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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Research Project #429042

Research Project: Formosa Mine Project: Amending Metals Contaminated Mine Soil with Biochar and Other Amendments to Facilitate Soil Remediation

Location: Coastal Plain Soil, Water and Plant Conservation Research

Project Number: 6082-12630-001-03-I
Project Type: Interagency Reimbursable Agreement

Start Date: Aug 1, 2015
End Date: Jul 31, 2020

1. To produce a comprehensive set of designer biochars by pyrolysis of a variety of local feedstocks that have a variety of chemical and physical characteristics. 2. To improve soil health of mine spoils using the designer biochars that will allow for establishment of native plant cover to stabilize the landscape.

As a synthesis, funds will be used for a cross-location project with several ARS scientists participating in an Interagency Agreement with the USEPA. The project will use funds to develop designer biochars to restore the soil health of spoils at the Formosan Mine spoils site in Riddel, Oregon. The ARS scientists will specifically use the funds to select feedstocks, pyrolyze the feedstocks to manufacture designer biochars, characterize the initial soil health, conduct preliminary lab and greenhouse with native plants on treated mine spoils, and establish field-scale test plots. Our individual approach will vary with each scientists, but we will: 1. Formosa mine spoil soil collection and characterization for on-site assessment for subsequent plot establishment. 2. Spoil extraction using simulated rainwater or EPA method 1312: Characterization of the extractant for pH, salt content, dissolved organic carbon, and metals. 3. Biochar production from local feedstocks include douglas-fir wood chips, Oregon White Oak wood chips, bettle-killed lodgepole pine chips, Kentucky bluegrass, tall fescue, Giant Reed, Blue wild rye, Miscanthus, sorghum, anaerobically, digested fiber, spent brewers yeast, and hazlenut shells. All of these feedstocks or blend will be pyrolyzed at 300 to 700 Celsius degrees. 4. Biochars will be characterized for their ability to improve mine spoil chemical, microbiological, and hydraulic properties that are important for establishing plant growth covers while reducing heavy metal migration. 5. Biochars will be tested for their suitability to meet the above stated objectives in a series of lab and greenhouse experiments by selecting native plant species ( e.g., California brome, Tufted hairgrass) on spoils treated with 1 to 4% biochars. Plants will be grown in pvc tubes and during experiment plant biomass will be measured. Leachates will be collected and will be analyzed for heavy metals. Spoils will be assayed for plant available metals and for total metals using EPA method 3051. We will also examine the mine spoils for modifications in microbial properties. Treated mine soils will also be examined for their ability to retain moisture and for plant available water contents. 6. Results from the lab/greenhouse experiments will be synthesized to determine the most suitable biochars to be produced in tonnage quantities for field scale applications. The plots will be set up in statistically approved setup. After biochar application, native plants will be planted and soil analyzed (see item #5). 7. Results from items 6 and 7 will be used to set up longer term management strategies for maintaining the sites soil health and plant cover integrity.