云南省抚仙湖流域帽天山磷矿区磷流失过程模拟研究

SIMULATION STUDY ON PHOSPHORUS RELEASE OF PHOSPHATE MINED LAND OF MAOTIANSHAN MOUNTAIN IN FUXIANHU WATERSHED

通过批平衡实验和土柱淋溶实验,模拟在环境因子(pH值、降雨频度)的影响下,磷矿石、废土石和废渣中磷的释放规律.结果表明,磷石膏和泥磷中磷的释放受pH值的影响较小,维持较为恒定的高释放量.磷矿石、矿坑沉积物和废土石中磷的解吸受pH值影响,pH值愈低,愈有利于磷的释放;当解吸溶液pH值为3.50时,废土石和磷矿石中磷的释放量仍可达到2.25mg·l-1和3.15mg·l-1.间歇淋溶过程促进了磷矿石、废土石和磷石膏中磷的释放,对废土石中磷的释放作用尤为显著,干燥后再次降雨的释放量比初期降雨高出3倍.帽天山磷矿区大面积裸露的磷矿石剖面、废土石堆场和废渣堆场在酸性溶液的淋溶作用下能够产生大量的磷流失,而且这个过程是持久的,是抚仙湖水质下降的主要因素.

Phosphorus release kinetics from phosphorite, overburden, and waste residues like gypsum and clay phosphorus on the effect of pH and rainy frequency were studied. The combination of batch balance experiments and column leaching was conducted in the present study. The results showed that the amount of P release from gypsum and clay phosphorus remained steady regardless the effect of pH. However, P release from phosphorite, overburden, and sediment were pH dependent. The removals of P from phosphorite and overburden on pH 3.5 solution were 2.25 mg·l^-1 and 3.15 mg·l^-1 , respectively. And the results of column leaching showed that the removals of P from samples especially from overburden were increased when leaching again after drying process. It could be concluded that P release on phosphate mined land was huge and lasting.