The Use Of Calcium-phosphorus Mineral Water Removal And The Mechanism Discussed

Eutrophication of lakes and reservoirs has generally gained people's attention. Countries all over the world have exerted great efferts to deal with this problem. Eutrophication is in fact a kind of environmental pollution caused by the excessive reproduction of algae (blue green algae). Blue green algae live on a number of elements, among which phosphorus is regarded as the leading factor of eutrophication. There are a lot of ways to deal with eutrofication. Using these methods, water quality has improved to a certain extant, but the reduction of phosphorus concentration can't reach the satisfactory level. In the eutrophication water. There is always enough phosphorus to make the algae grow. fluorapatite and carbonate-fluorapatite are steady which have very low solubility. It is the active phosphorus that can cause eutrophication. We will cut the nutrition source and control eutrophication if we make the active phosphorus into inactive one again. Crystalization method is an induction of phosphorus into stable phosphate on the crystal surface. The purpose of this study is make the active phosphorus transform into fluorapatite or carbonate-fluorapatite by adding fluorin, calcium and crystal into the water. The outcome of our 18-month long experiment is as follows: calcite and phosphorite are all efficacious in the process of phosphorus reduction in the solution, which proved their indispensable function in the study; Phosphorite is better than calcite in phosphorus reduction, indicating its advantage in the experiment; It is easier to get good result in solution with high content of phosphorus, which means there are some difficulties in phosphorus reduction in solution with very low content of phosphorus; Temperature and the potential of hydrogen affect the reaction greatly: High temperature and basic condition can markedly facilitate the phosphorus reduction. The reduction rate can be more than 99% in these two situations. The reaction is more quickly if the solution is heated and is more thoroughly under basic condition. The final result is: adding the fluorin, calcium and the crystal of phosphorite into the water plus some heating process, or under relatively basic condition without heating can make the concentration of phosphorus reduce to satisfactorily level within 10 hours and 5 days respectively. It will get the best result when the mass ratio of calcium, phosphorus and fluorin is 11:3:2.2 with 900mg/400ml of the crystal of phosphorite. The final concentration of phosphorus can be less than 0.001ppm, which is far below the base line(0.02ppm) of eutrofication. There is certain degree of the dissolution of phosphorus from the surface of phosphorite after about two months, which means the solid product may include some unstable compound or complex instead of sheer crystal.