Tuesday, November 6, 2007
212-4
Oxygen Demand, Carbon and Nitrogen Relationships in Effluent Surface Waters.
Theophilus Udeigwe, School of Plant Environmental and Soil Sciences, Louisiana State University, 104 M.B. Sturgis Hall, Baton Rouge, LA 70803, Jim Wang, School of Plant,Environmental&Soil Sciences, Louisiana State University, 313 M.B. Sturgis Hall, Louisiana State University, Baton Rouge, LA 70803, Lewis Gaston, 104 Sturgis Hall, Louisiana State University, Louisiana State University, School of Plant, Environmental and Soil Sciences, Baton Rouge, LA 70803-2110, and Sonny Viator, Iberia Research Station, Louisiana State University AgCenter, 603 Bridge Road, Jeanerette, LA 70544.
The organic biodegradable carbon carried by surface runoff from fields is one of the major components that define water quality. This is traditionally measured using biochemical oxygen demand (BOD) test. However, there are many limitations to BOD measurements, thus the results are variable and not easily reproducible. Extensive literature search revealed that little information is available on relationships relating the BOD of surface water samples to their carbon content along with nutrients, particularly nitrogen, since this appears to be an integral component in oxygen demand evaluation. The chief objective of this study is to evaluate the oxygen demand, carbon and nitrogen relationships among water samples containing different organic substrates, and thus establish relationships relating BOD measurements to these water quality parameters. For this study, potential sources of carbon and nitrogen which are normally applied to agricultural fields and often washed away during runoff will be employed to generate water samples. The selected materials include sewage sludge, chicken litter, cattle manure, green manure, and wetland materials. Specified amount(s) of each selected material will be used to obtain water samples with a range of organic carbon and nitrogen levels typical of those obtained in agricultural runoff water samples. The obtained water samples will be evaluated for BOD, total organic carbon, dissolved organic carbon, and nitrogen, and the relationships among these measured parameters will be evaluated.