Preparation Of A CaO₂-based Oxygen Slow-Releasing Material And Its Inhibiting Mechanism Of Phosphorus Release In Sediment

In this sdudy, stearic acid and PEG4000 were used to embed the calcium peroxide powders under anhydrous conditions for preparing a novel oxygen slow-releasing material. The infrared spectroscopy and scanning electron microscopy confirmed that stearic acid, PEG4000 and calcium peroxide can be effectively embedded.The experiment proved that the tablet-shape oxygen slow-releasing material did stronger mechanical strength and smaller oxygen release rate than the natural-shape material and short columnar-shape material. Based on the test in aseptic and oxygen-free water, it was found that the oxygen release rate decreased with the increase of stearic acid concentration and PEG4000 concentration, and the pH value also leveled off. The oxygen slow-releasing material can release oxygen slowly in water to increase the dissolved oxygen concentration and inhibit the pollutants releasing in sediment.The results from the simulation sediment show that, with CaO2 dosage of 1.0kg/m2, the tablet-shape oxygen slow-releasing material (stearic acid content of 1.2%) maintained the dissolved oxygen concentration above 4.0mg/L within 35 days at 25℃, and pH value was about 7.7. The Fe-P releasing was inhibited and the concentration of Ca-P, Al-P and Fe-P in sediment increased. The total phosphorus concentration in overlying water reduced to 0.28mg/L from 0.50mg/L.