Design of sediment oxygen demand (SOD) 'in-situ' measuring chamber and its application in several rivers

Abstract

Sediment oxygen demand is defined as the rate of dissolved oxygen removal from the water column by the decomposition of organic materials in the bottom sediments. Accurate SOD rates are important, as they will allow for more precise permits specifications and therefore the degree or level of wastewater treatment needed. The "in situ" SOD chamber designed for the study was adapted from an earlier design by the USEPA (Hatcher, 1986). Two sets of chambers of differing sizes were fabricated and used to measure the SOD levels in several rivers and a small lake. These measurements could be used for the calibration and validation water quality models. Another applied usage of the SOD chamber was for the management of aquaculture ponds. The knowledge of the SOD levels at the bottom of the aquaculture ponds will allow for a more systematic pond-cleaning schedule.