Aluminium-based alums have been used since antiquity, and are still important in many industrial processes.

The most widely used alum is potassium alum. It was used since antiquity as a flocculant to clarify turbid liquids, as a mordant in dyeing, and in tanning. It is still widely used in the treatment of water, in medicine, for cosmetics (in deodorant), in food preparation (in baking powder and pickling), and to fire-proof paper and cloth.

It is also used as a styptic, in styptic pencils available from pharmacists, or as an alum block, available from barber shops and gentlemen's outfitters, to stem bleeding from shaving nicks ; and as an astringent. An alum block can be used directly as a perfume-free deodorant (antiperspirant), and unprocessed mineral alum is sold in Indian bazaars for just that purpose. Throughout Island Southeast Asia, potassium alum is most widely known as tawas and has numerous uses. It is used as a traditional antiperspirant and deodorant, and in traditional medicine for open wounds and sores. The crystals are usually ground into a fine powder before using.

Alum is used as a mordant in traditional textiles; and in Indonesia and the Philippines, solutions of tawas, salt, borax, and organic pigments were used to change the color of gold ornaments. In the Philippines, alum crystals were also burned and allowed to drip into a basin of water by babaylan (shamans) for divination. It is also used in other rituals in the animistic anito religions of the islands.

In traditional Japanese art, alum and animal glue were dissolved in water, forming a liquid known as dousa, and used as an undercoat for paper sizing.

Alum in the form of potassium aluminium sulphate or ammonium aluminium sulfate in a concentrated bath of hot water is regularly used by jewelers and machinists to dissolve hardened steel drill bits that have broken off in items made of aluminum, copper, brass, gold (any karat) and silver (both sterling and fine). This is because alum does not react chemically to any significant degree with any of these metals, but will corrode steel. When heat is applied to an alum mixture holding a piece of work that has a drill bit stuck in it, if the lost bit is small enough, it can sometimes be dissolved / removed within hours.

 

Non-Ferric Alum is a purer form of aluminum sulphate. It is used in better grades of paper for loading and sizing purposes. Non-Ferric Alum is manufactured from aluminum trihydrate whereas ferric alum uses bauxite as the raw material. The raw material is cooked with sulphuric acid under suitable conditions. Alum is used for phosphate precipitation in water treatment plants under the process chemical precipitation of phosphate. The influent sewage contains phosphate which is utilized under bio cell synthesis generally knowns as Biological phosphate removal. Excess phosphate remaining after the biological consumption will go out to the receiving water body and will enhance Eutrophication and disturb the local ecology. To reduce the outlet phosphate additional method of chemical precipitation is used which requires metal salt dosing.

 

 

Metal salt will react with phosphate to form metal phosphate molecules and will settles down in the biological aeration basin during the settling phase and will be removed from the system during SAS pump operation.

 

 

 

Treated effluent for reuse shall be dosed with Sodium hypochlorite after UV disinfection to meet reuse water quality requirement of 1 mg/l. Sodium Hypochlorite is being used as disinfectant, it is highly reactive and oxidizes the virus and bacteria available in the water.

 

 

Treated water tank shall be utilized for sodium hypochlorite contact. Entire assembly of Sodium hypochlorite storage and dosing system is provided.

 

 

 

 

Polyelectrolytes are polymers whose repeating units bear an electrolyte group. Polycations and polyanions are polyelectrolytes. These groups dissociate in aqueous solutions (water), making the polymers charged. In general, polyelectrolytes may have various kinds of such groups. Homogeneous polyelectrolytes have only one kind of charged group, e. g. only carboxylate groups. If both negative (anionic) and positive (cationic) groups occur, we call such a molecule a polyampholyte.

 

 

Polyelectrolyte flocculation has been widely employed to pretreat slurries for increasing its settleability and the corresponding filterability