以香溪河流域磷矿废渣堆堑体为研究对象,采用美国EPA Method 1313浸出实验方法,揭示了不同环境pH条件下磷矿废渣中所含磷素(以总磷计)在固-液相间的分配特性,基于实验结果与磷矿废渣堆堑体的实际情况,分析了磷矿废渣对当地酸雨的缓冲能力,并依据渗滤控制模型对磷矿废渣堆堑体在100年间的磷素累积释放量进行了预测.结果表明,在磷矿废渣中所含碳酸盐和硅酸盐矿物对酸雨所形成的缓冲作用下,废渣堆堑内部环境p H值将长期维持在弱碱性范围内;尽管碱性环境不利于磷素的浸出,但在弱碱性条件下磷矿废渣浸出液中的总磷浓度仍然超过国家标准所规定的最高排放浓度限值;磷矿废渣在100年间的磷素累积释放率为4.9 mg·kg^-1,对其附近的水体可以形成磷素的点源污染.
The phosphate waste rock pile deposite,which was located in Xiangxi River watershed,was selected as the research subject. The liquid-solid partitioning as a function of pH for phosphorus element,which calculated as total phosphorus,in phosphate waste rocks were tested according to EPA Method 1313. The phosphate waste rock buffering capacity for local acid rain was analyzed and then the cumulative released mass of phosphorus element during one hundred years was estimated based on the Percolation Control Model. The results indicate that the inner environment of phosphate waste rock pile would be maintained in the weakly alkaline range due to the carbonate and silicate minerals buffering effects. Although the weakly alkaline environment would limit the leaching of phosphorus element from phosphate waste rock,the total phosphorus concentrations of eluates still exceed the highest emission concentration limits specified in the China national standard. The cumulative released phosphorus mass from waste rock pile during one hundred years is 4.9 mg·kg^-1,which can form a point source pollution for water body nearby the waste rock pile.