This study was aimed to assess the quality of groundwater in Chennai city. For the purpose of this study, Chennai city was divided into three zones based on the Legislative constituency into North, Central, and South Chennai. From these three zones, three locations were randomly selected (Zone 1, North Chennai included Ayyanavaram, Villivakkam, and Purasawalkam; Zone 2, Central Chennai included Triplicane, Mylapore, Nungambakkam; and Zone 3, South Chennai included Guindy, Velachery, and St. Thomas Mount) for assessment of water quality. One water sample for each location was assessed in this study. Hence, total of nine groundwater samples were collected from nine locations. Sample collection The groundwater sample from each location was collected from wells not less than 50 feet in order to avoid bacterial contamination. Further, these wells also had a cement concrete platform surrounding them as a higher elevation from the ground level which might reduce the possibility of contamination. The groundwater samples from each well were collected in a 2-litre clean polyethylene bottle from the nine locations. The samples were then analyzed for nine parameters such as pH, total dissolved solids (TDS), turbidity, total hardness, calcium, magnesium, sulphates, chlorides, and nitrates, Table 3: The physiochemical parameters and the water quality index in the three zones Parameters Zone 1 Zone 2 Zone 3 Loca 1 Loca 2 Loca 3 Location 1 Location 2 Location 3 Loca1 Loca2 Loca3 Ph 7.3 8.8 7.8 7.4 7.6 7.7 7.6 7.7 7.8 Mean 7.9 7.6 7.7 Turbidity (NTU) 1 1 10 1 1 5 3 5 5 Mean 4 2.3 4.3 TDS (mg/l) 1110 250 360 780 560 680 410 430 335 Mean 573.3 673.3 391.7 Hardness (mg/l) 210 124 112 450 284 320 116 116 96 Mean 148.7 351.3 109.3 Sulphate (mg/l) 164 22 50 48 45 40 64 50 56 Mean 78.7 44.3 56.7 Magnesium (mg/l 14 15 13 80 45 60 15 14 10 Mean 14 61.7 13 Nitrates (mg/l) 2.48 2.22 3.48 2.48 2.68 2.78 2.42 3.42 2.68 Mean 2.7 2.6 2.8 Chloride (mg/l) 300 38 88 170 64 120 108 120 80 Mean 142 118 102.7 Calcium (mg/l) 60 24 24 170 64 120 22 24 22 Mean 36 118 22.7 Water quality index level 19.21 46.12 43.71 43.20 32.34 48.36 26.29 31.75 31.75 Mean 36.3 41.3 29.9 Fluoride content 0.10 0.15 0.20 0.10 0.15 0.10 0.25 0.10 0.15 Mean 0.15 0.11 0.17
Posted on: Fri, 08 Nov 2013 09:21:47 +0000