A number of bench scale reactors were operated in the laboratory as completely mixed reactors with recycle, to determine kinetic coefficients for a wastewater. The reactors were operated at the same HRT (θ) and initial soluble substrate concentrations but at different SRT (θc) values. The initial soluble substrate concentration was 500 mg COD/L. The HRT was 6 h for all the reactors. The experimental data are provided below. Reactor So, mg/L S, mg/L X, mg VVS/L SRT, d
1 500 300 295 0.45
2 500 200 472 0.50
3 500 150 584 0.55
4 500 100 746 0.60
5 500 60 990 0.75
6 500 30 1516 1.05

Required:
Calculate the kinetic coef cients Y and kd.