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**Filtration Process**:
– Filtration separates solid matter and fluid using a filter medium.
– Oversize particles are retained, while fluid passes through as filtrate.
– Blinding can occur when particles block the filter lattice.
– Effective pore size determines the largest particles passing through.
– Filtration is used in biological, geological, and industrial systems.

**Filtration Methods**:
– Hot filtration prevents crystal formation in a hot solution.
– Cold filtration rapidly cools the solution to form small crystals.
– Vacuum filtration dries small crystals quickly using a Büchner funnel.
– Centrifugal filtration separates dense material from less dense by rotation.
– Filtration methods vary based on the interaction with the filter.

**Filtration Applications**:
– Filtration is used in chemical engineering for material separation.
– Biofilters combine filtration with biological digestion.
– Sieving and filtration differ in particle retention mechanisms.
– Adsorption relies on surface charge for separation.
– Biological filters trap particulates and release metabolites.

**Filtration Techniques**:
– Hot filtration prevents crystallization in the filter funnel.
– Cold filtration cools the solution rapidly to form small crystals.
– Vacuum filtration dries small crystals quickly using a Büchner funnel.
– Centrifugal filtration separates materials by rapid rotation.
– Gravity filtration uses gravity to pass liquid through a filter.

**Filtration in Various Systems**:
– Filtration in animals like humans removes waste from blood.
Water and sewage treatment use filtration to remove undesirable constituents.
– Slow sand filters and trickling filters are examples of filtration systems.
– Filter feeders like baleen whales and sharks use filtration to feed.
– Filtration removes chemical species and biological organisms from fluid.

Filtration (Wikipedia)

Filtration is a physical separation process that separates solid matter and fluid from a mixture using a filter medium that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter medium are described as oversize and the fluid that passes through is called the filtrate. Oversize particles may form a filter cake on top of the filter and may also block the filter lattice, preventing the fluid phase from crossing the filter, known as blinding. The size of the largest particles that can successfully pass through a filter is called the effective pore size of that filter. The separation of solid and fluid is imperfect; solids will be contaminated with some fluid and filtrate will contain fine particles (depending on the pore size, filter thickness and biological activity). Filtration occurs both in nature and in engineered systems; there are biological, geological, and industrial forms.

Diagram of simple filtration: oversize particles in the feed cannot pass through the lattice structure of the filter, while fluid and small particles pass through, becoming filtrate.

Filtration is also used to describe biological and physical systems that not only separate solids from a fluid stream but also remove chemical species and biological organisms by entrainment, phagocytosis, adsorption and absorption. Examples include slow sand filters and trickling filters. It is also used as a general term for macrophage in which organisms use a variety of means to filter small food particles from their environment. Examples range from the microscopic Vorticella up to the basking shark, one of the largest fishes, and the baleen whales, all of which are described as filter feeders.

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