Effects Of Calcium Magnesium Acetate Research Articles

Influence of De-icers on the Corrosion and Fatigue Behavior of 4140 Steel

The purpose of this test was to evaluate the effects of calcium magnesium acetate (CMA) and sodium chloride (NaCl)—two common substances used to de-ice roadways—on the corrosion and fatigue behavior of annealed AISI 4140 steel. When CMA-corroded, NaCl-corroded, and as-machined samples were tested using R = 0.1, and f = 20 Hz, it was found that, within the scope of this study, samples corroded in both 3.5% CMA solution and 3.5% NaCl solution exhibited a lower fatigue strength than samples tested in the as-machined, uncorroded condition. For the short lives tested in this study, the difference in the effects of CMA and NaCl is minimal. However, at longer lives it is suspected, based on the trends, that the CMA solution would be less detrimental to the fatigue life.

Effects of calcium magnesium acetate (CMA) on dissolved oxygen in natural waters

Comprehensive laboratory and field experiments were performed to determine the potential effects of the experimental deicing agent calcium magnesium acetate (CMA) on aquatic and terrestrial ecosystems. A companion paper covers the overall results of these experiments. This paper concentrates on the leading concern to emerge from the testing, the potential for CMA to deplete dissolved oxygen (DO) in water bodies. In laboratory biochemical oxygen demand (BOD) experiments, 100 mg CMA/1, at the high end of the concentration routinely expected in highway runoff, completely depleted oxygen within 2 days at 20°C. A concentration of 10 mg/1 caused a net depletion of about 4.5 and 7.0 mg O 2/l for reagent-grade and corn-based CMA, respectively. This extra oxygen demand was created by the corn-based CMA even though the two products had equal acetate concentrations. Most of the extra demand can probably be attributed to the presence of butyrate as a contaminant in the corn-based CMA. The rate of DO depletion was strongly dependent on temperature. While the rate appeared to follow an Arrhenius relationship with temperature, the classic, first-order BOD equation did not represent initial DO depletion well at low temperatures. An alternative model was proposed for this region, where depletion better followed a logistic-type curve, probably in direct proportion to the growth of bacteria. Oxygen depletion after CMA additions was also observed in microcosm ecosystems and field ponds, although reaeration reduced net depletion compared to the BOD experiments. When ice covered one of the ponds, a large DO drop occurred following a relatively small CMA inflow. It is recommended that CMA applications be avoided in situations where receiving waters are close to the road, have a low dilution potential, or support populations of fish sensitive to low oxygen levels. Applications during late spring storms and where there is potential for CMA runoff to get into ice-covered water bodies are also discouraged.

Effects of Calcium Magnesium Acetate Deicer on Small Ponds in Interior Alaska

ABSTRACT Whole-lake experiments were conducted on three ponds in interior Alaska to test the effects of calcium magnesium acetate (CMA), an experimental road deicer, on aquatic organisms. The CMA added to the test ponds equalled approximately one chemical application applied to 0.4 km of a typical section of road (one lane) draining entirely to a small pond. Calcium elevation did not persist into the next summer; it may have been flushed out by snowmelt. Acetate from the CMA mixture was apparently rapidly taken up by aquatic organisms and cycled for several months, depleting dissolved oxygen in the water. Dissolved oxygen became extremely low in a small pond of about 2,600 m3 treated with 55 mg/L calcium acetate (calculated from calcium elevation). Bacteria and algae both appeared to be stimulated by CMA additions, as indicated by higher standing crops in treated ponds. The algae were probably stimulated by bacterial metabolism products of the acetate, or by phosphorus in the CMA used. Cladocerans were mo...