Sarwoko Mangkoedihardjo : The Kinetics of biodeconcentration for nitrate: Case study for microbial denitrification and plant absorption
Prof. Dr. Ir. Sarwoko Mangkoedihardjo MScES
This research was conducted to study the kinetics processes of microbial denitrification and the kinetics processes of plant absorption. The test plants were spinach, peanut and grass. The test solution contained nitrate of 24 mg N/L, glucose of 64 mg C6H12O6/L and phosphate of 0.5 mg P/L. The results showed that the kinetics of nitrate biodeconcentration processes were exponential: Ct = Co*e-kt. The rate constant for microbial denitrification was stated as kd which was equal to 0.0786 day-1. The rate constant of plant absorption was stated as ks, and the rates for spinach, peanut and elephant grass were 0.0745, 0.0921 and 0.1226 day-1, respectively. The time to process 50 % of nitrate biodeconcentration efficiency (t½), as the half time of nitrate biodeconcentration, for microbial denitrification it was 8.8 days and for nitrate absorption by spinach, peanut, and elephant grass, the times were 9.2, 7.5, and 5.6 days, respectively. Therefore, elephant grass they was more effective in suppressing nitrate than peanut, denitrifier and spinach.