WATER TREATMENT APPLICATIONS
Ever wonder how we manage to have safe drinking water flowing out of our faucets? You can thank aluminum sulfate. Municipal water suppliers, such as your local water utility company, make use of alum to treat water for human consumption. In addition, process water (non-drinking water) may also be treated with this chemical for purification when bacteria / sediment would cause an adverse effect.
When added to water, aluminum sulfate causes microscopic impurities to clump together into larger and larger particles. These clumps then settle to the bottom of the container and can be filtered out. This makes the water safer to drink. On the same principle, alum is also sometimes used in swimming pools to decrease water cloudiness (6).
DYEING FABRICS
Look down at your shirt. It’s likely not a plain white t-shirt. Another of the many uses of Aluminum sulfate is in dyeing and printing on cloth. When dissolved in a large amount of water that has a neutral or slightly alkaline pH, the compound produces a gooey substance, Aluminum hydroxide. This goo helps dyes stick to the cloth fibers by making the dye water insoluble. The role of Aluminum sulfate, then, is as a dye “fixer,” which means that it combines with the molecular structure of the dye and the fabric so the dye doesn’t run out when the fabric gets wet (6).
PAPER MAKING
In the past, aluminum sulfate was used in making paper, although synthetic agents have mostly replaced it. Aluminum sulfate helps to size the paper. In this process, it is combined with rosin soap to change the absorbency of the paper, which changes the paper’s ink-absorbing properties. Aluminum sulfate produces acidic conditions, whereas synthetic sizing agents produce acid-free paper which does not break down as easily (6).
MEDICAL APPLICATIONS
Going to the doctor’s office is never fun, but because of aluminum sulfate, the medical field has been able to advance in several ways to keep us healthy. Aluminum sulfate has several practical uses in the medical field. It is primarily used as a coagulating agent in treating minor cuts and abrasions as well as deodorant (due to its antibacterial properties). This compound also adsorbs and precipitates protein antigens in solution; the resulting precipitate improves vaccine immunogenicity by facilitating the slow release of antigen from the vaccine depot formed at the site of inoculation (1). Solutions containing 5 to 10% have been used as local applications to ulcers and to arrest foul discharges from mucous surfaces (2). Aluminum sulfate is found in materials used in the pharmaceutical industry. For instance, It is used in the preparation of aluminium acetate ear drops (2).
FOOD INDUSTRY APPLICATIONS
Alum is used for multiple purposes in the food we eat and is generally recognized as safe when used in accordance with good manufacturing practice (2). It is soluble in water and is mainly used as a thickener and emulsifier (3).
Alum can also be used to:
- Remineralize and clarify water for soft drinks and beer
- Control pH levels in beets, tomatoes, and other vegetables
- Purification of sugar beet juices
- Control pH and color wine and liquor
- Act as a leavening agent in cake mix (baking soda)
- Curdle and thicken cheese (4).
Post time: Nov-23-2019