Difference Between Osmosis and Dialysis

Osmosis vs Dialysis

Those who are students of science know about osmosis which is an important biological process going on inside the cells of all plants and animals. This is the process of passage of water from a semi permeable membrane from an area of high water concentration to an area of low water concentration. Most people however know the word reverse osmosis courtesy water purification companies today. There is another term dialysis which is a dread word for many as it refers to the help given to a patient who has suffered from renal failure as his kidneys cannot purify blood on their own. Both being cleaning processes, it is interesting to know what separates these two processes. This article attempts to highlight the differences between osmosis and dialysis.

What is Osmosis?

Osmosis of diffusion of water molecules across a selective semi permeable membrane (cell membrane is one such barrier) that allows passage of water from area of low concentration of solute to are of high concentration of solute. This process is unique in the sense that this barrier does not allow passage of larger molecules like starch and protein. Thus osmosis involves passage of solvent from one side of the membrane to the other side.

What is Dialysis?

On the other hand, dialysis is the process of purification of blood by the kidneys where waste material from blood is excreted from the kidneys thereby purifying the blood. It is thus selective passage of solute.

Difference Between Osmosis and Dialysis

The concepts of osmosis and dialysis find important applications in the field of water purification and medicine. Osmosis tells us how a man who drinks salty ocean water gets dehydrated and dies. The same concept applies of freshwater fish when it is put in salty backwaters or in a ocean. Water treatment plants and clinical analysis and sterilization processes make use of osmosis to remove dissolved impurities in water.

Dialysis is mostly used to provide help to patients who suffer from kidney failure as their kidneys cannot perform blood purification on their own. This is known as hemodialysis where blood from the arteries of the patient is sent through a machine called hemodialyzer (artificial kidney) that removes impurities and waste material from the blood and the blood is sent back to the arteries. There is another process called peritoneal dialysis where the blood is purified inside the body of the patient. The machine that purifies blood makes use of all three process called diffusion ultrafiltration and osmosis to come up with purified blood. Though dialysis is vital for patients suffering from renal failure, it is an artificial process and only a substitute of natural purification of blood by kidneys. Dialysis fails to produce a hormone for the regulation of red cell production inside the body that takes place naturally during blood purification by kidneys.

In brief:

Osmosis vs Dialysis

• While both osmosis and dialysis are purification processes, it is the solvent that passes through the semi permeable membrane in case of osmosis; it is solute that passes through the membrane during dialysis

• Osmosis is used in many fields of nutrition and medicine for purification of water whereas dialysis is mainly used to purify the blood of the patients who suffer from renal failure