ASSESSMENT OF POST-BIOMETHANATED DISTILLERY EFFLUENT MOVEMENT ON GROUND WATER QUALITY USING PIEZOMETERS
To monitor the downward movement of post bio-methanated distillery effluent (PME) and possible ground water contamination, piezometers were installed at different depths viz., 0.5, 1.0, 1.5 and 2.0 m in the long term sugarcane field experiments being conducted at EID Parry (I) Ltd., Cane farm, Edayanvelli, Tamil Nadu. The piezometers were installed in pre-plant undiluted PME (5 lakh litres ha-1) applied field, diluted PME (1:10 times) applied field and in control plot (without PME application). Three replications were maintained for each treatment. Piezometers were examined for the presence of leachate every month. The leachate samples were analyzed for pH, EC, cations, anions, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), biological oxygen demand (BOD) and chemical oxygen demand (COD). The analysis of the leachate samples revealed no change in color at all the depths. The BOD and COD of the leachate from PME plots when compared to the control plots were not affected significantly at all the depths. There was not any significant difference observed in the pH, EC, cations like Ca, Mg and K and anions like Cl, CO3, HCO3 and SO4 in the leachate collected beyond 1.5m depths in treated plots when compared to the control plots. The SAR calculated at 0.5m and 1.0m depths of treated plots has stood below the control values. The higher Ca and Mg in the leachate supplied by the PME applied have significantly decreased the SAR of the leachate at these depths. The SAR of leachate collected at 2.0 m depths in the treated plots did not show any significant difference from the control plots. The RSC calculated was found to be lesser than the control plots till 1.0m depths this is due to the higher Ca and Mg found in the leachate. The results reveal that the PME application has not influenced the leachate collected at 1.5m and 2.0m depths in the treated plots and this clearly indicates that PME applied at the highest concentrations has not influenced the ground water and there is no possibility of pollution by the PME application at these doses.
B. Anandakrishnan, M. Baskar, M. Soundarrajan, M. Sheik Dawood, S. Jebaraj and R. pushpavalli