Summit Chemical Specialty Products manufactures a full line of enhanced aluminum chemicals for use in water treatment and wastewater treatment, including polyaluminum chloride (PAC or PACl). These products are prehydrolyzed polymerized enhanced aluminum chemicals with a generic formula of Al2(OH)xCl6-x.
An industry innovator for more than 50 years, Summit pioneered the use of a unique high-basicity PACl called aluminum chlorohydrate (ACH). PACl and ACH products vary in aluminum content, chloride content, overall solids content, pH and density. In addition, PACl products are classified by their basicity. As shown in the generic formula Al2(OH)xCl6-x, the basicity of the PACl is defined as (x/6)*100. (For example, the generic formula Al2(OH)3Cl3, indicates a basicity of 50% (3/6)). Although these chemical parameters are important in classifying various types of PACl, they are not necessarily the most important factors. Molecular weight distribution and cationic charge density are critical in determining how the PACl functions as a coagulant in water treatment.
Traditional metal salt coagulants (e.g., alum, ferric) remove impurities from water through a mechanism called sweep-floc. The aluminum or iron ion reacts with alkalinity in the water to form a metal hydroxide floc. This gelatinous floc then entraps particulates in the water and “sweeps” them out while settling. The sweep-floc entrains a great deal of water and the floc is very difficult to dewater. In addition, the use of traditional metal salt coagulants greatly reduces the pH of the treated water, requiring the addition on lime or caustic after treatment. In many cases, if the alkalinity is too low, the water to be treated must be prelimed for adequate treatment to take place.
These pitfalls are eliminated or greatly reduced by the use of PACl. PACl reacts with impurities in water through charge neutralization. Particulates in water are anionic in nature. They interact with the cationic PACl to form flocs which are removed from the water via settling and/or filtration. Because PACl is prehydrolysed, its effect on the pH of the treated water is minimal, which can result in the elimination or reduction of pH adjustment chemicals. The resultant floc is very tight and dewaters easily, greatly reducing the amount of sludge generated.
Molecular weight distribution and charge density are a function of the manufacturing process and the raw materials used in the production of the PACl. Summit uses only virgin raw materials in our production facilities. Because of the extremely high purity of Summit PACl, it can be safely dosed into drinking water at 250 mg/L - the maximum dosage allowed by NSF International. In addition, Summit was the first manufacturer of aluminum chlorhydrate to obtain NSF certification for drinking water additives.
Summit’s unique manufacturing process allows us to tailor a product with the exact molecular weight and charge density required for your specific application. This ensures that our products provide superior performance for your application. This is critical to ensure that the PACl dosage provides maximum benefits at a minimized cost.
Summit has a fully equipped applications lab and a staff of highly qualified application chemists who can assist you in your product selection.
Contact us today to find out how we can meet your water and waste water treatment needs.
