Wastewater Contaminant Sorption and Dissolved Organic Matter Characterization

Irrigation using reclaimed wastewater can introduce organic contaminants and dissolved organic matter (DOM) to soils. Sorption of three common organic wastewater contaminants to five soils of diverse organic matter composition was studied both before and after the removal of soil carbohydrate and peptide components using acid hydrolysis. Results suggest that these polar components may block organic contaminants from accessing higher affinity sorption sites in soil organic matter. The sorptive fractionation of DOM by three mineral soils was studied to assess the terrestrial fate of this complex environmental matrix. Carboxyl- and aromatic-containing moieties appear to preferentially and reversibly sorb to mineral soils. Conversely, carbohydrate and peptide components of DOM preferentially remain in the aqueous phase while aliphatic moieties were selectively retained only by a soil with high surface area. This thesis illustrates that reclaimed wastewater should be applied to soils cautiously as it may degrade soil and groundwater quality.MAS