MINERAL CHARACTERISTICS OF FOUNDRY SAND: IMPACTS ON SOIL HYDRAULIC CONDUCTIVITY, EROSION AND PLANT GROWTH
Project Number: 1265-12000-035-05
Specific Cooperative Agreement
Start Date: Mar 15, 2005
End Date: Mar 14, 2010
This cooperative research proposal will investigate three key issues that are fundamental to the use of foundry sands (FSs) in agricultural and urban soil applications. The first issue relates to the physical and mineralogical properties of the FS particle size separates. The second and third issues relate to erosion characteristics of land-applied FS and FS blended products and their ability to support plant growth, respectively. Specific project objectives will be to:
1. Determine the mineralogy of spent FS particle size fractions and the swelling potential of these separates at differing temperatures.
2. Determine the erosion characteristics of land applied FS and FS blended products.
3. Evaluate the suitability of land applied FS and FS blended products for plant growth.
Laboratory, greenhouse, and field experiments will be used to achieve the above objectives. The project will utilize spent FSs obtained from ferrous and aluminum foundries in Indiana. During year one of the project, we will determine the mineralogy of spent FS particle size fractions (by standard x-ray diffraction (XRD) methods and optical analysis using petrographic microscopy) and the swelling potential of these separates at differing temperatures. Unspent FS clays will be incrementally heated in a muffle furnace to temperatures similar to foundry processing procedures. X-ray diffraction patterns of spent FS will be compared to the x-ray diffraction patterns of the incrementally heated particle size separates in order to determine the predominant minerals present in the bulk FS. Hydraulic conductivity will be measured on the particle size separates in the laboratory using the falling head soil core method. Based on the information provided in the study above, FSs will be selected for use in subsequent erosion and plant growth studies as described below:
Erosion Study: a programmable variable'intensity oscillating nozzle rainfall simulator will be used to determine the runoff characteristics of land application of FSs and FS blends under varying slope and vegetative conditions that simulate various states of urban development. Differing treatments will be applied as a topdressing to soil as well as incorporated into the soil. This research will be conducted at the USDA-National Soil Erosion Research Laboratory located on the Purdue University campus.
Plant Growth Study: FS and blended products will be evaluated for their impact to plant growth. Physical and chemical properties (hydraulic conductivity, particle size distribution, cation exchange capacity, pH, electrical conductivity, and plant nutrients) will be determined on FS and FS blended with soil from the argillic horizon of common northern Indiana subsoils to simulate the incorporation of FS in urban lawns immediately following house development. Plant growth in the FS and blended FS:Soil will be analyzed in the greenhouse. Field plots will be established at the Throckmorton Purdue Agricultural Center with these mixes at the Throckmorton - Purdue Agricultural Center, located 15 miles south of the Purdue University West Lafayette campus.