Soil-Stabilizing Potential of Using Food Industry Byproducts

Hydrous and quick lime is utilized in various types of food processing operations to remove impurities from agricultural products. During this process, the waste that is produced consists of precipitated calcium carbonate, organic debris, and trace amounts of soil and contaminants. When used in large-scale operations, the waste can exceed 100,000 tons of waste per year per site. This waste material is not compostable due to its chemical composition and is of too large of volume to be sent to landfills. Hence, the waste is typically stockpiled on land adjacent to food processing facilities, which is not an environmentally or economically sustainable solution. Finding an environmentally and economically sustainable solution to utilize this waste material has the potential to save capital on construction projects as well as significantly save in land investment by food processing facilities. The food-processing waste described above usually contains commercially available unspent lime products, which are viable for construction applications. Lime stabilization using relatively pure quick or hydrous lime has been successfully used to improve the strength and swelling properties of expansive clays. This paper studies the utilization of the above-mentioned waste in construction where the organic content by weight is consistently measured at lower than 5%. Using a series of geotechnical and environmental laboratory testing procedures, several engineering properties (e.g., swell potential, permeability, leachate potential) are measured to find the right series of tests and appropriate target blends of construction material and food processing waste. Preliminary testing points to reduced swelling potential and increased density when a sample of the food-processing waste is mixed with an expansive clay. Once procedures have been standardized, using these materials in construction applications may also produce a secondary revenue stream for certain food processing facilities.