Assessment of Pollution Level of Habbaniya Lake, Iraq, Using Organic Pollution indicators

Abstract

In this study, we used some organic pollution indicators (DO, BOD and COD) to estimate the pollution level of Habbaniya Lake, Iraq. The surface water samples were collected from six stations. The sampling was bimonthly. The parameters, DO, pH, and T were measured in field using portable meters, while Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were determined by standard methods, respectively. Variation of DO with depth, temporal and spatial variation of DO, BOD and COD were investigated. The DO level ranged from 6. 72 mg l-1 to 10. 57 mgl-1 with a mean value of 8. 9 mgl- . The mean value of DO level was above the WHO permissible limit for the protection of fisheries and aquatic life and for domestic water supply. Results show variation of DO with vertically. The BOD level varied from 2. 86 to 11. 16 mgl-1 with a mean value of 7. 53 mgl-1 . Mean value of BOD is within the WHO and USEPA permissible limits. COD levels ranged between 26. 83 and 40. 33 mgl-1 with a mean value of 33. 47 mg l -1 . The mean value of COD did not exceed the WHO limit. Analysis of variance (ANOVA) showed that there is significant difference between the sampling periods for values of DO and BOD, insignificant difference for COD values and insignificant difference between the sampling stations. The results of organic pollution indicators show that Habbaniya Lake is unpolluted to less pollution in the organic matter during the sampling period and could support aquatic life and use as domestic water supply.