Drip Line Irrigation - Kleen Flo™
Kleen Flo™ is a water soluble blend of sequestering and chelating agents and surfactants used to prevent emitter plugging from iron calcium carbonate and magnesium.
Kleen Flo™ reacts with ferrous iron to form a stable complex by the process of chelation. Because the resulting complex is soluble, the iron is transferred out of the system before it can oxidize to the fouling, ferric iron state. Also, because the iron is now part of a stable complex compound, it is no longer available to contribute to the formation of iron carbonate or iron phosphate scales. Without getting technical, think of chelating agents as being similar to an ion exchanger (water softener). Chelating agents have unshared electron pairs which, in aqueous solutions readily join with metal ions, forming new complex compounds which are soluble and suppress the potentially troublesome reactions of the metals present, iron in this case.
Calcium carbonate scale is prevented in the same manner as iron above. However, Kleen Flo™ also inhibits scale formation through the "threshold effect". Threshold inhibition prevents precipitation of the scalants in supersaturated solutions by the addition of very small amounts of inhibitor in relation to the amount of calcium present. For example, 2-4 ppm of Kleen Flo™ will prevent scale formation in water with several hundred ppm or more of calcium carbonate present. Kleen Flo™ also contains a surfactant which acts as a wetting agent and antifoulant which helps fluidize solids and keep them moving with the flowing water.
Magnesium is controlled in the same manner as iron and calcium. However, magnesium is typically not a problem unless the pH of the water is above 10.
A well-known disadvantage of the inorganic polyphosphates is their relatively rapid hydrolysis, or reversion, to orthophosphate. This reversion destroys scale inhibition and creates the additional problem of calcium orthophosphate scale formation. The rate at which reversion occurs depends on pH and temperature and is catalyzed by the presence of heavy metals (iron) or algae. Because Kleen Flo™ utilizes a phosphonate compound instead of polyphosphate, it is more stable and resistant to decomposition, even at elevated temperatures. Polyphosphate products will actually decompose in their drums if pumping locations are not shaded from the sun.
Inorganic polyphosphates have been used for scale inhibition since the 1930's. However they are not always the product of choice because of their instability.
Kleen Flo™ contains six active ingredients, which provides a synergistic blend of deposit and antifouling protection.
Phosphoric acid has limited effectiveness as a cleaner because its calcium salts are insoluble and its iron salts are relatively insoluble in low strength phosphoric acid solutions. Sulfuric acid effectively removes iron deposits but forms insoluble calcium sulfate with the commonly occurring calcium carbonate. While some deposits may be removed, others may be formed during the cleaning. These acids are also dangerous to personnel and equipment and require proper handling and storage.