Q1: Which of the following represents the plot of filtrate volume versus time for constant pressure filtration ?

ANS:A - Parabola

A parabolic shape for the plot of filtrate volume versus time is typically associated with constant rate filtration, not constant pressure filtration. Here’s an explanation of constant rate filtration and why it forms a parabolic curve:

Constant Rate Filtration:

1. Definition:
   • In constant rate filtration, the rate at which filtrate (liquid) passes through the filter medium remains constant over time.
   • This constant rate is typically achieved by applying a constant pressure drop across the filter medium.
2. Filtration Process:
   • Initially, during the early stages of constant rate filtration, the filtrate volume increases rapidly with time.
   • As the filter cake (solid material accumulating on the filter medium) thickens, the rate of filtration gradually decreases.
   • This results in a parabolic relationship between filtrate volume and time, where the filtrate volume increases rapidly at first and then more gradually as filtration continues.
3. Shape of the Plot:
   • The parabolic curve indicates that the rate of filtration is decreasing over time as the filter cake builds up and resistance to flow increases.
   • Mathematically, the parabolic shape can be represented by the equation that describes how the filtrate volume accumulates over time under constant rate conditions.

Constant Pressure Filtration:

• In contrast to constant rate filtration, constant pressure filtration refers to a process where the pressure applied to the filtration system remains constant.
• Under constant pressure, the rate of filtration may vary initially but stabilizes over time as the filter cake develops and the resistance to flow reaches equilibrium.
• The plot of filtrate volume versus time in constant pressure filtration typically forms a straight line because the rate of filtration remains constant once equilibrium is reached under the constant pressure condition.