Grantee Research Project Results
2002 Progress Report: Bioreactor Landfill Moisture Management
EPA Grant Number: R827933C022Subproject: this is subproject number 022 , established and managed by the Center Director under grant R825427
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Science and Policy Applications for Coastal Environments (CSPACE)
Center Director: D'Elia, Christopher F
Title: Bioreactor Landfill Moisture Management
Investigators: Schert, John D. , Reinhart, Debra R. , Townsend, Timothy
Institution: University of Florida , University of Central Florida
EPA Project Officer: Aja, Hayley
Project Period: July 1, 2000 through June 30, 2003
Project Period Covered by this Report: July 1, 2001 through June 30,2002
RFA: Urban Waste Management & Research Center (1998) RFA Text | Recipients Lists
Research Category: Targeted Research
Objective:
The objective of this subproject of the Urban Waste Management and Research Center (UWMRC) is to monitor and evaluate moisture movement and moisture balance in a bioreactor landfill operated under parallel aerobic and anaerobic conditions, something never before accomplished. Landfill leachate management can be one of the biggest challenges encountered by landfill managers. Bioreactor operation offers landfill managers the opportunity for leachate storage, treatment, and disposal. Although in situ moisture is a critical parameter to the success of bioreactor operations, it is one of the most difficult to measure accurately. This project provides an opportunity to evaluate available technology in a recirculating landfill environment.
Progress Summary:
The work accomplished for this project includes:
- Literature review of available in situ moisture instrumentation.
- Calibration of the moisture, temperature, and gas (MTG) sensor in the laboratory and part validation with field testing.
- Installation of MTG sensors in the bioreactor landfill facility at New River Regional Landfill (NRRL), Union County, Florida.
- In situ calibration and installation of time domain reflectometry (TDR) sensors in the bioreactor landfill.
- Installation of a data station for centralized data collection from bioreactor sensors and continuous acquisition of data from the field sensors.
The MTG sensor measures moisture content of solid waste indirectly by measuring the electrical resistance across the granular matrix of the sensor. The significant contribution of this research work in the area of resistance-based sensors for moisture measurement is the quantification of the effect of varying electrical conductivity of moisture and the effect of temperature on the resistance readings. When the two aforementioned factors are accounted for appropriately, it is possible to employ the resistance-based granular matrix sensor for moisture measurement in the landfill. Several TDR sensors have been installed at the NRRL bioreactor site to evaluate this technology.
Description of Yearly Work: Moisture, Temperature, and Gas (MTG) Sensor
Laboratory Calibration. The calibration curves for the MTG sensors reading moisture content of surrounding waste as a function of resistance measured across the granular matrix is shown in Figure 1. The sensor was sensitive enough to follow the trend of inverse relationship between moisture content and resistance values above waste moisture content of nearly 35 percent (w/w, wet basis). Waste moisture content below 35 percent resulted in dry conditions within the sensor and extremely high resistance values (greater than 30 kOhms) that were difficult to interpret.
Figure 1. Calibration Curve for MTG Sensors for Varying Moisture Conductivities (MC)
The effect of temperature on resistance was adopted from the U.S. Geological Survey (1998) equation that gives the effect of temperature on eC value as given by Equation 1. Equation 2 was obtained from Equation 1 by substituting the inverse of resistance for electrical conductivity.
(1)
where,
C25 = corrected conductivity value adjusted to 25ºC,
Cm = actual conductivity measured, and
tm = water temperature at time of Cm measurement in ºC.
(2)
where,
R1 = resistance at temperature t1, and
R2 = resistance at temperature t2
Field Testing. Three sensors were installed at the Orange County Landfill and monitored over time. Initial readings showed resistance readings of 50 to 80 kOhm, which suggested that the moisture levels were below MTG detection limit (~35%, w/w, wet basis). Laboratory analysis indicated a moisture content of 38.8 percent (w/w, wet basis), apparently below field capacity for this waste. After a few days, there was an increase in the moisture content to saturated conditions as a result of infiltration from precipitation. The sensors recorded the influx of precipitations over a short period of time, suggesting that they are capable of sensing rapid changes in waste moisture content. Waste samples were removed from an area near the sensors following the rain event. These samples clearly had extremely high moisture contents with leachate draining during waste sample removal. Sensors reported saturated conditions with resistance readings of 0.0357 and 0.0378 kOhms for the two different sensors. The gravimetric analysis of the nearby waste showed an MC of 59 percent (w/w, wet basis). Laboratory analysis may be low as a result of draining of leachate during sample extraction.
TDR Sensor. The data of moisture content collected from the TDR sensors installed in the bioreactor at the NRRL site in December 2002 are tabulated in Table 1. Probes 3 and 4 have shown consistent error in the generated waveform; this makes it difficult to interpret the MC values at these locations. At 10 other locations, the MC on volumetric basis was calculated from the calibration curve for TDR sensors.
When calculating MC from MTG sensors, an electrical conductivity (eC) value of 12.0 mS/cm was used, corresponding to the leachate eC value. In absence of a calibration curve for 12.0 mS/cm for MTG sensors, an extrapolation was performed on the values of 4.0 mS/cm and 8.0 mS/cm. Figure 2 shows the comparison of MTG sensor MC values on wet (w/w) basis and the values from TDR sensors on volumetric basis. The values from the MTG sensor reflect the expected values at those locations, whereas the TDR sensor values are scattered over a broad range. Although it is difficult to reach any conclusion in the absence of substantial data for comparison with changed field conditions, it is a known fact that the in situ values obtained by TDR method are difficult to adjust for any change in porosity of solid waste contained in the sensor. Also, every TDR sensor is packed with highly heterogeneous material that demands calibration of each sensor at varying MC levels and eC values.
Table 1. Moisture content data from TDR sensors
Probe / Location |
Volumetric Water Content |
Remarks |
---|---|---|
1(H6-U) |
20.8 |
|
2 (I7-U) |
19.7 |
|
3 (H6-L) |
Error |
Consistent Error |
4 (H6-M) |
Error |
Consistent Error |
5 (I5-U) |
16.3 |
|
6 (I6-L) |
13.9 |
|
7 (I6-M) |
15 |
|
8 (I6-U) |
20.1 |
|
9 (G7-U) |
35.1 |
|
10 (I7-M) |
31.3 |
|
11 (I5-M) |
32.5 |
|
12 (G7-M) |
22.2 |
Figure 2. Comparison of MTG and TDR Sensor Moisture Content Values
Future Activities:
Leachate recirculation in the bioreactor at NRRL was started in June 2003. The movement of moisture and its effect on the moisture content of solid waste will be monitored in the future. The performance of MTG sensors in comparison with TDR sensors will be evaluated and, eventually, further validated with samples of solid waste extracted from the bioreactor. The electrical conductivity values for leachate samples collected from injection wells at the NRRL site showed values as high as 24 mS/cm. Therefore, the laboratory calibration of MTG sensors will be continued for a few data points at high eC values of 12.0 and 24.0 mS/cm.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other subproject views: | All 6 publications | 1 publications in selected types | All 1 journal articles |
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Other center views: | All 55 publications | 13 publications in selected types | All 7 journal articles |
Type | Citation | ||
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|
Gawande NA, Reinhart DR, Thomas PA, McCreanor PT, Townsend TG. Municipal solid waste in situ moisture content measurement using an electrical resistance sensor. Waste Management 2003;23(7):667-674. |
R827933C022 (2002) |
Exit Exit |
Supplemental Keywords:
solid waste, landfill, moisture measurement, moisture sensors,, Scientific Discipline, Waste, Environmental Chemistry, Municipal, Civil Engineering, Environmental Engineering, landfill design, leachate recirculation landfills, evaluation of leaching, landfill operation, moisture content, municipal waste, municipal solid waste landfills, waste management, waste disposal, bioreactorProgress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R825427 Center for Science and Policy Applications for Coastal Environments (CSPACE) Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825427C001 Comprehensive Evaluation of The Dual Trickling Filter Solids Contact Process
R825427C002 Issues Involving the Vertical Expansion of Landfills
R825427C003 Deep Foundations on Brownfields Sites
R825427C004 Ambient Particulate Concentration Model for Traffic Intersections
R825427C005 Effectiveness of Rehabilitation Approaches for I/I Reduction
R825427C006 Urban Solid Waste Management Videos
R825427C007 UWMRC Community Outreach Multimedia Exhibit
R825427C008 Including New Technology into the Investigation of Inappropriate Pollutant Entries into Storm Drainage Systems - A User's Guide
R825427C009 Investigation of Hydraulic Characteristics and Alternative Model Development of Subsurface Flow Constructed Wetlands
R825427C010 Beneficial Use Of Urban Runoff For Wetland Enhancement
R825427C011 Urban Storm and Waste Water Outfall Modeling
R827933C001 Development of a Model Sediment Control Ordinance for Louisiana
R827933C002 Inappropriate Discharge to Stormwater Drainage (Demonstration Project)
R827933C003 Alternate Liner Evaluation Model
R827933C004 LA DNR - DEQ - Regional Waste Management
R827933C005 Landfill Design Specifications
R827933C006 Geosynthetic Clay Liners as Alternative Barrier Systems
R827933C007 Used Tire Monofill
R827933C008 A Comparison of Upflow Anaerobic Sludge Bed (USAB) and the Anaerobic Biofilm Fluidized Bed Reactor (ABFBR) for the Treatment of Municipal Wastewater
R827933C009 Integrated Environmental Management Plan for Shipbuilding Facilities
R827933C010 Nicaragua
R827933C011 Louisiana Environmental Education and Resource Program
R827933C012 Costa Rica - Costa Rican Initiative
R827933C013 Evaluation of Cr(VI) Exposure Assessment in the Shipbuilding Industry
R827933C014 LaTAP, Louisiana Technical Assistance Program: Pollution Prevention for Small Businesses
R827933C015 Louisiana Environmental Leadership Pollution Prevention Program
R827933C016 Inexpensive Non-Toxic Pigment Substitute for Chromium in Primer for Aluminum Sibstrate
R827933C017 China - Innovative Waste Composting Plan for the City of Benxi, People's Rupublic of China
R827933C018 Institutional Control in Brownfields Redevelopment: A Methodology for Community Participation and Sustainability
R827933C019 Physico-Chemical Assessment for Treatment of Storm Water From Impervious Urban Watersheds Typical of the Gulf Coast
R827933C020 Influence of Cyclic Interfacial Redox Conditions on the Structure and Integrity of Clay Liners for Landfills Subject to Variable High Groundwater Conditions in the Gulf Coast Region
R827933C021 Characterizing Moisture Content Within Landfills
R827933C022 Bioreactor Landfill Moisture Management
R827933C023 Urban Water Issues: A Video Series
R827933C024 Water Quality Modeling in Urban Storm Water Systems
R827933C025 The Development of a Web Based Instruction (WBI) Program for the UWMRC User's Guide (Investigation of Inappropriate Pollutant Entries Into Storm Drainage Systems)
R827933C027 Legal Issues of SSO's: Private Property Sources and Non-NPDES Entities
R827933C028 Brownfields Issues: A Video Series
R827933C029 Facultative Landfill Bioreactors (FLB): A Pilot-Scale Study of Waste Stabilization, Landfill Gas Emissions, Leachate Treatment, and Landfill Geotechnical Properties
R827933C030 Advances in Municipal Wastewater Treatment
R827933C031 Design Criteria for Sanitary Sewer System Rehabilitation
R827933C032 Deep Foundations in Brownfield Areas: Continuing Investigation
R827933C033 Gradation-Based Transport, Kinetics, Coagulation, and Flocculation of Urban Watershed Rainfall-Runoff Particulate Matter
R827933C034 Leaching and Stabilization of Solid-Phase Residuals Separated by Storm Water BMPs Capturing Urban Runoff Impacted by Transportation Activities and Infrastructure
R827933C035 Fate of Pathogens in Storm Water Runoff
R87933C020 Influence of Cyclic Interfacial Redox Conditions on the Structure and Integrity of Clay Liners for Landfills Subject to Variable High Groundwater Conditions in the Gulf Coast Region
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
1 journal articles for this subproject
Main Center: R825427
55 publications for this center
7 journal articles for this center