| Aquatic organic matter (AOM) is derived from natural and/or anthropogenic sources and is slowly formed and transformed through biotic and abiotic geochemical pathways. The processing of organic material along these pathways can occur independently and simultaneously to produce a complex residual mixture of macromolecular and polymorphic condensation products that vary structurally and quantitatively in time and space.; Our ability to characterize fully AOM is limited by our inability to analyze a complex mixture of non-volatile macromolecular materials comprehensively. In this research, we have demonstrated that pyrolysis-GC/MS is a useful tool for the characterization of AOM. Specifically, we have developed a simple means of external and internal standardizations, reduced the large amount of data produced by pyrolysis-GC/MS to what was significant, and quantified those significant markers by relating them to other chemical and biological data.; We applied the pyrolysis-GC/MS protocol to address questions concerning the fate of AOM in water reuse. We found that: (1) effluent-derived AOM (EfOM) differed from naturally-derived AOM, (2) EfOM persisted in natural waters, (3) EfOM had higher disinfection byproduct (DBP) formation potential and shifted to brominated-products, and (4) chemical markers that were responsible for DBP formation consisted of aromatic and aliphatic structures, some of which possessed organic nitrogen and halogen signatures.; The use of pyrolysis-GC/MS was also demonstrated in the wetlands study. We found: (1) chemical markers that were associated with urban development in the Des Plaines River watershed, (2) chemical makers of seasonal change, (3) wetland AOM to be controlled by feed water AOM, (4) organic carbon quality to influence denitrification potential, (5) chemical markers of biodegradability, and (6) thick mats of periphyton grown on artificial benthic mat supported very high rates of denitrification, which was hypothesized to be related to highly assimilable algal-derived carbon source.; Overall, we improved upon an analytical method that can be used to monitor AOM, allowing the discrimination among samples derived from different sources and influenced by various effects. In addition, this study established the relationship between certain structural features in AOM and their behavior or performance under a defined set of environmental condition. |
