Aluminum is present in nearly all natural water as a soluble salt, a colloid, or an insoluble compound due to its vast occurrence in minerals, rocks, and clays. Aluminum's occurrence in natural waters is controlled by pH and by very finely suspended mineral particles. The cation Al3+ predominates at pH less than 4. Above neutral pH, the predominant dissolved form is Al(OH)4−. Aluminum is nonessential for plants and animals. Aluminum and its alloys are also used in a variety of products, such as heat exchangers, aircraft parts, building materials, containers, etc.
Aluminum potassium sulfate (alum) is commonly used during water treatment processes to flocculate suspended particles, but it can leave a residue of aluminum in the finished water. When concentrations are greater than 0.2 mg/L, water has color, but does not cause significant human health effects. For this reason the U.S. EPA has set a secondary minimum contaminant level (SMCL) of 0.05 mg/L to 0.2 mg/L for aluminum.
Hanna Instrument meters use an adaptation of the Aluminon Method to measure aluminum levels in water. The Aluminon indicator combines with aluminum in the sample, forming a red-orange color proportional to the aluminum concentration.
Below are the most common products used for aluminum measurement.
Benchtop Photometers & Spectrophotometers
Benchtop photometers include multiparameter photometers for drinking water treatment, wastewater treatment and boiler & cooling towers. Each benchtop photometer has methods specific to the industry pre-programmed into the meter. Spectrophotometers, like benchtop photometers, have pre-programmed methods for aluminum but also allows the ability to develop custom methods.
Our benchtop photometers include a digital pH electrode input that allows your photometer to double as a professional pH meter.
Portable photometers offer the convenience of measuring in the field or in a factory. The portable photometers are available as a meter only option or as a kit that includes a rugged carrying case and CAL-Check standards, used to verify the performance of the meter and re-calibration if necessary.
Solutions for aluminum measurement include CAL Check standards for verifying and , if needed, the calibration of our portable photometers. Each CAL Check standard is supplied with a Certificate of Analysis stating the accuracy and traceability of the standard.
Accessories include spare cuvettes and caps for photometers.