VOLUME Objective 2 of the project work plan was to: 3.2. Major Inputs and Outputs of the Bioreactor

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1 VOLUME 3 Deliverables to meet work plan objective 2: Design and operate the bioreactor in a manner to control and measure all major inputs and outputs 3.1. Objective 2 of the project work plan was to: Design and operate the bioreactor in a manner to control and measure all major inputs and outputs safely. The work plan identified the following methodology to meet objective 2: A major limitation in the data collected from a full-scale bioreactor project to date is the inability to capture and measure all inputs and outputs. This is especially true with gas emissions in both aerobic and anaerobic systems. The landfill bioreactor at the NRRL will be equipped with a geomembrane cap to collect gas emissions from the surface. The leachate collection system will be utilized to monitor gas inputs and outputs. Leachate production will be measured on the basis of each individual leachate collection line. All landfill inputs will be measured using state of the art techniques. Thus all major inputs and outputs will be measured to the best of the project team s ability Major Inputs and Outputs of the Bioreactor A bioreactor landfill should be operated as a waste processing facility and therefore it is necessary to accelerate the biological, chemical and hydrologic processes occurring within the landfill to rapidly transform and degrade organic waste. The increase in waste degradation and stabilization is accomplished by adding liquid and air to enhance microbial processes; also by controlling and measuring major inputs and outputs. This volume provides the fundamentals of controlling major input and output parameters that are instrumental in the successful operation of any bioreactor. The major inputs of the operation at the bioreactor sites are the daily waste filling, compaction, and intermediate covers, leachate recirculated, and air injection. Since the NRRL bioreactor was retrofitted on an existing landfill, the waste and daily cover has not been modified to accelerate or enhance the waste degradation process. This report provides the various steps undertaken in design and operation of the leachate and air injection systems of the NRRL bioreactor; likewise, the method of measuring various input parameters are well defined in this section. The design of the gas collection system for uniformly collecting gas from the surface of the landfill and the leachate collection system is also discussed. The major outputs in the operation of the bioreactors are the gas and leachate generated, settlement of the landfill, moisture content, and temperature of the waste. This report discusses innovative techniques that have been implemented in measuring the outputs in the operations of the bioreactor. Innovations such as the weir box assembly to measure the flow rate from each manhole, GEM meter for measuring the gas composition and flow rate, MTG and TDR sensors to measure the moisture content and temperature, surveying using global positioning system, and several others.

2 3.3. Major Input Parameters For The Operation Of A Bioreactor Moisture Addition The single most important and cost-effective method that provides controls and process optimizations is through the addition of leachate for accelerated and efficient solid waste degradation. In addition, moisture aids in controlling the temperature within the landfill, so moisture addition can be adjusted to keep the bioreactor within the ideal thermophilic conditions (113 F -149 F). The type of leachate recirculation system and the method of operation are selected after appropriate consideration of the project goals related to moisture distribution, minimizing environmental impact, and full regulatory compliance. Leachate recirculation in a landfill can be done in several ways including pre-wetting, spraying, surface ponds, horizontal infiltration systems, and vertical injection wells. Vertical injection wells was chosen for leachate recirculation at the NRRL because they can be retrofitted into an already existing landfill; they are able to inject relatively large quantities of leachate, offer minimum exposure pathways, provide good all-weather performance, and can be built after the placing the final lift of waste on the cell of a landfill. Approximately 10 acres were dedicated as an active bioreactor area. At NRRL, 45 vertical injection well clusters are arranged at approximately 50 ft intervals with monitoring wells flanking them as shown in Figures 3.1 and 3.2. A detailed description of the vertical injection wells and the construction these well clusters are described in volume 2 of this report and in the dissertation of Jain, (2005). The injection wells provide either leachate or air to the waste mass depending on the type of wellhead connections fit to the systems. Monitoring wells contain MTG sensors that collect moisture and temperature data periodically and uniformly within the landfill. Figure 3.1. Vertical And Monitoring Well Clusters At NRRL 3-2

3 Monitoring wells Leachate manifold Vertical wells cluster Air manifold Figure 3.2. Vertical Well Clusters and Monitoring Wells The total volume of liquid needed to reach the target moisture content provides a benchmark to assess the percentage progress of the liquid introduction operation. However, specification of flow rate, the volume of liquids that should be added over a given duration, is necessary for detailed design of a liquid introduction system, and for the operation of the system. Several factors affect the rate at which liquid should and can be injected. For the NRRL bioreactor, the rate of leachate recirculation was calculated based on maximum leachate injection rates, aerobic degradation of waste, impact on leachate collection system, and water balance within the landfill. Maximum Leachate Injection Rate Leachate injection was proposed in a phased manner to avoid the possibility of seeping and a potential increase in the head pressure of the liner. Field capacity within the waste volume was computed to be 23,700,000 gallons. Operating the pump for 100 gpm for 12 hours, a day yields an equivalent of a 72,000 gallons per day injection rate, prior to reaching the field capacity in approximately 250 days. A safety factor of 20% is applied to the calculation. The revised field capacity of 18,960,000 gallons and the revised injection rate prior to field capacity was estimated to be57,600 gpd. A step-by-step calculation is presented in the permit application in Appendix A of this report. Aerobic Degradation Of Waste Aerobic degradation of waste causes stripping of the moisture from waste mass is a consequence of the air injection. A flow rate of roughly 140 gpm over a 2.5 acre portion of the bioreactor is estimated to re-supply the moisture stripped from the aerobic bioreactor as stated in the permit application, which can be found in Appendix A of this report. 3-3

4 Impact On Leachate Collection System The impact of added liquids on the leachate collection and the liner also plays a major role with respect to the flow rate of liquid introduction. Although it is assumed that all of the recirculated leachate will be utilized in biological transformations of landfilled waste, contrarily, the leachate drainage is normal. To demonstrate full compliance with the 12-inch leachate head requirement, hydrodynamic mechanisms within the waste mass and leachate drainage layer, were mathematically modeled using Moore s equation as modified by J.P. Giroud s and McEnroe s equation. Projection on the horizontal plane, each leachate-collection, and lateral drainage basin is approximately 795 feet long and 100 feet wide. Resulting calculations using the Moore equation modified by Giroud, estimated the allowable impingement, within the leachate drainage layer, is 6395 gpd per lateral basin; the Moore equation modified by McEnroe calculated 7521 gpd per lateral basin. It was recommended that recirculation of the leachate will result with the impingement measured at each level, remains less than 6395 gallons per day, maintaining less than 1 ft of head pressure on the liner. Details of these calculations are presented with the permit application and located in Appendix A, of this report. Water Balance Using The HELP Model Although the HELP model is commonly accepted as a mathematical simulation of the water balance within a landfill, it was found to be an inapplicable modeling tool due to the uniqueness of the bioreactor. First, the landfill is capped with an exposed geomembrane system that is not simulated by HELP. Second, a key feature of the HELP model is its ability to estimate the water balance in a landfill as the result of local storm events; since the bioreactor is capped with a geomembrane, the impingement resulting from rainfall is negligible. The geomembrane is designed to be impervious to escaping fluids; thus, in the reverse scenario itis significantly effective and vastly under-utilizes this feature. Third, HELP does not have a compatible leachate recirculation feature. This model will only allow for recirculation of a small percentage of impingement collected from the drainage layer; leachate is again minimized due to the landfill cap. Fourth, the model only simulates typical anaerobic landfills, whereas the bioreactor location additionally operates under aerobic conditions at its designated cell site Air Addition In order to run the bioreactor aerobically, it is important to know the flow rate of air addition for gauging the blower sizes. The purpose of this calculation is to determine the air and water required to run ¼ of the Union County New River, landfill bioreactor under aerobic conditions. The following table illustrates the general composition of waste received at this site. 3-4

5 Table 3.1. Composition Of Waste Waste Type Percent of Total Inorganic fraction Paper Plastic Metal Glass Organics Household Hazardous Other Waste Total Theoretical Volume Of Air Required Two particular scenarios were investigated for air requirements and exit gas generation of the Union County New River Landfill bioreactor. Waste Chemical Composition Air Required (ft 3 /ton waste) Exit gas Volume (ft 3 /ton waste) Air Flow Required (SCFM) C 16 H 27 O 8 N C 6 H 10 O Exhaust Gas Flow (SCFM) Table 3.2. Air Flow Required And Exhaust Gas Generated For The Aerobic Bioreactor Waste Chemical Composition Air Flow Required (SCFM) Exhaust Gas Flow (SCFM) Waste Chemical Composition Air Flow Required (SCFM) C 16 H 27 O 8 N C 16 H 27 O 8 N C 6 H 10 O C 6 H 10 O

6 If ¼ of the landfill is being operated under aerobic conditions then the flow should be as follows: Waste Chemical Composition Air Flow Required (SCFM) Exhaust Gas Flow (SCFM) C 16 H 27 O 8 N C 6 H 10 O Calculating These Flow Requirements - The Water Budget Is: Waste Chemical Composition Water Generated (gpd) Water Stripped (gpd) C 16 H 27 O 8 N C 6 H 10 O Water injection required (gpd) Hence, to operate the bioreactor landfill aerobically with a volume of 240,660 yd 3, the bioreactor would require: 1550 scfm of air injected into the landfill 2350 gallons of water per day injected into the landfill 1480 scfm of the exhaust gas flow The results assume an ideal system where water and oxygen transfer rate is 100% effectively exchanged and an optimal bacteria-growing environment is maintained. These calculations also assume that the landfill is at field capacity. Sizing of the Blowers The calculations results indicated that 1500 scfm of air would be required. Two 50hp positive displacement air blowers were installed at the flare station to handle the anticipated air injection requirements as shown in Figure 3.3. Each blower can supply a steady design flow rate of 750 scfm to stand against the 10-psibackpressure from the landfill. On the blower exhaust, a heat exchanger was installed to maintain the air injection temperatures. 3-6

7 Candle-Stick Flare Three Centrifugal Gas Extractors Two Air Blowers for air injection Knock-out and De-mister Figure 3.3.Flare Station At The NRRL Appendix C. Theses and Dissertations Kim, H. (2005). Comparative studies of aerobic and anaerobic landfills using simulatedlandfill lysimeters. Ph.D. Dissertation. University of Florida, Gainesville, FL. Powell, J. (2005). Trace gas quality, temperature control and extent of influence from air addition at a bioreactor landfill. Masters Thesis, University of Florida, Gainesville, FL. Jain, P. (2005). Moisture addition at bioreactor landfills using vertical wells: mathematical modeling and field application. Ph.D. Dissertation. University of Florida, Gainesville, FL. Timmons, J. (2004). Total earth pressure cells for measuring loads in a municipal solid waste landfill. Masters Project, University of Florida, Gainesville, FL. Jonnalagadda, S. (2004). Resistivity and time domain reflectrometry sensors for assessing in-situ moisture content in a bioreactor landfill. Master's Thesis, University of Florida, Gainesville, FL.Appendix D. Peer-Reviewed Journal Articles And Conference Proceedings Jain, P., Powell, J., Townsend, T., Reinhart, D. (2005) Air permeability of waste in a municipal solid waste landfill. Journal of Environmental Engineering, ASCE, 131(11), Jain, P., Kim, H., and Townsend, T. (2005). Heavy metal content in soil reclaimed from a municipal solid waste landfill. Waste Management, 25, Reinhart, D. McCreanor, P, Townsend, T. (2002). The bioreactor landfill: Its status and future. Waste Management and Research, 20,

8 3.4 Operation of the Bioreactor More than 6.28 million gallons of leachate and groundwater has been added using the vertical well system since December The leachate generated through other cells at this site was also added to the bioreactor. Groundwater was used to supplement leachate for times when enough leachate was not available. Figure 3.4 presents the cumulative volume of liquid (leachate and groundwater) added over the duration of the study. Approximately 1millon gallon of groundwater was used for moisture addition. 7 6 Total liquid Leachate Volume ( 10 6 gallons) Ground water Days (12/31/02 to 4/30/07) Figure 3.4. Cumulative Volume Of Liquid Addition Each of the 45 vertical well clusters contains 20 ft, 40 ft, and, 60 ft deep wells. Leachate was injected simultaneously in all the vertical wells of the vertical well clusters as shown in Figure 3.5. Initially leachate was added in single vertical well clusters. After gaining enough operation experience leachate was simultaneously added in several vertical well clusters. Performance evaluations of these vertical well clusters are presented in detail in the Jain (2005) dissertation in appendix C and in Jain (2005), Performance evaluation of vertical wells for landfill leachate recirculation in appendix D. 3-8

9 Figure 3.5. Leachate Recirculation in all Three Wells in a Cluster The suspended solids (including small pieces of plastic material from the pipe installation) in leachate frequently clogged water meters and thus considerably reduced the leachate flow rate into the wells during the preliminary field tests. A self-cleansing, 0.3-mm screen filter with an adequate design flow rate was installed at the inlet of the moisture distribution manifold as shown in Figure 3.6. This filter was flushed on daily basis, disassembled, and cleaned when the system was stopped for scheduled preventative maintenance. The flexible hose that was used to connect the injection wells to the distribution manifold was transparent and encountered clogging due to biological growth over prolonged periods causing a reduction of the flow rates. The recommendation is that in future designs the hoses used should be flexible, opaque hose with a smaller diameter, in order to minimize algae growth in the system. 3-9

10 Figure 3.6. Self-Cleansing 0.3-mm Screen Filter To Avoid Clogging During Leachate Recirculation The most evident disadvantage of the vertical wells for leachate recirculation is the inability to add leachate under pressure. In a vertical well system, the maximum injection pressure of the leachate realized at the bottom of the vertical well is equal to the depth of the vertical well. Any increase in this pressure can cause the leachate to migrate from the outer periphery of the vertical well to the top of the landfill; the resulting issue is the formation of seeps, where leachate channels its way through the slope side of the cell. The occurrence of seeps in this case, was indicated by soft spots below the geomembrane cap and near the well cluster, when the level of leachate in these wells rose above the surface of the landfill. Due to seeping, the leachate can enter the storm-water pond if the liquid drains through the side-slope as shown in Figure 3.7. The side-slope seeps were more frequently observed while testing was in progress in the shallow well. 3-10

11 Figure 3.7. Seeping From The Surface Of The Landfill Due to the leachate recirculation and landfill gases that build up in these vertical wells, the pressure causes some of the leachate to flow back from the vertical wells with high pressure as shown in Figure 3.8. Figure 3.8. Leachate Back Flow From Vertical Wells 3-11

12 Appendix C. Theses And Dissertations Jain, P. (2005). Moisture addition at bioreactor landfills using vertical wells: mathematical modeling and field application. Ph.D. Dissertation. University of Florida, Gainesville, FL. Appendix D.Peer-reviewed Journal Articles and Conference Proceedings Jain, P., Townsend, T., and Reinhart, R. (2005). Experiences from the operation of a fullscale bioreactor landfill in Florida. Solid Waste Association of North America s Wastecon 2005, Austin, TX, September 27-29, Jain, P.,Farfour, W., Jonnalagadda, S., Townsend, T., and Reinhart, D. (2005). Performance evaluation of vertical wells for landfill leachate recirculation. Proceedings of Geo Frontier 2005, ASCE conference, January 24-26, 2005, Austin, TX. 3.5.Major Output Parameters For The Operation Of A Bioreactor Leachate Generated At The Leachate Collection System Within the landfill, biodegradable materials can be broken down by the aerobic or anaerobic processes, which involve the sequential breakdown of complex organic materials by several interacting groups of microorganisms. The degradation process ensues through a number of phases as different populations of microorganisms are established. The process of biodegradation also referred to as stabilization has been discussed in Reinhart et al. (2000 and 2002). Hence, it is essential to know the quality and quantity of the leachate generated in order to understand the effective rate of the degradation of waste Measurement Of Leachate Quantity The leachate collection system at the NRRL bioreactor was described in Volume 2 of this report. Leachate generated from individual manholes is gravity-drained to the main wet well. This wet well contains a magnetic flow meter to measure the cumulative volume of leachate generated from Cells 1 and 2 of the bioreactor as shown in Figure 3.9. The leachate flow rate from the individual manholesis measured using a V-notch Weir box installed in each manhole as shown in Figure 3.10 and fully described in Volume 2.Leachate samples were collected from the manholes on a weekly basis using a submersible pump located on the Weir box unit,pictured in Figure

13 Figure 3.9.MagneticFlow Meters Measure The Cumulative Volume Of Leachate From The Leachate Collection System Leachate from leachate collection Leachate sampling pump V notch Weir box Figure A Weir Box Assembly Leachate from the collection system is stored in an aeration pond. This leachate is then recirculated back in the landfill. Magnetic flow meters are used to measure the flow rate of the leachate recirculated. Displacement water meters measure the flow rate entering each vertical wellas shown in Figure 3.5 and

14 Figure Displacement Water Meters For Measuring flow Rate Through Individual Vertical Wells Measurement Of Leachate Quality Leachate was analyzed for dissolved oxygen, ph, and, conductivity during the hour prior to leachate sampling. After this initial sample analysis, 15 ml of leachate was preserved with sulfuric acid and placed in acid-rinsed, high-density polyethylene (HDPE) bottles for further analysis of chemical oxygen demand (COD), total organic carbon (TOC), volatile, fatty-acids (VFA), and ammonia. For metal analysis, 50 ml of leachate was preserved with concentrated nitric acid and stored at 4 C. Table 3.2 summarizes the parameters and methods used for each analysis. 3-14

15 Table 3.2.Leachate Parameter Analysis Parameters Method Parameters Method Alkalinity Standard Method 2320B Ammonia Standard Method 4500-D BOD Standard Method 5210B COD HACH 2720 Conductivity Standard Method 2510 ph Standard Method 4500-H+ TOC EPA SW846, Method 9060 Sulfide HACH 8131 Sulfate, Fluoride and Chloride Sodium VFA Fluoride and Chloride EPA SW846, Method 9056 EPA SW846, Method 9060A VFA analysis method using GC. Innocente et al.(2000) 3.5.2Landfill gas generated from the surface of the landfill and from the manholes The presence of gas in the waste media can have a negative impact on liquids flow in the waste for two reasons. First, the volume of pore spaces available for liquids storage and movement decreases as gas occupies a fraction of the available pore spaces. Second, the hydraulic conductivity of the media decreases because of positive gas pressure. In order to minimize the impact of landfill gas on the design and operation of a bioreactor landfill, an efficient removal of gas from the landfill is required. The bioreactor at NRRL was divided uniformly into several sections. A gas collection trench was built in each section. The trench was provided to improve gas collection efficiency and manage leachate that enters the gas collection system. There were thirty-one (31) gas collection wells were built on the geomembrane cap surface to extract gas from the gas collection trench when constant negative pressure is applied from the blower station as shown in Figure Also negative pressure within the geomembrane assists in keeping the geomembrane cap from lifting as the result of wind pressure. These gas collection wells consist of a reinforcing collar, thermometer, and orifice plate for measuring gas composition and flow rate. The details of the gas collection system are present in volume 2 of this report. 3-15

16 Figure Gas Collection System Sizing of the blowers Anaerobic bioreactors generate Landfill gas (LFG, principally methane and carbon dioxide) earlier in the process and at a much higher rate than the conventional landfill. Bioreactor LFG is generated over a shorter period because the LFG emissions begin early and decline as the accelerated decomposition process depletes the source waste. Hence, it is essential to estimate the landfill gas emissions at initiation of the bioreactor demonstration project and determine the size of the blowers. The EPA landfill gas emissions model version 2.0 was used to calculate the methane gas generation rate. According to the calculations, Cells 1 and 2, they were anticipated to generate a maximum of 1825 scfm total landfill gas, which, when they are summed up equate to,1480 scfm for the 2.5 acre aerobic area, with the remainder of, 345 scfm for the 7.5 acre anaerobic area. The gas collection system consists of two 20 hp positive displacement type gas extractors. Each gas extractor is capable of providing a range of flow rates up to 1500 scfm under a pressure drop of approximately 2 psi. One more gas extractor was also installed as a back-up system. A gas collection knockout and de-mister was installed at the inlet of the blower station to remove the moisture caught in the gas collection stream. A detailed Figure of the flare station is shown in Figure 3.4. Even leachate collection system generates good quality and quantity of gas. So the manholes were connected to the main gas collection system. 3-16

17 Measurement of gas production and control of gas quality The quality of gas collected from the gas wells is an indicator for aerobic or anaerobic activity going on in the bioreactor. Anaerobic activity gas contains high methane and carbon dioxide content and aerobic activity gas contain high carbon dioxide content. The GEM2000 designed by LANDTEC was used to monitor landfill gas (LFG) extraction systems as shown in Figure This instrument sample and analyze the Methane, Carbon Dioxide and Oxygen content of LFG and the flow rate of gas produced. The readings are displayed and can be stored in the instrument and downloaded to a personal computer for reporting, analyzing, and archiving. The GEM meter is connected to the orifice plate of each gas well to determine the quality and quantity of gas produced. The quality of gas produced can be controlled adjusting the amount of vacuum pulled from each gas well. Gas readings were taken daily from the flare station and weekly from individual gas wells. Figure 3.13 GEM2000 to monitor landfill gas The Figure3.14 indicates that the bioreactor is producing about 800 scfm of landfill gas with 200 scfm of methane. The graph also indicates that the gas quantity has improved significantly since starting leachate recirculation in Details on the gas production can be seen in volume 6 of this report. Figure 3.15 indicates that most of the gas is produced from the sideslope of the bioreactor. This shows the preferential flow of gas is more towards the lateral direction than in vertical direction. 3-17

18 Total gas Methane Oxygen Flow (scfm) Jan'04 Jul'04 Jan'05 Jul'05 Jan'06 Jul'06 Jan'07 Jul'07 Time Figure 3.14 Gas collected since January 2004 Landfill gas distribution of NRRL bioreactor Manholes 10% Side slope of the bioreactor 62% Top of the bioreactor 28% Figure 3.15 Pie-chart of the gas produced from various sections of the bioreactor Temperature of the waste in the landfill Temperature monitoring in bioreactor landfills is important to maintain ideal waste decomposition conditions as well as prevent subsurface fires. The aerobic decomposition of waste is highly exothermic compared to anaerobic decomposition. Hence, it is essential to monitor the temperature of aerobic bioreactor landfills. Type T thermocouple wires (Omega 3-18

19 Inc.) were installed to enable temperature monitoring at every vertical well and monitoring well clusters. All thermocouples were connected to a CR-10X data logger and a multiplexer (Campbell Scientific, Utah, U.S.) with a recording frequency of once every 20 minutes as shown in figure A more detailed description of the site, well installation and air injection system can be found in papers of Powell, et al. (2005) and Jain et al. (2005) in appendix D. Figure 3.16 Data logger station for collecting temperature and moisture data The Figure 3.17 shows the temperature data of a monitoring well collected from the data logger. This graph indicates the temperature profile of 20 and 40 feet deep wells that gradually rises due to air injection. Specific air injection experiments that address the effect of air addition on trace gas concentration, the radial extent of air addition and waste temperature dynamics associated with air addition are presented in thesis of Powell, J. (2005) in appendix C. Temperature ( o C) MN4 Y MN4 R Start of Recirculation Start/ Restart Air Injection Air Injection stopped Temperature ( o C) Days Figure Temperature rise due to air injection

20 3.5.4 Settlement of the waste Bioreactor landfills settle more during the initial years due to accelerated degradation and stabilization of the waste. Survey information was collected using a Z-model dual-frequency real-time kinematic (RTK) global positioning system (GPS) manufactured by Attach/Magellan Inc. (Santa Clara, California) as shown in Figure Both the vertical well clusters and the monitoring wells were surveyed periodically. For each vertical well cluster, readings were taken at the surface, and on top of the 20, 40 and 60 feet deep vertical wells. This gives an indication of the settlement at various depths of the landfills. Surveying was done periodically every 45 days. Figure 3.18 GPS system to determine the settlement of the landfill The settlement at the surface and at various depths of the landfill since leachate recirculated is shown in the Figure Based on settlement studies, it is observed that the bioreactor has settled over 8 feet. 3-20

21 0 2 Settlement (ft) Landfill Surface 60-ft Deep Wells 40-ft Deep Wells 20-ft Deep Wells Time (in days) Day 1 = 06/24/2002, Day 1953 = 10/09/2007 Figure 3.19Surveying instrument manufactured by Magellan Moisture content using TDR and MTG sensors The presence and movement of moisture in landfilled solid waste play a major role in the rate of landfill stabilization. The ability to track moisture content of the landfilled waste is beneficial to operators as they try to wet the waste uniformly. However, it is a challenge to understand the distribution of added moisture in a landfill because of the extreme heterogeneity of landfilled waste. A measure of in-situ moisture content would provide landfill operators very valuable information about the effectiveness of their leachate recirculation systems. Two types of in-situ moisture measuring sensors were installed at the New River Regional Landfill: TDR and MTG sensors. Both TDR and MTG sensors are connected to a CR-10X data logger (Campbell Scientific, Utah, U.S.) with a recording frequency of once every 20 minutes. A more detailed description of these sensors is present in volume 2 of this report. The figure 3.21 shows the resistance of the MTG moisture sensors at various depths of the landfill. The figure indicates a decrease in resistance due to wetting of these sensors due to leachate recirculation. A detailed description of these sensors can be found in the thesis of Jonnalagadda, S. (2004). 3-21

22 Resistance (KOHMS) Start of Leachate Recirculation L6E-Middle L6E-Lower L6E-Upper Days Figure 3.21Decrease in resistance in MTG sensors due to leachate recirculation 3.6 Conclusion For the full scale Florida Bioreactor demonstration project at NRRL, all the major input and output parameters were designed, measured, controlled and analyzed in the operation of the bioreactor landfill. They are summarized as follows. Major input parameters for the operation of a bioreactor The rate of leachate recirculation in this retrofitted bioreactor was calculated based on maximum leachate injection rate, aerobic degradation of waste, impact on leachate collection system and water balance within a landfill. The theoretical amount air required to run ¼ of the bioreactor under aerobic conditions was determined and used for sizing the blowers. More than 6.28 million gallons of leachate was recirculated using the vertical well system since December Major output parameters for the operation of a bioreactor The flow rate of leachate generated at the leachate collection system was measured using the Magnetic flow meter and the flow rates of leachate from individual manholes were measured using the weir box assembly. The quality of the leachate was measured at the lab using various analytical methods. The EPA landfill gas emissions model version 2.0 was used to calculate the landfill gas generation rate for sizing the blowers. GEM 2000 meter was used to measure the gas production and gas quality. Temperature of the waste in the landfill was measured using MTG sensor. Settlements of the landfill at various depths were measured using Ashtech GPS survey system. 3-22

23 Moisture content of the waste in the landfill was measured using MTG and TDR sensors. Appendix C. Theses and Dissertations Larson, J.A. (2007). Investigations at a bioreactor landfill to aid in the operation and design of horizontal injection liquids addition systems Master's Thesis, University of Florida, Gainesville, FL. Berge, N. (2006). In-Situ ammonia removal of leachate from bioreactor landfills. Ph.D. Dissertation. University of Central Florida, Orlando, FL. Mcknight Tobin (2005). Engineering properties and cone penetration testing of municipal solid waste to predict landfill settlement Master's Thesis, University Of Florida, Gainesville, FL. Kim, H. (2005). Comparative studies of aerobic and anaerobic landfills using simulatedlandfill lysimeters. Ph.D. Dissertation. University of Florida, Gainesville, FL. Powell, J. (2005). Trace gas quality, temperature control and extent of influence from air addition at a bioreactor landfill. Masters Thesis, University of Florida, Gainesville, FL. Jain, P. (2005). Moisture addition at bioreactor landfills using vertical wells: mathematical modeling and field application. Ph.D. Dissertation. University of Florida, Gainesville, FL. Jonnalagadda, S. (2004). Resistivity and time domain reflectrometry sensors for assessinging in-situ moisture content in a bioreactor landfill. Master's Thesis, University of Florida, Gainesville, FL. Sheridan, S. (2003). Modeling solid waste settlement as a function of mass loss. Master's Thesis, University of Florida, Gainesville, FL. Thomas, P.A. (2001). The testing and evaluation of a prototype sensor for the measurement of moisture content in bioreactor landfills. Masters Thesis, University of Central Florida, Orlando, FL. Gou, V. (2000). Non-methane organic compounds (NMOC) emitted from the decomposition of municipal solid waste (MSW) components. Master's Thesis, University of Florida, Gainesville, FL. Appendix D. Peer-Reviewed Journal Articles and Conference Proceedings Berge, N., Reinhart, D., Dietz, J., and Townsend, T. (2007) The impact of temperature and gas-phase oxygen on kinetics of in situ ammonia removal in bioreactor. Water Research, 41, Imhoff, P., Reinhart, D., Englund, M., Guerin, R., Gawande, N., Han, B., Jonnalagadda, S., Townsend, T., Yazdani, R. (2007) Review of state of the art methods for measuring water in landfills. Waste Management, 27(6), Gawande, N., Reinhart, D., Thomas, P., McCreanor. P., Townsend, T. (2003). Municipal solid waste in situ moisture content measurement using an electrical resistance sensor. Waste Management, 23,

24 Jain, P., Townsend, T., and Reinhart, R. (2005). Experiences from the operation of a fullscale bioreactor landfill in Florida. Solid Waste Association of North America s Wastecon 2005, Austin, TX, September 27-29, Jain, P., Farfour, W., Jonnalagadda, S., Townsend, T., and Reinhart, D. (2005). Performance evaluation of vertical wells for landfill leachate recirculation. Proceedings of Geo Frontier 2005, ASCE conference, January 24-26, 2005, Austin, TX. Reinhart, D., Townsend, T. and Bower, J. (2000). Florida landfill bioreactor project. Proceedings of the Waste Tech 2000, Landfill Technology Conference. Orlando, Florida, March 7, 10 pages 3-24