# A surface water treatment plant operates round the clock with a flow rate of $35 \mathrm{~m} / \mathrm{min}$. The water temperature is $15^{\circ} \mathrm{C}$ and jar testing indicated an alum dosage of $25 \mathrm{mg} / 1$ with flocculation at a $G t$ value of $4 \times 10^{4}$ producing optimal results. The alum quantity required for 30 days (in $\mathrm{kg}$ ) of operation of the plant is

## Question ID - 156444 :- A surface water treatment plant operates round the clock with a flow rate of $35 \mathrm{~m} / \mathrm{min}$. The water temperature is $15^{\circ} \mathrm{C}$ and jar testing indicated an alum dosage of $25 \mathrm{mg} / 1$ with flocculation at a $G t$ value of $4 \times 10^{4}$ producing optimal results. The alum quantity required for 30 days (in $\mathrm{kg}$ ) of operation of the plant is

3537

37800-37800

Next Question :

A chiller working on mechanical vapour compression refrigeration system $(\mathrm{COP}=4.5)$ is used for cooling $12500 \mathrm{~kg}$ of fresh cow milk $\left(\mathrm{c}_{\mathrm{p}}=3.8 \mathrm{~kJ} \mathrm{~kg}^{-1} \mathrm{~K}^{-1}\right)$ from $30^{\circ} \mathrm{C}$ to $4{ }^{\circ} \mathrm{C}$ in 3 hours. Assuming ideal compression process, the power consumed by the electric motor in $\mathrm{kW}$ and the tonnage of refrigeration (TR), respectively are
(A) 25.4 and 32.5
(B) 25.4 and 114.3
(C) 32.5 and 25.4
(D) 114.3 and 25.4 