Abstract
Dissolved oxygen and biochemical oxygen demand (BOD) have been assessed at different sites of the two lakes, Bellal and Pandu of Bodhan. In the Bellal lake dissolved oxygen varies from 4.40 to 13.70 mg/L. In the month of February the dissolved oxygen was much higher than the normal range, although most of the samples showed dissolved oxygen within normal range. The maximum value of BOD in Bellal lake was recorded at 40.20 mg/L. Dissolved oxygen in Pandu was found to be low in most of the water samples. Oxygen deficient was prominent, which has detrimental effect on other physicochemical factors and population density. The average value of biochemical oxygen demand in Pandu lake was found to be 60.32 mg/L which is comparatively more than that Bellal lake. The depletion of dissolved oxygen and higher values of biochemical oxygen demand were due to domestic sewage and industrial outlet into the Pandu lake. The depletion of dissolved oxygen in Bellal Lake might be due to agricultural runoff. The Pandu lake can be considered transforming from mesotrophic to eutrophic lake. However, the Bellal lake is oligotrophic in its current situation. Contrarily Bellal Lake is least polluted as it has high dissolved oxygen and the low biochemical oxygen demand.