Abstract
Abstract
This study was undertaken to assess the Physico- chemical characteristics of waste water of Nalapani Rao, Dehradun city, before it merges with the Rispana
River near MDDA colony, Dalanwala. The variations in the parameters were observed by monitoring the drain water at four locations from July to December on monthly basis. The observed DO values were very low that varied from 0.98 to 1.70 mg/L, which itself reflecting the poor quality of the drain. The observed range of other parameters were: pH (7.56–7.81), TDS (1142- 1372 mg/L), EC (1598 - 1892 μS/cm), TH (473 –536 mg/L), DO (0.98 – 1.70 mg/L), BOD (96–201mg/L), COD (218– 431 mg/L), nitrate (16.6 – 42.8 mg/L), phosphate (0.11- 0.21 mg/L), and chloride (21.2- 57.4). Except, pH, nitrate and chloride the observed levels of all the parameters at all the locations were much higher than standard values. Further, during high flow months because of strong dilution effect due to high flux of rain water, the observed values of TDS, BOD, COD, chloride were improved and recorded comparatively lower values, than during October to December. On computing Pearson’s correlation analysis, the highly positive correlations between EC and TDS (r = +0.9348), COD and DO (r =
+ 0.9997), nitrate and BOD (+ 0.7578) and COD (+ 0.7687) and phosphate and nitrate (+ 0.9267), COD (+ 0.8892) and BOD (+ 0.8825) were observed.
Similarly, a highly negative correlations were observed between DO and BOD (-0.9572), COD (-0.9584). Upon application of one way ANOVA at p<0.05 level,
significant differences among the season wise and location wise experimental values of various parameters were also computed.