Sample records for airstrips

  1. Removal of organic pollutants from 2,2',5,5'-tetrachlorobenzidine (TCB) industrial wastewater by micro-electrochemical oxidation and air-stripping

    A feasible method for treatment of the wastewater from the two-staged neutralization in 2,2',5,5'-tetrachlorobenzidine (TCB) manufacturing processes, a refractory dye intermediate effluents, based on combined micro-electrochemical oxidation or iron-chipping filtration (ICF) and air-stripping reactor (ASR), was developed. On conditions of HRT 1 h, pH 3.0 in ICF and HRT 38 h, gas-liquid ratio 15, pH 6.0-8.65, temperature 26 deg. C in ASR, the overall COD, color, TCB and NH4+-N removal were 96.8%, 91%, 87.61% and 62%, respectively, during the treatment of TCB wastewater from the two-staged neutralization dissolved by methanol. The averaged 18.3%, 81.7% of the total degraded COD, 35.2%, 64.8% of TCB were carried out in ICF and ASR, respectively. NH4+-N removal was finished mainly in ASR. The experimental results indicated that the combined micro-electrochemical oxidation and air-stripping process performed good treatment of COD, color, TCB and NH4+-N removal in TCB wastewater from the two-staged neutralization dissolved by ethanol or acetone, came up the discharge standard in China. But the TCB wastewater from the two-staged neutralization dissolved by methanol should be deeply treated before discharged

  2. Closure Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill with Errata Sheet, Revision 0

    Navarro Nevada Environmental Services


    In Appendix 0, Use Restriction (UR) Form, the drawing of the use restricted area shows the incorrect coordinates for the use restricted area, the coordinates on the drawing do not match the approved UR Form. The coordinates have been verified and this Errata Sheet replaces the drawing of the use restricted area with an aerial photo showing the use restricted area and the correct coordinates that match the approved UR Form.

  3. An Air-Stripping Packed Bed Combined with a Biofilm-Type Biological Process for Treating BTEX and Total Petroleum Hydrocarbon Contaminated Groudwater

    Hong, U.; Park, S.; Lim, J.; Lee, W.; Kwon, S.; Kim, Y.


    In this study, we examined the removal efficiency of a volatile compound (e.g. toluene) and a less volatile compound [e.g. total petroleum hydrocarbon (TPH)] using an air stripping packed bed combined with a biofilm-type biological process. We hypothesized that this system might be effective and economical to simultaneously remove both volatile and less volatile compounds. The gas-tight reactor has 5.9-inch-diameter and 48.8-inch-height. A spray nozzle was installed at the top cover to distribute the liquid evenly through reactor. The reactor was filled with polypropylene packing media for the increase of volatilization surface area and the growth of TPH degrading facultative aerobic bacteria on the surface of the packing media. In air stripping experiments, 45.6%, 71.7%, 72.0%, and 75.4% of toluene was removed at air injection rates of 0 L/min, 2.5 L/min, 4 L/min, and 6 L/min, respectively. Through the result, we confirmed that toluene removal efficiency increased by injecting higher amounts of air. TPH removal by stripping was minimal. To remove a less volatile TPH by commercial TPH degrading culture (BIO-ZYME B-52), 15-times diluted culture was circulated through the reactor for 2-3 days to build up a biofilm on the surface of packing media with 1 mg-soluble nitrogen source /L-water per 1 ppm of TPH. Experiments evaluating the degree of TPH biodegradation in this system are carrying out.

  4. 36 CFR 7.92 - Bighorn Canyon National Recreation Area.


    ... Recreation Area. 7.92 Section 7.92 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... Recreation Area. (a) Aircraft-designated airstrip. (1) Fort Smith landing strip, located at approximate... Canyon National Recreation Area, except in the following areas: (i) In the gated area south of...

  5. 36 CFR 7.70 - Glen Canyon National Recreation Area.


    ... Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... Recreation Area. (a) Designated airstrips. (1) Wahweap, latitude 36°59′45″ N., longitude 111°30′45″ W. (2... within Glen Canyon National Recreation Area, from the Lees Ferry launch ramp downstream to the...

  6. 36 CFR 9.36 - Plan of operations.


    ... surveyor or civil engineer, of a point within a site of operations showing its relationship to the..., and airstrips. The point within the site of operations identified by registered land surveyor or civil engineer shall be marked with a permanent ground monument acceptable to the Superintendent, shall...

  7. Mass transport in physical and biological BTEX removal in a sandy aquifer

    Injection of oxygen and nutrient-amended water facilitated alkylbenzene biodegradation in a sandy aquifer. Pumping recovery wells and air-stripping groundwater further hastened contaminant removal downgradient from the source area. High monitoring well density allowed calculation of a contaminant mass balance using contour plots developed with Surfer reg-sign software. Physical removal (air-stripping) and in situ attenuation appear equally responsible for contaminant removal within this aquifer. Dissolved oxygen data implicate biodegradation as the responsible in situ mechanism with a good stoichiometric fit to BTEX attenuation data. Selective plating confirmed the presence of hydrocarbon-degrading bacteria. Calculations indicate desorption is a major source for recontamination of site groundwater. Contaminant reduction is most pronounced immediately downgradient from reinjection wells. Advective transport and mixing of oxygen in the contaminated zone, rather than microbial kinetics, appears to limit in situ contaminant attenuation

  8. Vulnerability of coastal infrastructure in the Arctic: A focus on the historic settlement on Herschel Island

    Radosavljevic, Boris; Lantuit, Hugues; Fritz, Michael; Overduin, Paul; Krautblatter, Michael


    Herschel Island has a long history of human habitation by indigenous peoples, and whalers who came to the island at the end of the 19th century. Their traces include many archeological sites, and some of the oldest standing buildings in the Yukon, built during the whaling era. The island has been a territorial park since 1987, and it is a candidate to become a UNESCO World Heritage Site. The historic settlement, airstrip, and park infrastructure are located on Simpson Point, a narrow gravelly...

  9. Feasibility of including fugitive PM-10 emissions estimates in the EPA emissions trends report

    The report describes the results of Part 2 of a two part study. Part 2 was to evaluate the feasibility of developing regional emission trends for PM-10. Part 1 was to evaluate the feasibility of developing VOC emission trends, on a regional and temporal basis. These studies are part of the effort underway to improve the national emission trends. Part 1 is presented in a separate report. The categories evaluated for the feasibility of developing regional emissions estimates were: unpaved roads, paved roads, wind erosion, agricultural tilling, construction activities, feedlots, burning, landfills, mining and quarrying unpaved parking lots, unpaved airstrips and storage piles


    Thamm, F.-P.; Brieger, N.; Neitzke, K.-P.; Meyer, M; Jansen, R; Mönninghof, M.


    This paper describes a family of innovative fixed wing UAS with can vertical take off and land – the SONGBIRD family. With nominal payloads starting from 0.5 kg they can take off and land safely like a multi-rotor UAV, removing the need for an airstrip for the critical phases of operation. A specially designed flight controller allows stable flight at every point of the transition phase between VTOL and fixed wing mode. Because of this smooth process with a all time stable flight, ve...

  11. Treatment by water flooding of aquifers contaminated by halogenated solvents; Saneamiento mediante water flooding de acuiferos contaminados por disolventes halogenados

    Navarro Flores, A.


    The treatment of PCE, TCE and DCE contaminated ground water by water flooding and the application to an industrial facility located near of Barcelona, are described in this publications. The installed system comprises three extraction wells located over the edge of contaminant plume, two reinjection wells located near the hypothetic contaminant focus, and a superficial treatment system of contaminated ground water by Air-Stripping (flow rate: 1m''3/h). The modeling of contaminant transport by codes BIOCHOLOR shows the importance of biodegradation process in the mobilization of different contaminants, calculating the disappearance of PCE; TCE and DCE by biodegradation in 61.9%, 64,1% and 72,3% respectively, of total mobilizated mass on a 15 years period. Moreover, modeling allowed the effectiveness of the treatment, indicating a decrease of contaminant concentration of 79.1% , 36.9% and 63.0% for PCE, TCE and DCE. (Author) 19 refs.

  12. Some engineering problems

    H. Williams


    Full Text Available It will help delegates to realize something of the range and magnitude of Service equipment problems if I touch on a few of the many important items which concern the Corps of Engineers in their preparations for war. The Engineers' role in battle is to assist our own forces to maintain their mobility by the passage of obstacles of every, description, the construction of roads and tracks and by meeting the Air Force's requirements airfields and air-strips. Secondly, to deny mobility to the enemy's forces by creating obstacles by demolitions and the destruction of materials, and by the construction of weapon positions and shelters. And lastly to support the administrative machine by supplying water, bulk fuel, power and Engineer stores where required, by meeting the Army's Transportation needs and in numerous other ways dependent on Engineering.

  13. Physical and chemical limnology of Char Lake, Cornwallis Island (75 degrees N lat. )

    Schindler, D.W.; Welch, H.E.; Kalff, J.; Brunskill, G.J.; Kritsch, N.


    Seasonal data for several physical and chemical variables in Char Lake are given. Annual cycles of major solutes are influenced primarily by freeze-thaw cycles. Concentrations of most substances are increased by freezing-out during the winter. Because the lake does not circulate during maximum spring meltwater flow, this freezing-out maintains concentrations in the lake above those in inflow streams. Concentrations of phosphorus and nitrogen in the lake are low throughout the year. Precipitation contains little phosphorus or nitrogen. Input of phosphorus and nitrogen are calculated to be 0.016 and 0.314 grams/square meter, respectively. Retention of nutrients by the lake is lower than in temperate regions, although still quite efficient. With the exception of silica, return of ions from the sediments during winter was found to be negligible. Disturbance of one inflow stream due to airstrip construction caused great increases in concentrations of nitrogen, silica, chloride, sulfate, and bicarbonate in the stream.

  14. Water pollution treatability: a molecular engineering approach

    Strier, M.P.


    Estimated effluent limits for priority nonpesticide organic pollutants, such as phenol and carbon tetrachloride, were developed from the physical-chemical properties (molecular weight, boiling point, and water solubility) and the biochemical oxidizability of these pollutants. These properties were used to develop a separate treatment model (or system) for each pollutant from the following unit treatment processes: steam- or air-stripping; oil/water separation; filtration-diatomaceous or dual media; biochemical oxidation; and activated-carbon adsorption. Pollutants with highest treatability (1.0 jg/1. in the effluent) were generally high molecular weight polycyclic aromatic hydrocarbons and chlorohydrocarbons, e.g., chrysene and benzo(a) pyrene; those with the lowest treatability (100-1000 jg/1. in the effluent) were generally low molecular weight, water-soluble compounds, e.g., acrylo nitrile and vinyl chloride. Solubilities were directly related to the estimated theoretical effluent limitations; partition coefficients and bioconcentration factors were inversely related.

  15. Occupational exposure to airborne particles and other pollutants in an aviation base

    The occupational exposure to airborne particles and other pollutants in a high performance jet engine airport was investigated. Three spatial scales were considered: i) a downwind receptor site, ii) close to the airstrip, iii) personal monitoring. Particle number, surface area, mass concentrations and distributions were measured as well as inorganic and organic fractions, ionic fractions and Polycyclic Aromatic Hydrocarbons. Particle number distribution measured at a receptor site presents a mode of 80 nm and an average total concentration of 6.5 × 103 part. cm−3; the chemical analysis shows that all the elements may be attributed to long-range transport from the sea. Particle number concentrations in the proximity of the airstrip show short term peaks during the working day mainly related to takeoff, landing and pre-flight operations of jet engines. Personal exposure of workers highlights a median number concentration of 2.5 × 104 part. cm−3 and 1.7 × 104 part. cm−3 for crew chief and hangar operator. - Highlights: ► Air quality measures were performed at different spatial scales in an aviation base. ► Exposure to Polycyclic Aromatic Hydrocarbons was estimated. ► Particles at downwind receptor site show a marine origin typical of a coastal site. ► Main exposure peaks are related to pre-flight operations of jet engine aircrafts. ► Crew chief are exposed to highest concentrations even if these were not worrisome. - A negligible impact of a high performance jet engine airport, in terms of airborne particles and other pollutants, was measured through an experimental campaign at three spatial scales.

  16. Engineering geology studies in the National Petroleum Reserve, Alaska

    Kachadoorian, Reuben; Crory, F.E.


    Engineering geology studies were conducted in direct support of the exploration program in the National Petroleum Reserve, Alaska. The studies included laboratory and field tests and observations to address design and construction problems of airfields, roads, drill pads and foundations, and to evaluate their actual performance. Permafrost containing large amounts of near surface ground ice as wedges, masses, and intergranular ice, required that all construction activity not disturb the thermal regime of the ground surface, which could lead to thaw of permafrost and ground subsidence. Summer activity, therefore was not allowable, yet the winter climate was so harsh that winter work was slow and inefficient. To allow summer operations at well sites planned for all year activity, it was necessary to adapt existing techniques for arctic construction and to devise new ones. The design and construction of facilities at the deep exploration wells at Inigok, Tunalik, and Lisburne posed the greatest challenge. These sites, requiring a year or more to drill, could only be attempted if continuous access to drilling and logistic supplies could be assured throughout the year, including the possibility of bringing in another drill rig, in the event of a blowout. Thus all-seasons airstrips were required at these wells. Sufficient quantities of local gravel were not readily available at the Inigok and Tunalik sites to construct the airstrips with the required 6 feet or more of gravel to prevent the underlying permafrost from thawing. Therefore, insulation was used to maintain the subbase of local sands in a continuously frozen state, which in turn was overlain by 15 inches of gravel or sandy gravel. Tests at the U.S. Army Waterways Experimental Station defined the minimum thickness of gravel required above the insulation to provide the desired bearing capacity for the C-130 type aircraft without crushing the insulation. Field testing also included the evaluation of another design

  17. Use of Mini-Sprinklers to Strip Trichloroethylene and Tetrachloroethylene from Contaminated Ground Water.

    Brerisford, Yvette, C.; Bush, Parshall, B.; Blake, John, I.; Bayer, Cassandra L.


    Berisford, Y.C., P.B. Bush, J.I. Blake, and C.L. Bayer. 2003. Use of mini-sprinklers to strip trichloroethylene and tetrachloroethylene from contaminated ground water. J. Env. Qual. 32:801-815. Three low-volume mini-sprinklers were tested for their efficacy to strip trichloroethylene (TCE) and tetrachloroethylene (PCE) from water. Deionized water spiked with TCE and PCE was pumped through a mini-sprinkler supported on top of a 1.8-m-tall. Water was collected in collection vessels at 0.61 and 1.22 m above the ground on support columns that were spaced at 0.61-m intervals from the riser base, and samples were composited per height and distance from the riser. Overall, air-stripping reduced dissolved concentrations of TCE and PCE by 99.1 to 100 and 96.9 to 100%, respectively. Mini-sprinklers offer the advantages of (i) easy setup in series that can be used on practically any terrain; (ii) operation over a long period of time that does not threaten aquifer depletion; (iii) use in small or confined aquifers in which the capacity is too low to support large irrigation or pumping systems; and (iv) use in forests in which the small, low-impact droplets of the mini-sprinklers do not damage bark and in which trees can help manage (via evapotransporation) excess waste water.

  18. Preliminary feasibility and cost analysis of the in-situ microbial filter concept

    In this report the cost of installing and operating an in-situ microbial filter to remediate a site at which the groundwater is contaminated by TCE is estimated and compared against the cost of remediation by a standard pump and treat method. In this microbial filter method, relatively thin vertical filters are installed in the subsurface to intercept contaminant plumes that are being transported by the flowing groundwater. The filters are created by injecting into the subsurface methanotrophic microbes grown in surface bioreactors and allowing them to become attached to the soil. The microbes produce an enzyme (MMO) that fortuitously catalyzes the degradation of TCE into carbon dioxide, water and chloride ions. Because no external energy or carbon source is provided, the microbes remain metabolically active only for a limited time so that the filter needs to be periodically replenished with fresh microbes. Two methods of establishing and maintaining the microbial filter using either vertical or horizontal wells were studied. In the pump and treat method considered for comparison, the groundwater pumped to the surface is first subjected to air-stripping of the liquid-phase volatile organic compound (i.e., VOC) from the groundwater followed by adsorption of the heated vapor-phase VOC by granular activated carbon (i.e., GAC) within a packed-bed filter

  19. Commercial experience in treating U.S. Department of Energy mixed waste

    Chemical Waste Management, Inc. (CWM) has completed numerous mixed waste treatment programs for the US Department of Energy. This paper concentrates on knowledge gained by CWM's experience in performing complex mixed waste projects at US Department of Energy (DOE) federal facilities, and specifically performing projects involving in-situ stabilization. The In-situ treatment of Organic/Uranium Contaminated Soil Demonstration Project was performed in 1992 at the DOE-Gaseous Diffusion Plant, Portsmouth, Ohio. Modified technology using mechanical soil drilling technology to air-strip and degrade organics and inject liquid in-situ stabilization media was verified. Effectiveness of the stabilization process and the resultant product was analyzed, refined, and evaluated for large-scale application. The paper provides an orientation and perspective on the technology, management, and regulatory problems, complexities, and resolutions encountered with treating hazardous and radioactive mixed wastes. The Portsmouth program is summarized, along with accomplishments, corrective actions, and lessons learned. The relevance of lessons learned for international waste treatment programs is also addressed

  20. Contamination source review for Building E3180, Edgewood Area, Aberdeen Proving Ground, Maryland

    Zellmer, S.D.; Smits, M.P.; Rueda, J.; Zimmerman, R.E.


    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review of Building E3180 at the Aberdeen Proving Ground (APG) in Maryland. The report may be used to assist the US Army in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, geophysical investigation, collection of air samples, and review of available records regarding underground storage tanks associated with Building E3180. The field investigations were performed by ANL during 1994. Building,E3180 (current APG designation) is located near the eastern end of Kings Creek Road, north of Kings Creek, and about 0.5 miles east of the airstrip within APG`s Edgewood Area. The building was constructed in 1944 as a facsimile of a Japanese pillbox and used for the development of flame weapons systems until 1957 (EAI Corporation 1989). The building was not used from 1957 until 1965, when it was converted and used as a flame and incendiary laboratory. During the 1970s, the building was converted to a machine (metal) shop and used for that purpose until 1988.

  1. Assessment of the Geometric Quality of SENTINEL-2 Data

    Pandžic, M.; Mihajlovic, D.; Pandžic, J.; Pfeifer, N.


    High resolution (10 m and 20 m) optical imagery satellite Sentinel-2 brings a new perspective to Earth observation. Its frequent revisit time enables monitoring the Earth surface with high reliability. Since Sentinel-2 data is provided free of charge by the European Space Agency, its mass use for variety of purposes is expected. Quality evaluation of Sentinel-2 data is thus necessary. Quality analysis in this experiment is based on comparison of Sentinel-2 imagery with reference data (orthophoto). From the possible set of features to compare (point features, texture lines, objects, etc.) line segments were chosen because visual analysis suggested that scale differences matter least for these features. The experiment was thus designed to compare long line segments (e.g. airstrips, roads, etc.) in both datasets as the most representative entities. Edge detection was applied to both images and corresponding edges were manually selected. The statistical parameter which describes the geometrical relation between different images (and between datasets in general) covering the same area is calculated as the distance between corresponding curves in two datasets. The experiment was conducted for two different test sites, Austria and Serbia. From 21 lines with a total length of ca. 120 km the average offset of 6.031 m (0.60 pixel of Sentinel-2) was obtained for Austria, whereas for Serbia the average offset of 12.720 m (1.27 pixel of Sentinel-2) was obtained out of 10 lines with a total length of ca. 38 km.

  2. Engineered wetlands : an innovative environmental solution

    Engineered wetlands are now considered as an emerging technology for the in situ remediation of hydrocarbon-contaminated soil and waters. Engineered wetlands incorporate a horizontal subsurface flow gravel bed reactor lined with impermeable liners, and are equipped with forced bed aeration systems in order to enhance oxygen delivery to the wetland's aerobic micro-organisms. The wetlands typically emphasize specific characteristics of wetland ecosystems to improve treatment capacities. This article discussed an engineered wetlands installed at a set of pipeline terminals as well as at a former British Petroleum (BP) refinery. The pipeline terminal generated contact wastewater containing BTEX and ammonia, and a subsurface engineered wetland was built in 1998. To date, the 16,0002 foot wetland has treated a flow-equalized input of approximately 1.5 m3 per day of contaminants. At the refinery, a wetland treatment system was designed to treat 6000 m3 of benzene, toluene, ethylbenzene and xylene (BTEX) and volatile organic compounds (VOCs). The treatment site consists of a golf course, river front trails, and a white water kayak course. A cascade aeration system was used for iron oxidation and air-stripping. A soil matrix biofilter was used for passive gas phase benzene removal, as well as for the removal of ferric hydroxide precipitates. It was concluded that engineered wetlands can offer long-term solutions to site remediation challenges. 1 fig

  3. Removal of gasoline volatile organic compounds via air biofiltration

    Volatile organic compounds (VOCs) generated by vapor extraction and air-stripping systems can be biologically treated in an air biofiltration unit. An air biofilter consists of one or more beds of packing material inoculated with heterotrophic microorganisms capable of degrading the organic contaminant of concern. Waste gases and oxygen are passed through the inoculated packing material, where the microorganisms will degrade the contaminant and release CO2 + H2O. Based on data obtained from a treatability study, a full-scale unit was designed and constructed to be used for treating gasoline vapors generated by a vapor-extraction and groundwater-treatment system at a site in California. The unit is composed of two cylindrical reactors with a total packing volume of 3 m3. Both reactors are packed with sphagnum moss and inoculated with hydrocarbon-degrading microorganisms of Pseudomonas and Arthrobacter spp. The two reactors are connected in series for air-flow passage. Parallel lines are used for injection of water, nutrients, and buffer to each reactor. Data collected during the startup program have demonstrated an air biofiltration unit with high organic-vapor-removal efficiency


    Ratnawati Ratnawati


    Full Text Available One of the most dangerous pollutants in wastewater is ammonia. The concentration of ammonia inwastewater discharged from nitrogen fertilizer industry is up to 1500 ppm. Ammonia can be removed byseveral methods such as biological denitrification, air-stripping, and ion exchange. The methods cannotreduce the concentration of ammonia to a low level as required for standard quality of wastewater. Theelectrochemical method has recently attracted attention for the treatment of wastewater containing ammonia.This research is aimed to evaluate the effect of ammonia concentration, current density, and time on theelectrolysis process. Synthetic wastewater containing 500-1500 ppm of ammonia was used in this research.The solution was electrolyzed in a electrolytic cell with Pt/SS electrodes. The experiment was conducted byvarying current density in the range of 5 – 10 mA/cm2 and time from 0 to 105 minutes. The experiment resultsshow that as current density rises, the electrolytic reaction occurs more rapidly. On the other hand, initialconcentration of ammonia has negative effect on the final conversion of ammonia.

  5. Automatic construction of aerial corridor for navigation of unmanned aircraft systems in class G airspace using LiDAR

    Feng, Dengchao; Yuan, Xiaohui


    According to the airspace classification by the Federal Aviation Agency, Class G airspace is the airspace at 1,200 feet or less to the ground, which is beneath class E airspace and between classes B-D cylinders around towered airstrips. However, the lack of flight supervision mechanism in this airspace, unmanned aerial system (UAS) missions pose many safety issues. Collision avoidance and route planning for UASs in class G airspace is critical for broad deployment of UASs in commercial and security applications. Yet, unlike road network, there is no stationary marker in airspace to identify corridors that are available and safe for UASs to navigate. In this paper, we present an automatic LiDAR-based airspace corridor construction method for navigation in class G airspace and a method for route planning to minimize collision and intrusion. Our idea is to combine LiDAR to automatically identify ground objects that pose navigation restrictions such as airports and high-rises. Digital terrain model (DTM) is derived from LiDAR point cloud to provide an altitude-based class G airspace description. Following the FAA Aeronautical Information Manual, the ground objects that define the restricted airspaces are used together with digital surface model derived from LiDAR data to construct the aerial corridor for navigation of UASs. Preliminary results demonstrate competitive performance and the construction of aerial corridor can be automated with much great efficiency.

  6. A Physically Based Model for Air-Lift Pumping

    FrançOis, Odile; Gilmore, Tyler; Pinto, Michael J.; Gorelick, Steven M.


    A predictive, physically based model for pumping water from a well using air injection (air-lift pumping) was developed for the range of flow rates that we explored in a series of laboratory experiments. The goal was to determine the air flow rate required to pump a specific flow rate of water in a given well, designed for in-well air stripping of volatile organic compounds from an aquifer. The model was validated against original laboratory data as well as data from the literature. A laboratory air-lift system was constructed that consisted of a 70-foot-long (21-m-long) pipe, 5.5 inches (14 cm) inside diameter, in which an air line of 1.3 inches (3.3 cm) outside diameter was placed with its bottom at different elevations above the base of the long pipe. Experiments were conducted for different levels of submergence, with water-pumping rates ranging from 5 to 70 gallons/min (0.32-4.4 L/s), and air flow ranging from 7 to 38 standard cubic feet/min (0.2-1.1 m3 STP/min). The theoretical approach adopted in the model was based on an analysis of the system as a one-dimensional two-phase flow problem. The expression for the pressure gradient includes inertial energy terms, friction, and gas expansion versus elevation. Data analysis revealed that application of the usual drift-flux model to estimate the air void fraction is not adequate for the observed flow patterns: either slug or churn flow. We propose a modified drift-flux model that accurately predicts air-lift pumping requirements for a range of conditions representative of in-well air-stripping operations.

  7. Songbird - AN Innovative Uas Combining the Advantages of Fixed Wing and Multi Rotor Uas

    Thamm, F.-P.; Brieger, N.; Neitzke, K.-P.; Meyer, M.; Jansen, R.; Mönninghof, M.


    This paper describes a family of innovative fixed wing UAS with can vertical take off and land - the SONGBIRD family. With nominal payloads starting from 0.5 kg they can take off and land safely like a multi-rotor UAV, removing the need for an airstrip for the critical phases of operation. A specially designed flight controller allows stable flight at every point of the transition phase between VTOL and fixed wing mode. Because of this smooth process with a all time stable flight, very expensive payload like hyperspectral sensors or advanced optical cameras can be used. Due to their design all airplanes of the SONGBIRD family have excellent horizontal flight properties, a maximum speed of over 110 km/h, good gliding properties and long flight times of up to 1 h. Missions were flown in wind speeds up to 18 m/s. At every time of the flight it is possible to interrupt the mission and hover over a point of interest for detail investigations. The complete flight, including take-off and landing can be performed by autopilot. Designed for daily use in professional environments, SONGBIRDs are built out of glass-fibre and carbon composites for a long service life. For safe operations comprehensive security features are implemented, for example redundant flight controllers and sensors, advanced power management system and mature fail safe procedures. The aircraft can be dismantled into small parts for transportation. SONGBIRDS are available for different pay loads, from 500 g to 2 kg. The SONGBIRD family are interesting tools combining the advantages of multi-copter and fixed wing UAS.

  8. Automatic detection of aircraft emergency landing sites

    Shen, Yu-Fei; Rahman, Zia-ur; Krusienski, Dean; Li, Jiang


    An automatic landing site detection algorithm is proposed for aircraft emergency landing. Emergency landing is an unplanned event in response to emergency situations. If, as is unfortunately usually the case, there is no airstrip or airfield that can be reached by the un-powered aircraft, a crash landing or ditching has to be carried out. Identifying a safe landing site is critical to the survival of passengers and crew. Conventionally, the pilot chooses the landing site visually by looking at the terrain through the cockpit. The success of this vital decision greatly depends on the external environmental factors that can impair human vision, and on the pilot's flight experience that can vary significantly among pilots. Therefore, we propose a robust, reliable and efficient algorithm that is expected to alleviate the negative impact of these factors. We present only the detection mechanism of the proposed algorithm and assume that the image enhancement for increased visibility, and image stitching for a larger field-of-view have already been performed on the images acquired by aircraftmounted cameras. Specifically, we describe an elastic bound detection method which is designed to position the horizon. The terrain image is divided into non-overlapping blocks which are then clustered according to a "roughness" measure. Adjacent smooth blocks are merged to form potential landing sites whose dimensions are measured with principal component analysis and geometric transformations. If the dimensions of the candidate region exceed the minimum requirement for safe landing, the potential landing site is considered a safe candidate and highlighted on the human machine interface. At the end, the pilot makes the final decision by confirming one of the candidates, also considering other factors such as wind speed and wind direction, etc. Preliminary results show the feasibility of the proposed algorithm.

  9. The application of in situ air sparging as an innovative soils and ground water remediation technology

    Vapor extraction (soil venting) has been demonstrated to be a successful and cost-effective remediation technology for removing VOCs from the vadose (unsaturated) zone. However, in many cases, seasonal water table fluctuations, drawdown associated with pump-and-treat remediation techniques, and spills involving dense, non-aqueous phase liquids (DNAPLS) create contaminated soil below the water table. Vapor extraction alone is not considered to be an optimal remediation technology to address this type of contamination. An innovative approach to saturated zone remediation is the use of sparging (injection) wells to inject a hydrocarbon-free gaseous medium (typically air) into the saturated zone below the areas of contamination. The contaminants dissolved in the ground water and sorbed onto soil particles partition into the advective air phase, effectively simulating an in situ air-stripping system. The stripped contaminants are transported in the gas phase to the vadose zone, within the radius of influence of a vapor extraction and vapor treatment system. In situ air sparging is a complex multifluid phase process, which has been applied successfully in Europe since the mid-1980s. To date, site-specific pilot tests have been used to design air-sparging systems. Research is currently underway to develop better engineering design methodologies for the process. Major design parameters to be considered include contaminant type, gas injection pressures and flow rates, site geology, bubble size, injection interval (areal and vertical) and the equipment specifications. Correct design and operation of this technology has been demonstrated to achieve ground water cleanup of VOC contamination to low part-per-billion levels

  10. Rehabilitation at Nabarlek: erosion assessment 1999

    Decommissioning work and the rehabilitation at the Nabarlek minesite were completed at the end of 1995. Site description, mining history, environmental management and rehabilitation have been summarised elsewhere (Prendergast et al 1999, Martin 2000, Waggitt 2001). Tailings were buried in the mined-out pit and capped with waste rock. An erosion assessment of the cap design, using a combination of modelling and analogue estimates, indicated that denudation rates on the cap would be -1 (Riley 1995). Riley (1995) suggested minor design modifications to reduce slope length on the pit cap to improve stability and provide structural integrity for several thousand years. Riley (1995) observed that roads were areas of most severe rill development in the Alligator Rivers Region (ARR) and suggested that rill development (0.2-0.3 m depth) on the pit cap would occur in the early stages of adjustment toward equilibrium but not persist in the long term. Consequently, as part of the process of assessing rehabilitation success, erosion at the former minesite was examined by ERISS in August and October 1999. A ground assessment of the perimeter of the evaporation ponds, pit and waste rock dump (WRD), unsealed roads to the north and east of the site and infrastructure area was conducted in August 1999. This survey described, quantified (using a tape and rule) and photographed erosion features. No transects were undertaken. In October 1999, a qualitative (descriptive and photographic) survey of the airstrip, constructed drains, unsealed roads to the west of the site, the pit and WRD was conducted. On this occasion, transects of the WRD and pit were taken but the locations of the transects were not surveyed

  11. Physico-chemical characteristics and environmental exploitation of clinoptilolite Nizny Hrabovec

    The clinoptilolite tuff used in this study, active mineral content of which was measured according to standardized techniques (e.g. X-ray diffraction, ion-exchange, water-vapor desorption) was 60% enriched. Physico-chemical characteristics considered from point of view as water treatment material and compared to siliceous sand and active coal as well as to some foreign clinoptilolite samples, e.g. mineralogical and chemical composition, thermic, alkali- and acid resistance, specific gravity, surface area, porosity, shipping weight, mechanical attrition and powdering survey, adsorption capacities of clinoptilolite towards Cs, Ba, Co, Fe, I, Ag, Zn and ammonium, hydration-dehydration behaviours and selectivity properties from among a major number of cations, have been investigated. Some pilot plant experiences of drinking water treatment with enhanced ammonium concentration on the field facility close to Bratislava and of tannery waste water treatment at Moravian plant using inland clinoptilolite will be presented. Mass-balance recycling loop for regeneration constituents recovery in tannery processing industry (ammonia and chromium) has been proposed and applied during pilot studies (capacity of installations ∼ 1 m3/hr). Iron and ammonium removal by addition of powdered clinoptilolite tuff in chemical coagulation processes for specific polluted surface water purification has been proven, respectively. Economic evaluation of ion-exchange technology by means of clinoptilolite with chemical regeneration and regeneration recovery by air-stripping method and of biological nitrification-denitrification for model hydraulic loading rate 6000 m3/ day was calculated as well as the operating cost of both technologies were compared and will be documented. (author)

  12. Modification of pure oxygen absorption equipment for concurrent stripping of carbon dioxide

    Watten, B.J.; Sibrell, P.L.; Montgomery, G.A.; Tsukuda, S.M.


    The high solubility of carbon dioxide precludes significant desorption within commercial oxygen absorption equipment. This operating characteristic of the equipment limits its application in recirculating water culture systems despite its ability to significantly increase allowable fish loading rates (kg/(L min)). Carbon dioxide (DC) is typically removed by air stripping. This process requires a significant energy input for forced air movement, air heating in cold climates and water pumping. We developed a modification for a spray tower that provides for carbon dioxide desorption as well as oxygen absorption. Elimination of the air-stripping step reduces pumping costs while allowing dissolved nitrogen to drop below saturation concentrations. This latter response provides for an improvement in oxygen absorption efficiency within the spray tower. DC desorption is achieved by directing head-space gases from the spray tower (O2, N2, CO2) through a sealed packed tower scrubber receiving a 2 N NaOH solution. Carbon dioxide is selectively removed from the gas stream, by chemical reaction, forming the product Na 2CO3. Scrubber off-gas, lean with regard to carbon dioxide but still rich with oxygen, is redirected through the spray tower for further stripping of DC and absorption of oxygen. Make-up NaOH is metered into the scrubbing solution sump on an as needed basis as directed by a feedback control loop programmed to maintain a scrubbing solution pH of 11.4-11.8. The spent NaOH solution is collected, then regenerated for reuse, in a batch process that requires relatively inexpensive hydrated lime (Ca(OH)2). A by-product of the regeneration step is an alkaline filter cake, which may have use in bio-solids stabilization. Given the enhanced gas transfer rates possible with chemical reaction, the required NaOH solution flow rate through the scrubber represents a fraction of the spray tower water flow rate. Further, isolation of the water being treated from the atmosphere (1




    The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg/m{sup 3} (2000 {micro}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance of an air-stripping tower. Ten extraction wells and three injection wells operate at a combined rate of approximately 0.017m{sup 3}/s (17.03 L/s). In 2005, groundwater from two of the extraction wells (299-W15-765 and 299-W15-44) began to show concentrations greater than twice the maximum contaminant level (MCL) of Tc-99 (33,309 beq/m{sup 3} or 900 pCi/L). The Tc-99 groundwater concentrations from all ten of the extraction wells when mixed were more than one-half of the MCL and were slowly increasing. If concentrations continued to rise and the water remained untreated for Tc-99, there was concern that the water re-injected into the aquifer could exceed the MCL standard. Multiple treatment technologies were reviewed for selectively removing Tc-99 from the groundwater. Of the treatment technologies, only ion exchange was determined to be highly selective, commercially available, and relatively low in cost. Through research funded by the U.S. Department of Energy, the ion-exchange resin Purolite{reg_sign} A-530E was found to successfully remove Tc-99 from groundwater, even in the presence of competing anions. For this and other reasons, Purolite{reg_sign} A-530E ion exchange resin was selected for treatability testing. The treatability test required installing resin columns on the discharge lines from extraction wells 299-W15-765 and 299-W15-44. Preliminary test results have concluded that the Purolite{reg_sign} A-530E resin is effective at removing Tc-99 from groundwater to

  14. Tundra Rehabilitation in Alaska's Arctic

    Lynn, L. A.


    Oil exploration in Alaska's Arctic has been conducted for more than 40 years, resulting in over 3,640 ha of gravel fill placed for roads, pads, and airstrips to support the industry. Likewise, tundra disturbance from burying power lines and by tundra vehicle travel are also common. Rehabilitation of disturbed sites began around 2002, with well over 150 ha that has been previously treated or is currently being rehabilitated. Two primary goals of rehabilitation efforts have been 1) revegetation by indigenous species, and 2) limiting thermokarst. Early efforts were concerned that removing gravel and having exposed bare ground would lead to extensive subsidence and eolian erosion. Native grass cultivars (e.g. Poa glauca, Arctagrostis latifolia, and Festuca rubra) were seeded to create vegetation cover quickly with the expectation that these grasses would survive only temporarily. The root masses and leaf litter were also expected to trap indigenous seed to enhance natural recolonization by indigenous plants. Due to the remote location of these sites, many of which are only accessible by helicopter, most are visited only two to three times following cultivation treatments, providing a limited data pool. At many sites, the total live seeded grass cover declined about 15% over the first 5¬-6 years (from around 30% to 15% cover), while total live indigenous vascular cover increased from no or trace cover to an average of 10% cover in that time. Cover of indigenous vascular plants at sites that were not seeded with native grass cultivars averaged just less than 10% after 10 years, showing no appreciable difference between the two approaches. Final surface elevations at the sites affect local hydrology and soil moisture. Other factors that influence the success of vegetation cover are proximity to the Arctic coast (salt effects), depth of remaining gravel, and changes in characteristics of the near-surface soil. Further development of rehabilitation techniques and the

  15. A Giant of Astronomy and a Quantum of Solace - James Bond filming at Paranal


    our director, Marc Forster and production designer, Dennis Gassner, both for its exceptional design and its remote location in the Atacama desert. It is a true oasis and the perfect hide-out for Dominic Greene, our villain, whom 007 is tracking in our new James Bond film." In addition to the shooting at the Residencia, further action will take place at the Paranal airstrip. The film crew present on Paranal includes Englishman Daniel Craig, taking again the role of James Bond, French actor Mathieu Amalric, leading lady Olga Kurylenko, from the Ukraine, as well as acclaimed Mexican actors, Joaquin Cosio and Jesus Ochoa. This cast from across Europe and Latin America mirrors the international staff that works for ESO at Paranal. After leaving Paranal at the end of the week, the film crew will shoot in other locations close to Antofagasta. Other sequences have been filmed in Panama and, following the Chilean locations, the unit will be travelling to Italy and Austria before returning to Pinewood Studios near London in May. QUANTUM OF SOLACE will be released in the UK on 31 October 2008, and in the US and internationally on 7 November 2008.

  16. Space Radar Image of Rabaul Volcano, New Guinea


    This is a radar image of the Rabaul volcano on the island of New Britain, Papua, New Guinea taken almost a month after its September 19, 1994, eruption that killed five people and covered the town of Rabaul and nearby villages with up to 75 centimeters (30 inches) of ash. More than 53,000 people have been displaced by the eruption. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 173rd orbit on October 11, 1994. This image is centered at 4.2 degrees south latitude and 152.2 degrees east longitude in the southwest Pacific Ocean. The area shown is approximately 21 kilometers by 25 kilometers (13 miles by 15.5 miles). North is toward the upper right. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). Most of the Rabaul volcano is underwater and the caldera (crater) creates Blanche Bay, the semi-circular body of water that occupies most of the center of the image. Volcanic vents within the caldera are visible in the image and include Vulcan, on a peninsula on the west side of the bay, and Rabalanakaia and Tavurvur (the circular purple feature near the mouth of the bay) on the east side. Both Vulcan and Tavurvur were active during the 1994 eruption. Ash deposits appear red-orange on the image, and are most prominent on the south flanks of Vulcan and north and northwest of Tavurvur. A faint blue patch in the water in the center of the image is a large raft of floating pumice fragments that were ejected from Vulcan during the eruption and clog the inner bay. Visible on the east side of the bay are the grid-like patterns of the streets of Rabaul and an airstrip, which appears as a dark northwest-trending band at the right-center of

  17. Space Radar Image of Raco, Michigan, ecological test site


    This is an X-band image of seasonal changes at the ecological test site of Raco, Michigan, located south of Whitefish Bay on Lake Superior. The image is centered at about 46 degrees north latitude and 85 degrees west longitude. This image was acquired by the X-band Synthetic Aperture Radar onboard the space shuttle Endeavour on April 10th, 1994, and on October 1, 1994. The areas shown in red correspond to the April 10th data; the areas in blue correspond to data acquired on October 1, 1994; green indicates the ratio of data acquired on April 10 and October 1, 1994. The area shown is 22.7 kilometers by 53 kilometers (14 miles by 33 miles). Lake Superior in the upper right was frozen in April and had small waves (ripples) on its surface in October. The land area contains mostly forests and, to a lesser extent, agricultural regions. In April the area was covered in wet snow. By October, there agricultural areas were covered with grass. Vegetation and soils were moist due to rainfalls three days before the data was acquired on October 1, 1994. The bright light green/yellow tones in the lower half of the image show the stronger reflections of the snow-covered agricultural fields. The pinkish color corresponds to the coniferous and deciduous forests. The green area represents red pines. These trees are smaller than the surrounding forest cover and allow more radar penetration. The area is green because the radar is sensing the surface, which undergoes great change from snow to grass and fern undergrowth between April and October. The bright green triangle in the upper half of the image is an old airstrip, while the modern airport can be seen on the bottom right side of the image. The Raco site is an important location for monitoring seasonal changes and future global change because it is situated at the ecological transition zone between the boreal forests and the northern temperate forests. This transitional zone is expected to be ecologically sensitive to anticipated

  18. Potential applications of synthetic aperture radar (SAR) satellite imagery to nuclear safeguards

    Particular strengths and weaknesses of synthetic aperture radar (SAR) satellite imagery are highlighted and potential applications of this unique all-weather, day/night information source to safeguards are described and illustrated by examples. Examples are drawn from the literature and from experiments carried out under the Canadian Safeguards Support Program on proxy sites. Many new unclassified high resolution SAR satellites will soon be launched, and their impact on the state-of-the-art in satellite imaging for safeguards is estimated. Today, all unclassified SAR satellites in regular operation are C-band, using approximately 5.3 gigahertz centre frequency for radar pulse emissions. Resolution is limited to 9 metres. Within one year 3 m resolution C-band and 1 m resolution X-band (specifically 9.6 gigahertz) systems will be available. This divides our summary of applicable techniques into the concrete and proven (for low resolution C-band) and the intriguing but more speculative (for 1m X-band). The resolution of current C-band sensors such as RADARSAT-1 is insufficient to permit identification of any but the largest of structures (roads, dams, large ships, airstrips, bridges, large buildings). RADARSAT-2 will have significantly improved resolution (3m), but identification remains out of reach for many targets, and the identification possible with high resolution optical systems such as Quickbird or IKONOS cannot be matched. C-band SARs have a particular strength, however, when used in a monitoring mode where multiple observations over time can be combined using sophisticated comparative methods. Combining multitemporal observations using colour composites is a simple but effective method that has been used for many years with all types of imagery. SAR-specific techniques which rely upon the inherent radar phase measurements (so-called coherent, or interferometric techniques) are much more involved. When conditions are favourable these techniques can render