A study on the effect of BRPL effluents on growth and yield of certain economic plants with particular reference to rice oryza sativa

Abstract

This study embodies the results of quantitative estimations done on the effluents discharged by the BRPL to the neighbouring rice fields located at various distances from the source of effluent and their effect on growth and yield of rice (Oryza sativa L.var. Bora) plant. The results obtained during the experiments are discussed in the light of available literature in the chapter on Results and Discussion. The water and soil samples of rice fields of BRPL effluent affected area (polluted) and non-affected area (control) were periodically collected i.e., at an interval of 30 days and analysed to assess the pollution status emanating from effluent contamination and its impact on different physico-chemical properties of soil. BRPL effluent possessed intensive oil pollution due to phenols, oil and grease and high contents of nitrate nitrogen. Irrigation with such water quality rendered detrimental effect on soil quality. During the experiments quantitative estimation of temperature, colour, odour, pH, turbidity, oil and grease content, conductivity, total suspended solids ( TSS ), total dissolved soilds (TDS), total alkalinity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), total hardness (TH), presence of Ca++, Mg++, phenol and nitrate nitrogen were made on water samples. The result showed that though the colour, odour and pH of the water samples collected from the polluted areas were within the acceptable range, the value of turbidity, TSS, TDS, BOD and COD were much higher than the acceptable range. Turbidity, TSS, TDS, BOD and COD of water samples ranged between 28.85 - 40.04 NTU, 9.85 - 13.88, 41.75-55.12, 8.35-10.24 and 22.23-24.01 mg/I respectively in polluted areas. Temperature, electrical conductivity, total alkalinity, total hardness, nitrate nitrogen content in water samples of polluted areas were higher than those of control area, which ranged between 26.00-33.40C, 170.43-790.02 mho/cm,30.52-116.68 mg/l ,28.05-61.95mg/l ,0.02-0.99mg/l in polluted areas and 25-27.85C,...