以上海苏州河支流——蒲汇塘的富磷底泥为试验对象,研究高锰酸钾、双氧水、过氧化钙和硝酸钙4种稳定剂对底泥中磷元素释放的抑制效果。结果表明:高锰酸钾和双氧水对磷的抑制作用持续时间较短,过氧化钙能够快速将底泥的NaOH-P转化为永久性HCI-P,而硝酸钙对磷的转化速度相对较为缓慢;投加过氧化钙可以将孔隙水中正磷酸根的浓度从2.815mg/L降低至0.003mg/L.硝酸钙也可将其值从2.813mg/L降至0.094mg/L;经过氧化钙和硝酸钙处理后,上覆水总磷含量分别可达到0.029mg/L和0.028mg/L,能够满足国家地表Ⅱ类水质要求。因此,过氧化钙和硝酸钙可以作为抑制底泥磷释放的稳定剂使用。
As some stabilizers may inhibit releasing of phosphorus from river sediments, the inhibiting effects of KMnO4, H2O2, CaO2 and Ca(NO3)2 were investigated. It was found that the inhibiting effects of KMnO4 and H2O2 on phosphorus were not permanent, and the stabilizer CaO2 could transform NaOH-P on sediment into permanent HCI-P rapidly, whilst the transforming rate of Ca(NO3)2 was lower. The concentration of PO4^3- in pore water would drop from 2.815 mg/L down to 0.003 mg/L by adding CaO2, or would do from 2.813 mg/L to 0.093 6 mg/L by adding Ca(NO3)2. The total phosphorus concentration in water column could reach 0.029 mg/L and 0.028 mg/L after being treated by CaO2 and Ca(NO3)2, respectively, so as to satisfy the requirement of the Category I! according to the Environmental Quality Standard for Surface Water. Therefore, CaO2 or Ca(NO3)2 could be used as a stabilizer to inhibit phosphorus releasing from sediments.