Filtration is a process used to separate solids from liquids or gases by passing them through a porous medium. The action of filtration involves the removal of particulate matter, which can be achieved through various mechanisms. In this case, the correct option is D) Electrolytic action.

Electrolytic action in filtration:
- Electrolytic action refers to the use of an electric current to facilitate the removal of particulate matter from a liquid or gas stream during the filtration process.
- This method is commonly used in applications where the particulate matter is composed of charged particles, such as ions or colloidal particles.
- The electric current applied during electrolytic action helps to attract and remove these charged particles from the liquid or gas stream.
- The process typically involves the use of electrodes, which are connected to a power source and placed in the filtration system.
- The electrodes can be made of materials that are either negatively charged (cathode) or positively charged (anode).
- When the electric current is applied, the charged particles in the liquid or gas stream are attracted to the electrodes with opposite charges.
- As a result, the particulate matter is effectively removed from the stream and deposited onto the electrodes.
- The electrodes can then be cleaned or replaced to ensure continuous and efficient filtration.

Advantages of electrolytic action in filtration:
- Electrolytic action offers several advantages in filtration processes:
- Enhanced particulate removal: The use of an electric current helps to improve the removal efficiency of charged particles, which may be difficult to remove by other methods such as mechanical straining or sedimentation.
- Selective removal: Electrolytic action allows for the selective removal of specific types of particles based on their charge. This can be useful in applications where the removal of certain contaminants or impurities is required.
- Continuous operation: The electrolytic action can be applied continuously during the filtration process, ensuring a consistent removal of particulate matter over time.
- Scalability: Electrolytic filtration systems can be designed to accommodate various flow rates and volumes, making them suitable for both small-scale and large-scale applications.

In conclusion, electrolytic action is an effective mechanism for the removal of particulate matter during the filtration process. By utilizing an electric current, charged particles can be attracted and removed from a liquid or gas stream, offering advantages such as enhanced removal efficiency, selective removal, continuous operation, and scalability.