Question: Why Alum Is Used As Coagulant?

What is the function of alum?

What is Alum and How Does it Work.

Alum (aluminum sulfate) is a nontoxic liquid that is commonly used in water treatment plants to clarify drinking water.

It’s use in lakes began in the early 1970’s and is used to reduce the amount of phosphorus in the water..

Is alum harmful to fish?

Mixing Alum with water about 8.2 can be toxic to fish. It can be sprinkled as a powder over the water surface, through a waterfall, or through a skimmer intake. … An alum treatment, unfortunately, does not kill algae.

What is the pH of alum?

Alum is most commonly delivered as a liquid concentration, having a solids level of 8.3% as Al2O3 or about 50% as hydrate. Alum solutions are acidic. For instance, a 1% solution has a pH of around 3. Ionic species present in alum solutions are highly dependent on the degree of reaction with hydroxyl ions.

Which is used as coagulant?

The main chemicals used for coagulation are aluminium sulphate (alum), polyaluminium chloride (also known as PAC or liquid alum), alum potash, and iron salts (ferric sulphate or ferric chloride).

Why does alum reduce pH?

While alum and ferric-based coagulants are acidic in nature and produce a drop in pH when added to wastewater, their main purpose is to neutralize electrical charges of fine particles in water and clump them together.

What is the most used coagulant?

Iron and aluminium salts are the most widely used coagulants but salts of other metals such as titanium and zirconium have been found to be highly effective as well.

What does coagulant mean?

Coagulants are a substance which cause particles in a liquid to curdle and clot together. … Coagulation treatment chemicals are used in effluent water treatment processes for solids removal, water clarification, lime softening, sludge thickening, and solids dewatering.

Is alum a coagulant?

Alum is one of the most widely used coagulants in the water treatment industry (Benschoten and Edzwald 1990). For water and wastewater treatment, the coagulants used more frequently are the inorganic salts of aluminum.

Why alum is used in water treatment?

The alum promotes coagulation of fine particles which helps resolve problems of color as well as turbidity. If the process is given enough time to work and is applied properly, it not only corrects problems in the water but actually results in removing most of the aluminum used in the process.

What is coagulant function?

Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization. Inorganic, organic, or a combination of both coagulant types are typically used to treat water for suspended solids removal.

Is Alum safe to use?

Although alum is approved as a food additive by the U.S. Food and Drug Administration, it is toxic in large doses. … Although it is deemed safe enough for this purpose by the Food and Drug Administration, there may be negative health consequences from continued exposure to aluminum ions in the alum.

Does alum kill bacteria?

coli within one hour, and 0.005 per cent, or 500 mg per litre, kills bacteria within one to two hours. Alum precipitates the insoluble materials in the water and kills or lowers the total bacterial content of the water.

What are two uses of alum?

Uses of Alumpurification of drinking water as a chemical styptic pencil to stop bleeding from minor cuts.the adjuvant in vaccines ( a chemical that enhances the immune response)deodorant “rock”pickling agent to help keep pickles crisp.flame retardant.the acidic component of some types of baking powder.More items…•

Can we drink alum water?

RESEARCH FINDINGS the csIro has conducted extensive research in this matter and in late 1998 found convincing evidence that the use of alum to treat drinking water is safe. ALUMINIUM SULFATE OR ALUM IS USED AS A FLOCCULANT TO REMOVE UNWANTED COLOUR AND TURBIDITY FROM WATER SUPPLIES.

Can Alum be used to purify drinking water?

Alum, also known as potassium aluminum sulfate, can be used to purify water. … Alum in its powdered form can be added to water to bind with phosphorous particles to aid the water purification process.