Aluminum Sulfate and its uses

Aluminum sulfate is a salt with the formula Al2(SO4)3, xH2O. It is soluble in water and is mainly used as a coagulating agent in the purification of drinking water and wastewater treatment plants, and also in paper manufacturing.

Aluminum sulfate is sometimes used in the human food industry as a firming agent, where it takes on E number E520, and in animal feed as a bactericide. In the USA, the FDA lists it as “generally recognized as safe” with no limit on concentration. Aluminium sulfate may be used as a deodorant, an astringent, or as a styptic for superficial shaving wounds. Aluminium sulfate is used as a mordant in dyeing and printing textiles.

It is a common vaccine adjuvant and works “by facilitating the slow release of antigen from the vaccine depot formed at the site of inoculation.”


Aluminium sulfate is used in water purification and for chemical phosphorus removal from wastewater. It causes suspended impurities to coagulate into larger particles and then settle to the bottom of the container (or be filtered out) more easily. This process is called coagulation or flocculation.  Aluminum sulfate has been used as a method of eutrophication remediation for shallow lakes. It works by reducing the phosphorus load in the lakes.

When dissolved in a large amount of neutral or slightly alkaline water, aluminum sulfate produces a gelatinous precipitate of aluminum hydroxide, Al(OH)3. In dyeing and printing cloth, the gelatinous precipitate helps the dye adhere to the clothing fibers by rendering the pigment insoluble.

Aluminum sulfate is sometimes used to reduce the pH of garden soil, as it hydrolyzes to form the aluminum hydroxide precipitate and a dilute sulfuric acid solution. An example of what changing the pH level of soil can do to plants is visible when looking at Hydrangea macrophylla. The gardener can add aluminum sulfate to the soil to reduce the pH which in turn will result in the flowers of the Hydrangea turning a different color (blue). The aluminum is what makes the flowers blue; at a higher pH, the aluminum is not available to the plant.

In the construction industry, it is used as waterproofing agent and accelerator in concrete. Another use is a foaming agent in firefighting foam.

It can also be very effective as a molluscicide, killing Spanish slugs.

Fine crystals to large granular Aluminum Sulfate

Aluminum Sulfate Wholesale (Prices and availability):

Wholesale pallet quantities are available for businesses with a commercial address, Forklift and Loading dock. All sizes are available at the same price. 

Each pallet is 2000 lbs. Made in Turkey. Price in July 2022 is $990 per pallet FOB shipping warehouse (New Jersey, Georgia, Texas.)