Modeling Biochemical Oxygen Demand Through the Middle and Lower Savannah River¹

Abstract

In order to improve modeling accuracy and general understanding of lotic biochemical oxygen demand (BOD), this study characterized river metabolism with the current Georgia Environmental Protection Division method for the middle and lower Savannah River basin (MLSRB) and several alternative methods developed with 120-day, long-term biochemical oxygen demand (LTBOD) data from the MLSRB. The data were a subset of a larger two-year LTBOD study to characterize and understand BOD in the MLSRB, located approximately between Augusta, Georgia, and Savannah, Georgia, along the border of Georgia and South Carolina. The LTBOD data included total oxygen loss and nitrogen speciation for separately quantifying nitrification. Results support the following insights and opportunities for modeling methods: (1) it is important to modeling accuracy that residuals be checked for even dispersion to avoid areas of over-and underprediction; (2) modeling with bounded, yet unfixed, rates is a sufficiently simple alternative to fixed-rate modeling that can eliminate the need for manual adjustments and provide additional system understanding to inform regulation; (3) if fixed rates modeling is desired, model quality for this system might be improved through revising the current low rate (along with the associated f-ratio updates) from 0.02 ⁄ day rate to 0.006 ⁄ day and potentially adding a new rate at 1.0 ⁄ day in some cases; and (4) the current 57 ⁄ 43 ratio of slow ⁄ fast BOD is reasonable based on the 52 ⁄ 45 ⁄ 3 slow ⁄ fast ⁄ faster BOD proportions of this study.(KEY TERMS: environmental impacts; environmental regulations; microbiological processes; rivers ⁄ streams; simulation; total maximum daily load; transport and fate.) Rosenquist, Shawn E., Jason W. Moak, and Oscar P. Flite, 2012. Modeling Biochemical Oxygen Demand Through the Middle and Lower Savannah River.

Short term assessment of nutrients and physicochemical parameters considering different depths in a hypersaline lagoon – Araruama Lagoon –RJ

“…The high values of DO in the water column of Araruama Lagoon are prone to readily supply the BOD5 from domestic effluent discharges (ROSENQUIST et al, 2013). These two parameters were relatively homogenous in the water column all over the lagoon and no significant spatial or vertical stratification was identified.…”