Abstract:
At 'Maitri' drinking water source is Priyadarshini Lake which is situated at 200 m away from the station. Water consumption leads to wastewater generation and to treat the waste water two rotating biological contactors (RBC), B1 and B3 of different capacity were installed. The maximum treatment capacity of B3 RBC is 5 kl/d and B1:RBC is having capacity of 1 kl/d. At the sampling point temperature, pH was measured and within 15 min of sampling it was brought to the laboratory at Maitri to analyse basic parameters, ie, BOD, COD, conductivity, TSS, Cl, NH3-N, DO, total alkalinity and turbidity. The treatment efficacy of B1:RBC was observed only 66.7 percent in terms of BOD and 68.9 percent of COD. But, due to lower pH, the ammonia nitrogen of effluent was less than the influent because the ammonia producing bacteria were notworking effectively at lower pH. Tertiary treatment at lab scale of B1 RBC shows that BOD and COD are further removed by 40.3 and 21.9 percent, respectively. The treatment efficacy of B3:RBC was observed only 29.8 percent in terms of BOD and 41.4 percent of COD. The BOD and COD were further removed by 22.2 and 30 percent, respectively in tertiary treatment of B3 RBC at lab scale experiment. The tertiary treatment was found to be very effective even when the treatment system was not tuned fully, however, if tuned and tertiary treatment system was applied further the efficacy improvisation would have been expected upto 95-98 percent.
