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United States Department of Agriculture

Agricultural Research Service

Title: A Survey of Enzymatic Activity in Commercially Available Pool and Spa Products

item Ripple, Karen
item Condon, Brian
item Hosterman, Kevin
item Williams, Erica
item Garner, Michelle

Submitted to: International Journal of Aquatic Research and Education (IJARE)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2007
Publication Date: 2/1/2007
Citation: Ripple, K., Condon, B.D., Hosterman, K., Williams, E., Garner, M. 2007. A Survey of Enzymatic Activity in Commercially Available Pool and Spa Products. International Journal of Aquatic Research and Education (IJARE). 1(1):21-28.

Interpretive Summary: Traditionally, chlorine or bromine products have been used to maintain pool water free from bacteria, algae, and other contaminants such as oils and nitrogen based materials. Chlorine and bromine have been safe and effective in water purification applications for many years. However, if handled improperly, these chemicals could pose environmental or human safety issues. For these reasons, alternatives or supplements to the use of chlorine and bromine would be beneficial. One alternative is the use of enzymes to break down pool contaminants to aid filtering and reduce film or scum formation. One of these enzymes is a lipase. Lipases are enzymes that break down lipid molecules into simple fatty acids and glycerol. They are naturally occurring molecules produced by plants, animals, bacteria and mold. The lipase enzymes are capable of working in a water and oil emulsion and therefore act at the oil-water interface where chlorine and bromine products often cannot reach or react slowly. Enzymes are catalysts, and as such one enzyme molecule can break down many lipid molecules. This feature allows enzymes to be effective at concentrations well below that required for the chemical interaction of chlorine with the lipids, since chlorine reacts with lipids in a 1:1 ratio. Once the lipid is broken down, the detergents found in the pool products can then solubilize the smaller molecules, allowing them to be filtered out of the pool. Since triglycerides (a type of lipid) are involved in the practical maintenance issues of scum lines, surface films, and filter clogs, the lipase could be especially beneficial in preventing them.

Technical Abstract: Many pool water treatment products currently available commercially claim that they work effectively by possessing enzyme activity (specifically lipase) that degrades common oil (lipid) contaminants found in pool water. Currently, there is no standard in measuring the enzymatic activity of these enzymes containing formulations or the efficacy of these claims. Therefore, we have measured the enzyme activity of several pool water treatment products based on a colorimetric assay that can be read using a microplate reader. Of the 12 products tested, 6 showed significant enzyme activity when tested at formulation concentrations. The enzyme activities observed at in-use concentrations were far lower, to the point of below the detection limit for the activity assay. Since chlorine also has the ability to degrade these oils, it was shown that the enzyme activity does not contribute significantly to lipid degradation beyond the activity of the chlorine alone in dilution based studies.

Last Modified: 10/15/2017
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