Source: ENERGY RESOURCE INSTITUTE submitted to NRP
TREATMENT OF METHYL BROMIDE OFF-GASES (PHASE II)
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
SMALL BUSINESS GRANT
Reporting Frequency
Annual
Accession No.
0193086
Grant No.
2002-33610-12428
Cumulative Award Amt.
(N/A)
Proposal No.
2002-03039
Multistate No.
(N/A)
Project Start Date
Sep 1, 2002
Project End Date
Apr 30, 2005
Grant Year
2002
Program Code
[8.4]- (N/A)
Recipient Organization
ENERGY RESOURCE INSTITUTE
1612 KINGSPORT DRIVE
RIVERSIDE,CA 92506
Performing Department
(N/A)
Non Technical Summary
Methyl bromide is an effective fumigant, however, the U.S. EPA will soon prohibit the use of methyl bromide because it has been found to be a significant ozone depleting substance. Although a number of significant research efforts have been conducted to find alternatives for soil and post-harvest fumigation, so far these are either more costly or not as effective as methyl bromide. Another approach to mitigate the effects of methyl bromide would be to capture and to treat the methyl bromide contaminated air. In Phase I, we successfully demonstrated effective biological treatment of methyl bromide off-gas in lab-scale biotrickling filters. Thus, the purpose of Phase II is to further develop and optimize biotrickling filtration of fumigation exhausts and to demonstrate the technology in the field.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1330410202030%
1334010100035%
1335220100035%
Knowledge Area
133 - Pollution Prevention and Mitigation;

Subject Of Investigation
4010 - Bacteria; 0410 - Air; 5220 - Pesticides;

Field Of Science
2020 - Engineering; 1000 - Biochemistry and biophysics;
Goals / Objectives
The overall objective of Phase II is to further develop and optimize biotrickling filtration of methyl bromide and to demonstrate the technology in the field. At the end of Phase II, the Energy Resource Institute should be in the unique position of being able to commercialize biotrickling filter systems for the safe and reliable treatment of methyl bromide air streams from fumigations. Supporting objectives to be achieved during Phase II are to: 1. Complete the characterization of the pure, methyl bromide degrading microorganisms obtained in Phase I and select the best strains to be used in biotrickling filters. 2. Design, construct and test a new load-dampening system (laboratory-scale). 3. Design and construct a mobile pilot-scale biotrickling filter (including the load dampening system) for field demonstrations of effective methyl bromide treatment. 4. Demonstrate sustained and effective methyl bromide treatment at least at one quarantine fumigation facility, and at least one field fumigation. For the latter, this will include demonstration of a new collection system (two-layer tarp) to improve capture of methyl bromide from soil fumigations. 5. Develop a mathematical model of the load dampening-biotrickling filtration system to be used for system scale-up, system sizing, and for cost evaluation. 6. Fully evaluate the costs of the proposed technique, apply for patents and develop market opportunities.
Project Methods
Methyl bromide is an effective fumigant that has been in use since the 1930s. However, the U.S. EPA will soon prohibit the use of methyl bromide because it has been found to be a significant ozone depleting substance. Although a number of significant research efforts have been conducted to find alternatives for soil and post-harvest fumigation, so far these are either more costly or not as effective as methyl bromide. Another approach to mitigate the effects of methyl bromide would be to capture and to treat the methyl bromide contaminated air to minimize release to the atmosphere. In Phase I, we successfully demonstrated effective biological treatment of methyl bromide off-gas in lab-scale biotrickling filters for air pollution control and concluded that the proposed technology has a great potential. Thus, the overall objectives of the proposed Phase II is to further develop and optimize biotrickling filtration of fumigation exhausts and to demonstrate the technology in the field. The supporting objectives of Phase II are: - Complete the characterization of our methyl bromide degrading microorganisms. - Design, construct and test a new load-dampening system (lab-scale). - Design and construct a mobile pilot-scale biotrickling filter and demonstrate methyl bromide treatment at least at one quarantine fumigation facility, and at least one field fumigation. - Develop a mathematical model to be used for system scale-up, system sizing, and for cost evaluation. - Determine treatment costs and develop market opportunities. An interconnected research approach was developed.

Progress 09/01/02 to 04/30/05

Outputs
The overall objective this SBIR award was to develop and demonstrate a biological method called biotrickling filtration for the treatment of methyl bromide from fumigation exhausts. Once fully developed, the proposed method could be deployed to treat methyl bromide from the exhaust of fumigations, hence preventing its escape to the atmosphere. More specifically, the objective of Phase II was to further develop and optimize biotrickling filtration of methyl bromide that had been demonstrated in the laboratory during Phase I, and to design a mobile demonstration biotrickling filter, build it, and demonstrate the technology in the field. To achieve these goals, the following tasks were identified for Phase II: 1. To complete the characterization of the pure methyl bromide degrading microorganisms. 2. To design, construct and test a load-dampening system. 3. To design and construct a mobile pilot-scale biotrickling filter for field demonstration. 4. To develop a mathematical model of the load dampening system. 5. To demonstrate methyl bromide treatment in the field. 6. To fully evaluate the costs of the proposed technique, apply for patents and develop market opportunities. Tasks 1-4 were successfully completed while problems experienced with the pilot treatment system in the field prevented us to successfully complete Tasks 5-6. One U.S Patent is pending. The methyl bromide degrading organisms used in the biotrickling filter were isolated and identified and a procedure to grow them in the lab was developed. Significant efforts were directed towards conditioning of fumigation exhausts, as this was a very crucial element for success. Fumigation exhausts are subject to large fluctuations because of the nature of fumigation operations. Highly fluctuating loads of methyl bromide could be very effectively dampened using a passive adsorber-desorber packed with granular activated carbon. The conditioning of the gas resulted in a quasi constant concentration which was much more amenable to treatment. The load dampening system was also modeled using a simple linear driving force-mass transfer model and the model could be used for load dampening system sizing. Next, a mobile pilot-scale biotrickling filter which included the load dampening system was designed and constructed so that a field demonstrations of effective methyl bromide treatment could be conducted. Field treatment of methyl bromide was conducted over close to 8 months at a fumigation facility located near the Long Beach-L.A. Port. The field demonstration ran into severe technical problems which escalated to the point where the system was rendered inoperable, and the demonstration had to be halted. Unfortunately, to date, the system has not been refurbish for lack of men-power and resources to do it adequately, and effective and sustained demonstration of methyl bromide treatment in the field has not yet been accomplished. Even so, there is genuine interest in finding ways to capture and to treat methyl bromide so as to avoid releases of methyl bromide in the environment. Thus the proposed methyl bromide capture and treatment system appears to fill a definitive need.

Impacts
Once fully developed, the proposed method could be deployed to treat methyl bromide from the exhaust of fumigations, hence preventing its escape to the atmosphere. This would allow to continue the use of methyl bromide in key applications without any environmental impact.

Publications

  • No publications reported this period