Karuna Ekka, Sanjaya Kumar Pattanayak, Narad Rajesh, Suman Prakash Horrow, Rinki Meher, Mamata Chhuria and Pratik Kumar Dash
Abstract
The rapid pace of urbanisation and increasing population pressure has brought in a host of environmental problems in Sambalpur city. The waste-water flowing in the nalas in the city are drained into Mahanadi River. A study was carried out during Monsoon and Winter seasons during which water from the sewage nala Branch-1(B1), Branch-2(B2), Branch-3 (B3), two ponds (P1 and P2) and one site on Mahanadi River (M1) were collected. The samples were analyzed for pH, EC, Turbidity, Total Solid (TS), Total Hardness (TH), Total Alkalinity (TA), Sulphate, Chloride, free CO2, Sodium, Potassium, Nitrate, Phosphate, COD, DO and BOD. The critical observations with respect to some important parameters are discussed. The SO4 concentration in water during Monsoon was high (90.24 -178.56 mg/l) compared to that of winter (34.56-119.04 mg/l) for all the stations. The Pond water sulphate (145.92-178.56 mg/L) concentration was comparable to that of Waste-water (90.24-157.44 mg/l) and of Mahanadi River water (113.36 mg/l) during Monsoon. The Cl values of pond water are comparable with that of the downstream portion of the nala (97.98-83.78 mg/l). The water of the pond P-1 showed high Na values (78.79-80 mg/l) in both the seasons while that of pond P2 (27.32-31.25 mg/l) is comparable with the downstream stretch B3 of the nala (20.64-31.06 mg/l). The Na concentration in Mahanadi River water was low (4.41-8.41 mg/l). K values in all the stations varied between (0.04 - 35.88 mg/l) except the high value (132-367.3 mg/l) reported for B2-1 site. The NO3 of pond water (60- 215 mg/l) are comparable with that of the sewage nala (40-370 mg/l). The NO3 of Mahanadi River water is low compared to that of sewage nala water. The PO4 concentration in sewage nala water (2.5-55 mg/l) is comparable to that of pond water (13-47 mg/l) and Mahanadi Riverwater (39-48 mg/l). The winter COD values of pond water (180-260 mg/l) and river water (180-184 mg/l) are comparable with that of sewage nala water (144-540 mg/l). The DO concentration of water is low (0.72-4.96 mg/l) in wastewater nalas and ponds and BOD is high (8-257 mg/l). The above observations suggest that the quality of ground water of the region is affected because the reservoir is recharged by the polluted sewage nala water. Decrease in the values of different parameters in the Mahanadi River water compared to that in the sewage nala water could be attributed to dilution effects. The study points at a serious ecological concern for the aquatic ecosystem of the region and demands for appropriate management plan for waste-water generated from the city.