Buffering Capacity of Biosolids from St. Mary's Paper
Mark A. Jarski
School of Natural Science Lake Superior State University Sault Ste. Marie, MI 49783
ABSTRACT. Biosolids are a nutrient-rich organic product of wastewater treatment. Biosolids can be a beneficial resource containing essential plant nutrients and organic matter. They can be used for land reclamation and to enhance vegetative growth. In this study, I wanted to determine the biosolids buffering capabilities. Buffering capacity is the resistance to change in pH. Samples were collected from St. Mary's Paper in Sault Ste. Marie, Ontario. The samples were tested for buffering capacity with additions of distilled water (pH 5.2), alkaline water (pH 8.3), and lime (pH 9.3) and distilled water (pH 5.2). After three weeks the pH of the samples were measured to determine if there was a change in pH. The distilled water addition showed some increase and decrease in pH. The alkaline water addition samples showed a wide variability of pH with no evidence of a direct increase or stability in pH throughout the samples. The addition of lime and distilled water did not show a clear trend in pH increase or stability. My controls also showed a wide variability in pH, though no water was added to the samples. These changes could be attributed to the complexity of the biosolids makeup and the various chemical reactions taking place within the samples. It was determined that in some cases the biosolids showed some resistance to change in pH. However, the pH was more often quite scattered showing no distinct trend in buffering capabilities.