Applications of Colloids are unlimited. Colloids find its applications in everyday life phenomena. Some of important applications of colloids are discussed.
Purification of water
Water contains colloidal impurities .These impurities can be weeded out by using electrolyte like Alum. Alum is positively charged Al3+ ion which attracts negatively charged colloidal impurities. These neutralized particles settle down and pure water is decanted off. Thus Alum is used to remove dirt and impurities present in the colloidal solution.
Large numbers of food articles which we use in our daily life are colloidal in nature. For example, milk, butter and ice creams are colloidal in nature.
Most of the medicines are colloidal in nature. Colloidal calcium and gold are administered by injections to raise the vitality of human system.
Smoke Precipitation using Cottrell precipitator
Colloidal particles of Smoke and dust are major source of pollution in big industrial cities. Smoke precipitation is technique of precipitating smoke particles present in air.
Smoke particles are the electrically charged colloidal particle suspended in air. To remove these particles from air, Cottrell precipitator is used. Cottrell precipitator uses principle of electrophoreses (movement of colloidal particles under influence of electric field) to weed out smoke particles. Air containing smoke and dust particles are allowed to pass through metal electrodes present inside Cottrell precipitator. These charged particles moves towards oppositely charged electrodes and get deposited there from which they are scrapped mechanically.
Dirt and mud particles are electrically charged. By applying electric field in sewage tank, dirt particles reach the oppositely charged electrode, get neutralized and are coagulated. These coagulated particles are suspended in solution and are easily removed.
Colloids find another application in producing artificial rain. Cloud consists of charged particles of water dispersed in air. These particles are neutralized by spraying oppositely charged particles over a cloud. These neutralized particles of water combine to form large water drops. Thus, artificial rain is caused by the aggregation of minute particles of water to form large particles.