Match the following in Column I with Column II.
Thus, the correct matching is:
1 - D, 2 - B, 3 - E, 4 - A.
The theoretical aerobic oxidation of biomass (C5H7O2N) is\[ \mathrm{C_5H_7O_2N + 5\,O_2 \rightarrow 5\,CO_2 + NH_3 + 2\,H_2O} \] Given a first-order biochemical oxidation with $k=0.23\ \text{d}^{-1}$ at $20^{\circ}$C (base $e$) and neglecting the second-stage oxygen demand, find the ratio BOD5 at $20^{\circ}$C to TOC (round to two decimals). Atomic weights: C=12, H=1, O=16, N=14 g/mol
A system of seven river segments is shown. Given: $Q_1=5$ m$^3$/s, $Q_2=15$ m$^3$/s, $Q_4=3$ m$^3$/s (outflow), $Q_6=8$ m$^3$/s; $C_1=8$ kg/m$^3$, $C_2=12$ kg/m$^3$, $C_6=10$ kg/m$^3$. Assume complete mixing at junctions, no gains/losses otherwise, steady state. Find the pollutant concentration in segment $R_7$ (in kg/m$^3$, rounded to two decimals).
The cross-section of a small river is sub-divided into seven segments of width 1.5 m each. The average depth, and velocity at different depths were measured during a field campaign at the middle of each segment width. The discharge computed by the velocity area method for the given data is m$^3$/s (round off to one decimal place).}