. This study has identified a new potential de-icing fluid system.